TWI601971B - Protection film, film laminate, and polarizing plate - Google Patents

Description

Protective film, film laminate and polarizing plate

The present invention relates to a protective film, a film laminate, and a polarizing plate.

In recent years, liquid crystal displays used in TVs and mobile devices have become thinner, and the components used in such displays, particularly polarizing plates, have been developed with the aim of achieving ultimate thinness. In general, the polarizing plate has a configuration in which triacetyl cellulose is bonded to both surfaces of a polarizing film composed of a polyvinyl alcohol-based film which is uniaxially stretched by adsorption of iodine, and is passed through an adhesive (hereinafter) An optical film such as TAC) is used as a protective film. A hydrophilic adhesive is used to bond the TAC film to the polarizing film.

The TAC film used as a protective film has high moisture permeability or large expansion and contraction due to moisture absorption and desorption. If the polarizing plate is exposed to a high-humidity environment for a long time, especially in a high-temperature and high-humidity environment, it is known. The polarizing plate has a problem that the optical function of the polarizing plate is impaired or a physical failure due to curling and warping of the polarizing plate occurs.

In order to improve these problems, acrylics with low moisture permeability are used. The situation of film or polyester film is increasing. Further, as a method of adhering the protective film to the polarizing film, a method of using an energy ray-curable composition as an adhesive has also been used. However, in the method of adhering the protective film to the polarizing film, it is difficult to thin the protective film (for example, 40 μm or less) from the viewpoint of handleability and durability during work, and it becomes a significant Question.

In order to solve such a problem, Patent Document 1 proposes a method of forming a protective film on a polarizing film by applying an uncured free radiation curing resin on a substrate film or a substrate film on which a release layer is formed. (Energy Curing Resin) After bonding the polarizing film to the coated surface, the cured resin is cured and the substrate film is peeled off.

Further, Patent Document 2 discloses a technique for achieving film formation by forming a functional layer and an adhesive layer on a base film having a release layer formed on both surfaces thereof, and then adhering to a polarizing film. Further, Patent Document 3 describes a method of forming a protective film for protecting a polarizing film with a film thickness of 40 μm or less, which is cured by applying an energy ray-curable resin directly to the polarizing film.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-163082

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2012-27260

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2014-010311

[Summary of the Invention]

However, since the protective film is formed into a film shape, the moisture becomes more likely to penetrate, and the moisture permeability tends to be high, and the polarizing plate bonded to the protective film is likely to be moisture-absorbent and dehumidified. Further, when the protective film which is not self-supporting, that is, the protective film itself cannot maintain its shape, the expansion and contraction of the polarizing film caused by moisture absorption and dewetting cannot be suppressed. As a result, there is a problem in that the polarizing film is cracked or the polarizing film and the protective film are peeled off, and the function of the polarizing plate cannot be exhibited.

In any of the above patent documents, there is no concern about such a problem, and the adhesive film and the adhesive line-forming energy ray-curing film forming a protective film together with a detailed description of the moisture permeability, and no independent protection of self-standing property. The description of the film does not solve the above problem.

In view of the above problems, an object of the present invention is to provide a protective film which has low moisture permeability and self-standing property in a thin layer state.

The present inventors have intensively studied the above-mentioned problems, and as a result, it has been found that, in view of the protective film material, attention has been paid to a urethane (meth) acrylate monomer which has hitherto been hardly noticed, and has been obtained from a plurality of kinds. A protective film obtained by a saturated cyclic aliphatic urethane (meth) acrylate monomer having a low moisture permeability and a self-standing property in a thin layer state.

The present invention encompasses the following aspects.

<1> A protective film formed by a repeating unit having a structure derived from a bifunctional urethane (meth) acrylate, The repeating unit has a plurality of saturated cyclic aliphatic groups.

<2> The protective film according to <1>, which comprises a copolymer comprising the repeating unit and block B, the repeating unit being a block A comprising a saturated ring The aliphatic group is derived from a structure of a bifunctional (meth) acrylate.

<3> The protective film according to <1> or <2>, which comprises a polymer chain composed of a plurality of the repeating units, at least in the polymer chain or at the end of the polymer chain A structure having a thioether bond.

The protective film according to any one of <1> to <3> wherein the repeating unit comprises: the following structure A comprising a saturated cyclic aliphatic group R ¹ and a saturated cyclic aliphatic group R The following structure C of ³ , -CO-NH-R ¹ -NH-CO-. . . (Structure A)

-OR ³ -O-. . . (Structure C).

<5> The protective film according to <4>, wherein the repeating unit further comprises: the following structure B comprising a saturated aliphatic chain R ² , -OR ² -CO-. . . (Structure B).

<6> The protective film of <5>, wherein the repeating unit is a structure represented by the following formula (1),

In the formula (1), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; An aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s are The sum is 1~2; x means an integer from 0~3.

<7> The protective film of <4>, wherein the repeating unit is a structure represented by the following formula (2),

In the formula (2), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and n represents an integer of 0 to 2; x represents an integer from 0 to 3.

<8> The protective film of <5>, wherein the repeating unit is a structure represented by the following formula (3),

In the formula (3), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; An aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s are The sum is 1~2; x means an integer from 0~3.

<9> The protective film of <4>, wherein the repeating unit is a structure represented by the following formula (4),

In the formula (4), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and n represents an integer of 0 to 2; x represents an integer from 0 to 3.

<10> The protective film according to any one of <4> to <9> wherein R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ³ is a dimethylene group; A tricyclodecane ring.

<11> The protective film of <2>, wherein the block B is a structure represented by the following formula (5),

In the formula (5), R ⁶ represents a saturated cyclic aliphatic group; R ⁷ represents a hydrogen atom or a methyl group; and y and z represent an integer of 0 to 2.

<12> The protective film according to <11>, wherein the R ⁶ is a tricyclodecane ring.

<13> The protective film of <3>, wherein the structure having a thioether bond is a structure represented by the following formula (6).

In the formula (6), R ⁸ represents an alkyl chain having 1 or 2 carbon atoms which may be substituted by a methyl group; X each independently represents -S- or -SH; and n represents an integer of 1 to 4.

<14> The protective film of <3>, wherein the structure having a thioether bond is a structure represented by the following formula (7).

In the formula (7), R ⁹ represents an alkyl chain having a carbon number of 1 or 2 in which a hydrogen atom may be substituted by an alkyl group; X each independently represents -S- or -SH; and R ¹⁰ represents a hydrogen atom or a methyl group; Indicates an integer from 1 to 3.

<15> The protective film according to any one of <1> to <14, wherein the moisture permeability is 150 g/(m ² .24 hours) or less, and the tensile elastic modulus is 1500 MPa or more, or the tensile strength is 25 MPa. the above.

<16> The film laminate according to any one of <1> to <15>, wherein at least one of the following (1) to (4) is provided on the protective film, (1) a film substrate supporting the protective film, (2) a hard coat layer having scratch resistance, (3) an antiglare layer for scattering light, and (4) a high refractive index layer provided on the protective film, and An antireflection layer composed of a low refractive index layer provided in the high refractive index layer.

<17> A polarizing plate comprising a protective film according to any one of <1> to <15> on at least one surface of the polarizing film.

In the protective film of the present invention, even if the thin layer is low in moisture permeability, the polarizing film to which the protective film is bonded is not easily absorbed by the polarizing film and the stretching of the polarizing film even in a high-temperature and high-humidity environment. Suppressed.

[Formation of the Invention]

Hereinafter, the protective film, the film laminate, and the polarizing plate of the present invention will be described, but the present invention is not construed as being limited to the following description.

Protective Film

The protective film of the present invention is formed by a repeating unit having a structure derived from a urethane (meth) acrylate which is a monomer, and the above repeating unit has a plurality of saturated cyclic aliphatic groups. . That is, in the protective film, a matrix forming a polymer is formed by a repeating unit having a structure derived from a urethane (meth) acrylate.

The protective film of the present invention is composed of at least the above-mentioned repeating unit, and substantially distinguishes the basic configuration of the composition, and has the following aspects: (1) the above-mentioned repeating unit-based aspect, and (2) the above-mentioned repeating unit. a block A, which is mainly a copolymer with other block B, (3) a polymer chain mainly composed of the above repeating units, or a copolymer of the above block A and block B The structure containing a thioether bond (hereinafter, abbreviated as "thioether structure" as appropriate) is included. First, the basic configuration of (1) will be described, and the description will be made in the order of (2) and (3).

The protective film of the present invention is formed by a repeating unit having a structure derived from a bifunctional urethane (meth) acrylate, and the above repeating unit has a plurality of saturated cyclic aliphatic groups. which is, In the protective film, a matrix forming a polymer is formed by a repeating unit having a structure derived from a urethane (meth) acrylate.

The above-mentioned structure derived from a urethane (meth) acrylate means that it is a urethane (meth) acrylate monomer unit, that is, a urethane which is a monomer ( In the methyl acrylate, the structure in which the double bond of the (meth) acrylate group has been cleaved is bifunctional due to the cleavage of the double bond having a (meth) acrylate group at both terminals.

The above repeating unit has a urethane bond (-NH-CO-O-). The number of the urethane bonds is not particularly limited and is, for example, from 1 to 8. The urethane bond is a polar group, and the urethane bonds in each repeating unit are close to each other by an intermolecular force. On the other hand, the saturated cyclic aliphatic group is a non-polar cyclic structure and has a high molecular weight. It is considered that the high molecular weight of the saturated cyclic aliphatic group acts due to the intermolecular interaction between the urethane bonds, and the above-mentioned intermolecular force produces high cohesive force. As a result, the protective film composed of the above repeating unit has self-standing property and also has low moisture permeability in a thin layer state.

The above urethane (meth) acrylate monomer unit has a plurality of saturated cyclic aliphatic groups. The saturated cyclic aliphatic group is not particularly limited, and from the viewpoint of enhancing the cohesive force due to the molecular weight, a saturated cyclic aliphatic group having a five-membered or more ring is preferable. The upper limit of the number of the members is not particularly limited. From the viewpoint of easiness of synthesis of the monomer which is a raw material for protecting the film, for example, it is 15 or less members, preferably 10 or less members. The above-mentioned so-called ring number, when the saturated cyclic aliphatic group has In the case of a plurality of cyclic structures, the number of members of the ring having the largest cyclic structure is defined; and when the saturated cyclic aliphatic group has a double or three ring, it means a ring structure other than carbon bonded to the bridge of the bridgehead carbon. Number of rings. For example, when it is a tricyclodecane ring, the number of members is 9.

The main chain of the cyclic structure of the saturated cyclic aliphatic group may be formed only by a carbon atom, or may be formed outside the carbon atom, and by an oxygen atom and/or a nitrogen atom. Further, a linear or/or branched structure having a carbon number of 1 to 10 may be added to the carbon atom of the cyclic structure.

Examples of the saturated cyclic aliphatic group include a 3,5,5-trimethylcyclohexane ring, a tricyclodecane ring, and an adamantane ring. The saturated cyclic aliphatic group may be bonded to a urethane bond group by a saturated aliphatic chain, and the rigidity of the repeating unit can be appropriately adjusted by changing the carbon number of the saturated aliphatic chain. In the case of a saturated aliphatic chain, there are a linear structure and a branched structure. As an example of a linear structure, -(CH ₂ ) _n - (n is an integer of 1 to 10); From the viewpoint of lowering the flexibility and increasing the rigidity, it is preferably -(CH ₂ )- or -(CH ₂ ) ₂ -. On the other hand, as the branched structure, a structure in which hydrogen on at least one carbon of the linear structure is substituted with a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or the like can be exemplified.

