JP2005239758A - Transparent film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent film having excellent transparency, heat resistance, toughness and other mechanical characteristics. <P>SOLUTION: The transparent film is composed of 1-99 wt.% of a maleimide-olefin copolymer which is a copolymer composed of 40-60 mol% of a specific maleimide unit and 60-40 mol% of a specified olefin unit and having ≥1×10<SP>3</SP>to ≤5×10<SP>6</SP>number-average molecular weight and 99-1 wt.% of an amorphous nylon having ≤0.01 difference in refractive index from that of the maleimide-olefin copolymer at 589 nm measuring wavelength. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transparent film excellent in transparency, heat resistance, toughness 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 referred to as PMMA), polyester (hereinafter referred to as PET), polycarbonate (hereinafter referred to as PC), polyethersulfone (hereinafter referred to as PES), Films made from polyarylate (hereinafter referred to as PAR), norbornene resin, etc. are well known.

  On the other hand, it is disclosed that a film made of an N-substituted 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, a resin composition comprising an N-substituted maleimide / olefin copolymer and amorphous nylon has been proposed, and it is disclosed that it has characteristics such as excellent transparency, heat resistance, and mechanical strength. (For example, refer to Patent Document 3).

JP 09-328523 A

JP 2000-80240 A Japanese Patent No. 3208811

  However, the PMMA film has excellent optical properties and surface hardness, but has a problem of poor heat resistance and toughness, and the 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 cannot be used for optical applications where low birefringence is required. PC films, PES films, and PAR films are excellent in toughness and heat resistance, but are inferior in weather resistance and surface hardness and large in birefringence, and are not suitable for optical applications requiring low birefringence. The norbornene resin film has high heat resistance and low birefringence, but has a problem of poor adhesion.

  The film made of an N-substituted maleimide / olefin copolymer proposed in Patent Document 1 has characteristics such as high transparency and excellent heat resistance, but birefringence is not necessarily small enough to satisfy, and toughness Problems such as lack of

  Further, the film made of N-substituted maleimide / olefin copolymer and acrylonitrile / styrene copolymer described in Patent Document 2 has high transparency, excellent heat resistance, and extremely 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 amorphous nylon, and no examination has been made regarding a transparent film.

  As described above, the conventional transparent films have their own problems, and it is difficult to say that the demands for advanced and complicated processes in recent years should be satisfied. It 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 resin composition comprising an N-substituted maleimide / olefin copolymer or an N-substituted maleimide / olefin copolymer and an acrylonitrile / styrene copolymer, and a specific It has been found that a film made of amorphous nylon having a refractive index has high transparency, excellent heat resistance, surface hardness, rigidity, and toughness, and has completed the present invention.

That is, the present invention is a copolymer comprising 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 Amorphous nylon having 1 to 99% by weight of maleimide / olefin copolymer of not less than 10 ^{3 and not} more than 5 × 10 ⁶ and having a refractive index difference of 0.01 or less with respect to the maleimide / olefin copolymer at a measurement wavelength of 589 nm A transparent film comprising 99 to 1% by weight,

（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。）
と、
上記一般式（Ｉ）で示される単位４０〜６０モル％及び上記一般式（ＩＩ）で示される単位６０〜４０モル％からなる共重合体であり、数平均分子量が１×１０^３以上５×１０^６以下であるマレイミド・オレフィン共重合体５０〜９９重量％及びアクリロニトリル残基単位２１〜４５重量％を含むアクリロニトリル・スチレン共重合体５０〜１重量％からなる樹脂組成物（ａ）１〜９９重量％、測定波長５８９ｎｍにおける屈折率が該マレイミド・オレフィン共重合体の屈折率以上該アクリロニトリル・スチレン共重合体の屈折率未満の範囲にあり、該樹脂組成物（ａ）との屈折率差が０．０１以下である非晶性ナイロン９９〜１重量％からなることを特徴とする透明性フィルムに関するものである。

