JP2014199398A - Polarizing plate protection film, polarizing plate, and liquid crystal display device - Google Patents

Abstract

【選択図】なし[Problem] To provide a polarizing plate protective film which is less colored (yellowing) and has excellent polarizing plate durability even in a high temperature and high humidity environment.
A (meth) acrylic resin and 1 to 20 parts by mass of a specific compound (for example, a phenolic compound represented by the following (A)) with respect to 100 parts by mass of the (meth) acrylic resin Polarizing plate protective film.

[Selection figure] None

Description

  The present invention relates to a polarizing plate protective film, a polarizing plate, and a liquid crystal display device. In particular, the present invention relates to a polarizing plate protective film that is less colored (yellowing) and excellent in polarizing plate durability even in a high temperature and high humidity environment, a polarizing plate including the polarizing plate protective film, and a liquid crystal display device.

  Liquid crystal display devices are increasingly used year by year as space-saving image display devices with low power consumption. As the market for so-called mobile applications such as mobile phones and tablet PCs expands in addition to the market where high-quality images such as televisions are required, the need for thinning has further increased.

  The basic configuration of a liquid crystal display device is one in which polarizing plates are provided on both sides of a liquid crystal cell. The polarizing plate plays a role of allowing only light having a polarization plane in a certain direction to pass through, and the performance of the liquid crystal display device is greatly influenced by the performance of the polarizing plate. The polarizing plate generally has a configuration in which a polarizer made of a polyvinyl alcohol film or the like on which iodine or a dye is adsorbed and oriented, and a transparent protective film are bonded to both the front and back sides of the polarizer. As the polarizing plate protective film, cellulose acetate or acrylic resin is used.

  For example, Patent Document 1 describes a polarizing plate protective film in which a phenol compound is added as an additive to a resin containing an acrylic resin and a cellulose ester resin in a specific ratio.

JP 2010-112987 A

However, it was found that the polarizing plate protective film described in Patent Document 1 has a significantly reduced orthogonal transmittance, that is, poor polarizing plate durability when used for a long time in a high temperature and high humidity environment.
Moreover, when a phenol type compound was used as an additive of a polarizing plate protective film, it turned out that a film is gradually colored yellow (yellowing) depending on the structure and content of a phenol type compound.

  An object of the present invention is to provide a polarizing plate protective film having little coloration (yellowing) and excellent in polarizing plate durability even in a high temperature and high humidity environment, a polarizing plate including the polarizing plate protective film, and a liquid crystal display device Is to provide.

When the present inventors diligently studied for the purpose of solving the above-mentioned problems, a (meth) acrylic resin has a phenolic compound having a specific structure having an alkyl group substituted with an aromatic ring as a substituent. A polarizing plate protective film to which a specific organic acid such as a polymer containing a repeating unit derived from a monomer or a barbituric acid derivative is added at a specific content can suppress coloring, and orthogonal transmittance at high temperature and high humidity over time It was found that the decrease in the temperature can be suppressed.
By using as a polarizing plate protective film a film containing a specific organic acid such as a phenolic compound having a specific structure having an alkyl group substituted with an aromatic ring as a substituent or a barbituric acid derivative, boron in a polarizer is used. Since diffusion of acid-derived boron can be suppressed and the amount of polyiodine ions can be kept large, it is considered that reduction in orthogonal transmittance can be suppressed.

  That is, the said subject is solved by the following structures.

[1]
A (meth) acrylic resin, a compound represented by the following general formula (1), a polymer containing a repeating unit derived from a monomer represented by the following general formula (2), represented by the following general formula (3) And a polarizing plate protective film containing at least one selected from a compound represented by the following general formula (III):
A polymer containing a compound represented by the following general formula (1), a polymer derived from a monomer represented by the following general formula (2), and the following general formula for 100 parts by mass of the (meth) acrylic resin. A polarizing plate protective film comprising 1 to 20 parts by mass of at least one selected from the compound represented by (3) and the compound represented by the following general formula (III).
General formula (1)

(In general formula (1), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aromatic group. R ⁶ , R ⁷ and R ⁸ are each (It may have a substituent.)
General formula (2)

(In the general formula (2), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ² represents a substituent. (A) is necessary to form a 5- or 6-membered ring. Represents an atomic group, and n represents an integer of 0 to 4.)
General formula (3)
X ³ -L- (R ³ ) _m
(In the general formula (3), X ³ represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, R ³ represents a hydrogen atom, and a carbon number of 6 to 30. An alkyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heterocyclic group having 6 to 30 ring members, and further having a substituent. M is 1 when L is a single bond, and m is (valence of L-1) when L is a divalent or higher linking group.
Formula (III)

(In General Formula (III), R ¹¹ represents a substituent, R ¹² represents a substituent represented by the following General Formula (III-1), n1 represents an integer of 0 to 4, and n1 is 2 or more. In this case, the plurality of R ¹¹ may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, the plurality of R ¹² are the same or different from each other. (However, the sum of n1 and n2 is an integer of 1 to 5.)
Formula (III-1)

(In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring, and R ¹³ and R ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula: Represents a group represented by (III-2), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ¹ represents a substituted or unsubstituted monovalent aromatic ring, and n3 represents Represents an integer of 0 to 10, and when n3 is 2 or more, the plurality of R ¹⁵ and X ¹ may be the same or different from each other.
Formula (III-2)

(In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ² is a substituted or unsubstituted monovalent group. N5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and X ² may be the same or different from each other. May be.)
[2]
Furthermore, 0.5-1.9 mass parts of compounds represented by the following general formula (IV) are contained with respect to 100 parts by mass of the compound represented by the general formula (III), according to [1]. Polarizing plate protective film.
Formula (IV)

(In the general formula (IV), R ²⁰ represents a substituted or unsubstituted alkyl group having 3 to ²⁰ carbon atoms, or a substituted or unsubstituted alkenyl group, and R ²¹ and R ²² are each independently a hydrogen atom or carbon. Represents a substituted or unsubstituted alkyl group having 1 to 6 atoms or a substituted or unsubstituted alkenyl group, and R ²¹ and R ²² may be bonded to each other to form a cyclic structure, where X is a single bond or a carbonyl group; Represents.)
[3]
The polarizing plate protective film according to [1] or [2], wherein the organic acid represented by the general formula (3) is a carboxylic acid derivative represented by the following general formula (3 ′).
General formula (3 ')

(In the general formula (3 ′), s and t are independently 1, 2 or 3, and R ⁴ is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, It represents an alkylsulfonyl group, an arylsulfonyl group, or a heterocyclic group, and may further have a substituent, provided that R ⁴ includes R ³ in the general formula (3).
[4]
The polarizing plate protective film according to [1] or [2], wherein the general formula (III-1) is represented by the following general formula (III-1-1).
Formula (III-1-1)

(In the general formula ^(III-1-1), the definition of R ^13, R ^{15, X 1} is Formula (III-1) in a ^{R 13, R 15, X 1} and synonymous, n3 is 0 Represents an integer of 5.)
[5]
The polarizing plate protective film according to [1], [2], or [4], wherein the compound represented by the general formula (III) contains 0.05 to 0.50 ppm of nickel on a mass basis.
[6]
The polarizing plate protective film according to any one of [1] to [5], wherein the (meth) acrylic resin has a mass average molecular weight of 1,000 to 2,000,000.
[7]
The polarizing plate protective film according to any one of [1] to [6], wherein the film thickness is 20 μm to 80 μm.
[8]
A polarizing plate comprising at least one polarizing plate protective film according to any one of [1] to [7].
[9]
A liquid crystal display device comprising at least one polarizing plate according to [8].

  According to the present invention, there are provided a polarizing plate protective film that is less colored (yellowing) and excellent in polarizing plate durability even in a high temperature and high humidity environment, a polarizing plate including the polarizing plate protective film, and a liquid crystal display device. Provided.

It is an example which shows the example of the liquid crystal display device of this invention.

  Hereinafter, although the form for implementing this invention is demonstrated in detail, this invention is not limited to these. In the present specification, when a numerical value represents a physical property value, a characteristic value, etc., the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”. . In the present specification, the description “(meth) acrylic resin” means “at least one of acrylic resin and methacrylic resin”. The same applies to “(meth) acrylate”, “(meth) acryloyl” and the like.

[Polarizing plate protective film]
The polarizing plate protective film of the present invention is a polymer containing a (meth) acrylic resin, a compound represented by the following general formula (1), a repeating unit derived from a monomer represented by the following general formula (2), A polarizing plate protective film comprising a compound represented by the following general formula (3) and at least one selected from a compound represented by the following general formula (III), the (meth) acrylic resin 100: The compound represented by the following general formula (1), the polymer containing the repeating unit derived from the monomer represented by the following general formula (2), and the compound represented by the following general formula (3) with respect to parts by mass And a polarizing plate protective film containing 1 to 20 parts by mass of at least one selected from the compounds represented by the following general formula (III).
General formula (1)

In general formula (1), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aromatic group. R ⁶ , R ⁷ and R ⁸ may each have a substituent.
General formula (2)

In general formula (2), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ² represents a substituent. (A) represents an atomic group necessary for forming a 5- or 6-membered ring. n represents an integer of 0 to 4.
General formula (3)
X ³ -L- (R ³ ) _m
In General Formula (3), X ³ represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, R ³ represents a hydrogen atom, and has 6 to 30 carbon atoms. An alkyl group, an alkenyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heterocyclic group having 6 to 30 ring members, and further having a substituent. Also good. m is 1 when L is a single bond, and m is (valence of L-1) when L is a divalent or higher linking group.
Formula (III)

In General Formula (III), R ¹¹ represents a substituent, R ¹² represents a substituent represented by the following General Formula (III-1), n1 represents an integer of 0 to 4, and n1 is 2 or more. And a plurality of R ¹¹ may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, a plurality of R ¹² may be the same or different from each other. Also good. However, the sum total of n1 and n2 is an integer of 1-5.
Formula (III-1)

In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring, and R ¹³ and R ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula ( III-2), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ¹ represents a substituted or unsubstituted monovalent aromatic ring, and n3 represents 0. Represents an integer of -10, and when n3 is 2 or more, the plurality of R ¹⁵ and X ¹ may be the same as or different from each other.
Formula (III-2)

In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ² is a substituted or unsubstituted monovalent group. Represents an aromatic ring, n5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and X ² may be the same or different Good.

<(Meth) acrylic resin>
The polarizer protective film of the present invention contains a (meth) acrylic resin.
The polarizer protective film of the present invention preferably contains a (meth) acrylic resin as a main component. Here, a main component refers to a component with the largest containing mass ratio among the components contained in a polarizer protective film. The polarizer protective film of the present invention preferably contains 10% to 100% by weight of (meth) acrylic resin, more preferably 20% to 100% by weight, and more preferably 30% to 100%. More preferably, it is contained by mass% or less.

The (meth) acrylic resin is obtained by polymerizing a (meth) acrylic monomer, but may contain a structural unit obtained from a monomer other than the (meth) acrylic monomer. As the (meth) acrylic resin in the present invention, those obtained by polymerizing a monomer composition containing an ultraviolet absorbing monomer and a (meth) acrylic monomer are preferable.
As an example of the ultraviolet absorbing monomer, a benzophenone ultraviolet absorbing monomer and a benzotriazole ultraviolet absorbing monomer are preferable, and a benzotriazole ultraviolet absorbing monomer is more preferable.
Only one type of ultraviolet absorbing monomer may be used, or two or more types may be used in combination.

  Any appropriate (meth) acrylic monomer may be employed as the (meth) acrylic monomer within a range not impairing the effects of the present invention. For example, (meth) acrylic acid and (meth) acrylic acid ester are mentioned. Preferable examples include (meth) acrylic acid having a cyclic structure and alkyl esters having 1 to 6 carbon atoms of (meth) acrylic acid, and only one (meth) acrylic monomer may be used. Two or more kinds may be used in combination. More preferable examples include (meth) acrylic acid, methyl methacrylate and copolymers thereof having a cyclic structure as shown below.

  As the (meth) acrylic resin, a (meth) acrylic resin having a cyclic structure in the main chain is preferable in that it has high heat resistance, high transparency, and high mechanical strength. The (meth) acrylic resin having a cyclic structure in the main chain includes a (meth) acrylic resin having a lactone ring structure, a (meth) acrylic resin having a glutarimide ring structure, and a glutaric anhydride ring structure (meta ) Acrylic resin, (meth) acrylic resin having maleic anhydride ring structure, (meth) acrylic resin having maleimide ring structure is more preferred, (meth) acrylic resin having lactone ring structure, glutarimide ring structure (Meth) acrylic resins having a lactone ring structure are more preferred, and (meth) acrylic resins having a lactone ring structure are particularly preferred.

  Examples of the (meth) acrylic resin having a lactone ring structure include JP 2000-230016, JP 2001-151814, JP 2002-120326, JP 2002-254544, and JP 2005. No. 146084, JP-A-2006-171464, and the like, and the above UV-absorbing monomer is further contained in the monomer composition when producing a (meth) acrylic resin having a lactone ring structure A (meth) acrylic resin produced from the monomer composition is preferred.

  Examples of the (meth) acrylic resin having a glutarimide ring structure include International Publication No. 05/054311, International Publication No. 05/108438, Japanese Unexamined Patent Application Publication No. 2010-261625, Japanese Unexamined Patent Application Publication No. 2010-270162, Japanese Unexamined Patent Application Publication No. 2010. A (meth) acrylic resin having a glutarimide ring structure described in JP-A-284840, JP-A 2011-88440, JP-A 2011-138119, JP-A 2011-245624 and the like is preferable.

  Known (meth) acrylic resins having a glutaric anhydride ring structure, (meth) acrylic resins having a maleic anhydride ring structure, and (meth) acrylic resins having a maleimide ring structure can be used.

  The mass average molecular weight (Mw) of the (meth) acrylic resin in the present invention is preferably from 1,000 to 2,000,000, more preferably from 5,000 to 1,000,000, and even more preferably from 10,000 to 1,000,000.

[Compound represented by general formula (1)]
The compound represented by the general formula (1) will be described.
General formula (1)

In general formula (1), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aromatic group. R ⁶ , R ⁷ and R ⁸ may each have a substituent.

R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or 6 to 20 carbon atoms. It is preferable that it is an aromatic group.

R ⁶ is more preferably an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, and an alkyl group having 1 to 12 carbon atoms or a carbon number. It is more preferably a cycloalkyl group having 3 to 12 carbon atoms or an aromatic group having 6 to 18 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aromatic group having 6 to 12 carbon atoms. It is more preferably a group, more preferably a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group, a benzyl group or a phenyl group, and most preferably a methyl group, an isopropyl group or a phenyl group.

R ⁷ and R ⁸ are each independently more preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. More preferably, they are an atom, a C1-C12 alkyl group, a C3-C12 cycloalkyl group, or a C6-C12 aryl group, a hydrogen atom, a C1-C8 alkyl group, and a carbon number More preferably, it is a 3-6 cycloalkyl group or a phenyl group, particularly preferably a hydrogen atom, a methyl group, an ethyl group, a cyclohexyl group, a benzyl group or a phenyl group, a methyl group, a benzyl group or a phenyl group. Most preferably.

R ⁶ may further have a substituent. The substituent that R ⁶ may have is not particularly limited as long as it does not contradict the gist of the present invention, but is preferably a halogen atom, an alkyl group, or an aromatic group, and preferably a halogen atom, a carbon number It is more preferably an alkyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, and particularly preferably a chlorine atom, a methyl group, or a phenyl group. In particular, when R ⁶ is an alkyl group having 1 to 20 carbon atoms, it preferably has an aromatic group as a substituent, more preferably an aromatic group having 6 to 12 carbon atoms, and a phenyl group. Is particularly preferred. In particular, when R ⁶ is an aromatic group having 6 to 20 carbon atoms, it preferably has a halogen atom or an alkyl group having 1 to 20 carbon atoms as a substituent, and a halogen atom or an alkyl group having 1 to 6 carbon atoms. It is more preferable to have a group, and it is particularly preferable to have a chlorine atom or a methyl group.

