JP2005350593A - Transparent film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent film which has excellent transparency, toughness, surface hardness and other mechanical characteristics. <P>SOLUTION: This transparent film is characterized by comprising 50 to 99 wt.% of a maleimide-olefin copolymer comprising 40 to 60 mol.% of specific maleimide residue units and 60 to 40 mol.% of specified olefin residue units and having a number-average mol.wt. of 1×10<SP>3</SP>to 5×10<SP>6</SP>, especially preferably N-methylmaleimide-isobutene copolymer, N-phenylmaleimide-isobutene copolymer, or N-cyclohexylmaleimide-isobutene copolymer, and 50 to 1 wt.% of a graft copolymer prepared by grafting a specific monomer to rubber particles, especially preferably rubber particles having an average particle diameter of 0.01 to 1 μm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film excellent in transparency, toughness, surface hardness and other mechanical properties.

  Transparent films have been used in various applications for purposes such as packaging, surface protection, display, and laminated base. In recent years, replacement of transparent plastic films with hard plates such as glass and acrylic plates, which have been dominant as transparent materials in the electronics field, has been progressing. The reason is that, in these electronics fields, the characteristics required for transparent materials are not only high light transmittance, but also parts using transparent materials, equipment weight reduction, size reduction, cost reduction, design freedom, In order to meet the demands for higher performance, etc. As the transparent film, methacrylic resin (hereinafter abbreviated as PMMA), polyester (hereinafter abbreviated as PET), polycarbonate (hereinafter abbreviated as PC), polyethersulfone (hereinafter abbreviated as PES). ), Polyarylate (hereinafter abbreviated as PAR), norbornene resin and the like are well known.

  On the other hand, it is disclosed that a film made of a maleimide / olefin copolymer has characteristics such as excellent transparency and heat resistance (see, for example, Patent Document 1).

  In addition, a film composed of an N-substituted maleimide / olefin copolymer and an acrylonitrile / styrene copolymer has been proposed, and has excellent heat resistance and extremely low birefringence, and thus has characteristics suitable for optical applications. (For example, refer to Patent Document 2).

  Furthermore, it is disclosed that a resin composition comprising an N-substituted maleimide / olefin copolymer and an elastomer has characteristics such as excellent transparency, heat resistance, and toughness (see, for example, Patent Document 3). .

JP 09-328523 A

JP 2000-080240 A Japanese Patent No. 3214003

  However, PMMA film has excellent optical properties and surface hardness, but there are problems of poor heat resistance and toughness, and PET film can exhibit excellent mechanical properties, heat resistance and chemical resistance by stretching, The birefringence becomes very large due to the molecular orientation, and it cannot be used for optical applications that require low birefringence. PC films, PES films, and PAR films are excellent in toughness and heat resistance, but are not suitable for optical applications where low birefringence is required because of poor weather resistance and surface hardness and large birefringence. Norbornene-based resin films have high heat resistance and small birefringence, but have a problem of poor adhesion.

  And the film made from the maleimide / olefin copolymer proposed in Patent Document 1 has characteristics such as high transparency and excellent heat resistance, but because of poor toughness, handling properties during molding or after molding, etc. The problem remained.

  Further, the film made of N-substituted maleimide / olefin copolymer and acrylonitrile / styrene copolymer described in Patent Document 2 has features such as high transparency, excellent heat resistance, and very low birefringence. However, since the toughness is poor, problems remain in handling properties during molding or after molding.

  Furthermore, Patent Document 3 relates to a resin composition composed of an N-substituted maleimide / olefin copolymer and an elastomer, and no study has been made on a transparent film.

  As described above, the conventional transparent film has its advantages and disadvantages, and it is difficult to say that it should always satisfy the demand for advanced and complicated in recent years. The appearance was desired.

  Accordingly, an object of the present invention is to provide a transparent film excellent in transparency, heat resistance, toughness and other mechanical properties.

  As a result of intensive studies on the above problems, the present inventors have found that a film comprising an N-substituted maleimide / olefin copolymer and a graft copolymer having a specific molecular structure has high transparency, heat resistance, surface The present inventors have found that it is excellent in hardness and rigidity and further excellent in toughness, and has completed the present invention.

That is, the present invention comprises 40 to 60 mol% of units represented by the following general formula (I) and 60 to 40 mol% of units represented by the following general formula (II), and the number average molecular weight is 1 × 10 ³ or more and 5 N-substituted maleimide / olefin copolymer 50 to 99% by weight of 10 ⁶ or less and at least selected from the group consisting of aromatic vinyl compound, acrylic acid alkyl ester, methacrylic acid alkyl ester and maleimide compound in rubber particles The present invention relates to a transparent film comprising 50 to 1% by weight of a graft copolymer obtained by graft polymerization of one or more monomers.

（Ｒ１は炭素数１〜６のアルキル基、炭素数３〜１２のシクロアルキル基、フェニル基、アルキル基置換フェニル基、ナフチル基から選ばれる少なくとも１種以上の有機基を示す。）

(R1 represents at least one organic group selected from an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, an alkyl group-substituted phenyl group, and a naphthyl group.)

（Ｒ２、Ｒ３は各々独立して水素又は炭素数１〜６のアルキル基を示す。）
以下、本発明について詳細に説明する。

(R2 and R3 each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)
Hereinafter, the present invention will be described in detail.

The N-substituted maleimide / olefin copolymer constituting the transparent film of the present invention is composed of 40 to 60 mol% of the unit represented by the general formula (I) and 60 to 40 mol of the unit represented by the general formula (II). % Having a number average molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less.

  R1 of the unit represented by the general formula (I) is at least one selected from an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, an alkyl group-substituted phenyl group, and a naphthyl group. When the organic group is a unit having an organic group other than these, the heat resistance of the resulting transparent film is inferior.

  Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, i-propyl group, i-butyl group, s- Examples thereof include a butyl group, a t-butyl group, and a 1,2-dimethylpropyl group. Examples of the cycloalkyl group having 3 to 12 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and an adamantyl group. Examples of the alkyl group-substituted phenyl group having 3 to 12 carbon atoms include 2-methylphenyl group, 2-ethylphenyl group, 2-n-propylphenyl group, 2-i-propylphenyl group, 2-n -Butylphenyl group, 2-s-butylphenyl group, 2-t-butylphenyl group, 2-n-pentylphenyl group, 2-t-pentylphenyl group, 2,6-dimethyl Ruphenyl group, 2,6-diethylphenyl group, 2,6-di-n-propylphenyl group, 2,6-di-i-propylphenyl group, 2-methyl-6-ethylphenyl group, 2-methyl-6 -I-propylphenyl group, 2,4,6-trimethylphenyl group, 2,4-dimethylphenyl group, and the like, and since it becomes a transparent film having excellent heat resistance and surface hardness, the general formula (I R1 of the unit represented by) is preferably a methyl group, a phenyl group, or a cyclohexyl group.

  Moreover, R2 and R3 of the unit represented by the general formula (II) are each independently hydrogen or an alkyl group having 1 to 6 carbon atoms, and when the carbon number exceeds 6, the heat resistance of the obtained transparent film Is inferior. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group, t-butyl group, pentyl group, hexyl group, cyclopropyl group, cyclobutyl group, A cyclohexyl group etc. can be mentioned, Among these, since it becomes a transparent film excellent in heat resistance and toughness especially, a methyl group is preferable.

