JP5919816B2 - Optical film - Google Patents

Description

  The present invention relates to an optical film having a low surface resistance made of a fumaric acid diester resin.

  In recent years, many plastic film materials are used as optical films for liquid crystal displays (hereinafter referred to as LCDs), organic EL displays, plasma display panels, electronic paper, touch panels, and the like. In particular, an optical film using a fumaric acid diester resin is useful because it can be used for a wide range of optical films by manipulating its transparency, heat resistance, birefringence and the like.

  However, fumaric acid diester resin having high heat resistance is very easy to be charged. Dust generation due to static electricity in film forming and drying processes by solution coating, and secondary processing processes such as cutting and laminating the produced optical film. There is a problem that adsorption or static electricity discharge phenomenon or handling deterioration due to sticking occurs.

  For this reason, when handling film materials, it is necessary to prevent contact with high-speed contact with metal rolls and other production equipment so that static electricity is difficult to generate, and to suppress friction as much as possible. Countermeasures against static electricity can also be made by adjusting the environment to a high level, using a water mist atmosphere, or using a static elimination device such as a static elimination bar or ionizer.

  On the other hand, on the material side of the optical film, countermeasures against static electricity are sometimes taken by adding an additive that lowers the surface resistance of the antistatic agent.

In general, non-ionic surfactants, cationic surfactants, anionic surfactants, etc. are added as antistatic agents to polymers that are easily charged with static electricity, and the surface resistance value is reduced. As a commercially available polymer material having a relatively low glass transition temperature, for example, it is widely used in olefin resins, acrylic resins, styrene resins, vinyl chloride resins, ester resins, urethane resins, and the like. However, it has a particularly high heat resistance such as a fumaric acid diester resin and does not show a glass transition temperature, or as a non-crystalline resin, a dynamic temperature at a temperature of 200 ° C. and a frequency of 10 Hz, for example. When the dynamic storage elastic modulus (E ′) obtained from the elasticity measurement is 2.0 × 10 ⁷ Pa or higher, the polymer has an antistatic agent and the like to reduce the surface resistance. Little is known about how to make it happen.

  However, as a study in terms of materials, for example, Patent Document 1 and Patent Document 2 describe a manufacturing method for producing an optical film and a coated thin film, but there is no description about charging characteristics and suppression of static electricity, and particularly a polymer. There is no description regarding a method for suppressing static electricity by blending an antistatic agent or the like into the film or film.

JP 2006-249318 A JP 2008-120551 A

  An object of the present invention is to provide an optical film using a fumaric acid diester resin, which has improved surface adsorption and improved dust adsorption, discharge, and handling properties due to electrostatic charging, and a method for producing the optical film. It is in.

As a result of intensive studies to solve the above problems, the present inventors have reduced the surface resistance of an optical film using a specific fumaric acid diester resin, and are less likely to cause problems caused by electrostatic charging. I found it. That is, the present invention relates to 100 parts by weight of a fumaric acid diester resin containing a fumaric acid diester residue represented by a predetermined general formula, or 75 mol% of a fumaric acid diester residue represented by a predetermined general formula. A fumaric acid diester resin containing a fumaric acid diester residue unit of more than less than 100 mol% and a (meth) acrylic acid ester residue having a cyclic ether group having 3 to 6 ring members exceeding 0 mol% and not more than 25 mol% It contains 0.3 to 3 parts by weight of a cationic surfactant or an anionic surfactant with respect to 100 parts by weight, and the surface resistance is 10 ¹⁴ Ω / □ or less at an applied voltage of 100 V as a surface resistance value. It is the optical film characterized.

  The present invention is described in detail below.

  In the optical film of the present invention, a cationic surfactant or an anionic surfactant is added in an amount of 0.001 part to 100 parts by weight of a fumaric acid diester resin containing a fumaric acid diester residue represented by the following general formula (1). It contains 3 to 3 parts by weight.

（式中、Ｒ_１及びＲ_２はそれぞれ独立して炭素数１〜１２である直鎖状若しくは分岐状アルキル基、又は炭素数３〜６である環状アルキル基を示す。）
また、本発明の光学フィルムは、上記一般式（１）で表されるフマル酸ジエステル残基７５モル％以上１００モル％未満、及び環員数３〜６の環状エーテル基を有する（メタ）アクリル酸エステル残基０モル％を超えて２５モル％以下のフマル酸ジエステル残基単位を含むフマル酸ジエステル系樹脂１００重量部に対して、カチオン系界面活性剤又はアニオン系界面活性剤を０．３〜３重量部含有するものである。

(In the formula, R ₁ and R ₂ each independently represent a linear or branched alkyl group having 1 to 12 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms.)
The optical film of the present invention is a (meth) acrylic acid having a fumaric acid diester residue represented by the general formula (1) of 75 mol% or more and less than 100 mol% and a cyclic ether group having 3 to 6 ring members. A cationic surfactant or an anionic surfactant is added in an amount of 0.3 to 100 parts by weight of a fumaric acid diester resin containing a fumaric acid diester residue unit exceeding 0 mol% and not more than 25 mol%. It contains 3 parts by weight.