When the above 3,5,5-trimethylcyclohexane ring is bonded to two urethane bonds through a methylene chain, 3-methylene-3,5,5-trimethyl The cyclohexane ring is bonded to each of the urethane bonds; when the tricyclodecane ring is bonded to the two urethane bonds through the methylene chain, the dimethylene tricyclic oxime The alkane ring is bonded to each urethane bond.

The 3-methylene-3,5,5-trimethylcyclohexane ring and the dimethylene tricyclodecane ring are preferably a ring structure, and the polymer chain contains the The protective film of the ring structure suitably exhibits low moisture permeability and self-standing property.

In addition to the saturated cyclic aliphatic group, the main chain of the repeating unit preferably contains a saturated aliphatic chain having 5 to 10 carbon atoms. Since the saturated aliphatic chain has a carbon number of 5 or more, the saturated aliphatic chain having a long chain length and flexibility imparts flexibility to the repeating unit, and the brittleness of the protective film is reduced. On the other hand, since the carbon number is 10 or less, an increase in the moisture permeability in the protective film can be suppressed. The saturated aliphatic chain may have a linear structure or a branched structure. The saturated aliphatic chain described above, for example, constitutes a part of a repeating unit by a structure in which a urethane bond or an ester bond is transmitted.

Examples of the linear structure include -(CH ₂ ) _n1 - (n1 is an integer of 5 to 10), and particularly preferably -(CH ₂ ) ₅ -. On the other hand, as the branched structure, a structure in which hydrogen on at least one carbon of the linear structure is substituted with a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or the like can be exemplified.

As an example of the repeating unit can be exemplified comprising: a saturated cyclic aliphatic group R ¹ of the following structure A, and structure-containing cyclic saturated aliphatic group R of the following structure C ^3.

-CO-NH-R ¹ -NH-CO-. . . (Structure A)

-OR ³ -O-. . . (Structure C)

The repeating unit can be obtained, for example, from a diisocyanate containing R ¹ , a diol containing R ³ , and a urethane (meth) acrylate obtained by (meth) acrylate, which can be easily Manufacturing. As an example, the ratio of the structure A and the structure C may be m+1:m or m:m+1, and the above m represents an integer of 1 to 4.

Further, the repeating unit may further include the following structure B containing a saturated aliphatic chain R ² .

-OR ² -CO-. . . (Structure B)

As the repeating unit, for example, a diisocyanate containing R ¹ , an ester containing R ² (optionally used), a diol containing R ³ , and (meth) acrylate or having (meth) acrylonitrile may be used. It is obtained from a base isocyanate and can be easily produced. As an example, the ratio of the structure A, the structure B, and the structure C may be m+1: m (r + s): m, m + 1 : k + n: m, m: m (r + s): m +1, m:k+n:m+1. The above m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and the sum of r and s is 1 to 2; k represents an integer of 0 to 2; and n represents an integer of 0 to 2.

Specific examples of the above repeating unit having a saturated cyclic aliphatic group and a saturated aliphatic chain are shown below. As shown in the general formula (1), the structure derived from (meth) acrylate (meth) acrylate structure H ₂ C=CH-CO ₂ - (or H ₂ C=C(CH ₃ )- The carbon-carbon double bond of CO ₂ -) is broken into a single bond structure.

(In the formula (1), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having a carbon number of 5 to 10; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group, R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s The sum is 1~2; x means the integer from 0~3)

Since m in the above formula (1) is an integer of 1 to 4, the moisture permeability of the protective film can be further reduced, and the tensile modulus and tensile strength can be further improved. m is preferably 1 or 2, more preferably 1. The same applies to the following general formulae (2), (3) and (4).

A suitable structure is shown below: in the above formula (1), R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ² is -(CH ₂ ) ₅ -; R ³ is a dimethylene tricyclodecane ring; R ⁴ and R ⁵ are a hydrogen atom; r and s are 1; and x is 1.

Other specific examples of the repeating unit are shown below.

(In the formula (2), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and represents an integer of 0 to 2; ;x represents an integer from 0 to 3)

A suitable repeating unit is shown below: in the above formula (2), R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ² is -(CH ₂ ) ₅ - ; R ³ is a dimethylene tricyclodecane ring; R ⁴ and R ⁵ are a hydrogen atom; k and n are 1.

Further, other specific examples of the repeating unit are shown below.

(In the formula (3), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s The sum is 1~2; x means the integer from 0~3)

A suitable repeating unit is shown below: in the above formula (3), R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ² is -(CH ₂ ) ₅ - R ³ is a dimethylene tricyclodecane ring; R ⁴ and R ⁵ are a hydrogen atom; r and s are 1; and x is 1.

Other specific examples of the repeating unit are shown below.

(In the formula (4), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and represents an integer of 0 to 2; ;x represents an integer from 0 to 3)

A suitable repeating unit is shown below: in the above formula (4), R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ² is -(CH ₂ ) ₅ - ; R ³ is a dimethylene tricyclodecane ring; R ⁴ and R ⁵ are a hydrogen atom; k and n are 1.

Further, the isomers of the structures represented by the above formula (1a), formula (2a), formula (3a) and formula (4a) are also included in the repeating unit of the present invention.

Next, the form of the copolymer in the protective film of the present invention will be described. The protective film of the present embodiment is composed of a copolymer comprising the above repeating unit and block B; the repeating unit is a block A containing a source having one saturated cyclic aliphatic group. A structure of a bifunctional (meth) acrylate. In other words, the protective film of the copolymer can be said to comprise a copolymer containing a block A (repeating unit) and a block B; the block A (repeating unit) contains a plurality of saturated cyclic aliphatic groups. A bifunctional urethane (meth) acrylate monomer unit containing a bifunctional (meth) acrylate monomer unit having one saturated cyclic aliphatic group .

In the case of the repeating unit of block A, it is as described above. Block B is a bifunctional (meth) acrylate monomer unit having one saturated cyclic aliphatic group. The block B contains a (meth) acrylate monomer unit and does not contain a urethane bond. The block A-derived acrylate moiety is bonded to other block A or to the block B-derived acrylate-derived moiety (-block A-block A-, or -block A-embedded) Paragraph B-).

-CO-O- in the (meth) acrylate moiety of block B is more linear than the non-linear structure -CO-NH- of the urethane (meth) acrylate moiety, and the flexibility low. Further, since the block B has only one saturated cyclic aliphatic group, it has a more linear structure than the block A and has high rigidity. The protective film containing the copolymer containing only the block A has low moisture permeability and self-standing property even in a thin layer state, and by using the block B having high rigidity to improve the self-supporting property, it is possible to provide a suppressable cause. A protective film for stretching and contracting a polarizing film for moisture absorption and desorption.

The above bifunctional (meth) acrylate monomer unit of the block B has one saturated cyclic aliphatic group. The saturated cyclic aliphatic group is not particularly limited, and from the viewpoint of obtaining a moisture permeability reducing effect due to molecular weight, a saturated cyclic aliphatic group having a five-membered or more ring is preferable. The upper limit of the number of members is not particularly limited, and from the viewpoint of easiness of synthesis of the monomer to be the raw material of the block B, for example, it is 15 or less members, preferably 10 or less members. The above-mentioned so-called ring number, when the saturated cyclic aliphatic group has a complex cyclic structure, represents the number of members of the largest cyclic structure; and when the saturated cyclic aliphatic group has a double or three ring, it means that in addition to the link The number of rings of the ring structure other than carbon of the carbon bridge of the bridgehead. For example, when it is a tricyclodecane ring, the number of members is 9.

The main chain of the cyclic structure of a saturated cyclic aliphatic group can be borrowed only It is formed by a carbon atom, and may be formed by an oxygen atom and/or a nitrogen atom in addition to a carbon atom. Further, a linear or/or branched structure having a carbon number of 1 to 10 may be added to the carbon atom of the cyclic structure.

Examples of the saturated cyclic aliphatic group include a tricyclodecane ring, a 3,5,5-trimethylcyclohexane ring, and an adamantane ring. The saturated cyclic aliphatic group can also be bonded to a saturated aliphatic chain by a structure derived from a (meth) acrylate, and the rigidity of the repeating unit can be appropriately adjusted by changing the carbon number of the saturated aliphatic chain. In the case of a saturated aliphatic chain, there are a linear structure and a branched structure, and as an example of a linear structure, -(CH ₂ ) _n - (n is an integer of 1 to 10); From the viewpoint of lowering the flexibility and increasing the rigidity, it is particularly preferred that -(CH ₂ )- or -(CH ₂ ) ₂ -. Further, when the block B is a structure having no linear structure, the rigidity is also improved (the above n is 0). On the other hand, as the branched structure, a structure in which hydrogen on at least one carbon of the linear structure is substituted with a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or the like can be exemplified.

When the above 3,5,5-trimethylcyclohexane ring is bonded to two (meth) acrylate-derived structures through a methylene chain, it becomes 3-methylene-3,5. a 5-trimethylcyclohexane ring bonded to a structure derived from each (meth) acrylate; and a tricyclodecane ring system transmitted through a methylene chain and two (meth) acrylate-derived Upon structural bonding, the dimethylene tricyclodecane ring is bonded to the structure derived from each (meth) acrylate.

The above-mentioned dimethylene tricyclodecane ring-based preferred ring structure suitably exhibits low moisture permeability and self-standing property in the protective film containing the ring structure in the polymer chain.

Specific examples of the block B having the above saturated cyclic aliphatic group and saturated aliphatic chain are shown below. Block B has a structure derived from (meth) acrylate at both ends, and the structure derived from (meth) acrylate is bonded to other block B or block A (-block B-block) B- or - block B-block A-). As shown in the general formula (5), the acrylate-derived moiety is a structure in which a carbon-carbon double bond of an acrylate structure H ₂ C=HC-CO ₂ - is broken to form a single bond (methacrylate). The structure is the same).

(In the formula (5), R ⁶ represents a saturated cyclic aliphatic group; R ⁷ represents a hydrogen atom or a methyl group; and y and z represent an integer of 0 to 2)

A suitable structure is shown below. In the above formula (5), R ⁶ is a tricyclodecane ring; R ⁷ is a hydrogen atom, and y and z are 1.

The weight ratio of the block A to the block B in the copolymer is not particularly limited, but in order to make the degree of tensile modulus of the protective film resulting from the block B suitable, the block A: block B = 70:30~15:85 is better, 60:40~15:85 is better, 50:50~15:85 is especially good.

Further, the ratio of the copolymer in the protective film of the present invention is preferably from a viewpoint of lowering the moisture permeability of the protective film and improving the self-supporting property, and is preferably 70% by mass or more and 99.5 by mass based on the total mass of the protective film. % or less is preferably 80% by mass or more and 99.5% by mass or less.

Next, the structure of the thioether will be described. The thioether structure has a thioether bond and has at least an -S-R structure (R is a hydrocarbon). a single bond on the opposite side of R to the thioether structure, bonded to the structure of the repeating unit derived from (meth) acrylate, and in the -S- of the thioether bond, and the urethane in the repeating unit Hydrogen bonding occurs between the bonds, which improves the self-supporting properties of the protective film.

The thioether structure may have at least one thioether bond (-S-). However, since a strong hydrogen bond is generated by including a plurality of thioether bonds, the self-supporting property of the protective film is further improved.

