WO2013118566A1 - Procédé pour la production de film optique - Google Patents

Procédé pour la production de film optique Download PDF

Info

Publication number: WO2013118566A1
Authority: WO; WIPO (PCT)
Prior art keywords: cellulose ester; range; optical film; resin; solvent
Prior art date: 2012-02-08
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Ceased

Application number

PCT/JP2013/050971

Other languages

English (en)

Japanese (ja)

Inventor

睦美笠原

山田　るみ子

直輝高橋

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Konica Minolta Advanced Layers Inc

Original Assignee

Konica Minolta Advanced Layers Inc

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

2012-02-08

Filing date

2013-01-18

Publication date

2013-08-15

2013-01-18 Application filed by Konica Minolta Advanced Layers Inc filed Critical Konica Minolta Advanced Layers Inc

2013-08-15 Publication of WO2013118566A1 publication Critical patent/WO2013118566A1/fr

2014-08-08 Anticipated expiration legal-status Critical

Status Ceased legal-status Critical Current

Images

Classifications

- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
- C08L33/04—Homopolymers or copolymers of esters
- C08L33/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
- C08L33/10—Homopolymers or copolymers of methacrylic acid esters
- C08L33/12—Homopolymers or copolymers of methyl methacrylate
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
- C08L1/08—Cellulose derivatives
- C08L1/10—Esters of organic acids, i.e. acylates
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
- G02B1/105—
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
- G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
- G02B1/14—Protective coatings, e.g. hard coatings