  Here, as the fumaric acid diester resin, those containing a fumaric acid diester residue represented by the general formula (1) or 75 mol% or more and 100 mol of the fumaric acid diester residue represented by the general formula (1) are used. %, And a (meth) acrylic acid ester residue having a cyclic ether group having 3 to 6 ring members exceeds 0 mol% and contains 25 mol% or less fumaric acid diester residue units.

  Examples of the fumaric acid diester residue represented by the general formula (1) include dimethyl fumarate residue, diethyl fumarate residue, diisopropyl fumarate residue, di-tert-butyl fumarate residue, dimer fumarate. -N-butyl residue, di-sec-butyl fumarate residue, isobutyl fumarate residue, dipentyl fumarate residue, diisopentyl fumarate residue, di-sec-isoamyl fumarate residue, dineopentyl fumarate residue , Di-tert-pentyl fumarate residue, di-2-ethylhexyl fumarate residue, dicyclopropyl fumarate residue, dicyclobutyl fumarate residue, dicyclopentyl fumarate residue, dicyclohexyl fumarate residue Examples include at least one type of fumaric acid diester residue. The combination is not particularly limited, and for example, a combination in which many di-isopropyl fumarate residues and di-tert-butyl fumarate residues having a bulky molecular structure are blended is preferable.

  Examples of the (meth) acrylic acid ester residue having a cyclic ether group having 3 to 6 ring members contained in the fumaric acid diester resin include, for example, glycidyl acrylate residue, glycidyl methacrylate residue, acrylic acid- 3-ethyl-3-oxetanylmethyl residue, methacrylic acid-3-ethyl-3-oxetanylmethyl residue, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, 3,4-epoxycyclohexyl acrylate Examples thereof include (meth) acrylic acid ester residues having a cyclic ether having 3 to 6 ring members such as methyl residues and methacrylic acid-3,4-epoxycyclohexylmethyl residues. This is blended so that it exceeds 0 mol% and is 25 mol% or less as required when characteristics such as crosslinking are required.

  The fumaric acid diester resin may contain other monomer residue units as long as the effects of the present invention are exhibited. Examples of other monomer residue units include styrene residue units, α -Styrene residue units such as methylstyrene residue units; (meth) acrylic acid residue units; (meth) acrylic acid methyl residue units, (meth) ethyl acrylate residue units, (meth) acrylic acid butyl residues (Meth) acrylic acid ester residue units such as group units; vinyl ester residue units such as vinyl acetate residue units and vinyl propionate residue units; acrylonitrile residue units; methacrylonitrile residue units; methyl vinyl ether Residue units, vinyl ether residue units such as ethyl vinyl ether residue units, butyl vinyl ether residue units, etc .; N-methylmaleimide residue units, N-cyclohexylmale N-substituted maleimide residue units such as a mid residue unit and N-phenylmaleimide residue unit; Olefin residue units such as an ethylene residue unit and a propylene residue unit; Di-n-butyl fumarate residue unit 1 type, or 2 or more types selected from fumaric acid diester residue units other than the fumaric acid diester residue units such as bis (2-ethylhexyl) fumarate residue units.

  The fumaric acid diester resin preferably has a standard polystyrene equivalent number average molecular weight of 50,000 to 250,000 obtained from an elution curve measured by gel permeation chromatography (GPC).

  The fumarate diester resin may be produced by any method as long as the fumarate diester resin is obtained. For example, diisopropyl fumarate and a fumaric acid diester having an alkyl group having 1 or 2 carbon atoms may be used. It can be produced by performing radical polymerization or the like.

  For the radical polymerization, any known polymerization method such as bulk polymerization method, solution polymerization method, suspension polymerization method, precipitation polymerization method, emulsion polymerization method and the like can be adopted, but the polymerization can be performed by controlling the particle size. A suspension polymerization method that can be easily recovered is preferred.

  As a polymerization catalyst when performing radical polymerization, for example, benzoyl peroxide, lauryl peroxide, octanoyl peroxide, acetyl peroxide, di-t-butyl peroxide, t-butyl cumyl 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).

  And there is no restriction | limiting in particular as a solvent which can be used in solution polymerization method, suspension polymerization method, precipitation polymerization method, emulsion polymerization method etc., For example, aromatic solvents, such as benzene, toluene, xylene; Methanol, ethanol, propanol, butanol Examples include alcohol solvents such as cyclohexane, dioxane, tetrahydrofuran, acetone, methyl ethyl ketone, dimethylformamide, isopropyl acetate, and water, and a mixed solvent thereof can also be used.