The hydrocarbon R of the thioether structure has a cyclic structure and/or a chain structure. The main chain of the above cyclic structure and chain structure may be formed only by carbon atoms, or may be formed by carbon atoms and/or nitrogen atoms in addition to carbon atoms. As the ring structure, for example, 1, 2, 3 - 3 can be exemplified Ring, 1, 2, 4-three Ring, 1,3,5-three The ring, the maleimide ring, and the like; as the chain structure, an alkyl chain represented by -(CH ₂ ) _n2 - (n2 is an integer of 1 to 10) can be exemplified. The hydrogen atom bonded to the carbon atom and/or the nitrogen atom constituting the main chain of the cyclic structure and the chain structure may be substituted with a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or the like.

Further, the thioether structure may have a substituent, and examples thereof include a carbonyl group, a carboxyl group, an amine group, a decylamino group, and a hydroxyl group.

The thioether structure is bonded to (1) a polymer chain composed of a plurality of repeating units, or (2) a terminal of the above polymer chain. In the case of (1), the thioether structure has a plurality of thioether bonds, and one thioether bond is bonded to the structure in which the repeating unit is derived from (meth) acrylate, and the other thioether bond is bonded to other repeats. The unit is derived from the structure of the (meth) acrylate. The following shows that the repeating unit has a portion derived from an acrylate. In the case of (1) the bonding state. Further, when the thioether structure has 3 or more -S-, it is bonded to a plurality of repeating units.

On the other hand, in the case of (2), a thioether structure is bonded to the terminal of the polymer chain, and the thioether structure is bonded to one repeating unit. The bonding state of (2) when the repeating unit has a condition derived from the acrylate portion is shown below.

The above R represents a hydrocarbon.

The bonding state of the above repeating unit and the thioether structure is as described above, but when the polymer chain is formed by repeating units (block A) and block B, the (1') thioether structure can be bonded to Block A and block B; may also be bonded to block A and other block A; may also bond to block B and other block B. Also, the (2') thioether structure can be bonded to the block A without being bonded to the other block A or block B; it can also be bonded to the block B without bonding to the block A. Or other block B.

The thioether structure having one or a plurality of thioether bonds has been described above, and specific examples of the thioether structure having both a cyclic structure and a chain structure are shown below.

(In the formula (6), R ⁸ represents an alkyl chain having 1 or 2 carbon atoms which may be substituted by a methyl group; X each independently represents -S- or -SH; n represents an integer of 1 to 4)

In the above formula (6), specific examples of R ⁸ include -(CH ₂ )- and -(CH ₂ ) ₂ -, and the hydrogen atom of the alkyl chain may be methyl, ethyl or propyl. Substituents such as substituents are substituted.

X is -S- or -SH: 2 structures in which X is -S- are represented by the following formula (6a); wherein one X is -S- and the other X is -SH is a structure (6b); two structures in which X is -SH are represented by the following formula (6c). The -S-line of the thioether structure and the repeating unit are derived from the structural bonding of the (meth) acrylate.

Further, specific examples of the thioether structure having a chain structure are shown below.

(In the formula (7), R ⁹ represents an alkyl chain having a carbon number of 1 or 2 in which a hydrogen atom may be substituted with an alkyl group; X each independently represents -S- or -SH; and R ¹⁰ represents a hydrogen atom or a methyl group; p represents an integer from 1 to 3)

In the above formula (7), as a specific example of R ⁹ , an alkyl chain of -(CH ₂ )- or -(CH ₂ ) ₂ - may be mentioned, and a hydrogen atom of the above alkyl chain may be via a methyl group or a Substituents such as a group or a propyl group are substituted.

In the formula (7), among the structures in which p is 3: three structures in which X is -S- are represented by the following formula (7a); two X are -S- and the other X is - The structure of SH is represented by the following general formula (7b); one structure in which X is -S- and the other two X is -SH is represented by the following general formula (7c); three structures in which X is -SH It is represented by the following general formula (7d). The -S-line of the thioether structure is bonded to the structure of the repeating unit derived from (meth) acrylate.

In particular, the thioether structure represented by the above formula (7d) is tetrafunctional, and since the complex three-dimensional structure is formed with the repeating unit, the obtained protective film has high tensile strength and can improve self-standing property.

In the protective film, the above repeating unit and thioether structure The weight ratio is not particularly limited, but in order to make the value of the tensile strength of the protective film derived from the thioether structure suitable, the repeating unit: thioether structure = 95:5 to 50:50 is preferable, 95:5~ 80:20 is better, 90:10~70:30 is especially good.

Further, when the protective film is composed of a copolymer, the total amount of the repeating unit (block A) and the block B, and the weight ratio of the thioether structure are the total of the repeating unit (block A) and the block B. Amount: thioether structure = 95: 5 ~ 50: 50 is better, 95: 5 ~ 80: 20 is better, 90: 10 ~ 70: 30 is particularly good.

Moreover, the ratio of the polymer chain (the total ratio of the repeating unit (block A), the block B, and the thioether structure) in the protective film of the present invention is lowered from the viewpoint of lowering the moisture permeability of the protective film and improving the self-standing property. In view of the above, it is preferably 70% by mass or more and 99.5% by mass or less, and preferably 80% by mass or more and 99.5% by mass or less based on the total mass of the protective film.

The protective film of the present invention is formed by what kind of polymer chain (repeating unit (block A), block B and thioether structure), and can be passed through thermal decomposition GC-MS and FT-IR. Judging by analyzing the protective film. In particular, thermal decomposition of GC-MS is useful because the monomer unit contained in the protective film can be detected as a monomer component.

The protective film may contain various additives such as an ultraviolet absorber, a leveling agent, and an antistatic agent, without impairing the film forming property of the protective film, the tensile modulus, the tensile strength, and the low moisture permeability. Thereby, the protective film can be provided with ultraviolet absorbing properties, peeling properties, and antistatic properties.

A known person can be used as the ultraviolet absorber, and examples thereof include 2-hydroxy-4-octyloxybenzophenone and 2-hydroxy-4-methoxy-5-sulfo group. Benzotrione series such as benzophenone; benzotriazole series such as 2-(2'-hydroxy-5-methylphenyl)benzotriazole; phenyl salicylate and salicylic acid A hindered amine system such as phenyl phenyl ester. As the leveling agent and the antistatic agent, a known one can also be used.

Since the protective film of the present invention is formed into a film shape, the upper limit of the film thickness is preferably, for example, 50 μm, preferably 30 μm. The lower limit value is not particularly limited, and is preferably 5 μm, preferably 10 μm from the viewpoint of ensuring low moisture permeability.

The moisture permeability of the protective film of the present invention is low, and in the state of a thin layer of 30 μm, it is preferably 150 g/(m ² .24 hours) or less, preferably 120 g/(m ² .24 hours) or less. The best is 100g/(m ² .24 hours) or less. The lower limit of the moisture permeability is not particularly limited, and is, for example, 15 g/(m ² .24 hours) or more.

The protective film of the present invention has self-standing properties. The term "self-supporting" means that the protective film can be held in a single object. When the tensile modulus of the protective film is 1500 MPa or more as a criterion, the protective film can be regarded as having self-standing properties. In order to suppress the expansion and contraction of the polarizing film due to moisture absorption and desorption, the tensile elastic modulus is preferably higher, specifically, 1500 MPa or more, preferably 2500 MPa or more. The upper limit is not particularly limited and is, for example, 4500 MPa.

In addition, when the tensile strength of the protective film is 15 MPa or more, the protective film may be regarded as having self-standing property. In order to suppress the expansion and contraction of the polarizing film due to moisture absorption and desorption, the tensile strength is preferably as high as possible, and is preferably 25 MPa or more. The upper limit value is not particularly limited and is, for example, 100 MPa.

Thin film laminate

Next, the film laminate will be described. The film laminate system of the present invention comprises any one of the following (1) to (4) on at least one surface of the protective film: (1) a film substrate supporting the protective film, and (2) having scratch resistance. a hard coat layer, (3) an antiglare layer that scatters light, and (4) an antireflection formed of a high refractive index layer provided on the protective film and a low refractive index layer provided in the high refractive index layer Floor. Of course, the above-mentioned thin film laminate may have any of the above (1) to (4) on both sides of the protective film. That is, it is possible to have the same layer on both sides (for example, (1) on the surface of the protective film, (1) on the back surface) or a different layer (for example, on the surface of the protective film (1), There are (2) on the back, or (2) on the surface and (3) on the back. Further, in addition to (1) to (4), other layers (1) to (4) may be provided, and a layered structure may be employed. Hereinafter, (1) to (4) will be described.

[Film substrate]

The protective film of the present invention can be integrally treated in a state of being laminated with other films. Further, when a protective film is formed on a film substrate by a coating method such as a roll coating method or a gravure coating method to produce a film laminate, the film substrate can also be directly used as a part of the film laminate. use.

The film substrate is responsible for supporting the action of the protective film, and it is preferable to have a release layer on the side of the build-up protective film because it is finally removed by peeling. Furthermore, when the film substrate passes through the release layer, it has a function In the case of the layer, after the film substrate is bonded to the functional layer side of the protective film, when the film substrate is removed and removed, the functional layer is usually transferred to the protective film side without remaining on the film substrate side.

In general, since the protective film and the polarizing film are bonded together by the ultraviolet curable adhesive, it is preferred that the film substrate does not have ultraviolet absorbing performance so as not to hinder ultraviolet irradiation. Further, in the various manufacturing steps of processing the display film to the display device, the optical properties are inspected in various manufacturing steps of the display device, so that the polarizing film and the protective film which are basic components of the polarizing plate can be affected in optical property measurement. To minimize the film substrate, the film substrate preferably has transparency. From such a viewpoint, it is preferred to use a polyester film substrate having a release layer as a film substrate.

The polyester film substrate may have a release layer as described above, and may further form other functional layers in addition to the release layer. Examples of the functional layer include a hard coat layer (HC layer), an antiglare layer (AG layer), and an antireflection layer (LR layer). The layers are formed on the release layer of the polyester film, and after being laminated on the protective film, the polyester substrate is peeled off from the release layer, and the film laminate having the respective functional layers and the protective film can be easily obtained. .

[hard coating]

The hard coat layer has a hard coat property. In the present invention, the hard coat performance is based on JIS K5600:1999, and the scratch hardness by the pencil method is 2H or more under the conditions of a load of 500 g and a speed of 1 mm/s.

The resin component constituting the hard coat layer is suitable because the free radiation curable resin can be efficiently cured by a simple processing operation. The radiation-hardening type which imparts a film having sufficient strength and transparency after hardening can be used without particular limitation. Resin.

As the radical radiation-curable resin, the following may be used singly or a composition in which an acrylonitrile group, a methacryl oxime group, a propylene fluorenyl group, a methacryloxy group or a methacryloxy group are appropriately mixed may be used. A radically polymerizable functional group, or a monomer, oligomer, prepolymer or polymer of a cationically polymerizable functional group such as an epoxy group, a vinyl ether group or an oxethone group. Examples of the monomer include methyl acrylate, methyl methacrylate, methoxypolyethylene methacrylate, cyclohexyl methacrylate, phenoxyethyl methacrylate, and ethylene glycol. Methacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, neopentyl alcohol triacrylate, and the like. Examples of the oligomer and the prepolymer include polyester acrylate, polyurethane acrylate, polyfunctional urethane acrylate, epoxy acrylate, polyether acrylate, and alkyd acrylate. Acrylate compound such as melamine acrylate or fluorenone acrylate; unsaturated polyester, tetramethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, bisphenol A condensed water Glycidyl ether and various epoxy compounds such as alicyclic epoxy groups; 3-ethyl-3-hydroxymethyloxetane, 1,4-bis{[(3-ethyl-3-oxocycle) An oxetane compound such as butanyl)methoxy]methyl}benzene or bis[1-ethyl(3-oxetanyl)methyl ether. The polymer may, for example, be a polyacrylate, a polyurethane acrylate or a polyester acrylate. These can be used alone or in combination. In the above-mentioned free radiation curable resin, in particular, a polyfunctional monomer having three or more functional groups can increase the curing rate or increase the hardness of the cured product. Further, by using a polyfunctional urethane C The enoate can impart hardness and flexibility to the cured product.