Definitions

the present invention relates to a method for producing an optical film. More specifically, the present invention relates to a method for producing an optical film in which surface roughness does not occur even when a film having a thinner film thickness than that of the conventional film is formed by a melt casting method and gel-like foreign matters are reduced.
PMMA Polymethyl methacrylate
acrylic resins a representative of conventional acrylic resins
the PMMA film has poor heat resistance, and there has been a problem that the shape changes when used under high temperatures or for long-term use.
the present invention has been made in view of the above-described problems and situations, and a solution to the problem is that a conventional optical film is formed by melt casting using a resin composition containing an acrylic resin and a cellulose ester resin. It is an object of the present invention to provide a method for producing an optical film in which surface roughness does not occur and gel-like foreign matters are reduced when a film is formed thinner than this film thickness.
the present inventor in the process of examining the cause of the above problems, surface roughness generated during melt casting film formation, residual unreacted monomer that is an impurity in the acrylic resin, residual polymerization start It has been found that the reactivity of the agent, the residual chain transfer agent, etc. is increased by heating, and is produced by the formation of a high molecular weight substance that is presumed to be an aggregation of acrylic resin or cellulose ester resin. It has also been found that residual unreacted monomers, residual polymerization initiators and residual chain transfer agents, which are impurities in the acrylic resin, become gel-like foreign substances by reacting with part of the cellulose ester resin.
the present inventors have found that surface roughness and generation of gel-like foreign matters can be suppressed by reducing the generation of a high molecular weight substance that is presumed to be an aggregation of an acrylic resin or a cellulose ester resin.
a method for producing an optical film for melt casting using a resin composition containing at least an acrylic resin and a cellulose ester resin in a mass ratio within a range of 95: 5 to 30:70 comprising: A method for producing an optical film, characterized in that the high molecular weight product formation rate H defined by the following formula is within the range of 0 to 10%.
H (a / b) ⁇ 100 (%)
H is a molecular weight (Mw) on the horizontal axis and a detection sensitivity value on the vertical axis in gel permeation chromatography (GPC) measurement of the resin composition containing the acrylic resin and the cellulose ester resin.
Mw molecular weight
GPC gel permeation chromatography
the positive differential area (a) is an area on the higher molecular weight side than the molecular weight value indicating the GPC detection sensitivity peak value before heating of the resin composition.
the weight average molecular weight Mw of the acrylic resin is in the range of 2.0 ⁇ 10 4 to 5.0 ⁇ 10 5 , and the content of residual unreacted monomer in the acrylic resin is in the range of 100 to 1000 ppm. 2.
the above-mentioned means of the present invention is used to form a film with a thickness smaller than that of a conventional optical film by melt casting using a resin composition containing an acrylic resin and a cellulose ester resin, surface roughness occurs. And a method for producing an optical film with reduced gelled foreign matters can be provided. Moreover, the optical film manufactured by this optical film manufacturing method can be provided.
the phenomenon of surface roughness is that an unintended high molecular weight body is generated in the resin composition when the resin composition is heated and melted, and the high molecular weight body is the resin composition. Since the compatibility with the product is inferior, it is presumed that it appears on the surface of the web in the film forming stage and the surface state becomes irregular uneven shape.
Acrylic resins are usually obtained by polymerizing monomers such as methyl methacrylate in the presence of a polymerization initiator or chain transfer agent, so that residual components such as unreacted monomers, polymerization initiators, chain transfer agents, etc. May be included. It is presumed that these residual components are activated at the time of heat-melting and react with an acrylic resin or a cellulose ester resin to produce the unintended high molecular weight body. At the same time, it is presumed that the residual component reacts with a part of the cellulose ester resin to form a gel-like foreign material.
the resin composition containing the acrylic resin and the cellulose ester resin is heated at a specific temperature and time condition to suppress the formed high molecular weight polymer within a certain amount, so that the residual unreacted
the content of monomers, residual polymerization initiators and residual chain transfer agents can be reduced, and unintentional high molecular weight products can be suppressed.
a method for producing an optical film in which surface roughness does not occur and gelled foreign matters are reduced can be provided.
GPC peak area before heating of resin composition containing acrylic resin and cellulose ester resin (b) Change in peak area of GPC before and after heating resin composition containing acrylic resin and cellulose ester at 260 ° C. for 1 hour Positive differential area according to the present invention (a) Diagram showing an example of acrylic resin synthesis method Schematic diagram showing an example of film production equipment
the method for producing an optical film of the present invention is an optical film for melt casting using a resin composition containing at least an acrylic resin and a cellulose ester resin in a mass ratio within a range of 95: 5 to 30:70.
a production method characterized in that the high molecular weight product formation rate H calculated by the above method of the resin composition is in the range of 0 to 10%, and this structure is an effect of the present invention. Even when the cast film is formed thinner than the conventional film thickness, the occurrence of surface roughness is prevented.
the weight average molecular weight Mw of the acrylic resin is in the range of 2.0 ⁇ 10 4 to 5.0 ⁇ 10 5 and
the content of residual unreacted monomer is preferably in the range of 100 to 1000 ppm.
the residual initiator content of the acrylic resin is in the range of 10 to 500 ppm, and the residual chain transfer agent content is in the range of 10 to 500 ppm, which further enhances the effect of preventing surface roughness. Therefore, it is preferable.
the cellulose ester resin is a purified cellulose ester resin produced by the method for producing the specific cellulose ester resin.
the cellulose ester resin reacts with the residual unreacted monomer, the residual polymerization initiator and the residual chain transfer agent to produce the high molecular weight product. Which component of the cellulose ester resin is denatured into the high molecular weight material still remains. Do not go out of speculation. However, it has been found that the use of a purified cellulose ester resin produced by the method for producing a cellulose ester resin can reduce the generation of high molecular weight bodies and, at the same time, reduce the occurrence of gelled foreign substances.
the content of the alkali metal or the Group 2 element in the cellulose ester resin is in the range of 1 to 150 ppm, respectively, because the effect of reducing the occurrence of gelled foreign matters can be further enhanced.
the thickness of the optical film is preferably in the range of 10 to 35 ⁇ m from the viewpoint of thinning the liquid crystal display.
the optical film produced by the method for producing an optical film of the present invention is an optical film which is a thin film, excellent in surface shape and high in heat resistance, and suitable for various display devices other than a polarizing plate protective film and a liquid crystal display device. It is.
⁇ is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
the surface roughness referred to in the present invention refers to a phenomenon in which irregular irregularities are generated on the film surface with a size that can be visually confirmed. For example, it refers to a state in which the surface of the optical film is rough like a pine skin or a dried rice paper.
the phenomenon of surface roughness is that an unintended high molecular weight product is generated in the resin composition when the resin composition is heated and melted, and the high molecular weight material is poor in compatibility with the resin composition. It is presumed that it appears on the surface of the web in the film forming stage and the surface state becomes irregular irregular shapes.
the gel-like foreign material is a minute foreign material that can be confirmed with a microscope or the like.
the shape is various, for example, it is specified as a gel by the following test method.
the number of gel-like foreign matters in the optical film is, for example, cut out 1 m 2 minutes from the winding of the optical film obtained by melt casting film formation, hitting the light of the fluorescent lamp to the film, and visually checking the uneven reflection of the surface Then, the content of the confirmed part is examined with an optical microscope, separated from external foreign substances such as dust, and the longest diameter (the longest diameter connecting the end portion of the particle projection image) is less than 100 ⁇ m. Are counted as the number of gel-like foreign matters.
the gelled foreign matter is preferably less than 100 pieces / m 2 , more preferably 50 pieces / m 2 or less, and particularly preferably 10 pieces / m 2 or less.
FIG. 1 shows a GPC measurement before heating using a resin composition containing an acrylic resin and a cellulose ester resin.
the horizontal axis is the molecular weight and the vertical axis is a waveform plotted with the detection sensitivity value. b).
FIG. 2 is an example of a change in the waveform of GPC before and after a resin composition containing an acrylic resin and a cellulose ester resin was heated at a temperature of 260 ° C. for 1 hour.
FIG. 3 shows the detection sensitivity obtained by subtracting the GPC detection sensitivity value before heating the resin composition from the GPC detection sensitivity value after heating the resin composition of acrylic resin and cellulose ester resin at 260 ° C. for 1 hour.
the value difference is plotted against the horizontal axis molecular weight (Mw).
the positive difference area (a) of the detection sensitivity value difference as used in the field of this invention is an area which exists in the high molecular weight side from the molecular weight value which shows the GPC peak before the heating of this resin composition.
the polymer production rate H according to the present invention is a value obtained by dividing the positive difference area (a) by the area (b) of the GPC before heating, as shown by the following formula.
Formula H (a / b) ⁇ 100 (%)
a resin composition containing an acrylic resin and a cellulose ester resin, which are samples is applied to about 5 to 10 mg of a sample using a thermal analysis apparatus (EXSTAR6000 TG / DTA) manufactured by SII. Heat for 1 hour while maintaining the temperature at 260 ° C. in a nitrogen stream.
the heating condition of 260 ° C. for 1 hour is set by simulating the temperature and elapsed time that the resin composition receives from the production apparatus during the melt casting film formation.
the molecular weight is measured by the following GPC using the obtained sample before and after heating.
the area of the area (b) and the positive difference area (a) from the waveform measured by GPC it can be calculated using area analysis software.
the area can be obtained using a multi-station GPC-8020 model II manufactured by Tosoh Corporation.
the resin composition containing the acrylic resin and the cellulose ester resin is generating a high molecular weight product by heating during melt casting film formation.
this value can be kept within the range of 0 to 10% in a practical system, the surface roughness of the optical film formed thinner than before is rough. The above range was set after confirming that there was no.
the high molecular weight production rate H according to the present invention is required to obtain the effect of the present invention within the range of 0 to 10%, and preferably within the range of 0 to 6%. And the generation of gel-like foreign matters are preferred from the viewpoint of being able to significantly suppress the generation.
the acrylic resin according to the present invention may be an acrylic resin having an aromatic ring in the side chain or an acrylic resin having a cyclohexyl group in the side chain, and the weight average molecular weight Mw of the acrylic resin is 2.0 ⁇ 10 4 to It is preferably within the range of 5.0 ⁇ 10 5 . Within this range, excellent heat resistance and compatibility with the cellulose ester resin are excellent.
the acrylic resin according to the present invention includes an ethylenically unsaturated monomer Xa having no aromatic ring and a hydroxy group in the molecule, and an ethylenically unsaturated monomer Xb and Xa having no aromatic ring in the molecule and having a hydroxy group.
a polymer Y obtained by copolymerizing a saturated monomer Yb and a copolymerizable ethylenically unsaturated monomer excluding Ya and Yb is preferable.
the polymer X includes an ethylenically unsaturated monomer Xa that does not have an aromatic ring and a hydroxy group or an amide group in the molecule, and an ethylenically unsaturated monomer Xb that does not have an aromatic ring in the molecule and has a hydroxy group or an amide group. And a copolymerizable ethylenically unsaturated monomer excluding Xa and Xb.
Xa is an acrylic or methacrylic monomer that does not have an aromatic ring and a hydroxy group or an amide group in the molecule
Xb is an acrylic or methacrylic monomer that does not have an aromatic ring in the molecule and has a hydroxy group or an amide group.
the polymer X used in the present invention is represented by the following general formula (X).
Xa represents an ethylenically unsaturated monomer that does not have an aromatic ring and a hydroxy group or an amide group in the molecule
Xb does not have an aromatic ring in the molecule and has a hydroxy group or an amide group
Xc represents a copolymerizable ethylenically unsaturated monomer excluding Xa and Xb.
polymer X is preferably a polymer represented by the following general formula (X-1).
R 1 and R 3 each represent a hydrogen atom or a methyl group.
R 2 represents an alkyl group having 1 to 12 carbon atoms or a cycloalkyl group.
R 4 represents —CH 2 —, —C 2 H 4 —, or C 3 H 6 —.
Xc represents a monomer unit polymerizable to [CH 2 —C (—R 1 ) (— CO 2 R 2 )] or [CH 2 —C (—R 3 ) (— CO 2 R 4 —OH) —].
the monomers as monomer units constituting the polymer X used in the present invention are listed below, but are not limited thereto.
the hydroxy group means not only a hydroxy group but also a group having an ethylene oxide chain.
the ethylenically unsaturated monomer Xa having no aromatic ring and hydroxy group or amide group in the molecule is, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate ( n-, i-), nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid ( ⁇ -caprolactone), etc.
the ethylenically unsaturated monomer Xb having no aromatic ring in the molecule and having a hydroxy group or an amide group is preferably acrylic acid or methacrylic acid ester as a monomer unit having a hydroxy group, for example, acrylic acid (2-hydroxy Ethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), or these acrylic acids replaced with methacrylic acid Acrylic acid (2-hydroxyethyl) and methacrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), and acrylic acid (3-hydroxypropyl) are preferable.
Xb As monomer units having an amide group in Xb, N-vinylpyrrolidone, N-acryloylmorpholine, N-methacryloylmorpholine, N-vinylpiperidone, N-vinylcaprolactam, acrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N , N-dimethylaminopropylacrylamide, N, N-diethylacrylamide, N-hydroxyethylacrylamide, N-vinylacetamide and the like.
Xc is not particularly limited as long as it is a monomer other than Xa and Xb and is a copolymerizable ethylenically unsaturated monomer, but preferably has no aromatic ring.
the molar composition ratio m: n of Xa and Xb is preferably in the range of 99: 1 to 65:35, and more preferably in the range of 95: 5 to 75:25.
P of Xc is 0-10. Xc may be a plurality of monomer units.
haze tends to occur during film formation, and it is preferable to optimize these and determine the molar composition ratio of Xa and Xb.
the polymer Y used in the present invention does not have an aromatic ring in the molecule with styrene or its derivative Ya, and has an ethylenically unsaturated monomer Yb having a hydroxy group and a copolymerizable ethylenically unsaturated group excluding Ya and Yb.
a polymer Y obtained by copolymerizing with a monomer is preferred.
the polymer Y used in the present invention is represented by the following general formula (Y).
Monomers as monomer units constituting the polymer Y of the present invention are listed below, but are not limited thereto.
the hydroxy group means not only a hydroxy group but also a group having an ethylene oxide chain.
Styrene or its derivative Ya is styrene or a compound in which other groups are bonded to styrene as a styrene derivative.
alkylstyrene such as methylstyrene, 2,4-dimethylstyrene, ethylstyrene, hydroxystyrene
alkylstyrene such as methylstyrene, 2,4-dimethylstyrene, ethylstyrene, hydroxystyrene
examples include methoxystyrene, acetoxystyrene, butoxystyrene, ethoxyethoxystyrene, and substituted styrene in which a hydroxy group, an alkoxy group, or the like is introduced into the benzene nucleus of styrene.
the ethylenically unsaturated monomer Yb having no aromatic ring in the molecule and having a hydroxy group or an amide group is preferably acrylic acid or methacrylic acid ester as a monomer unit having a hydroxy group, for example, acrylic acid (2-hydroxy Ethyl), acrylic acid (2-hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), or these acrylic acids replaced with methacrylic acid Acrylic acid (2-hydroxyethyl) and methacrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), and acrylic acid (3-hydroxypropyl) are preferable.
Yb As monomer units having an amide group in Yb, N-vinylpyrrolidone, N-acryloylmorpholine, N-methacryloylmorpholine, N-vinylpiperidone, N-vinylcaprolactam, acrylamide, N, N-dimethylacrylamide, N-isopropylacrylamide, N , N-dimethylaminopropylacrylamide, N, N-diethylacrylamide, N-hydroxyethylacrylamide, N-vinylacetamide and the like.
Yc is not particularly limited as long as it is a monomer other than Ya and Yb and is a copolymerizable ethylenically unsaturated monomer, but preferably has no aromatic ring.
the molar composition ratio m: n of Ya and Yb is preferably in the range of 5:95 to 60:40, more preferably in the range of 10:90 to 40:60.
P of Yc is 0-10. Yc may be a plurality of monomer units.
haze tends to occur during film formation, and it is preferable to optimize these and determine the molar composition ratio of Ya and Yb.