R ⁷ and R ⁸ may further have a substituent. The substituent that R ⁷ and R ⁸ may have is not particularly limited as long as it does not contradict the gist of the present invention, but is preferably an aromatic group having 6 to 12 carbon atoms, and may be a phenyl group. More preferably.

  Although the specific example of a compound represented by General formula (1) below is illustrated, this invention is not limited to the following.

(how to get)
The compound represented by the general formula (1) may be obtained commercially or synthesized by a known method.

It is known that the compound represented by the general formula (1) can be synthesized using a method for synthesizing barbituric acid in which a urea derivative and a malonic acid derivative are condensed. For barbituric acid having two substituents on the nitrogen atom, heat N, N 'disubstituted urea and malonic acid chloride or a combination of malonic acid and an activator such as acetic anhydride. For example, Journal of the American Chemical Society, 61, 1015 (1939), Journal of Medicinal Chemistry, 54, 2409 (2011), Tetrahedron Letter, 29, 80. 1999), the method described in WO2007 / 150011 and the like can be preferably used.
In addition, the malonic acid used for the condensation may be unsubstituted or substituted, and if malonic acid having a substituent corresponding to R ⁶ is used, a barbituric acid is constructed to construct the general formula (1) Can be synthesized. Further, when the unsubstituted malonic acid and the urea derivative are condensed, a 5-position unsubstituted barbituric acid is obtained. By modifying this, the compound represented by the general formula (1) may be synthesized. .
In addition, the synthesis method of the compound represented by General formula (1) is not limited to the above.

When the polarizing plate protective film of the present invention contains the compound represented by the general formula (1), the content of the compound represented by the general formula (1) is 1 to 100 parts by mass of the acrylic resin. 20 parts by mass, preferably 1 to 10 parts by mass, more preferably 2 to 7 parts by mass, and still more preferably 3 to 6 parts by mass.
Moreover, also when using together 2 or more types of compounds represented by General formula (1), it is preferable that the sum total is the said range.
By setting it as the above content, the polarizing plate protective film excellent in polarizing plate durability and excellent in transparency can be obtained.

  When the polarizing plate protective film of the present invention contains the compound represented by the general formula (1), it is represented by the following general formula (A) from the viewpoint of suppressing decomposition of the compound represented by the general formula (1). The reductone may be further contained. When containing reductones, it is preferable to contain in the range of 0.1-20 mass parts with respect to 100 mass parts of compounds represented by the said General formula (1), 0.1-10 mass parts It is more preferable to contain within the range.

In general formula (A), R ^A1 and R ^A2 each independently represent a hydroxy group, an amino group, an acylamino group, an alkylsulfonylamino group, an arylsulfonylamino group, an alkoxycarbonylamino group, a mercapto group, or an alkylthio group. X is composed of a carbon atom, an oxygen atom and / or a nitrogen atom, and represents a nonmetallic atom group constituting a 5- to 6-membered ring together with —C (═O) —C (R ^A1 ) ═C (R ^A2 ) —. .

R ^A1 and R ^A2 are preferably a hydroxy group, an amino group, an alkylsulfonylamino group or an arylsulfonylamino group, more preferably a hydroxy group or an amino group, and even more preferably a hydroxy group.

X has at least one —O— bond, and —C (R ^A3 ) (R ^A4 ) —, —C (R ^A5 ) ═, —C (═O) —, —N (Ra) — and — It is preferable to be configured by combining one or more of N =. Here, R ^{A3 to} R ^A5 and Ra are each independently a hydrogen atom, an alkyl group which may have a substituent having 1 to 10 carbon atoms, an aryl group having 6 to 15 carbon atoms which may have a substituent, A hydroxy group or a carboxyl group is preferred.

The 5- to 6-membered ring formed through X includes, for example, a cyclopentenone ring (2-cyclopenten-1-one ring; the formed compound becomes reductic acid), a furanone ring [2 (5H) -Furanone ring], dihydropyranone ring [3,4-dihydro-2H-pyran-4-one ring (2,3-dihydro-4H-pyrone ring), 3,6-dihydro-2H-pyran-2-one Ring, 3,6-dihydro-2H-pyran-6-one ring (5,6-dihydro-2-pyrone ring)], 3,4-dihydro-2H-pyrone ring, cyclopentenone ring, furanone A ring and a dihydropyrone ring are preferable, a furanone ring and a dihydropyrone ring are more preferable, and a furanone ring is particularly preferable.
These rings may be condensed, and the condensed ring may be either a saturated ring or an unsaturated ring.

  Of the reductones represented by the general formula (A), a compound represented by the following general formula (A1) is preferable, and a compound represented by the following general formula (A2) is particularly preferable.

In general formula (A1), R ^a1 represents a hydrogen atom, an alkyl group, an aryl group, or a heterocyclic group, and they may have a substituent.
R ^a1 is preferably an alkyl group which may have a substituent, more preferably —CH (OR ^a3 ) CH ₂ OR ^a2 , and in this case, a compound represented by the above general formula (A2).

In general formula (A2), R ^a2 and R ^a3 each independently represent a hydrogen atom, an alkyl group, an acyl group, or an alkoxycarbonyl group, and R ^a2 and R ^a3 may be bonded to each other to form a ring, The ring to be formed is preferably a 1,3-dioxolane ring, and this ring may further have a substituent. A compound having a dioxolane ring can be synthesized by acetalization or ketalization by reaction of ascorbic acid with ketones or aldehydes, and raw material ketones or aldehydes can be used without particular limitation.

One particularly preferred combination of substituents is a compound in which R ^a2 is an acyl group and R ^a3 is a hydrogen atom, and the acyl group may be either an aliphatic acyl group or an aromatic acyl group. In such a case, the number of carbon atoms is preferably 2 to 30, more preferably 4 to 24, and still more preferably 8 to 18. In the case of an aromatic acyl group, the carbon number is preferably 7-24, more preferably 7-22, and still more preferably 7-18. Preferred acyl groups include butanoyl, hexanoyl, 2-ethylhexanoyl, decanoyl, lauroyl, myristoyl, palmitoyl, stearoyl, palmitoleyl, myristolyl, oleoyl, benzoyl, 4-methylbenzoyl and 2-methylbenzoyl. it can.

[Monomer represented by general formula (2)]
The monomer represented by the general formula (2) will be described.
General formula (2)

In general formula (2), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ² represents a substituent. (A) represents an atomic group necessary for forming a 5- or 6-membered ring. n represents an integer of 0 to 4.

・ R ¹
In the formula, R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ¹ is not particularly limited, but is preferably a hydrogen atom, a methyl group, or an ethyl group.

・ R ²
R ² represents a substituent, and the substituent is preferably an aliphatic group or an aromatic group.
R ² is not particularly limited, but the aliphatic group is preferably an alkyl group, an alkenyl group, an alkynyl group or a cycloalkyl group, more preferably an alkyl group having 1 to 6 carbon atoms, a methyl group, an ethyl group or a propyl group. A butyl group is preferable, and a methyl group and a t-butyl group are particularly preferable. As the aromatic group, a phenyl group, a naphthyl group, and a biphenyl group are preferable, and a phenyl group is particularly preferable.

・ N
n represents an integer of 0 to 4, preferably 0 to 2, and more preferably 0 to 1. In addition, when n is 0, the substituent R ² does not exist, but in the chemical formula, this means that a hydrogen atom may be present here. In the other chemical formulas of the present specification, the chemical structure should be interpreted consistently as described above.

・ (A)
(A) represents an atomic group necessary for forming a 5- or 6-membered ring, and is preferably a 5- or 6-membered aromatic ring. In this specification, the aromatic ring is a concept including an aromatic ring not containing a hetero atom and a saturated / unsaturated hetero ring having a hetero atom.

  In the present invention, the repeating unit derived from the monomer represented by the general formula (2) has the following general formulas (2-1), (2-2), (2-3), (2-4), Or it is preferable to be represented by (2-5).

In formula, R < ¹⁰ > -R < ¹⁵ >, R < ¹⁸ > -R < ¹⁹ > represents a substituent each independently. n1, n2, n5, n8, and n10 each independently represents an integer of 0 to 4. n3 and n9 each independently represent 0-2. n4 represents 0 or 1 each independently. R ^1A represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms.

^{· R 10 ~R 15, R 18} ~R 19
In the formula, R ^{10 to} R ¹⁵ and R ^{18 to} R ¹⁹ each independently represent a substituent. Although a substituent is not specifically limited, The following substituent T is mentioned, The preferable range is also synonymous.

・ N1-n5, n8-n10
n1, n2, n5, n8 and n10 each independently represents an integer of 0 to 4, preferably 0 to 2. n3 represents 0-2, and 0-1 is preferable. n4 and n9 each independently represents 0 or 1, and 0 is preferred.

・ R ^1A
R ^1A represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ^1A is not particularly limited, but is preferably a hydrogen atom, a methyl group, or an ethyl group.

  In the present invention, the polymer containing a repeating unit derived from the monomer represented by the general formula (2) is a coumarone resin containing three components represented by the following general formula (P-1) as a repeating unit. Preferably there is. Here, the coumarone resin is a generic name for copolymers having any specific copolymerization ratio synthesized from petroleum residues, as well as copolymers comprising any or all of coumarone-indene-styrene. Therefore, the copolymer represented by the following formula (P-1) is included in the category of coumarone resin.

In the formula, R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a substituent. x, y, z represents a mole fraction (%) with respect to all repeating units contained in the polymer, x represents 1 to 40, y represents 5 to 95, and z represents 1 to 70. m1 and m2 each independently represents an integer of 0 to 4. m3 represents an integer of 0-2. m4 represents an integer of 0 to 5. R ¹⁰¹ , R ¹⁰² and R ¹⁰³ each independently represent a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms.

・ R ^{21 to} R ²⁴
R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a substituent. Although a substituent is not specifically limited, The following substituent T is mentioned, The preferable range is also synonymous.

・ R ^{101 to} R ¹⁰³
R ^{101 to} R ¹⁰³ represent a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ^{101 to} R ¹⁰³ are preferably a hydrogen atom, a methyl group, or an ethyl group.

X, y, z
x, y, z represents a mole fraction (%) with respect to all repeating units contained in the polymer.
x represents 1-40, 1-30 are preferable and 1-20 are more preferable. y represents 5-95, 10-90 are preferable and 30-90 are more preferable. z represents 1-70, 1-60 are preferable and 1-50 are more preferable. x + y + z may not be 100, but when it is less than 100, it means that there are other copolymerization components. Other copolymer components include vinyl toluene, isopropenyl toluene, α-methyl styrene, alkylindene, dicyclopentadiene, and the like. 0-30 are preferable and, as for copolymerization ratio (%) t of another copolymerization component, 0-20 are more preferable.

・ M1-m4
m1 and m2 represent an integer of 0 to 4, and 0 to 2 are preferable. m3 represents an integer of 0 to 2, and 0 is preferable. m4 represents an integer of 0 to 5, preferably 0 to 3, and more preferably 0 to 1.

  The terminal group of the polymer containing the repeating unit derived from the monomer represented by the general formula (2) may be any one, and typically, the polymerization is terminated by adding hydrogen to the vinyl group. It is a structured.

  Although the specific example of the polymer containing the repeating unit derived from the monomer represented by General formula (2) below is shown, this invention is limited to this and is not interpreted. In addition, the following structural formula has shown the chemical structure of the repeating unit of the main component, and its structural ratio, and it is as above-mentioned that the other component may be contained. Moreover, as a specific example of the commercially available coumarone resin, “V-120S” manufactured by Nippon Paint Chemical Co., Ltd. can be mentioned.

(Mass average molecular weight)
The mass average molecular weight of the polymer containing a repeating unit derived from the monomer represented by the general formula (2) is preferably 200 to 10,000, more preferably 300 to 8,000, and 400 to 4 Is particularly preferred. When the molecular weight is equal to or higher than the lower limit, an effect of effectively suppressing the moisture permeability and moisture content of the film can be expected, and when it is equal to or lower than the upper limit, compatibility with the (meth) acrylic resin can be expected to be preferable. .
Unless otherwise specified, the molecular weight and the degree of dispersion are values measured using a GPC (gel filtration chromatography) method, and the molecular weight is a weight average molecular weight in terms of polystyrene. The gel packed in the column used in the GPC method is preferably a gel having an aromatic compound as a repeating unit, and examples thereof include a gel made of a styrene-divinylbenzene copolymer. It is preferable to use 2 to 6 columns connected together. Examples of the solvent used include ether solvents such as tetrahydrofuran and amide solvents such as N-methylpyrrolidinone. The measurement is preferably performed at a solvent flow rate in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, the apparatus is not loaded and the measurement can be performed more efficiently. The measurement temperature is preferably 10 to 50 ° C, most preferably 20 to 40 ° C. Note that the column and carrier to be used can be appropriately selected according to the physical properties of the polymer compound that is symmetrical to the measurement.

  In this specification, a polymer or a polymer includes not only a polymer that is a general polymer compound in which a large number of monomers are polymerized, but also an oligomer that is a compound having a molecular weight of about several hundreds in which several monomers are polymerized. Means. The term “polymer” or “polymer” means a copolymer or copolymer unless otherwise specified.

  In the present specification, when the term “compound” is added to the end or indicated by a specific name or chemical formula, it is used in the meaning including its salt, complex, and ion in addition to the compound itself. Moreover, it is the meaning including the derivative modified with the predetermined form in the range with the desired effect. Furthermore, in the present specification, when a specific group of atoms is referred to with the word “group” at the end of a substituent, this means that the group may have an arbitrary substituent. This is also synonymous for compounds that do not specify substitution / non-substitution. Preferred substituents include the following substituent T.

Examples of the substituent T include the following.
An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, for example, methyl group, ethyl group, isopropyl group, t-butyl group, pentyl group, heptyl group, 1-ethylpentyl group, benzyl group, 2-ethoxyethyl group) 1-carboxymethyl group, etc.), alkenyl group (preferably alkenyl group having 2-20 carbon atoms, such as vinyl group, allyl group, oleyl group, etc.), alkynyl group (preferably alkynyl having 2-20 carbon atoms). Group such as ethynyl group, butadiynyl group, phenylethynyl group, etc., cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl group, cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group) Etc.), an aryl group (preferably an aryl group having 6 to 26 carbon atoms, such as phenyl Group, 1-naphthyl group, 4-methoxyphenyl group, 2-chlorophenyl group, 3-methylphenyl group, etc.), heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, such as 2-pyridyl group, 4-pyridyl group, 2-imidazolyl group, 2-benzimidazolyl group, 2-thiazolyl group, 2-oxazolyl group, etc.), alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy group, ethoxy group, Isopropyloxy group, benzyloxy group, etc.), aryloxy group (preferably an aryloxy group having 6 to 26 carbon atoms, such as phenoxy group, 1-naphthyloxy group, 3-methylphenoxy group, 4-methoxyphenoxy group, etc. ), An alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, such as Carbonyl group, 2-ethylhexyloxycarbonyl group, etc.), amino group (preferably an amino group having 0 to 20 carbon atoms, such as amino group, N, N-dimethylamino group, N, N-diethylamino group, N-ethyl group) Amino groups, anilino groups, etc.), sulfonamido groups (preferably sulfonamido groups having 0 to 20 carbon atoms such as N, N-dimethylsulfonamido group, N-phenylsulfonamido group, etc.), acyloxy groups (preferably An acyloxy group having 1 to 20 carbon atoms, such as an acetyloxy group and a benzoyloxy group, a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, such as an N, N-dimethylcarbamoyl group, N-phenyl); A carbamoyl group), an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms, for example Acetylamino group, benzoylamino group, etc.), cyano group, or halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), more preferably alkyl group, alkenyl group, aryl group, heterocyclic ring Group, alkoxy group, aryloxy group, alkoxycarbonyl group, amino group, acylamino group, cyano group or halogen atom, particularly preferably alkyl group, alkenyl group, heterocyclic group, alkoxy group, alkoxycarbonyl group, amino group, An acylamino group or a cyano group is mentioned.