  The polymerization temperature at the time of performing radical polymerization can be appropriately set according to the decomposition temperature of the polymerization initiator, and is generally preferably in the range of 30 to 150 ° C.

  When the cationic surfactant or anionic surfactant is less than 0.3 parts by weight relative to 100 parts by weight of the fumaric acid diester resin, the surface resistance is high and the antistatic performance is insufficient, and 3 parts by weight. If it exceeds 1, the amount added will be too large, causing problems such as bleeding on the surface and contamination.

  Examples of the cationic surfactant include a quaternary ammonium salt type surfactant. Examples of the quaternary ammonium salt type surfactant include lauryl trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride, distearyl dimethyl chloride. Ammonium, dioleyldimethylammonium chloride, alkylbenzyldimethylammonium chloride, ammonium alkylethylmethyl sulfate, alkylbis (2-hydroxyethyl) methylammonium chloride, polyoxyethylene alkylmethylammonium chloride, oleylbis (2-hydroxyethyl) methyl chloride Ammonium, methylbis (2-hydroxyethyl) cocoalkyl ammonium nitrate, methyl (2-hydroxyethyl) cocoalkylammonium chloride can be used, and one or more of those listed here and the like can be used, and those diluted with a solvent or the like can be used. .

  Examples of the anionic surfactant include a carboxylic acid type fatty acid salt having an arbitrary alkyl long chain, a sulfate type alkyl sulfonate, an alkyl benzene sulfonate, an alkyl sulfate, an alkyl ether sulfate, and a phosphate type. There are phosphoric acid esters and the like, and besides these, various acid salt type surfactants such as alkyl succinates can be mentioned.

  On the other hand, a nonionic surfactant is not effective even if it is added alone. Further, the fumaric acid diester resin of the present invention is amorphous and extremely heat-resistant, and when a film is formed only by blending a nonionic surfactant, as in a conventionally known polymer material, In the film handling after film formation, the surface resistance does not decrease and the effect cannot be obtained.

The optical film of the present invention has a surface resistance of 10 ¹⁴ Ω / □ or less at an applied voltage of 100 V as a surface resistance value. When the surface resistance exceeds 10 ¹⁴ Ω / □, the charging potential is high and handling is difficult. In order to obtain a better charging potential, the surface resistance is preferably 10 ⁹ to 10 ¹⁴ Ω / □.

In order for the optical film of the present invention to have higher heat resistance, the dynamic storage elastic modulus (E ′) obtained from dynamic viscoelasticity measurement at a temperature of 200 ° C. and a frequency of 10 Hz is 2.0 × 10 ⁷ Pa or more. It is preferable that

  The optical film of the present invention is excellent in transparency and preferably has a total light transmittance of 85% or more, particularly preferably 90% or more. Moreover, it is preferable that the light transmittance with respect to the light of wavelength 400nm is 80% or more. Furthermore, the haze is preferably 2% or less, particularly preferably 1% or less.

  The optical film of the present invention may contain an antioxidant, an ultraviolet stabilizer, and a light stabilizer in order to increase the thermal stability of the optical film itself during coating film formation. Antioxidants include, for example, hindered phenol antioxidants, phosphorus antioxidants, sulfur antioxidants, lactone antioxidants, amine antioxidants, hydroxylamine antioxidants, vitamin E series Antioxidants and other antioxidants may be mentioned, and these antioxidants may be used alone or in combination. Examples of UV stabilizers include benzotriazole UV stabilizers, benzophenone UV stabilizers, triazine UV stabilizers, and benzoate UV stabilizers. Examples of the light stabilizer include hindered amine light stabilizers.

  The optical film of the present invention may contain an ultraviolet absorber for the purpose of preventing deterioration of a liquid crystal compound or the like when used for, for example, a liquid crystal display film substrate. Examples include triazole ultraviolet absorbers, benzophenone ultraviolet absorbers, triazine ultraviolet absorbers, and benzoate ultraviolet absorbers.

  The optical film of the present invention may contain a plasticizer for the purpose of manipulating optical properties and mechanical properties. Examples of the plasticizer include a phthalate ester plasticizer, an adipate ester plasticizer, and a phosphate plasticizer. These plasticizers may be used alone or in combination.

  The optical film of the present invention contains additives such as other polymers, surfactants, polymer electrolytes, conductive complexes, inorganic fillers, antistatic agents, antiblocking agents, lubricants and the like within the scope of the invention. May be.