(R2 and R3 each independently represent hydrogen or an alkyl group having 1 to 6 carbon atoms.)
When,
It is a copolymer comprising 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), and the number average molecular weight is 1 × 10 ³ or more and 5 ×. A resin composition (a) 1 to 99 comprising 50 to 99% by weight of a maleimide / olefin copolymer of 10 ⁶ or less and 50 to 1% by weight of an acrylonitrile / styrene copolymer containing 21 to 45% by weight of an acrylonitrile residue unit. % By weight, the refractive index at a measurement wavelength of 589 nm is in the range of not less than the refractive index of the maleimide / olefin copolymer and less than the refractive index of the acrylonitrile / styrene copolymer, and there is a difference in refractive index from the resin composition (a). The present invention relates to a transparent film comprising 99 to 1% by weight of amorphous nylon which is 0.01 or less.

  Hereinafter, the present invention will be described in detail.

The first invention of the present invention is a copolymer comprising 40 to 60 mol% of the unit represented by the general formula (I) and 60 to 40 mol% of the unit represented by the following general formula (II), and has a number average 1 to 99% by weight of a maleimide / olefin copolymer having a molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less, and a refractive index difference from the maleimide / olefin copolymer at a measurement wavelength of 589 nm is 0.01 or less The present invention relates to a transparent film composed of 99 to 1% by weight of crystalline nylon.

The maleimide / olefin copolymer used in the present invention is a copolymer comprising 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). Yes, it has 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. In the case of a unit having an organic group other than these, the resulting film has poor heat resistance.

  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 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-dimethylphenyl group, , 6-diethylphenyl group, 2,6-di-n-propylphenyl group, 2,6-di-i-propylphenyl group, 2-methyl-6-ethylphenyl group, 2-methyl-6-i-propyl Phenyl group, 2,4,6-trimethylphenyl group, 2,4-dimethylphenyl group and the like can be mentioned, and since it is a transparent film particularly excellent in heat resistance, rigidity and toughness, it is represented by the general formula (I). R1 of the unit to be selected is preferably a methyl 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. When the number of carbon atoms exceeds 6, the resulting film has poor heat resistance. It will be a thing. 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 a maleimide / olefin copolymer is obtained, for example, by a radical copolymerization reaction between maleimides that derive a unit represented by the general formula (I) and olefins that derive a unit represented by the general formula (II). Can be obtained.

  At that time, examples of the compound for deriving the unit represented by the general formula (I) include N-methylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, and the like, and particularly, a transparent film excellent in heat resistance and rigidity. N-methylmaleimide is preferable because it is obtained.

  Examples of the compound for deriving the unit represented by the general formula (II) include olefins such as isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, 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 maleimide / olefin copolymer used in the present invention is in the range of 40 to 60 mol%, and in particular, it becomes a transparent film excellent in heat resistance and rigidity. It is preferable that it is 45-55 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 obtained film is lowered.

The maleimide / olefin copolymer used in the present invention has a number average molecular weight (Mn) of 1 × 10 ³ or more and 5 × 10 ⁶ or less, and becomes a transparent film particularly excellent in balance between toughness and molding processability. 1 × 10 ⁴ or more and 5 × 10 ⁵ or less are preferable. When the number average molecular weight exceeds 5 × 10 ⁶ , the melt viscosity of the maleimide / olefin copolymer becomes too high, resulting in poor fluidity and poor film thickness accuracy. 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 maleimide / olefin copolymer used in the present invention is particularly preferably an N-methylmaleimide / isobutene copolymer because it becomes a transparent film excellent in balance of heat resistance, toughness and rigidity.

  Furthermore, the maleimide / olefin copolymer used in the present invention may contain units derived from other monomer components as long as it does not impair the purpose of the present invention. Examples of 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 such as acrylic acid, methyl acrylate, and ethyl acrylate. Acids 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; one or more compounds selected from acrylonitrile And its content rate Preferably is not more than 5 mol%.

  The maleimide / olefin copolymer used in the present invention is obtained by polymerizing a compound derived from the unit represented by the general formula (I) and a compound derived from the unit represented by the general formula (II) by a known method. be able to. 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 preferably 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.