The free-radiation-curable resin can be directly cured by irradiation with free radiation, but when it is hardened by ultraviolet irradiation, it is necessary to add a photopolymerization initiator. As a photopolymerization initiator, the following initiators can be used singly or in combination: free radicals such as acetophenone, benzophenone, thioxanthone, benzoin, benzoin methyl ether A polymerization initiator; a cationic polymerization initiator such as an aromatic diazonium salt, an aromatic onium salt, an aromatic onium salt or a metallocene compound.

The film thickness of the hard coat layer is not particularly limited as long as it exhibits hard coat properties, and is generally 2 μm or more and 10 μm or less.

In order to impart functions other than the hard coat property, various additives can be added to the above hard coat layer. As an example, a fluorine-based or fluorenone-based leveling agent added to improve the release property from the peeling of the polyester film substrate may be used as appropriate for the following functions. Or an electron conjugate system, a metal oxide system, or an ion-based antistatic agent added to prevent adhesion of dust due to peeling and charging during peeling. Regarding the aspect in which the additive can be used, the following antiglare layer and low refractive index layer are also the same.

[anti-glare layer]

The anti-glare layer has an anti-glare function for scattering light, and an anti-glare function is realized by an external haze value and/or an internal haze value; the anti-glare layer has irregularities formed on the surface, or contains light-transmitting fine particles inside, Or both.

The method of forming the unevenness on the surface of the anti-glare layer is not particularly limited, but the method of coating the free radiation-curable resin on the polyester film substrate on which the irregularities have been formed and hardening after coating is easy to control the concave The convex shape is preferred.

The shape of the surface unevenness on the side of the polyester substrate on the antiglare layer is determined by the required antiglare property. A more suitable uneven shape can be defined by the roughness parameter Ra, and is preferably Ra: 0.01 μm or more, Sm: 50 μm to 500 μm, and an average tilt angle: 0.1° to 3.0°.

The thickness of the anti-glare layer is not particularly limited, but if it is too thin, the shape of the concavities and convexities formed on the side of the support body also remains on the unevenness formed on the side of the carrier, thereby preventing glare. Words are not good. On the other hand, when it is too thick, curling and cracking due to curing shrinkage of the resin may occur, and the treatment is not preferable, so it is preferably in the range of 1 to 12 μm.

On the other hand, as the light-transmitting fine particles added to the radical ray-curable resin, for example, an acrylic resin, a polystyrene resin, a styrene-acrylic copolymer, a nylon resin, or a ruthenium can be used in order to generate an internal haze value. An organic resin fine particle such as a ketone resin, a melamine resin or a polyether oxime resin; or an inorganic fine particle such as cerium oxide. Here, it is suitable that the difference in refractive index between the light-transmitting fine particles and the resin component is 0.04 or less, and more preferably 0.01 or less. If the refractive index difference from the resin component is large, internal scattering occurs in the antiglare layer, and the contrast becomes lower, which is not preferable.

When the anti-glare property is exhibited, the film thickness of the anti-glare layer is not particularly limited, and is generally 2 μm or more and 10 μm or less. Further, the antiglare layer may have a hard coat property in addition to the antiglare property, and in this case, the hard coat property is imparted by adjusting the resin component to be used.

[anti-reflection layer]

The antireflection layer is composed of a low refractive index layer and a high refractive index layer. The low refractive index layer is a layer having a refractive index lower than that of the adjacent high refractive index layer (hard coat layer, antiglare layer or protective film), and helps to prevent from low in a state of being laminated with a high refractive index layer. Reflection of light on the side of the refractive index layer. Here, the high refractive index and the low refractive index are not intended to define an absolute refractive index, but it is defined that the refractive indices of the two layers are relatively high or low, and when the relationship between the two has a relationship of the following formula 1 , as the reflectivity will become the lowest.

N2=(n1) ^1/2 . . . (Formula 1)

(n1 is the refractive index of the high refractive index layer, and n2 is the refractive index of the low refractive index layer)

In order to suitably exhibit the antireflection function, the refractive index of the low refractive index layer is preferably 1.45 or less. Examples of the material having such characteristics include LiF (refractive index n = 1.4), MgF ₂ (n = 1.4), and 3NaF. Inorganic materials such as AlF ₃ (n = 1.4), AlF ₃ (n = 1.4), and Na ₃ AlF ₆ (n = 1.33) are microparticulated, and inorganic low-reflection contained in an acrylic resin or an epoxy resin is used. Materials; organic low-reflection materials such as fluorine-based, anthrone-based organic compounds, thermoplastic resins, thermosetting resins, and radiation-curable resins. Among them, in particular, since the fluorine-based fluorine-containing material is excellent in antifouling property, it is preferable that the low refractive index layer is prevented from being stained on the surface.

The fluorine-containing material may be a vinylidene fluoride-based copolymer which is dissolved in an organic solvent and which is easy to handle, or a fluoroolefin/hydrocarbon copolymer, a fluorine-containing epoxy resin, a fluorine-containing epoxy acrylate, or a fluorine-containing fluorene. A ketone, a fluorine-containing alkoxysilane, a fluorine-containing polyoxyalkylene or the like. These may be used alone or in combination. The fluorine-containing polyoxyalkylene system contains at least a hydrolyzable decane compound The mixture and/or the mixture of the hydrolyzate and the hardening accelerator are cured; and the hydrolyzable decane compound may also contain a cationically modified decane compound having a function as a film forming agent and an antistatic agent.

When the antireflection function is exhibited in relation to the high refractive index layer, the film thickness of the low refractive index layer is not particularly limited, and is generally 0.05 μm or more and 0.2 μm or less; and the film thickness of the high refractive index layer is preferably appropriate. It is 0.05 μm or more and 10 μm or less. The low refractive index layer exhibits an antireflection function in relation to the high refractive index layer, but may have a hard coat property depending on the selected raw material. Further, the high refractive index layer may have a hard coat property depending on the selected raw material, and may further have antiglare properties.

Polarizer

Next, a polarizing plate including the protective film of the present invention will be described. The polarizing plate of the present invention includes the protective film on at least one surface of the polarizing film.

The polarizing film is made of a polyvinyl alcohol-based resin (PVA resin), and is a film having a property of penetrating light having a vibrational surface in a certain direction among the light incident on the polarizing film, and absorbing it perpendicular thereto. The light of the vibrating surface; typically, there is a dichroic pigment in the PVA resin adsorption alignment. The PVA resin constituting the polarizing film is obtained by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate-based resin which is a raw material of the PVA resin may be a copolymer of vinyl acetate and other monomers copolymerizable therewith, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate. The polarizing film can be produced by applying uniaxial stretching, dyeing by a dichroic dye, and boric acid crosslinking treatment to a film made of the PVA resin. As a dichroic pigment, Use iodine and dichroic organic dyes. The uniaxial stretching may be performed before the dyeing by the dichroic dye, or simultaneously with the dyeing by the dichroic dye, or after the dyeing by the dichroic dye, for example, The boric acid cross-linking treatment is carried out. The polarizing film which consists of a PVA resin which adsorb|distributes the dichroic dye which can be manufactured by this, is one of the constituent materials of a polarizing plate.

For the bonding of the polarizing film and the protective film, an ultraviolet curing adhesive is preferably used. The ultraviolet curable adhesive can be used as long as it can be supplied in a liquid form, and a known ultraviolet curable adhesive which has been conventionally used for the production of a polarizing plate can be used. From the viewpoints of weather resistance and polymerizability, it is preferred. A cationically polymerizable compound (for example, an epoxy compound) is one of ultraviolet curable components.

In the ultraviolet curing type adhesive, in addition to the cationically polymerizable compound represented by an epoxy compound, a polymerization initiator may be blended, in particular, a photocationic polymerization initiator may be blended, which is used to The irradiation of ultraviolet rays generates a cationic species or a Lewis acid, and polymerization of the cationically polymerizable compound starts. Further, a thermal cationic polymerization initiator which initiates polymerization by heating may be blended, and various additives such as a photosensitizer may be blended.

The polarizing plate of the present invention comprises a protective film provided on at least one surface and a protective film on both surfaces of the polarizing plate. Since the protective film is low in moisture permeability even in a thin layer, even in a high-temperature and high-humidity environment, the polarizing film is less likely to absorb moisture and the expansion and contraction of the polarizing film is suppressed.

"Manufacturing method of protective film and film laminate"

[Protective film forming step]

When the protective film can be produced, the method for producing the protective film of the present invention is not particularly limited, and a method of forming a protective film may be included. The protective film forming step includes the following steps (A1) and (A2):

Step (A1): An energy ray-curable composition is coated on the film substrate or on the release layer of the film substrate.

Step (A2): After coating, the energy ray-curable composition is cured to form a protective film.

The energy ray-hardening composition contains a urethane (meth) acrylate as an essential component. A raw material of the above-mentioned urethane (meth) acrylate-based protective film which is a monomer is polymerized by the monomer to form a repeating unit described in the above-mentioned "protective film".

In another embodiment, the energy ray-curable composition includes a urethane (meth) acrylate which forms the repeating unit (block A) and a block B which is a raw material of the protective film. (Meth) acrylate. These monomers are copolymerized to form the copolymer described in the above "Protective Film".

Further, in another embodiment, the energy ray-curable composition includes a urethane (meth) acrylate which forms the repeating unit (block A), and a block B which is formed. (Meth) acrylate and/or thiol which forms a thioether structure. When a urethane (meth) acrylate is polymerized with each other, or a urethane (meth) acrylate is copolymerized with a (meth) acrylate to form a polymer chain, a thiol is bonded to a polymer chain. Or the end of the polymer chain, thereby forming the inclusion in the above A protective film of a polymer chain described in "Protective Film".

The urethane (meth) acrylate having a (meth) acrylate-derived structure at both ends is different from the above repeating unit in the (meth) acrylate group, but has a monomer A plurality of or a portion of a saturated cyclic aliphatic group or the like, and structures other than the two ends are common, and the same applies to the (meth) acrylate. Specific examples of the saturated cyclic aliphatic group and the saturated aliphatic chain are the same as those for the repeating unit (block A) and block B, and the description thereof will be omitted.

As an example of the above-described urethane (meth) acrylate, a structure comprising a structure A having a saturated cyclic aliphatic group R ¹ and having the following saturated aliphatic chain R ² may be exemplified. Structure B (optionally contained) and the following structure C having a saturated cyclic aliphatic group R ³ . The above structure B is an arbitrary component.

-CO-NH-R ¹ -NH-CO-. . . (Structure A)

-OR ² -CO-. . . (Structure B)

-OR ³ -O-. . . (Structure C)

The urethane (meth) acrylate may be used in addition to, for example, a diisocyanate containing R ¹ , an ester containing R ² (optionally used), a diol containing R ³ , and (methyl group). Acrylate or isocyanate having a (meth) acrylonitrile group, which can be easily produced.

