JP2009035695A - Thermoplastic resin composition and film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition excellent in handleability and heat resistance, and exhibiting enhanced retardation performance. <P>SOLUTION: This thermoplastic resin composition consists essentially of an acrylic polymer having a glass transition temperature of 110°C or higher, and includes a fluorine-containing polymer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thermoplastic resin composition excellent in handleability, heat resistance and retardation performance, and a film containing the thermoplastic resin composition as a main component.

  In recent years, the demand for visibility (brighter, easier to see, better contrast, higher viewing angle, etc.) has become stricter as the screen size and usage environment of liquid crystal display devices expand. However, since only the improvement of the liquid crystal cell main body cannot sufficiently satisfy the demand for improving the visibility, it largely depends on the performance improvement of the optical film such as a retardation film.

  Therefore, the optical film such as a retardation film has high transparency, low photoelasticity, heat resistance, light resistance, high surface hardness, high mechanical strength, large retardation, and small wavelength dependence of retardation, Characteristics such as small dependence of the phase difference on the incident angle are required.

  Conventionally, stretch orientation of a film has been performed as a method of developing optical anisotropy of a transparent resin material. According to this stretch orientation, a film made of polymethyl methacrylate (PMMA) or polystyrene (PS) shows negative birefringence, and a film made of polycarbonate (PC) or cycloolefin resin (COP) has a positive birefringence. It is known to exhibit refractive properties. Here, positive birefringence means refractive index anisotropy that increases the refractive index in the same direction when the polymer molecular chain, which is a component of the film, is oriented by stretching. Is expressed. On the other hand, negative birefringence means that when a polymer molecular chain, which is a component constituting a film, is molecularly oriented by being stretched, the refractive index in the same direction is reduced, and at the same time, the refraction in the orthogonal direction is reduced. It means expressing the refractive index anisotropy that increases the rate.

  Currently, polycarbonate (PC) and cycloolefin resin (COP), such as norbornene amorphous polyolefin, which are excellent in terms of the magnitude of retardation, are mainly used as a resin for retardation film. Yes.

  However, since the PC retardation film has a high photoelastic coefficient and the retardation value (retardation value) changes greatly with a slight stress, a high tension cannot be applied at the time of bonding with another film. Further, when exposed to a high temperature in the state of being bonded, there is a problem that the retardation value is shifted or unevenness is likely to occur due to stress generated due to heat. Furthermore, there is a problem that the PC retardation film is inferior in weather resistance.

  The COP retardation film has a problem that it has high heat resistance but poor adhesion.

  On the other hand, acrylic resins typified by PMMA are known to have excellent optical transparency. However, since the retardation development performance is low, it is difficult to obtain the required retardation even when stretched. . Moreover, while the use environment of a liquid crystal display device becomes severe, it is difficult to give sufficient heat resistance to the stretched film of PMMA, when the request | requirement of the heat resistance of an optical film is increasing.

Recently, a film containing a lactone ring-containing polymer that has overcome the above problems and has excellent heat resistance and retardation has been reported (see, for example, Patent Documents 1 to 3).
Japanese Patent Laying-Open No. 2001-40228 (released on February 13, 2001) Japanese Patent Laying-Open No. 2005-281589 (released on October 13, 2005) JP 2006-171464 A (published June 29, 2006)

  However, in a film containing a lactone ring-containing polymer described in the above-mentioned patent document, if the content of the lactone ring is increased, the handleability of the polymer as a raw material of the film and the flexibility of the film are lowered, so that the phase difference The problem is that the improvement in performance is limited.

  The present invention has been made in view of the above-mentioned problems, and the object thereof is a thermoplastic resin composition having excellent handleability and heat resistance, and excellent retardation performance, and the thermoplastic resin composition. Is to realize a film including

  In order to solve the above problems, the thermoplastic resin composition according to the present invention contains an acrylic polymer having a glass transition temperature of 110 ° C. or higher and 200 ° C. or lower as a main component, and contains a fluorine-containing polymer. It is a feature.

  According to the said structure, a thermoplastic resin composition improves flexibility, maintaining the phase difference characteristic of an acrylic polymer. Therefore, according to the said structure, there exists an effect that the thermoplastic resin composition which is excellent in handling property and heat resistance, and has the outstanding phase difference performance can be provided.

  In the thermoplastic resin composition according to the present invention, the content of the acrylic polymer is in the range of 75 to 99% by mass, and the content of the fluorine-containing polymer is 1 to 25% by mass. It is preferable to be within the following range.

  According to the said structure, there exists the further effect that the thermoplastic resin composition which is more excellent in heat resistance and has the more excellent phase difference performance can be provided.

  In the thermoplastic resin composition according to the present invention, the fluorine-containing polymer is preferably a polymer having a structure derived from vinylidene fluoride as a main component.

  According to the said structure, there exists the further effect that the thermoplastic resin composition which is more excellent in handleability and has the more excellent phase difference performance can be provided.

  In the thermoplastic resin composition according to the present invention, it is preferable that the acrylic polymer contains a lactone ring structure.

  According to the said structure, there exists the further effect that the thermoplastic resin composition which is more excellent in heat resistance and has the more excellent phase difference performance can be provided.

  Furthermore, in the thermoplastic resin composition according to the present invention, the lactone ring structure has the following general formula (1).

(In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.)
It is preferable that it is a structure represented by these.

  In order to solve the above-mentioned problems, a film according to the present invention is characterized by including the thermoplastic resin composition according to the present invention.

  According to the said structure, since the thermoplastic resin composition which concerns on the said invention is included, there exists an effect that the film which is excellent in handleability and heat resistance can be provided.

  The film according to the present invention is preferably a retardation film.

  In addition, the film according to the present invention preferably has an in-plane retardation value of 20 nm to 500 nm at a wavelength of 589 nm per 100 μm thickness.

  If the in-plane retardation value at a wavelength of 589 nm per 100 μm thickness is smaller than 20 nm, the film becomes thick in order to obtain a desired retardation. On the other hand, when the thickness exceeds 500 nm, the phase difference changes due to a slight change in stretching conditions, and a film having a stable and uniform retardation characteristic tends to be difficult. Therefore, according to the above configuration, it is preferably used as a retardation film and an optical compensation film for LCDs (liquid crystal display devices) such as STN type LCDs, TN type LCDs, OCB type LCDs, VA type LCDs, and IPS type LCDs. it can.

  As described above, the thermoplastic resin composition according to the present invention contains an acrylic polymer having a glass transition temperature of 110 ° C. or higher and 200 ° C. or lower as a main component, and includes a fluorine-containing polymer. .

  For this reason, there exists an effect that the thermoplastic resin composition which is excellent in a handleability and heat resistance, and has the outstanding phase difference performance can be provided.

  Moreover, the film which concerns on this invention is characterized by including the thermoplastic resin composition which concerns on the said invention as mentioned above.

  For this reason, there exists an effect that the film which is excellent in handleability and heat resistance can be provided.

  The present invention will be described in detail below. In the present specification, “(meth) acrylic acid” means acrylic acid or methacrylic acid, “weight” is treated as a synonym for “mass”, and “weight%” is synonymous with “mass%”. deal with. In addition, “A to B” indicating a range indicates that it is A or more and B or less, and “ppm” means a value calculated in terms of mass unless otherwise specified. For example, 10,000 ppm represents 1% by mass. means.

  The “acrylic polymer” is a polymer obtained by polymerizing a monomer component containing a (meth) acrylic acid derivative such as (meth) acrylic acid or (meth) acrylic acid ester as a main component. In the present specification, the term “main component” means containing 50% by mass or more.

  The thermoplastic resin composition according to the present embodiment contains an acrylic polymer having a glass transition temperature of 110 ° C. or higher and 200 ° C. or lower as a main component, and includes a fluorine-containing polymer.

(I) Acrylic polymer The acrylic polymer is a resin obtained by polymerizing acrylic acid, methacrylic acid and derivatives thereof, and has a glass transition temperature in the range of 110 ° C. or higher and 200 ° C. or lower. If it is, it will not specifically limit, A well-known acrylic polymer can be used. For example, it can be produced by polymerizing a monomer composition containing (meth) acrylic acid ester as a main component.

  The glass transition temperature of the acrylic polymer is more preferably in the range of 120 ° C. or higher and 190 ° C. or lower, and still more preferably in the range of 130 ° C. or higher and 180 ° C. or lower.

  The weight average molecular weight of the acrylic polymer is preferably in the range of 10,000 to 2,000,000, from the viewpoint of improving mechanical strength, particularly flexibility when formed into a film, and is preferably 30,000 to 1, More preferably within the range of 000,000, still more preferably within the range of 50,000 to 500,000.

  Examples of the derivatives of acrylic acid and methacrylic acid include, for example, the general formula (2)

(Wherein R ⁴ and R ⁵ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms)
A compound (monomer) having a structure represented by: (meth) acrylic acid methyl, (meth) acrylic acid ethyl, (meth) acrylic acid n-propyl, (meth) acrylic acid n-butyl, (meth) acrylic acid Isobutyl, t-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate , 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate, and 2,3, (meth) acrylic acid 4,5-tetrahydroxypentyl and the like are preferable. These may be used alone or in combination of two or more. Among these, in particular, a compound having a structure represented by the general formula (2), methyl methacrylate, is more preferable from the viewpoint of excellent heat resistance and transparency.

  Examples of the compound represented by the general formula (2) include methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, isopropyl 2- (hydroxymethyl) acrylate, and 2- (hydroxymethyl). ) Normal butyl acrylate, tertiary butyl 2- (hydroxymethyl) acrylate, and the like. Among these, methyl 2- (hydroxymethyl) acrylate and 2- (hydroxymethyl) ethyl acrylate are preferable, and methyl 2- (hydroxymethyl) acrylate is particularly preferable in that the effect of improving heat resistance is high. As for the compound represented by General formula (2), only 1 type may be used and 2 or more types may be used together.

  The acrylic polymer may have a structure other than the structure obtained by polymerizing the (meth) acrylic acid ester described above. The structure other than the structure obtained by polymerizing (meth) acrylic acid ester is not particularly limited, but a hydroxyl group-containing monomer, an unsaturated carboxylic acid, the following general formula (3)

(Wherein R ⁶ represents a hydrogen atom or a methyl group, X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an —OAc group, a —CN group, a —CO—R ⁷ group, or a C— (O—R ⁸ group represents, Ac group represents an acetyl group, R ⁷ and R ⁸ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)
The polymer structural unit (repeating structural unit) constructed by polymerizing at least one selected from the monomers represented by

  The hydroxyl group-containing monomer is not particularly limited as long as it is a hydroxyl group-containing monomer other than the monomer represented by the general formula (2). For example, methallyl alcohol, allyl alcohol, 2-hydroxymethyl-1 -Allyl alcohol such as butene; α-hydroxymethyl styrene, α-hydroxyethyl styrene; 2- (hydroxyalkyl) acrylic acid ester such as methyl 2- (hydroxyethyl) acrylate; and the like. You may use, and may use 2 or more types together.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, α-substituted acrylic acid, α-substituted methacrylic acid and the like. These may be used alone or in combination of two or more. May be. Among these, acrylic acid and methacrylic acid are preferable in that the effects of the present invention are sufficiently exhibited.

  Examples of the compound represented by the general formula (3) include styrene, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, and vinyl acetate. These may be used alone. Two or more kinds may be used in combination. Among these, styrene and α-methylstyrene are particularly preferable in that the effects of the present invention are sufficiently exhibited.

  The acrylic polymer according to the present embodiment may be copolymerized with an N-substituted maleimide such as maleic anhydride, phenylmaleimide, cyclohexylmaleimide, or methylmaleimide from the viewpoint of improving heat resistance, and in the molecular chain ( A lactone ring structure, a glutaric anhydride structure, a glutarimide structure, or the like may be introduced into the main skeleton of the polymer or the main chain. Among these, a structure containing no nitrogen atom is preferable in that coloring (yellowing) of the film hardly occurs. In addition, it is preferable that the main chain has a lactone ring structure because the cyclization condensation reaction rate is high, crosslinking and the like hardly occur at high temperature molding, and the resin is less deteriorated.