  The polymerization temperature at that time can be appropriately set according to the decomposition temperature of the initiator, but in general, it is preferably carried out in the range of 40 to 150 ° C.

  Alternatively, the maleimide / olefin copolymer can also be obtained by post-imidizing the maleic anhydride / olefin copolymer with an amine compound.

  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; An amine compound and a mixed solvent of an aromatic solvent and an alcohol solvent, dissolved or dispersed in a solvent such as N-methyl-2-pyrrolidone (hereinafter referred to as NMP), dimethylformamide (hereinafter referred to as DMF) A method in which an amidation reaction and an imidation reaction are continuously performed by reaction at a temperature of 50 to 250 ° C., an amide body is obtained by reacting with an amine compound, and then the amide body is heated to dehydrate and cyclize to form an imide It can manufacture by the method etc. which perform crystallization.

  Examples of amine compounds include, for example, methylamine, cyclopropylamine, cyclobutylamine, cyclohexylamine, adamantylamine, aniline, 2-methylphenylamine, 2-ethylphenylamine, 2-n-propylphenylamine, 2-i- Propylphenylamine, 2-n-butylphenylamine, 2-s-butylphenylamine, 2-t-butylphenylamine, 2-n-pentylphenylamine, 2-t-pentylphenylamine, 2,6-dimethylphenyl Amine, 2,6-diethylphenylamine, 2,6-di-n-propylphenylamine, 2,6-di-i-propylphenylamine, 2-methyl-6-ethylphenylamine, 2-methyl-6- i-propylphenylamine, 2,4,6-trimethylphenyl Min, 2,4-dimethylphenylamine, ethylamine, n-propylamine, n-butylamine, n-pentylamine, n-hexylamine, i-propylamine, i-butylamine, s-butylamine, t-butylamine, 1, 2-dimethylpropylamine and the like can be mentioned, and among them, since it becomes a transparent film having an excellent balance of heat resistance, toughness and rigidity, methylamine is used as an amine compound for deriving the unit represented by the general formula (I). Is preferred.

  The amorphous nylon used in the present invention preferably contains diamine and aromatic dicarboxylic acid as essential components, and further contains other aliphatic copolymer components. Representative examples of diamines include tetramethylene diamine, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, and 5-methylnona. Linear and branched aliphatic diamines having 2 to 18 carbon atoms, such as methylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane; 1,3-diamino Cyclohexane, 1,4-diaminocyclohexane, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, isophoronediamine, piperazine, 2,5-dimethylpiperazine, bis (4-aminocyclohexyl) Methane, bis (4-a Nocyclohexyl) propane, 4,4'-diamino-3,3'-dimethylcyclohexylmethane, 4,4'-diamino-3,3'-dimethylcyclohexylpropane, 4,4'-diamino-3,3'-dimethyl -5,5'-dimethylcyclohexylmethane, 4,4'-diamino-3,3'-dimethyl-5,5'-dimethylcyclohexylpropane, bis (4-amino-3-methyl-5-ethylcyclohexyl) methane, Bis (4-amino-3-methyl-5-ethylcyclohexyl) propane, bis (4-amino-3,5-diethylcyclohexyl) methane, bis (4-amino-3,5-diethylcyclohexyl) propane, bis (4 -Amino-3-methyl-5-isopropylcyclohexyl) methane, bis (4-amino-3-methyl-5- Sopropylcyclohexyl) propane, bis (4-amino-3,5-diisopropylcyclohexyl) methane, bis (4-amino-3,5-diisopropylcyclohexyl) propane, bis (4-amino-3-ethylcyclohexyl) methane, bis (4-amino-3-ethylcyclohexyl) propane, bis (4-amino-3-isopropylcyclohexyl) methane, bis (4-amino-3-isopropylcyclohexyl) propane, α-α'-bis (4-aminocyclohexyl) -P-diisopropylbenzene, α-α'-bis (4-aminocyclohexyl) -m-diisopropylbenzene, α-α'-bis (4-aminocyclohexyl) -1,4-cyclohexane, α-α'-bis ( 4-aminocyclohexyl) -1,3-cyclohexane Those derived from an aliphatic alkylene diamine having a cyclohexane ring can be cited as preferred examples.