As an example, the ratio of the structure A, the structure B, and the structure C may be m+1: m (r + s): m, m + 1 : k + n: m, m: m (r + s): m +1 or m: k+n: m+1. The above m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and the sum of r and s is 1 to 2; k represents an integer of 0 to 2; and n represents an integer of 0 to 2.

The method of synthesizing the urethane (meth) acrylate is not particularly limited, and as an example, a method of first synthesizing a bifunctional intermediate product and (meth) acrylate or having (meth) may be mentioned. The acryloyl isocyanate is synthesized to both ends of the intermediate product.

Specifically, a method of synthesizing a urethane (meth) acrylate corresponding to the repeating unit of the above formula (1) is exemplified as follows. [1] reacting an ester having R ² with a diol having R ³ at a molar ratio of m(r+s):m to further react a diisocyanate having m+1 molar R ¹ , An intermediate product having a -N=C=O group at both ends is obtained. [2] Thereafter, by reacting 2 mol (meth) acrylate with 1 mol of the above intermediate product, a urethane (meth) acrylate represented by the following formula (8) can be obtained. .

(In the formula (8), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having a carbon number of 5 to 10; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s The sum is 1~2; x means the integer from 0~3)

The method of synthesizing the urethane (meth) acrylate corresponding to the repeating unit of the formula (2) is exemplified as follows. [1] A diisocyanate having R ¹ is reacted with a diol having R ³ at a molar ratio of m+1:m to obtain an intermediate product having a -N=C=O group at both terminals. A urethane (methyl) corresponding to the repeating unit represented by the general formula (9) can be obtained by any one of the following [2-1], [2-2] or [2-3] Acrylate. [2-1] Thereafter, 2 mol (meth) acrylate is reacted with 1 mol of the above intermediate product; [2-2] k + n mol having R ² ester to 1 mol of the above intermediate product After the reaction, 2 mol (meth) acrylate is reacted; [2-3] (methyl) obtained by reacting an ester of R ² having R ² with 2 mol (meth) acrylate Acrylate, which reacts with 1 mol of the above intermediate product.

(In the formula (9), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and represents an integer of 0 to 2; ;x represents an integer from 0 to 3)

The method of synthesizing the urethane (meth) acrylate corresponding to the repeating unit of the formula (3) is exemplified as follows. [1] The diisocyanate having R ^{1 and} the ester having R ² are reacted in a molar ratio of m:m(r+s), and further, a m+1 molar diol having R ³ is reacted to obtain An intermediate product having a hydroxyl group at both ends. [2] Thereafter, a urethane corresponding to the repeating unit represented by the general formula (10) can be obtained by reacting 2 mol of an isocyanate having a (meth) acrylonitrile group with 1 mol of an intermediate product. (Meth) acrylate.

(In the formula (10), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s The sum is 1~2; x means the integer from 0~3)

The method of synthesizing the urethane (meth) acrylate corresponding to the repeating unit of the formula (4) is exemplified as follows. [1] A diisocyanate having R ¹ is reacted with a diol having R ³ at a molar ratio of m:m+1 to obtain an intermediate product having a hydroxyl group at both terminals. The urethane (meth) acrylate corresponding to the repeating unit represented by the formula (11) can be obtained by any one of the following [2-1], [2-2] or [2-3] ester. [2-1] Thereafter, 2 mol of an isocyanate having a (meth) acrylonitrile group is allowed to react with 1 mol of the above intermediate product; [2-2] an ester of 1 to ² having an R ² group After reacting the above intermediate product with the ear, 2 mol of isocyanate having a (meth) acrylonitrile group is reacted; [2-3] an ester having R ² of k + n molar has (meth) propylene with 2 mol The urethane (meth) propylene acrylate obtained by the thiol isocyanate reaction is reacted with 1 mol of the above intermediate product.

(In the formula (11), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturation different from R ¹ ; a cyclic aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and represents an integer of 0 to 2; ;x represents an integer from 0 to 3)

The structure of the representative monomer which produces block B is shown below.

(In the formula (12), R ⁶ represents a saturated cyclic aliphatic group; R ⁷ represents a hydrogen atom or a methyl group; and y and z represent an integer of 0 to 2)

The thiol (R-SH) used in the present invention, during the reaction with the urethane (meth) acrylate, H becomes a single bond, and in addition to the above thioether structure (RS-) is common to the hydrocarbon R. Specific examples of the hydrocarbon R have been described in the above-described thioether structure, and therefore the description of the hydrocarbon R is not repeated.

Representative thiols which produce a thioether structure are shown below.

(In the formula (13), R ⁸ represents an alkyl chain having a carbon number of 1 or 2 in which a hydrogen atom may be substituted by a methyl group; n represents an integer of 1 to 4)

Further, other structures of a representative thiol which produces a thioether structure are shown below.

(In the formula (14), R ⁹ represents an alkyl chain having 1 or 2 carbon atoms which may be substituted by an alkyl group; R ¹⁰ represents a hydrogen atom or a methyl group; q represents an integer of 1 to 4)

A suitable thiol is shown below: In the above formula (14), R ⁹ is an ethyl chain, and a β-carbon bonded to a methyl group in the ethyl chain; q is 4. The thiol is tetrafunctional and produces a thioether structure which forms a complex three-dimensional structure with the repeating unit.

The energy ray-hardening composition is prepared by adding a photopolymerization initiator which polymerizes the starting monomer to a monomer which produces a repeating unit. In other forms, the preparation of the energy ray-hardening composition The addition of the starter to the monomer which produces the repeating unit (block A) is also carried out by the monomer and/or mercaptan which produces the block B.

As the photopolymerization initiator, the following polymerization initiators may be used singly or in combination, and the like: acetophenone-based, benzophenone-based, thioxanthone-based, benzoin, benzoin methyl ether and the like A polymerization initiator; a cationic polymerization initiator such as an aromatic diazonium salt, an aromatic onium salt, an aromatic onium salt or a metallocene compound.

Various additives such as the above-mentioned ultraviolet absorber, leveling agent, and antistatic agent in "protective film" may be added to the energy ray-curable composition.

a monomer in an energy ray-hardening composition (a total amount of a monomer which produces a repeating unit (block A) and a monomer which produces a block B), a thiol, a photopolymerization initiator, and any various additives The ratio of each of the materials varies depending on the type of the material, and it is difficult to uniformly define the ratio. The total amount of the monomer and the mercaptan is 50% by mass or more and 99% by mass or less, and the photopolymerization initiator is 0.5% by mass or more and 10% by mass. % or less; various additives are 0.01% by mass or more and 50% by mass or less. Further, an organic solvent such as toluene may be added to the energy ray-curable composition.

In order to increase the degree of tensile elastic modulus of the protective film resulting from the block B, the weight ratio of the monomer A of the block A to the monomer B which produces the block B is produced, and the monomer A: single The range of body B=70:30~15:85 is better, 60:40~15:85 is better, and 50:40~15:85 is especially good.

For the mercaptan, in order to increase the degree of tensile strength of the protective film resulting from the thioether structure, the above monomer (monomer A, Or the weight ratio of the monomer A to the monomer B) to the mercaptan having a thioether structure, preferably the monomer: mercaptan = 95:5 to 50:50, and more preferably 90:10 to 70:30. .

In order to apply the prepared energy ray-curable composition on the release layer of the film substrate or the film substrate, in view of continuous productivity, a coating method such as a roll coating method or a gravure coating method is preferably used. The energy ray-curable composition can be applied by the coating method to form a protective film of a thin layer (for example, 50 μm or less, preferably 30 μm or less).

The hardening in the step (A2) can be carried out by irradiating ultraviolet rays from the ultraviolet irradiation device. The ultraviolet light source to be used is not particularly limited, and may be used, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, etc. having a light-emitting distribution at a wavelength of 400 nm or less. . When an epoxy compound is used as an adhesive of an active energy ray-curable component, a high-pressure mercury lamp or metal halide having a large amount of light of 400 nm or less is preferably used in consideration of an absorption wavelength exhibited by a general polymerization initiator. The light comes as an ultraviolet light source.

By curing the energy ray-curable composition and forming a protective film on the film substrate or the release layer of the film substrate, a film laminate in which a protective film is laminated on the film substrate can be obtained. Further, a single protective film can also be obtained by peeling off the protective film from the film laminate.

[Function layer formation step]

As a variation of the method for producing a thin film laminated body, a manufacturing method including the functional layer forming step (B) before the protective film forming steps (A1) and (A2) can be mentioned. The functional layer forming step (B) is on a film substrate or a film On the release layer of the substrate, an energy ray-curable composition belonging to the material of the functional layer is applied and hardened to form a functional layer on the film substrate.

The functional layer is not particularly limited, and examples thereof include the hard coat layer, the antiglare layer, and the antireflection layer. The energy ray-curable composition belonging to the functional layer raw material includes the above-described resin and the like in the description of the hard coat layer, the antiglare layer, and the antireflection layer. Further, an organic solvent such as methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone (MIBK), isopropyl alcohol (IPA) or toluene may be added.

In the case of coating an energy ray-curable composition which is a raw material of a functional layer on a film substrate or a release layer of a film substrate, in view of continuous productivity, a roll coating method, a gravure coating method, or the like is preferably used. Coating method. A method of crosslinking and hardening by ultraviolet irradiation or the like after being arbitrarily heated in accordance with the energy ray-curable composition to be used.

When the functional layer is formed on the film substrate in the functional layer forming step, the energy ray-curable composition containing the urethane (meth) acrylate is applied to the film in the protective film forming step (A1). The functional layer side of the substrate. When the functional layer is a plurality of layers, it is usually coated on the side of the finally formed functional layer.

When a film substrate having irregularities is formed, irregularities are formed on the functional layer formed on the film substrate, and the function is exhibited as an antiglare layer having antiglare properties. The uneven shape is determined according to the required anti-glare property, and a more suitable uneven shape can be defined by the roughness parameter Ra, and Ra: 0.01 μm or more, Sm: 50 μm to 500 μm, and an average tilt angle: 0.1 °. 3.0 ° is preferred.

When a functional layer is formed, a plurality of layers can also be formed. For example, when a plurality of hard coat layers are formed, a first hard coat layer is formed on the film substrate or on the release layer of the film substrate, and a second hard coat layer is formed on the first hard coat layer. Thereafter, in the step (A1), an energy ray-curable composition containing a urethane (meth) acrylate is applied to the second hard coat layer side. An anti-glare layer may be formed instead of the second hard coat layer.

Further, when the antireflection layer is formed, a low refractive index layer is formed on the film substrate or on the release layer of the film substrate, and a high refractive index layer is formed on the low refractive index layer. Further, an energy ray-curable composition containing a urethane (meth) acrylate is coated on the high refractive index layer side in the step (A1). Thereby, a film laminate in which a film substrate, a functional layer, and a protective film are laminated in this order can be obtained.

"Manufacturing method of polarizing plate"

The polarizing plate of the present invention comprises the protective film of the present invention on at least one side of the polarizing film. In the method for producing a polarizing plate of the present invention, it is important that the protective film is bonded to a polarizing film, and a known method can be used for the bonding method, and is not particularly limited.

As the protective film, a protective film can be used alone, but from the viewpoint of ease of handling, it is preferred to use a film laminate, that is, a protective film is used together with the film substrate.