  The polymer before the lactone cyclization reaction can be well copolymerized with a (meth) acrylic acid ester such as methyl methacrylate. In addition, the lactone ring structure in the main chain is represented by the general formula (1) to be described later in that the polymerization yield is high and a polymer having a high content of the lactone ring structure is easily obtained with a high polymerization yield. It is preferable that it is a structure.

  When the acrylic polymer is a polymer obtained by polymerizing a monomer containing a compound having a structure represented by the general formula (2), the acrylic polymer has a lactone ring structure. (Hereinafter, an acrylic polymer having a lactone ring structure is referred to as a “lactone ring-containing polymer”). Hereinafter, the lactone ring-containing polymer will be described.

  Examples of the lactone ring structure include the following general formula (1)

(In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.)
The structure represented by is mentioned.

  The organic residue in the general formulas (1), (2), and (3) is not particularly limited as long as it has a carbon number in the range of 1 to 20, but for example, a linear or branched alkyl group , A linear or branched alkylene group, an aryl group, an —OAc group, a —CN group and the like.

  The content of the lactone ring structure in the acrylic polymer is preferably in the range of 5 to 90% by mass, more preferably in the range of 10 to 85% by mass, and still more preferably in the range of 20 to 65% by mass. Especially preferably, it is in the range of 25 to 55% by mass. When the content of the lactone ring structure is less than 5% by mass, the heat resistance, solvent resistance, and surface hardness may be insufficient, and it may be difficult to obtain the necessary retardation when used as a film. Therefore, it is not preferable. When the content of the lactone ring structure is more than 90% by mass, the moldability tends to be poor, which is not preferable.

  In the lactone ring-containing polymer, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is that of a polymer structural unit (repeating structural unit) constructed by polymerizing (meth) acrylic acid ester. In this case, it is preferably in the range of 10 to 95% by mass, more preferably in the range of 10 to 90% by mass, further preferably in the range of 40 to 90% by mass, and particularly preferably in the range of 50 to 90% by mass. .

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing a hydroxyl group-containing monomer, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is preferably 0 to It is in the range of 30% by mass, more preferably in the range of 0 to 20% by mass, still more preferably in the range of 0 to 15% by mass, and particularly preferably in the range of 0 to 10% by mass.

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing an unsaturated carboxylic acid, the content ratio of the structure other than the lactone ring structure represented by the general formula (1) is preferably 0 to 30. It is in the range of mass%, more preferably in the range of 0 to 20 mass%, further preferably in the range of 0 to 15 mass%, particularly preferably in the range of 0 to 10 mass%.

  In the case of a polymer structural unit (repeating structural unit) constructed by polymerizing the monomer represented by the general formula (3), it contains a structure other than the lactone ring structure represented by the general formula (1). The ratio is preferably in the range of 0 to 30% by mass, more preferably in the range of 0 to 20% by mass, still more preferably in the range of 0 to 15% by mass, and particularly preferably in the range of 0 to 10% by mass. is there.

  The method for producing the lactone ring-containing polymer is not particularly limited, but preferably, after the polymer having a hydroxyl group and an ester group in the molecular chain is obtained by the polymerization step, the obtained polymer is heat-treated. Thus, a lactone ring-containing polymer can be obtained by carrying out a lactone cyclization condensation step for introducing a lactone ring structure into the polymer.

  A polymer having a hydroxyl group and an ester group in the molecular chain can be obtained by conducting a polymerization reaction of the monomer composition containing the compound represented by the general formula (2).

  The content ratio of the compound represented by the general formula (2) in the monomer composition provided in the polymerization reaction (polymerization step) is preferably within the range of 5 to 90% by mass, more preferably 10 to 50% by mass. Is more preferably in the range of 15 to 40% by mass, and particularly preferably in the range of 20 to 35% by mass. When the content ratio of the monomer represented by the general formula (2) in the monomer component provided in the polymerization step is less than 5% by mass, heat resistance, solvent resistance, and surface hardness may be insufficient. Yes, not preferred. If the content ratio of the monomer represented by the general formula (2) in the monomer composition provided in the polymerization step is more than 90% by mass, gelation may occur during polymerization or lactone cyclization, The molding processability of the obtained polymer may be poor, which is not preferable.

  The monomer composition used in the polymerization step may contain a monomer other than the monomer represented by the general formula (2). As such a monomer, for example, the (meth) acrylic acid ester, the hydroxyl group-containing monomer, the unsaturated carboxylic acid, and the monomer represented by the general formula (3) are preferably exemplified. Only one type of monomer other than the monomer represented by formula (2) may be used, or two or more types may be used in combination.

  When (meth) acrylic acid esters other than the monomer represented by the general formula (2) are used, the content ratio in the monomer component to be subjected to the polymerization step is sufficient to exert the effect of the present invention. , Preferably in the range of 10 to 95% by weight, more preferably in the range of 40 to 90% by weight, still more preferably in the range of 50 to 90% by weight, particularly preferably in the range of 60 to 85% by weight, most preferably Is in the range of 65-80 mass%.

  In the case of using a hydroxyl group-containing monomer other than the monomer represented by the general formula (2), the content ratio in the monomer component to be subjected to the polymerization step is sufficient to exert the effect of the present invention. Preferably it is in the range of 0 to 30% by mass, more preferably in the range of 0 to 20% by mass, still more preferably in the range of 0 to 15% by mass, and particularly preferably in the range of 0 to 10% by mass.

  When using an unsaturated carboxylic acid, the content ratio in the monomer component to be subjected to the polymerization step is preferably in the range of 0 to 30% by mass, more preferably 0, in order to sufficiently exhibit the effects of the present invention. It is in the range of -20% by mass, more preferably in the range of 0-15% by mass, particularly preferably in the range of 0-10% by mass.

  When the monomer represented by the general formula (3) is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by mass in order to sufficiently exhibit the effects of the present invention. More preferably, it is in the range of 0 to 20% by mass, more preferably in the range of 0 to 15% by mass, and particularly preferably in the range of 0 to 10% by mass.

  The form of the polymerization reaction for polymerizing the monomer composition to obtain a polymer having a hydroxyl group and an ester group in the molecular chain is preferably a polymerization form using a solvent, and solution polymerization is particularly preferred. .

  The polymerization temperature and the polymerization time vary depending on the type of monomer (monomer composition) used, the ratio of use, etc., but preferably the polymerization temperature is in the range of 0 to 150 ° C., and the polymerization time is 0.5 to The polymerization time is in the range of 20 hours, more preferably, the polymerization temperature is in the range of 80 to 140 ° C., and the polymerization time is in the range of 1 to 10 hours.

  In the case of a polymerization form using a solvent, the polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran Etc., and only one of these may be used, or two or more may be used in combination. Moreover, since the residual volatile matter of the lactone ring containing polymer finally obtained will increase when the boiling point of the solvent to be used is too high, the thing whose boiling point is in the range of 50-200 degreeC is preferable.

  During the polymerization reaction, a polymerization initiator may be added as necessary. Although it does not specifically limit as a polymerization initiator, For example, t-amyl peroxy isononanoate, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t- Organic peroxides such as butylperoxyisopropyl carbonate and t-amylperoxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexanecarbonitrile), Azo compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile); and the like. These may be used alone or in combination of two or more. What is necessary is just to set the usage-amount of a polymerization initiator suitably according to the combination of the monomer to be used, reaction conditions, etc., and it does not specifically limit.

  When carrying out the polymerization, it is preferable to control the concentration of the produced polymer in the polymerization reaction mixture to be 70% by mass or less in order to suppress gelation of the reaction solution. Specifically, when the concentration of the produced polymer in the polymerization reaction mixture exceeds 70% by mass, it is preferable that the polymerization solvent is appropriately added to the polymerization reaction mixture so as to be controlled to 70% by mass or less. . The concentration of the produced polymer in the polymerization reaction mixture is more preferably 60% by mass or less, and still more preferably 50% by mass or less. In addition, since productivity will fall when the density | concentration of the polymer in a polymerization reaction mixture is too low, it is preferable that the density | concentration of the polymer in a polymerization reaction mixture is 10 mass% or more, and it is 20 mass% or more. Is more preferable.

  The form in which the polymerization solvent is appropriately added to the polymerization reaction mixture is not particularly limited, and the polymerization solvent may be added continuously or intermittently. By controlling the concentration of the produced polymer in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more sufficiently suppressed, and in particular, to increase the lactone ring content and improve the heat resistance. Even when the ratio of hydroxyl groups and ester groups in the molecular chain is increased, gelation can be sufficiently suppressed. The polymerization solvent to be added may be the same type of solvent used during the initial charging of the polymerization reaction or may be a different type of solvent, but is the same as the solvent used during the initial charging of the polymerization reaction. It is preferable to use different types of solvents. Further, the polymerization solvent to be added may be only one type of solvent or a mixed solvent of two or more types.

  The polymer obtained in the above polymerization step is an ester group in the molecular chain (in the case where the polymer is a monomer containing a compound having a structure represented by the general formula (2), Hydroxyl group and ester group), and the weight average molecular weight of the polymer is preferably in the range of 10,000 to 2,000,000, more preferably in the range of 30,000 to 1,000,000. Preferably, the range of 50,000-500,000 is more preferable.

  In the polymer obtained by polymerizing the monomer containing the compound having the structure represented by the general formula (2), the lactone ring structure is introduced into the polymer by heat treatment in the subsequent lactone cyclization condensation step. It can be made into a lactone ring-containing polymer.

  In the polymerization reaction mixture obtained when the above polymerization step is completed, a solvent is usually contained in addition to the obtained polymer. When the above polymer is a lactone ring-containing polymer, it is not necessary to completely remove the solvent and take out the polymer in a solid state, and the subsequent lactone cyclization condensation step is performed in a state containing the solvent. Is preferred. If necessary, after taking out in a solid state, a solvent suitable for the subsequent lactone cyclization condensation step may be added again.

  The reaction for introducing a lactone ring structure into the polymer is a reaction in which a hydroxyl group and an ester group present in the molecular chain of the polymer are cyclized and condensed to form a lactone ring structure by heating. Alcohol is produced as a by-product by condensation. By forming the lactone ring structure in the molecular chain of the polymer (in the main skeleton of the polymer), high heat resistance is imparted to the polymer. If the reaction rate of the cyclization condensation reaction leading to the lactone ring structure is insufficient, the heat resistance will not be improved sufficiently, or the condensation reaction will occur during the molding process due to the heat treatment during molding, and the resulting alcohol will be contained in the molded product. It is not preferable because it may exist as bubbles or silver streaks.

  The lactone ring-containing polymer obtained in the lactone cyclization condensation step preferably has a lactone ring structure represented by the general formula (1).

  The method for heat-treating the polymer is not particularly limited, and a known method can be used. For example, you may heat-process the polymerization reaction mixture containing the solvent obtained by the superposition | polymerization process as it is. Moreover, you may heat-process using a ring-closing catalyst as needed in presence of a solvent. Further, the heat treatment can be performed using a heating furnace or reaction apparatus having a vacuum apparatus or a devolatilizing apparatus for removing volatile components, an extruder having a devolatilizing apparatus, or the like.

  In carrying out the cyclization condensation reaction, other thermoplastic resins may coexist in addition to the polymer. Further, when performing the cyclization condensation reaction, if necessary, an esterification catalyst or a transesterification catalyst such as p-toluenesulfonic acid generally used as a catalyst for the cyclization condensation reaction may be used. Organic carboxylic acids such as propionic acid, benzoic acid, acrylic acid, and methacrylic acid may be used as a catalyst. As disclosed in JP-A-61-254608 and JP-A-61-261303, basic compounds, organic carboxylates, carbonates and the like may be used.

  In carrying out the cyclization condensation reaction, it is preferable to use an organic phosphorus compound as a catalyst. By using an organophosphorus compound as a catalyst, the cyclization condensation reaction rate can be improved, and coloring of the resulting lactone ring-containing polymer can be greatly reduced. Furthermore, by using an organophosphorus compound as a catalyst, it is possible to suppress a decrease in molecular weight that can occur when a devolatilization step described later is used in combination, and to impart excellent mechanical strength.