the hydroxy group value of the polymers X and Y is preferably 30 to 150 [mgKOH / g].
the hydroxy group value is measured according to JIS K 0070 (1992). This hydroxy group value is defined as the number of mg of potassium hydroxide required to neutralize acetic acid bound to a hydroxy group when 1 g of a sample is acetylated.
sample Xg (about 1 g) is precisely weighed in a flask, and 20 ml of an acetylating reagent (a solution obtained by adding pyridine to 20 ml of acetic anhydride to 400 ml) is accurately added thereto. Attach an air cooling tube to the mouth of the flask and heat in a glycerin bath at 95-100 ° C. After 1 hour and 30 minutes, the mixture is cooled, 1 ml of purified water is added from an air condenser, and acetic anhydride is decomposed into acetic acid.
an acetylating reagent a solution obtained by adding pyridine to 20 ml of acetic anhydride to 400 ml
titration is performed with a 0.5 mol / L potassium hydroxide ethanol solution using a potentiometric titrator, and the inflection point of the obtained titration curve is set as the end point.
hydroxy group value is calculated by the following formula.
Hydroxy group value ⁇ (BC) ⁇ f ⁇ 28.05 / X ⁇ + D
B is the amount (ml) of 0.5 mol / L potassium hydroxide ethanol solution used for the blank test
C is the amount (ml) of 0.5 mol / L potassium hydroxide ethanol solution used for titration
f is a factor of a 0.5 mol / L potassium hydroxide ethanol solution
D is an acid value
28.05 is 1/2 of 1 mol amount 56.11 of potassium hydroxide.
polymer X and polymer Y are both excellent in compatibility with the cellulose ester resin, excellent in productivity without evaporation and volatilization, good retention as a protective film for polarizing plates, low moisture permeability, dimensions Excellent stability.
the acrylic resin according to the present invention is preferably subjected to a polymerization reaction by introducing a composition containing the monomer, a polymerization initiator, and a chain transfer agent into a reaction vessel.
radical polymerization initiators examples include organic peroxides such as t-butyl hydroperoxide, cumene hydroperoxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate; potassium persulfate, ammonium persulfate Persulfates such as: 2,2′-azobis (2-methylpropionitrile) (AIBN), azo compounds such as azobis-2,4-dimethylvaleronitrile; redox in which organic peroxide and reducing agent are combined System initiators; redox initiators in which a persulfate and a reducing agent are combined are included. Only one type of radical polymerization initiator may be used, or a mixture of two or more types may be used. The amount of radical polymerization initiator charged can be about 0.01 to 1% by mass relative to the total amount of monomer components.
chain transfer agents examples include alkyl mercaptans having 3 to 18 carbon atoms.
alkyl mercaptans include n-octyl mercaptan, dodecyl mercaptan and the like.
the charge amount of the chain transfer agent can be about 0.05 to 1% by mass with respect to the total amount of the monomer components.
the copolymerization may be suspension polymerization, emulsion polymerization, solution polymerization or bulk polymerization.
the copolymerization since no solvent is used during polymerization, separation of the resulting polymer and solvent is unnecessary, and bulk polymerization is preferred because there is little mixing of an emulsifier, a dispersant, and the like into the polymer.
the polymerization temperature in suspension polymerization or emulsion polymerization can be in the range of 30 to 100 ° C .; the polymerization temperature in bulk polymerization is preferably in the range of 80 to 300 ° C.
the polymerization reaction in bulk polymerization can be performed in a polymerization reactor, a heater, and a devolatilizing extruder as described later.
the polymerization time can be in the range of 1 to 10 hours, for example.
FIG. 4 is a diagram showing an example of an acrylic resin synthesis method. The figure shows an example of bulk polymerization of methyl methacrylate (MMA) and acryloylmorpholine (ACMO).
MMA methyl methacrylate
ACMO acryloylmorpholine
MMA methyl methacrylate
ACMO acryloylmorpholine
catalyst a polymerization initiator
MMA methyl methacrylate
ACMO acryloylmorpholine
the obtained catalyst solution and monomer mixture are mixed in a polymerization reactor to polymerize methyl methacrylate (MMA) and acryloylmorpholine (ACMO). Thereby, a liquid polymer composition is obtained.
the polymerization temperature in the polymerization reactor is preferably in the range of 80 to 200 ° C, more preferably in the range of 80 to 180 ° C.
the polymerization reaction of methyl methacrylate (MMA) and acryloylmorpholine (ACMO) in the polymerization reactor is carried out in order to obtain a fluid polymer composition (liquid polymerization composition).
the average polymerization rate of the resulting polymerization composition is 10% by mass or more.
An average polymerization rate shows the ratio (mass ratio) of the polymer contained in a liquid polymer composition.
the obtained liquid polymer composition is supplied to a devolatilizing extruder while being heated by a heater.
the heater is a heat retaining means for feeding the liquid polymer composition to the devolatilizing extruder without lowering its temperature.
the heating temperature in the heater can be preferably in the range of 150 to 250 ° C.
volatile components including unreacted monomers and the like
the melting temperature can preferably be in the range of 200-300 ° C. After the melt-kneaded melt is extruded, it is cooled with water and cut to obtain acrylic resin pellets.
Acrylic resin In particular, an acrylic resin obtained by bulk polymerization tends to contain residual components such as unreacted monomers (methyl methacrylate and copolymerization monomers), unreacted radical polymerization initiators, and unreacted chain transfer agents.
unreacted monomers methyl methacrylate and copolymerization monomers
unreacted radical polymerization initiators unreacted chain transfer agents.
an acrylic resin and a cellulose ester resin containing these residual components are melt-kneaded at a high temperature, the high molecular weight product formation rate H increases and a high molecular weight product is easily generated.
the cause of the formation of high molecular weight during melt kneading is not necessarily clear, but is presumed as follows. That is, it is considered that the high molecular weight product is produced by a chemical or physical action of a polymer obtained by polymerizing an unreacted monomer and a cellulose ester resin. Moreover, in the filtration filter for removing the foreign material in molten resin, since the residence time of the heated molten resin tends to become long, a high molecular weight body is easy to produce
Acrylic resin with a large molecular weight is not only difficult to melt and extrude because of the high viscosity of the melt, but the film obtained by melt-kneading the resin composition of acrylic resin and cellulose ester resin produces a high molecular weight body. It's easy to do.
the obtained acrylic resin preferably satisfies the following requirements a) and b), and more preferably satisfies the requirements c) and d).
the weight average molecular weight Mw is preferably in the range of 2.0 ⁇ 10 4 to 5.0 ⁇ 10 5 .
the total content of residual unreacted monomers is preferably in the range of 100 to 1000 ppm.
the content of the remaining polymerization initiator is preferably in the range of 10 to 500 ppm.
the content of the residual chain transfer agent is preferably in the range of 10 to 500 ppm.
the weight average molecular weight Mw of the acrylic resin is adjusted by the amount of radical polymerization initiator and chain transfer agent charged, the polymerization temperature and polymerization time in the polymerization reactor, the heating temperature in the heater, the melting temperature in the devolatilizing extruder, etc. it can.
the charging amount of a polymerization initiator or a chain transfer agent is increased, the polymerization temperature in the polymerization reactor or the heating temperature in the heater is increased, The polymerization time in the polymerization reactor may be shortened.
the weight average molecular weight Mw of the acrylic resin can be measured by the GPC.
the content of unreacted monomer remaining in the acrylic resin is preferably 1000 ppm or less, and more preferably 500 ppm or less.
the content of the remaining unreacted monomer is more than 1000 ppm, a high molecular weight product is easily generated in a film obtained by melt-kneading a resin composition of an acrylic resin and a cellulose ester resin.
the content of the remaining unreacted monomer is preferably 100 ppm or more. If the content of the remaining unreacted monomer is less than 100 ppm, the flexibility of a film obtained by melt-kneading a resin composition of an acrylic resin and a cellulose ester resin is likely to be lowered (brittle).
the content of the remaining unreacted monomer is determined by the polymerization temperature and polymerization time in the polymerization reactor, the heating temperature in the heater, the melting temperature in the devolatilizing extruder, the unreacted monomer from the vent of the devolatilizing extruder. It can be adjusted by the displacement of volatile components. In order to reduce the content of the remaining unreacted monomer, for example, the polymerization time in the polymerization reactor may be increased, or the exhaust amount of volatile components from the vent of the devolatilizing extruder may be increased.
the content of the unreacted radical polymerization initiator remaining in the acrylic resin is preferably 500 ppm or less, and more preferably 100 ppm or less.
the content of the residual radical polymerization initiator is more than 500 ppm, a high molecular weight product is easily generated in a film obtained by melt-kneading a resin composition of an acrylic resin and a cellulose ester resin.
the content of the remaining radical polymerization initiator is preferably 10 ppm or more.
the content of the residual radical polymerization initiator is less than 10 ppm, the flexibility of a film obtained by melt-kneading a resin composition of an acrylic resin and a cellulose ester resin is likely to be lowered.
the content of the unreacted chain transfer agent remaining in the acrylic resin is preferably 500 ppm or less, and more preferably 100 ppm or less.
the content of the remaining chain transfer agent is more than 500 ppm, the film obtained by melt-kneading the resin composition of the acrylic resin and the cellulose ester resin is likely to be colored.
the content of the remaining chain transfer agent is preferably 10 ppm or more. If the content of the unreacted chain transfer agent is less than 10 ppm, the flexibility of a film obtained by melt-kneading a resin composition of an acrylic resin and a cellulose ester resin is likely to be lowered.
the content of the radical polymerization initiator or chain transfer agent remaining in the acrylic resin is the amount of the radical polymerization initiator or chain transfer agent charged, the polymerization temperature and polymerization time in the polymerization reactor, the heating temperature in the heater, and devolatilization. It can be adjusted by the melting temperature in the extruder. For example, in order to reduce the content of the residual radical polymerization initiator or chain transfer agent, it is possible to reduce the amount charged, increase the polymerization temperature in the polymerization reactor or the heating temperature in the heater, The polymerization time in the reactor may be lengthened.
the content of the residual component contained in the acrylic resin can be measured by the following method.
the contents (mass%) of the monomer, the polymerization initiator, and the chain transfer agent contained in the sample solution are measured by GC / MS.
the GC / MS measurement apparatus and measurement conditions can be as follows.
the amount of radical polymerization initiator or chain transfer agent charged, the polymerization temperature and polymerization time in the polymerization reactor, the heating temperature in the heater, Two or more conditions such as melting temperature and volatile matter discharge amount may be adjusted simultaneously. For example, when only reducing the content of the remaining unreacted monomer, the exhaust amount of volatile matter in the devolatilizing extruder may be increased. However, when the exhaust amount of volatile components in the devolatilizing extruder is increased, the molecular weight of the acrylic resin is also reduced. Therefore, it is only necessary to lower the polymerization temperature or lengthen the polymerization time so that the molecular weight of the acrylic resin does not decrease.
the radical polymerization initiator and chain transfer agent can be consumed (remaining radical polymerization initiator and chain transfer agent are reduced) without excessively increasing the molecular weight. is there. That is, by increasing the polymerization temperature in the polymerization reactor and the heating temperature in the heater, the molecular weight of the acrylic resin (a) is kept below a certain level, and the residual components of the acrylic resins (b) to (d) The content can also be kept below a certain level.
the acrylic resin may be one type or a mixture of two or more types.
the cellulose ester resin used for the optical film of the present invention (hereinafter also simply referred to as cellulose ester) preferably has a total acyl group substitution degree of the cellulose ester in the range of 2.0 to 2.95, and The cellulose ester has a total carbon number of acyl group in the range of 4.0 to 10.
the acyl group total carbon number is the sum of the products of the substitution degree and the carbon number of each acyl group substituted in the glucose unit of the cellulose ester.
the carbon number of the acyl group means the carbon number including the carbonyl group, 2 for the acetyl group, 3 for the propionyl group, and 4 for the butyryl group.
the total number of acyl groups in the present invention is calculated based on the cellulose ester having an acetyl group substitution degree of 1, propionyl group substitution degree of 0.5, and a butyryl group substitution degree of 0.5. It is determined by the formula “degree ⁇ acetyl group carbon number + propionyl group substitution degree ⁇ propionyl group carbon number + butyryl group substitution degree ⁇ butyryl group carbon number”.
the number of carbon atoms of the aliphatic acyl group substituted with the cellulose ester is preferably 2 or more and 6 or less, and more preferably 2 or more and 4 or less, from the viewpoint of productivity and cost of cellulose synthesis.
the portion not substituted with an acyl group usually exists as a hydroxy group.
the glucose unit constituting cellulose with ⁇ -1,4-glycosidic bonds has free hydroxy groups at the 2nd, 3rd and 6th positions.
the cellulose ester according to the present invention is a polymer obtained by esterifying some or all of these hydroxy groups with an acyl group.
the acyl group substitution degree represents the total of the proportions of cellulose esterified at the 2nd, 3rd and 6th positions of the repeating unit. Specifically, the substitution degree is 1 when the hydroxy groups at the 2-position, 3-position and 6-position of cellulose are each 100% esterified. Therefore, when all of the 2nd, 3rd and 6th positions of the cellulose are 100% esterified, the degree of substitution is 3 at the maximum.
acyl group examples include an acetyl group, a propionyl group, a butyryl group, a pentanate group, and a hexanate group.
cellulose ester examples include cellulose acetate, cellulose propionate, cellulose butyrate, and cellulose pentanate.
mixed fatty acid esters such as cellulose acetate, cellulose acetate propionate, cellulose propionate, cellulose acetate butyrate, and cellulose acetate pentanate may be used as long as the above-mentioned side chain carbon number is satisfied.
cellulose acetate, cellulose acetate propionate, and cellulose propionate are particularly preferable cellulose esters for optical film applications.
a preferred cellulose ester other than cellulose triacetate has an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree of acetyl group is X, and the substitution degree of propionyl group or butyryl group is Y, It is a cellulose ester which satisfies (i) and (ii) simultaneously.
Formula (i) 2.0 ⁇ X + Y ⁇ 2.9
Formula (ii) 0.5 ⁇ Y ⁇ 2.7
cellulose acetate propionate is particularly preferably used.
the portion not substituted with an acyl group is usually present as a hydroxy group.
the method for measuring the degree of acyl group substitution can be measured according to ASTM-D817-96.
the cellulose ester according to the present invention preferably has a weight average molecular weight Mw in the range of 50,000 to 500,000, more preferably in the range of 100,000 to 300,000, and still more preferably in the range of 150,000 to 250,000.
the measurement conditions are as follows.
the raw material cellulose of the cellulose ester used in the present invention may be wood pulp or cotton linter, and the wood pulp may be softwood or hardwood.
the cellulose ester made from these can be mixed suitably or can be used independently.
the ratio of cellulose ester derived from cellulose linter: cellulose ester derived from wood pulp (coniferous): cellulose ester derived from wood pulp (hardwood) is 100: 0: 0, 90: 10: 0, 85: 15: 0, 50:50: 0, 20: 80: 0, 10: 90: 0, 0: 100: 0, 0: 0: 100, 80:10:10, 85: 0: 15, 40:30:30.
cellulose having a high degree of polymerization is preferable.
linter pulp is preferable, and it is preferable to use cellulose composed of at least linter pulp.
the ⁇ -cellulose content which is an index of the crystallinity of cellulose, is in the range of 90% or more (eg, about 92 to 100%, preferably 95 to 100%, more preferably about 99.5 to 100%). .
the cellulose ester resin which concerns on this invention is the refined cellulose ester resin manufactured by the manufacturing method of the following cellulose ester resins, suppresses the production
the type of cellulose ester and the type of solvent so as to satisfy the following production methods, in particular, the formula (1) and the formula (2), the crystallized product obtained by the difference in the substituent and degree of substitution of the cellulose ester is coarse. It is a preferable method for obtaining a purified uniform cellulose ester resin by suppressing the growth to a crystallized product.
the cellulose ester resin according to the present invention is a method for producing a cellulose ester having a step of mixing a cellulose ester solution and a poor solvent and precipitating the cellulose ester, wherein the water content relative to the solvent contained in the cellulose ester solution is The total number of acyl groups per glucose unit of the cellulose ester that is within the range of 10 to 60% by mass and the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent and the precipitated cellulose ester It is preferable to manufacture by the manufacturing method of the cellulose-ester resin in which carbon number (t) satisfy
Formula (1) a s + 0.8t Formula (2) 31 ⁇ a ⁇ 40
s is the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent
t is the total number of acyl group carbon atoms per glucose unit of the cellulose ester. 0.8t above) Is a term relating to the contribution of the acyl group to the SP value.
the cellulose ester solution should just be a solution containing a cellulose ester.
a cellulose solution immediately before the cellulose ester precipitation step for example, cellulose activation step, acylation reaction step, aging step.
the cellulose ester solution which passed through the neutralization reaction process is pointed out.
the method for producing the cellulose ester resin is characterized in that the water content of the entire solvent contained in the cellulose ester solution is in the range of 10 to 60% by mass, and both good dispersibility and solubility of the cellulose ester are achieved. From the viewpoint of the above, it is preferably in the range of 15 to 50% by mass.
the amount is 50% by mass or less, the cellulose ester is easily dissolved and the productivity is improved. If the amount is 60% by mass or less, the effect of reducing gel-like foreign matters is great and the production is also easy.
the solvent used to obtain the cellulose ester solution is a mixed solvent containing water as described above, and any solvent can be used as long as the cellulose ester dissolves.
the SP value is preferably in the range of 18.5 to 37.0 (MPa) 1/2 .
a solvent having an SP value within the above range can easily dissolve the cellulose ester.
the solubility parameter (SP value) of the solvent referred to in the present invention is a value represented by the square root of the molecular aggregation energy, and is described in Polymer Hand Book (Second Edition) Chapter IV Solubility Parameter Values.
the unit is (MPa) 1/2 and indicates a value at 25 ° C.
R.D. F. It can be calculated by the method described in Fedors, Polymer Engineering Science, 14, p147 (1967).
the total sum of the mass fraction of each solvent used with respect to the total solvent and the SP value of each solvent is taken as the SP value of the mixed solvent.
a single solvent that does not dissolve the cellulose ester may be used for the cellulose ester solution, and the formulas (1) and (2) may be satisfied in a state where the solvent of the cellulose ester solution and the poor solvent are mixed. It ’s fine.
Specific organic solvents used for the solvent and poor solvent of the cellulose ester solution include, for example, methanol (29.7), ethanol (28.0), water (47.9), butyric acid (19.9), and propion. Acid (20.3), ethyl acetate (18.6), tetrahydrofuran (18.6), benzene (18.8), trichloroethyl (18.8), methyl ethyl ketone (19.0), chloroform (19.0) , Methylene chloride (19.8), acetone (20.2), acetic acid (20.7), pyridine (21.9), n-butanol (23.3), isopropyl alcohol (23.5), dimethylformamide ( 24.8).
the numerical value in the parenthesis represents the SP value (MPa) 1/2 .
the solvent of the cellulose ester solution preferably contains a solvent responsible for dissolving the cellulose ester.
a solvent responsible for dissolving the cellulose ester Specifically, an organic solvent having an SP value in the range of 18.5 to 25.0 is preferably used. It is done.
the solvent responsible for dissolution preferably has an SP value in the range of 18.5 to 23.5, and more preferably has an SP value in the range of 18.5 to 22.0.
Preferred solvents include ethyl acetate, tetrahydrofuran, methyl ethyl ketone, methylene chloride, acetone and acetic acid.
these solvents may be combined with any solvent.
a mass ratio of acetic acid: water is in the range of 90:10 to 65:35
a mixed solvent of acetic acid, methanol and water a mass ratio of acetic acid / methanol.
a mixed solvent of acetone, methanol and water mass ratio of acetone / methanol is in the range of 100/0 to 8/92). You may contain.
the order of addition of the solvent is not limited, and a solvent adjusted so that the cellulose ester is dissolved may be added to the cellulose ester. You may add a cellulose ester to the solvent which adjusted the value. Moreover, when producing the said cellulose-ester solution using several types of solvent, you may adjust so that it may become in the range of SP value which a cellulose ester melt
the amount of solvent to be used is not particularly limited, but the solid content concentration of the cellulose ester in the cellulose ester solution before mixing with the poor solvent is preferably in the range of 5 to 30% by mass. If it is 30% by mass or less, it is difficult for foreign substances to be taken into the solid when the cellulose ester is precipitated, and if it is 5% by mass or more, the cellulose ester can be precipitated even if the amount of the poor solvent used is small. Productivity is improved.
the temperature of the step of dissolving the cellulose ester is not particularly limited as long as it is a temperature at which the cellulose ester dissolves, and there is no problem even when heated to reflux with a boiling point or higher, but it is preferably in the range of ⁇ 20 to 80 ° C.
the “poor solvent” refers to a solvent in which the cellulose ester does not dissolve by 10% by mass or more at 20 ° C., and refers to a solvent added to precipitate the cellulose ester from the cellulose ester solution. Moreover, in the manufacturing process of a cellulose ester, the solvent added in order to precipitate a cellulose ester after the neutralization reaction performed after the aging process for performing partial hydrolysis is called a poor solvent, and when the aging process is not performed, The solvent added to precipitate the cellulose ester after the neutralization reaction performed after the acylation reaction step is referred to as a poor solvent.
the poor solvent may be adjusted so that the numerical value of the total SP value of the solvent combined with the solvent used for the cellulose ester solution is within the range of the formulas (1) and (2). It is preferable that the SP value is adjusted to be higher than that of the solvent used for the cellulose ester solution. If the numerical value of the SP value of the whole solvent is within the range of the above formulas (1) and (2), the crystallized product is dissolved and can be separated from the precipitation of cellulose ester. In addition, if the SP value of the poor solvent is 45.0 or less, it is preferable that the SP value of the poor solvent is adjusted to 45.0 or less because a part of the gel-like foreign matter can be remarkably reduced during the addition. .
a mixed solvent of water and an organic solvent is preferable.
a mixed solvent of water and organic solvent for example, a mixed solvent of water and alcohols (methanol, ethanol, isopropyl alcohol, butanol, etc.), a mixed solvent of water and acetic acid, a mixed solvent of acetone and water, water and acetic acid and Examples include a mixed solvent of alcohols (methanol, ethanol, isopropyl alcohol, butanol, etc.), a mixed solvent of water, acetone, and alcohols (methanol, ethanol, isopropyl alcohol, butanol, etc.).
the alcohol is preferably methanol or ethanol, more preferably methanol.
the poor solvent may be a solvent prepared in advance so that the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent is within the range of the formulas (1) and (2), While mixing the cellulose ester solution and the poor solvent, stepwise while changing the composition ratio and the solvent species so that the SP value of the whole solvent finally falls within the range of the formulas (1) and (2). May be added.
the SP value of the poor solvent added stepwise is preferably 45.0 or less.
the amount of the poor solvent used is preferably in the range of 0.5 to 10.0 times, more preferably in the range of 1.0 to 5.0 times the mass of the cellulose ester solution.
the composition of the cellulose ester solution and the entire poor solvent is adjusted so that the cellulose ester is precipitated within this range, and the maximum SP value of the poor solvent to be mixed is adjusted to 45.0 or less.
a remarkable reduction effect can be obtained for the gel-like foreign matter.
the manufacturing method of the said cellulose ester has the process of mixing a cellulose-ester solution and a poor solvent, and precipitating a cellulose ester. Further, the content of water in the range of 10 to 60% by mass with respect to the whole solvent contained in the cellulose ester solution, and the numerical value of the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent: s And the total number of acyl groups in the cellulose ester: t is within the range satisfying the formulas (1) and (2).
the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent means “the mass fraction of each solvent in the whole solvent after mixing the cellulose ester solution and the poor solvent”. And the sum of the product of the SP value.
the SP value after mixing the cellulose ester solution and the poor solvent is preferably larger than the SP value of the cellulose ester solution.
the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent: s, and the total number of acyl groups in the cellulose ester: t is the following formula (3): And it is more preferable that it is in the range satisfying the formula (4).
0.8 t below is a term relating to the contribution of the acyl group to the SP value.
Formula (3) a s + 0.8t Formula (4) 33 ⁇ a ⁇ 39 Furthermore, it is particularly preferable that the value is within a range satisfying the following formulas (5) and (6).
Formula (5) a s + 0.8t Formula (6) 35 ⁇ a ⁇ 39 If the value of a exceeds the upper limit of the above formulas (1) and (2), the crystallization product is likely to be precipitated, and the crystallization product is taken into the cellulose ester. Fine dispersion of the precipitate may occur, and the filter may pass through the filter during filtration and the yield may decrease.
the target cellulose ester When the value of a falls below the lower limit of the above formulas (1) and (2), the target cellulose ester does not become a crystal, and it itself gels, requiring a large amount of man-hours for filtration, making production difficult.
Alcohol is contained in at least one of the cellulose ester solution or the poor solvent. By precipitating the cellulose ester in a state containing the alcohols, aggregation of the cellulose ester is suppressed, and a precipitate can be obtained uniformly in a better shape. Moreover, since the said alcohol is contained, melt
the alcohol is not particularly limited as long as it is an alcohol having a hydroxy group, but is preferably an aliphatic alcohol.
aliphatic alcohols include methanol, ethanol, propanol, isopropanol, n-butanol, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and the like.
Methanol, ethanol, ethylene glycol, and propylene glycol are preferable, methanol and ethanol are more preferable, and methanol is most preferable.
the amount of the alcohol used is not particularly limited, but is preferably within a range in which the cellulose ester solid does not precipitate when mixed with the cellulose ester solution.
the range in which the effects of alcohols are obtained is preferably within a range of 0.1 to 50 times the mass of the cellulose ester, and more preferably from the mass of the cellulose ester from the viewpoint of shape control of the crystallized product. 10 times or less, and most preferably 5 times or less.
the alcohols may be contained in one or both of the cellulose ester solution and the poor solvent.
a method of adding alcohols to the cellulose ester solution a method of mixing the cellulose ester solution and alcohols, a method of preparing a cellulose ester solution by mixing a mixed solvent containing alcohols and a cellulose ester, cellulose Examples thereof include a method of preparing the cellulose ester solution by adding an ester and an alcohol and then adding another solvent.
the alcohol added in the reaction stopping process or the aging process is excessive, and the residual amount of alcohol is in the range of 0.1 to 50 times the mass of the cellulose ester. You may adjust as follows.
the method for producing the cellulose ester includes a step of mixing the cellulose ester solution and a poor solvent to precipitate the cellulose ester (also referred to as a precipitation step).
the cellulose ester solution and the poor solvent may be mixed by adding the cellulose ester solution to the poor solvent or adding the poor solvent to the cellulose ester solution.
a method of adding a solvent to the cellulose ester solution is preferred.
the solvent used in the precipitation step, the type of solvent used up to the precipitation step, and the preferred mode of the SP value are as described above.
the temperature at which the cellulose ester solution and the poor solvent are mixed is not limited, but is preferably not more than the boiling point of the solvent, more preferably in the range of ⁇ 10 to 60 ° C., more preferably in the range of 0 to 50 ° C. Is within.
an acidic solvent such as acetic acid
hydrolysis of the cellulose ester proceeds and the crystallized product increases remarkably by heating. Therefore, when an acidic solvent such as acetic acid is contained in the cellulose ester solution, the temperature when mixing with the poor solvent is preferably within a range of ⁇ 10 to 40 ° C., more preferably ⁇ 10 to 30 ° C. Within range.
the temperature lowering may be performed by water cooling or the like, or may be performed continuously or stepwise.
the rate of temperature drop may be, for example, in the range of 1 to 20 ° C. per hour, preferably in the range of 3 to 18 ° C., more preferably in the range of 5 to 15 ° C. Good.
the mixing of the cellulose ester solution and the poor solvent is preferably performed with stirring.
the stirring speed depends on the scale (manufacturing scale), but is, for example, in the range of 10 to 10,000 rpm, preferably in the range of 20 to 5000 rpm, more preferably in the range of 30 to 3000 rpm. In particular, it may be in the range of 50 to 2000 rpm.
the stirring speed is in the range of 10 to 2000 rpm (eg 20 to 1500 rpm), preferably in the range of 30 to 1000 rpm (eg 40 to 800 rpm), more preferably 50 to 500 rpm (eg 60 to 300 rpm). It may be within the range, particularly within the range of 70 to 200 rpm. It is desirable that the stirring speed be large enough for granulation. When the stirring speed is too low, localization of the poor solvent to be added and uneven temperature distribution may occur, and the effect of reducing the crystallized product may be reduced.
the method for producing the cellulose ester resin may be performed in the cellulose ester synthesis step.
the cellulose ester synthesis step preferably includes an activation step, an esterification step, an esterification reaction stop step, a filtration step, an aging step, and a neutralization step in this order.
the precipitation step may be provided as a part of a post-treatment step provided after the synthesis step, or may be provided after the post-treatment step is completed.
activation process In the activation step, cellulose is treated with an activator to activate the cellulose.
Raw material cellulose is supplied in a slurry wet state.
acylation solvent organic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid are used. Or an aliphatic carboxylic acid (linear or branched C1-6 alkanoic acid) such as valeric acid. These activators can be used alone or in combination of two or more.
an aqueous medium containing water is used as the activator.
This aqueous medium may be an aqueous medium containing an organic carboxylic acid.
it is economical. It is preferable to use many organic carboxylic acids.
the activation step is not limited to a single activation step, and may be composed of a plurality of activation steps, and can be performed using activators having different concentrations of the acylation catalyst.
the acylating catalyst may be composed of a first activating step for activating cellulose with an activating agent and a second activating step for activating cellulose with an activating agent containing an acylating catalyst. You may comprise in the 1st process of processing cellulose with the activator with a low density
the amount of the activator used is, for example, in the range of 25 to 150 parts by weight, preferably in the range of 30 to 125 parts by weight, more preferably 50 to 100 parts by weight (for example, 70 parts by weight) with respect to 100 parts by weight of cellulose. May be in the range of about 100 parts by mass).
the cellulose may be treated with an activator, the activator may be sprayed on the cellulose, or the cellulose may be immersed in the activator.
raw material cellulose is often added to the activator to form a slurry.
the activation treatment temperature can be selected from the range of 0 to 100 ° C. In order to perform the activation treatment without applying industrial load, it is usually within the range of 10 to 40 ° C., preferably about 15 to 35 ° C. It is.
the activation treatment time can be selected in the range of 0.1 to 72 hours, and is usually in the range of 0.1 to 3 hours, preferably in the range of 0.2 to 2 hours.
the activation process proceeds at the fine pulverization stage, so that the standing time is short, and it can be immediately put into the esterification reaction vessel.
the cellulose activated by the activation treatment is esterified with a carboxylic acid (containing at least one or more) having an acyl group having at least 2 carbon atoms and a carboxylic anhydride (containing at least one or more) in the presence of an acid catalyst.
an acid catalyst Lewis acid or strong acid can be used, but sulfuric acid is generally used.
an acid anhydride for example, an acid anhydride of a carboxylic acid having 2 or more carbon atoms (carboxylic acid anhydride)
a C 2 -C 6 alkane such as acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, etc.
Acid anhydrides can be used.
a carboxylic acid having an acyl group having at least 2 carbon atoms (for example, at least a C 2 -C 6 carboxylic acid anhydride) is used. You may use these individually or in combination of 2 or more types. As long as it has an acyl group and is easily acylated, it is not limited to carboxylic acids, and organic acid halides can also be used.
the amount of the acid catalyst (particularly sulfuric acid) used in the esterification step is, for example, in the range of 3 to 20 parts by mass, preferably in the range of 5 to 18 parts by mass, more preferably 7 to 15 parts per 100 parts by mass of cellulose. It can be selected from the range of about part by mass, and is usually in the range of 7 to 15 parts by mass.
an esterification solvent corresponding to at least an acyl group having 2 or more carbon atoms for example, a carboxylic acid (an acid anhydride) may be used.
a carboxylic acid an acid anhydride
an acid anhydride corresponding to a C 2 to C 6 carboxylic acid A plurality of acid anhydrides selected from those having different carbon numbers may be used.
propionic anhydride and / or butyric anhydride and acetic anhydride may be used in combination.
Preferred esterification solvents are a combination of acetic anhydride and propionic anhydride, a combination of acetic anhydride and butyric anhydride, and a combination of acetic anhydride, propionic anhydride and butyric anhydride.
a combination of acetic anhydride and propionic anhydride, and a combination of acetic anhydride and butyric anhydride are preferable.
Acetic anhydride is more reactive than propionic anhydride and the like, and in the case of obtaining a cellulose mixed fatty acid ester having a low degree of acetyl group substitution, acetic anhydride is not used or the object of the present invention is not impaired.