For example, after the protective film forming step, or after the functional layer forming step and the protective film forming step, after obtaining the laminated body having the protective film, the polarizing film is bonded to the protective film side of the thin film laminated body to obtain the present invention. The polarizing plate of the invention.

More specifically, the steps of the method of manufacturing the polarizing plate will be described. Following The steps (C1) to (C4) are carried out after the protective film forming step, or after the functional layer forming step and the protective film forming step.

(C1) coating step: applying an ultraviolet curing type adhesive to the protective film side (or polarizing film) of the film laminate; (C2) bonding step: on the ultraviolet curing type adhesive surface coated by the coating step, The polarizing film (or the protective film side of the film laminate) is superposed and pressurized; (C3) the curing step: the film laminate having the protective film bonded to the polarizing film through the ultraviolet curing adhesive is irradiated by the ultraviolet irradiation device Ultraviolet rays cure the ultraviolet curable adhesive; (C4) Peeling step: peeling off the film substrate (supporting substrate) from the laminated film as needed.

In the coating step (C1), an ultraviolet curable adhesive is applied to the protective film side of the film laminate which is the bonding surface of the polarizing film (or in place of the protective film side of the film laminate, ultraviolet light curing is applied to the polarizing film). Type of adhesive). As the applicator used herein, a known one can be suitably used, and for example, a coater using a gravure roll or the like can be used.

In the bonding step (C2), after the coating step (C1), the polarizing film is superimposed and pressed while being applied to the adhesive-coated surface of the film laminate (in the coating step (C1), When the ultraviolet curable adhesive is applied to the polarizing film, the protective film side of the film laminate is superimposed on the ultraviolet curable adhesive surface and pressed while being pressed. The pressurization in the bonding step can be carried out by a known means, and from the viewpoint of being able to perform pressurization in a continuous conveyance state, it is preferably passed through a pair of nip rolls to pass through a pair of nip rolls. Line when clamped The pressure gauge during pressurization is preferably about 150 to 500 N/cm.

In the hardening step (C3), after the polarizing film is bonded to the film laminate, ultraviolet rays are irradiated from the ultraviolet irradiation device to cure the ultraviolet curing adhesive. The ultraviolet ray is irradiated through the film laminate. The ultraviolet light source to be used is not particularly limited, and for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, or the like having a light-emitting distribution at a wavelength of 400 nm or less can be used. . When an epoxy compound is used as an adhesive for the energy ray-curable component, a high-pressure mercury lamp or a metal halide lamp having a large amount of light of 400 nm or less is preferably used as the absorption wavelength exhibited by a general polymerization initiator. Ultraviolet light source.

The peeling step (C4) is a step of appropriately removing the film substrate laminated on the protective film by this step (when the film substrate is a plurality of layers, peeling off a part of the film substrate and Remove) to obtain a polarizing plate. When the surface of the protective film is to be protected in the post-processing step in the case of further processing the polarizing plate or the like, the film substrate may be peeled off after the completion of the processing.

[Examples]

Hereinafter, the present invention will be described based on examples and comparative examples, but the present invention is not limited to the contents of the examples. The protective film for peeling off the polyester film substrate from the obtained film laminate (when the functional layer is formed on the film substrate, the protective film and the functional layer) is the object of measurement, and the moisture permeability and tensile strength of the protective film are It was measured by the following measurement method.

[film thickness]

Use Digital Linear Gauge D-10HS and number The film thickness of the protective film (or protective film + functional layer) was measured by a digital counter C-7HS (manufactured by Ozaki Co., Ltd.).

[transmotive humidity]

According to the moisture permeability test method (cup method) of JIS Z0208, for the protective film, the amount of water vapor passing through the test piece area per 1 m ² in 24 hours in a gas atmosphere at a temperature of 40 ° C and a humidity of 90% RH was measured. number.

[self-reliance]

For the sample film which has been cut into a size of 15 mm × 160 mm, the long side is stretched, and "Tensiron RTF-24" (manufactured by YAMATO Scientific) is used to make the sample film 100 mm between the jigs. The both ends were held in a jig, and the maximum inclination of the stress-strain curve at a load range of 40 N and a measurement speed of 20 mm/min was measured at a normal temperature (25 ° C) to obtain a tensile elastic modulus and/or a tensile strength.

In the evaluation of the self-supporting property, when the tensile elastic modulus of the sample film is 1500 MPa or more and less than 2500 MPa, it is judged as ○; when the tensile elastic modulus is 2500 MPa or more, it is judged as ◎; when it is ○ or ◎, It is judged to be self-reliant. On the other hand, when the formed film collapsed at the stage of peeling from the PET film, it was judged that it was impossible to measure and was judged as ×.

On the other hand, in the case of the tensile strength, when the tensile strength of the sample film is 15 MPa or more and less than 25 MPa, it is judged as ○; when the tensile strength is 25 MPa or more, it is judged as ◎; when it is ○ or ◎ At the time, it was judged to be self-reliant. On the other hand, when the formed film collapsed at the stage of peeling from the PET film, it was judged that it was impossible to measure and was judged as ×.

[Manufacturing Example 1]

Synthesis of Compound 1:

196.29 g (1 mol) of tricyclodecane dimethanol and 228.29 g (2 mol) of ε-caprolactone were placed in a flask, and the temperature was raised to 120 ° C, and 50 ppm of monobutyltin oxide was added as a catalyst. Thereafter, the reaction was carried out under a nitrogen stream until the remaining ε-caprolactone became 1% or less in gas chromatography to obtain a diol (1).

In a separate flask, 444.58 g (2 mol) of isophorone diisocyanate was charged, and at a reaction temperature of 70 ° C, diol (1) 425.57 g (1 mol) was added, and the residual isocyanate group became 5.7%. At that time, 232.24 g (2 mol) of 2-hydroxyethyl acrylate and 0.35 g of dibutyltin laurate were added, and the reaction was carried out until the residual isocyanate group became 0.1%, and an amine belonging to a monomer which produces a repeating unit (block A) was obtained. The urethane acrylate (Compound 1) (the repeating unit of Compound 1 is m in the formula (1a)).

[Manufacturing Example 2]

Synthesis of Compound 2:

114.14 g (1 mol) of ε-caprolactone and 116.12 g (1 mol) of 2-hydroxyethyl acrylate were reacted at 120 ° C under a nitrogen stream, relative to 100 parts by mass of ε-caprolactone 114.14 g. (1 mol), 5 parts by mass of spherical activated carbon BAC made of Kureha (stock) was added as a catalyst, and in order to suppress radical polymerization of 2-hydroxyethyl acrylate, 4-methoxyphenol was added to the entire polymerization system. 500mg/Kg. Thereafter, the reaction was carried out until ε-caprolactone became 1% or less in gas chromatography, and ε-caprolactone-modified hydroxyethyl acrylate (2) was obtained.

The flask was charged with 444.58 g (2 mol) of isophorone diisocyanate, and 196.29 g (1 mol) of tricyclodecane dimethanol was added at a reaction temperature of 70 ° C, and ε was added when the residual isocyanate group became 5.7%. - Inside Ester-modified hydroxyethyl acrylate (2) 2 mol 460.52 g, and reacted until the residual isocyanate group became 0.1%, and the urethane acrylate (compound 2) belonging to the monomer which produces the repeating unit was obtained (Compound 2) The repeating unit is in the formula (2a), m is 1).

[Manufacturing Example 3]

The reaction was carried out in the same manner as in Production Example 1 except that the amount of the synthesis of the diol (1) was changed to 2 times, and the amount of the isophorone diisocyanate was changed from 2 moles to 3 moles. The monomer compound 1a (the repeating unit of the compound 1a is m in the formula (1a)).

[Manufacturing Example 4]

The compound 1b (compound) was obtained in the same manner as in Production Example 1 except that the amount of the synthesis of the diol (1) was changed to 3 times and the amount of the isophorone diisocyanate was changed from 2 moles to 4 moles. The repeating unit of 1b is m (3) in the formula (1a).

[Example 1: Polyester film substrate / protective film]

The following energy-curing composition (P1) for forming a protective film was applied to the release layer side of non-ketone-based release PET SG-1 (thickness: 38 μm) manufactured by Panac Co., Ltd. using an applicator. The energy ray-curable composition (P1) contained toluene and had a solid content ratio (NV) of 60%.

The coating thickness of the energy ray-curable composition (P1) is adjusted so that the film thickness after drying becomes 20 μm to 30 μm. The coating film was dried in a clean oven set at 100 ° C in a drying oven, and thereafter, under a nitrogen atmosphere, the peak illuminance was 326 mW/cm ² and the cumulative light amount was 192 mJ/cm ² . The film was cured by ultraviolet rays to obtain a film laminate in which a protective film was formed on one side of the PET film. The evaluation results of the film laminate were shown in Table 7.

[Example 2: polyester film substrate / HC layer / protective film]

The following energy layer-curable composition (HC1) for forming an HC layer was applied to the release layer side of non-fluorenone-based release PET SG-1 (thickness: 38 μm) manufactured by Panac Co., Ltd. by a reverse coating method. The formed coating film was dried at 100 ° C for 1 minute, and irradiated with ultraviolet light (irradiation distance 10 cm, irradiation time 30 seconds) using a 1 盏 120 W/cm concentrating high-pressure mercury lamp under a nitrogen atmosphere, hardening coating The film was formed into a hard coat layer (HC layer) having a thickness of 2.5 μm and a refractive index of 1.52.

Then, the energy ray-curable composition (P1) described in Example 1 was applied and dried on the HC layer side under the same conditions as in Example 1, to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 7.

[Example 3: polyester film substrate / AG layer (containing filler) / protective film]

By the bar coating method, the release film was applied so as to have a dry film thickness of 2 μm on one side of a PET film (product name: EMTILET S-50) which is a support for a release film. The solution was applied, and the film was dried at 140 ° C for 1 minute, and then hardened. In this manner, a support having a release layer having a thickness of 2 μm on the PET film was obtained, and the release layer having a thickness of 2 μm had surface irregularities. Next, an energy ray-curable composition (AG1) for forming an AG layer described below was applied onto the release layer.

The coating thickness was adjusted so that the dry film thickness was 6 μm by bar coating. After the coating film of AG1 was dried at 100 ° C for 1 minute, ultraviolet irradiation (light: high pressure mercury lamp, lamp output: 120 W/cm, integrated light amount: 120 mJ/cm) was performed to cure the coating film. Then, the energy ray-curable composition (P1) described in Example 1 was applied and dried on the side of the AG layer under the same conditions as in Example 1 to obtain protection on the side of the AG layer. A thin film laminate of a film. The evaluation results of the film laminate were shown in Table 7.

[Example 4: Polyester film substrate / HC layer (without filler AG) / protective film]

By a bar coating method, a single layer of a PET film (product name: EMBLET S-50) of a support film which is a release film is coated on the release layer so that the dry film thickness becomes 2 μm. The coating liquid was dried by drying the coating film at 140 ° C for 1 minute. In this manner, a support having a release layer having a thickness of 2 μm on the PET film was obtained, and the release layer having a thickness of 2 μm had surface irregularities. Then, in the same manner as the application of AG1 of Example 3, the following energy layer-curable composition (HC2) for forming an HC layer was applied onto the release layer, followed by curing.

Then, the energy ray-curable composition (P1) described in Example 1 was applied and dried on the HC layer side under the same conditions as in Example 1, to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 7.