  Examples of the organic phosphorus compound that can be used as a catalyst in the cyclocondensation reaction include alkyl (aryl) phosphonous acids such as methylphosphonous acid, ethylphosphonous acid, and phenylphosphonous acid (however, Tautomers (which may be alkyl (aryl) phosphinic acid) and diesters or monoesters thereof; dimethylphosphinic acid, diethylphosphinic acid, diphenylphosphinic acid, phenylmethylphosphinic acid, phenylethylphosphinic acid, etc. Dialkyl (aryl) phosphinic acids and esters thereof; alkyl (aryl) phosphonic acids such as methyl phosphonic acid, ethyl phosphonic acid, trifluoromethyl phosphonic acid, phenyl phosphonic acid, and their diesters or monoesters; methyl phosphine Alkyl (aryl) phosphinic acids such as ethylphosphinic acid and phenylphosphinic acid and their esters; methyl phosphite, ethyl phosphite, phenyl phosphite, dimethyl phosphite, diethyl phosphite, Phosphorous acid diester or monoester or triester such as diphenyl phosphate, trimethyl phosphite, triethyl phosphite, triphenyl phosphite; methyl phosphate, ethyl phosphate, 2-ethylhexyl phosphate, isodecyl phosphate, Lauryl phosphate, stearyl phosphate, isostearyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, di-2-ethylhexyl phosphate, diisodecyl phosphate, dilauryl phosphate, distearyl phosphate, diisophosphate Stearyl, diphenyl phosphate, trimethyl phosphate, phosphorus Phosphoric diesters or monoesters or triesters such as triethyl, triisodecyl phosphate, trilauryl phosphate, tristearyl phosphate, triisostearyl phosphate, triphenyl phosphate; methylphosphine, ethylphosphine, phenylphosphine, dimethylphosphine, diethyl Mono-, di- or trialkyl (aryl) phosphine such as phosphine, diphenylphosphine, trimethylphosphine, triethylphosphine, triphenylphosphine; methyldichlorophosphine, ethyldichlorophosphine, phenyldichlorophosphine, dimethylchlorophosphine, diethylchlorophosphine, diphenylchlorophosphine Alkyl (aryl) halogen phosphines such as methyl phosphine oxide, ethyl phosphine oxide , Phenylphosphine oxide, dimethylphosphine oxide, diethylphosphine oxide, diphenylphosphine oxide, trimethylphosphine oxide, triethylphosphine oxide, triphenylphosphine oxide, mono-, di- or trialkyl (aryl) phosphines; tetramethylphosphonium chloride, tetraethyl chloride Halogenated tetraalkyl (aryl) phosphonium such as phosphonium and tetraphenylphosphonium chloride; and the like. Among these, alkyl (aryl) phosphonous acid, phosphorous acid diester or monoester, phosphoric acid diester or monoester, and alkyl (aryl) phosphonic acid are preferable because of high catalytic activity and low colorability. ) Phosphorous acid, phosphorous acid diester or monoester, phosphoric acid diester or monoester are more preferred, and alkyl (aryl) phosphonous acid, phosphoric acid diester or monoester is particularly preferred. These organic phosphorus compounds may use only 1 type and may use 2 or more types together.

  The amount of the catalyst used in the cyclization condensation reaction is not particularly limited, but is preferably in the range of 0.001 to 5% by mass, more preferably 0.01 to 2.5% by mass with respect to the polymer. %, More preferably in the range of 0.01 to 1% by weight, particularly preferably in the range of 0.05 to 0.5% by weight. When the amount of the catalyst used is less than 0.001% by mass, the reaction rate of the cyclization condensation reaction may not be sufficiently improved. On the other hand, when the amount exceeds 5% by mass, coloring may occur, This is not preferable because it may be difficult to melt and form by crosslinking of the coalesced.

  The addition timing of the catalyst is not particularly limited, and it may be added at the beginning of the reaction, during the reaction, or both.

  It is preferable to carry out the cyclization condensation reaction in the presence of a solvent and to use a devolatilization step in combination with the cyclization condensation reaction. In this case, a mode in which the devolatilization step is used throughout the cyclization condensation reaction and a mode in which the devolatilization step is not used throughout the entire cyclization condensation reaction and are used only in a part of the process. In the method using the devolatilization step in combination, the alcohol produced as a by-product in the condensation cyclization reaction is forcibly devolatilized and removed, so that the equilibrium of the reaction is advantageous for the production side.

  The devolatilization step refers to a step of removing a volatile component such as a solvent and a residual monomer and an alcohol by-produced by a cyclization condensation reaction leading to a lactone ring structure, if necessary under reduced pressure heating conditions. If this removal treatment is insufficient, the residual volatile components in the produced resin increase, resulting in problems such as coloration due to alteration during molding, and molding defects such as bubbles and silver streaks.

  In the case of a form in which a devolatilization step is used throughout the cyclization condensation reaction, the apparatus to be used is not particularly limited, but a devolatilization apparatus comprising a heat exchanger and a devolatilization tank in order to perform the present invention more effectively. It is preferable to use an extruder with a vent, or a devolatilizer and an extruder arranged in series, and use a devolatilizer or vented extruder comprising a heat exchanger and a devolatilizer. Is more preferable.

  The reaction treatment temperature in the case of using a devolatilizer comprising the heat exchanger and the devolatilizer is preferably in the range of 150 to 350 ° C, more preferably in the range of 200 to 300 ° C. If the reaction treatment temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient and the residual volatile matter may increase, and if it is higher than 350 ° C., coloring or decomposition may occur.

  When using the devolatilizer comprising the heat exchanger and the devolatilizer, the pressure during the reaction treatment is preferably within the range of 931 to 1.33 hPa (700 to 1 mmHg), and 798 to 66.5 hPa (600 to More preferably within the range of 50 mmHg). When the said pressure is higher than 931 hPa, there exists a problem that the volatile matter including alcohol will remain easily, and when it is lower than 1.33 hPa, there exists a problem that industrial implementation will become difficult.

  When using the extruder with a vent, one or a plurality of vents may be used, but it is preferable to have a plurality of vents.

  In the case of using the vented extruder, the reaction treatment temperature is preferably in the range of 150 to 350 ° C, more preferably in the range of 200 to 300 ° C. If the temperature is lower than 150 ° C., the cyclization condensation reaction may be insufficient and the residual volatile content may increase. If the temperature is higher than 350 ° C., coloring or decomposition may occur.

  In the case of using the extruder with a vent, the pressure during the reaction treatment is preferably within a range of 931 to 1.33 hPa (700 to 1 mmHg), and more preferably within a range of 798 to 13.3 hPa (600 to 10 mmHg). When the pressure is higher than 931 hPa, there is a problem that volatile components including alcohol easily remain, and when the pressure is lower than 1.33 hPa, there is a problem that industrial implementation becomes difficult.

  In addition, in the case of using the devolatilization step throughout the cyclization condensation reaction, as described later, the physical properties of the lactone ring-containing polymer obtained may be deteriorated under severe heat treatment conditions. It is preferable to use a catalyst for a dealcoholization reaction and under a mild condition as much as possible using an extruder with a vent.

  In the case of using a devolatilization step throughout the cyclization condensation reaction, preferably, the polymer obtained in the polymerization step is introduced into the cyclization condensation reactor system together with a solvent. Then, it may be passed once again through the reactor system such as an extruder with a vent.

  You may perform the form used together only in a part of process, without using a devolatilization process over the whole process of cyclization condensation reaction. For example, the apparatus for producing the polymer is further heated, and if necessary, a part of the devolatilization step is used together to advance the cyclization condensation reaction to some extent in advance, and then the devolatilization step is used at the same time. In this mode, the cyclization condensation reaction is performed to complete the reaction.

  In the embodiment in which the devolatilization step is used throughout the cyclization condensation reaction described above, for example, when the polymer is heat-treated at a high temperature of about 250 ° C. or higher using a twin screw extruder, Depending on the difference, partial decomposition or the like may occur before the cyclization condensation reaction occurs, and the physical properties of the resulting lactone ring-containing polymer may be deteriorated. Therefore, if the cyclization condensation reaction is allowed to proceed to some extent before the cyclization condensation reaction using the devolatilization step at the same time, the latter reaction conditions can be relaxed and the physical properties of the resulting lactone ring-containing polymer deteriorated. Is preferable. A particularly preferred form is a form in which the devolatilization step is started after a while from the start of the cyclization condensation reaction, that is, the hydroxyl group and ester group present in the molecular chain of the polymer obtained in the polymerization step are cyclized in advance. A form in which a condensation reaction is performed to increase the cyclization condensation reaction rate to some extent, and then a cyclization condensation reaction using a devolatilization step in combination is performed. Specifically, for example, a cyclization condensation reaction is allowed to proceed to a certain reaction rate in the presence of a solvent in advance using a kettle-type reactor, and then a reactor equipped with a devolatilizer, for example, a heat Preferred is a mode in which the cyclization condensation reaction is completed with a devolatilizer comprising an exchanger and a devolatilization tank, an extruder with a vent, or the like. Particularly in this form, it is more preferable that a catalyst for the cyclization condensation reaction is present.

  As described above, the hydroxyl group and ester group present in the molecular chain of the polymer obtained in the polymerization step are subjected to a cyclization condensation reaction in advance to increase the cyclization condensation reaction rate to some extent. The method of carrying out the cyclization condensation reaction simultaneously used is a preferred form for obtaining a lactone ring-containing polymer. With this configuration, a lactone ring-containing polymer having a higher cyclization condensation reaction rate, a higher glass transition temperature, and excellent heat resistance can be obtained. In this case, as a measure of the cyclization condensation reaction rate, the weight loss rate between 150 and 300 ° C. in the dynamic TG measurement shown in the examples is preferably 2% or less, more preferably 1.5% or less. More preferably, it is 1% or less.

  The reactor that can be employed in the cyclization condensation reaction that is performed in advance before the cyclization condensation reaction using the devolatilization process at the same time is not particularly limited, but preferably an autoclave, a kettle reactor, a heat exchanger, and a devolatilization tank A vented extruder suitable for a cyclocondensation reaction using a devolatilization step at the same time can also be used. More preferred are autoclaves and kettle reactors. However, even when using a reactor such as an extruder with a vent, by adjusting the temperature condition, barrel condition, screw shape, screw operating condition, etc. It is possible to carry out the cyclization condensation reaction in the same state as the reaction state in the kettle reactor.

  In the case of the cyclization condensation reaction performed in advance before the cyclization condensation reaction using the devolatilization step at the same time, preferably, a mixture containing the polymer and the solvent obtained in the polymerization step is added (i) a catalyst. And (ii) a method of performing a heat reaction without a catalyst, and a method of performing the above (i) or (ii) under pressure.

  The “mixture containing a polymer and a solvent” to be introduced into the cyclization condensation reaction in the lactone cyclization condensation step may be the polymerization reaction mixture obtained in the polymerization step as it is, or once the solvent is removed. After that, it means that a solvent suitable for the cyclization condensation reaction may be added again.

  The solvent that can be re-added in the cyclization condensation reaction that is carried out in advance before the cyclization condensation reaction simultaneously used in the devolatilization step is not particularly limited, for example, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; chloroform, DMSO, tetrahydrofuran and the like may be used, but the same solvent as that used in the polymerization step is preferable.

  Examples of the catalyst to be added in the above method (i) include commonly used esterification catalysts such as p-toluenesulfonic acid or transesterification catalysts, basic compounds, organic carboxylates, and carbonates. In the form, it is preferable to use the organophosphorus compound described above.

  The addition timing of the catalyst is not particularly limited, and it may be added at the beginning of the reaction, during the reaction, or both. The amount of the catalyst to be added is not particularly limited, but is preferably in the range of 0.001 to 5 mass%, more preferably in the range of 0.01 to 2.5 mass%, still more preferably based on the weight of the polymer. It is in the range of 0.01 to 0.1% by mass, particularly preferably in the range of 0.05 to 0.5% by mass. The heating temperature and heating time in method (i) are not particularly limited, but the heating temperature is preferably room temperature or higher, more preferably 50 ° C. or higher, and the heating time is preferably in the range of 1 to 20 hours. More preferably, it is in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. Further, if the heating time is too long, the resin may be colored or decomposed, which is not preferable.