  Typical examples of the aromatic dicarboxylic acid include isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, and a mixture thereof. In particular, isophthalic acid or a mixture of isophthalic acid and terephthalic acid is preferably used. . Representative examples of other aliphatic copolymer components constituting the amorphous nylon include amino acids such as 6-aminocaproic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid, paraaminomethylbenzoic acid; ε-caprolactam And lactams having 4 to 12 carbon atoms such as ω-lauryl lactam; aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedioic acid.

  The transparent film of the present invention may be composed of two or more types of amorphous nylon and a maleimide / olefin copolymer. By using two or more kinds of amorphous nylon, it becomes possible to adjust the refractive index of the amorphous nylon side by the blending ratio of the amorphous nylon, and when adjusting the refractive index with the maleimide / olefin copolymer. This is preferable because fine adjustment is easy.

  The transparent film of the present invention exhibits high transparency because the difference between the refractive index of the maleimide / olefin copolymer and the refractive index of amorphous nylon is 0.01 or less. Further, when the refractive index difference is 0.005 or less, it is preferable because higher transparency can be obtained, and when the refractive index difference is 0.001 or less, it is particularly preferable because very high transparency can be obtained. If the difference in refractive index exceeds 0.01, the resulting film becomes white turbid due to the light scattering phenomenon, resulting in poor transparency, and further, the compatibility between the maleimide / olefin copolymer and amorphous nylon becomes poor, This is not preferable because the toughness decreases. The refractive index in the present invention is measured at a measurement wavelength of 589 nm.

The second invention of the present invention is a copolymer comprising 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), and has a number average. It consists of 50 to 99% by weight of a maleimide / olefin copolymer having a molecular weight of 1 × 10 ³ or more and 5 × 10 ⁶ or less and 50 to 1% by weight of an acrylonitrile / styrene copolymer containing 21 to 45% by weight of acrylonitrile residue units. Resin composition (a) 1 to 99% by weight, the refractive index at a measurement wavelength of 589 nm is in the range of the refractive index of the maleimide / olefin copolymer and less than the refractive index of the acrylonitrile / styrene copolymer, The present invention relates to a transparent film made of 99 to 1% by weight of amorphous nylon having a refractive index difference with respect to (a) of 0.01 or less.

  Here, since the transparent film of the present invention has effects such as reduction of birefringence, improvement of thickness accuracy and surface smoothness, maleimide / olefin copolymer 50 to 99% by weight and acrylonitrile / styrene copolymer 50 to 50%. A maleimide / olefin copolymer and an acrylonitrile / styrene copolymer constituting the resin composition (a) are preferably composed of 1% by weight of the resin composition (a) and amorphous nylon. The blending ratio is preferably 50 to 99% by weight of maleimide / olefin copolymer and 50 to 1% by weight of acrylonitrile / styrene copolymer, and is particularly excellent in balance of thickness accuracy, surface smoothness and heat resistance, Maleimide / olefin copolymer 50-90% by weight, acrylonitrile because it becomes a transparent film with low birefringence It is preferred styrene copolymer 50-10 by weight.

  As the maleimide / olefin copolymer constituting the resin composition (a) used in the present invention, the maleimide / olefin copolymer described above can be used.

  The acrylonitrile / styrene copolymer constituting the resin composition (a) is a transparent film having excellent compatibility with the maleimide / olefin copolymer and excellent heat resistance. Therefore, the acrylonitrile residue unit 21 An acrylonitrile / styrene copolymer containing ˜45% by weight is preferred. Such an acrylonitrile / styrene copolymer can be obtained as a commercial product. The reason why the birefringence is reduced by blending the acrylonitrile / styrene copolymer in the transparent film of the present invention is that the maleimide / olefin copolymer exhibits positive birefringence, whereas acrylonitrile / styrene. Since the copolymer exhibits negative birefringence, the birefringence cancels out each other.