  As a manufacturing method of the optical film of this invention, it can form into a film by the solution cast method. The solution casting method is, for example, a method of forming an optical film by casting a dope solution prepared by dissolving a resin in a solvent on a supporting substrate and then removing the solvent by heating or the like. In that case, as a method of casting the dope solution on the support substrate, for example, a T-die method, a gravure roll method, a doctor blade method, a bar coat method, a roll coater method, a lip coater method, or the like can be used. In particular, industrially, the dope solution is extruded from a die onto a belt-like or drum-like support substrate and coated, and the gravure is used for scooping the dope solution onto an uneven pattern roll and transferring it to the support substrate side. The roll method is most commonly used.

  Examples of the supporting substrate used include polarized light such as TAC film, acrylic resin film, cyclic olefin film, PP film composed of a glass substrate, a triacetyl cellulose composition constituting a laminated polarizing plate, and the like. There are films and the like for the purpose of protecting the child and imparting a retardation, and the film is not limited to those mentioned here, and can be widely used as a supporting substrate for coating. Moreover, in order to obtain sufficient adhesive strength between the optical film of the present invention and the supporting substrate, adhesive treatment, substrate surface treatment, etc. may be applied, and known materials and techniques can be used.

  The coating thickness of the optical film at this time is preferably 10 to 150 μm in order to obtain a film having excellent coating appearance in the state after drying, high uniformity and low surface resistance.

  During film formation, the solvent used for dissolving the fumaric acid diester resin is a combination of a low-boiling solvent and a high-boiling solvent selected from solvents in which the resin is soluble, and the difference in boiling point of the solvent is 10 ° C. or more. The low boiling point solvent and the high boiling point solvent are used in a weight ratio of 5:95 to 95: 5, respectively.

  In this case, examples of the solvent include methyl ethyl ketone (boiling point: 80 ° C.), methyl isobutyl ketone (boiling point: 116 ° C.), cyclohexanone (boiling point: 156 ° C.), ethyl acetate (boiling point: 77 ° C.), and acetic acid butyl ester (boiling point). : 126 ° C), acetic acid isobutyl ester (boiling point: 117 ° C), cellosolve acetate (boiling point: 156 ° C), isopropyl alcohol (boiling point: 82 ° C), n-butyl alcohol (boiling point: 118 ° C), sec-butyl alcohol (boiling point) : 100 ° C), isobutyl alcohol (boiling point: 108 ° C), tetrahydrofuran (boiling point: 66 ° C), toluene (boiling point: 111 ° C), xylene (boiling point: 139 ° C), cellosolve (boiling point: 136 ° C), butyl cellosolve (boiling point: 170 ° C), methyl carbitol (boiling point: 194 ° C), ethyl Carbitol (boiling point: 202 ° C.), butyl carbitol (boiling point: 230 ° C.) and the like. Two types of these solvents can be used in combination. Here, as a combination of solvents, for example, isopropyl alcohol (boiling point: 82 ° C.) having a boiling point difference of 34 ° C. and methyl isobutyl ketone (boiling point: 116 ° C.) in a weight ratio of 5:95 to 95: 5, respectively. The ratio of methyl isobutyl ketone (boiling point: 116 ° C.) and xylene (boiling point: 139 ° C.) having a boiling point difference of 23 ° C. and a weight ratio of 5:95 to 95: 5 can be used respectively. Can be used in a range. In this way, by combining the low boiling point component and the high boiling point component in a weight ratio of 5:95 to 95: 5 by combining the solvent so that the boiling point temperature difference becomes 10 ° C. or more, the film after film formation can be obtained. Effective for lowering the surface resistance.

  On the other hand, when a low-boiling solvent or a high-boiling solvent is used as the sole solvent, the behavior of lowering the surface resistance of the film after film formation is not sufficient, which is not preferable. In particular, when a solution is prepared by using, for example, methyl ethyl ketone (boiling point: 80 ° C.) alone as a low boiling point solvent, the behavior of lowering the surface resistance of the film after film formation is not sufficient, and a high temperature exceeding 130 ° C. When a polymer solution is prepared using only a boiling point solvent and formed into a film, it is not preferable because nonuniform antistatic agent bleeding may occur on the back surface of the film.

  The resin solid content concentration when preparing the dope solution containing the fumaric acid diester resin and the solvent as described above is 5 to 30% by weight, and preferably 10 to 20% by weight. When the resin solid content exceeds 30% by weight, the viscosity becomes remarkably high and film formation becomes difficult. On the other hand, even when the resin solid content is less than 5% by weight, it is difficult to increase the thickness of the liquid film during film formation because the viscosity is low, and a film having a film thickness that can be handled as a thin film is obtained. It is not preferable because it is difficult.