  Examples of the method (ii) include a method of heating the polymerization reaction mixture obtained in the polymerization step as it is using a pressure-resistant kettle or the like. The heating temperature is preferably 100 ° C. or higher, more preferably 150 ° C. or higher. The heating time is preferably in the range of 1 to 20 hours, more preferably in the range of 2 to 10 hours. If the heating temperature is low or the heating time is short, the cyclization condensation reaction rate is lowered, which is not preferable. Further, if the heating time is too long, the resin may be colored or decomposed, which is not preferable.

  Both the above methods (i) and (ii) have no problem even under pressure depending on conditions. Moreover, in the case of the cyclization condensation reaction performed beforehand before the cyclization condensation reaction which used the devolatilization process simultaneously, even if a part of the solvent volatilizes naturally during the reaction, there is no problem.

  The weight loss rate between 150 and 300 ° C. in the dynamic TG measurement at the end of the cyclization condensation reaction performed in advance before the cyclization condensation reaction simultaneously using the devolatilization process, that is, immediately before the start of the devolatilization process, It is preferably 2% or less, more preferably 1.5% or less, and still more preferably 1% or less. When the weight reduction rate is higher than 2%, the cyclization condensation reaction rate does not rise to a sufficiently high level even if the cyclization condensation reaction is performed simultaneously with the devolatilization step, and the physical properties of the resulting lactone ring-containing polymer. May decrease. In addition, when performing said cyclization condensation reaction, in addition to a polymer, you may coexist other thermoplastic resins.

  Cyclization using a hydroxyl group and an ester group present in the molecular chain of the polymer obtained in the polymerization step in advance by a cyclization condensation reaction to increase the cyclization condensation reaction rate to a certain extent, followed by a devolatilization step at the same time. In the case of a form in which a condensation reaction is performed, a polymer obtained by a previously performed cyclization condensation reaction (a polymer in which at least a part of hydroxyl groups and ester groups in the molecular chain are subjected to a cyclization condensation reaction) and a solvent are isolated. Without carrying out, you may perform the cyclization condensation reaction which used the devolatilization process simultaneously. In addition, if necessary, other treatments such as re-adding a solvent after isolating the above polymer (a polymer in which at least a part of the hydroxyl group and ester group present in the molecular chain have undergone cyclization condensation reaction) are performed. After that, you may perform the cyclization condensation reaction which used the devolatilization process simultaneously.

  The devolatilization step is not limited to being completed at the same time as the cyclization condensation reaction, and may be completed after a lapse of time from the completion of the cyclization condensation reaction.

  In addition, even after the catalyst is added and the cyclization reaction is sufficiently performed, a small amount of unreacted reactive groups remain in the polymer. Problems such as increase and thickening due to cross-linking between polymer molecules may occur. For this reason, after adding a catalyst and fully performing a cyclization condensation reaction, it is preferable to add the deactivation agent of a cyclization condensation catalyst.

  In the cyclization condensation reaction, an acidic catalyst or a basic catalyst is often used. In that case, the deactivator deactivates the catalyst by a neutralization reaction. For this reason, when the catalyst is an acidic substance, the deactivating agent may be a basic substance. Conversely, when the catalyst is a basic substance, the deactivating agent may be an acidic substance.

  The deactivator is not particularly limited as long as it does not generate a substance or the like that inhibits the physical properties of the resin composition during heat processing. When a basic substance is used as the deactivator, for example, a metal carboxylate, a metal complex, A metal oxide etc. are mentioned. Among these, metal carboxylates and metal oxides are preferable, and metal carboxylates are particularly preferable.

  The metal in the basic substance is not particularly limited as long as it does not inhibit the physical properties of the resin composition and causes environmental pollution at the time of disposal. For example, alkali metals such as lithium, sodium and potassium; magnesium and calcium Alkaline earth metals such as strontium and barium; zinc; zirconium and the like.

  The carboxylic acid constituting the metal carboxylate is not particularly limited. For example, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, Examples include myristic acid, palmitic acid, stearic acid, behenic acid, tridecanoic acid, pentadecanoic acid, heptadecanoic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, and adipic acid. .

  Although it does not specifically limit as an organic component in the said metal complex, Acetyl acetone etc. are mentioned. Examples of the metal oxide include zinc oxide, calcium oxide, magnesium oxide and the like, and zinc oxide is preferable.

  Moreover, when using an acidic substance for a quencher, an organic phosphoric acid compound, carboxylic acid, etc. are mentioned, for example. The quenching agent that can be used in the present embodiment may be used alone or in combination of two or more. The quenching agent may be used in any form such as a solid state such as a powder or a state dispersed in a solvent such as a suspension or an aqueous solution.

  The addition amount of the deactivator may be appropriately adjusted according to the amount of the catalyst used in the cyclization condensation reaction, and is not particularly limited, but is preferably in the range of 10 to 10,000 ppm with respect to the acrylic polymer. Of these, a range of 50 to 5,000 ppm is more preferable, and a range of 100 to 3,000 ppm is still more preferable.

  When the addition amount of the deactivator is less than 10 ppm, the function of the deactivator becomes insufficient, and thickening due to foaming or cross-linking between polymer molecules may occur during molding. On the other hand, when the addition amount of the deactivator exceeds 10,000 ppm, the deactivator is used more than necessary, and the physical properties of the resin composition may be inhibited, for example, the molecular weight is lowered.

  The timing of adding the deactivator is after the catalyst is added and the cyclization condensation reaction is sufficiently performed in the production of the acrylic polymer, and before the obtained resin composition is thermally processed. There is no particular limitation. For example, a deactivator is added at a predetermined stage during production of an acrylic polymer, or after producing an acrylic polymer, the acrylic polymer, the deactivator, and other components are simultaneously heated and melted. A method of kneading by mixing; a method in which an acrylic polymer and other components are heated and melted, and then adding a deactivator; and a method in which the acrylic polymer is heated and melted and then deactivating, and other The method etc. which add and knead | mix a component etc. are mentioned.

  Moreover, when adding a quencher, it is preferable to perform a devolatilization process after kneading with a quencher from a viewpoint that the obtained acrylic polymer hardly causes foaming at the time of heat processing. As the devolatilization step, the same step as the devolatilization step performed in the production of the lactone ring-containing polymer described above can be performed.

  The obtained lactone ring-containing polymer preferably has a weight reduction rate of 150% to 300 ° C. in dynamic TG measurement of 1% or less, more preferably 0.5% or less, and still more preferably 0.3%. % Or less.

  Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, it is possible to avoid the disadvantage that bubbles and silver streaks enter the molded product after molding. Furthermore, since the lactone ring structure is sufficiently introduced into the polymer due to a high cyclization condensation reaction rate, the obtained lactone ring-containing polymer has sufficiently high heat resistance.

  The lactone ring-containing polymer preferably has a coloring degree (YI) in a 15% by mass chloroform solution of 6 or less, more preferably 3 or less, still more preferably 2 or less, and most preferably 1 or less. If the coloring degree (YI) exceeds 6, transparency may be impaired due to coloring, and it may not be used for the intended purpose.

  The lactone ring-containing polymer preferably has a 5% weight loss temperature in thermogravimetric analysis (TG) of 330 ° C. or higher, more preferably 350 ° C. or higher, and still more preferably 360 ° C. or higher. The 5% weight loss temperature in thermogravimetric analysis (TG) is an indicator of thermal stability, and if it is less than 330 ° C., sufficient thermal stability may not be exhibited.

  The total amount of residual volatile components contained in the lactone ring-containing polymer is preferably 1,500 ppm or less, more preferably 1,000 ppm or less. When the total amount of residual volatile components is more than 1,500 ppm, it causes molding defects such as coloring due to alteration during molding, foaming, silver streak and the like.

  The lactone ring-containing polymer has a total light transmittance of 85% or more, more preferably 88% or more, still more preferably, of a molded product obtained by injection molding, as measured by a method according to ASTM-D-1003. Is 90% or more. The total light transmittance is a measure of transparency, and if it is less than 85%, the transparency is lowered and there is a possibility that it cannot be used for the intended purpose.

(II) Fluorine-containing polymer The fluorine-containing polymer is not particularly limited as long as it is a polymer containing a fluorine atom, and a conventionally known fluorine-containing polymer can be used. As the fluorine-containing polymer, for example, a monomer component containing one or more of vinylidene fluoride, trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, perfluoroalkyl vinyl ether, etc. The polymer obtained is mentioned.

  Among these, from the viewpoint of transparency of the obtained thermoplastic resin composition, at least selected from the group consisting of trifluoroethylene, tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, perfluoroalkyl vinyl ether and ethylene. A polymer obtained by copolymerizing one kind of monomer and vinylidene fluoride and a polymer obtained by polymerizing vinylidene fluoride alone (polyvinylidene fluoride) are more preferable.

  In the case where the fluorine-containing polymer contains polyvinylidene fluoride, the ratio of polyvinylidene fluoride in the fluorine-containing polymer is preferably in the range of 20% by mass to 100% by mass, and 50% by mass to More preferably, it is in the range of 100% by mass.

  Of course, the polymer containing fluorine atoms may be further copolymerized with a monomer that does not contain fluorine. In this case, the flexibility or position of the resulting thermoplastic resin composition is not limited. There is a possibility of adversely affecting the phase difference performance. For this reason, the ratio of the structure derived from the monomer not containing fluorine in the fluorine-containing polymer is more preferably in the range of 0 to 80% by mass, further preferably in the range of 0 to 50% by mass, and 0% by mass. Most preferably.

  In the present specification, “monomer-derived structure” means a structure formed when a monomer is polymerized. For example, “vinylidene fluoride-derived structure” means vinylidene fluoride. It means the structure formed when polymerized.

  The weight average molecular weight of the fluorine-containing polymer is preferably in the range of 50,000 to 700,000, and more preferably in the range of 100,000 to 600,000. If the weight average molecular weight of the fluorine-containing polymer is less than 100,000, the flexibility of the resulting thermoplastic resin composition tends to decrease. If it exceeds 700,000, the resulting thermoplastic resin composition may be molded. It tends to be difficult.

(III) Thermoplastic Resin Composition The thermoplastic resin composition according to the present embodiment includes the above-described acrylic polymer and the above-described fluorine-containing polymer.

  The content of the acrylic polymer in the thermoplastic resin composition is 50% by mass or more, and in the range of 75% by mass to 99% by mass from the viewpoint of glass transition temperature and transparency of the obtained thermoplastic resin composition. It is more preferable that the content is within the range of 80% by mass to 99% by mass, and particularly preferably within the range of 85% by mass to 95% by mass. When content of the said acrylic polymer is less than 50 mass%, there exists a tendency for the optical characteristic at the time of setting it as heat resistance and a film to fall.

  The content of the fluorine-containing polymer in the thermoplastic resin composition is in the range of 1% by mass to 25% by mass from the viewpoint of not inhibiting the glass transition temperature and transparency of the obtained thermoplastic resin composition. Preferably, it is in the range of 1% by mass to 20% by mass, more preferably in the range of 5% by mass to 15% by mass.

  In addition, the positive / negative of the birefringence of a thermoplastic resin composition can be adjusted to arbitrary values according to a use. For example, in the case of using a positive birefringent fluorine-containing polymer such as polyvinylidene fluoride, a positive birefringent acrylic polymer can be used in order to further develop the phase difference. In addition, when using a positively birefringent fluorine-containing polymer and wishing to suppress the development of retardation, select an acrylic polymer exhibiting negative birefringence so as to have a desired retardation. Can do. When the thermoplastic resin composition is used as a retardation film, since the thermoplastic resin composition is preferably positively birefringent, a positive birefringent fluorine-containing polymer such as polyvinylidene fluoride is used. When used, it is preferable to use a positive birefringent acrylic polymer.

  The mixture of the acrylic polymer and the fluorine-containing polymer is obtained by, for example, pre-blending the acrylic polymer and the fluorine-containing polymer with a conventionally known mixer such as an omni mixer. Can be carried out by extrusion kneading. In this case, the mixer used for extrusion kneading is not particularly limited, and for example, a conventionally known mixer such as an extruder such as a single screw extruder or a twin screw extruder or a pressure kneader can be used. .

  It is preferable to perform the process of filtering the said thermoplastic resin composition with a polymer filter after the said mixing process. By performing the step of filtering with a polymer filter, a thermoplastic resin composition with few foreign substances can be realized.