  Such an N-substituted maleimide / olefin copolymer is, for example, a radical copolymer of a maleimide that derives a unit represented by the general formula (I) and an olefin that derives a unit represented by the general formula (II). It can be obtained by a polymerization reaction.

  In this case, examples of maleimides for deriving the unit represented by the general formula (I) include N-methylmaleimide, N-cyclohexylmaleimide, N-isopropylmaleimide, N-phenylmaleimide and the like. N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide are preferable because a transparent film having excellent hardness can be obtained.

  Examples of the olefins that derive the unit represented by the general formula (II) include olefins such as isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, and 2-methyl-1-hexene. Of these, isobutene is preferred because it is a transparent film having excellent heat resistance and toughness.

  Further, the unit represented by the general formula (I) constituting the N-substituted maleimide / olefin copolymer used in the present invention is in the range of 40 to 60 mol%, and in particular, a transparent film excellent in heat resistance and toughness. Therefore, the content is preferably 45 to 55 mol%. Here, when the unit represented by the general formula (I) exceeds 60 mol%, the resulting film becomes brittle. On the other hand, when it is less than 40 mol%, the heat resistance of the film is lowered.

The N-substituted maleimide / olefin copolymer used in the present invention has a number average molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less, and is particularly excellent in toughness and becomes a transparent film having high thickness accuracy. X 10 ⁴ or more and 5 x 10 ⁵ or less are preferable. When the number average molecular weight exceeds 5 × 10 ⁶ , the melt viscosity of the N-substituted maleimide / olefin copolymer becomes too high, and the fluidity of the N-substituted maleimide / olefin copolymer becomes poor, and the resulting film The thickness accuracy is inferior. On the other hand, when the number average molecular weight is less than 1 × 10 ³ , the toughness of the resulting film becomes poor. Here, the number average molecular weight in the present invention is a standard polystyrene conversion value obtained by gel permeation chromatography (GPC).

  The N-substituted maleimide / olefin copolymer used in the present invention is a transparent film particularly excellent in the balance of heat resistance, toughness, and surface hardness. Therefore, N-methylmaleimide / isobutene copolymer, N-phenyl It is preferably at least one N-substituted maleimide / olefin copolymer selected from the group consisting of a maleimide / isobutene copolymer and an N-cyclohexylmaleimide / isobutene copolymer.

  Furthermore, the N-substituted maleimide / olefin copolymer used in the present invention may contain units derived from other monomer components as long as the purpose of the present invention is not impaired. Examples of such other monomer components include styrene derivatives such as styrene and α-methylstyrene; methacrylic acid such as methacrylic acid, methyl methacrylate, and ethyl methacrylate, or esters thereof; acrylic acid, methyl acrylate. Acrylic acid such as ethyl acrylate or esters thereof; Vinyl esters such as vinyl acetate and vinyl benzoate; Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propio vinyl ether, and butyl vinyl ether; Maleic anhydride; Compounds such as acrylonitrile The content is 5 mol% or less There it is preferable.

  The N-substituted maleimide / olefin copolymer used in the present invention is obtained by known methods for obtaining maleimides for deriving units represented by the general formula (I) and olefins for deriving units represented by the general formula (II). It can be obtained by polymerization. As such a polymerization method, for example, it can be obtained by any of a bulk polymerization method, a solution polymerization method, a suspension polymerization method, a precipitation polymerization method, and an emulsion polymerization method, and among them, a film having particularly excellent transparency and color tone is obtained. Since it is obtained, it is preferable to be obtained by precipitation polymerization.

  As a polymerization initiator used in the polymerization reaction, for example, benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, organic peroxides such as t-butylperoxyacetate and t-butylperoxybenzoate; 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-butyronitrile), 2, Examples thereof include azo initiators such as 2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, and 1,1′-azobis (cyclohexane-1-carbonitrile).

  Examples of the solvent used in the solution polymerization method and the precipitation polymerization method include aromatic solvents such as benzene, toluene, and xylene; alcohol solvents such as methanol, ethanol, propyl alcohol, and butyl alcohol; cyclohexane, dioxane, tetrahydrofuran, acetone, and methyl ethyl ketone. , Dimethylformamide, isopropyl acetate, a mixed solvent of an aromatic solvent and an alcohol solvent, and the like.

  Although the polymerization temperature in that case can be suitably set according to the decomposition temperature of a polymerization initiator, generally it is preferable to carry out in 40-150 degreeC.

  Alternatively, the N-substituted maleimide / olefin copolymer can be obtained by post-imidizing the maleic anhydride / olefin copolymer with an amine compound as an alternative method.

  Such a post-imidation reaction includes, for example, maleic anhydride / olefin copolymer in an alcohol solvent such as methanol, ethanol and propanol; an aromatic solvent such as benzene and toluene; an ester solvent such as ethyl acetate and isopropyl acetate; Amidation reaction and imide by dissolving or dispersing in a mixed solvent of an aromatic solvent and an alcohol solvent, a solvent such as N-methyl-2-pyrrolidone, dimethylformamide, and reacting with an amine compound at a temperature of 50 to 250 ° C. It can be produced by a method of continuously performing an oxidization reaction, a method of reacting with an amine compound to obtain an amide, and then heating and dehydrating and ring-closing the amide to perform imidization.

  Examples of amine compounds include, for example, methylamine, cyclopropylamine, cyclobutylamine, cyclohexylamine, adamantylamine, aniline, 2-methylaniline, 2-ethylaniline, 2-n-propylaniline, 2-i-propylaniline, 2-n-butylaniline, 2-s-butylaniline, 2-t-butylaniline, 2-n-pentylaniline, 2-t-pentylaniline, 2,6-dimethylaniline, 2,6-diethylaniline, 2 , 6-Di-n-propylaniline, 2,6-di-i-propylaniline, 2-methyl-6-ethylaniline, 2-methyl-6-i-propylaniline, 2,4,6-trimethylaniline, 2,4-dimethylaniline, ethylamine, n-propylamine, n-butylamine, n-pent Examples include amine, n-hexylamine, i-propylamine, i-butylamine, s-butylamine, t-butylamine, 1,2-dimethylpropylamine, and among others, the balance of heat resistance, toughness, and surface hardness. Therefore, methylamine, aniline, and cyclohexylamine are preferable as the amine compound for deriving the unit represented by the general formula (I).

  The graft copolymer constituting the transparent film of the present invention contains at least one monomer selected from the group consisting of an aromatic vinyl compound, an alkyl acrylate ester, an alkyl methacrylate ester, and a maleimide compound on rubber particles. A graft copolymer obtained by graft polymerization. The graft copolymer is obtained by grafting a polymer comprising the monomer onto rubber particles, thereby improving the compatibility between the graft copolymer and the N-substituted maleimide / olefin copolymer. The dispersibility of the rubber particles in the N-substituted maleimide / olefin copolymer is good, and the film is excellent in transparency and toughness.