When the polarizing plate protective film of the present invention contains a polymer containing a repeating unit derived from the monomer represented by the general formula (2), a weight containing a repeating unit derived from the monomer represented by the general formula (2) is used. The content of the coalescence is 1 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin, preferably 1 to 10 parts by mass, more preferably 2 to 7 parts by mass, More preferably, it is 3-6 mass parts.
By setting it as the above content, the polarizing plate protective film excellent in polarizing plate durability and excellent in transparency can be obtained.

[Compound represented by formula (3)]
The compound represented by the general formula (3) will be described.
General formula (3)
X ³ -L- (R ³ ) m
In General Formula (3), X ³ represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, R ³ represents a hydrogen atom, and has 6 to 30 carbon atoms. An alkyl group, an alkenyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heterocyclic group having 6 to 30 ring members, and further having a substituent. Also good. m is 1 when L is a single bond, and m is (valence of L-1) when L is a divalent or higher linking group.

In the general formula (3), X ³ represents an acid having an acid dissociation constant of 5.5 or less, preferably a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, a sulfonic imide group, or an ascorbic acid group. A sulfonic acid group is more preferable, and a carboxyl group is most preferable. In the case where X ³ represents ascorbic acid derivative, of the hydrogen atoms of ascorbic acid, 5-position, it is preferable that a hydrogen atom of the 6-position position is linked to a L out.
In this specification, as an acid dissociation constant, the value described in Chemical Handbook, published by Maruzen Co., Ltd. is adopted.

In General Formula (3), R ³ is a hydrogen atom, an alkyl group having 6 to 30 carbon atoms (which may have a substituent or a cycloalkyl group), an alkenyl group having 6 to 30 carbon atoms ( May have a substituent), an alkynyl group having 6 to 30 carbon atoms (which may have a substituent), an aryl group having 6 to 30 carbon atoms (which may have a substituent), and the number of ring members It represents a 6-30 heterocyclic group (which may have a substituent). As a substituent, a halogen atom, an alkyl group (preferably having 1 to 10 carbon atoms, more preferably 1 to 6), an aryl group, a heterocyclic group, an alkoxyl group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a hydroxyl group Group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamide group, sulfolyl group, carboxyl group and the like.
R ³ is more preferably an aryl group having 6 to 24 carbon atoms, a heterocyclic group having 6 to 24 ring members, an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an alkynyl group, and most preferably 6 to 6 carbon atoms. 20 aryl groups, heterocyclic groups having 6 to 20 ring members, linear alkyl groups having 10 to 24 carbon atoms, and alkenyl groups.

L in the general formula (3) is preferably a single bond, a unit obtained from the following group, or a divalent or higher linking group obtained by combining these units.
Units: —O—, —CO—, —N (R ³¹ ) — (wherein R ³¹ is an alkyl group having 1 to 5 carbon atoms), —CH═CH—, —CH (OH) —, —CH ₂ —, -SO ₂ -.
L in the general formula (3) is a single bond, an ester group-derived linking group (—COO—, —OCO—), or an amide group-derived linking group (—CON (R ³¹ ) —, —N (R ³¹ ). It is particularly preferred to have CO-) as a partial structure.
In addition, L may further have a substituent, and the substituent is not particularly limited, and examples thereof include the substituent that R ³ may have. Alternatively, an alkyl group (more preferably an alkyl group substituted with a carboxyl group) is preferable.
In addition, R ³¹ may further have a substituent, and the substituent is not particularly limited, and examples thereof may include a substituent that R ³ may have. preferable.
Among these, L is more preferably a linking group containing a group derived from glycerin or a group derived from iminodiacetic acid (—N (CH ₂ COOH) (CH ₂ COOH)).
Specifically, L preferably has the following structure. However, in the following, p, q, and r each represents an integer of 1 to 40, preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Further, q is more preferably 2-4.

_{L1: - (CH 2) p} -CO-O- (CH 2) q -O-;
_{L2: - (CH 2) p} -CO-O- (CH 2) q - (CH (OH)) - (CH 2) r -O-;
_{L3: - (CH 2) p} -CO-O- (CH 2) q - (CH (OCO-R 30)) - (CH 2) r -O-;
_{L4: - (CH 2) p} -CO-O- (CH 2) q - (CH (OH)) - (CH 2) r -O-CO-;
_{- (CH 2) p -CO-} O- (CH 2) q - (CH (OCO-R 30)) - (CH 2) r -O-CO-;
_{L5 :-( CH 2) p -N (} CH 2 COOH) -;
_{L6: - (CH 2) p} -N (CH 2 COOH) - (CH 2) q -;
_{L7: - (CH 2) p} -N (CH 2 COOH) - (CH 2) q -O-;
_{L8: - (CH 2) p} -N (CH 2 COOH) - (CH 2) q -CONH-;
_{L9: - (CH 2) p} -N (CH 2 COOH) - (CH 2) q -CONH- (CH 2) r -;
_{L10: - (CH 2) p} -N (CH 2 COOH) -CO-;
_{L11: - (CH 2) p} -N (CH 2 COOH) -CO-CH (CH 2 COOH) -;
_{L12: - (CH 2) p} -N (CH 2 COOH) -SO 2 -.

Incidentally, R ³⁰ contained in the above specific example of L is the same as defined in the R ³ in the general formula (3). _{That, - (CH 2) p -CO} -O- (CH 2) q - (CH (OCO-R 3)) - (CH 2) R 3 in the connection group that r -O- is for convenience described in the interior of the L The linking group L means a portion excluding R ³⁰ . That is, in this case, L is trivalent. When represented by the general formula (3), X ³ -L- (R ³ ) ₂ , wherein L is — (CH ₂ ) _p —CO—O— (CH ₂ ) _q — (CH (OCO —)) — ( Represents a CH ₂ ) _r —O—], that is, the linking group L at this time is a trivalent linking group.
The L and the X ³ are preferably bonded by an ester bond or an amide bond, and more preferably bonded by an ester bond. Further, it is preferable that the X ³ does not have an ester bond or an amide bond.
L and R ³ are preferably bonded by an ester bond, an ether bond or an amide bond, more preferably an ester bond or an amide bond, and particularly preferably an ester bond. . R ³ preferably has no ester bond, ether bond or amide bond.

Preferred specific examples of the organic acid represented by the general formula (3) of the present invention are listed below.
"fatty acid"
Myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinolenic acid, undecanoic acid.
《Alkyl sulfate》
Myristyl sulfate, cetyl sulfate, oleyl sulfate.
《Alkylbenzene sulfonic acid》
Dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid.
《Alkyl naphthalene sulfonic acid》
Sesquibutyl naphthalene sulfonic acid, diisobutyl naphthalene sulfonic acid.
《Dialkylsulfosuccinic acid》
Dioctylsulfosuccinic acid, dihexylsulfosuccinic acid, dicyclohexylsuccinic acid, diamylsulfosuccinic acid, ditridecylcyclosuccinic acid.

<< Polyvalent carboxylic acid represented by formula (3 ') >>
The organic acid represented by the general formula (3) is preferably a polyvalent carboxylic acid represented by the following general formula (3 ′).
General formula (3 ')

In the general formula (3 ′), s and t are independently 1, 2 or 3, and R ⁴ is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, an alkyl Represents a sulfonyl group, an arylsulfonyl group, or a heterocyclic group, and may further have a substituent. However, R ⁴ includes R ³ in the general formula (3).

  More preferably, s and t are each independently 1 or 2, more preferably 1.

R ⁴ is more preferably an alkyl group having 1 to 30 carbon atoms (which may have a substituent or a cycloalkyl group) or an arylsulfonyl group having 6 to 30 carbon atoms (having a substituent). Or an acyl group (which may have a substituent), more preferably an alkyl group having 1 to 30 carbon atoms, and still more preferably an alkyl group having 1 to 24 carbon atoms (substituted). Group, which may have a group), particularly preferably an alkyl group having 1 to 20 carbon atoms.
Examples of the substituent of the group represented by R ⁴ include an alkyl group, a halogen atom, an aryl group, a heterocyclic group, an alkoxyl group, an aryloxy group, an alkylthio group, an arylthio group, an acyl group, a hydroxyl group, an acyloxy group, an amino group, and an alkoxy group. Examples include carbonyl group, acylamino group, oxycarbonyl group, carbamoyl group, sulfonyl group, sulfamoyl group, sulfonamide group, carboxyl group and the like. As the substituent of the group represented by R ⁴ , an alkyl group, an acyl group, an aryl group, and a carbamoyl group are more preferable, and an aryl group and a carbamoyl group are more preferable.
The substituent of the group represented by R ⁴ may further have a substituent, and the preferred range of the substituent is the same as the preferred range of the substituent of the group represented by R ⁴ .
R ⁴ is most preferably an alkyl group having 1 to 24 carbon atoms having an aryl group as a substituent or an alkyl group having 1 to 24 carbon atoms having a carbamoyl group as a substituent, and the carbamoyl group is It is preferably substituted with an aryl group. Further, the aryl group is preferably substituted with an alkyl group having 1 to 10 carbon atoms, and most preferably substituted with an alkyl group having 1 to 8 carbon atoms.

  Specific examples of the carboxylic acid derivative represented by the general formula (3 ') include, for example, N- (2,6-diethylphenylcarbamoylmethyl) iminodiacetic acid represented by the formula (31);

N-benzyliminodiacetic acid represented by the formula (32);

Formula (33)-(40);

Lauraminodiacetic acid represented by the formula (41);

Formulas (42) to (50);

The compound represented by these is mentioned.

《Partial derivative of polyvalent organic acid》
The compound represented by the general formula (3) is preferably a partial derivative of a polyvalent organic acid. In the present specification, a partial derivative of a polyvalent organic acid has a structure in which one molecule of a fatty acid and one polyvalent organic acid are ester-bonded to one molecule of a polyhydric alcohol. A compound having at least one acidic group. In the present specification, the fatty acid means an aliphatic monocarboxylic acid. That is, the fatty acids in the present specification are not limited to so-called higher fatty acids, and also include lower fatty acids having 12 or less carbon atoms such as acetic acid and propionic acid.
The partial derivative of the polyvalent organic acid is preferably a partial derivative of a polyvalent carboxylic acid. That is, the compound represented by the general formula (3) has a structure in which one molecule of a fatty acid and one molecule of a polyvalent carboxylic acid are ester-bonded to one molecule of a polyhydric alcohol, and is unsubstituted from the polyvalent carboxylic acid. It is preferable to have at least one carboxyl group. Although it does not specifically limit as polyvalent carboxylic acid used for the partial derivative of the said polyvalent carboxylic acid, For example, a succinic acid, a citric acid, tartaric acid, diacetyl tartaric acid, malic acid, and adipic acid are preferable.

  Examples of the polyhydric alcohol used in the partial derivative of the polyvalent organic acid include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane-1,3 , 5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol, glycerin and the like. Among them, glycerin is preferable, and the compound represented by the general formula (3) is preferably a so-called organic acid glyceride.

As a compound represented by the general formula (3), an organic acid glyceride (glycerin) in which an acidic group X ³ of an organic acid is bonded to a hydrophobic part R ¹ via a linking group L containing a group derived from glycerin. Fatty acid organic acid esters) are preferred. Here, the organic acid glyceride in the present specification means that one or two of the three hydroxyl groups of glycerol form an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups are It refers to a compound having an ester bond with a polyvalent organic acid and having an acidic group derived from the polyvalent organic acid.
Among these, organic acid monoglycerides or organic acid diglycerides are more preferable, and organic acid monoglycerides are more preferable. In this specification, the organic acid monoglyceride means that one of the three hydroxyl groups of glycerin forms an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups are an ester bond with a polyvalent organic acid. And a compound having a structure having an acidic group derived from the polyvalent organic acid. In this specification, the organic acid diglyceride means that two of the three hydroxyl groups of glycerin make an ester bond with a fatty acid, and the remaining one hydroxyl group makes an ester bond with a polyvalent organic acid. And a compound having a structure having an acidic group derived from the polyvalent organic acid.
Among the organic acid monoglycerides, one of the three hydroxyl groups of glycerin forms an ester bond with a fatty acid, one of the remaining hydroxyl groups is an unsubstituted hydroxyl group, and the remaining hydroxyl group 1 It is particularly preferred that the compound has an ester bond with the polyvalent organic acid and has a structure having an acidic group derived from the polyvalent organic acid. The hydroxyl group that is ester-bonded to the fatty acid of the organic acid monoglyceride is preferably an asymmetric position (so-called α-monoglyceride position), and the hydroxyl group that is ester-bonded to the polyvalent organic acid of the organic acid monoglyceride is the same. Are preferably asymmetric positions (positions of so-called α monoglycerides). That is, among the organic acid monoglycerides, a carbon atom directly bonded to a hydroxyl group having an unsubstituted hydroxyl group and ester-bonded to a fatty acid is directly connected to a hydroxyl group ester-bonded to a polyvalent organic acid. A compound having a structure in which a carbon atom is not adjacent is preferable.

  Among the organic acid monoglycerides, monoglycerides of polyvalent carboxylic acids are particularly preferable. The monoglyceride of the polyvalent carboxylic acid refers to an organic acid in which at least one of the polyvalent carboxylic acids has an unsubstituted carboxyl group and the other carboxyl groups are substituted with the monoglyceride. That is, a carboxyl group-containing organic acid monoglyceride in which one molecule of fatty acid and one molecule of polyvalent carboxylic acid are bonded to one molecule of glycerin is particularly preferable.

Although it does not specifically limit as said polyvalent carboxylic acid used for the monoglyceride of the said polyvalent carboxylic acid, For example, a succinic acid, a citric acid, tartaric acid, diacetyl tartaric acid, malic acid, and adipic acid are preferable.
The fatty acid used in the monoglyceride of the polyvalent carboxylic acid is not limited, but is preferably a saturated or unsaturated fatty acid having 8 to 22 carbon atoms, specifically, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid. Examples include acid, stearic acid, behenic acid, oleic acid and the like.

  The carboxyl group-containing organic acid monoglyceride that can be used in the production method of the present invention will be described in detail below.

The carboxyl group-containing organic acid monoglyceride that can be used in the present invention is generally an anhydride of a polyvalent organic acid according to the method described in JP-A-4-218597, JP-A-3823524, etc. And fatty acid monoglyceride.
The reaction is usually carried out under solvent-free conditions. For example, in the reaction of succinic anhydride and a fatty acid monoglyceride having 18 carbon atoms, the reaction is completed in about 90 minutes at a temperature of about 120 ° C. The organic acid monoglyceride thus obtained is usually a mixture containing an organic acid, unreacted monoglyceride, diglyceride, and other oligomers. In the present invention, such a mixture may be used as it is.
When it is desired to increase the purity of the carboxyl group-containing organic acid monoglyceride, the carboxyl group-containing organic acid monoglyceride in the mixture as described above may be purified by distillation or the like. Commercially available as distilled monoglyceride can be used. Commercially available products of the carboxyl group-containing organic acid monoglycerides include, for example, Poem K-37V (glycerine citrate oleate) manufactured by Riken Vitamin Co., Ltd., Step SS (glycerol stearate / palmitate succinate produced by Kao) ) Etc.