Specifically, the number of foreign substances in the thermoplastic resin composition is preferably 1,000 / m ² or less, more preferably 500 / m ² or less, having a particle diameter of 20 μm or more. More preferably, it is 200 / m ² or less, ideally 0 / m ² .

  The polymer filter preferably has a filtration accuracy in the range of 1 μm to 20 μm, more preferably in the range of 1 μm to 10 μm, and still more preferably in the range of 1 μm to 5 μm. If the filtration accuracy is less than 1 μm, the filtration residence time becomes long and the production efficiency is lowered, which is not preferable. In addition, when the filtration residence time is long, the thermoplastic resin or the like is likely to be thermally deteriorated, which may increase foreign matter. If the filtration accuracy exceeds 20 μm, foreign matter is likely to be mixed, which is not preferable.

  The polymer filter is not particularly limited as long as it has a filtration accuracy within the above range, and a conventionally known polymer filter can be used. Examples of the polymer filter include a leaf disk type polymer filter, a pack disk filter, a cylindrical filter, and a candle filter. Among these, a leaf disk type polymer filter is more preferable because a filtration area is wide and pressure loss is small even when a highly viscous resin is filtered.

  When the polymer filter is a leaf disk type polymer filter, the filter is made of a material obtained by sintering a metal fiber nonwoven fabric, a material made of a material obtained by sintering a metal powder, a product obtained by laminating several metal meshes, etc. Can be mentioned. In these, what consists of the material which sintered the metal fiber nonwoven fabric is more preferable.

The filtration area with respect to the resin (thermoplastic resin composition) treatment amount per hour in the polymer filter is appropriately selected depending on the treatment amount, and is not particularly limited. For example, 0.001 to 0.15 m ² / It can be in the range of (kg / h).

  In the filtration with the polymer filter, the temperature of the thermoplastic resin composition is preferably 240 ° C. or higher, more preferably 260 ° C. or higher, and further preferably 270 ° C. or higher. Moreover, it is preferable that it is 310 degrees C or less, It is more preferable that it is 300 degrees C or less, It is still more preferable that it is 290 degrees C or less.

  The viscosity (when measured at a shear rate of 100 / s) of the thermoplastic resin composition during filtration with the polymer filter is preferably 500 Pa · s or less, more preferably 450 Pa · s or less, and 400 Pa · s or less. Further preferred.

  The residence time of the thermoplastic resin composition during filtration with the polymer filter is preferably 20 minutes or less, more preferably 10 minutes or less, and even more preferably 5 minutes or less. Moreover, the filter inlet pressure at the time of filtration with the polymer filter can be in the range of 3 to 15 MPa, for example, and the outlet pressure of the filter can be in the range of 0.3 to 10 MPa, for example. Moreover, it is preferable that the pressure loss in a filter exists in the range of 1-15 Mpa. If the pressure loss is less than 1 MPa, the resin tends to be biased in the flow path through the polymer filter, and the quality of the resin after filtration tends to deteriorate. Conversely, when the pressure loss exceeds 15 MPa, the filter is easily damaged.

  The thermoplastic resin composition according to the present embodiment has not only excellent transparency and heat resistance, but also has desired characteristics such as low colorability, mechanical strength, and molding processability. It is useful for applications such as prisms, optical films, optical fibers, and optical disks. Among these, it is more preferable to use the optical lens, the optical prism, and the optical film.

  The thermoplastic resin composition according to the present embodiment can be formed into various shapes depending on the application. Examples of shapes that can be formed include films, sheets, plates, disks, blocks, balls, lenses, rods, strands, cords, fibers, and the like. The molding method is not particularly limited as long as it is appropriately selected from conventionally known forming methods according to the shape.

  The thermoplastic resin composition according to the present embodiment may contain a polymer other than the acrylic polymer and the fluorine-containing polymer.

  Examples of the polymer other than the acrylic polymer and the fluorine-containing polymer include, for example, elastic organic fine particles and other polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, poly (4-methyl-1- Olefin polymers such as pentene); halogen-containing polymers such as vinyl chloride and chlorinated vinyl resins; polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer, etc. Polystyrene such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; polyamide such as nylon 6, nylon 66, nylon 610; polyacetal; polycarbonate; polyphenylene oxide; Polyphenylene sulfide, poly ether ketone; polysulfone; polyether sulfone; polyoxyethylene benzylidene alkylene; polyamideimide; and the like.

  In particular, when the acrylic polymer is the above-mentioned lactone ring-containing polymer, the thermoplastic resin composition exhibits positive birefringence (positive retardation), and therefore positive birefringence (positive position). From the viewpoint of increasing the phase difference), it is preferable to contain a polymer exhibiting positive birefringence (positive phase difference) such as vinyl chloride, polycarbonate, and other polymers containing an aromatic ring in the main chain.

  When the thermoplastic resin composition according to the present embodiment contains elastic organic fine particles, the content is preferably in the range of 0 to 49% by mass, more preferably in the range of 10 to 40% by mass, and still more preferably. Is in the range of 15 to 30% by mass. When the content ratio of the elastic organic fine particles exceeds 49% by mass, the transparency may decrease due to aggregation of the elastic organic fine particles, or foreign substances may be generated as a by-product, which may not be used for optical applications.

  The content ratio of the other polymer in the thermoplastic resin composition according to the present embodiment is preferably in the range of 0 to 49% by mass, more preferably in the range of 0 to 40% by mass, and still more preferably 0 to 0% by mass. It is in the range of 30% by mass, particularly preferably in the range of 0 to 20% by mass.

  The thermoplastic resin composition according to the present embodiment has the same birefringence code as that of the acrylic polymer in order to increase the retardation value (in some cases, retardation value or simply referred to as retardation). You may contain the low molecular substance which shows the birefringence of a code | symbol. The low molecular weight substance generally refers to a substance having a molecular weight of 5,000 or less, preferably 1,000 or less, and specifically includes a low molecular weight substance described in Japanese Patent No. 3696645.

  In particular, when the acrylic polymer is the above-described lactone ring-containing polymer, the resulting thermoplastic resin composition exhibits positive birefringence (positive retardation), and therefore positive birefringence (positive In view of increasing the retardation of the low molecular weight material, a low molecular weight material exhibiting positive birefringence (positive retardation) such as stilbene, biphenyl, diphenylacetylene, or a normal liquid crystal material is preferable.

  The content ratio of the low molecular weight substance in the thermoplastic resin composition according to the present embodiment is preferably in the range of 0 to 20% by mass, more preferably in the range of 0 to 10% by mass, and still more preferably 0 to 0% by mass. It is in the range of 5% by mass.

  Moreover, the thermoplastic resin composition according to the present embodiment may contain other additives. Examples of other additives include hindered phenol-based, phosphorus-based and sulfur-based antioxidants; light-resistant stabilizers, weather-resistant stabilizers, heat-stabilizers, and other stabilizers; reinforcing materials such as glass fibers and carbon fibers. UV absorbers such as phenyl salicylate, (2,2′-hydroxy-5-methylphenyl) benzotriazole, 2-hydroxybenzophenone; near infrared absorbers; tris (dibromopropyl) phosphate, triallyl phosphate, antimony oxide Flame retardants such as: antistatic agents such as anionic, cationic and nonionic surfactants; colorants such as inorganic pigments, organic pigments and dyes; organic fillers and inorganic fillers; resin modifiers; Inorganic fillers; plasticizers; lubricants; antistatic agents; flame retardants;

  The content of other additives in the thermoplastic resin composition according to the present embodiment is preferably in the range of 0 to 5% by mass, more preferably in the range of 0 to 2% by mass, and still more preferably 0 to 0% by mass. It is in the range of 0.5% by mass.

  The elastic organic fine particles (hereinafter referred to as “organic fine particles”) preferably have an effect of improving the physical properties of the thermoplastic resin composition such as flexibility (bending resistance). For this reason, it is more preferable that the organic fine particles have a crosslinked structure.

  The organic fine particles having a crosslinked structure can be obtained, for example, by polymerizing a monomer composition containing a polyfunctional compound having two or more nonconjugated double bonds per molecule.

  Examples of the polyfunctional compound include divinylbenzene, allyl methacrylate, allyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyl acrylate, 1,4-butanediol dimethacrylate, ethylene glycol dimethacrylate, triallylsia. Nurete, triallyl isocyanurate, diallyl phthalate, diallyl maleate, divinyl adipate, divinylbenzene ethylene glycol dimethacrylate, divinylbenzene ethylene glycol diacrylate, diethylene glycol dimethacrylate, diethylene glycol diacrylate -Triethylene glycol dimethacrylate, triethylene glycol diacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, Examples include lamethylol methane tetramethacrylate, tetramethylol methane tetraacrylate, dipropylene glycol dimethacrylate and dipropylene glycol diacrylate. These may be used alone. Two or more kinds may be used in combination.

  The organic fine particles may have a structure other than a structure obtained by polymerizing the polyfunctional compound (hereinafter referred to as a structure derived from the polyfunctional compound). The structure other than the structure derived from the polyfunctional compound is represented by (meth) acrylic acid ester, hydroxyl group-containing monomer, unsaturated carboxylic acid, and general formula (3) that constitute the above-described acrylic polymer. It is preferable to have a structure of a polymer structural unit (repeating structural unit) constructed by polymerizing at least one selected from the following monomers.

  Since the organic fine particles have the structure of the polymer structural unit constituting the acrylic polymer, the dispersibility of the organic fine particles in the acrylic polymer is improved and the transparency of the film is improved. In addition, it is possible to further suppress by-product formation of foreign matters caused by aggregation of organic fine particles. Thereby, the filtration process at the time of shaping | molding of a film etc. can be performed in a short time.

  The organic fine particles exhibit crosslinking elasticity when obtained by polymerizing a monomer composition containing the polyfunctional compound. Thereby, the flexibility of the molded film or the like is improved, and a film or the like having excellent moldability and bending resistance can be obtained.

  The organic fine particles are composed of a core part and a shell part obtained by further polymerizing (meth) acrylic acid ester as a shell part to a particulate polymer that becomes a core part within an average particle diameter of 0.01 μm to 1 μm. An organic fine particle having a multilayer structure, wherein a mass ratio of the core part to the shell part is in a range of 20:80 to 80:20, and the shell part is in a range of 5% by mass to 50% by mass. It is preferable that the structural unit of the monomer of 2- (hydroxymethyl) acrylic acid ester of the inside is included. Since the organic fine particles have a core / shell structure, they can be more uniformly dispersed in the acrylic polymer. In addition, the organic fine particles according to the present embodiment are organic fine particles having a crosslinked structure having an average particle diameter in the range of 0.01 μm or more and 1 μm or less, and in the range of 1% by mass or more and 100% by mass or less. It preferably contains a structural unit of a monomer of (hydroxymethyl) acrylate.

  As said 2- (hydroxymethyl) acrylic acid ester, the compound which has a structure represented by General formula (2) mentioned above is preferable, and 2- (hydroxymethyl) methyl acrylate is more preferable.

  The organic fine particle has a structure derived from a polyfunctional compound only in the central part (core), and the part surrounding the central part (shell) is compatible with the acrylic polymer constituting the retardation film. It is preferable to have a high structure. As a result, the organic fine particles can be more uniformly dispersed in the acrylic polymer, and by-products of foreign matters caused by aggregation of the organic fine particles can be further suppressed. Thereby, a filtration process can be performed in a shorter time. The organic fine particles having such a core-shell structure are, for example, the above-mentioned (meth) acrylic acid esters with the reactive functional group (double bond) left unreacted during the polymerization of the organic fine particles as a graft crossing point. , A hydroxyl group-containing monomer, an unsaturated carboxylic acid, and at least one selected from monomers represented by the general formula (3) can be obtained by graft polymerization. Hereinafter, the shell part and the core part of the core-shell structure will be described.