  The rubber particles are not particularly limited, and among them, since the film has excellent transparency and heat resistance, a conjugated diene homopolymer rubber, a monomer having copolymerizability with a conjugated diene, and It is preferably at least one rubber particle selected from the group consisting of a conjugated diene copolymer rubber with a conjugated diene and an acrylic rubber. Further, the rubber particles are more preferably partially cross-linked because they have excellent toughness when made into a transparent film. Further, the rubber particles may be a polyfunctional vinyl monomer, that is, a copolymer obtained by copolymerizing a monomer having a plurality of ethylenically unsaturated bonds. Generally, when a polyfunctional vinyl monomer is used, Crosslinking or graft reaction of rubber particles becomes easy, and the toughness of the transparent film becomes excellent.

  Examples of the conjugated diene include butadiene, isoprene, chloroprene, and examples of the monomer having copolymerizability with the conjugated diene include, for example, styrene, acrylonitrile, methacrylonitrile, acrylic acid alkyl ester, and methacrylic acid alkyl ester. As the rubber particles, 1,3-butadiene / styrene copolymer rubber, 1,3-butadiene rubber, and acrylic rubber are preferable because the film is particularly excellent in transparency and heat resistance.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, ethylstyrene, dimethylstyrene, pt-butylstyrene, vinylnaphthalene, 2,4-dimethylstyrene, Examples include styrene derivatives such as methoxystyrene, bromostyrene, fluorostyrene, hydroxystyrene, vinylxylene, aminostyrene, cyanostyrene, nitrostyrene, chloromethylstyrene, acetoxystyrene, p-dimethylaminomethylstyrene, vinylnaphthalene, and the like. You may use individually or in mixture of 2 or more types.

  Examples of the alkyl acrylate ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, amyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, dodecyl acrylate, and the like. These may be used alone or in combination of two or more.

  Examples of the alkyl methacrylate ester include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, cyclohexyl methacrylate, dodecyl methacrylate, and the like. These may be used alone or in combination of two or more.

  Examples of the maleimide compound include N-methylmaleimide, N-cyclohexylmaleimide, N-isopropylmaleimide, N-phenylmaleimide and the like, and these may be used alone or in combination of two or more.

  The graft copolymer is generally a polymer obtained by polymerizing at least one monomer selected from the group consisting of an aromatic vinyl compound, an acrylic acid alkyl ester, a methacrylic acid alkyl ester, and a maleimide compound. It is a graft copolymer bonded as a branch to rubber particles, and can be manufactured by a method known as a general method for manufacturing a graft copolymer. For example, emulsion polymerization method, solution containing at least one monomer selected from the group consisting of rubber particles, aromatic vinyl compounds, alkyl acrylates, alkyl methacrylates, maleimide compounds, radical polymerization initiators, solvents, etc. Examples of the polymerization method include suspension polymerization method, bulk polymerization method, and the like. Among these polymerization methods, the emulsion polymerization method is preferable because the graft copolymer is particularly easily produced. Further, the blending ratio of the rubber particles and the polymer to be branched in the graft copolymer is arbitrary, and among them, the rubber particles are particularly excellent in balance between heat resistance, toughness and surface hardness, and become a film with high thickness accuracy. : Polymer = 10-80: 90-20 (% by weight) is preferable.

  Specific examples of the emulsion polymerization method include, for example, rubber particles at a temperature of 0 to 100 ° C. in a deionized water in a nitrogen atmosphere, the monomer, an emulsifier, a dispersant, a polymerization initiator, a molecular weight as necessary. Examples thereof include a method of polymerizing by supplying a polymerization system at once, batchwise, or continuously with a regulator, a chain transfer agent, a pH regulator, and the like. Further, when the graft copolymer is obtained in a latex state, it is coagulated and separated by a conventionally known method, for example, an aggregation method using an electrolyte or a solvent or a freezing method in order to isolate the graft copolymer. It is preferable to use a method such as washing with water and drying.

  As the graft copolymer, a styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene is obtained because a film excellent in transparency and toughness can be obtained.・ Ethyl methacrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / ethyl acrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene Ethyl acrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / butyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / methacryl Butyl acrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / butyl acrylate copolymer- (1,3- Tadiene / styrene copolymer rubber) graft copolymer, styrene / butyl acrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / N-methylmaleimide copolymer- (1,3- Butadiene / styrene copolymer rubber) graft copolymer, styrene / N-methylmaleimide copolymer- (1,3-butadiene rubber) graft copolymer, styrene / N-phenylmaleimide copolymer- (1,3 -Butadiene / styrene copolymer rubber) Graft copolymer, Styrene / N-phenylmaleimide copolymer- (1,3-Butadiene rubber) graft copolymer, Styrene / ethyl methacrylate copolymer- (Acrylic rubber) Graft copolymer, styrene / ethyl acrylate copolymer-(acrylic rubber) graft copolymer, styrene / methacrylate Butyl acrylate copolymer- (acrylic rubber) graft copolymer, styrene / butyl acrylate copolymer- (acrylic rubber) graft copolymer, styrene / N-methylmaleimide copolymer- (acrylic rubber) graft copolymer It is preferably at least one graft copolymer selected from the group consisting of a polymer and a styrene / N-phenylmaleimide copolymer- (acrylic rubber) graft copolymer.

  Further, since the graft copolymer is a film particularly excellent in transparency and toughness, the average particle diameter of the rubber particles is preferably in the range of 0.01 to 1 μm, particularly 0.02 to 0.5 μm. It is preferable that it exists in the range. Further, since the graft copolymer is a film having particularly excellent transparency, the graft copolymer having a refractive index difference of 0.01 or less in absolute value with respect to the refractive index of the N-substituted maleimide / olefin copolymer. It is preferable that

  The transparent film of the present invention comprises 50 to 99% by weight of the N-substituted maleimide / olefin copolymer and 50 to 1% by weight of the graft copolymer, and is particularly high in transparency, heat resistance and surface. Since it is a film having an excellent balance of hardness and toughness and high thickness accuracy, it is composed of 60 to 99% by weight of the N-substituted maleimide / olefin copolymer and 40 to 1% by weight of the graft copolymer. preferable. Here, when the N-substituted maleimide / olefin copolymer is less than 50% by weight, the fluidity of the N-substituted maleimide / olefin copolymer is poor, and the thickness accuracy of the resulting film is poor. On the other hand, when the N-substituted maleimide / olefin copolymer exceeds 99% by weight, the toughness of the film becomes poor.

  In addition, since the transparent film of the present invention is a film having particularly high transparency and excellent balance between toughness and surface hardness, the aromatic film is further added to 100 parts by weight of the N-substituted maleimide / olefin copolymer. A transparent film comprising 1 to 50 parts by weight of a thermoplastic resin obtained by polymerizing at least one monomer selected from the group consisting of an aromatic vinyl compound, an acrylic acid alkyl ester, a methacrylic acid alkyl ester and a maleimide compound It is preferable that

  The thermoplastic resin can be obtained as a commercial product, for example, at least one or more kinds selected from the group consisting of the above-described aromatic vinyl compound, alkyl acrylate ester, alkyl methacrylate ester and maleimide compound. It can also be obtained by polymerizing the product by a method generally known as radical polymerization. In addition, since the thermoplastic resin at that time is a film having particularly excellent transparency, the difference in refractive index relative to the refractive index of the N-substituted maleimide / olefin copolymer is 0.01 or less in absolute value. A resin is preferred.