  A known method can be used as a dope solution for preparing a solution by blending resin solids using a solvent as described above, and if it is a laboratory stirrer, a stirrer chip using a sample bottle or the like And a method of stirring using a device having a small motor type stirring blade such as a three-one motor, and as a mixer, for example, there are a batch type mixing method and a circulation type in-line mixing method, etc. Examples thereof include a propeller type, an axial flow turbine type, a radiation turbine type, an impeller type, a sawtooth blade type, a closed rotor type, and a rotor / stator type. It is necessary to adjust the dope solution in which the resin is dissolved in the solvent by such a method so that the undissolved material does not remain, and may be filtered through the filter for the purpose of removing foreign matters, dust, etc. Undissolved materials, foreign matters having a size of 3 μm or more, and dust can be removed by filtering the solution using an open 3 μm filter. A typical filter has a mesh size of about 0.5 to 20 μm and can be used in various combinations.

  The film formation by the solution casting method and the film thickness after drying are not particularly limited, but are preferably about 10 to 150 μm, and the drying condition at this time is that the relationship between the drying temperature and time is 40 to 80 ° C. on the low temperature side, respectively. After at least 2 to 5 minutes, it is dried at 90 to 130 ° C. for 5 minutes or more. After drying at 40 to 80 ° C. for less than 2 minutes as the low temperature side and then drying at 90 to 130 ° C. as the high temperature side, the surface resistance does not decrease, which is not preferable. On the other hand, it is possible to reduce the surface resistance even if it is further dried for a longer time on the low temperature side, but considering a practical film-forming process, it is preferable to dry at a shorter time, so that it is at least 2-5. About a minute is necessary.

  When the fumaric acid diester resin in the present invention contains a (meth) acrylic acid ester residue having a curable cyclic ether group having 3 to 6 ring members, it is crosslinked by electron beam, light and / or heat. It is a crosslinked film, and solvent resistance and dimensional stability during heating can also be improved by crosslinking.

  Here, it is preferable to use a crosslinking accelerator in order to uniformly and efficiently perform the crosslinking when crosslinking is performed and to obtain an optical film for display with good quality. Examples of the crosslinking accelerator include phenyl Aromatic diazonium salts such as diazonium hexafluoroantimonic acid, phenyldiasonium hexafluoric acid, phenyldiazonium tetrafluoroboric acid; diphenyliodonium hexafluoroantimonic acid, diphenyliodonium hexafluorophosphoric acid, diphenyliodoniumtrafluoroboric acid Aromatic sulfonium salts such as triphenylsulfonium hexafluoroantimonic acid, triphenylhexafluoric acid, triphenylsulfonium tetrafluoroboric acid; 1-benzyl-2-cyano Lithium hexafluoroantimonic acid, 1-benzyl-2-cyanopyridinium hexafluoric acid, aromatic ammonium salts such as 1-benzyl-2-cyanopyridinium tetrafluoroboric acid, ethyltriphenylphosphonium tetrafluoroantimonic acid, etc. Aromatic phosphonium salts: (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -iron complex; o-nitrobenzylsilyl ether-aluminum complex and the like. The addition amount of the crosslinking accelerator at that time is preferably 0.1 g to 10 g, particularly preferably 0.2 g to 5 g, with respect to 100 g of the fumaric acid diester resin.

  Examples of the method of crosslinking by heat include a method of simply heating, and examples of the method of crosslinking by light include a method using a mercury lamp, a metal halide lamp, an excimer lamp or the like as a light source. In addition, as a method of crosslinking with an electron beam, a commonly used electron beam irradiation apparatus can be used. In this crosslinking method using an electron beam, it is preferable to use a crosslinking aid such as a polyfunctional vinyl compound such as trimethylolpropane triacrylate and triallyl cyanurate in order to further increase the reaction efficiency. In the case of performing crosslinking with an electron beam, the irradiation intensity of the electron beam is preferably 5 to 500 kGy, and particularly preferably 10 to 100 kGy. The crosslinking by the electron beam is particularly suitable for crosslinking a fumaric acid diester resin having excellent heat resistance because of its excellent crosslinking efficiency, and the obtained optical film for display is particularly excellent in heat resistance.

  The optical film of the present invention can be used as an integrated polarizing plate laminate by directly coating and integrating a polarizing plate, or by laminating a pre-coated support substrate with a polarizing plate.

  The optical film of the present invention is also useful for polarizing plate protective films, retardation films, touch panels, flat panel display film substrates, liquid crystal display plastic substrates, liquid crystal display color filter substrates, organic EL display plastic substrates, and the like. .

  An object of the present invention is to provide an optical film using a fumaric acid diester resin as an optical film with reduced surface resistance and improved dust adsorption, discharge, and handling properties due to electrostatic charging. It is useful as a film production method.

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

  Hereafter, the method used for evaluation and measurement of an Example is shown.