  When the polarizing plate protective film of this invention contains the compound represented by General formula (3), content of the compound represented by General formula (3) is 100 mass parts of (meth) acrylic-type resin. It is a ratio of 1 to 20 parts by mass, particularly preferably 1 to 10 parts by mass, and particularly preferably 1 to 5 parts by mass.

<Compound represented by formula (III)>
The polarizing plate protective film of this invention contains the compound represented by general formula (III) in the range of 1-20 mass parts with respect to 100 mass parts of (meth) acrylic-type resin.
Formula (III)

In General Formula (III), R ¹¹ represents a substituent, R ¹² represents a substituent represented by the following General Formula (III-1), n1 represents an integer of 0 to 4, and n1 is 2 or more. And a plurality of R ¹¹ may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, a plurality of R ¹² may be the same or different from each other. Also good. However, the sum total of n1 and n2 is an integer of 1-5.
Formula (III-1)

In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring, and R ¹³ and R ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula ( III-2), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ¹ represents a substituted or unsubstituted monovalent aromatic ring, and n3 represents 0. Represents an integer of -10, and when n3 is 2 or more, the plurality of R ¹⁵ and X ¹ may be the same as or different from each other.
Formula (III-2)

In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ² is a substituted or unsubstituted monovalent group. Represents an aromatic ring, n5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and X ² may be the same or different Good.

In the present invention, by adding the compound represented by the general formula (III) to the (meth) acrylic resin, moisture permeability can be lowered without deteriorating haze, and as a protective film for a polarizing plate. Suitable for use. Although it is not clear about the details that such an effect is obtained, it is considered that the compound represented by the general formula (III) has a strong interaction between a phenolic hydroxyl group and an aromatic ring. The (meth) acrylic resin has a higher stabilization energy by hydrogen bonding with the compound represented by the general formula (III) than by hydrogen bonding with water.
For this reason, when the (meth) acrylic resin containing the compound represented by the general formula (III) is formed into a film, the compound represented by the general formula (III) is the main chain of the (meth) acrylic resin. While it is easy to enter the vicinity, the amount of water molecules present in the vicinity of the main chain of the (meth) acrylic resin is reduced, and the interaction between water and the (meth) acrylic resin is weakened, so the hydrophobicity of the film Will increase. By increasing the hydrophobicity of the film, it is possible to suppress moisture permeation in the (meth) acrylic resin. For this reason, when a (meth) acrylic resin film containing a compound represented by the general formula (III) is used as a protective film for a polarizer, it is possible to suppress moisture from being transmitted into the polarizer, and to provide a high-temperature and high-humidity environment. It is thought that durability of the polarizing plate below is improved.
Moreover, it is thought that the production | generation of quinones by oxidation of phenol considered to be the cause of coloring (yellowing) can be suppressed by using the compound represented with general formula (IV) mentioned later.

In the general formula (III), R ¹¹ represents a substituent. Examples of the substituent are not particularly limited, and may be an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a pentyl group, a heptyl group, 1- Ethylpentyl group, benzyl group, 2-ethoxyethyl group, 1-carboxymethyl group and the like), alkenyl group (preferably an alkenyl group having 2 to 20 carbon atoms, such as vinyl group, allyl group, oleyl, etc.), alkynyl group (Preferably an alkynyl group having 2 to 20 carbon atoms, such as ethynyl group, butadiynyl group, phenylethynyl group, etc.), a cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as a cyclopropyl group, Cyclopentyl group, cyclohexyl group, 4-methylcyclohexyl group, etc.), aryl group (preferably having 6 carbon atoms) 26 aryl groups, for example, phenyl group, 1-naphthyl group, 4-methoxyphenyl group, 2-chlorophenyl group, 3-methylphenyl group, etc.), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms) For example, 2-pyridyl group, 4-pyridyl group, 2-imidazolyl group, 2-benzimidazolyl group, 2-thiazolyl group, 2-oxazolyl group, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, For example, methoxy group, ethoxy group, isopropyloxy group, benzyloxy group, etc.), aryloxy group (preferably aryloxy group having 6 to 26 carbon atoms, such as phenoxy group, 1-naphthyloxy group, 3-methylphenoxy group) Group, 4-methoxyphenoxy group, etc.), alkoxycarbonyl group (preferably an alkyl group having 2 to 20 carbon atoms). Xyloxycarbonyl group such as ethoxycarbonyl group and 2-ethylhexyloxycarbonyl group), amino group (preferably an amino group having 0 to 20 carbon atoms such as amino group, N, N-dimethylamino group, N, N -Diethylamino group, N-ethylamino group, anilino group, etc.), sulfonamide group (preferably a sulfonamide group having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide group, N-phenylsulfonamide group, etc. ), An acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms such as acetyloxy group, benzoyloxy group, etc.), a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms such as N, N- Dimethylcarbamoyl group, N-phenylcarbamoyl group, etc.), acylamino group (preferably carbon atom) Examples thereof include an acylamino group having 1 to 20 molecules, such as an acetylamino group and a benzoylamino group, a cyano group, a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom), and a hydroxyl group.
R ¹¹ is more preferably an alkyl group having 1 to 20 carbon atoms or a hydroxyl group, and more preferably an alkyl group having 1 to 3 carbon atoms or a hydroxyl group, from the viewpoint of compatibility with a (meth) acrylic resin. A hydroxyl group and a methyl group are particularly preferred.
R ¹¹ may have one or more substituents as substituents.

  In the said general formula (III), n1 represents the integer of 0-4 and 2-4 are preferable from a compatible viewpoint with (meth) acrylic-type resin.

  In the said general formula (III), n2 represents the integer of 1-5 and 1-3 are preferable from a compatible viewpoint with (meth) acrylic-type resin.

In the general formula (III), R ¹² represents a substituent represented by the general formula (III-1).

General formula (III-1) is demonstrated.
Formula (III-1)

In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring, and R ¹³ and R ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula ( III-2), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ¹ represents a substituted or unsubstituted monovalent aromatic ring, and n3 represents 0. Represents an integer of -10, and when n3 is 2 or more, the plurality of R ¹⁵ and X ¹ may be the same as or different from each other.

In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring. The aromatic ring may be a heterocyclic ring containing a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom.
Examples of A ^11, a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, a pyrene ring, a pyran ring, a dioxane ring, a dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine Ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring and the like. Further, other 6-membered rings or 5-membered rings may be condensed.
From the viewpoint of polarizing plate durability, A ¹¹ is preferably a benzene ring.
Examples of the substituent that A ¹¹ may have include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), an alkyl group, a hydroxyl group, and the like, and an alkyl group having 1 to 6 carbon atoms. Or a hydroxyl group is preferable.

In General Formula (III-1), R ¹³ and R ¹⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom A methyl group is more preferable.

In General Formula (III-1), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms. The alkylene group having 1 to 5 carbon atoms may have a substituent. From the viewpoint of compatibility with the (meth) acrylic resin, R ¹⁵ is preferably an alkylene group having 1 to 4 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. . Examples of the substituent that R ¹⁵ may have include an alkyl group having 1 to 5 carbon atoms (for example, a methyl group, an ethyl group, an isopropyl group, a t-butyl group), a halogen atom (for example, a fluorine atom, a chlorine atom, Bromine atom, iodine atom, etc.), hydroxyl group and the like.

In General Formula (III-1), X ¹ represents a substituted or unsubstituted monovalent aromatic ring (a monovalent group obtained by removing any one hydrogen atom from an aromatic ring). The aromatic ring may be a heterocyclic ring containing a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of X ¹ include benzene ring, indene ring, naphthalene ring, fluorene ring, phenanthrene ring, anthracene ring, biphenyl ring, pyrene ring, pyran ring, dioxane ring, dithiane ring, thiine ring, pyridine ring, piperidine ring, oxazine Ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring and the like. Further, other 6-membered rings or 5-membered rings may be condensed.
From the viewpoint of polarizing plate durability, X ¹ is preferably a benzene ring. The substituent which X ¹ may have is the same as the example given as the substituent for A ¹¹ .

In General Formula (III-1), n3 represents an integer of 0 to 10, and from the viewpoint of compatibility with (meth) acrylic resin, 0 to 4 is preferable, 0 to 3 is more preferable, and 0 to 2 is More preferably, 0-1 are especially preferable. Incidentally, n3 be a 2 or more integer, a plurality of - the groups represented by (R ^{15 -X 1)} may be the being the same or different, respectively, binds to A ^11, respectively.

The general formula (III-1) is preferably represented by the following general formula (III-1-1).
Formula (III-1-1)

In the general formula ^(III-1-1), the definition of R ^13, R ^{15, X 1} is Formula (III-1) in the same meaning as ^{R 13, R 15, X 1,} and preferred ranges are also the same is there.
n3 represents an integer of 0 to 5, and a preferred range is the same as n3 in the general formula (III-1).

The general formula (III-1) is preferably represented by the following general formula (III-1-2).
Formula (III-1-2)

  In general formula (III-1-2), the definition of n3 is synonymous with n3 in general formula (III-1-1), and the preferable range is also the same.

General formula (III-2) is demonstrated.
Formula (III-2)

In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ² is a substituted or unsubstituted monovalent group. Represents an aromatic ring, n5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and X ² may be the same or different Good.

In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl having 1 to 3 carbon atoms. Group is preferable, and a hydrogen atom and a methyl group are more preferable.

In General Formula (III-2), X ² represents a substituted or unsubstituted monovalent aromatic ring, and specific examples and preferred ranges of the aromatic ring are the same as those of X ¹ above.

  In general formula (III-2), n5 represents the integer of 1-11, 1-9 are preferable and 1-7 are more preferable.

The general formula (III-2) is preferably represented by the following general formula (III-2-1).
Formula (III-2-1)

^{R 16,} R 17 in the general formula ^{(III-2-1), R 19} , and n5 formula (III-2) ^R 16 ^in, R ^{17, R 19,} and n5 and have the same meanings as respectively, the preferred range Is the same.

The general formula (III-2) is preferably represented by the following general formula (III-2-2).
Formula (III-2-2)

  N4 represents the integer of 0-10 in general formula (III-2-2).

  In general formula (III-2-2), n4 represents the integer of 0-10, 0-8 are preferable and 0-6 are more preferable.

In the compound represented by the general formula (III), R ¹² is a group represented by the general formula (III-1-2), n2 represents an integer of 1 to 3, and n3 represents an integer of 0 to 2. It is preferable that it is an aspect to represent.

  Although the specific example of a compound represented by general formula (III) below is shown, it is not limited to the following specific examples.

The weight average molecular weight of the compound represented by the general formula (III) is preferably 200 to 1200, more preferably 250 to 1000, and particularly preferably 300 to 800.
When the molecular weight is 200 or more, there is little volatilization from the film, which is preferable. A molecular weight of 1200 or less is preferred because it is easy to keep the haze low.

Content of the compound represented by general formula (III) is 1-20 mass parts with respect to 100 mass parts of (meth) acrylic-type resin, It is preferable that it is 1-10 mass parts, 2-7 More preferably, it is 3 parts by mass, and still more preferably 3-6 parts by mass.
By setting it as the above content, the polarizing plate protective film excellent in polarizing plate durability and excellent in transparency can be obtained.

In order to allow the compounds represented by the general formula (III) having different numbers of hydroxyl groups to be hydrogen-bonded at multiple points, at least two different compounds represented by the general formula (III) are selected from each other. It is good also as a mixture containing a seed. One example is a styrenated phenol in which 1 to 3 moles of styrene are alkylated with respect to phenol, a styrenated phenol in which styrene is further alkylated at the phenyl moiety of the alkylated styrene, and an oligomer of about 2 to 4 mers of styrene. Mention may be made of mixtures with styrenated phenols alkylated to phenol.
It is preferable to set the content within the above range when two or more compounds represented by the general formula (III) are used in combination.

The compound represented by the general formula (III) can be synthesized by adding 1 equivalent or more of styrenes in the presence of an acid catalyst to 1 equivalent of phenols, and a commercially available product may be used. . Moreover, you may use the mixture obtained by the said synthesis method as it is.
As a commercial item of the compound represented by the general formula (III), “TSP”, which is a tristyrenated phenol manufactured by Sanko Co., Ltd., “PH-25”, which is a styrenated phenol manufactured by Nikko Paint Chemical Co., Ltd., and “ PH-30-90T "," Nonflex WS "which is a styrenated phenol manufactured by Seiko Chemical Co., Ltd., and the like.

The compound represented by the general formula (III) preferably contains 0.05 to 0.50 ppm of nickel on a mass basis. As described in JP-A-7-111003, nickel is mixed in the phenolic compound in the production stage. The present inventor has an effect that the action as a catalyst for oxidizing phenols is reduced by setting the nickel content of the compound represented by the general formula (III) to 0.05 to 0.50 ppm on a mass basis. I guess it can be obtained. In particular, it is considered that the compound represented by the general formula (IV) described later has an effect of enhancing the effect of suppressing film yellowing.
The nickel content of the compound represented by the general formula (III) is more preferably 0.14 to 0.50 ppm, more preferably 0.14 to 0.40 ppm, and more preferably 0.14 to 0.35 ppm on a mass basis. Further preferred.
The nickel content in the compound represented by the general formula (III) can be adjusted by an ion exchange method or direct addition.

<Compound represented by formula (IV)>
The polarizing plate protective film of the present invention comprises 0.5 to 1.9 parts by mass of the compound represented by the following general formula (IV) with respect to 100 parts by mass of the compound represented by the general formula (III). It is preferable to contain within the range.
Formula (IV)

In general formula (IV), R ²⁰ represents a substituted or unsubstituted alkyl group having 3 to ²⁰ carbon atoms, or a substituted or unsubstituted alkenyl group, and R ²¹ and R ²² are each independently a hydrogen atom or a carbon atom. It represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkenyl group represented by formulas 1 to 6, and R ²¹ and R ²² may be bonded to each other to form a cyclic structure. X represents a single bond or a carbonyl group.

According to the study of the present inventor, a (meth) acrylic resin, a phenolic compound having a specific structure having an alkyl group substituted with an aromatic ring as a substituent (a compound represented by the general formula (III)), and A polarizing plate protective film to which a specific amine / amide compound (compound represented by the general formula (IV)) is added at a specific content can suppress a decrease in orthogonal transmittance at high temperature and high humidity, and yellowing It has been found that the suppression is particularly excellent.
About the reason why the (meth) acrylic resin film to which the phenolic compound having the specific structure and the specific amine / amide compound are added at a specific content rate is particularly excellent in suppressing yellowing and reducing the durability of the polarizing plate. Although it is not certain, the present inventors presume as follows.
In other words, the phenols added as stabilizers are oxidized to quinones, which tends to cause coloration (yellowing). However, if a large amount of amine / amide compound is added to prevent this, the The plate durability deteriorates. This is presumably due to the high amine-amide compound iodine adsorptivity and the diffusion of iodine in the polarizer into the protective film. On the other hand, regarding the suppression of coloration (yellowing), amines and amides are thought to work as radical chain initiation inhibitors (presumed to trap metals etc. necessary for radical chain initiation by chelating effects). effective. In the present invention, it is considered that the use of phenols and a very small amount of an amine / amide compound can greatly improve the suppression of coloring (yellowing) without substantially reducing the durability of the polarizing plate.