  When the transparent film of the present invention is used, the resin composition may be once composed of the N-substituted maleimide / olefin copolymer, the graft copolymer, and, optionally, the thermoplastic resin. Can be manufactured by performing general mixing and kneading, and examples of the mixing and kneading apparatus include a single screw extruder, a twin screw extruder, a brabender, a roll, a kneader, and a Banbury mixer. A melt kneader can be mentioned. Alternatively, a method may be used in which the respective components are dissolved or dispersed in a solvent and mixed. Furthermore, in the presence of at least one component, a method of producing another component from a raw material of the other component by a method such as modification or polymerization may be used.

  In order to suppress coloring, decomposition, cross-linking and the like due to heat history during production or molding, the transparent film of the present invention contains phenol, phosphorus, sulfur, and other antioxidants as necessary. It may be contained. These antioxidants may be used alone or in combination. Although the detail is shown below, this invention is not restrict | limited to these at all.

  Examples of phenolic antioxidants include pentaerythritol-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), thiodiethylene-bis (3- (3,5-di-t). -Butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N′-hexane-1,6-diylbis (3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionamide), diethyl ((3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) methyl) phosphate, 3,3 ′, 3 ′. ', 5,5', 5 ″ -hexa-t-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cresol, Renbis (oxyethylene) bis (3- (5-t-butyl-4-hydroxy-m-tolyl) propionate), hexamethylene-bis (3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate), 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5-tris ((4-tert-butyl-3-hydroxy-2,6-xylyl) methyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione 2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamino) phenol, 3,9-bis (2- (3- (3 -T-butyl-4-hydroxy-5-methylpheny ) Propionyloxy) -1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro (5,5) undecane, 2-t-butyl-6- (3-t-butyl-2-hydroxy-) 5-methylbenzyl) -4-methylphenyl acrylate, 2,4-di-t-butyl-6- (1- (3,5-di-t-butyl-2-hydroxyphenyl) ethyl) phenyl acrylate, 2, 4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like.

  Examples of phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorous Acid, tetrakis (2,4-di-t-butylphenyl) (1,1-biphenyl) -4,4'-diylbisphosphonite, bis (2,4-di-t-butylphenyl) pentaerythritol di Phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-diphosphite, bis (2,4-dicumylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-t-butylphenyl) ) (1,1-biphenyl) -4,4′-diylbisphosphonite, di-t-butyl-m-cresyl-phosphonite, etc. It is.

  Examples of the sulfur-based antioxidant include dilauryl-3,3-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3-thiodipropionate, and laurylstearyl-3,3. -Thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro (5,5) For example, undecane.

  Other antioxidants include, for example, 6- (3- (3) as a phenol / phosphorus antioxidant that is an antioxidant having both a function as a phenol-based antioxidant and a function as a phosphorus-based antioxidant. -T-butyl-4-hydroxy-5-methyl) propoxy) -2,4,8,10-tetra-t-butyldibenz (d, f) (1,3,2) -dioxaphosphine; vitamin E 3,4-dihydro-2,5,7,8-tetramethyl-2- (4,8,12-trimethyltridecyl) -2H-benzopyran-6-ol; a lactone-based antioxidant As 3- (3,4-dimethylphenyl) -5,7-di-t-butyl-3H-benzofuran-2-one.

  Among the above antioxidants, it is preferable to contain a phenolic antioxidant and a phosphorus antioxidant because the transparent film is particularly difficult to be colored. In that case, it is preferable to contain a phosphorus antioxidant in the ratio of 100-500 weight part with respect to 100 weight part of phenolic antioxidant, for example. Moreover, as content of antioxidant, it is preferable that it is 100-20000 ppm.

  In addition, when a transparent film is used as an optical film, it is assumed that the film is irradiated with light such as visible light, ultraviolet light, and infrared light. Especially when light is irradiated under a high temperature condition, thermal coloring and light deterioration are likely to occur. Therefore, for the purpose of suppressing the thermal coloring and photodegradation, a hindered amine light stabilizer, an ultraviolet absorber, a light stabilizer, a near infrared absorber and the like may be contained as necessary. Although the detail is shown below, this invention is not restrict | limited to these at all.

  As the hindered amine light stabilizer, those having a molecular weight of 1,000 or more are preferable because of excellent thermal coloring suppression effect. Furthermore, since the content of the hindered amine light stabilizer is excellent in the effect of preventing thermal coloring and the effect of light stabilization, it is preferably 100 to 15000 ppm.

  Examples of such a hindered amine light stabilizer include poly ((6-morpholino-s-triazine-2,4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl) imino) hexamethylene ( (2,2,6,6-tetramethyl-4-piperidyl) imino)), poly ((6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2, 4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6-tetramethyl-4-piperidyl) imino)), dibutylamine-1 , 3,5-triazine-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) 1,6-hexamethylenediamine and N- (2,2,6,6-tetra Methyl-4-piperidyl) buty Amine polycondensate, N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino ) -6-chloro-1,3,5-triazine condensate, dimethyl succinate-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine condensate and the like. .

  Examples of the ultraviolet absorber include conventionally known ultraviolet absorbers such as benzotriazole, benzophenone, triazine, benzoate, salicylic acid, acrylate, and metal complex. The content of the ultraviolet absorber is preferably 500 to 100,000 ppm.

  Examples of the ultraviolet absorber include compounds disclosed in JP-A No. 2001-98163, specifically phenyl salicylate, 4-t-butylphenyl salicylate, 2,4-di-t-butylphenyl- 3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, 4-t-octylphenyl salicylate, bis (4-t-butylbenzoyl) resorcinol, benzoylresorcinol, hesisadecyl-3 ′, 5′-di- t-butyl-4′-hydroxybenzoate, octadecyl-3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, 2-methyl-4,6-di-t-butylphenyl-3 ′, 5 ′ -Salicylate derivatives such as di-t-butyl-4'-hydroxybenzoate and mixtures thereof; 2,4-dihydride Xibenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane 2-hydroxybenzophenone derivatives such as 2,2 ′, 4,4′-tetrahydroxybenzophenone and mixtures thereof; 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (3 ′, 5′- Di-t-butyl-2'-hydroxyphenyl) benzotriazole, 2- (5'-t-butyl-2'-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) Benzotriazole, 2- (3-t-butyl-2-hydroxy- -Methylphenyl) -5-chlorobenzotriazole, 2- (3'-s-butyl-2'-hydroxy-5'-t-butylphenyl) benzotriazole, 2- (2'-hydroxy-4'-octyloxy) Phenyl) benzotriazole, 2- (3 ′, 5′-di-t-amyl-2′-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-bis (α, α-dimethyl) Benzyl) phenyl) -2H-benzotriazole, 2-((3′-t-butyl-2′-hydroxyphenyl) -5 ′-(2-octyloxycarbonylethyl) phenyl) -5-chlorobenzotriazole, 2- (3'-t-butyl-5 '-(2- (2-ethylhexyloxy) carbonylethyl) -2'-hydroxyphenyl) -5-chlorobenzo Riazole, 2- (3′-t-butyl-2′-hydroxy-5 ′-(2-methoxycarbonylethyl) phenyl) -5-chlorobenzotriazole, 2- (3′-t-butyl-2′-hydroxy) -5 ′-(2-methoxycarbonylethyl) phenyl) benzotriazole, 2- (3′-tert-butyl-2′-hydroxy-5- (2-octyloxycarbonylethyl) phenyl) benzotriazole, 2- (3 '-T-butyl-2'-hydroxy-5'-(2- (2-ethylhexyloxy) carbonylethyl) phenyl) benzotriazole, 2- (2-hydroxy-3- (3,4,5,6-tetrahydro) Phthalimidomethyl) -5-methylphenyl) benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5 Lorobenzotriazole, 2- (3′-dodecyl-2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (3′-t-butyl-2′-hydroxy-5 ′-(2-isooctyloxy) A mixture of carbonylethyl) phenyl) benzotriazole, 2,2′-methylenebis (6- (2H-benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutyl) phenol), 2, 2'-methylenebis (4-t-butyl-6- (2H-benzotriazol-2-yl) phenol), poly (3-11) (ethylene glycol) and 2- (3'-t-butyl-2'- Condensate with hydroxy-5 ′-(2-methoxycarbonylethyl) phenyl) benzotriazole, poly (3-11) (ethylene glycol) and methyl 3 A condensate with-(3- (2H-benzotriazol-2-yl) -5-t-butyl-4-hydroxyphenyl) propionate, 2-ethylhexyl-3- (3-t-butyl-5- (5- Chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl) propionate, octyl-3- (3-tert-butyl-5- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxy Phenyl) propionate, methyl-3- (3-t-butyl-5- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl) propionate, 3- (3-t-butyl-5- (5-Chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl) propionic acid, 2- (4,6-diphenyl-1,3,5-tri 2-yl) -5- (hexyl (oxy)) - phenol, and the like.