<Measurement of number average molecular weight>
It measured using the gel permeation chromatography (GPC) apparatus (The Tosoh make, brand name: C0-8011), and computed as a standard polystyrene conversion value.

<Confirmation of composition of fumaric acid diester resin>
Using a nuclear magnetic resonance measuring apparatus (manufactured by JEOL Ltd., trade name: JNM-GX270), it was derived from proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR) spectrum analysis.

<Measurement of Dynamic Storage Elastic Modulus (E ′) of Film>
Using a viscoelasticity measuring device (DVE-V4, manufactured by Rheology), the dynamic storage elastic modulus of a film having a frequency of 10 Hz and a temperature of 200 ° C. is measured, and whether it is 2.0 × 10 ⁷ Pa or more and 200 It was judged whether it had heat resistance exceeding ° C.

<Measurement of light transmittance of optical film>
Based on JIS-K-7361-1, it measured with the haze meter (Nippon Denshoku Industries make, brand name: NDH5000).

<Measurement of birefringence and retardation of optical film>
Measurement was performed using a fully automatic birefringence meter (manufactured by Oji Scientific Instruments, trade name: KOBRA-21ADH).

  Here, the birefringence of the optical film refers to the refractive index in the two axial directions in the thin film plane with respect to the film forming direction, the reference axis as the slow axis nx, the fast axis ny orthogonal thereto, and the thin film thickness direction. When the axis is nz and the thickness of the thin film is d, it is expressed as the absolute value | nx−ny | The in-plane retardation (Re) of the thin film is (nx−ny) × d, the out-of-plane birefringence (ΔP) of the thin film is ((nx + ny) / 2−nz), and the out-of-plane retardation (Rth) of the thin film is (( nx + ny) / 2−nz) × d.

Synthesis Example 1 (Synthesis of fumaric acid diester resin (diisopropyl fumarate / diethyl fumarate copolymer))
Hydroxypropyl methylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: Metroles 60SH-50) 2 g, water 600 g, diisopropyl fumarate 365 g, diethyl fumarate 35 g, and polymerization start 3 g of t-butyl peroxypivalate was added as an agent, nitrogen bubbling was carried out for 1 hour, and then the suspension was kept at 45 ° C. for 24 hours while stirring at 400 rpm to carry out radical suspension polymerization. After cooling to room temperature, the resulting suspension containing the polymer particles was filtered, and washed with water and methanol to obtain a fumaric acid diester resin (diisopropyl fumarate / diethyl fumarate copolymer) (yield) : 65%).

The number average molecular weight of the obtained fumaric acid diester resin was 132,000, and the average particle diameter was 130 μm. ^Further, by 1 H-NMR measurement, the resin composition was diisopropyl fumarate residue units / diethyl fumarate residue units = 91/9 (mol%).

Synthesis Example 2 (Synthesis of fumaric acid diester resin (diisopropyl fumarate / diethyl fumarate copolymer))
Hydroxypropylmethylcellulose (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: Metrolose 60SH-50) 2 g, water 600 g, diisopropyl fumarate 330 g, diethyl fumarate 70 g and polymerization start in a 1 L autoclave equipped with a stirrer, a condenser, a nitrogen inlet tube and a thermometer 3 g of t-butyl peroxypivalate was added as an agent, nitrogen bubbling was performed for 1 hour, and then radical suspension polymerization was performed by maintaining at 45 ° C. for 36 hours while stirring at 400 rpm. After cooling to room temperature, the resulting suspension containing the polymer particles was filtered, and washed with water and methanol to obtain a fumaric acid diester resin (diisopropyl fumarate / diethyl fumarate copolymer) (yield) : 75%).

The number average molecular weight of the obtained fumaric acid diester resin was 120,000, and the average particle size was 110 μm. ^Further, by 1 H-NMR measurement, the resin composition was diethyl residue unit = 84/16 diisopropyl fumarate residue units / fumaric acid (mol%).

Synthesis Example 3 (Fumaric acid diester resin (synthesis of diisopropyl fumarate / acrylic acid-3-ethyl-3-oxetanylmethyl copolymer)
In a 0.5 L four-necked flask equipped with a stirrer, a condenser tube, a nitrogen inlet tube and a thermometer, 0.4 g of polyvinyl alcohol (molecular weight 2,000, saponification degree 80%), 260 g of distilled water, 122 g of diisopropyl fumarate (0 .609 mol), 18 g (0.106 mol) of methyl-3-ethyl-3-oxetanyl acrylate, and 0.8 g (0.005 mol) of tert-butyl peroxypivalate as a radical polymerization initiator were added, and nitrogen bubbling was performed. Was carried out for 1 hour, followed by radical polymerization by maintaining at 50 ° C. for 24 hours while stirring at 550 rpm. After completion of the polymerization reaction, the polymer in the flask was filtered off and washed with distilled water and methanol to obtain a fumaric acid diester resin (yield: 53%).