  As the amorphous nylon, the above-described amorphous nylon can be used. Even in that case, the refractive index of the amorphous nylon side can be adjusted by the blending ratio of the amorphous nylon, and fine adjustment when adjusting the refractive index with the resin composition (a) is facilitated. Two or more types of amorphous nylon are preferable.

  When the transparent film of the present invention is a transparent film comprising a resin composition (a) comprising a maleimide / olefin copolymer and an acrylonitrile / styrene copolymer, the resin composition (a), amorphous nylon, The blending ratio is preferably 1 to 99% by weight of the resin composition (a) and 99 to 1% by weight of amorphous nylon, and since it becomes a transparent film having an excellent balance of toughness and rigidity, the resin composition The product (a) preferably comprises 90 to 50% by weight and amorphous nylon 10 to 50% by weight.

  When an acrylonitrile / styrene copolymer is used, the refractive index of the resin composition can be adjusted by adjusting the blending ratio of the maleimide / olefin copolymer and the acrylonitrile / styrene copolymer. The reason why the refractive index can be adjusted by adjusting the blending ratio is that maleimide / olefin copolymer having a specific molecular structure and acrylonitrile / styrene copolymer are completely compatible with each other in molecular units. This is because the refractive index of the resin composition (a) comprising the coalescence and acrylonitrile / styrene copolymer can be changed by the blending ratio of both resins. In addition, since the range of the refractive index change is from the refractive index of maleimide / olefin copolymer to the refractive index of acrylonitrile / styrene copolymer, the refractive index of amorphous nylon at a measurement wavelength of 589 nm is expressed as the maleimide. The refractive index of the resin composition (a) comprising a maleimide / olefin copolymer and an acrylonitrile / styrene copolymer and having a refractive index greater than or equal to the refractive index of the olefin copolymer and less than that of the acrylonitrile / styrene copolymer. When the difference between the refractive index of amorphous nylon and the refractive index of the amorphous nylon is 0.01 or less, a film having excellent transparency can be obtained.

  The transparent film of the present invention contains phenol, phosphorus, sulfur, and other antioxidants as necessary in order to suppress coloring, decomposition, cross-linking, etc. caused by heat history such as molding. May be. 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-tert-butyl-6- (1- (3,5-di-tert-butyl-2-hydroxyphenyl) ethyl) phenyl acrylate, and 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 sulfur antioxidants include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thiodipropioate. And pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro (5,5) undecane and the like. It is done.

  Further, as other antioxidants, for example, as an antioxidant having both a function as a phenolic antioxidant and a function as a phosphorus antioxidant, 6- (3- (3 -T-butyl-4-hydroxy-5-methyl) propoxy) -2,4,8,10-tetra-t-butyldibenz (d, f) (1,3,2) -dioxaphosphine, vitamin E Examples of the system antioxidant include 3,4-dihydro-2,5,7,8-tetramethyl-2- (4,8,12-trimethyltridecyl) -2H-benzopyran-6-ol.

  Among the above antioxidants, it is preferable to contain a phenol-based antioxidant and a phosphorus-based antioxidant because the transparent film is 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 material, 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 or light deterioration occurs. Therefore, a hindered amine light stabilizer, an ultraviolet absorber, a light stabilizer, a near infrared absorber, and the like may be contained as necessary for the purpose of suppressing the thermal coloring and light deterioration. 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 as disclosed in JP 2001-98163 A, 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′-di-t -Salicylate derivatives such as butyl-4'-hydroxybenzoate and mixtures thereof, 2,4-dihydroxyben Zophenone, 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) benzo Triazole, 2- (3-tert-butyl-2-hydroxy-5-methyl Enyl) -5-chlorobenzotriazole, 2- (3′-s-butyl-2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octyloxyphenyl) Benzotriazole, 2- (3 ′, 5′-di-t-amyl-2′-hydroxyphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl) 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-chlorobenzotriazol 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-tetrahydrophthalimide) Methyl) -5-methylphenyl) benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chloroben Triazole, 2- (3′-dodecyl-2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (3′-t-butyl-2′-hydroxy-5 ′-(2-isooctyloxycarbonylethyl) ) Phenyl) benzotriazole mixture, 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'-hydroxy-) Condensates with 5 ′-(2-methoxycarbonylethyl) phenyl) benzotriazole, poly (3-11) (ethylene glycol) and methyl 3- (3- 2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl) propionate condensate, 2-ethylhexyl 3- (3-tert-butyl-5- (5-chloro-2H-benzotriazole) -2-yl) -4-hydroxyphenyl) propionate, octyl 3- (3-tert-butyl-5- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl) propionate, methyl 3- (3-t-butyl-5- (5-chloro-2H-benzotriazol-2-yl) -4-hydroxyphenyl) propionate, 3- (3-t-butyl-5- (5-chloro-2H-benzo) Triazol-2-yl) -4-hydroxyphenyl) propionic acid, and 2- (4,6-diphenyl-1,3,5-triazine-2- Yl) -5- (hexyl (oxy))-phenol and the like.