  As the near-infrared absorber, for example, cyanine-based near-infrared absorber, pyrylium-based near-infrared absorber, squarylium-based near-infrared absorber, croconium-based near-infrared absorber, azurenium-based near-infrared absorber, phthalocyanine-based near-infrared absorber, Examples include dithiol metal complex-based near-infrared absorbers, naphthoquinone-based near-infrared absorbers, anthraquinone-based near-infrared absorbers, indophenol-based near-infrared absorbers, and adi-based near-infrared absorbers.

  In addition, the transparent film of the present invention may contain a plasticizer as necessary within the range that does not impair the transparency, for the purpose of imparting surface smoothness, toughness, etc. Is usually preferably 20% by weight or less. These plasticizers may be used alone or in combination. Although the detail is shown below, this invention is not restrict | limited to these at all. Examples of the plasticizer include polyester plasticizers, epoxy plasticizers, phosphoric acid plasticizers, pyromellitic acid plasticizers, and trimellitic acid plasticizers.

  The polyester plasticizer may be one generally known as a polyester plasticizer, for example, a polycondensation of an aliphatic polybasic acid and / or an aromatic polybasic acid and a polyol, Further, it may be esterified with a terminal capping agent.

  The aliphatic polybasic acid is preferably an aliphatic polybasic acid having 2 to 20 carbon atoms or an ester-forming derivative thereof, such as oxalic acid, succinic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, sebacic acid, Examples thereof include aliphatic dibasic acids such as azelaic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid and octadecanedioic acid, and esters thereof. Further, aliphatic tribasic acids such as ethanetricarboxylic acid and propanetricarboxylic acid, and aliphatic tetrabasic acids such as butanetetracarboxylic acid can be used in combination. Examples of the ester-forming derivatives of these aliphatic polybasic acids include lower alkyl esters, acid halides, acid anhydrides and the like of these polybasic acids. These aliphatic polybasic acids or ester-forming derivatives thereof may be used alone or in combination of two or more.

  The aromatic polybasic acid is preferably an aromatic polybasic acid having 8 to 20 carbon atoms or an ester-forming derivative thereof, such as phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylmethane dicarboxylic acid, Aromatic dibasic acids such as sodium sulfoisophthalic acid or ester-forming derivatives thereof can be mentioned. In addition, aromatic polybasic acids such as trimesic acid, trimellitic acid and pyromellitic acid, or ester-forming derivatives thereof can also be used. These may be used alone or in combination of two or more.

  As the polyol, aliphatic alcohols having 2 to 20 carbon atoms are preferable. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,5-pentanediol, 3 Examples thereof include aliphatic dihydric alcohols such as methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, and polyethylene glycol. In addition, aliphatic polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol can be used in combination. These may be used alone or in combination of two or more.

  The terminal capping agent is preferably a monobasic acid having 2 to 20 carbon atoms or an ester-forming derivative thereof, and a monohydric alcohol having 1 to 18 carbon atoms. Examples of the monobasic acid having 2 to 20 carbon atoms include acetic acid and propion. And monobasic acids or ester-forming derivatives such as acid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, toluic acid, isononanoic acid, benzoic acid, dodecanoic acid, dimethylbenzoic acid, etc. One kind of monobasic acid or ester-forming derivative may be used, or two or more kinds may be used in combination. Examples of the monohydric alcohol having 1 to 18 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-hexanol, n-octanol, 2-ethylhexanol, n-dodecanol, tetradecanol, stearyl alcohol, and benzyl. Alcohol etc. can be mentioned, These monohydric alcohols may be used alone or in combination of two or more.

  Epoxy plasticizers such as epoxidized soybean oil, octyl epoxy stearate, etc .; phosphate ester types such as trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, trioleyl phosphate, Triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl phenyl phosphate, 2-ethylhexyl diphenyl phosphate, etc .; as trimellitic acid ester plasticizer, tri-2-ethylhexyl trimellitate, Triisodecyl trimellrate, etc .; Examples of the pyromellitic acid plasticizer include 2-ethyxyl pyromellilate.

  In addition to the above-mentioned components, the transparent film of the present invention requires pigments, lubricants, antiblocking agents, antistatic agents, surfactants, polymer electrolytes, conductive complexes, inorganic fillers, dyes, oils, and the like. It may be contained accordingly.

  Examples of the lubricant include aliphatic hydrocarbon lubricants such as liquid paraffin, natural paraffin and polyethylene wax; higher aliphatic alcohols and higher fatty acid lubricants such as cetyl alcohol, stearyl alcohol and stearic acid; stearamide, oleamide , Aliphatic amide type lubricants such as palmitic acid amide and methylene bisstearamide; metal soap type lubricants such as calcium stearate, zinc stearate, magnesium stearate and barium stearate; fatty acids such as butyl stearate and ethylene glycol stearate Examples include ester lubricants; silicone oils, and the like. The lubricant content is preferably 10,000 ppm or less.

  Examples of the method for producing the transparent film of the present invention include publicly known methods such as a casting method (solution casting method), a melt extrusion method, a calendar method, and a compression molding method. Solvents used in the casting method include chlorinated solvents such as chloroform and methylene chloride; aromatic solvents such as toluene, xylene, and mixed solvents thereof; methanol, ethanol, isopropanol, n-butanol, 2-butanol, and the like. Alcohol solvents: methyl cellosolve, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethyl sulfoxide, dioxane, methyl ethyl ketone, tetrahydrofuran, cyclohexanone, acetone, ethyl acetate, methyl acetate, ciethyl ether, acetonitrile, etc. can be used As the molding apparatus, a drum-type casting machine, a band-type casting machine, a spin coater, or the like can be used.