the esterification solvent having at least 3 carbon atoms and corresponding to the acyl group may be combined with a small amount of acetic anhydride.
the esterification solvent may correspond to an acyl group having 3 or more carbon atoms, for example, propionic anhydride, if acylation or aging can be performed in the presence of acetic acid.
acylation or aging can be performed in the presence of acetic acid.
What is necessary is just to comprise by butyric anhydride etc., and it does not necessarily need to contain the esterification solvent (acetic anhydride) corresponding to an acetyl group.
acetic anhydride is not necessarily used, and the reaction may be carried out in the presence of acetic acid.
Such acetic acid may be present in the reaction system in the esterification step and the ripening step (particularly at least the ripening step), and may be composed only of acetic acid derived from the activation treatment. May be newly added, and may be used as an esterification solvent in an ordinary esterification step.
a plurality of esterification solvents may coexist in the reaction system, and after esterifying cellulose with a specific esterification solvent
the cellulose may be esterified with another esterification solvent.
the amount of the esterification solvent used in the esterification step is, for example, in the range of 1.1 to 4 equivalents, preferably in the range of 1.1 to 2 equivalents, more preferably 1.3 to the hydroxy group of cellulose. It is in the range of about ⁇ 1.8 equivalent.
an esterification solvent organic carboxylic acid such as acetic acid, propionic acid, butyric acid
the amount of esterification solvent (carboxylic acid) used is in the range of 50 to 700 parts by weight, preferably in the range of 150 to 600 parts by weight, and more preferably in the range of 200 to 550 parts by weight with respect to 100 parts by weight of cellulose. Degree.
the esterification reaction can be performed at a temperature in the range of 0 to 50 ° C., preferably in the range of 5 to 45 ° C., more preferably in the range of 10 to 40 ° C.
the esterification reaction may be initially performed at a relatively low temperature of 10 ° C. or lower (0 to 10 ° C.).
the reaction time at such a low temperature may be, for example, 30 minutes or more, 40 minutes to 2 hours, preferably 45 to 100 minutes from the start of the esterification reaction.
the esterification time in the range of 10 to 50 ° C. is in the range of 10 to 20 minutes, preferably in the range of 30 to 80 minutes, and in the range of 40 to 75 minutes.
the hydrolysis reaction may be started, or the esterification solvent, the esterification solvent, and the acid catalyst may be left as they are, and the aging step may be performed.
the quenching agent that promotes hydrolysis may be composed of water and at least one selected from esterification solvents, alcohols, and neutralizing agents. More specifically, examples of the quencher include water alone, a mixture of water and carboxylic acid, a mixture of water and alcohols, a mixture of water and neutralizer, water, organic carboxylic acid and alcohols. And a mixture of a neutralizing agent and the like.
Examples of the neutralizing agent include bases that can neutralize part of the acid catalyst or esterification solvent, such as alkali metal compounds (hydroxides such as sodium hydroxide and potassium hydroxide, carbonates such as sodium carbonate and potassium carbonate, etc. , Organic acid salts such as sodium acetate and potassium acetate), alkaline earth metal compounds (eg, hydroxides such as calcium hydroxide, carbonates such as calcium carbonate, organic acid salts such as calcium acetate and magnesium acetate) And may be used alone or in combination of two or more.
alkali metal compounds hydrooxides such as sodium hydroxide and potassium hydroxide, carbonates such as sodium carbonate and potassium carbonate, etc.
Organic acid salts such as sodium acetate and potassium acetate
alkaline earth metal compounds eg, hydroxides such as calcium hydroxide, carbonates such as calcium carbonate, organic acid salts such as calcium acetate and magnesium acetate
alcohols examples include linear alcohols (ethanol, methanol, propanol, etc.). These alcohols can also be used alone or in combination of two or more.
the ratio of water and esterification solvent or water and alcohol can be selected from the range of about 20 to 140 parts by mass of the esterification solvent or alcohol with respect to 100 parts by mass of water, and is usually in the range of 25 to 120 parts by mass. Of these, preferably in the range of 50 to 100 parts by mass.
a neutralizing agent may be included at a ratio of partially neutralizing the acid catalyst, or a neutralizing agent may not be included.
the preferred deactivator may be water alone, but since water is a poor solvent for cellulose esters, there is a high possibility that cellulose esters other than the desired degree of substitution will precipitate. And a mixed solution is preferable.
reaction component contained in the raw material cellulose is not 100%, an unreacted component is included at this stage, so a step of filtering the reaction solution may be introduced once.
This reaction stopping step can be omitted if necessary.
the solution after completion of the esterification reaction contains unacetylated, low-acetylated components and impurities that did not react with the raw material cellulose.
the time is shortened, and specific cleavage of molecular chains and substituents occurring in the reaction solution is less likely to occur.
the film surface quality of the film formed using the obtained cellulose ester is cellulose without filtration. Even better than the ester.
Filter media used for filtration preferably have low absolute filtration accuracy, but if the absolute filtration accuracy is too low, the filter media is likely to be clogged, and the filter media must be replaced frequently, reducing productivity. There is a problem of making it.
the material of the filter medium is not particularly limited, and a normal filter medium can be used. However, a filter medium made of plastic such as polypropylene, polyester, and PTFE, a filter medium made of glass fiber, and a metal filter medium such as stainless steel fiber can be used. This is preferable because there is no dropout.
the metal filter Since the cellulose ester slurry contains an acid, the metal filter is easily corroded, and therefore, a filter made of glass fiber or plastic fiber is more preferable.
the required amount of acid catalyst may be added again, or used in the aging process without neutralizing the acid catalyst (especially sulfuric acid) used in the esterification process. May be.
An acid catalyst other than the acid catalyst used in the esterification may be added.
the acid catalyst used in the esterification step as it is in the aging step without adding an acid catalyst in the aging step.
the alkali metal or alkaline earth metal contained in the neutralizing agent is added in the neutralizing agent, and remains in the purified cellulose ester. It is preferable not to add sulfuric acid in the aging process because it can be an obstacle.
a deacylation solvent such as a mixed solution of water and carboxylic acid
a deacylation solvent such as a mixed solution of water and carboxylic acid
the reaction temperature during the ripening step is preferably in the range of 20 to 90 ° C, preferably in the range of 25 to 80 ° C, more preferably in the range of 30 to 70 ° C, and the ripening reaction is performed in a nitrogen atmosphere. Or in an air atmosphere.
the aging reaction time can be selected from the range of 20 minutes or more and 25 minutes to 6 hours, preferably 30 minutes to 5 hours, and more preferably 1 to 3 hours.
the reaction product (dope containing cellulose mixed fatty acid ester) is put into a precipitation solvent (water, aqueous acetic acid solution, etc.) to separate the cellulose mixed fatty acid ester, and free metal components and sulfuric acid components are removed by washing with water. May be.
a neutralizing agent can also be used in the case of washing with water.
the post-treatment step is a step after neutralizing the acid catalyst in the neutralization step, and the product is precipitated and precipitated, the precipitated cellulose ester is filtered and separated, and the separated cellulose ester is washed, It preferably comprises a drying step.
a mixed solution of water and carboxylic acid is preferably used, but is not limited to these poor solvents, and ketones, alcohols, ethers, esters and the like alone or in a water mixed solvent There may be.
the cellulose ester production method is most effectively used in the product precipitation step in the post-treatment step for the purpose of reducing the crystallized product. Moreover, you may reduce a crystallized substance by the manufacturing method of the said cellulose ester once using the taken-out cellulose ester.
the method for producing the cellulose ester resin is more preferably combined with a filtration step.
the degree of purification of the cellulose ester resin is further improved by the filtration step.
the combined filtration step is preferably a method of filtering a solution obtained by adding a carboxylic acid to a cellulose ester, either before the start of the acylation step or before the precipitation step.
Various known filtration devices can be used for filtering the cellulose ester solution. That is, it can be divided into a continuous filter and a batch pressure filter when roughly classified as a filter, and as a continuous filter, it can be divided into a belt type, a multiple disk type, a screw press type, a filter press type, etc.
Examples of the batch pressure filter include a leaf type and a candle type.
a filter press device, a paper filter device, a leaf filter device, a drum filter device, a precoat filter device, or the like can be used.
the industrially most advantageous product is a filter press device, and the filter press device may be precoated and used.
the filter press apparatus 40 to 50 plates of about 60 cm square are used, and each plate is provided with a net, and filter paper or cotton cloth is installed between the nets.
a plurality of these filter press apparatuses may be used for filtration in multiple stages.
As the filter medium a sintered metal filter, a non-woven metal filter, a cotton cloth filter, a paper filter, or the like may be used.
the filter medium to be used can be a natural fiber or a synthetic fiber.
polypropylene, polyester (tetron), and nylon can be used as the material of the synthetic fiber used for the filter cloth.
Vinylon, acrylic, saran, etc. can also be used depending on the solvent.
Each of these materials has characteristics on the material and can be used according to the characteristics.
cotton can be mentioned as a typical material.
Monofilaments, multifilaments, spun yarns and the like can be used as the type of raw yarn used for the filter cloth. When a monofilament is used, the cake peelability is excellent and clogging is small, but there is a disadvantage that the fine particles are poorly captured.
the filter cloth weave includes plain weave, twill weave, and satin weave.
plain weave particles are easily collected but clogging is accelerated.
twill weave a filter cloth having a good balance between trapping properties and clogging can be obtained.
satin weaving particles are less clogged, but the ability to collect particles is poor.
a plain weave or twill filter cloth is suitable for the method for producing the cellulose ester.
cotton flannel (No. 10B, 63 plain weave diameter 20 single yarns, 46 weft 10 single yarns), gold width (11, 100 plain weave diameter 40 single yarns, 98 weft 40 single yarns) ), Thick twill (26, twill, 12-3, 64, 12-4, 32) may be used.
filter paper 300 g / m 2 or the like may be used. These filter media may be used in combination (for example, the first filter media is one cotton flannel filter paper, the second filter media is two cotton flannels, one gold width, and the third filter media is one cotton flannel one filter paper, one gold width).
the retention particle size of the filter medium is preferably within the range of 1 to 50 ⁇ m. A range of 2 to 20 ⁇ m is more preferable, and a range of 3 to 15 ⁇ m is most preferable. By using such a filter medium, filterability is improved and productivity is improved.
the pressure in the filtration step can be appropriately set in consideration of the filtration efficiency.
the filter medium may be pressurized within a range of 5 to 18 atmospheres (for example, 8 to 18 atmospheres, for example, 10 to 18 atmospheres).
the shape of the cellulose mixed fatty acid ester composition obtained by dissolving cellulose ester in an organic solvent, filtering and drying may be a filament.
kaolin, titanium oxide, clay, or the like may be used as a filter aid.
the filtrate may be kept warm in the range of 40 to 50 ° C.
the filter medium may be pressurized within a range of 5 to 18 atmospheres (for example, 8 to 18 atmospheres, for example, 10 to 18 atmospheres).
the first filter medium is a cotton flannel 1 filter paper
the second filter medium is a cotton flannel 1 sheet, a gold width 1 sheet
the third filter medium is a cotton flannel 1 sheet of filter paper 1 sheet of a gold width 1 sheet
the first filtration is performed within the range of 12 to 18 atm
the second filtration is performed within the range of 8 to 14 atm
the third filtration is performed within the range of 5 to 9 atm. May be.
the filtration pressure may be changed between the first time and the second time (for example, the second filtration is performed at a lower pressure).
the retained particle size of the filter used for filtration is preferably in the range of 1 to 30 ⁇ m, more preferably in the range of 1 to 20 ⁇ m, and still more preferably in the range of 2 to 20 ⁇ m.
the retained particle size of the filter By setting the retained particle size of the filter to 0.1 ⁇ m or more, it tends to be able to suppress a significant increase in the filtration pressure, and industrial production is also facilitated. Further, by setting the retained particle size to 30 ⁇ m or less, fine foreign matters can be removed, and therefore it is effective when combined with the precipitation step. Further, filtration may be performed by combining filters having different retention particle sizes.
the temperature at the time of filtration can be any temperature as long as filtration is possible, but it is preferably in the range of 30 to 100 ° C., more preferably in the range of 35 to 80 ° C., still more preferably 40 Heating in the range of ⁇ 70 ° C. is preferable because the viscosity of the solution can be lowered.
the filtration pressure is preferably within the range of 0.001 to 10 MPa, more preferably within the range of 0.001 to 5 MPa, and even more preferably within the range of 0.01 to 1 MPa.
celite for example, Filter-Cel, Celite 505, Standard Super-Cel, Celite 512, Hyflo Super-Cel, manufactured by Johns-Manville Sales Corp.
Dicalite Superref, Specified Flow, Special Spec, made by Glefco, Inco, USA, Inc.
radio lights (RADIOLITE # manufactured by Showa Chemical Industry Co., Ltd.) 00, RADIOLITE # 200, RADIOLITE # 500, RADIOLITE # 600, RADIOLITE # 700, RADIOLITE # 900, RADIOLITE # 1100, RADIOLITE # 100), layered clay mineral (preferably talc, mica, kaolinite), silicon dioxide fine particles (for example, silicon dioxide fine particles (for example, silica gel MB-300, MB-500 manufactured by Fuji Silysia Co., Ltd., Fuji silica gel AB type, Fuji silica gel A type, Fuji silica gel RD type, BW-25K, Merck Silica Gel 40, (Silica Gel 60, Silica Gel 100, etc.) etc.
These filter aids may be mixed with a cellulose ester solution and subjected to cake filtration. Pre-coated on the solution may be filtered cellulose ester is dissolved.
the content of the alkali metal or the Group 2 element in the cellulose ester is preferably in the range of 1 to 150 ppm, respectively, from the viewpoint of generating a high molecular weight substance and reducing gelled foreign matter.
content of an alkali metal or a Group 2 element means the total of the mass in terms of the atom of the alkali metal or Group 2 element contained in a cellulose ester.
the content of the alkali metal or group 2 element in the cellulose ester can be controlled within the range of 1 to 100 ppm by mass in terms of reducing surface roughness and reducing gelled foreign matter. More preferably, each is in the range of 1 to 50 ppm by mass.
the content of alkali metal or group 2 element in the cellulose ester can be measured by the following method.
the cellulose ester contained in a film is extracted.
the content of the alkali metal or the Group 2 element in the cellulose ester can be measured by the following atomic absorption method.
(1) Immerse the washed 50 ml capacity magnetic crucible in 2N aqueous nitric acid solution overnight.
(2) A magnetic crucible soaked in 2N nitric acid is washed with pure water, rinsed with ultrapure water, and dried in a drier.
a 2 g film sample is precisely weighed in a magnetic crucible.
the calibration curve was created by the following method.
the standard solution for the calibration curve was prepared by diluting a commercially available standard solution for atomic absorption (manufactured by Wako Pure Chemical Industries, Ltd.) with 0.1N hydrochloric acid aqueous solution to a concentration of 0.1, 0.75, 1.5 ppm. used.
a trade name “AA-680” manufactured by Shimadzu Corporation was used as the atomic absorption device.
the alkali metal is at least one selected from the group consisting of Li, Na, K, Rb, Cs, and Fr. Among these, at least one selected from the group consisting of Li, Na, and K is preferable from the viewpoint of suppressing coloring during heating, and more preferably K is included.
the group 2 element is at least one selected from the group consisting of Be, Mg, Ca, Sr, Ba, and Ra. Among them, at least one selected from the group consisting of Mg and Ca is preferable from the viewpoint of suppressing coloring during heating, and more preferably Mg is included.
alkali metals and Group 2 elements may be used singly or in combination of two or more. Moreover, you may use together an alkali metal and a Group 2 element. When used in combination, the content is the total amount of all alkali metals and Group 2 elements contained in the film.
the alkali metal or Group 2 element is present in the film as a monovalent or divalent metal ion, or in the form of an inorganic salt or an organic fatty acid salt.
the inorganic salt include alkali metal or group 2 element halides, hydroxides, oxides, sulfates, nitrates, silicates, and the like.
natural products for example, talc (Mg 3 Si 4 O 10 (OH) 2 ), etc.
the organic fatty acid salt include acetate, citrate, maleate and the like.
an inorganic salt or metal ion such as Li, Na, K, Mg, Ca, etc.
the method for adjusting the content of the alkali metal or the Group 2 element in the cellulose ester resin is not particularly limited.
a desired amount of organic fatty acid salt or inorganic is added to the cellulose ester resin from which salt is removed or a resin composition containing the same. It can be adjusted by adding (adding) a salt.
cleaning water in the manufacturing process of a cellulose-ester resin instead of adding salt directly is mentioned.