  Examples of near infrared absorbers include cyanine-based near infrared absorbers, pyrylium-based infrared absorbers, squarylium-based near-infrared absorbers; croconium-based infrared absorbers, azulenium-based near infrared absorbers, phthalocyanine-based near infrared absorbers, dithiol metals Examples thereof include complex near infrared absorbers, naphthoquinone near infrared absorbers, anthraquinone near infrared absorbers, indophenol near infrared absorbers, and azimuth near infrared absorbers.

  In addition to the above-mentioned components, the transparent film of the present invention includes pigments, lubricants, antiblocking agents, antistatic agents, surfactants, polymer electrolytes, conductive complexes, inorganic fillers, dyes, plasticizers, oils, etc. May be contained as necessary, and other resins may be contained only when transparency is not impaired. Although the detail is shown below, this invention is not restrict | limited to these at all.

  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-based lubricants; silicone oils, and the content of the lubricant is preferably 1 to 10,000 ppm.

  Other resins include impact-resistant resins including acrylonitrile / styrene copolymers, such as ASA (acrylonitrile / styrene / acrylic rubber), ABS (acrylonitrile / butadiene / styrene), AES (acrylonitrile / EPDM or EPR / styrene). ), SAS (styrene / acrylonitrile / silicon) and the like.

  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, diethyl ether, etc. For example, a drum-type casting machine, a band-type casting machine, or a spin coater can be used. Examples of the melt extrusion method include a T-die method and an inflation method. Further, the obtained film may be made into a transparent stretched film by a stretching method, and as a stretching method that can be adopted, for example, a tenter method, a tube method; a uniaxial stretching method, for example, a water tank stretching method, a radiation stretching method, etc. Method, hot air heating method, hot plate heating method, roll heating method and the like.

  The thickness of the transparent film of the present invention is preferably 10 to 500 μm, and it is particularly preferably 10 to 200 μm because it becomes a transparent film excellent in the balance of 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. In other words, 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 .; or a mixture of these resins Add inhibitors, waxes, dispersants, pigments, solvents, dyes, plasticizers, UV absorbers, inorganic fillers, gravure roll coating method, Meyer bar coating method, reverse roll coating method, dip coating method, air knife coating It can be applied by a method such as a coating method, a calender 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 formed by a plating method, a plasma CVD method or the like.

  It is also possible to laminate with other films. As a method of laminating, any publicly known method may be used. For example, heat bonding methods such as heat sealing method, impulse sealing method, ultrasonic bonding method, high frequency bonding method; extrusion laminating method, hot melt laminating method, Examples of the laminating method include 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, Examples thereof include an acetate resin film, a polyimide resin film, a polycarbonate resin film, and a polyacrylate resin film.

  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 rigidity, heat resistance, surface hardness, toughness and the like, it can be suitably used as an optical film. Examples of optical films include retardation films, polarizing film protective films, reflector films, separator films, and light diffusion films used in information equipment such as LCDs, organic ELs, PDPs, copiers, printers, facsimiles, touch panels, and optical files. Film: 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 bulb, cooking oven window, furnace sight window, selective transmission film surface heating element field: defroster , Aircraft, automobile, freezer, incubator, goggles, medical equipment, liquid crystal display device electronic parts / circuit materials field: capacitors, resistors, thin film composite circuits, leadless LSI chip carrier mounting, dry film resist electrode field: paper battery 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 reflective filter gas selective permeable 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 transparent film obtained by the present invention is excellent in heat resistance, rigidity, surface hardness, and toughness, 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 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.