  Examples of the melt extrusion method include a T-die method and an inflation method. Further, the obtained film may be a stretched film by a stretching method, a tenter method that can be adopted as a biaxial stretching method, a tube method, a water tank stretching method as a uniaxial stretching method, a radiation stretching method, a hot air heating method, a hot plate heating method, Examples include a roll heating method.

  The thickness of the transparent film of the present invention is preferably 10 to 500 μm, and particularly preferably 10 to 200 μm because of excellent balance between mechanical properties and handling properties.

  The transparent film of the present invention may be coated with a thin film for the purpose of imparting functions such as gas barrier properties, scratch resistance and chemical resistance. That is, various thermoplastic resins; thermosetting resins having amino groups, imino groups, epoxy groups, silyl groups, etc .; radiation curable resins having acryloyl groups, methacryloyl groups, vinyl groups, etc .; Addition agent, wax, dispersant, pigment, solvent, dye, plasticizer, UV absorber, inorganic filler, etc., gravure roll coating method, Meyer bar coating method, reverse roll coating method, dip coating method, air knife coating method It can be applied by a method such as a calendar coating method, a squeeze coating method, a kiss coating method, a phanten coating method, a spray coating method, or a spin coating method. Furthermore, after coating, a cured thin film layer can be obtained by performing curing by irradiation with radiation or thermal curing by heating as necessary. In printing, a gravure method, an offset method, a flexo method, a silk screen method, or the like can be used. In addition, for the purpose of imparting gas sealability and the like, it may have a metal oxide layer mainly composed of aluminum, silicon, magnesium, zinc, etc., and the metal oxide layer may be formed by vacuum deposition, sputtering, ion It is preferably formed by a plating method, a plasma CVD method or the like.

  It is also possible to laminate with other films. As a method for laminating, any publicly known method may be used, for example, a heat bonding method such as a heat sealing method, an impulse sealing method, an ultrasonic bonding method, a high frequency bonding method; an extrusion laminating method or a hot melt laminating method. And laminating methods such as a dry laminating method, a wet laminating method, a solventless adhesive laminating method, a thermal laminating method, and a coextrusion method. As a film to be laminated, for example, polyester resin film, polyvinyl alcohol resin film, cellulose resin film, polyvinyl fluoride resin film, polyvinylidene chloride resin film, polyacrylonitrile resin film, nylon resin film, polyethylene resin film, polypropylene resin film Acetate resin film, polyimide resin film, polycarbonate resin film, polyacrylate resin film and the like.

  Since the transparent film of the present invention is excellent in adhesiveness, it has the characteristics that the surface treatment such as printing, painting, hard coating, antireflection coating, vacuum deposition, sputtering, antiglare coating and the like can be easily performed. Since it is excellent in heat resistance, surface hardness, toughness and the like, it can be suitably used as an optical film. Optical film, for example, retardation film, polarizing film protective film, reflector film, separator film, light diffusion film used in information equipment such as LCD, organic EL, PDP, copying machine, printer, facsimile, touch panel, optical file , Transparent electrode film substrate, display surface protective film, anti-glare film, anti-reflection film, electromagnetic wave shielding film, ultraviolet absorbing film, far infrared absorbing film, and the like.

Moreover, it can be used conveniently also as films other than the object for optics, for example, the following uses can be mentioned.
Recording field: electrostatic recording substrate, OHP, 2nd original, slide film, microfilm, X-ray film optical / magnetic memory field: Thermo-plastic recording, ferroelectric memory, magnetic tape, ID card, barcode prevention Fields: Meter windows, television cathode-ray tubes, clean room windows, semiconductor packaging materials, dust-proof films for photomasks, electromagnetic shielding fields: measuring instruments, medical equipment, radiation detectors, IC components, CRT
Photoelectric conversion element field: solar cell window, optical amplifier, photosensor heat ray reflection field: window (architecture, automobile, etc.), incandescent light bulb, cooking oven window, furnace viewing window, selective transmission film planar heating element field: defroster Aircraft, automobiles, freezers, incubators, goggles, medical equipment, liquid crystal display devices, electronic parts and circuit materials: capacitors, resistors, thin film composite circuits, leadless LSI chip carrier mounting, dry film resist electrode fields: paper batteries Electrode light transmission filter field: UV cut filter, UV transmission filter, UV transmission visible light absorption filter, color separation filter, color temperature conversion filter, neutral density filter, contrast filter, wavelength calibration filter, interference filter, infrared transmission filter, infrared Cut filter, heat ray Collection filter, heat ray reflection filter gas permselective membrane field: oxygen / nitrogen separation membrane, carbon dioxide separation membrane, hydrogen separation membrane Electrical insulation field: insulating adhesive tape, motor slot liner, transformer interphase insulation, lead insulation High voltage cable insulation coating polymer sensor field: optical sensor, infrared sensor, acoustic wave sensor, pressure sensor Surface protection field: CRT, furniture, system kitchen, automotive interior / exterior, paint protective film sliding material field: hopper chute Lining, sliding materials for conveyor belts, sliding materials for guide rails, paper feeding rollers for copiers, computer-mouse porous film fields: moisture permeable waterproof materials, filter materials for microfiltration membranes, etc. Other fields: energized thermal transfer, printer ribbons, Electric cable shield, water leakage prevention film, battery separation film

  The film obtained by the present invention is excellent in transparency, heat resistance, toughness, and other mechanical properties, and therefore can be suitably used as an optical film.

  EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

  Various physical properties shown in the examples were measured by the following methods.

~ Number average molecular weight ~
It calculated | required as a standard polystyrene conversion value by the elution curve of the N-substituted maleimide olefin copolymer measured using the gel permeation chromatography (GPC) (the Tosoh Corporation make, brand name HLC-802A).

~ Haze ~
The measurement was made according to JIS K7136.

~ Scratch pencil hardness ~
It measured based on JISK5600-5-4.

~ Elongation at break ~
Based on ASTM D882, the tensile elongation at break in the flow direction at the time of forming a transparent film was measured.

~ Tensile modulus ~
Based on ASTM D882, the tensile elastic modulus in the flow direction at the time of forming the transparent film was measured.

~ Refractive index ~
Based on ASTM D542, the measurement was performed under conditions of a measurement temperature of 25 ° C. and a measurement wavelength of 589 nm.

~ Average particle diameter of rubber particles ~
It measured using the laser diffraction type particle size distribution measuring apparatus (the Horiba make, brand name LA500).

Synthesis Example 1 (Synthesis of N-methylmaleimide / isobutene copolymer)
A stainless steel autoclave is filled with 100 parts by weight of maleic anhydride / isobutene copolymer (trade name Isoban 10 manufactured by Kuraray Co., Ltd.) and 500 parts by weight of N-methyl-2-pyrrolidone (hereinafter referred to as NMP) as a solvent. The maleic anhydride / isobutene copolymer was dissolved in NMP by stirring at room temperature. Next, after 40 parts by weight of methylamine was introduced at room temperature, the temperature was raised to 80 ° C. and stirred for 1 hour to carry out amidation reaction of maleic anhydride units. Subsequently, after the temperature was raised to 205 ° C. and the mixture was stirred for 1 hour to carry out an imidization reaction, the mixture was cooled to room temperature and reprecipitated using isopropanol to obtain a copolymer.