[Example 5: polyester film substrate / low refractive index layer / high refractive index layer and AG layer / protective film]

By a bar coating method, a coating film for a release layer is applied to one side of a PET film (product name: EMBLET S-50) of a support of a release film so that the dry film thickness becomes 2 μm. The coating liquid was dried by drying the coating film at 140 ° C for 1 minute. In this manner, a support having a release layer having a thickness of 2 μm on the PET film was obtained, and the release layer having a thickness of 2 μm had surface irregularities.

The following low refractive index coating material (LR1) was applied onto the release layer by a reverse coating method, and the coating film was dried at 100 ° C for 1 minute to form a low refractive index having a thickness of 0.1 μm and a refractive index of 1.38. Floor. Thereafter, it was allowed to stand at 60 ° C for 120 hours for the hardening of the low refractive index layer.

Then, the energy ray-curable composition (AG1) for forming an AG layer described in Example 3 was applied onto the low refractive index layer by a bar coating method so that the dry film thickness was 6 μm, at 100 ° C. After drying for 1 minute, ultraviolet irradiation (light: high pressure mercury lamp, lamp output: 120 W/cm, integrated light amount: 120 mJ/cm) was performed to cure the coating film to form an AG layer.

Then, the energy ray-curable composition described in Example 1 was applied and dried on the AG layer side under the same conditions as in Example 1. The material (P1) was obtained, and a film laminate having a protective film formed on the side of the AG layer was obtained. The evaluation results of the film laminate were shown in Table 7.

[Example 6: polyester film substrate / low refractive index layer / high refractive index layer and HC layer / protective film]

The low refractive index coating material (LR1) described in Example 5 was applied to the peeling layer side of non-ketone-based peeled PET SG-1 (thickness: 38 μm) manufactured by Panac Co., Ltd. using an applicator, and the coated film 1 was dried at 100 ° C. After a minute, it was hardened to form a low refractive index layer having a thickness of 0.1 μm and a refractive index of 1.38. Thereafter, it was allowed to stand at 60 ° C for 120 hours for the hardening of the low refractive index layer.

Next, an energy ray-curable composition (HC3) for forming an HC layer described below is applied onto the low refractive index layer by a reverse coating method. After drying at 100 ° C for 1 minute, ultraviolet irradiation (irradiation distance: 10 cm, irradiation time: 30 seconds) was carried out in a nitrogen atmosphere at 120 W/cm concentrating high-pressure mercury lamp, and the coating film was cured to have a thickness of 2.5 μm. An HC layer having a refractive index of 1.64.

Sexual composition 60%)

*2 The average particle size of ITO powder is 0.05 μm, which is 5 mol% relative to the Sn content of In.

Then, the energy ray-curable composition (P1) described in Example 1 was applied and dried on the HC layer side under the same conditions as in Example 1, to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 7.

[Examples 7 to 9: polyester film substrate/protective film]

In the seventh embodiment, the compound 1 is changed to the compound 2; in the eighth embodiment, the compound 1 is changed to the compound 1a; and in the embodiment 9, the compound 1 is changed to the compound 1b, and the modification is carried out in addition to the modification. In the same manner as in Example 1, a film laminate in which a protective film was formed on one surface of a PET film was obtained. The evaluation results of the film laminate were shown in Table 7.

[Comparative Example 1]

In the same manner as in Example 1, except that the compound 1 was changed to the compound 3 (manufactured by Shin-Nakamura Chemical Co., Ltd.) of the following formula (12a), a cured film was formed on one side of the PET film to obtain a film laminate. . The evaluation results of the film laminate were shown in Table 7.

Table 7

As shown in Table 7, when the compound 1 of Examples 1 to 6 and the compound 2 of Example 7 were used, a protective film having a very low moisture permeability was obtained. Further, in Examples 2 to 6, the moisture permeability became lower due to the functional layer. In terms of the tensile modulus of elasticity, a high value can also be obtained, and a very useful protective film can be obtained. The protective films using the compounds 1a and 1b as raw materials in Examples 8 and 9 were inferior to those in Example 1 (Compound 1), but achieved low moisture permeability. Moreover, the evaluation of the tensile elastic modulus is ○, and the protective film of the present invention can obtain sufficient self-standing property.

On the other hand, since the cured film formed in Comparative Example 1 was very hard and brittle, it peeled off from the PET film, and measurement of film thickness, moisture permeability, and tensile strength could not be performed, and there was no self-standing property at all. When the compound 3 is synthesized, since a monomer having only one saturated cyclic aliphatic group is used, the repeating unit of the compound 3 contains only one saturated cyclic aliphatic group. Therefore, it is considered that the cohesive force between the repeating units becomes too high, and a cured film having high brittleness is formed.

[Example 10: polyester film substrate / protective film]

The energy ray-curable composition (P2) for forming a protective film described below was applied to the release layer side of non-ketone-based release PET SG-1 (thickness: 38 μm) manufactured by Panac Co., Ltd. using an applicator. The energy ray-curable composition (P2) contained toluene and had a solid content ratio (NV) of 60%.

The coating thickness of the energy ray-curable composition (P2) is adjusted so that the film thickness after drying becomes 20 μm to 30 μm. The coating film was dried in a dust-free oven set at 100 ° C in a drying oven, and then ultraviolet-cured under a nitrogen atmosphere at a peak illuminance of 326 mW/cm ² and an integrated light amount of 192 mJ/cm ² . A film laminate in which a protective film is formed on one side of a PET film is obtained. The evaluation results of the film laminate were shown in Table 9.

[Example 11: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 10 except that the monomer (95 parts by mass of the compound 1) used in Example 10 was 66.5 parts by mass of the compound 1 and 28.5 parts by mass of the compound 3. A film laminate having a protective film formed on the surface. The compound 3 is a monomer which produces the block B, and is represented by the following formula (12a). The evaluation results of the above film laminate were shown in Table 9.

[Example 12: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 10 except that the monomer (95 parts by mass of the compound 1) used in Example 10 was 47.5 parts by mass of the compound 1 and 47.5 parts by mass of the compound 3. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 9.

[Example 13: polyester film substrate / HC layer / protective film]

In the same manner as in Example 2, an HC layer was formed on a PET film (PET SG-1). Then, the energy ray-curable composition used in Example 12 was applied and dried on the HC layer side under the same conditions as in Example 12 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 9.

[Example 14: polyester film substrate / AG layer (containing filler) / protective film]

In the same manner as in Example 3, the coating film of AG1 was cured on a PET film (product name: EMBLET S-50 manufactured by UNITIKA). Then, the energy ray-curable composition used in Example 12 was applied and dried on the side of the AG layer under the same conditions as in Example 12 to obtain a thin film layered body in which a protective film was formed on the side of the AG layer. The evaluation results of the film laminate were shown in Table 9.

[Example 15: Polyester film substrate / HC layer (without filler AG) / protective film]

In the same manner as in Example 4, PET film (UNITIKA product) Name: EMBLET S-50) Forms the HC layer. Then, the energy ray-curable composition used in Example 12 was applied and dried on the HC layer side under the same conditions as in Example 12 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 9.

[Example 16: Polyester film substrate / low refractive index layer / high refractive index layer and AG layer / protective film]

In the same manner as in Example 5, a low refractive index layer was formed on the PET film, and an AG layer was further formed on the low refractive index layer. Then, the energy ray-curable composition used in Example 12 was applied and dried on the side of the AG layer under the same conditions as in Example 12 to obtain a thin film layered body in which a protective film was formed on the side of the AG layer. The evaluation results of the film laminate were shown in Table 9.

[Example 17: polyester film substrate / low refractive index layer / high refractive index layer and HC layer / protective film]

In the same manner as in Example 6, a low refractive index layer was formed on the PET film, and an HC layer was formed on the low refractive index layer. Then, the energy ray-curable composition used in Example 12 was applied and dried on the HC layer side under the same conditions as in Example 12 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 9.

[Example 18: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 10 except that the monomer (95 parts by mass of the compound 1) used in Example 10 was 28.5 parts by mass of the compound 1 and 66.5 parts by mass of the compound 3. A film laminate having a protective film formed on the surface. The evaluation of the film laminate The price results are shown in Table 9.

[Example 19: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 10 except that the monomer (95 parts by mass of the compound 1) used in Example 10 was 19 parts by mass of the compound 1 and 76 parts by mass of the compound 3. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 9.

[Comparative Example 2]

A film having a protective film formed on one surface of a PET film was obtained in the same manner as in Example 10 except that the monomer (95 parts by mass of the compound 1) used in Example 10 was 95 parts by mass of the compound 3. Laminate (no compound 1 is used). The evaluation results of the film laminate were shown in Table 9.

[Example 20]

In the same manner as in Example 10 except that the compound 1 was changed to the compound 2, a cured film was formed on one side of the PET film to obtain a film laminate. The evaluation results of the film laminate were shown in Table 9.

[Example 21]

In the same manner as in Example 20, except that the monomer (95 parts by mass of the compound 2) used in Example 20 was 57 parts by mass of the compound 2 and 38 parts by mass of the compound 3, on one side of the PET film. A cured film is formed to obtain a thin film laminate. The evaluation results of the film laminate were shown in Table 9.

[Example 22]

In addition to the monomer used in Example 10 (95 parts by mass of the compound) In the same manner as in Example 10 except that the compound 1) was 95 parts by mass of the compound 1a, a cured film was formed on one side of the PET film to obtain a film laminate. The evaluation results of the film laminate were shown in Table 9.

[Example 23]

In the same manner as in Example 10, except that the monomer (95 parts by mass of the compound 1a) used in Example 22 was 38 parts by mass of the compound 1a and 57 parts by mass of the compound 3, on one side of the PET film. A cured film is formed to obtain a thin film laminate. The evaluation results of the film laminate were shown in Table 9.

As shown in Table 9, in the case of Example 10, only Compound 1 was used as a monomer and Compound 3 was not used, and the obtained protective film had a moisture permeability of 77 g/(m ² .24 h) in a film thickness of 24 μm. . Next, in the case of Example 11, it is understood that when Compound 3 is used as the monomer B, the moisture permeability of the obtained protective film is 60 g/(m ² .24 h), and a protective film having a low moisture permeability can be obtained.

Next, in Example 12, when the ratio of the compound 3 was increased, it was confirmed that the moisture permeability was further lowered. In Examples 13 to 17, it was found that when the functional layer was provided on the protective film, the low moisture permeability was maintained. In Example 18 and Example 19, when the ratio of the compound 3 was further increased, it was confirmed that the moisture permeability was further lowered. Further, it was confirmed that the protective films obtained in Examples 11 to 19 had a high tensile modulus of elasticity and were sufficiently self-standing.

On the other hand, in Comparative Example 2, when Compound 1 was used as the monomer without using Compound 1, the cured film obtained was very hard and brittle, and collapsed when peeled off from the PET film, so that the film thickness could not be obtained. The measurement of moisture permeability and tensile strength is completely free of self-reliance. When the compound 3 is synthesized, a monomer having only one saturated cyclic aliphatic group is used, and the compound 3 contains only one saturated cyclic aliphatic group. Therefore, it is considered that the cohesive force between the monomer units becomes too high, and a cured film having high brittleness is formed.

In the case of Example 20, Compound 2 was used as a monomer; in the case of Example 21, Compound 3 was used in addition to Compound 2, and from the comparison of the two examples, the moisture permeability of Example 21 was confirmed. Reduce the effect. From the comparison of Example 22 using Compound 3 as a monomer with Example 23, the effect of reducing the moisture permeability of Example 23 was confirmed.