~ 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.

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

~ Elongation at break ~
Measured according to ASTM D882.

~ Tensile modulus ~
Measured according to ASTM D882.

~ Birefringence ~
It measured on the conditions of measurement wavelength 546nm with the fully automatic birefringence meter (The Oji Scientific Instruments company make, brand name KOBRA-21ADH).

Synthesis Example 1 (Synthesis of N-methylmaleimide / isobutene copolymer)
In a 5 l separable flask equipped with a stirrer, a nitrogen introduction tube, a thermometer and a cooling tube, 500 g of maleic anhydride / isobutene copolymer (manufactured by Kuraray Co., Ltd., trade name Isoban 10) and N-methyl-2-2 as a solvent are used. 3000 g of pyrrolidone (hereinafter referred to as NMP) was charged and stirred at room temperature to dissolve the maleic anhydride / isobutene copolymer in NMP. Next, 200 g of methylamine gas was introduced at room temperature, and then 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, an imidization reaction was performed, and then the mixture was cooled to room temperature and reprecipitated using isopropanol to recover the polymer.

From the elemental analysis, infrared absorption spectrum measurement and ¹³ C-NMR measurement, it was confirmed that the ratio of N-methylmaleimide residue and isobutene residue in the produced polymer was 0.5 / 0.5 (molar ratio). did. Moreover, the number average molecular weight of the produced | generated polymer was 90000, and the refractive index was 1.5276.

Example 1
70% by weight of the N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 and 30% by weight of amorphous nylon (trade name Grillamide TR55LX; refractive index 1.5241 manufactured by EMS Showa Denko Co., Ltd.) were dry blended. Then, it was subjected to a biaxial extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) and extruded to obtain a resin composition. Subsequently, the obtained resin composition was subjected to a twin-screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) equipped with a T die, and extruded under conditions of a T die part temperature of 275 ° C and a cooling roll of 120 ° C. Thus, a transparent film having a thickness of 100 μm was obtained.

  Table 1 shows the results of physical properties measured using this transparent film. The obtained transparent film had high transparency and was excellent in the balance of rigidity, surface hardness, and toughness.

Example 2
85% by weight of the N-methylmaleimide / isobutene copolymer obtained by Synthesis Example 1 and acrylonitrile / styrene copolymer (trade name Sunrex SAN-L manufactured by Technopolymer Co., Ltd .; 29% by weight of acrylonitrile residue unit, Refractive index 1.5643) After dry blending 15% by weight, it was extruded through a twin-screw extruder (trade name Lab Plast Mill, manufactured by Toyo Seiki Seisakusyo Co., Ltd.), and resin composition (1) (refractive index 1.5331) )

  Next, 70% by weight of the obtained resin composition (1) and 30% by weight of amorphous nylon (produced by EMS Showa Denko Co., Ltd., trade name Grillamide TR55; refractive index 1.5336) were twin-screw extruder (Toyo Corporation) Extruded to Seiki Seisakusho, trade name Laboplast Mill) to obtain a resin composition. Subsequently, the obtained resin composition was subjected to a twin-screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) equipped with a T die, and extruded under conditions of a T die part temperature of 275 ° C and a cooling roll of 120 ° C. Thus, a transparent film having a thickness of 100 μm was obtained.

  Table 1 shows the results of physical properties measured using this transparent film. The obtained transparent film had high transparency, very low birefringence, and had an excellent balance of rigidity, surface hardness, and toughness.

Example 3
Amorphous nylon (Mus Showa Denko, trade name Grillamide TR55; refractive index 1.5336) 79% by weight and amorphous nylon (Mus Showa Denko, trade name Grillamide TR90; refractive index 1.5046) After dry blending 21% by weight, it was extruded through a twin-screw extruder (trade name: Laboplast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) to obtain an amorphous nylon composition (2) (refractive index 1.5299). It was.