From the elemental analysis, infrared absorption spectrum measurement and ¹³ C-NMR measurement, the resulting copolymer was N-methylmaleimide residue / isobutene residue = 0.50 / 0.50 (molar ratio). It was confirmed to be an isobutene copolymer (hereinafter sometimes referred to as A-1). The number average molecular weight was 90000, and the refractive index was 1.5276.

Synthesis Example 2 (Synthesis of N-phenylmaleimide / isobutene copolymer)
A stainless steel autoclave was charged with 73 parts by weight of N-phenylmaleimide, 227 parts by weight of isobutene, 400 parts by weight of toluene, and 0.244 parts by weight of perbutyl neodecanoate as a polymerization initiator. After carrying out the polymerization reaction by stirring for 5 hours, the mixture was cooled to room temperature, filtered, washed and dried to obtain a copolymer.

^{From the 1} H-NMR measurement, the produced copolymer was N-phenylmaleimide / isobutene copolymer having N-phenylmaleimide residue / isobutene residue = 0.57 / 0.43 (molar ratio) (hereinafter referred to as A- 2))). The number average molecular weight was 90000, and the refractive index was 1.5706.

Synthesis Example 3 (Synthesis of 1,3-butadiene / styrene copolymer rubber particles)
A stainless steel autoclave was charged with 150 parts by weight of deionized water, 4 parts by weight of higher fatty acid soap and 0.075 parts by weight of sodium hydroxide, and the temperature was raised to 68 ° C. after purging with nitrogen. After adding 20% by weight of a monomer mixture consisting of 80 parts by weight of butadiene, 20 parts by weight of styrene and 0.3 part by weight of t-dodecyl mercaptan, separately prepared, potassium persulfate was added. The polymerization reaction was carried out by adding 135 parts by weight and stirring for 1 hour. Thereafter, the remaining 80% by weight of the monomer mixture was continuously added, and after completion of the addition, the temperature was raised to 80 ° C. and the mixture was further stirred for 1 hour to conduct a polymerization reaction. The synthesis | combination rubber particle (henceforth a rubber particle (B) may be described) was synthesize | combined. The average particle diameter of the obtained 1,3-butadiene / styrene copolymer rubber particles was 0.1 μm.
Synthesis Example 4 (Synthesis of styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer)
A stainless steel autoclave was charged with 100 parts by weight of the rubber particles (B) obtained in Synthesis Example 3 and 265 parts by weight of deionized water, and the temperature was raised to 70 ° C. Next, 0.32 parts by weight of potassium persulfate, 55 parts by weight of styrene, 45 parts by weight of ethyl methacrylate, 1.8 parts by weight of potassium rosinate soap, 0.44 parts by weight of potassium hydroxide and 27 parts by weight of deionized water were added. Then, after completion of the addition, the graft polymerization reaction was carried out by stirring for 30 minutes, and 2.5 parts by weight of an anti-aging agent was added to the graft copolymer. Then, it is added and coagulated in an aqueous magnesium sulfate solution heated to 95 ° C., and the coagulated product is washed with water and dried to give a styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft. A copolymer (hereinafter sometimes referred to as C-1) was obtained. The resulting styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer had a refractive index of 1.5298.

Synthesis Example 5 (Synthesis of styrene / butyl acrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer)
A stainless steel autoclave was charged with 100 parts by weight of the rubber particles (B) obtained in Synthesis Example 3 and 265 parts by weight of deionized water, and the temperature was raised to 70 ° C. Next, 0.32 parts by weight of potassium persulfate, 80 parts by weight of styrene, 20 parts by weight of butyl acrylate, 1.8 parts by weight of potassium rosinate soap, 0.44 parts by weight of potassium hydroxide and 27 parts by weight of deionized water were added. Then, after completion of the addition, the graft polymerization reaction was carried out by stirring for 30 minutes, and 2.5 parts by weight of an antioxidant was added to the graft copolymer. Then, it is added and coagulated in a magnesium sulfate aqueous solution heated to 95 ° C., and the coagulated product is washed with water and dried to give a styrene / butyl acrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft. A copolymer (hereinafter sometimes referred to as C-2) was obtained. The obtained styrene / butyl acrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer had a refractive index of 1.57331.

Synthesis Example 6 (Synthesis of styrene / ethyl methacrylate copolymer)
A stainless steel autoclave is charged with 100 parts by weight of deionized water, 45 parts by weight of styrene, 55 parts by weight of ethyl methacrylate, 0.02 parts by weight of di-t-butyl-p-cresol, and 0.2 parts by weight of sodium sulfate and stirred. The temperature was raised to 105 ° C. Next, 0.01 part by weight of di-t-butyl peroxide dissolved in a small amount of styrene was added. Thereafter, the temperature was raised to 145 ° C. and the polymerization reaction was carried out, followed by cooling to room temperature, filtration, washing and drying to obtain a copolymer.

^{From the 1} H-NMR measurement, the produced copolymer was a styrene / ethyl methacrylate copolymer (hereinafter referred to as D-1) having a styrene residue / ethyl methacrylate residue = 0.47 / 0.53 (molar ratio). It may be noted.) The number average molecular weight was 95,000 and the refractive index was 1.5315.

Synthesis Example 7 (Synthesis of styrene / butyl acrylate copolymer)
A stainless steel autoclave is charged with 100 parts by weight of deionized water, 75 parts by weight of styrene, 25 parts by weight of butyl acrylate, 0.02 parts by weight of di-t-butyl-p-cresol, and 0.2 parts by weight of sodium sulfate and stirred. The temperature was raised to 105 ° C. Next, 0.01 part by weight of di-t-butyl peroxide dissolved in a small amount of styrene was added. Thereafter, the temperature was raised to 145 ° C. and the polymerization reaction was carried out, followed by cooling to room temperature, filtration, washing and drying to obtain a copolymer.

^{From the 1} H-NMR measurement, the produced copolymer was a styrene / butyl acrylate copolymer (hereinafter referred to as D-2) having a styrene residue / butyl acrylate residue = 0.78 / 0.22 (molar ratio). It may be noted.) The number average molecular weight was 100,000 and the refractive index was 1.5722.

Example 1
90% by weight of N-methylmaleimide / isobutene copolymer obtained by Synthesis Example 1 and styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft obtained by Synthesis Example 4 10% by weight of the copolymer was blended and extruded through a 30 mmφ twin screw extruder (manufactured by Nippon Steel Works, trade name: TEX30) to obtain a resin composition.

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded on the conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to form a transparent film having a thickness of 100 μm. Obtained. Table 1 shows the results of physical properties measured using this transparent film.

Example 2
80% by weight of N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 2 and styrene / butyl acrylate copolymer ((1,3-butadiene / styrene copolymer rubber) graft obtained in Synthesis Example 5 20% by weight of the copolymer was blended and extruded through a 30 mmφ twin-screw extruder (manufactured by Nippon Steel Works, trade name: TEX30) to obtain a resin composition.

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded on the conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to form a transparent film having a thickness of 100 μm. Obtained. Table 1 shows the results of physical properties measured using this transparent film.

Example 3
Except that 90% by weight of the N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 is 80% by weight, and further 10% by weight of the styrene / ethyl methacrylate copolymer obtained in Synthesis Example 6 is blended. The resin composition and the transparent film were obtained by the same method as in Example 1 and evaluated.

  The results of measuring the physical properties are shown in Table 1.