In the general formula (IV), R ²⁰ represents a substituted or unsubstituted alkyl group having 4 to 21 carbon atoms, or a substituted or unsubstituted alkenyl group. The alkyl group having 4 to 21 carbon atoms is preferably an alkyl group having 6 to 20 carbon atoms, more preferably an alkyl group having 8 to 20 carbon atoms, specifically, a lauryl group, a stearyl group, or an oleyl group. Preferably, a lauryl group is more preferable. As the alkenyl group, an alkenyl group having 6 to 20 carbon atoms is preferable, an alkenyl group having 8 to 20 carbon atoms is more preferable, specifically, a lauryl group, a stearyl group, or an oleyl group is preferable, and a lauryl group is more preferable. .

In the general formula (IV), R ²¹ and R ²² each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkenyl group. The alkyl group having 1 to 6 carbon atoms is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, A butyl group is preferable, and an ethyl group, a propyl group, and a butyl group are more preferable. As this alkenyl group, a C2-C5 alkenyl group is preferable and a C2-C4 alkenyl group is more preferable.

In the general formula (IV), the substituent in the case where the alkyl group or alkenyl group in R ²⁰ , R ²¹ , and R ²² has a substituent is preferably a group selected from the following substituent group (V).
Substituent group (V)

In the substituent group (V), R ²³ , R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ each independently represents an alkyl group having 1 to 6 carbon atoms. * Represents a binding site.
R ²³ , R ²⁴ , R ²⁵ , R ²⁶ and R ²⁷ are preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, specifically, a methyl group, an ethyl group, propyl Group and butyl group are preferable, and ethyl group, propyl group and butyl group are more preferable.
Of the substituent group (V), a hydroxyl group and a carbonyl group are particularly preferred, and a hydroxyl group is most preferred.

In the general formula (IV), R ²¹ and R ²² may be bonded to each other to form a cyclic structure, and examples of the ring formed include piperidine.

It is preferable that the compound represented by the general formula (IV) is a compound represented by the following general formula (VI).
Formula (VI)

In the general formula (VI), R ²⁸ represents a substituted or unsubstituted alkyl group having 3 to 20 carbon atoms, or a substituted or unsubstituted alkenyl group, and R ²⁹ and R ³⁰ are each a hydrogen atom or a carbon atom number 1 to 1 6 represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkenyl group.

In General Formula (VI), specific examples and preferred ranges of R ²⁹ and R ³⁰ are the same as R ²¹ and R ²² in General Formula (IV).
In general formula (VI), R ²⁸ represents a substituted or unsubstituted alkyl group having 3 to 20 carbon atoms, or a substituted or unsubstituted alkenyl group, and a preferred range thereof is substituted or unsubstituted 6 to 20 carbon atoms. Or a substituted or unsubstituted alkenyl group. Examples of the alkyl group include propyl group, isopropyl group, n-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group. Examples of the alkenyl group include an allyl group and an oleyl group.

It is preferable that the compound represented by the general formula (IV) is a compound represented by the following general formula (VII).
Formula (VII)

In the general formula (VII), R ³¹ represents an alkyl group or alkenyl group having 3 to 20 carbon atoms.
Specific examples and preferred ranges of R ³¹ are the same as those for R ²⁸ .

  Specific examples of the compound represented by the general formula (IV) include lauryl diethanolamide, stearyl diethanolamide, oleyl diethanolamide and the like, and lauryl diethanolamide and stearyl diethanolamide are particularly preferable.

  In the polarizing plate protective film of the present invention, the compound represented by the general formula (IV) is in a range of 0.5 to 1.9 parts by mass with respect to 100 parts by mass of the compound represented by the general formula (III). It is preferable to contain in this, More preferably, it is 0.7-1.9 mass part, More preferably, it is 1.0-1.9 mass part, Especially preferably, it is 1.2-1.9 mass part It is. When the content of the compound represented by the general formula (IV) is 0.5 parts by mass or more with respect to 100 parts by mass of the compound represented by the general formula (III), the coloring (yellowing) of the film It is preferable from the viewpoint of suppression and is preferably 1.9 parts by mass or less from the viewpoint of polarizing plate durability.

[Polarizer]
The polarizing plate of the present invention comprises the polarizing plate protective film of the present invention. Preferably, it includes a polarizer and two polarizing plate protective films arranged on both sides of the polarizer, and at least one polarizing plate protective film is the polarizing plate protective film of the present invention.

<Polarizer>
First, the polarizer used for the polarizing plate of this invention is demonstrated.
The polarizer that can be used in the polarizing plate of the present invention is preferably composed of polyvinyl alcohol (PVA) and a dichroic molecule. However, as described in JP-A No. 11-248937, PVA and poly (polyethylene) are used. A polyvinylene polarizer in which a polyene structure is produced by dehydrating and dechlorinating vinyl chloride and then oriented can also be used.

(1-1) PVA
The PVA is preferably a polymer material obtained by saponifying polyvinyl acetate, but may contain a component copolymerizable with vinyl acetate such as unsaturated carboxylic acid, unsaturated sulfonic acid, olefins, and vinyl ethers. I do not care. In addition, modified PVA containing an acetoacetyl group, a sulfonic acid group, a carboxyl group, an oxyalkylene group, or the like can also be used.

In addition, the polarizing plate of the present invention includes a PVA film having a 1,2-glycol bond amount of 1.5 mol% or less described in Japanese Patent No. 3021494, and Japanese Patent Application Laid-Open No. 2001-316492. A PVA film having 500 or less optical foreign matters of 5 μm or more per 100 cm ² , and a PVA film having a hot-water cutting temperature spot in the TD direction of 1.5 ° C. or less of the film described in JP-A No. 2002-030163 Further, a solution prepared by mixing 1 to 100% by mass of a tri- to hexavalent polyhydric alcohol such as glycerin or a solution prepared by mixing 15% by mass or more of a plasticizer described in JP-A-06-289225 is manufactured. A filmed PVA film can be preferably used.

(1-2) dichroic molecule dichroic molecule I ₃ ^- or I ₅ ^- can be preferably used an iodine ion or a dichroic dye higher such.
In the present invention, higher-order iodine ions are particularly preferably used. Higher-order iodine ions can be found in “Applications of Polarizing Plates” by Ryo Nagata, CMC Publishing and Industrial Materials, Vol. 28, No. 7, p. 39-p. 45, PVA can be produced by immersing PVA in a solution obtained by dissolving iodine in a potassium iodide aqueous solution and / or a boric acid aqueous solution and adsorbing and orienting the PVA.
When a dichroic dye is used as the dichroic molecule, an azo dye is preferable, and a bisazo dye and a trisazo dye are particularly preferable. The dichroic dye is preferably a water-soluble dye. For this reason, a hydrophilic substituent such as a sulfonic acid group, an amino group, or a hydroxyl group is introduced into the dichroic molecule, and a free acid, or an alkali metal salt, ammonium salt, or amine is introduced. It is preferably used as a salt. Specific examples of such dichroic dyes include those described in JP-A-2007-086748.

(1-3) Boric acid The polarizing plate of the present invention contains boric acid as a crosslinking agent in the polarizer. By crosslinking the polarizer with boric acid, the stability of the complex formed from the dichroic molecule and PVA can be improved, and polarization performance deterioration under high temperature and high humidity conditions can be suppressed. The content of boric acid in the polarizer of the polarizing plate of the present invention is preferably 1 part by mass or more and 100 parts by mass or less, and more preferably 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polarizer. By controlling the content of boric acid within the above range, a polarizer with a well-balanced color can be produced.

(1-4) Film thickness of polarizer The film thickness before stretching of the polarizer is not particularly limited, but is preferably 1 μm to 1 mm, particularly preferably 10 to 200 μm, from the viewpoint of film holding stability and stretching uniformity. preferable. Further, as described in JP-A-2002-236212, a thin PVA film may be used in which the stress generated when stretching 4 to 6 times in water is 10 N or less.
The film thickness after stretching of the polarizer is 3 μm or more and 20 μm or less. It is more preferably 3 μm or more and 15 μm or less, and most preferably 3 μm or more and 10 μm or less. By setting the polarizer to the film thickness, warpage and distortion of the liquid crystal panel due to environmental humidity can be reduced.

(1-5) Film thickness of polarizing plate The film thickness of the polarizing plate of the present invention is preferably from 15 μm to 70 μm, more preferably from 15 μm to 60 μm, and most preferably from 15 μm to 50 μm. By setting the polarizing plate to the film thickness, warpage and distortion of the liquid crystal panel due to environmental humidity can be reduced.

<Polarizing plate protective film>
Next, the polarizing plate protective film used for the polarizing plate of this invention is demonstrated.

(Thickness of polarizing plate protective film)
The film thickness of the polarizing plate protective film containing the organic acid is preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm, and particularly preferably 20 μm to 60 μm.

  Here, the two polarizing plate protective films used for the polarizing plate of the present invention may be the same polarizing plate protective film or different polarizing plate protective films.

  Hereinafter, the resin and additive used for the polarizing plate protective film will be described.

<Resin>
The polarizing plate protective film is preferably a film-like resin. The resin used in the polarizing plate protective film will be described.
As resin used for the said polarizing plate protective film, well-known resin can be used and there is no restriction | limiting in particular unless it is contrary to the meaning of this invention. Examples of the resin include cellulose acylate resins, (meth) acrylic resins, and cycloolefin resins, and among them, (meth) acrylic resins are preferable. That is, the polarizing plate protective film preferably contains a (meth) acrylic resin.
The polarizing plate of the present invention preferably has at least one (meth) acrylic resin film of the present invention as a polarizing plate protective film.

[Formation of polarizer protective film]
The polarizer protective film of the present invention is preferably formed by subjecting a molding material containing a resin component containing the (meth) acrylic resin as a main component to extrusion molding (melt extrusion method such as T-die method or inflation method). Obtained by molding. Specifically, biaxial kneading using direct addition or a master batch method is preferably performed. As a kneading method, kneading is preferably performed using an extruder such as a single-screw extruder or a twin-screw extruder, a pressure kneader, or a TEM manufactured by Toshiba Machine Co., Ltd. Moreover, you may knead | mix previously what was pre-blended with the omni mixer etc.

  In the present invention, as a molding material at the time of extrusion molding, it contains a resin component containing a (meth) acrylic resin as a main component, preferably one or more phenolic, phosphorous, and sulfur antioxidants. By using a molding material containing 0.1 parts by mass or more with respect to the resin component, even if the molding temperature is 250 ° C. or higher, the coloration (yellowing) in the polarizer protective film and the generation of foaming are finally achieved. Can be sufficiently suppressed. Therefore, it is preferable to set the temperature so that the temperature of the molding material at the time of extrusion molding is 250 ° C. or higher. The temperature of the molding material at the time of extrusion molding is more preferably 250 to 300 ° C. If the temperature rises too much, decomposition of the (meth) acrylic resin may easily proceed.

  Extrusion molding does not require drying and scattering of the solvent in the adhesive used during processing, for example, the organic solvent in the adhesive for dry lamination, as in the dry lamination method. Excellent in productivity.

  As an example of a preferred embodiment of a molding method for obtaining the polarizer protective film of the present invention, a molding material is added to a biaxial kneader and extruded at a molding temperature of 250 ° C. or more to produce resin pellets. The obtained resin pellets are supplied to a single screw extruder connected to a T-die and extruded at a die temperature of 250 ° C. or more to obtain a polarizer protective film.

  When extrusion film formation is performed by the T-die method, a T-die is attached to the tip of any appropriate single-screw extruder or twin-screw extruder, and the film extruded into a film shape can be obtained as a roll-shaped film it can. At this time, it is possible to adjust the temperature of the winding roll as appropriate and apply stretching in the extruding direction so that a uniaxial stretching process can be performed. Moreover, it is also possible to add processes, such as sequential biaxial stretching and simultaneous biaxial stretching, by adding the process of extending | stretching a film in the direction perpendicular | vertical to an extrusion direction.

(Addition of additives)
The timing at which the compound represented by the general formula (III) and the compound represented by the general formula (IV) are added to the (meth) acrylic resin that is a resin raw material of the polarizing plate protective film is not particularly limited. For example, it may be added at the time of synthesis of the (meth) acrylic resin or may be mixed at the time of molding.

(Addition of UV absorber)
In this invention, you may add a ultraviolet absorber to a polarizing plate protective film from a viewpoint of deterioration prevention of a polarizing plate or a liquid crystal. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, hindered phenol compounds, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc. Examples of hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert) -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. Examples of benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6 (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2'-hydroxy-3', 5'-di-tert-amylphenyl) -5-chloro And benzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The content of the ultraviolet light inhibitor is preferably 0.1 parts by mass to 10.0 parts by mass with respect to 100 parts by mass of the polarizing plate protective film.

(Addition of other additives)
Degradation inhibitors (for example, antioxidants, peroxide decomposers, radical inhibitors, metal deactivators, acid scavengers, amines, etc.) may be added to the polarizing plate protective film. The deterioration preventing agents are described in JP-A-3-199201, JP-A-51907073, JP-A-5-194789, JP-A-5-271471, and JP-A-6-107854. Moreover, it is preferable that it is 0.01-1 mass% of content of the said deterioration inhibiting agent, and, as for the solution (dope) to prepare, it is more preferable that it is 0.01-0.2 mass%. If the content is 0.01% by mass or more, the effect of the deterioration preventing agent is sufficiently exhibited, and if the content is 1% by mass or less, the deterioration preventing agent bleeds out to the film surface (bleeding). And the like are less likely to occur. Examples of particularly preferred deterioration inhibitors include butylated hydroxytoluene (BHT) and tribenzylamine (TBA).

<Method for producing polarizer>
The method for producing the polarizer in the method for producing a polarizing plate of the present invention is not particularly limited. For example, it is preferable to form a polarizer by introducing a dichroic molecule after forming the PVA into a film. . The production of the PVA film is carried out according to the method described in [0213] to [0237] of JP-A-2007-86748, Japanese Patent Registration No. 3342516, JP-A-09-328593, JP-A-2001-302817, This can be done with reference to Japanese Patent Application Laid-Open No. 2002-144401.

  Specifically, the manufacturing method of the polarizer may be sequentially performed in the order described in the preparation process of the PVA resin solution, the casting process, the swelling process, the dyeing process, the hardening process, the stretching process, and the drying process. Particularly preferred. Further, an on-line surface inspection process may be provided during or after the aforementioned process.

(Preparation of PVA resin solution)
In the step of preparing the PVA resin solution, it is preferable to prepare a stock solution in which the PVA resin is dissolved in water or an organic solvent. The concentration of the PVA resin in the stock solution is preferably 5 to 20% by mass. For example, a method of putting a wet cake of PVA in a dissolution tank, adding a plasticizer and water as necessary, and stirring while blowing water vapor from the bottom of the tank is preferable. The internal resin temperature is preferably heated to 50 to 150 ° C., and the inside of the system may be pressurized.
Moreover, it is not necessary to add an acid to the polarizer, but it may be added, but when added, it is preferably added in this step. In addition, when adding an acid in a polarizer, you may use the same thing as the said organic acid contained in the said polarizing plate protective film.

(Casting)
In the casting step, a method of casting the PVA resin solution stock solution prepared above to form a film is generally preferably used. The casting method is not particularly limited, but the heated PVA-based resin solution stock solution is supplied to a biaxial extruder and is supported by a gear pump from discharge means (preferably a die, more preferably a T-type slit die). It is preferable to form a film by flowing upward. Moreover, there is no restriction | limiting in particular about the temperature of the resin solution discharged | emitted from die | dye.
The support is preferably a cast drum, and the drum diameter, width, rotation speed, and surface temperature are not particularly limited.
Thereafter, it is preferable to perform drying while alternately passing the back and front surfaces of the obtained roll through the drying roll.