^{According to 1} H-NMR measurement, the obtained fumaric acid diester resin was diisopropyl fumarate residue / acrylic acid-3-ethyl-3-oxetanylmethyl residue = 86/14 (mol%). The number average molecular weight of the fumaric acid diester resin was 81,000, and the average particle size was 80 μm.

Synthesis Example 4 (Synthesis example of diisopropyl fumarate homopolymer resin)
A diisopropyl fumarate homopolymer resin was obtained in the same manner as in Synthesis Example 3 except that acrylic acid-3-ethyl-3-oxetanylmethyl was not used. The number average molecular weight of the obtained diisopropyl fumarate homopolymer resin was 81,500, and the average particle size was 100 μm.

Example 1
In a 250 cc container, 136 g of a mixed solvent (MIBK / xylene = 80/20 weight ratio) of methyl isobutyl ketone (MIBK) and xylene was stirred at a rotational speed of 1,400 rpm using TK-Robomix made by Primix. 24 g of the fumaric acid diester resin of Example 1 (diisopropyl fumarate residue unit / diethyl fumarate residue unit = 91/9 (mol%)) and Toho Chemical's Ansticks C-200 (quaternary ammonium salt type interface) Activator) 0.72 g (surfactant with respect to 100 parts by weight of fumaric acid diester resin: 3 parts by weight) was added for 1 minute from the start of stirring and stirred for 1 hour to prepare a dope solution.

Using this dope solution, coating was performed on a PET film by a solution casting method using a blade coater so that the film thickness after drying was 30 μm, dried at 40 ° C. for 2 minutes, and then at 90 ° C. The film was dried for 5 minutes and further dried at 130 ° C. for 5 minutes to produce a film (surfactant in the film: 3 parts by weight relative to 100 parts by weight of the fumaric acid diester resin). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91%, a haze of 0.4%, and a surface resistance as low as 9 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Comparative Example 1
A solution was prepared and formed in the same manner as in Example 1 except that a xylene single solvent was used as a solvent, and optical characteristics and surface resistance were measured. The obtained film had a total light transmittance of 90.5% and a haze of 0.5%, and the film surface peeled off from the PET film showed remarkable blurring and stickiness of an stick. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz. The film surface resistance at this time was as high as 1 × 10 ¹⁶ Ω / □ at an applied voltage of 100 V, and electrostatic charging was remarkable.
A solution was prepared and formed in the same manner as in Example 1 except that the MIBK solvent was used, and the optical properties and surface resistance were measured. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91%, a haze of 0.4%, and a surface resistance as low as 2 × 10 ¹² Ω / □ at an applied voltage of 100V.

Example 3
In Example 1, instead of the fumaric acid diester resin of Synthesis Example 1 (diisopropyl fumarate residue unit / diethyl fumarate residue unit = 91/9 (mol%)), the fumaric acid diester resin of Synthesis Example 2 (fumarate) The solution was the same except that diisopropyl residue / diethyl fumarate residue unit = 84/16 (mol%)) and a mixed solvent of MIBK and xylene (MIBK / xylene = 95/5 weight ratio) was used as a solvent. Preparation and film formation were performed, and optical properties and surface resistance were measured. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91% and a haze of 0.3%, and the film appearance was good. At this time, the film surface resistance was as low as 1 × 10 ¹¹ Ω / □ at an applied voltage of 100V.

Example 4
In Example 1, instead of the fumaric acid diester resin of Synthesis Example 1 (diisopropyl fumarate residue unit / diethyl fumarate residue unit = 91/9 (mol%)), the fumaric acid diester resin of the synthesis example 3 (fumarate Except that acid diisopropyl residue unit / acrylic acid-3-ethyl-3-oxetanylmethyl residue unit = 86/14 (mol%)) and 0.36 g of diphenyliodonium hexafluoric acid was added at the time of solution adjustment. A solution was prepared in the same manner, and the film was formed and dried. This film was irradiated with light with a mercury lamp for 10 minutes to perform crosslinking to obtain a crosslinked film. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 90.5%, the haze was 0.4%, and the film appearance was good. The film surface resistance at this time was as low as 7 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Comparative Example 2
A solution was prepared and formed in the same manner except that the drying temperature was only 10 minutes at 130 ° C. in Example 1, and the optical properties and surface resistance were measured. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 90.5%, the haze was 0.5%, and the film appearance was good. The film surface resistance at this time was as high as 1 × 10 ¹⁷ Ω / □ at an applied voltage of 100 V, and electrostatic charging was remarkable.