  The shell part is not particularly limited as long as the shell part has a high compatibility with the acrylic polymer constituting the thermoplastic resin composition. As a structure which comprises the shell part which has a structure with high compatibility with the said acrylic polymer, when acrylic polymer is a lactone ring containing polymer mentioned above, for example, 2- (hydroxymethyl) methyl acrylate (Hereinafter referred to as MHMA) and methyl methacrylate (hereinafter referred to as MMA), a structure constructed by polymerizing a monomer composition (hereinafter referred to as MHMA / MMA structure), cyclohexyl methacrylate (hereinafter referred to as MMA) , CHMA) and MMA, a structure constructed by polymerizing a monomer composition (hereinafter referred to as CHMA / MMA structure), benzyl methacrylate (hereinafter referred to as BzMA) and MMA. A structure constructed by polymerizing a monomer composition (hereinafter referred to as a BzMA / MMA structure), 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA) And a structure constructed by polymerizing a monomer composition comprising MMA (hereinafter referred to as HEMA / MMA structure), acrylonitrile (hereinafter referred to as AN) and styrene (hereinafter referred to as St). And a structure constructed by polymerizing the monomer composition (hereinafter referred to as AN / St structure).

  When the shell part has an MHMA / MMA structure, the ratio (mass ratio) of MHMA and MMA is preferably in the range of 5:95 to 50:50, and in the range of 10:90 to 40:60. More preferably. Within the above range, the compatibility with the lactone ring-containing polymer is good, and the organic fine particles can be uniformly dispersed in the lactone ring-containing polymer. In addition, in the case of the shell having the MHMA / MMA structure, it preferably includes a lactone ring structure. The lactone ring structure can be introduced by forming a shell and then lactonizing.

  When the shell has a CHMA / MMA structure, the ratio (mass ratio) between CHMA and MMA is preferably in the range of 5:95 to 50:50, and in the range of 10:90 to 40:60. More preferably. Within the above range, the compatibility with the lactone ring-containing polymer is good, and the organic fine particles can be uniformly dispersed in the lactone ring-containing polymer.

  When the shell has a BzMA / MMA structure, the ratio (mass ratio) of BzMA and MMA is preferably in the range of 10:90 to 60:40, and in the range of 20:80 to 50:50. More preferably. Within the above range, the compatibility with the lactone ring-containing polymer is good, and the organic fine particles can be uniformly dispersed in the lactone ring-containing polymer.

  When the shell has a HEMA / MMA structure, the ratio (mass ratio) between HEMA and MMA is preferably in the range of 2:98 to 50:50, and in the range of 5:95 to 40:60. More preferably. Within the above range, the compatibility with the lactone ring-containing polymer is good, and the organic fine particles can be uniformly dispersed in the lactone ring-containing polymer.

  When the shell has an AN / St structure, the ratio (mass ratio) between AN and St is preferably in the range of 5:95 to 50:50, and in the range of 10:90 to 40:60. More preferably. Within the above range, the compatibility with the lactone ring-containing polymer is good, and the organic fine particles can be uniformly dispersed in the lactone ring-containing polymer.

  In particular, when the acrylic polymer is the lactone ring-containing polymer described above, it exhibits positive birefringence (positive phase difference), and therefore it is difficult to reduce the positive birefringence. In the case where the shell having the BzMA / MMA structure or the MHMA / MMA structure is further a shell having the MHMA / MMA structure, the shell preferably contains a lactone ring structure.

  The core part is not particularly limited as long as it is a structure that exhibits the effect of improving the flexibility of the thermoplastic resin composition, and examples thereof include a structure having a crosslink. Moreover, as a structure which has bridge | crosslinking, it is preferable that it is a crosslinked rubber structure.

  The above-mentioned crosslinked rubber structure is a rubber having a main chain of a polymer having a glass transition point in the range of −140 ° C. to 25 ° C. and having elasticity by crosslinking between the main chains with a polyfunctional compound. Means the structure. Examples of the crosslinked rubber structure include structures of acrylic rubber, polybutadiene rubber, and olefin rubber (repeating structural unit).

  As a structure which has the said bridge | crosslinking, the structure derived from the polyfunctional compound mentioned above is mentioned, for example. Among the polyfunctional compounds, 1,4-butanediol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, divinylbenzene, allyl methacrylate, allyl acrylate, and dicyclopentenyl methacrylate are more preferable.

  The amount of the polyfunctional monomer used in the production of the core part is preferably within the range of 0.01 to 15% by mass of the monomer composition used, and is within the range of 0.1 to 10% by mass. More preferably, it is within. By using the polyfunctional monomer within the above range, the film obtained by molding the resulting resin composition exhibits good bending resistance.

  The ratio of the core part to the shell part is a mass ratio, and the core: shell is preferably in the range of 20:80 to 80:20, and more preferably in the range of 40:60 to 60:40. . If the core portion is less than 20% by mass, the bending resistance of the film formed from the organic fine particles obtained tends to deteriorate, and if it exceeds 80% by mass, the hardness and formability of the film tend to decrease.

  The core part may or may not have a cross-linked structure. Similarly, the shell part may or may not have a cross-linked structure, but only the core part. It is more preferable that has a cross-linked structure and the shell portion does not have a cross-linked structure.

  The average particle size of the organic fine particles is preferably in the range of 0.01 to 1 μm, more preferably in the range of 0.03 to 0.5 μm, and in the range of 0.05 to 0.3 μm. It is particularly preferred. When the average particle size is less than 0.01 μm, there is a tendency that sufficient flexibility cannot be obtained when a film is formed. When the average particle size exceeds 1 μm, it is used as a filter in a filtration process during film production. Organic fine particles tend to be clogged. The particle size of the organic fine particles can be measured using a commercially available particle size distribution measuring device (for example, a particle size distribution measuring device (Submicron Particle Sizer NICOMP380) manufactured by NICOMP).

  The method for producing the organic fine particles is not particularly limited, and the monomer composition described above can be obtained by the conventionally known emulsion polymerization method, emulsion-suspension polymerization method, suspension polymerization method, bulk polymerization method or solution polymerization method. The organic fine particles can be produced by polymerization in stages or multiple stages. Among these, the emulsion polymerization method is more preferable.

  When producing organic fine particles by emulsion polymerization, the organic fine particles are aggregated by salting out or reprecipitation of the polymer solution after emulsion polymerization, and then filtered and washed. After washing, the organic fine particles are dried and mixed with an acrylic polymer and a fluorine-containing polymer to produce a thermoplastic resin composition. In addition, after washing, without drying the organic fine particles, the resulting organic fine particle cake is redispersed in an organic solvent such as MIBK (methyl isobutyl ketone), and the redispersed liquid contains an acrylic polymer and a fluorine-containing polymer. The dissolved or re-dispersed liquid is mixed with an acrylic polymer and a fluorine-containing polymer solution (a solution obtained by dissolving an acrylic polymer and a fluorine-containing polymer with an organic solvent), and then water and / or an organic solvent is added. The thermoplastic resin composition can also be produced by devolatilization.

  As the polymerization initiator during the polymerization of the organic fine particles, conventionally known initiators such as organic peroxides, inorganic peroxides, and azo compounds can be used. Specifically, for example, t-butyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, succinic acid peroxide, peroxymaleic acid t-butyl ester, cumene hydroper Organic peroxides such as oxide and benzoyl peroxide, inorganic peroxides such as potassium persulfate and sodium persulfate, oil solubility such as azobis (2-methylpropionamidine) dihydrochloride, azobisisobutyronitrile An initiator etc. are mentioned. These may be used alone or in combination of two or more.

  The above polymerization initiator is combined with a reducing agent such as sodium sulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, ascorbic acid, hydroxyacetone acid, ferrous sulfate, ferrous sulfate and disodium ethylenediaminetetraacetate. It may also be used as a normal redox type initiator.

  The organic peroxide can be added by a known addition method such as a method of adding to a polymerization system as it is, a method of adding a mixture to a monomer, a method of adding a dispersion in an aqueous emulsifier solution, and the like. From the viewpoint of transparency, a method of adding a mixture to a monomer or a method of adding it by dispersing in an aqueous emulsifier solution is preferable.

  In addition, the organic peroxide is an inorganic reducing agent such as a divalent iron salt and / or formaldehyde sulfoxylate soda, reducing sugar, ascorbic acid and the like from the viewpoint of polymerization stability and particle size control. It is preferable to use it as a redox initiator combined with an organic reducing agent.

  The surfactant used for the emulsion polymerization is not particularly limited, and a conventionally known surfactant for emulsion polymerization can be used. Specifically, for example, anionic surfactants such as sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium dioctyl sulfosuccinate, sodium lauryl sulfate, sodium fatty acid, alkylphenols, aliphatic alcohols, etc. And nonionic surfactants such as reaction products of olefins with propylene oxide and ethylene oxide. These surfactants may be used alone or in combination of two or more. Furthermore, if necessary, a cationic surfactant such as an alkylamine salt may be used.

  The resulting latex of organic fine particles can be separated and recovered by ordinary coagulation, washing and drying operations, or by treatment by spray drying, freeze drying or the like.

  One kind of the organic fine particles described above may be contained in the retardation film, or two or more kinds thereof may be contained.

(IV) Film The film according to the present embodiment can be obtained by mixing the thermoplastic resin composition and, if necessary, other components by a conventionally known mixing method and forming into a film shape. Moreover, it is good also as a stretched film by extending | stretching.

  As a matter of course, instead of the thermoplastic resin composition, an acrylic polymer or a fluorine-containing polymer contained in the thermoplastic resin composition may be used as a separate resin material.

  Examples of the other components include components other than the acrylic polymer and the fluorine-containing polymer described in the section “(III) Thermoplastic resin composition”.

  Examples of the film forming method include known film forming methods such as a solution casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method. Among these, the solution casting method (solution casting method) and the melt extrusion method are preferable.

  Solvents used in the solution casting method (solution casting method) include, for example, chlorinated solvents such as chloroform and dichloromethane; aromatic solvents such as toluene, xylene, benzene, and mixed solvents thereof; methanol, ethanol, and isopropanol , N-butanol, 2-butanol and the like alcohol solvents; methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethyl sulfoxide, dioxane, cyclohexanone, tetrahydrofuran, acetone, ethyl acetate, diethyl ether; These solvents may be used alone or in combination of two or more.

  Examples of the apparatus for performing the solution casting method (solution casting method) include a drum casting machine, a band casting machine, and a spin coater.

  Examples of the melt extrusion method include a T-die method and an inflation method, and the film forming temperature at that time is preferably in the range of 150 to 350 ° C., more preferably in the range of 200 to 300 ° C.

  In order to obtain a film exhibiting retardation performance (retardation film), it is important to orient molecular chains in the film, and any method can be used as long as the molecular chains can be oriented. . For example, various methods such as stretching, rolling, and take-up can be used. Among these, since production efficiency is high, it is preferable to develop retardation performance by stretching.

  As a stretching method for obtaining the retardation film, a conventionally known stretching method can be applied. For example, uniaxial stretching such as free-width uniaxial stretching and constant-width uniaxial stretching; biaxial stretching such as sequential biaxial stretching and simultaneous biaxial stretching; and a laminate by adhering a shrinkable film to one or both sides of the film during stretching A birefringent film in which molecular groups oriented in the stretching direction and the thickness direction are mixed by forming and heat-stretching the laminate and applying a shrinkage force in a direction perpendicular to the stretching direction to the film. Stretching to obtain. Biaxial stretching is preferable in that the bending resistance is improved. Furthermore, simultaneous biaxial stretching is preferred in that the bending resistance to any two orthogonal directions in the film plane is improved. Examples of the two orthogonal directions in the plane include a direction parallel to the slow axis in the film plane and a direction perpendicular to the slow axis in the film plane. In addition, what is necessary is just to set extending | stretching conditions, such as a draw ratio, extending | stretching temperature, an extending | stretching speed, etc. suitably according to a desired phase difference value and desired bending resistance, and extending | stretching conditions are not specifically limited.

  Further, when the refractive index in the slow axis direction in the film plane is nx, the refractive index in the direction perpendicular to nx in the film plane is ny, and the refractive index in the film thickness direction is nz, nx> ny = nz or nx = Free width uniaxial stretching is preferred in that a retardation film satisfying = nz> ny is obtained. Biaxial stretching is preferred in that a retardation film satisfying nx = ny> nz or nx = ny <nz can be obtained. Furthermore, in order to obtain a retardation film satisfying 0 <(nx−nz) / (nx−ny) <1 when nx> ny, stretching that imparts a shrinkage force in a direction perpendicular to the stretching direction to the film is obtained. The method is preferred.