(Swelling)
The swelling step is preferably performed only with water. However, as described in JP-A-10-153709, the optical performance is stabilized and wrinkle generation of the polarizing plate substrate in the production line is avoided. In addition, the degree of swelling of the polarizing plate substrate can be controlled by swelling the polarizing plate substrate with an aqueous boric acid solution.
Moreover, although the temperature and time of a swelling process can be defined arbitrarily, 10 to 60 degreeC and 5 to 2000 second are preferable.
In addition, you may extend slightly at the time of a swelling process, for example, the aspect extended about 1.3 times is preferable.

(staining)
For the dyeing step, the method described in JP-A-2002-86554 can be used. Further, as a dyeing method, not only immersion but any means such as application or spraying of iodine or a dye solution can be used. Further, as described in JP-A-2002-290025, a method of dyeing while stirring the iodine concentration, the dyeing bath temperature, the draw ratio in the bath, and the bath liquid in the bath may be used.
When high-order iodine ions are used as the dichroic molecule, in order to obtain a high-contrast polarizing plate, it is preferable to use a solution in which iodine is dissolved in an aqueous potassium iodide solution in order to obtain a high-contrast polarizing plate. In this case, with respect to the mass ratio of iodine and potassium iodide in the iodine-potassium iodide aqueous solution, an embodiment described in JP-A-2007-086748 can be used.
Further, as described in Japanese Patent No. 3145747, boron compounds such as boric acid and borax may be added to the dyeing solution.

(Dura mater)
In the hardening step, it is preferable to immerse in the crosslinking agent solution or apply the solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the hardening process can be performed in several steps.
As the crosslinking agent, those described in US Pat. No. 2,328,977 can be used, and as described in Japanese Patent No. 3357109, a polyhydric aldehyde is used as a crosslinking agent in order to improve dimensional stability. However, boric acids are most preferably used. When boric acid is used as the crosslinking agent used in the hardening step, metal ions may be added to the boric acid-potassium iodide aqueous solution. Zinc chloride is preferable as the metal ion. However, as described in JP-A No. 2000-35512, zinc halide such as zinc iodide, zinc sulfate such as zinc acetate is used instead of zinc chloride. It can also be used.
Alternatively, a boric acid-potassium iodide aqueous solution to which zinc chloride has been added may be prepared, and the PVA film may be immersed to perform hardening, and the method described in JP-A-2007-086748 can be used.

  Here, as a method for improving the durability under a high temperature environment, a dipping treatment using a known acidic solution may or may not be performed. Examples of the treatment with the acidic solution include methods described in JP-A-2001-83329, JP-A-6-254958, and International Publication WO2006 / 095815.

(Stretching)
For the stretching step, a longitudinal uniaxial stretching method as described in US Pat. No. 2,454,515 or the like, or a tenter method as described in JP-A-2002-86554 is preferably used. Can do. A preferable draw ratio is 2 to 12 times, and more preferably 3 to 10 times. In addition, the relationship between the draw ratio, the original fabric thickness, and the polarizer thickness is described in JP-A No. 2002-040256 (polarizer film thickness after protective film bonding / original fabric film thickness) × (total draw ratio) )> 0.17, or the relationship between the width of the polarizer when leaving the final bath and the width of the polarizer when bonding the protective film is 0.80 ≦ (protection) described in JP-A-2002-040247 It is also preferable to set the polarizer width at the time of film bonding / the width of the polarizer when the final bath is removed) ≦ 0.95.

(Dry)
As the drying step, a method known in JP-A-2002-86554 can be used, but a preferable temperature range is 30 ° C. to 100 ° C., and a preferable drying time is 30 seconds to 60 minutes. In addition, as described in Japanese Patent No. 3148513, heat treatment is performed so that the fading temperature in water is 50 ° C. or higher, or described in JP-A-07-325215 and JP-A-07-325218. As described above, aging in an atmosphere in which the temperature and humidity are controlled can be preferably performed.

  It is preferable to manufacture a polarizer having a thickness of 10 to 200 μm by such a process. In addition, control of a film thickness can be controlled by a well-known method, for example, it can control by setting the die slit width in the said casting process, and extending | stretching conditions to an appropriate value.

<Lamination method of polarizer and polarizing plate protective film>
The manufacturing method of the polarizing plate of this invention laminates | stacks two polarizing plate protective films on both surfaces of the said polarizer obtained above.
In the method for producing a polarizing plate of the present invention, a polarizing plate protective film is treated with an alkali and bonded to both sides of a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. It is preferable to prepare by a method.
Examples of the adhesive used for bonding the treated surface of the polarizing plate protective film and the polarizer include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, and vinyl latexes such as butyl acrylate. It is done.

The polarizing plate protective film of the present invention is bonded to the polarizer such that the transmission axis of the polarizer and the slow axis of the polarizing plate protective film are substantially parallel or perpendicular to each other. It is preferable.
Here, being substantially parallel means that the deviation between the direction of the main refractive index nx of the polarizing plate protective film containing the organic acid and the direction of the transmission axis of the polarizing plate is within 5 °. It is preferable that the angle is within 1 °, preferably within 0.5 °. Moreover, being substantially perpendicular means that the deviation between the direction of the main refractive index nx of the polarizing plate protective film containing the organic acid and the direction of the transmission axis of the polarizing plate is 85 ° or more and 95 ° or less. 89 ° to 91 °, preferably 89.5 ° to 90.5 °. If the deviation is within 1 °, or 89 ° or more and 90 ° or less, a decrease in polarization degree performance and light leakage under a polarizing plate crossed Nicol are preferably suppressed.

<Performance of polarizing plate>
(Orthogonal transmittance CT)
In the polarizing plate of the present invention, the orthogonal transmittance CT is preferably CT ≦ 2.0, more preferably CT ≦ 1.3, and most preferably CT ≦ 0.6 (unit is%) ).

(Orthogonal transmittance change)
Further, it is preferable that the amount of change in the orthogonal transmittance is small before and after the polarizing plate durability test.
The polarizing plate of the present invention has a change amount (%) of the orthogonal single plate transmittance of 0.05% or less when left at 60 ° C. and a relative humidity of 90% for 1000 hours, and at 105 ° C. in a Dry environment. (It is in a state where humidity is not adjusted, and in the examples of the present invention, relative humidity is 0% to 20%.) The amount of change (%) in the orthogonal single plate transmittance when allowed to stand for 50 hours is 0.05%. The following is preferable.

Here, the change amount of the orthogonal transmittance is calculated by the following equation.
Change amount of orthogonal transmittance (%) = {(Orthogonal transmittance after durability test (%) − Orthogonal transmittance before durability test (%))
If the range of the change amount of the orthogonal transmittance is satisfied, the stability of the polarizing plate can be ensured during use or storage for a long time under high temperature and high humidity and high temperature and low humidity.

In the present invention, the orthogonal transmittance CT of the polarizing plate was measured using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation. In the measurement, measurement was performed at 410 nm, and the average value of 10 measurements was used.
Here, in the polarizing plate durability test, two samples (about 5 cm × 5 cm) in which a polarizing plate is pasted on glass so that a polarizing plate protective film satisfying the requirements of the present invention is on the air interface side are prepared. To do. In the single plate orthogonal transmittance measurement, the sample is set with the polarizing film side of the present invention facing the light source. Two samples are measured respectively, and the average value is defined as a single plate orthogonal transmittance.

(Other characteristics)
Other preferable optical characteristics and the like of the polarizing plate of the present invention are described in [0238] to [0255] of JP-A-2007-086748, and it is preferable to satisfy these characteristics.

<Shape and configuration>
The shape of the polarizing plate of the present invention is not only a polarizing plate in the form of a film piece cut into a size that can be incorporated into a liquid crystal display device as it is, but also produced in a long shape by continuous production, and in a roll shape. A polarizing plate in a rolled up mode (for example, a roll length of 2500 m or longer or 3900 m or longer) is also included. In order to use for a large-screen liquid crystal display device, the width of the polarizing plate is preferably 1470 mm or more.

The polarizing plate of the present invention is composed of a polarizer and a polarizing plate protective film that protects both sides of the polarizer, and further comprises a protective film on one side of the polarizing plate and a separate film on the other side. It is also preferred that
The protect film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate, product inspection, and the like. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the contact bonding layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.
Hereinafter, the details of the polarizer and the two polarizing plate protective films that can be used in the polarizing plate of the present invention will be described.

<Functionalization of polarizing plate>
The polarizing plate of the present invention is a function that is combined with an optical film having functional layers such as an antireflection film, a brightness enhancement film, a hard coat layer, a forward scattering layer, and an antiglare (antiglare) layer for improving the visibility of the display. It is also preferably used as a polarizing plate. The antireflection film, brightness enhancement film, other functional optical film, hard coat layer, forward scattering layer, and antiglare layer for functionalization are described in [0257] to [0276] of JP-A-2007-86748. Thus, a functionalized polarizing plate can be produced based on these descriptions.

(3-1) Antireflection film The polarizing plate of the present invention can be used in combination with an antireflection film. As the antireflection film, either a film having a reflectivity of about 1.5% only by applying a single layer of a low refractive index material such as a fluoropolymer, or a film having a reflectivity of 1% or less using multilayer interference of a thin film is used. it can. In the present invention, a structure in which a low refractive index layer and at least one layer having a higher refractive index than that of the low refractive index layer (that is, a high refractive index layer and a middle refractive index layer) is laminated on a transparent support is preferably used. The In addition, Nitto Technical Report, vol. 38, no. 1, May, 2000, pages 26 to 28 and JP-A No. 2002-301783.

The refractive index of each layer satisfies the following relationship.
Refractive index of high refractive index layer> refractive index of medium refractive index layer> refractive index of transparent support> refractive index of low refractive index layer

  As the transparent support used for the antireflection film, a transparent polymer film used for the protective film for the polarizer described above can be preferably used.

  The refractive index of the low refractive index layer is preferably 1.20 to 1.55, more preferably 1.30 to 1.50. The low refractive index layer is preferably used as an outermost layer having scratch resistance and antifouling properties. In order to improve the scratch resistance, it is also preferable to impart slipperiness to the surface using a material such as a silicone-containing compound containing a silicone group or a fluorine-containing compound containing fluorine.

Examples of the fluorine-containing compound include JP-A-9-222503 [0018] to [0026], JP-A-11-38202 [0019] to [0030], JP-A 2001-40284 [0027] to [0027]. [0028] The compounds described in JP 2000-284102 A and the like can be preferably used.
The silicone-containing compound is preferably a compound having a polysiloxane structure, such as reactive silicone (for example, Silaplane (manufactured by Chisso Corporation), polysiloxane containing silanol groups at both ends (Japanese Patent Laid-Open No. 11-258403), etc. Alternatively, an organometallic compound such as a silane coupling agent and a specific fluorine-containing hydrocarbon group-containing silane coupling agent may be cured by a condensation reaction in the presence of a catalyst (Japanese Patent Laid-Open No. 58-86). 142958, 58-147483, 58-147484, JP-A-9-157582, 11-106704, JP-A-2000-117902, 2001-48590, 2002 -53804 publication etc.).
The low refractive index layer has an average primary particle diameter of 1 to 150 nm such as fillers (for example, silicon dioxide (silica), fluorine-containing particles (magnesium fluoride, calcium fluoride, barium fluoride)) as additives other than the above. And a low refractive index inorganic compound, organic fine particles described in [0020] to [0038] of JP-A No. 11-3820, etc.), silane coupling agents, slip agents, surfactants, and the like are preferably included. Can do.

The low refractive index layer may be formed by a vapor phase method (vacuum deposition method, sputtering method, ion plating method, plasma CVD method, etc.), but may be formed by a coating method because it can be manufactured at low cost. preferable. As the coating method, dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, and micro gravure can be preferably used.
The film thickness of the low refractive index layer is preferably 30 to 200 nm, more preferably 50 to 150 nm, and most preferably 60 to 120 nm.

The medium refractive index layer and the high refractive index layer preferably have a structure in which ultrafine particles of high refractive index having an average particle size of 100 nm or less are dispersed in a matrix material. Inorganic compound fine particles having a high refractive index include inorganic compounds having a refractive index of 1.65 or more, for example, oxides such as Ti, Zn, Sb, Sn, Zr, Ce, Ta, La, and In, and metal atoms thereof. A composite oxide or the like can be preferably used.
Such ultrafine particles may be obtained by treating the particle surface with a surface treatment agent (silane coupling agent, etc .: JP-A Nos. 11-295503, 11-153703, 2000-9908, anionic compounds) Or an organic metal coupling agent (Japanese Patent Laid-Open No. 2001-310432, etc.), a core-shell structure having high refractive index particles as a core (Japanese Patent Laid-Open No. 2001-166104, etc.), or a specific dispersant is used together (for example, , JP-A-11-153703, US Pat. No. 6,210,858B1, JP-A-2002-277760, etc.).

As the matrix material, conventionally known thermoplastic resins, curable resin films, and the like can be used, but JP-A 2000-47004, 2001-315242, 2001-31871, 2001-296401. It is also possible to use a curable film obtained from a polyfunctional material described in JP-A-2001-293818 or a metal alkoxide composition described in JP-A-2001-293818.
The refractive index of the high refractive index layer is preferably 1.70 to 2.20. The thickness of the high refractive index layer is preferably 5 nm to 10 μm, and more preferably 10 nm to 1 μm.
The refractive index of the medium refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.50 to 1.70.

  The haze of the antireflection film is preferably 5% or less, more preferably 3% or less. Further, the strength of the film is preferably H or more, more preferably 2H or more, and most preferably 3H or more in a pencil hardness test according to JIS K5400.

(3-2) Brightness Improvement Film The polarizing plate of the present invention can be used in combination with a brightness enhancement film. The brightness enhancement film has a function of separating circularly polarized light or linearly polarized light, and is disposed between the polarizing plate and the backlight, and reflects or backscatters one circularly polarized light or linearly polarized light to the backlight side. The re-reflected light from the backlight part partially changes the polarization state and partially transmits when it re-enters the brightness enhancement film and the polarizing plate. By repeating this process, the light utilization rate is improved. The front luminance is improved to about 1.4 times. As the brightness enhancement film, an anisotropic reflection method and an anisotropic scattering method are known, and both can be combined with the polarizing plate in the present invention.

  In the anisotropic reflection system, a brightness enhancement film having anisotropy in reflectance and transmittance is known by laminating a uniaxially stretched film and an unstretched film in multiple layers and increasing the difference in refractive index in the stretching direction. Multilayer film systems using the principle of dielectric mirrors (described in the specifications of WO95 / 17691, WO95 / 17692, and WO95 / 17699) and cholesteric liquid crystals A system (European Patent No. 606940A2 specification, JP-A-8-271731) is known. DBEF-E, DBEF-D, and DBEF-M (all manufactured by 3M) are used as multi-layer brightness enhancement films using the principle of dielectric mirrors, and NIPOCS (Nitto Denko Corporation) as a cholesteric liquid crystal brightness enhancement film. )) Is preferably used in the present invention. For NIPOCS, see Nitto Giho, vol. 38, no. 1, May, 2000, pages 19 to 21 and the like.

  Further, in the present invention, the specifications of International Publication No. 97/32223, International Publication No. 97/32224, International Publication No. 97/32225, International Publication No. 97/32226, and Japanese Patent Application Laid-Open No. 9-274108. Used in combination with a brightness enhancement film of an anisotropic scattering method in which a positive intrinsic birefringent polymer and a negative intrinsic birefringent polymer are blended and uniaxially stretched as described in each publication of JP-A-11-174231 It is also preferable to do. As the anisotropic scattering system brightness enhancement film, DRPF-H (manufactured by 3M) is preferable.

  The polarizing plate of the present invention is further combined with a functional optical film provided with a hard coat layer, a forward scattering layer, an antiglare (antiglare) layer, a gas barrier layer, a slipping layer, an antistatic layer, an undercoat layer, a protective layer and the like. It is also preferable to use it. These functional layers are also preferably used in combination with each other in the same layer as the antireflection layer or the optically anisotropic layer in the above-described antireflection film. These functional layers can be used by providing them on one side or both sides of the polarizer side and the surface opposite to the polarizer (the surface on the air side).