Adjust the amount of salt to be added ; perform partial addition instead of adding all at once (repeat partial neutralization in the aging step (neutralize by adding a base continuously or intermittently)); Adjust the content of the metal contained in the cellulose ester resin by adjusting the amount of the recovered and recycled product used; or by selecting pure water adjusted for each ion amount and repeating washing; The content of the group element can be set to a desired range.
the content mass ratio of the acrylic resin and the cellulose ester resin is such that the acrylic resin: cellulose ester resin has a mass ratio of 95: 5 to 30:70. This is necessary from the viewpoint of improving the heat resistance of the film, and is preferably in the range of 70:30 to 60:40.
the content ratio of the acrylic resin is within the above range, the characteristics of the cellulose ester resin can be sufficiently obtained, and the resulting film has a low brittleness and a small photoelastic coefficient.
the resin composition described above may further contain optional components such as an ultraviolet absorber, an antioxidant, a plasticizer, a retardation control agent, and fine particles as necessary. Good.
the ultraviolet absorber is a compound that absorbs ultraviolet rays having a wavelength of 400 nm or less, preferably a compound having a transmittance at a wavelength of 370 nm of 10% or less, more preferably 5% or less, and even more preferably 2% or less.
the light transmittance of the ultraviolet absorber can be measured with a spectrophotometer by a conventional method using a solution obtained by dissolving the ultraviolet absorber in a solvent (for example, dichloromethane, toluene, etc.).
the spectrophotometer is, for example, a spectrophotometer UVIDFC-610 manufactured by Shimadzu Corporation, a 330-type self-recording spectrophotometer, a U-3210-type self-recording spectrophotometer, a U-3410-type self-recording spectrophotometer, manufactured by Hitachi, Ltd. -4000 self-recording spectrophotometer or the like can be used.
the ultraviolet absorber may be an oxybenzophenone compound, a benzotriazole compound, a salicylic acid ester compound, a benzophenone compound, a cyanoacrylate compound, a triazine compound, a nickel complex salt compound, an inorganic powder, etc.
benzotriazole-based UV absorbers and benzophenone-based UV absorbers are preferable, and benzotriazole-based UV absorbers are more preferable.
ultraviolet absorbers include 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl)- 6- (Linear and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, Tinuvin 109, Tinuvin 171, Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin Tinuvins such as 328 and Tinuvin 928 (manufactured by BASF Japan Ltd.) are included.
the content of the ultraviolet absorber depends on the type of the ultraviolet absorber, but is preferably in the range of 0.5 to 10% by mass, and in the range of 0.6 to 4% by mass with respect to the optical film. More preferably.
the resin composition according to the present invention preferably further contains an antioxidant as a stabilizer.
antioxidants include phenolic compounds, hindered amine compounds, phosphorus compounds, compounds containing unsaturated double bonds, and the like.
examples of the phenolic compound include a compound having a 2,6-dialkylphenol structure (for example, 2,6-di-t-butyl-p-cresol).
examples of commercially available phenolic compounds include Irganox 1076, Irganox 1010, manufactured by BASF Japan Ltd., and Adeka Stub AO-50, manufactured by ADEKA Corporation.
Examples of phosphorus compounds include tris (2,4-di-t-butylphenyl) phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-diphosphite, and the like.
Examples of commercially available phosphorus compounds include Sumitizer GP manufactured by Sumitomo Chemical Co., Ltd., ADK STAB PEP-24G manufactured by ADEKA Co., Ltd., ADK STAB PEP-36 and ADK STAB 3010, IRGAFOS P-EPQ manufactured by BASF Japan K.K. This includes GSY-P101 manufactured by Kogyo Corporation.
hindered amine compounds examples include Tinuvin 144 and Tinuvin 770 manufactured by BASF Japan Ltd., ADK STAB LA-52 manufactured by ADEKA Corp., and the like. These antioxidants may be only one kind or a mixture of two or more kinds.
Examples of the compound containing an unsaturated double bond include Sumitizer GM and Sumilizer GS manufactured by Sumitomo Chemical Co., Ltd.
the content of the antioxidant is preferably in the range of 1 ppm to 2.0% by mass relative to the resin component, more preferably 10 ppm to 1.0%, and more preferably 10 ppm to 0.1%. More preferably, it is within the range.
the fine particles have a function of increasing the slipperiness of the surface of the obtained optical film.
the fine particles may be inorganic fine particles or organic fine particles.
examples of the inorganic fine particles include silicon dioxide and zirconium oxide, and silicon dioxide is particularly preferable in order to reduce an increase in the haze of the film.
silicon dioxide examples include Aerosil 200V, Aerosil R972V, Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600, NAX50 (manufactured by Nippon Aerosil Co., Ltd.), Sea Hoster KEP-10, Sea Hoster KEP- 30, Seahoster KEP-50 (above, manufactured by Nippon Shokubai Co., Ltd.), Silo Hovic 100 (manufactured by Fuji Silysia), Nip Seal E220A (manufactured by Nippon Silica Industry), Admafine SO (manufactured by Admatechs), and the like.
the shape of the fine particles is irregular, acicular, flat or spherical, and is preferably spherical in order to ensure the transparency of the resulting film.
the size of the primary particles of fine particles or aggregates thereof is preferably in the range of 80 to 180 nm in order to obtain sufficient slipperiness.
the size of the primary particles of the fine particles or the aggregates thereof can be obtained as an average value of the particle diameters of 100 particles by observing the particles with a transmission electron microscope at a magnification of 500 to 2 million times.
the content of the fine particles is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 1.0% by mass with respect to the resin component described above. When the content of the fine particles is more than 5.0% by mass, aggregates can be reduced.
FIG. 5 is a diagram schematically showing the steps of the melt casting film forming method preferable for the present invention.
the manufacturing method of the optical film of the present invention is such that after mixing film materials such as acrylic resin and cellulose ester resin, the extruder 1 is used to melt and extrude from the casting die 4 onto the first cooling roller 5.
the film is further circumscribed by a total of three cooling rollers, the second cooling roller 7 and the third cooling roller 8, in order to cool and solidify the film 10.
the film 10 peeled by the peeling roller 9 is then stretched in the width direction by gripping both ends of the film by the stretching device 12 and then wound by the winding device 16.
an elastic touch roller 6 that clamps the molten film on the surface of the first cooling roller 5 is provided to correct the flatness.
the elastic touch roller 6 has an elastic surface and forms a nip with the first cooling roller 5.
Extruder 1 is a melt-kneading extruder, and has a cylinder and a screw rotatably provided therein.
a hopper (not shown) for supplying film material is provided at the supply port of the cylinder.
the shape of the screw may be full flight, mudock, dull mage, etc., and is selected according to the viscosity of the molten resin and the required shearing force.
the extruder 1 may be a single screw extruder or a twin screw extruder.
a filter 2 for filtering the molten resin may be further provided between the extruder 1 and the casting die 4.
the filter 2 can be, for example, a leaf disk type filter.
the filtration accuracy of the filter is preferably 3 to 15 ⁇ m.
the material of the filter may be stainless steel or a sintered product thereof.
a mixing device such as a static mixer 3 for uniformly mixing the resin, a gear pump (not shown) for stabilizing the extrusion flow rate, and the like are further provided. Also good.
the casting die 4 may be a known one, such as a T die.
the material of the casting die 4 can be hard chrome, chromium carbide or the like.
the lip clearance of the casting die 4 is preferably 900 ⁇ m or more, and more preferably in the range of 1 to 2 mm.
the inner wall surfaces of the extruder 1 and the casting die 4 are preferably subjected to surface processing for reducing the surface roughness or reducing the surface energy in order to make the molten resin difficult to adhere.
surface processing include processing for polishing to have a surface roughness of 0.2 S or less after hard chrome plating or ceramic spraying.
the cooling rollers 5, 7 and 8 are high-rigidity metal rollers and have a structure in which a temperature-controllable medium can be circulated.
the surface material of the cooling rollers 5, 7, and 8 can be stainless steel, aluminum, titanium, or the like.
the surface of the cooling rollers 5, 7 and 8 may be subjected to a surface treatment such as hard chrome plating in order to facilitate the peeling of the resin.
the arithmetic average roughness Ra of the surfaces of the cooling rollers 5, 7 and 8 is preferably 0.1 ⁇ m or less, and more preferably 0.05 ⁇ m or less in order to keep the haze of the resulting film low.
the elastic touch roller 6 is disposed to face the cooling roller 5.
the molten resin extruded from the casting die 4 is nipped between the cooling roller 5 and the elastic touch roller 6.
the stretching apparatus 12 is not particularly limited, but a roller stretching machine, a tenter stretching machine, or the like is preferably used. A roller stretching machine and a tenter stretching machine may be combined.
the tenter stretching machine preferably has a preheating zone, a stretching zone, a holding zone, and a cooling zone, and preferably has a neutral zone for insulating between the zones.
the optical film is, for example, a step of preparing pellets made of the resin composition described above (pelletizing step); a step of melt-kneading the film material containing the pellets with the extruder 1 and then extruding from the casting die 4 (melt extrusion) Step); a step of obtaining a film by cooling and solidifying the extruded molten resin (cooling and solidification step); and a step of stretching the film (stretching step).
the resin composition containing the acrylic resin and cellulose ester is preferably kneaded and pelletized in advance.
Pelletization can be performed by a known method.
the above resin composition is melt-kneaded with an extruder and then extruded from a die in a strand shape.
the molten resin extruded in a strand form can be cooled with water or air, and then cut to obtain pellets.
the raw material of the pellet is preferably dried before being supplied to the extruder 1 in order to prevent decomposition.
the cellulose ester easily absorbs moisture, it is preferable to dry it at 70 to 140 ° C. for 3 hours or more so that the water content is 200 ppm or less, preferably 100 ppm or less.
the mixture of the antioxidant and the resin component may be mixed with each other; the antioxidant dissolved in the solvent may be impregnated with the resin component; and the antioxidant may be mixed with the resin.
the ingredients may be sprayed and mixed.
a vacuum nauter mixer or the like is preferable because the raw materials can be dried and mixed at the same time.
the atmosphere in the vicinity of the hopper of the extruder 1 and in the vicinity of the exit of the casting die 4 is preferably an atmosphere of dehumidified air or N 2 gas in order to prevent deterioration of the raw material of the pellet.
the extruder 1 it is preferable to knead at a low shearing force or at a low temperature so as not to cause deterioration of the resin (decrease in molecular weight, increase in coloration, generation of high molecular weight bodies or gel-like foreign matters, etc.).
a twin-screw extruder it is preferable to use a deep groove type screw and to rotate the two screws in the same direction.
two screw shapes mesh with each other.
an optical film may be produced by melting and kneading the resin composition that has not been melt-kneaded as a raw material in the extruder 1 as it is.
the obtained molten pellets and other additives as required are fed from the hopper to the extruder.
the supply of pellets is preferably performed under vacuum, reduced pressure, or inert gas atmosphere in order to prevent oxidative decomposition of the pellets.
the film material containing the molten pellet is melt-kneaded.
the melting temperature of the film material in the extruder 1 depends on the type of the film material, it is preferably in the range of Tg to (Tg + 100) ° C., more preferably when the glass transition temperature of the film is Tg. It is within the range of (Tg + 10) to (Tg + 90) ° C.
the residence time of the film material in the extruder 1 is preferably 5 minutes or less. The residence time can be adjusted by the number of rotations of the screw, the depth of the groove, L / D which is the ratio of the cylinder length (L) to the cylinder inner diameter (D), and the like.
the molten resin extruded from the extruder 1 is filtered with a filter 2 or the like as necessary, and further mixed with a static mixer 3 or the like, and extruded from a casting die 4 into a film.
the melting temperature Tm of the resin at the exit portion of the casting die 4 can be about 200 to 300.degree.
the resin extruded from the die is nipped between the cooling roller 5 and the elastic touch roller 6 so that the film-like molten resin has a predetermined thickness. Then, the film-like molten resin is cooled stepwise with a plurality of cooling rollers 7 and 8 and solidified.
the surface temperature Tr1 of the cooling roller 5 can be Tg or less, where Tg is the glass transition temperature of the resulting film.
the surface temperature Tr2 of the second cooling roller 7 can be (Tg ⁇ 50) ° C. ⁇ Tr2 ⁇ Tg ° C.
the film surface temperature Tt on the elastic touch roller 6 side can be (Tr1-50) ° C. ⁇ Tt ⁇ (Tr1-5) ° C.
the film-shaped molten resin solidified by the cooling rollers 5, 7 and 8 is peeled by the peeling roller 9 to obtain a web.
the obtained web is stretched by the stretching device 12 to obtain a film.
the stretching may be performed in at least one direction, and is preferably performed in both the web width direction (TD direction) and the web conveyance direction (MD direction).
the web width direction (TD direction) stretching and the web conveyance direction (MD direction) stretching are sequential. Or may be performed simultaneously.
the draw ratio may be 1.01 to 3.0 times, preferably 1.1 to 2.0 times in each direction.
the final direction is 1.01 to 3.0 times, preferably 1.1 to 2.0 times in each direction. It is preferable to do.
the stretching temperature is preferably Tg to (Tg + 50) ° C.
the stretching temperature is preferably uniform in the width direction of the web (TD direction) or the transport direction (MD direction), and the variation in the width direction or transport direction of the web stretching temperature is preferably ⁇ 2 ° C. or less,
the temperature is more preferably ⁇ 1 ° C. or less, and further preferably ⁇ 0.5 ° C. or less.
the film obtained after stretching is shrunk in the transport direction (MD direction) or the width direction (TD direction) as necessary. May be.
MD direction transport direction
TD direction width direction
the width of the obtained optical film is preferably in the range of 1.3 to 4 m, and more preferably in the range of 1.4 to 3.0 m.
the total content of the acrylic resin and the cellulose ester resin in the obtained optical film is preferably 55% by mass or more, more preferably 60% by mass or more, and 70% by mass or more with respect to the optical film. More preferably.
the weight average molecular weight Mw is not more than a certain value, and the content of residual components such as unreacted monomers, radical polymerization initiators or chain transfer agents is adjusted to be not more than a certain amount. Therefore, the production of a high molecular weight resin can be reduced when the acrylic resin and the cellulose ester resin are melt-kneaded. Therefore, even if the optical film is a thin film, surface roughness does not occur.
the thickness of the optical film is not particularly limited, but is preferably in the range of 10 to 35 ⁇ m, more preferably in the range of 10 to 30 ⁇ m, and in the range of 15 to 25 ⁇ m It is particularly preferable for providing a film.
the retardation value Ro in the in-plane direction of the optical film is preferably in the range of 0 to 100 nm, and more preferably in the range of 0 to 250 nm.
the retardation value Rt in the thickness direction is preferably in the range of ⁇ 100 to 100 nm, and more preferably in the range of ⁇ 50 to 50 nm.
the retardation value can be adjusted by, for example, the content ratio of acrylic resin and cellulose ester, stretching conditions, and the like.
Retardation values Ro and Rt are represented by the following formulas, respectively.
Formula (I) Ro (n x -n y) ⁇ d
Formula (II) Rt ⁇ (n x + n y ) / 2 ⁇ n z ⁇ ⁇ d
N x the slow axis direction of the refractive index of the film plane
n y the film plane, the refractive index in the direction perpendicular to the slow axis
n z refractive index of the film in the thickness direction
d Film thickness (nm)
the retardation values Ro and Rt can be determined by the following method, for example.
the average refractive index of the film is measured with a refractometer.
⁇ is greater than 0 °, preferably in the range of 30 ° to 50 °.
nx, ny and nz are calculated by KOBRA-21AWR manufactured by Oji Scientific Instruments, and Rt is calculated.
the angle ⁇ 1 (orientation angle) formed by the in-plane slow axis of the optical film and the width direction of the film is preferably ⁇ 5 ° or more and + 5 ° or less, and more preferably ⁇ 1 ° or more and + 1 ° or less. .
the orientation angle ⁇ 1 of the optical film can be measured using an automatic birefringence meter KOBRA-21AWR (Oji Scientific Instruments).
the haze of the optical film measured in accordance with JIS K-7136 is preferably less than 1.0%, more preferably 0.2% or less, and 0.1% or less. More preferably, it is particularly preferably 0.05% or less.
the amount of residual components contained in the acrylic resin is set to a certain level or less, and the generation of gel-like foreign matters is suppressed by using a purified cellulose ester resin preferable for the present invention. Is preferred.
the haze of the optical film can be measured by a method based on JIS K-7136; specifically, the following method can be used.
the obtained optical film is conditioned at a temperature of 23 ° C. and a relative humidity of 55% RH for 5 hours or more. Thereafter, dust attached to the surface of the film is removed with a blower or the like.
the haze of the optical film is measured with a haze meter (turbidimeter) (model: NDH 2000, manufactured by Nippon Denshoku Industries Co., Ltd.) under the condition of 23 ° C. and 55% RH.
the light source of the haze meter may be a 5V9W halogen sphere, and the light receiving part may be a silicon photocell (with a relative visibility filter).
the total light transmittance of the optical film is preferably 90% or more, and more preferably 93% or more.
the total light transmittance can be measured with a spectrophotometer.