  Examples of the stretching apparatus include a roll stretching machine, a tenter-type stretching machine, and a small experimental stretching apparatus such as a tensile testing machine, a uniaxial stretching machine, a sequential biaxial stretching machine, and a simultaneous biaxial stretching machine. The retardation film according to the present embodiment can be obtained using any of these apparatuses.

  The stretching temperature is preferably around the glass transition temperature of the film raw material polymer. Specifically, it is preferably performed within the range of (glass transition temperature −30) ° C. to (glass transition temperature +50) ° C., more preferably (glass transition temperature −20) ° C. to (glass transition temperature +20) ° C. Within the range, more preferably within the range of (glass transition temperature−10) ° C. to (glass transition temperature + 10) ° C. When it is lower than (glass transition temperature-30) ° C., a sufficient draw ratio cannot be obtained, which is not preferable. When the temperature is higher than (glass transition temperature + 50) ° C., resin flow occurs and stable stretching cannot be performed.

  The draw ratio defined by the area ratio is preferably in the range of 1.1 to 25 times, more preferably in the range of 1.2 to 10 times, and still more preferably in the range of 1.3 to 5 times. If it is smaller than 1.1 times, it is not preferable because it does not lead to the development of retardation performance accompanying to stretching and the improvement of toughness. When it is larger than 25 times, the effect on the increase in the draw ratio becomes small.

  When stretching in a certain direction, the stretching ratio for the one direction is preferably within a range of 1.05 to 10 times, more preferably within a range of 1.1 to 5 times, and even more preferably 1.2 to 3 times. Done within range. If it is smaller than 1.05 times, a desired phase difference value may not be obtained, which is not preferable. When the ratio is larger than 10 times, the effect on the increase in the stretching ratio is reduced, and the film may be broken during stretching.

  The stretching speed (one direction) is preferably in the range of 10 to 20,000% / min, more preferably in the range of 100 to 10,000% / min. If it is slower than 10% / min, it takes time to obtain a sufficient draw ratio, and the production cost is increased, which is not preferable. If it is faster than 20,000% / min, the stretched film may be broken, which is not preferable.

  The thickness of the retardation film according to the present embodiment is preferably in the range of 5 to 350 μm, more preferably in the range of 20 to 200 μm, and still more preferably in the range of 30 to 150 μm. When the film thickness is less than 5 μm, the strength is poor, and it is difficult to obtain a desired retardation value (retardation value). If the film thickness is larger than 350 μm, it is disadvantageous for thinning the liquid crystal display device.

  The retardation film according to the present embodiment preferably has an in-plane retardation value in the range of 20 to 500 nm at a wavelength of 589 nm per 100 μm thickness. More preferably, it exists in the range of 50-500 nm, More preferably, it exists in the range of 130-500 nm, Most preferably, it exists in the range of 170-500 nm, Most preferably, it exists in the range of 200-450 nm. If the thickness is smaller than 20 nm, the film thickness increases in order to obtain a desired retardation value (retardation value), which is not preferable. On the other hand, if it exceeds 500 nm, the retardation value (retardation value) changes due to a slight change in the stretching conditions, and it may be difficult to produce stably. Furthermore, in order to obtain a large retardation value, it is necessary to increase the stretching ratio and lower the stretching temperature, and the film may be broken during the stretching process, making it difficult to produce stably. is there.

  In the retardation film according to the present embodiment, the absolute value of the thickness direction retardation value at a wavelength of 589 nm per 100 μm thickness is preferably in the range of 30 to 400 nm. More preferably, it exists in the range of 70-400 nm, More preferably, it exists in the range of 120-350 nm, Most preferably, it exists in the range of 150-300 nm.

The “phase difference value” is also called a retardation value. The in-plane retardation value (Re) here is
Re = (nx−ny) × d
The thickness direction retardation value (Rth) is
Rth = [(nx + ny) / 2−nz] × d
Defined. In addition, nx represents the refractive index in the slow axis direction in the film plane, ny represents the refractive index in the direction perpendicular to nx in the film plane, nz represents the refractive index in the film thickness direction, and d represents the film thickness (nm). . The slow axis direction is a direction in which the refractive index in the film plane is maximum. Further, a material having a large refractive index in the stretching direction is said to have positive birefringence, and a material having a large refractive index in the direction perpendicular to the stretching direction in the film plane is said to have negative birefringence.

The “in-plane retardation value at a wavelength of 589 nm per thickness of 100 μm” is a value at d = 100 × 10 ³ nm in the above equation for obtaining the in-plane retardation value (Re). The “thickness direction retardation value at a wavelength of 589 nm per 100 μm thickness” is a value at d = 100 × 10 ³ nm in the above formula for obtaining the thickness direction retardation value (Rth). is there.

  The in-plane retardation value Re at 589 nm of the retardation film according to the present embodiment is preferably in the range of 20 nm to 1000 nm. More preferably, it exists in the range of 20-500 nm, More preferably, it exists in the range of 50-500 nm, Most preferably, it exists in the range of 100-350 nm.

  When the retardation film according to the present invention is used as a λ / 2 plate, Re at 589 nm is preferably in the range of 200 to 350 nm, more preferably in the range of 240 to 300 nm, and particularly preferably 260 to 280 nm. And most preferably within the range of 265 to 275 nm.

  When the retardation film according to this embodiment is used as a λ / 4 plate, Re at 589 nm is preferably in the range of 100 to 200 nm, more preferably in the range of 120 to 160 nm, and particularly preferably 130. It is in the range of ˜150 nm, most preferably in the range of 135 to 145 nm.

  The absolute value of the thickness direction retardation value (Rth) at 589 nm of the retardation film according to the present embodiment is preferably in the range of 10 nm to 500 nm. More preferably, it exists in the range of 50-400 nm, More preferably, it exists in the range of 100-300 nm.

  Whether the birefringence is positive or negative is determined by using a polarizing microscope described in “Introduction to Polarizing Microscopes for Polymer Materials” (Hiroshi Hiroya, Agne Technical Center Edition, Chapter 5, pp 78-82 (2001)). The determination can be performed by the additive color determination method using a / 4 plate. Further, the retardation film itself or the retardation film can be heated and shrunk and then uniaxially stretched to determine whether or not the refractive index in the stretching direction is increased.

  The film such as a retardation film according to the present embodiment preferably has a glass transition temperature in the range of 110 ° C to 200 ° C. More preferably, it is in the range of 115 ° C to 200 ° C, more preferably in the range of 120 ° C to 200 ° C, particularly preferably in the range of 125 ° C to 190 ° C, and most preferably in the range of 130 ° C to 180 ° C. When the temperature is less than 110 ° C., the heat resistance is insufficient for a severe use environment, and the film may be deformed to easily cause retardation unevenness. Moreover, when it exceeds 200 degreeC, it will become an ultra-high heat-resistant film, but since the moldability for obtaining this film is bad or the flexibility of a film may fall large, it is unpreferable.

  The film such as a retardation film according to the present embodiment preferably has a total light transmittance of 85% or more. More preferably, it is 90% or more, More preferably, it is 91%. The total light transmittance is a measure of transparency, and if it is less than 85%, the transparency is lowered and it is not suitable as an optical film.

  The film such as a retardation film according to the present embodiment preferably has a haze of 5% or less. More preferably, it is 3% or less, More preferably, it is 1% or less. When the haze exceeds 5%, the transparency is lowered and it is not suitable as an optical film.

  A film such as a retardation film according to the present embodiment can further control optical characteristics by being laminated with the same kind of optical material and / or different kind of optical material in addition to the use alone. Although it does not specifically limit as an optical material laminated | stacked in this case, For example, a polarizing plate, the stretched orientation film made from a polycarbonate, the stretched orientation film made from cyclic polyolefin, etc. are mentioned.

  A film such as a retardation film according to the present embodiment is suitably used as an optical compensation member for a liquid crystal display device. Specifically, for example, retardation films for LCD such as STN type LCD, TFT-TN type LCD, OCB type LCD, VA type LCD, IPS type LCD, etc .; 1/2 wavelength plate; 1/4 wavelength plate; reverse wavelength Dispersion characteristic film; optical compensation film; color filter; laminated film with polarizing plate; polarizing optical compensation film. Moreover, the use which applied the retardation film which concerns on this Embodiment is not restrict | limited to these.

  In addition, the specific method of each analysis mentioned by description in embodiment mentioned above is demonstrated in a following example.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to a following example.

<Dynamic TG>
The polymer (or polymer solution or pellet) is once dissolved or diluted in tetrahydrofuran, poured into excess hexane or methanol for reprecipitation, and the taken out precipitate is vacuum dried (1 mmHg (1.33 hPa), 80 ° C. Volatile components and the like were removed by conducting the reaction for 3 hours or more, and the obtained white solid resin was analyzed by the following method (dynamic TG method).

Measuring apparatus: Thermo Plus2 TG-8120 Dynamic TG (manufactured by Rigaku Corporation)
Measurement conditions: Sample amount 5 to 10 mg
Temperature increase rate: 10 ° C / min
Atmosphere: Nitrogen flow 200ml / min
Method: Step-like isothermal control method (controlled at a weight reduction rate value of 0.005% / sec or less between 60 ° C and 500 ° C)
<Weight average molecular weight>
The weight average molecular weight of the polymer was determined by polystyrene conversion of GPC (GPC system manufactured by Tosoh Corporation, chloroform solvent). The weight average molecular weight of the fluorine-containing polymer was measured using DMF as a solvent.

<Thermal analysis of resin and film>
Thermal analysis of resin, film, etc. is performed using DSC (manufactured by Rigaku Corporation, apparatus name: DSC-8230) under conditions of about 10 mg of sample, a heating rate of 10 ° C./min, and a nitrogen flow of 50 cc / min. It was. The glass transition temperature (Tg) was determined by the midpoint method according to ASTM-D-3418.

<Melt flow rate>
The melt flow rate was measured at a test temperature of 240 ° C. and a load of 10 kg based on JIS K6874.

<Optical characteristics>
The retardation value per 100 μm of film thickness at a wavelength of 589 nm was determined from the value of the in-plane retardation value (Re) measured using KOBRA-WR manufactured by Oji Scientific Instruments.

  The average refractive index of the film measured with an Abbe refractometer, the film thickness d, the slow axis as the tilt central axis, and the incident angle of 40 ° are input, and the in-plane retardation value (Re) and the thickness direction retardation value ( Rth), a retardation value (Re (40 °)) measured by tilting by 40 ° with the slow axis as the tilt axis, and three-dimensional refractive indexes nx, ny, and nz were obtained.

  The total light transmittance and haze were measured using NDH-1001DP manufactured by Nippon Denshoku Industries Co., Ltd. The refractive index was measured in accordance with JIS K 7142 using a refractometer (manufactured by Atago Co., Ltd., apparatus name: Digital Abbe refractometer DR-M2) with respect to a measurement wavelength of 589 nm.

<Thickness of film>
Measurement was performed using a Digimatic Micrometer (manufactured by Mitutoyo Corporation).

<Cutter cutting property>
Cutter cutting performance of the film is “○” for a state where the film can be cut without a crack at the cut portion with a cutter knife in an atmosphere of 25 ° C. and 65% RH, and “× ".

<Content of lactone ring structural unit>
The dealcoholization reaction rate (lactone cyclization rate) is determined based on the weight loss that occurs when all hydroxyl groups are dealcoholated as methanol from the polymer composition obtained by polymerization, before the weight reduction starts in dynamic TG measurement. Was determined from the weight loss due to the dealcoholization reaction from 150 ° C. to 300 ° C. before the decomposition of the polymer started.

That is, in the dynamic TG measurement of the polymer having a lactone ring structure, the weight reduction rate between 150 ° C. and 300 ° C. is measured, and the obtained actual weight reduction rate is defined as (X). On the other hand, from the composition of the polymer, all the hydroxyl groups contained in the polymer composition are involved in the formation of the lactone ring, so that it becomes an alcohol and is dealcoholized. (Y) is the weight loss rate calculated on the assumption that the% dealcoholization reaction has occurred. The theoretical weight reduction rate (Y) is more specifically the molar ratio of raw material monomers having a structure (hydroxyl group) involved in the dealcoholization reaction in the polymer, that is, the raw material unit in the polymer composition. It can be calculated from the content of the monomer. These values (X, Y) are calculated from the dealcoholization formula:
1- (actual weight reduction rate (X) / theoretical weight reduction rate (Y))
Substituting into, the value is obtained and expressed in% to obtain the dealcoholization reaction rate.