(3-3) Hard Coat Layer The polarizing plate of the present invention is preferably combined with a functional optical film having a hard coat layer provided on the surface of a transparent support in order to impart mechanical strength such as scratch resistance. . When the hard coat layer is applied to the above-described antireflection film, it is particularly preferable to provide it between the transparent support and the high refractive index layer.
The hard coat layer is preferably formed by a crosslinking reaction or a polymerization reaction of a curable compound by light and / or heat. The curable functional group is preferably a photopolymerizable functional group, or the hydrolyzable functional group-containing organometallic compound is preferably an organic alkoxysilyl compound. As a specific constituent composition of the hard coat layer, for example, those described in JP-A-2002-144913, JP-A-2000-9908, WO 00/46617, etc. can be preferably used.
The film thickness of the hard coat layer is preferably 0.2 μm to 100 μm.
The strength of the hard coat layer is preferably H or higher, more preferably 2H or higher, and most preferably 3H or higher in a pencil hardness test according to JIS K5400. Further, in the Taber test according to JIS K5400, the smaller the wear amount of the test piece before and after the test, the better.

  As the material for forming the hard coat layer, a compound containing an ethylenically unsaturated group or a compound containing a ring-opening polymerizable group can be used, and these compounds can be used alone or in combination. Preferred examples of the compound containing an ethylenically unsaturated group include ethylene glycol diacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol. Polyacrylates of polyols such as hexaacrylate; epoxy acrylates such as diacrylate of bisphenol A diglycidyl ether, diacrylate of hexanediol diglycidyl ether; by reaction of hydroxyl group-containing acrylates such as polyisocyanate and hydroxyethyl acrylate The obtained urethane acrylate can be mentioned as a preferred compound.Moreover, as a commercially available compound, EB-600, EB-40, EB-140, EB-1150, EB-1290K, IRR214, EB-2220, TMPTA, TMPTMA (above, Daicel UCB Co., Ltd. product), UV -6300, UV-1700B (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and the like.

  Preferred examples of the compound containing a ring-opening polymerizable group include ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether, glycerol triglycidyl ether as glycidyl ethers. Triglycidyl trishydroxyethyl isocyanurate, sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, polyglycidyl ether of phenol novolac resin, etc. Celoxide 2021P, Celoxide 2081, Epoxide GT-301, Epolide GT-401, EHPE3150CE (above, Oxetane, OXT-121, OXT-221, OX-SQ, PNOX-1009 (above, manufactured by Toagosei Co., Ltd.), etc. Can be mentioned. In addition, a polymer of glycidyl (meth) acrylate or a copolymer of a monomer that can be copolymerized with glycidyl (meth) acrylate may be used for the hard coat layer.

  In the hard coat layer, oxide fine particles such as silicon, titanium, zirconium, and aluminum are used to reduce curing shrinkage of the hard coat layer, improve adhesion to the substrate, and reduce curling of the hard coat treated article in the present invention. It is also preferable to add crosslinked fine particles such as crosslinked fine particles such as polyethylene, polystyrene, poly (meth) acrylic acid esters, polydimethylsiloxane, etc., and fine organic particles such as fine crosslinked rubber particles such as SBR and NBR. The average particle size of these crosslinked fine particles is preferably 1 nm to 20000 nm. Further, the shape of the crosslinked fine particles can be used without particular limitation, such as a spherical shape, a rod shape, a needle shape, or a plate shape. The content of the fine particles is preferably 60% by volume or less of the hard coat layer after curing, and more preferably 40% by volume or less.

  In the case of adding the inorganic fine particles described above, since the affinity with the binder polymer is generally poor, it contains a metal such as silicon, aluminum, titanium, and the alkoxide group, carboxylic acid group, sulfonic acid group, phosphonic acid group, etc. It is also preferable to perform a surface treatment using a surface treatment agent having a functional group of

  The hard coat layer is preferably cured using heat or active energy rays. Among them, active energy rays such as radiation, gamma rays, alpha rays, electron rays, and ultraviolet rays are more preferred, and safety and productivity are improved. In view of the above, it is particularly preferable to use an electron beam or ultraviolet rays. In the case of curing with heat, in consideration of the heat resistance of the plastic itself, the heating temperature is preferably 140 ° C. or lower, more preferably 100 ° C. or lower.

(3-4) Forward scattering layer The forward scattering layer is used to improve the viewing angle characteristics (hue and luminance distribution) in the vertical and horizontal directions when the polarizing plate of the present invention is applied to a liquid crystal display device. In the present invention, the forward scattering layer preferably has a configuration in which fine particles having different refractive indexes are dispersed in a binder. Japanese Patent Laid-Open No. 2000-199809, Japanese Patent Laid-Open No. 2002-107512, etc. in which the haze value is defined as 40% or more can be used. Moreover, in order to control the viewing angle characteristics of haze, the polarizing plate in the present invention should be used in combination with “Lumisty” described in Sumitomo Chemical Co., Ltd. Technical Report “Optical Functional Film” on pages 31-39. Can also be preferably performed.

(3-5) Antiglare layer The antiglare (antiglare) layer is used to scatter reflected light and prevent reflection. The antiglare function is obtained by forming irregularities on the outermost surface (display side) of the liquid crystal display device. The haze of the optical film having an antiglare function is preferably 3 to 30%, more preferably 5 to 20%, and most preferably 7 to 20%.
The method for forming irregularities on the film surface is, for example, a method of forming irregularities on the film surface by adding fine particles (for example, JP 2000-271878 A), relatively large particles (particle size 0.05-2 μm). ) Is added in a small amount (0.1 to 50% by mass) (for example, Japanese Patent Application Laid-Open Nos. 2000-281410, 2000-95893, 2001-100004, and 2001). No. 281407, etc.), a method of physically transferring the uneven shape onto the film surface (for example, as an embossing method, JP-A-63-278839, JP-A-11-183710, JP-A-2000-275401) Etc.) can be preferably used.

[Liquid Crystal Display]
Next, the liquid crystal display device of the present invention will be described.
The liquid crystal display device of the present invention includes at least one polarizing plate of the present invention.

  FIG. 1 shows an example of a liquid crystal display device of the present invention. In FIG. 1, a liquid crystal display device 10 includes a liquid crystal cell having a liquid crystal layer 5 and a liquid crystal cell upper electrode substrate 3 and a liquid crystal cell lower electrode substrate 6 disposed above and below, and upper polarizing plates disposed on both sides of the liquid crystal cell. 1 and the lower polarizing plate 8. A color filter may be disposed between the liquid crystal cell and each polarizing plate. When the liquid crystal display device 10 is used as a transmission type, a cold cathode or hot cathode fluorescent tube, or a backlight having a light emitting diode, a field emission element, or an electroluminescent element as a light source is disposed on the back surface.

The upper polarizing plate 1 and the lower polarizing plate 8 each have a structure in which a polarizer is sandwiched between two polarizing plate protective films, and the liquid crystal display device 10 of the present invention includes at least one polarizing plate. Is preferably the polarizing plate of the present invention. The liquid crystal display device 10 of the present invention is preferably laminated from the outside of the device (the side far from the liquid crystal cell) in the order of the polarizing plate protective film of the present invention, a polarizer, and a general transparent protective film.
The liquid crystal display device 10 includes an image direct view type, an image projection type, and a light modulation type. The present invention is effective for an active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as TFT or MIM. Of course, it is also effective in a passive matrix liquid crystal display device typified by STN mode called time-division driving.

(VA mode)
The liquid crystal cell of the liquid crystal display device of the present invention is preferably in the VA mode.
In the VA mode, the dielectric anisotropy between the upper and lower substrates is negative, and a liquid crystal having Δn = 0.0813 and Δε = −4.6 is rubbed to provide a director indicating the alignment direction of the liquid crystal molecules, so-called tilt angle is about Fabricate at 89 °. The thickness d of the liquid crystal layer 5 in FIG. 1 is preferably set to about 3.5 μm. Here, the brightness at the time of white display changes depending on the magnitude of the product Δnd of the thickness d and the refractive index anisotropy Δn. Therefore, in order to obtain the maximum brightness, the film thickness of the liquid crystal layer is set to be in the range of 0.2 μm to 0.5 μm.

  The absorption axis 2 of the upper polarizing plate 1 of the liquid crystal cell and the absorption axis 9 of the lower polarizing plate 8 are laminated substantially orthogonally. A transparent electrode (not shown) is formed inside each alignment film of the liquid crystal cell upper electrode substrate 3 and the liquid crystal cell lower electrode substrate 6, but in a non-driving state where no driving voltage is applied to the electrodes, the liquid crystal layer 5 The liquid crystal molecules therein are aligned substantially perpendicular to the substrate surface, and as a result, the polarization state of the light passing through the liquid crystal panel hardly changes. That is, the liquid crystal display device realizes an ideal black display in the non-driven state. On the other hand, in the driving state, the liquid crystal molecules are inclined in a direction parallel to the substrate surface, and the light passing through the liquid crystal panel changes the polarization state by the inclined liquid crystal molecules. In other words, in the liquid crystal display device, white display is obtained in the driving state. In FIG. 1, reference numerals 4 and 7 denote orientation control directions.

Here, since an electric field is applied between the upper and lower substrates, it is preferable to use a liquid crystal material having a negative dielectric anisotropy so that liquid crystal molecules respond perpendicularly to the electric field direction. When an electrode is disposed on one substrate and an electric field is applied in a lateral direction parallel to the substrate surface, a liquid crystal material having a positive dielectric anisotropy is used.
In addition, in a VA mode liquid crystal display device, the addition of a chiral agent generally used in a TN mode liquid crystal display device is rarely used to degrade dynamic response characteristics, but in order to reduce alignment defects. Sometimes added.

  The features of the VA mode are high-speed response and high contrast. However, the contrast is high in the front, but there is a problem that it is deteriorated in the oblique direction. During black display, the liquid crystal molecules are aligned perpendicular to the substrate surface. When observed from the front, the liquid crystal molecules have almost no birefringence, so the transmittance is low and a high contrast can be obtained. However, when observed obliquely, birefringence occurs in the liquid crystal molecules. Further, the crossing angle of the upper and lower polarizing plate absorption axes is 90 ° perpendicular to the front, but is larger than 90 ° when viewed from an oblique direction. Because of these two factors, leakage light occurs in the oblique direction, and the contrast is lowered.

  In addition, the liquid crystal molecules are tilted during white display, but the birefringence of the liquid crystal molecules when viewed from an oblique direction differs between the tilt direction and the opposite direction, resulting in differences in luminance and color tone. In order to solve this, it is also preferable to adopt a structure called multi-domain in which one pixel of a liquid crystal display device is divided into a plurality of regions.

(Multi-domain)
For example, in the VA system, the viewing angle characteristics are averaged by inclining liquid crystal molecules into a plurality of different regions within one pixel by applying an electric field. In order to divide the orientation within one pixel, the electrode is provided with slits or protrusions, and the electric field direction is changed or the electric field density is biased. In order to obtain a uniform viewing angle in all directions, the number of divisions may be increased, but a substantially uniform viewing angle can be obtained by dividing into four or eight or more. In particular, it is preferable that the polarizing plate absorption axis can be set at an arbitrary angle when dividing into eight.

  Also, the liquid crystal molecules are difficult to respond at the alignment division region boundary. For this reason, in normally black display, since black display is maintained, a reduction in luminance becomes a problem. Therefore, it is possible to reduce the boundary region by adding a chiral agent to the liquid crystal material.

  The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

(Production of acrylic resin pellets)
In a 30 L reaction kettle equipped with a stirrer, temperature sensor, cooling pipe, and nitrogen introduction pipe, 7000 g of methyl methacrylate (MMA) and 1000 g of 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] benzo Triazole, 2000 g of methyl 2- (hydroxymethyl) acrylate (MHMA) and 10000 g of toluene were charged, and the temperature was raised to 105 ° C. through nitrogen, and when refluxed, 10.0 g of tertiary amyl par was used as an initiator. While adding oxyisonononanoate (Arkema Yoshitomi, trade name: Lupazole 570), a solution comprising 20.0 g of initiator and 100 g of toluene was added dropwise over 4 hours under reflux (about 105 to 110 ° C. ), Followed by aging for 4 hours.

  To the obtained polymer solution, 10 g of stearyl phosphate / distearyl phosphate mixture (manufactured by Sakai Chemicals, trade name: Phoslex A-18) was added and cyclized under reflux (about 90 to 110 ° C.) for 5 hours. A condensation reaction was performed. Subsequently, the polymer solution obtained by the cyclization condensation reaction was subjected to a vent having a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1, and a forevent number of 4 It is introduced into a type screw twin screw extruder (Φ = 29.75 mm, L / D = 30) at a processing rate of 2.0 kg / hour in terms of resin amount, and cyclization condensation reaction and devolatilization are carried out in the extruder. By extrusion, transparent lactone ring-containing acrylic resin pellets (A) were obtained (Mw = 200000).

  The lactone cyclization rate of the lactone ring-containing acrylic resin pellet (A) was 97.0%.

Example 101
100 parts by mass of the acrylic resin pellet (A) is mixed with 4 parts by mass of TSP (styrenated phenol manufactured by Sanko Co., Ltd.) at 230 ° C. in a biaxial kneader to produce a resin pellet (101). did.

  The obtained resin pellet (101) was dried at 800 Pa (6 Torr) at 100 ° C. for 12 hours, extruded from a T die at a die temperature of 290 ° C. with a single screw extruder, and a polarizing plate protective film having a film thickness of 60 μm ( 101).

<Production of polarizer>
After immersing a polyvinyl alcohol film having a film thickness of 75 μm made of polyvinyl alcohol having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% or more in pure water at 30 ° C., the mass ratio of iodine / potassium iodide / water is It was immersed in an aqueous solution of 0.02 / 2/100 at 30 ° C. Then, it immersed at 56.5 degreeC in the aqueous solution whose mass ratio of potassium iodide / boric acid / water is 12/5/100. Subsequently, it was washed with pure water at 8 ° C. and then dried at 65 ° C. to obtain a polarizing film (polarizer) in which iodine was adsorbed and oriented on a polyvinyl alcohol film. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

(Preparation of polarizing plate)
A polarizing plate protective film (101) was bonded to one side of the polarizer obtained above using a SK adhesive sheet manufactured by Soken Chemical Co., Ltd.
A commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Film Co., Ltd.) was saponified. A commercially available cellulose triacetate film after saponification treatment was attached to the surface of the polarizer opposite to the side to which the produced polarizing plate protective film (101) was attached, using a polyvinyl alcohol-based adhesive. Each of the polyvinyl alcohol-based adhesives was applied to the polarizing plate protective film side and dried at 70 ° C. for 10 minutes to obtain a polarizing plate.
Thus, the polarizing plate of Example 101 was produced.

[Examples 102 to 133, Comparative Examples 201 to 206]
[Preparation of polarizing plate protective film]
In Example 101, the same procedure was carried out except that the type and content of the additive compound (“Additive A” as TSP, “Additive B”) and the film thickness were changed as shown in Table 1 below. The polarizing plate protective film used for the polarizing plate of Examples 102-133 and Comparative Examples 201-206 was manufactured, respectively.