  Next, 30% by weight of the obtained amorphous nylon composition (2) and 70% by weight of the N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 were mixed into a twin-screw extruder (manufactured by Toyo Seiki Seisakusho, The resin composition was obtained by extruding the product under the trade name Laboplast Mill). Subsequently, the obtained resin composition was subjected to a twin screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) equipped with a T die, and extruded under the conditions of a T die part temperature of 280 ° C and a cooling roll of 130 ° C. Thus, a transparent film having a thickness of 100 μm was obtained.

  Table 1 shows the results of physical properties measured using this transparent film. The obtained transparent film had high transparency and was excellent in the balance of rigidity, surface hardness, and toughness.

Comparative Example 1
The N-methylmaleimide / isobutene copolymer obtained in Synthesis Example 1 was subjected to a twin screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) equipped with a T die, and the T die part temperature was 285 ° C. A film having a thickness of 100 μm was obtained by extrusion under a cooling roll at 140 ° C.

  The results of measuring physical properties using this film are shown in Table 1. The obtained film had poor toughness.

Comparative Example 2
After dry blending 70% by weight of N-methylmaleimide / isobutene copolymer and 30% by weight of amorphous nylon (produced by EMS Showa Denko Co., Ltd., trade name Grillamide TR90; refractive index 1.5046), a twin screw extruder ( Extrusion was carried out using Toyo Seiki Seisakusho Co., Ltd. (trade name: Labo Plast Mill) to obtain a resin composition (3).

  Next, the obtained resin composition (3) was subjected to a twin screw extruder (trade name Lab Plast Mill, manufactured by Toyo Seiki Co., Ltd.) equipped with a T die, and the T die part temperature was 280 ° C and the cooling roll was 120 ° C. The film was extruded under conditions to obtain a film having a thickness of 100 μm.

  The results of measuring physical properties using this film are shown in Table 1. The obtained film was poor in transparency.

Comparative Example 3
In the same manner as in Example 2, a resin composition (1) composed of an N-methylmaleimide / isobutene copolymer and an acrylonitrile / styrene copolymer was obtained.

  Next, the obtained resin composition (1) was subjected to a twin-screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Co., Ltd.) equipped with a T die, and the T die part temperature was 275 ° C and the cooling roll was 120 ° C. The film was extruded under conditions to obtain a film having a thickness of 100 μm.

  The results of measuring physical properties using this film are shown in Table 1. The obtained film had poor toughness.

Comparative Example 4
A commercially available polycarbonate resin (manufactured by Teijin Kasei Co., Ltd., trade name L-1250ZW) is subjected to a twin-screw extruder (trade name: Labo Plast Mill, manufactured by Toyo Seiki Seisakusho Co., Ltd.) equipped with a T die, and the T die part temperature is 290 ° C. The film was extruded under the condition of a cooling roll of 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 1. The obtained film was poor in rigidity and surface hardness and had a large birefringence.

Claims (3)

It is a copolymer comprising 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 ×. 10 ⁶ or less is maleimide-olefin copolymer 1-99 weight%, from amorphous nylon 99-1 wt% refractive index difference is 0.01 or less and said maleimide-olefin copolymer at a measurement wavelength of 589nm A transparent film characterized by comprising:

(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.) It is a copolymer comprising 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 ×. A resin composition (a) 1 to 99 comprising 50 to 99% by weight of a maleimide / olefin copolymer of 10 ⁶ or less and 50 to 1% by weight of an acrylonitrile / styrene copolymer containing 21 to 45% by weight of an acrylonitrile residue unit. % By weight, the refractive index at a measurement wavelength of 589 nm is in the range of not less than the refractive index of the maleimide / olefin copolymer and less than the refractive index of the acrylonitrile / styrene copolymer, and there is a difference in refractive index from the resin composition (a). A transparent film comprising 99 to 1% by weight of amorphous nylon which is 0.01 or less.

(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.) The transparent film according to claim 1, wherein at least two kinds of amorphous nylon are used.