[Example 24: polyester film substrate / protective film]

Non-ketone-based peeling PET made by Panac using an applicator The peeling layer side of SG-1 (thickness: 38 μm) was applied to the energy ray-curable composition (P2) for forming a protective film used in Example 10. The energy ray-curable composition (P2) contained toluene and had a solid content ratio (NV) of 60%.

The coating thickness of the energy ray-curable composition (P2) is adjusted so that the film thickness after drying is 20 μm to 30 μm. The coating film was dried in a dust-free oven set at 100 ° C in a drying oven, and then ultraviolet rays were irradiated under a nitrogen atmosphere at a peak illuminance of 326 mW/cm ² and an integrated light amount of 192 mJ/cm ² . It is hardened to obtain a film laminate in which a protective film is formed on one side of the PET film. The evaluation results of the film laminate were shown in Table 10.

[Example 25: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24 except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 90.25 parts by mass of the compound 1 and 4.75 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The compound 4 (manufactured by Showa Denko KK) is a thiol, and its structure is represented by the following formula (14a). The evaluation results of the above film laminate were shown in Table 10.

[Example 26: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 85.5 parts by mass of the compound 1 and 9.5 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. Evaluation of the film laminate The results are shown in Table 10.

[Example 27: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 76 parts by mass of the compound 1 and 19 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 10.

[Example 28: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 66.5 parts by mass of the compound 1 and 28.5 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 10.

[Example 29: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 57 parts by mass of the compound 1 and 38 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 10.

[Example 30: polyester film substrate / HC layer / protective film]

In the same manner as in Example 2, an HC layer was formed on a PET film (PET SG-1). Then, the energy ray-curable composition used in Example 26 was applied and dried on the HC layer side under the same conditions as in Example 26 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 10.

[Example 31: polyester film substrate / AG layer (containing filler) / protective film]

In the same manner as in Example 3, the coating film of AG1 was cured in a PET film (product name: EMBLET S-50 manufactured by UNITIKA). Then, the energy ray-curable composition used in Example 26 was applied and dried on the AG layer side under the same conditions as in Example 26 to obtain a thin film layered body in which a protective film was formed on the side of the AG layer. The evaluation results of the film laminate were shown in Table 10.

[Example 32: Polyester film substrate / HC layer (without filler AG) / protective film]

In the same manner as in Example 4, an HC layer was formed on a PET film (product name: EMBLET S-50 manufactured by UNITIKA). Then, the energy ray-curable composition used in Example 26 was applied and dried on the HC layer side under the same conditions as in Example 26 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 10.

[Example 33: polyester film substrate / low refractive index layer / high refractive index layer and AG layer / protective film]

In the same manner as in Example 5, a low refractive index layer was formed on the PET film, and an AG layer was further formed on the low refractive index layer. Then, the energy ray-curable composition used in Example 26 was applied and dried on the side of the AG layer under the same conditions as in Example 26 to obtain a thin film layered body in which a protective film was formed on the side of the AG layer. The evaluation results of the film laminate were shown in Table 10.

[Example 34: Polyester film substrate / low refractive index layer / high fold Emissivity layer and HC layer/protective film]

In the same manner as in Example 6, a low refractive index layer was formed on the PET film, and an HC layer was formed on the low refractive index layer. Then, the energy ray-curable composition used in Example 26 was applied and dried on the HC layer side under the same conditions as in Example 26 to obtain a thin film layered body in which a protective film was formed on the HC layer side. The evaluation results of the film laminate were shown in Table 10.

[Example 35]

The same procedure as in Example 24 was carried out except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 95 parts by mass, and a protective film was formed on one side of the PET film. Thin film laminate (No compound 1 is used). The evaluation results of the film laminate were shown in Table 10.

[Example 36: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 85.5 parts by mass of the compound 2 and 9.5 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 10.

[Example 37]

A film having a protective film formed on one side of the PET film was obtained in the same manner as in Example 25, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 95 parts by mass of the compound 1a. Laminate (no compound 1 is used). The evaluation results of the film laminate were shown in Table 10.

[Example 38: polyester film substrate / protective film]

In the same manner as in Example 24 except that the monomer (95 parts by mass of the compound 1) used in the Example 24 was changed to 76 parts by mass of the compound 1a and 19 parts by mass of the compound 4, one side of the PET film was obtained. A thin film laminate having a protective film formed thereon. The evaluation results of the film laminate were shown in Table 10.

[Example 39]

A film in which a protective film was formed on one surface of a PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 95 parts by mass of the compound 1b. Laminate (no compound 1 is used). The evaluation results of the film laminate were shown in Table 10.

[Example 40: polyester film substrate / protective film]

A single film of PET film was obtained in the same manner as in Example 24, except that the monomer (95 parts by mass of the compound 1) used in Example 24 was 90.25 parts by mass of the compound 1b and 4.75 parts by mass of the compound 4. A film laminate having a protective film formed on the surface. The evaluation results of the film laminate were shown in Table 10.

Table 10

As shown in Table 10, in the case of Example 24, only Compound 1 was used as a monomer and Compound 4 was not used, and the obtained protective film had a film thickness of 24 μm and a moisture permeability of 77 g/(m ² .24 h). The tensile strength was 20 MPa. Next, in Example 25, the compound 4 which is a mercaptan was used in combination with the compound 1, and the protective film obtained was a film thickness of 25 μm and a moisture permeability of 86 g/(m ² .24 h) and a tensile strength of 30 MPa. Comparing the two results, it can be understood that in the case of Example 25, although the moisture permeability was slightly increased, the tensile strength was changed to 1.5 times, and the tensile strength was greatly increased.

Next, in the case of Example 26, when the ratio of the compound 4 was increased, it was confirmed that although the moisture permeability was slightly increased as compared with Example 25, the tensile strength was further increased. For Examples 27 and 28, when the ratio of Compound 4 was increased to 20% and 30%, respectively, the tensile strength was increased more than that of Example 26. In the case of Example 29, when the proportion of Compound 4 was further increased to 40%, the result was that the tensile strength was 3 times that of Example 24. Very high value, the moisture permeability is also very high.

In Examples 30 to 34, it was found that a protective film was provided on the protective film, and a protective film having excellent tensile strength was obtained in the same manner as in Example 26.

In the examples after Example 35 and subsequent examples, the compound 1 was changed to another monomer having a plurality of saturated cyclic aliphatic groups. In the case of Example 35, the compound 1 was changed to the compound 2, and the compound 4 which is a thiol was not used in combination, and the protective film obtained was a film thickness of 23 μm and a moisture permeability of 93 g/(m ² .24 h). On the other hand, in Example 36, when 10% of the thiol compound 4 was used in combination with the compound 2, it was confirmed that the tensile strength was about twice as high as that of Example 35, and the tensile strength of the protective film was improved. tendency.

Similarly, when Example 37 and Example 38 were carried out on Compound 1a and Example 39 and Example 40 were carried out on Compound 1b, it was confirmed that the compound 1a and 1b were protected by the use of the thiol compound 4. The tensile strength of the film tends to increase.

From the evaluation results described in Table 10, it is clearly understood that in the production of a protective film, a urethane (meth) acrylate having a plurality of saturated cyclic aliphatic groups is polymerized by using a thiol compound. The formed protective film has low moisture permeability and high self-standing property.

[Industrial availability]

Since the protective film of the present invention is low in moisture permeability and self-standing in a thin layer state, it is useful as a constituent member of a polarizing plate in applications requiring low moisture permeability, and can be used in various fields.

Claims (16)

A protective film comprising a copolymer comprising a repeating unit belonging to block A and a block B, the repeating unit belonging to block A having a bifunctional aminocarboxylic acid derived from a structure of an ester (meth) acrylate comprising a structure derived from a bifunctional (meth) acrylate having one saturated cyclic aliphatic group, the repeating unit having a plurality of kinds of saturation A cyclic aliphatic group. The protective film according to claim 1, which comprises a polymer chain composed of a plurality of the repeating units, and at least a structure having a thioether bond is bonded to the polymer chain or at the end of the polymer chain. Protection film according to Item 1 request, wherein the repeating unit comprises: a saturated cyclic aliphatic group R ¹ of the following structure A, and a saturated cyclic aliphatic group R of the following structure C ^3, -CO-NH -R ¹ -NH-CO-‧‧‧ (Structure A)-OR ³ -O-‧‧‧ (Structure C). The protective film of claim 3, wherein the repeating unit further comprises: the following structure B comprising a saturated aliphatic chain R ² , -OR ² -CO-‧‧ (structure B). The protective film of claim 4, wherein the repeating unit is a structure represented by the following formula (1), In the formula (1), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; An aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s are The sum is 1~2; x means an integer from 0~3. The protective film of claim 3, wherein the repeating unit is a structure represented by the following formula (2), In the formula (2), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure having 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and n represents an integer of 0 to 2; x represents an integer from 0 to 3. The protective film of claim 4, wherein the repeating unit is a structure represented by the following formula (3), In the formula (3), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; An aliphatic group; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; r and s each represent an integer of 0 to 2, and r and s are The sum is 1~2; x means an integer from 0~3. The protective film of claim 3, wherein the repeating unit is a structure represented by the following formula (4), In the formula (4), R ¹ represents a saturated cyclic aliphatic group; R ² represents a saturated aliphatic chain having a linear or branched structure of 5 to 10 carbon atoms; and R ³ represents a saturated ring different from R ¹ ; R ⁴ represents a hydrogen atom or a methyl group; R ⁵ represents a hydrogen atom, a methyl group or an ethyl group; m represents an integer of 1 to 4; k represents an integer of 0 to 2; and n represents an integer of 0 to 2; x represents an integer from 0 to 3. The protective film of claim 3, wherein the R ¹ is a 3-methylene-3,5,5-trimethylcyclohexane ring; and R ³ is a dimethylene tricyclodecane ring. The protective film of claim 1, wherein the block B is a structure represented by the following formula (5), In the formula (5), R ⁶ represents a saturated cyclic aliphatic group; R ⁷ represents a hydrogen atom or a methyl group; and y and z represent an integer of 0 to 2. The protective film of claim 10, wherein the R ⁶ is a tricyclodecane ring. The protective film of claim 2, wherein the structure having a thioether bond is a structure represented by the following formula (6), In the formula (6), R ⁸ represents an alkyl chain having a carbon number of 1 or 2 in which a hydrogen atom may be substituted by a methyl group; X each independently represents -S- or -SH; and n represents an integer of 1 to 4. The protective film of claim 2, wherein the structure having a thioether bond is a structure represented by the following formula (7), In the formula (7), R ⁹ represents an alkyl chain having a carbon number of 1 or 2 in which a hydrogen atom may be substituted by an alkyl group; X each independently represents -S- or -SH; and R ¹⁰ represents a hydrogen atom or a methyl group; Indicates an integer from 1 to 3. The protective film of claim 1 has a moisture permeability of 150 g/(m ² ‧24 hours) or less, a tensile modulus of elasticity of 1,500 MPa or more, or a tensile strength of 25 MPa or more. A thin film laminated body comprising any one of the following (1) to (4) on at least one surface of the protective film of claim 1, (1) a film substrate supporting the protective film, ( 2) a hard coat layer having scratch resistance, (3) an antiglare layer for scattering light, and (4) a high refractive index layer provided on the protective film and a low refractive index of the high refractive index layer An antireflection layer composed of layers. A polarizing plate comprising a protective film according to claim 1 on at least one side of a polarizing film.