the spectrophotometer is, for example, a spectrophotometer UVIDFC-610 manufactured by Shimadzu Corporation, a 330-type self-recording spectrophotometer, a U-3210-type self-recording spectrophotometer, a U-3410-type self-recording spectrophotometer, manufactured by Hitachi, Ltd. -4000 self-recording spectrophotometer or the like can be used.
the glass transition temperature of the optical film is preferably in the range of 110 to 200 ° C, and more preferably in the range of 120 to 190 ° C.
the glass transition temperature of the optical film can be measured by a method based on JIS K7121 (1987). Specifically, using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer), the glass transition temperature (Tmg) when the optical film was heated at a heating rate of 20 ° C./min. Can be measured as
the moisture permeability of the optical film at 40 ° C. and 90% RH measured in accordance with JIS Z 0208 is preferably in the range of 200 to 1500 (g / (m 2 ⁇ 24 hr)), and is preferably 400 to 1200 ( g / (m 2 ⁇ 24 hr)) is more preferable.
the content ratio of the acrylic resin may be increased.
the optical film of the present invention is suitable for bonding to a polarizer to produce a polarizing plate.
a polarizer is an element that allows only light having a polarization plane in a certain direction to pass therethrough.
a typical example of the polarizer is a polyvinyl alcohol-based polarizing film, and there are one in which a polyvinyl alcohol-based film is dyed with iodine and one in which a dichroic dye is dyed.
the polarizer may be a film obtained by uniaxially stretching a polyvinyl alcohol film and then dyeing with iodine or a dichroic dye, or after dyeing a polyvinyl alcohol film with iodine or a dichroic dye, A uniaxially stretched film (preferably a film further subjected to durability treatment with a boron compound) may be used.
the thickness of the polarizer is preferably in the range of 5 to 30 ⁇ m, more preferably in the range of 10 to 20 ⁇ m.
the polyvinyl alcohol film may be a film formed from a polyvinyl alcohol aqueous solution.
the polyvinyl alcohol film is preferably an ethylene-modified polyvinyl alcohol film because it is excellent in polarizing performance and durability performance and has few color spots.
Examples of the ethylene-modified polyvinyl alcohol film include an ethylene unit content of 1 to 4 mol%, a degree of polymerization of 2000 to 4000, and a degree of saponification of 99 described in JP-A Nos. 2003-248123 and 2003-342322. 0.0-99.99 mol% film is included.
dichroic dyes examples include azo dyes, stilbene dyes, pyrazolone dyes, triphenylmethane dyes, quinoline dyes, oxazine dyes, thiazine dyes and anthraquinone dyes.
the optical film of the present invention may be disposed directly on at least one surface of the polarizer, or may be disposed via another film or layer.
a protective film (other protective film) other than the optical film of the present invention may be disposed on the other surface of the polarizer.
Other protective films are not particularly limited, and may be ordinary cellulose ester films and the like.
cellulose ester films examples include commercially available cellulose ester films (for example, Konica Minoltak KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC4UY, KC4UY, CC6UY KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UAKC, 2UAH, KC4UAH, KC6UAH, and above, manufactured by Konica Minolta Advanced Layer Co., Ltd.) are preferably used.
cellulose ester films for example, Konica Minoltak KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC
the polarizing plate can be usually obtained through a step of bonding a polarizer and the above-described optical film.
a completely saponified polyvinyl alcohol aqueous solution or the like is preferably used.
the optical film of the present invention and the polarizer can be bonded together using an active energy ray-curable adhesive or the like, but the resulting adhesive layer has a high elastic modulus and deforms the polarizing plate. From the viewpoint of easy suppression, it is preferable to use a photocurable adhesive.
Preferred examples of the photocurable adhesive include ( ⁇ ) cationic polymerizable compound, ( ⁇ ) photocationic polymerization initiator, and ( ⁇ ) a wavelength longer than 380 nm, as disclosed in JP 2011-08234 A. And a photo-curable adhesive composition containing each component of a photosensitizer exhibiting maximum absorption in the light of ( ⁇ ) and a naphthalene-based photosensitization aid.
other photocurable adhesives may be used.
the polarizing plate includes (1) a pretreatment step for easily adhering the surface of the optical film to which the polarizer is bonded, and (2) at least one of the adhesive surfaces of the polarizer and the optical film. (3) A bonding step of bonding the polarizer and the optical film through the obtained adhesive layer, and 4) A polarizer and the optical film are bonded through the adhesive layer. It can manufacture by the manufacturing method including the hardening process which hardens an adhesive bond layer in the match
Pretreatment process In the pretreatment step, an easy adhesion treatment is performed on the adhesive surface of the optical film with the polarizer.
easy adhesion processing is performed on the bonding surface of each optical film with the polarizer. Examples of the easy adhesion treatment include corona treatment and plasma treatment.
the photocurable adhesive is applied to at least one of the adhesive surfaces of the polarizer and the optical film.
the application method is not particularly limited. For example, various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.
various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.
the method of pressurizing with a roller etc. and spreading uniformly can also be utilized.
Bonding process For example, when a photocurable adhesive is applied to the surface of the polarizer in the previous application step, an optical film is superimposed thereon. When a photocurable adhesive is applied to the surface of the optical film in the previous application step, a polarizer is superimposed thereon. In addition, when a photocurable adhesive is cast between the polarizer and the optical film, the polarizer and the optical film are superposed in that state.
the optical film is superimposed on the both surfaces of the polarizer via the photocurable adhesive.
both sides if the optical film is superimposed on one side of the polarizer, the polarizer side and the optical film side, and if the optical film is superimposed on both sides of the polarizer, The film is pressed with a roller or the like from the film side).
the material of the roller metal, rubber or the like can be used.
the rollers arranged on both sides may be made of the same material or different materials.
the active energy ray is irradiated to the uncured photocurable adhesive to cure the adhesive layer containing the epoxy compound or the oxetane compound.
the overlapped polarizer and the optical film are bonded via the photocurable adhesive.
an active energy ray is applied from either one of the optical films in a state where the optical film is superimposed on both surfaces of the polarizer via a photocurable adhesive. It is advantageous to irradiate and simultaneously cure the photocurable adhesive on both sides.
active energy rays visible rays, ultraviolet rays, X-rays, electron beams and the like can be used, and since they are easy to handle and have a sufficient curing rate, electron beams or ultraviolet rays are generally preferably used.
the acceleration voltage is preferably in the range of 5 to 300 kV, more preferably in the range of 10 to 250 kV.
the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and may be insufficiently cured.
the acceleration voltage exceeds 300 kV, the penetrating force through the sample is too strong and the electron beam rebounds, and an optical film or polarized light. There is a risk of damaging the child.
the irradiation dose is in the range of 5 to 100 kGy, more preferably in the range of 10 to 75 kGy.
the adhesive becomes insufficiently cured, and when it exceeds 100 kGy, the transparent optical film and the polarizer are damaged, resulting in a decrease in mechanical strength and yellowing, thereby obtaining predetermined optical characteristics. I can't.
Arbitrary appropriate conditions can be employ
the dose of ultraviolet rays in the range of 50 ⁇ 1500mJ / cm 2 in accumulated light amount, and even more preferably in the range of within the range of 100 ⁇ 500mJ / cm 2.
the liquid crystal display device includes a liquid crystal cell and a pair of polarizing plates that sandwich the liquid crystal cell. And at least one is a polarizing plate which has the optical film of this invention among a pair of polarizing plates, More preferably, both of a pair of polarizing plates are polarizing plates which have the optical film of this invention.
the display method of the liquid crystal cell is not particularly limited, and is a TN (Twisted Nematic) method, an STN (Super Twisted Nematic) method, an IPS (In-Plane Switching) method, an OCB (Optically Compensated Birefringence Ventilation method).
TN Transmission Nematic
STN Super Twisted Nematic
IPS In-Plane Switching
OCB Optically Compensated Birefringence Ventilation method.
MVA Multi-domain Vertical Alignment and PVA; including Patterned Vertical Alignment), HAN (Hybrid Aligned Nematic), etc.
the IPS system is preferable, and from the viewpoint of high contrast, the VA system is preferable.
MMA Asahi Kasei Chemicals Corporation Acryloylmorpholine (ACMO): manufactured by Kojin Co., Ltd.
ACMO Acryloylmorpholine
Synthesis Example 1 An acrylic resin was synthesized according to the flow shown in FIG. 4 using the monomer material described above. That is, as shown in FIG.
MMA methyl methacrylate
ACMO acryloylmorpholine
a refrigerant was adjusted through the jacket so that the temperature in the catalyst dissolution tank was 5 ° C.
the obtained catalyst solution was continuously fed to a 10 L polymerization reactor (SUS304, with a helical ribbon blade agitator, with a jacket) at a flow rate of 1.47 kg / Hr by a pump.
MMA methyl methacrylate
ACMO acryloylmorpholine
MMA 88.8 mass%
ACMO 11.2 mass.
the n-octyl mercaptan as a chain transfer agent was further added to 0.137% by mass with respect to the total amount of monomer components contained in the catalyst solution and the monomer mixture. These components were mixed with stirring.
the refrigerant was adjusted through the jacket so that the temperature in the monomer preparation tank was 5 ° C.
the obtained monomer mixed solution was fed to the aforementioned polymerization reactor by a pump at a flow rate of 13.279 kg / hr.
the catalyst solution and the monomer mixture are added, and the polymerization reaction is carried out at an average residence time of 26 minutes at a temperature of 175 ° C. ⁇ 2 ° C. until an average polymerization rate of 56% by mass.
a liquid polymer composition was obtained. Thereafter, the obtained liquid polymer composition was taken out from the upper part of the polymerization reactor and fed to a heater (inner diameter 16.7 mm ⁇ length 3 m, with jacket).
the obtained polymer composition was fed to a devolatilizing extruder while heating the liquid polymer composition to 20 kg / cm 2 G and 200 ° C. in a heater.
the devolatilizing extruder is a twin screw extruder (TEX-30) manufactured by Nippon Steel Co., Ltd., different direction rotation method, screw diameter 30 mm, cylinder length 1200 mm, 1 rear vent, 3 fore vents. Using. Each vent of the devolatilizing extruder was evacuated, the cylinder temperature was about 250 ° C., the liquid polymer composition was devolatilized, and volatile components mainly composed of unreacted monomers were taken out from the vent.
the taken-out unreacted monomer was recovered in a monomer recovery tower (inner diameter 100 mm, length 3 m, SUS304, 3/8 inch SUS Raschig ring packed tower, concentration section length 0.7 m, recovery section length 0.3 m).
acrylic resin A1 was obtained at an average rate of 13.5 kg / hr.
the contents of the monomer, polymerization initiator and chain transfer agent remaining in the obtained acrylic resin A1 were measured by the following method. That is, 0.1 g of acrylic resin was dissolved in 2 ml of acetone and sonicated for 30 minutes. To this solution, 50 ppm of ethylene glycol monomethyl ether as an internal standard component was added, and then diluted to 10 ml with hexane to obtain a sample solution. The contents of the monomer, polymerization initiator, and chain transfer agent contained in this sample solution were measured by GC / MS. The GC / MS measurement apparatus and measurement conditions were as follows.
the acrylic resin A2 tried to reduce the content of residual unreacted monomer to 50 ppm, but it was difficult to reduce it.
the acrylic resin A7 tried to reduce the content of the residual polymerization initiator to 5 ppm, but it was difficult to reduce.
the acrylic resin A22 tried to reduce the content of residual unreacted monomer to 50 ppm, the content of residual polymerization initiator to 5 ppm, and the content of residual chain transfer agent to 5 ppm, but it was difficult to reduce.
(B) Cellulose Ester Resin Table 2 shows the acetyl group substitution degree, propionyl group substitution degree, butyryl group substitution degree, and weight average molecular weight (Mw) of raw material cellulose esters A to E used in the synthesis of the following cellulose ester resins.
the cellulose ester of Table 2 was purchased or synthesize
Table 4 shows the poor solvent, the dropping temperature, the dropping time, and the stirring time.
SP value numerical value s and a value The SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent shown in Tables 3 and 4 was determined from Polymer Hand Book (Second Edition) Chapter IV, Solubility Parameter Values, and the value was taken as s.
Formula (1) a s + 0.8t (In the formula, s is the SP value of the whole solvent after mixing the cellulose ester solution and the poor solvent, and t is the total number of acyl group carbon atoms per glucose unit of the cellulose ester. 0.8t above) Is a term relating to the contribution of the acyl group to the SP value.)
the a value preferably satisfies the following formula (2) for controlling the crystallized product shape.
Alkali metal or Group 2 element content The type and content of alkali metal and the type and content of Group 2 element were measured by the above methods. The results are shown in Table 5.
the obtained pellets were dried by circulating dehumidified air at a temperature of 70 ° C. for 5 hours or more, and then put into a single screw extruder while maintaining the temperature at 100 ° C.
the moisture content of the pellets charged into the single screw extruder was 120 ppm.
the obtained pellets were melt-kneaded at 235 ° C. with a single screw extruder (extruder 1), and then extruded from the T die (die 4) onto the cooling roller 5 having a surface temperature of 90 ° C. And after pressing the resin extruded on the cooling roller 5 with the elastic touch roller 6 whose surface metal layer has a thickness of 2 mm, the resin is further cooled with the cooling roller 7 and the cooling roller 8 to have a thickness of 60 ⁇ m. Got the web.
the cooled and solidified web was peeled off by the peeling roller 9 and then stretched by a roller stretching machine at 175 ° C. in the web conveyance direction (MD direction) at a stretching ratio of 1.6 times (60%).
the obtained film was introduced into a tenter stretching machine having a preheating zone, a stretching zone, a holding zone, and a cooling zone, and further having a neutral zone between each zone. And it extended
Examples 2 to 13 In the same manner as in Example 1, except that the content of the residual unreacted monomer, the residual polymerization initiator, and the residual chain transfer agent in the acrylic resin A1 was changed to the acrylic resin type as shown in Table 6. A film was obtained.
Example 14 to 18 An optical film was obtained in the same manner as in Example 1 except that the type of cellulose ester resin was changed as shown in Table 6.
Example 19 An optical film was obtained in the same manner as in Example 1 except that the thickness of the optical film was changed as shown in Table 6.
Comparative Examples 1 to 5 An optical film of a comparative example was obtained in the same manner as in Example 1 except that acrylic resins A6, A10, A14, and A17 containing a large amount of residual unreacted monomer, residual polymerization initiator, and residual chain transfer agent were used. .
an optical film of a comparative example was obtained in the same manner as in Example 1 except that acrylic resin A16 in which the composition ratio (mass%) of MMA and ACMO was changed to 30:70 was used.
a resin composition containing acrylic resin and cellulose ester resin as a sample in a mass ratio of 65:35 is a thermal analyzer manufactured by SII (EXSTAR6000 TG / DTA). The sample was melted by heating for about 1 hour while keeping the temperature at 260 ° C. in a nitrogen stream using about 5 to 10 mg of the sample.
the molecular weight was measured by the following GPC.
GPC measurement conditions are as follows.
the detection sensitivity value difference obtained by subtracting the detection sensitivity value of GPC before heating and melting from the detection sensitivity value of GPC after heating and melting is plotted against the horizontal axis molecular weight (Mw).
the positive differential area (a) was defined as the area on the high molecular weight side from the molecular weight value indicating the GPC detection sensitivity peak value before heating of the resin composition.
the area was obtained using a multi-station GPC-8020 model II manufactured by Tosoh Corporation.
the high molecular weight product formation rate H is a value obtained by dividing the positive difference area (a) by the peak area (b) of the GPC before heating, and was obtained by the following formula.
Surface Roughness refers to a state where the surface of the optical film obtained by casting film formation is rough like a pine bark or dry rice paper.
the optical film is irradiated with light from a point light source at an angle of 45 degrees, an image projected on a plain screen is observed, and the surface roughness of a pine skin or dried rice paper is visually confirmed.
Table 6 summarizes the structure and evaluation results of the optical film.
the content of the residual unreacted monomer, the residual polymerization initiator, and the residual chain transfer agent is reduced, and the high molecular weight product formation rate H according to the present invention is within the scope of the present invention. It can be seen that the optical film produced using the composition does not cause surface roughness even when it is thinned, and at the same time, the gel-like foreign matters are greatly reduced.
the amount of crystallized matter remaining on the sieve is reduced by adjusting the solvent and its use conditions so that the value a according to the present invention is within the preferred range, and the alkali metal in the cellulose ester resin
the purified cellulose ester resins B4 to B6 having a reduced group 2 element content have a great effect in reducing gel-like foreign substances.
the thickness of the optical film is preferably in the range of 15 to 25 ⁇ m from the viewpoint of surface roughness.
the glossy film of the present invention is an optical film that does not cause surface roughness and has reduced gel-like foreign matter, and is suitable for polarizing plates, liquid crystal display devices, and other wide display devices.