  As an example, the proportion of the lactone ring structure in the pellet (A-1) obtained in Production Example 1 described later is calculated.

  When the theoretical weight loss rate (Y) of this polymer was determined, the molecular weight of methanol was 32, the molecular weight of methyl 2- (hydroxymethyl) acrylate was 116, and methyl 2- (hydroxymethyl) acrylate. Since the content (weight ratio) in the polymer before lactone cyclization of the structure derived from the composition is 20.0 mass%, it is (32/116) × 20.0≈5.52 mass%. On the other hand, the actual weight loss rate (X) by dynamic TG measurement was 0.17% by mass. When these values are applied to the above-described dealcoholization calculation formula, 1− (0.17 / 5.52) ≈0.969 is obtained, so that the dealcoholization reaction rate is 96.9%.

Then, assuming that the lactone cyclization reaction was performed by the amount corresponding to the dealcoholization reaction rate, the content ratio (mass%) of the following formula lactone ring = B × A × M _R / M _m
(Wherein, B is in the lactone cyclization previous polymer is the mass proportion of the raw material monomer structural units having the structure (hydroxyl group) responsible for the lactonization, M _R lactone ring structure units to produce M _m is the molecular weight of the raw material monomer having a structure (hydroxyl group) involved in lactone cyclization, and A is the dealcoholization reaction rate)
Thus, the lactone ring content ratio can be calculated.

  For example, in the case of Production Example 1 described later, the content of the structure derived from methyl 2- (hydroxymethyl) acrylate in the polymer before lactone cyclization of the acrylic resin is 20.0% by mass, and the calculated dealcoholization reaction rate Is 96.9%, and the formula weight of the lactone ring structural unit produced when methyl 2- (hydroxymethyl) acrylate having a molecular weight of 116 is condensed with methyl methacrylate is 170. Therefore, the lactone ring in the acrylic resin The content ratio of is 28.4 (= 20.0 × 0.969 × 170/116) mass%.

[Production Example 1] Production of acrylic polymer pellet (A-1) To a 30 L reaction kettle equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introduction pipe, 8,000 g of methyl methacrylate (MMA), 2- (Hydroxymethyl) methyl acrylate (MHMA) (2,000 g) and toluene (10,000 g) were charged, and the temperature was raised to 105 ° C. while introducing nitrogen. After the start of reflux, 10.0 g of t-amyl peroxyisononanoate (trade name: Lupazole 570, manufactured by Atofina Yoshiaki Co., Ltd.) was added as an initiator, and at the same time, 20.0 g of t-amyl peroxyisononanoate and toluene were added. While an initiator solution consisting of 100 g was added dropwise over 2 hours, solution polymerization was performed under reflux (about 105 to 110 ° C.). After completion of the dropwise addition of the initiator solution, aging was performed for an additional 4 hours. The polymerization reaction rate was 96.6%, and the content of the structure derived from methyl 2- (hydroxymethyl) acrylate in the polymer was 20.0% by mass.

  10 g of stearyl phosphate / distearyl phosphate mixture (trade name: Phoslex A-18, manufactured by Sakai Chemical Co., Ltd.) was added, and the cyclization condensation reaction was performed under reflux (about 85 to 105 ° C.) for 2 hours. The cyclocondensation reaction was performed for 1.5 hours under pressure in an autoclave using a medium (gauge pressure was about 1.6 MPa at maximum).

  The polymer solution obtained by the above cyclization condensation reaction is a bent type screw having a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1, and a forevent number of 4. It is introduced into a twin-screw extruder (φ = 29.75 mm, L / D = 30) at a processing rate of 2.0 kg / hour in terms of resin amount, and a cyclization condensation reaction and devolatilization are carried out in the extruder. The transparent pellet (A-1) was obtained by taking out.

  The weight average molecular weight of the obtained pellet (A-1) was 148,000, the melt flow rate was 11.0 g / 10 min, and the glass transition temperature was 130 ° C. Further, when the dynamic Tg was measured, a weight loss of 0.17% by mass was detected.

[Production Example 2] Production of acrylic polymer pellet (A-2) To a 30 L reaction kettle equipped with a stirrer, a temperature sensor, a cooling tube, and a nitrogen introduction tube, 7,000 g of methyl methacrylate (MMA), 2- (Hydroxymethyl) methyl acrylate (MHMA) 3,000 g, mixed solvent (weight ratio 9: 1) 6,667 g consisting of methyl isobutyl ketone (MIBK) and methyl ethyl ketone (MEK) was charged, and nitrogen was introduced into the mixture. The temperature was raised to ° C. After the start of reflux, 6.0 g of t-amylperoxyisononanoate (trade name: Lupazole 570, manufactured by Atofina Yoshitomi Corp.) was added as an initiator, and at the same time, 12.0 g of t-amylperoxyisonononate, MIBK. Solution polymerization was carried out under reflux (about 95 to 110 ° C.) while adding an initiator solution consisting of 3,315 g of a mixed solvent (weight ratio: 9: 1) consisting of MEK and MEK over 3 hours. After dropwise addition of the initiator solution, aging was performed for an additional 4 hours. The polymerization reaction rate was 94.5%, and the content of the structure derived from methyl 2- (hydroxymethyl) acrylate in the polymer was 29.7% by mass.

  To the resulting polymer solution, 20 g of an octyl phosphate / dioctyl phosphate mixture (trade name: Phoslex A-8, manufactured by Sakai Chemical Co., Ltd.) was added and subjected to a cyclization condensation reaction under reflux (about 85 to 100 ° C.) for 2 hours. Furthermore, a cyclization condensation reaction was performed for 1.5 hours under pressure in an autoclave using a heating medium at 240 ° C. (gauge pressure was about 2 MPa at maximum).

  The polymer solution obtained by the above cyclization condensation reaction is a bent type screw having a barrel temperature of 260 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa (10 to 300 mmHg), a rear vent number of 1, and a forevent number of 4. It is introduced into a twin-screw extruder (φ = 29.75 mm, L / D = 30) at a processing rate of 2.0 kg / hour in terms of resin amount, and a cyclization condensation reaction and devolatilization are carried out in the extruder. The transparent pellet (A-2) was obtained by taking out.

  The weight average molecular weight of the obtained pellet (A-2) was 127,000, the melt flow rate was 6.5 g / 10 min, and the glass transition temperature was 140 ° C. Further, when the dynamic Tg was measured, a weight loss amount of 0.25% by mass was detected.

[Example 1]
Pellet (A-1) obtained in Production Example 1 and polyvinylidene fluoride (PVDF) resin (trade name: KF Polymer KF # 1000, manufactured by Kureha Chemical Industries, Ltd., weight average molecular weight: 242,000) A transparent pellet (B-1) was obtained by kneading using a twin screw extruder (φ = 20 mm) at a weight ratio of pellet (A-1) / PVDF resin = 90/10.

  The obtained pellet (B-1) was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm) to produce a film (C-1) having a thickness of about 140 μm. . The film (C-1) was uniaxially stretched twice at a stretching temperature of 125 ° C. and a rate of 400% / min to obtain a stretched film (D-1) having a thickness of 100 μm. Various analysis results are shown in Table 2.

[Example 2]
The pellet (A-2) obtained in Production Example 2 and a polyvinylidene fluoride (PVDF) resin (trade name: KF Polymer KF # 1000, manufactured by Kureha Chemical Industries, Ltd., weight average molecular weight: 242,000), A transparent pellet (B-2) was obtained by kneading using a twin screw extruder (φ = 20 mm) at a weight ratio of pellet (A-2) / PVDF resin = 90/10.

  The obtained pellet (B-2) was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm) to produce a film (C-2) having a thickness of about 140 μm. . The film (C-2) was stretched uniaxially at a stretching temperature of 134 ° C. and a rate of 400% / min to obtain a stretched film (D-2) having a thickness of 100 μm. Various analysis results are shown in Table 2.

Example 3
The pellet (A-2) obtained in Production Example 2 and a polyvinylidene fluoride (PVDF) resin (trade name: KF Polymer KF # 1000, manufactured by Kureha Chemical Industries, Ltd., weight average molecular weight: 242,000), A transparent pellet (B-3) was obtained by kneading using a twin screw extruder (φ = 20 mm) at a weight ratio of pellet (A-2) / PVDF resin = 80/20.

  The obtained pellet (B-3) was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm) to produce a film (C-3) having a thickness of about 140 μm. . This film (C-3) was uniaxially stretched twice at a stretching temperature of 120 ° C. and a rate of 400% / min to obtain a stretched film (D-3) having a thickness of 100 μm. Various analysis results are shown in Table 2.

[Comparative Example 1]
The pellet (A-1) obtained in Production Example 1 was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm), and a film having a thickness of about 140 μm (C-4 ) Was produced. The film (C-4) was uniaxially stretched twice at a stretching temperature of 135 ° C. at a rate of 400% / min to obtain a stretched film (D-4) having a thickness of 100 μm. Various analysis results are shown in Table 2.

[Comparative Example 2]
The pellet (A-2) obtained in Production Example 2 was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm), and a film having a thickness of about 140 μm (C-5) ) Was produced. The film (C-5) was stretched uniaxially at a stretching temperature of 144 ° C. and a rate of 400% / min to obtain a stretched film (D-5) having a thickness of 100 μm. Various analysis results are shown in Table 2.

[Comparative Example 3]
The pellet (A-1) obtained in Production Example 1 and the acrylonitrile-styrene (AS) resin (trade name: Toyo AS AS20, manufactured by Toyo Styrene Co., Ltd.) were pelleted (A-1) / AS resin = 90 / A transparent pellet (B-6) was obtained by kneading using a twin screw extruder (φ = 20 mm) at a weight ratio of 10.

  The obtained pellet (B-6) was melt-extruded from a coat hanger type T die having a width of 150 mm using a single screw extruder (φ = 20 mm) to produce a film (C-6) having a thickness of about 140 μm. . The film (C-6) was uniaxially stretched twice at a stretching temperature of 131 ° C. and a rate of 400% / min to obtain a stretched film (D-6) having a thickness of 100 μm. Various analysis results are shown in Table 2.

  As shown in Table 2, the films of Examples 1 to 3 in which a resin composition containing a PVDF resin was formed into a film showed flexibility despite high Tg and a large retardation value. It was excellent in cutter cutting property as an index.

  On the other hand, the films of Comparative Examples 1 and 2 in which only an acrylic polymer was formed into a film had a high Tg and a large retardation value, but the cutter cutability, which is an indicator of flexibility, was poor. In Comparative Example 3 in which a resin composition containing an AS resin was formed into a film, Tg was high, but the retardation value was very small, and the cutter cutability, which is an index indicating flexibility, was also poor.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The thermoplastic resin composition according to the present invention is excellent in handleability and heat resistance. Therefore, it can be suitably used for a retardation film such as a liquid crystal display device.

Claims (8)

  A thermoplastic resin composition comprising an acrylic polymer having a glass transition temperature of 110 ° C. or higher and 200 ° C. or lower as a main component, and a fluorine-containing polymer. The content of the acrylic polymer is in the range of 75% by mass to 99% by mass,
2. The thermoplastic resin composition according to claim 1, wherein a content ratio of the fluorine-containing polymer is in a range of 1% by mass to 25% by mass.   The thermoplastic resin composition according to claim 1 or 2, wherein the fluorine-containing polymer is a polymer having a structure derived from vinylidene fluoride as a main component.   The thermoplastic resin composition according to any one of claims 1 to 3, wherein the acrylic polymer contains a lactone ring structure. The lactone ring structure is represented by the following general formula (1)
(In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. The organic residue may contain an oxygen atom.)
The thermoplastic resin composition according to claim 4, which has a structure represented by:   A film comprising the thermoplastic resin composition according to claim 1.   The film according to claim 6, wherein the film is a retardation film.   The film according to claim 7, wherein an in-plane retardation value at a wavelength of 589 nm per 100 μm thickness is 20 nm or more and 500 nm or less.