Example 4
80% by weight of the N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 2 was set to 70% by weight, and the styrene / butyl acrylate copolymer obtained in Synthesis Example 5 (1,3-butadiene / styrene). Copolymer rubber) Same as Example 2 except that 20% by weight of graft copolymer was 15% by weight and 15% by weight of styrene / butyl acrylate copolymer obtained in Synthesis Example 7 was further blended. A resin composition and a transparent film were obtained by the method and evaluated.

  The results of measuring the physical properties are shown in Table 1.

Comparative Example 1
The N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 was extruded through a 30 mmφ twin-screw extruder (manufactured by Nippon Steel Works, trade name: TEX30) to obtain a transparent resin.

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded on the conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to form a transparent film having a thickness of 100 μm. Obtained. Table 2 shows the results of physical properties measured using this transparent film.

  The obtained transparent film had a low tensile elongation at break and was inferior in toughness.

Comparative Example 2
The N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 2 was extruded through a 30 mmφ twin-screw extruder (manufactured by Nippon Steel Works, trade name: TEX30) to obtain a transparent resin.

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded on the conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to form a transparent film having a thickness of 100 μm. Obtained. Table 2 shows the results of physical properties measured using this transparent film.

  The obtained transparent film had a low tensile elongation at break and was inferior in toughness.

Comparative Example 3
A 30 mmφ twin screw extruder comprising 90% by weight of the N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 and 10% by weight of 1,3-butadiene / styrene copolymer rubber particles obtained in Synthesis Example 3. The resin composition was obtained by extruding the product (made by Nippon Steel Works, trade name TEX30).

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded under conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to obtain a film having a thickness of 100 μm. . The results of measuring physical properties using this film are shown in Table 2.

  The obtained film had a large haze of 6.5%, was inferior in transparency, and had a scratched pencil hardness of 2B, inferior in hardness.

Comparative Example 4
A 30 mmφ twin screw extruder comprising 80% by weight of the N-phenylmaleimide / isobutene copolymer obtained in Synthesis Example 2 and 20% by weight of 1,3-butadiene / styrene copolymer rubber particles obtained in Synthesis Example 3. The resin composition was obtained by extruding the product (made by Nippon Steel Works, trade name TEX30).

  Next, the obtained resin composition was subjected to a twin-screw extruder provided with a T die, and extruded under conditions of a T die temperature of 270 to 285 ° C. and a cooling roll temperature of 100 to 130 ° C. to obtain a film having a thickness of 100 μm. . The results of measuring physical properties using this film are shown in Table 2.

  The obtained film had a large haze of 8.3%, inferior transparency, and scratched pencil hardness of 2B, which was inferior to the hardness.

Comparative Example 5
45% by weight of N-methylmaleimide / isobutene copolymer obtained by Synthesis Example 1 and styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft obtained by Synthesis Example 4 55% by weight of the copolymer was blended and extruded through a 30 mmφ twin screw extruder (manufactured by Nippon Steel Works, trade name: TEX30) to obtain a resin composition.

Next, the obtained resin composition was subjected to a twin-screw extruder equipped with a T die, extruded at a T die temperature of 270 to 285 ° C., and a cooling roll temperature of 100 to 130 ° C. Since the resin composition was remarkably inferior in fluidity, a film could not be obtained.
Comparative Example 6
A commercially available polycarbonate resin (manufactured by Teijin Chemicals Ltd., trade name L-1250Y) is subjected to a twin screw extruder equipped with a T die, and the temperature of the T die is 270 to 285 ° C and the temperature of the cooling roll is 100 to 130 ° C. A transparent film having a thickness of 100 μm was obtained by extrusion. Table 2 shows the results of physical properties measured using this transparent film. The polycarbonate film was inferior in rigidity and surface hardness.

Claims (7)

It consists of 40 to 60 mol% of units represented by the following general formula (I) and 60 to 40 mol% of units represented by the following general formula (II), and has a number average molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less. N-substituted maleimide / olefin copolymer 50 to 99% by weight, and at least one monomer selected from the group consisting of aromatic vinyl compounds, acrylic acid alkyl esters, methacrylic acid alkyl esters, and maleimide compounds in rubber particles A transparent film comprising 50 to 1% by weight of a graft copolymer obtained by graft polymerization of a body.

(R1 represents at least one organic group selected from an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, a phenyl group, an alkyl group-substituted phenyl group, and a naphthyl group.)

(R2 and R3 each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.) 2. The transparent film according to claim 1, wherein the rubber film is a graft copolymer having an average particle diameter of 0.01 to 1 [mu] m. A conjugated diene homopolymer rubber, a conjugated diene copolymer rubber of a conjugated diene and a monomer copolymerizable with a conjugated diene, and at least one rubber particle selected from the group consisting of acrylic rubber The transparent film according to claim 1 or 2. The transparent film according to claim 1, which is a graft copolymer having a refractive index difference of 0.01 or less as an absolute value with respect to the refractive index of the N-substituted maleimide / olefin copolymer. The N-substituted maleimide / olefin copolymer is at least one selected from the group consisting of N-methylmaleimide / isobutene copolymer, N-phenylmaleimide / isobutene copolymer, and N-cyclohexylmaleimide / isobutene copolymer. N-substituted maleimide / olefin copolymer, graft copolymer is styrene / ethyl methacrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / ethyl methacrylate copolymer Polymer- (1,3-butadiene rubber) graft copolymer, styrene / ethyl acrylate copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / ethyl acrylate copolymer Copolymer- (1,3-butadiene rubber) graft copolymer, styrene / methacrylic acid butyrate Copolymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / butyl methacrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / butyl acrylate copolymer Polymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / butyl acrylate copolymer- (1,3-butadiene rubber) graft copolymer, styrene / N-methylmaleimide copolymer Polymer- (1,3-butadiene / styrene copolymer rubber) graft copolymer, styrene / N-methylmaleimide copolymer- (1,3-butadiene rubber) graft copolymer, styrene / N-phenylmaleimide Copolymer-(1,3-Butadiene / Styrene Copolymer Rubber) Graft Copolymer, Styrene / N-Phenylmaleimide Copolymer 1,3-butadiene rubber) graft copolymer, styrene / ethyl methacrylate copolymer- (acrylic rubber) graft copolymer, styrene / ethyl acrylate copolymer- (acrylic rubber) graft copolymer, styrene / ethyl methacrylate copolymer Butyl methacrylate copolymer- (acrylic rubber) graft copolymer, styrene / butyl acrylate copolymer- (acrylic rubber) graft copolymer, styrene / N-methylmaleimide copolymer- (acrylic rubber) graft copolymer 5. The polymer according to claim 1, wherein the polymer is at least one graft copolymer selected from the group consisting of a styrene / N-phenylmaleimide copolymer- (acrylic rubber) graft copolymer. Transparent film. Further, at least one monomer selected from the group consisting of an aromatic vinyl compound, an alkyl acrylate ester, an alkyl methacrylate ester and a maleimide compound is polymerized with respect to 100 parts by weight of the N-substituted maleimide / olefin copolymer. The transparent film according to claim 1, comprising 1 to 50 parts by weight of a thermoplastic resin. The transparent film according to claim 6, which is a thermoplastic resin having an absolute difference in refractive index of 0.01 or less with respect to the refractive index of the N-substituted maleimide / olefin copolymer.