Landscapes

Physics & Mathematics (AREA)
Chemical & Material Sciences (AREA)
General Physics & Mathematics (AREA)
Optics & Photonics (AREA)
Medicinal Chemistry (AREA)
Chemical Kinetics & Catalysis (AREA)
Health & Medical Sciences (AREA)
Polymers & Plastics (AREA)
Organic Chemistry (AREA)
Polarising Elements (AREA)
Manufacture Of Macromolecular Shaped Articles (AREA)
Processes Of Treating Macromolecular Substances (AREA)
Compositions Of Macromolecular Compounds (AREA)

PCT/JP2013/050971 2012-02-08 2013-01-18 Procédé pour la production de film optique Ceased WO2013118566A1 (fr)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
JP2012024600		2012-02-08
JP2012-024600		2012-02-08

Publications (1)

Publication Number	Publication Date
WO2013118566A1 true WO2013118566A1 (fr)	2013-08-15

Family

ID=48947335

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
PCT/JP2013/050971 Ceased WO2013118566A1 (fr)	2012-02-08	2013-01-18	Procédé pour la production de film optique

Country Status (2)

Country	Link
JP (1)	JPWO2013118566A1 (fr)
WO (1)	WO2013118566A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US20220017775A1 (en) *	2018-12-06	2022-01-20	Hoya Lens Thailand Ltd.	Optical member, curable composition, and production method for optical member

Citations (10)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
JPH11337731A (ja) *	1998-05-26	1999-12-10	Sekisui Chem Co Ltd	位相差板の製造方法及び位相差板製造装置
JP2008050581A (ja) *	2006-07-24	2008-03-06	Fujifilm Corp	セルロースアシレートフィルム、並びにそれを用いた偏光板及び液晶表示装置
JP2008095027A (ja) *	2006-10-13	2008-04-24	Fujifilm Corp	セルロースフィルム、光学補償シート、偏光板および液晶表示装置
WO2008062610A1 (fr) *	2006-11-25	2008-05-29	Konica Minolta Opto, Inc.	Procédé de fabrication de film optique, film d'ester de cellulose, polariseur et dispositif d'affichage à cristaux liquides
JP2008138015A (ja) *	2006-11-29	2008-06-19	Fujifilm Corp	セルロースアシレート組成物、セルロースアシレートフィルム、光学補償シート、偏光板および液晶表示装置
JP2009125975A (ja) *	2007-11-20	2009-06-11	Japan Steel Works Ltd:The	熱可塑性樹脂に含有された異物の除去方法
JP2009249574A (ja) *	2008-04-09	2009-10-29	Daicel Chem Ind Ltd	高置換度セルロース混合アシレートの製造方法
JP2009286930A (ja) *	2008-05-30	2009-12-10	Konica Minolta Opto Inc	光学フィルム、偏光板、及び液晶表示装置
JP2010122340A (ja) *	2008-11-18	2010-06-03	Konica Minolta Opto Inc	光学フィルム、その製造方法、それらを用いた偏光板、及び液晶表示装置
JP2011232428A (ja) *	2010-04-26	2011-11-17	Konica Minolta Opto Inc	傾斜位相差フィルムおよび液晶表示装置

2013
- 2013-01-18 JP JP2013557456A patent/JPWO2013118566A1/ja active Pending
- 2013-01-18 WO PCT/JP2013/050971 patent/WO2013118566A1/fr not_active Ceased

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
JPH11337731A (ja) *	1998-05-26	1999-12-10	Sekisui Chem Co Ltd	位相差板の製造方法及び位相差板製造装置
JP2008050581A (ja) *	2006-07-24	2008-03-06	Fujifilm Corp	セルロースアシレートフィルム、並びにそれを用いた偏光板及び液晶表示装置
JP2008095027A (ja) *	2006-10-13	2008-04-24	Fujifilm Corp	セルロースフィルム、光学補償シート、偏光板および液晶表示装置
WO2008062610A1 (fr) *	2006-11-25	2008-05-29	Konica Minolta Opto, Inc.	Procédé de fabrication de film optique, film d'ester de cellulose, polariseur et dispositif d'affichage à cristaux liquides
JP2008138015A (ja) *	2006-11-29	2008-06-19	Fujifilm Corp	セルロースアシレート組成物、セルロースアシレートフィルム、光学補償シート、偏光板および液晶表示装置
JP2009125975A (ja) *	2007-11-20	2009-06-11	Japan Steel Works Ltd:The	熱可塑性樹脂に含有された異物の除去方法
JP2009249574A (ja) *	2008-04-09	2009-10-29	Daicel Chem Ind Ltd	高置換度セルロース混合アシレートの製造方法
JP2009286930A (ja) *	2008-05-30	2009-12-10	Konica Minolta Opto Inc	光学フィルム、偏光板、及び液晶表示装置
JP2010122340A (ja) *	2008-11-18	2010-06-03	Konica Minolta Opto Inc	光学フィルム、その製造方法、それらを用いた偏光板、及び液晶表示装置
JP2011232428A (ja) *	2010-04-26	2011-11-17	Konica Minolta Opto Inc	傾斜位相差フィルムおよび液晶表示装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US20220017775A1 (en) *	2018-12-06	2022-01-20	Hoya Lens Thailand Ltd.	Optical member, curable composition, and production method for optical member

Also Published As

Publication number	Publication date
JPWO2013118566A1 (ja)	2015-05-11

Publication	Publication Date	Title
JP5200977B2 (ja)	2013-06-05	セルロースエステルフィルム、光学フィルム、偏光板、液晶表示装置およびセルロースエステルフィルムの溶融流延製膜方法
KR20090086079A (ko)	2009-08-10	광학 필름의 제조 방법, 셀룰로오스 에스테르 필름, 편광판 및 액정 표시 장치
KR20090063234A (ko)	2009-06-17	횡전계 스위칭 모드형 액정 표시 장치
WO2007102340A1 (fr)	2007-09-13	Film protecteur pour polariseur, plaque de polarisation et affichage a cristaux liquides aligne verticalement
KR20100105689A (ko)	2010-09-29	아크릴 수지 함유 필름, 그것을 사용한 편광판 및 액정 표시 장치
JP5262256B2 (ja)	2013-08-14	セルロースエステルフィルム、偏光板および液晶表示装置
JP6123677B2 (ja)	2017-05-10	光学フィルムとその製造方法、偏光板および液晶表示装置
WO2014136529A1 (fr)	2014-09-12	Film optique, plaque de polarisation contenant ce film optique, et dispositif d'affichage à cristaux liquides à alignement vertical
JP5304597B2 (ja)	2013-10-02	光学フィルム、偏光板及び液晶表示装置
JP2009251018A (ja)	2009-10-29	位相差フィルム、偏光板および液晶表示装置
KR20090077786A (ko)	2009-07-15	Ｉｐｓ형 액정 표시 장치 및 ｉｐｓ형 액정 표시 장치의 제조 방법
CN101874067B (zh)	2012-06-13	纤维素酯膜、纤维素酯膜的制造方法、偏振片以及液晶显示装置
JP5888040B2 (ja)	2016-03-16	偏光板保護フィルムおよびその製造方法、並びにそれを用いた偏光板および表示装置
JPWO2014068802A1 (ja)	2016-09-08	光学フィルムおよび光学フィルムの製造方法、偏光板および液晶表示装置
JP6024662B2 (ja)	2016-11-16	光学フィルムの製造方法
JP2009251094A (ja)	2009-10-29	位相差フィルム、偏光板および液晶表示装置
WO2013118566A1 (fr)	2013-08-15	Procédé pour la production de film optique
JP2010217846A (ja)	2010-09-30	セルロースエステルフィルム、偏光板、液晶表示装置およびセルロースエステルフィルムの溶融流延製膜方法
JP5594348B2 (ja)	2014-09-24	セルロースエステルフィルムの製造方法
JP2010032655A (ja)	2010-02-12	位相差フィルム、偏光板、液晶表示装置および位相差フィルムの製造方法
JPWO2011055603A1 (ja)	2013-03-28	光学フィルム、偏光板および液晶表示装置
KR101332882B1 (ko)	2013-11-25	편광판 및 그의 제조 방법
KR20090107496A (ko)	2009-10-13	광학 필름의 제조 방법, 광학 필름, 편광판 및 화상 표시 장치
JP5494331B2 (ja)	2014-05-14	溶融流延フィルム、偏光板及び液晶表示装置
JPWO2011111484A1 (ja)	2013-06-27	セルロースエステルの製造方法、セルロースエステル、及びセルロースエステルフィルム

Legal Events

Date	Code	Title	Description
2013-10-02	121	Ep: the epo has been informed by wipo that ep was designated in this application	Ref document number: 13746903 Country of ref document: EP Kind code of ref document: A1
2014-05-16	ENP	Entry into the national phase	Ref document number: 2013557456 Country of ref document: JP Kind code of ref document: A
2014-08-08	NENP	Non-entry into the national phase	Ref country code: DE
2015-03-04	122	Ep: pct application non-entry in european phase	Ref document number: 13746903 Country of ref document: EP Kind code of ref document: A1

WO2013118566A1 - Procédé pour la production de film optique - Google Patents

Info

Links

Images

Classifications

Definitions

Landscapes

Applications Claiming Priority (2)

Publications (1)

Family

ID=48947335

Family Applications (1)

Country Status (2)

Cited By (1)

Citations (10)

Patent Citations (10)

Cited By (1)

Also Published As

Similar Documents

Legal Events