The TSP used as “Additive A” was adjusted as follows.
<TSP used in Examples 101 and 113 to 119>
100 parts by mass of TSP (product of Sanko Co., Ltd.) of Example 102 and 0.000044 parts by mass of nickel (II) chloride were dissolved in 1000 parts by mass of dichloromethane. The solution was dried at 140 ° C. for 2 hours to obtain TSP (Ni content: 0.35 ppm).
<TSP used in Example 120>
100 parts by mass of TSP (product of Sanko Co., Ltd.) of Example 102 and 0.000110 parts by mass of nickel (II) chloride were dissolved in 1000 parts by mass of dichloromethane. The solution was dried at 140 ° C. for 2 hours to obtain TSP of Example 120 (Ni content 0.65 ppm).

[Preparation of polarizing plate]
Instead of the polarizing plate protective film 101, a polarizing plate was prepared in the same manner as in Example 101, except that the polarizing plate protective film used in the polarizing plates of Examples 102 to 133 and Comparative Examples 201 to 206 was used. The polarizing plates of Examples and Comparative Examples were produced.

[Comparative Example 211]
[Preparation of polarizing plate]
A saponified cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Film Co., Ltd.) was attached to one side of a polarizer produced in the same manner as in Example 101 using a polyvinyl alcohol adhesive. Furthermore, a commercially available polyethylene terephthalate film (manufactured by Teijin, trade name “Teijin Tetron Film-K”) is applied to the surface of the polarizer opposite to the side where the commercially available cellulose triacetate film is attached. ) A polarizing plate of Comparative Example 211 was prepared by using an SK pressure-sensitive adhesive sheet.

[Evaluation]
<Evaluation of film coloring (yellowing)>
About the polarizing plate protective film of each Example produced above and a comparative example, it is 72 in 105 degreeC and Dry environment (it is the state which is not adjusting humidity, and relative humidity is 0%-20% in the Example in this invention). After storage for a period of time, 10 sheets were stacked and the hue b * was measured using a spectrophotometer UV3150 manufactured by Shimadzu Corporation. The results are shown in Table 1 below. When the value of hue b * increases to the minus side, the transmitted light increases in blue, and when it increases toward the plus side, the yellowness increases.
A: b * is less than 4.0 B: b * is 4.0 or more and less than 8.0 C: b * is 8.0 or more

<Evaluation of polarizing plate durability>
About the polarizing plate of each Example and Comparative Example produced above, the orthogonal transmittance CT of the polarizer at a wavelength of 410 nm was measured using an automatic polarizing film measuring device VAP-7070 manufactured by JASCO Corporation and measured 10 times. The average value of was used.
The polarizing plate durability test was performed as follows in a form in which the polarizing plate was attached to glass and the polarizing plate protective film of the present invention was attached via an adhesive so as to be on the air interface side. Two samples (about 5 cm × 5 cm) each having a polarizing plate attached on glass were prepared. In the single plate orthogonal transmittance measurement, the glass side of this sample is set facing the light source and measured. Two samples were measured respectively, and the average value was taken as the orthogonal transmittance of the polarizing plate.
Then, the orthogonal transmittance was measured by the same method after storing for 1000 hours in an environment of 60 ° C. and 90% relative humidity. The change of the orthogonal transmittance before and after aging was determined, and the result is shown in Table 1 below as the polarizing plate durability.
Here, the change amount of the orthogonal transmittance is calculated by the following equation.
Change amount of orthogonal transmittance (%) = {(Orthogonal transmittance after durability test (%) − Orthogonal transmittance before durability test (%))
A: Change in orthogonal transmittance is less than 0.06% B: Change in orthogonal transmittance is 0.06% or more and less than 0.08% C: Change in orthogonal transmittance is 0.08% or more

<Method for quantifying the nickel content of phenolic compounds>
About the phenolic compound which is "additive A" of Table 1, 0.1 g of samples were extract | collected and air-dried for 60 minutes. 3 ml of 70% nitric acid aqueous solution was added to the sample, and ashed at 240 ° C. using a microwave. Thereafter, water was added to make the total amount 50 ml, and the content of nickel was quantified using ICP-OES (Optima 7300V manufactured by PerkinElmer).

As the styrenated phenol corresponding to the compound represented by the general formula (III), “TSP” manufactured by Sanko Co., Ltd., “PH-25” and “PH-30-90T” manufactured by Nikko Paint Chemical Co., Ltd., Seiko Co., Ltd. “Nonflex WS” manufactured by Chemical Co., Ltd. was used.
As the coumarone resin, “V-120S” manufactured by Nihon Paint Chemical Co., Ltd. was used.
“Poem K-37V” manufactured by Riken Vitamin Co., Ltd. was used as the glycerol citrate oleate corresponding to the general formula (3).
“Stearer LAS” used in the comparative examples is manufactured by Seiko Chemical Co., Ltd., “irganox 1076” is manufactured by BASF, and “Teijin Tetron Film-K” is a PET film manufactured by Teijin Limited.

  From Table 1 above, it was found that the polarizing plate protective film of each Example was suppressed in coloring and had good polarizing plate durability.

  Examples using other (meth) acrylic resins are shown below.

(Production of imidized resin pellets)
An imidized resin was obtained by the methods [0173] to [0176] of JP2011-138119A. The imidized resin is a (meth) acrylic resin having a glutarimide ring structure in the main chain.

  When the imidization rate was measured about the imidized resin, the imidation rate was 4 mol%.

Here, the imidation ratio represents the ratio of the imide carbonyl group in all the carbonyl groups. The imidation ratio was determined by measuring the resin using ¹ H-NMR, and the peak area A derived from the O—CH ₃ proton of methyl methacrylate in the vicinity of 3.5 to 3.8 ppm and 3.0 to 3. than the area B of the peak derived from N-CH ₃ protons of glutarimide near 3 ppm, were determined by the following equation.

  Imidization rate (mol%) = B / (A + B) × 100

  Imidized resin pellets (B) were obtained using a single-screw extruder for imidized resin.

Example 134
4 parts by mass of 1-benzyl-5-phenylbarbituric acid is mixed at 230 ° C. in a biaxial kneader with respect to 100 parts by mass of the imidized resin pellet (B), and the imidized resin pellet (134) is obtained. Produced.

  The imidized resin pellet (134) produced above was melt-extruded from a coat hanger type T die using a twin screw extruder to produce a polarizing plate protective film (134) having a thickness of 60 μm.

Example 135
PMMA (polymethyl methacrylate) resin (Delpet 80N manufactured by Asahi Kasei Chemicals Corporation) is dried with a 90 ° C. vacuum dryer to a moisture content of 0.03% or less, and then PMMA (polymethyl methacrylate) resin. 4 parts by mass of 1-benzyl-5-phenylbarbituric acid with respect to 100 parts by mass, 0.3 parts by mass of a stabilizer (Irganox 1010 (manufactured by Ciba-Gaigi Co., Ltd.)) And mixed to produce PMMA resin pellets (135).

  The PMMA resin pellet (135) produced above was melt-extruded from a coat hanger type T die using a twin screw extruder to produce a polarizing plate protective film (135) having a film thickness of 60 μm.

Example 136
A (meth) acrylic resin having a maleic anhydride ring structure in the main chain instead of PMMA (polymethylmethacrylate) resin (Delpet 980N manufactured by Asahi Kasei Chemicals Corporation, methyl methacrylate 67 mol% in all monomers, styrene 18 mol% Except for using 15 mol% of maleic anhydride, Tg = 117 ° C.), pellet preparation and film formation were carried out in the same manner as in Example 135 to prepare a polarizing plate protective film (136) having a film thickness of 60 μm.

Example 137
(Preparation of dope 137)
The composition described below was put into a mixing tank and stirred while heating to dissolve each component to prepare a dope.
(Composition of dope 137)
PMMA (polymethyl methacrylate) resin (trade name: Dianal BR88, manufactured by Mitsubishi Rayon Co., Ltd. (mass average molecular weight 1500,000)
100 parts by mass 1-benzyl-5-phenylbarbituric acid Exemplary compound (3-3) 4.0 parts by mass Dichloromethane 502 parts by mass Methanol 44 parts by mass

  Using the band casting apparatus, the prepared dope was uniformly cast from a casting die to a stainless steel endless band (casting support) having a width of 2000 mm. When the amount of residual solvent in the dope reaches 15% by mass, it is peeled off from the casting support as a polymer film, conveyed without being actively stretched by a tenter, and dried at 120 ° C. in a drying zone. A polarizing plate protective film 137 having a film thickness of 60 μm was prepared.

[Preparation of polarizing plate]
A polarizing plate was prepared in the same manner as in Example 101 except that the polarizing plate protective film used for the polarizing plates of Examples 134 to 137 was used instead of the polarizing plate protective film 101, and the polarizing plates of the respective examples were prepared. did.

  These polarizing plates were evaluated in the same manner as described above. Furthermore, the following film folding resistance evaluation and heat resistance evaluation were performed. The results are shown in Table 2.

<Evaluation of film folding resistance>
A film sample was cut out in a size of 100 mm long × 10 mm wide, bent at the center, and confirmed the ease of breakage of the film. In addition, when the easiness to break differs depending on the setting method in the vertical direction or the horizontal direction, the evaluation result that is more likely to break is used.
A: The film is difficult to break.
B: When the film is bent greatly, it may break.
C: When a film is bent moderately, it may break.
D: The film breaks only by bending the film small.

<Evaluation of film heat resistance>
The film sample was left for 72 hours in an atmosphere of 80 ° C. in a DRY environment (in a state where humidity was not adjusted, and relative humidity was 0% to 20% in the examples of the present invention), and the degree of film deformation was visually observed. confirmed.
A: No film deformation was confirmed.
B: The degree of film deformation is very small.
C: The degree of film deformation is small.
D: Film deformation is remarkable.

  From the above Table 2, it was found that the polarizing plate protective film of each example was suppressed in coloring and had good polarizing plate durability. In particular, (meth) acrylic resins having a cyclic structure in the main chain have better folding resistance and heat resistance, and (meth) acrylic having a lactone ring structure among (meth) acrylic resins having a cyclic structure in the main chain. It has been found that the (meth) acrylic resin having a methacrylic resin and a (meth) acrylic resin having a glutarimide ring structure are further superior in folding resistance and heat resistance, and the (meth) acrylic resin having a lactone ring structure is particularly excellent.

  In Examples 109 and 134 to 137, 1-benzyl-5-phenylbarbituric acid as additive A was added in an amount of 4.0 parts by mass with respect to 100 parts by mass of (meth) acrylic resin. Although the film performances of the different resins were compared, the above-mentioned Examples 109, 134 to 137 and Examples 101 to 108, 110 to 112, and 118 to 127, in which the total contents of Additives A and B were substantially the same, A similar tendency was obtained even when films with different (meth) acrylic resins were prepared in the same manner as in Examples 109 and 134 to 137 and the evaluation results were compared.

  Furthermore, about Example 113-117 in which content of additive A differs from the said Example 109 and 134-137, the temperature conditions of a film heat resistance test are within the range of 60-100 degreeC, and the film by (meth) acrylic-type resin difference Except for changing the conditions as appropriate so that the difference in heat resistance can be confirmed, the same tendency is observed even if a film with a different (meth) methacrylic resin is prepared and the evaluation results are compared in the same manner as in Examples 109 and 134 to 137. was gotten.

DESCRIPTION OF SYMBOLS 1 Upper polarizing plate 2 Upper polarizing plate Absorption axis direction 3 Liquid crystal cell upper electrode substrate 4 Upper substrate alignment control direction 5 Liquid crystal layer 6 Liquid crystal cell lower electrode substrate 7 Lower substrate alignment control direction 8 Lower polarizing plate 9 Lower polarization Direction of plate absorption axis 10 Liquid crystal display device

Claims (9)

A (meth) acrylic resin, a compound represented by the following general formula (1), a polymer containing a repeating unit derived from a monomer represented by the following general formula (2), represented by the following general formula (3) And a polarizing plate protective film containing at least one selected from a compound represented by the following general formula (III):
The polymer containing the repeating unit derived from the compound represented by the following general formula (1), the monomer represented by the following general formula (2), and the following general formula with respect to 100 parts by mass of the (meth) acrylic resin. A polarizing plate protective film comprising 1 to 20 parts by mass of at least one selected from the compound represented by (3) and the compound represented by the following general formula (III).
General formula (1)

(In general formula (1), R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aromatic group. R ⁶ , R ⁷ and R ⁸ are each (It may have a substituent.)
General formula (2)

(In the general formula (2), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ² represents a substituent. (A) is necessary to form a 5- or 6-membered ring. Represents an atomic group, and n represents an integer of 0 to 4.)
General formula (3)
X ³ -L- (R ³ ) _m
(In the general formula (3), X ³ represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher linking group, R ³ represents a hydrogen atom, and a carbon number of 6 to 30. An alkyl group having 6 to 30 carbon atoms, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heterocyclic group having 6 to 30 ring members, and further having a substituent. M is 1 when L is a single bond, and m is (valence of L-1) when L is a divalent or higher linking group.
Formula (III)

(In General Formula (III), R ¹¹ represents a substituent, R ¹² represents a substituent represented by the following General Formula (III-1), n1 represents an integer of 0 to 4, and n1 is 2 or more. In this case, the plurality of R ¹¹ may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, the plurality of R ¹² are the same or different from each other. (However, the sum of n1 and n2 is an integer of 1 to 5.)
Formula (III-1)

(In General Formula (III-1), A ¹¹ represents a substituted or unsubstituted aromatic ring, and R ¹³ and R ¹⁴ are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula: Represents a group represented by (III-2), R ¹⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, X ¹ represents a substituted or unsubstituted monovalent aromatic ring, and n3 represents Represents an integer of 0 to 10, and when n3 is 2 or more, the plurality of R ¹⁵ and X ¹ may be the same or different from each other.
Formula (III-2)

(In General Formula (III-2), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and X ² is a substituted or unsubstituted monovalent group. N5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and X ² may be the same or different from each other. May be.) Furthermore, 0.5-1.9 mass parts of compounds represented with the following general formula (IV) are contained with respect to 100 mass parts of compounds represented with the said general formula (III). Polarizing plate protective film.
Formula (IV)

(In the general formula (IV), R ²⁰ represents a substituted or unsubstituted alkyl group having 3 to ²⁰ carbon atoms, or a substituted or unsubstituted alkenyl group, and R ²¹ and R ²² are each independently a hydrogen atom or carbon. Represents a substituted or unsubstituted alkyl group having 1 to 6 atoms or a substituted or unsubstituted alkenyl group, and R ²¹ and R ²² may be bonded to each other to form a cyclic structure, where X is a single bond or a carbonyl group; Represents.) The polarizing plate protective film according to claim 1, wherein the organic acid represented by the general formula (3) is a carboxylic acid derivative represented by the following general formula (3 ′).
General formula (3 ')

(In the general formula (3 ′), s and t are independently 1, 2 or 3, and R ⁴ is a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, It represents an alkylsulfonyl group, an arylsulfonyl group, or a heterocyclic group, and may further have a substituent, provided that R ⁴ includes R ³ in the general formula (3). The polarizing plate protective film according to claim 1, wherein the general formula (III-1) is represented by the following general formula (III-1-1).
Formula (III-1-1)

(In the general formula ^(III-1-1), the definition of R ^13, R ^{15, X 1} is Formula (III-1) in a ^{R 13, R 15, X 1} and synonymous, n3 is 0 Represents an integer of 5.)   The polarizing plate protective film according to claim 1, wherein the compound represented by the general formula (III) contains 0.05 to 0.50 ppm of nickel on a mass basis.   The polarizing plate protective film according to claim 1, wherein the (meth) acrylic resin has a mass average molecular weight of 1,000 to 2,000,000.   The polarizing plate protective film as described in any one of Claims 1-6 whose film thickness is 20 micrometers-80 micrometers.   A polarizing plate comprising at least one polarizing plate protective film according to claim 1.   A liquid crystal display device comprising at least one polarizing plate according to claim 8.

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