Example 5
In Example 1, instead of the fumaric acid diester resin of Synthesis Example 1 (diisopropyl fumarate residue unit / diethyl fumarate residue unit = 91/9 (mol%)), the fumaric acid diester resin of Example 4 (fumarate) A solution was prepared in the same manner except that the diisopropyl acid homopolymer resin was used, and the film was formed and dried. This film was irradiated with light with a mercury lamp for 10 minutes to perform crosslinking to obtain a crosslinked film. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 91%, the haze was 0.5%, and the film appearance was good. The film surface resistance at this time was as low as 7 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Example 6
A film was prepared and evaluated in the same manner as in Example 1, except that the film thickness was 150 μm. The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 91%, the haze was 0.5%, and the film appearance was good. The film surface resistance at this time was as low as 7 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Example 7
In Example 1, except that it was 0.36 g (surfactant with respect to 100 parts by weight of fumaric acid diester resin: 1.5 parts by weight) manufactured by Toho Chemical Co., Ltd. In the same manner, the film was prepared and evaluated from the preparation of the solution (surfactant in the film: 1.5 parts by weight with respect to 100 parts by weight of the fumaric acid diester resin). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 91%, the haze was 0.5%, and the film appearance was good. At this time, the film surface resistance was as low as 3 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Example 8
In Example 1, except that it was 0.072 g (surfactant with respect to 100 parts by weight of fumaric acid diester resin: 0.3 part by weight) manufactured by Toho Chemical Co., Ltd. In the same manner, from the preparation of the solution, the film was formed and evaluated (surfactant in the film: 0.3 part by weight relative to 100 parts by weight of the fumaric acid diester resin). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The total light transmittance of the obtained film was 91%, the haze was 0.5%, and the film appearance was good. The film surface resistance at this time was as low as 8 × 10 ¹³ Ω / □ at an applied voltage of 100V.

Comparative Example 3
The same as Example 1 except that 1.2 g (surfactant with respect to 100 parts by weight of fumaric acid diester resin: 5 parts by weight) manufactured by Toho Kagaku Ansticks C-200 (quaternary ammonium salt-based surfactant) was used. From the preparation of the solution, film formation and evaluation were carried out (surfactant in the film: 5 parts by weight relative to 100 parts by weight of the fumaric acid diester resin). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91% and a haze of 0.5%, and the film surface peeled off from the PET film showed remarkable blurring and stickiness of anstick. The film surface resistance at this time was as low as 2 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Example 9
In Example 1, in place of Tosu Chemicals Ansticks C-200 (a quaternary ammonium salt surfactant), Stacyside Conc (methylbis (2-hydroxyethyl) cocoalkyl ammonium nitrate and methylbis ( 2-hydroxyethyl) 60% by weight of cocoalkylammonium salt as a main component)) 0.4 g (surfactant with respect to 100 parts by weight of fumaric acid diester resin: 1 part by weight) From the preparation of the solution, film formation and evaluation were performed (surfactant in the film: 1 part by weight based on 100 parts by weight of the fumaric acid diester resin). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91.5% and a haze of 0.4%. The film surface resistance at this time was as low as 2 × 10 ¹⁰ Ω / □ at an applied voltage of 100V.

Example 10
In Example 1, 3.6 g (fumaric acid diester resin) of electrostripper ME-2 (polyoxyalkylene alkyl ether sulfate) instead of Toshou Chemicals Anstax C-200 (a quaternary ammonium salt surfactant) A solution was prepared, formed into a film, and evaluated in the same manner except that the surfactant was 100 parts by weight (1.5 parts by weight) (surfactant in the film: 100 parts by weight of the fumaric acid diester resin). 1.5 parts by weight). The obtained film had a dynamic storage elastic modulus (E ′) of 2.0 × 10 ⁷ Pa or more at 200 ° C. and a frequency of 10 Hz, and had heat resistance of 200 ° C. or more. The obtained film had a total light transmittance of 91% and a haze of 0.5%. At this time, the film surface resistance was as low as 3 × 10 ¹² Ω / □ at an applied voltage of 100V.

Example 11
In the film of Example 1, the in-plane retardation (Re) is 0 nm, the out-of-plane retardation (Rth) is 135 nm, and the refractive indices of the films are nx = 1.4685, ny = 1.4685, nz = The relationship was 1.4730, and the relationship was nz> nx = ny. Using this film as a polarizing plate protective film, an ethyl acetate solution of polyester polyol and isocyanate was applied to one side of the polarizing plate protective film using a bar coater, and bonded to both sides of the polyvinyl alcohol / iodine polarizing plate, 120 ° C. For 1 hour. The laminated film laminate was not peeled off by heating and could be used as a retardation compensation film and / or a polarizing plate protective film.

Example 12
It consists of the film of Example 3, and the film which does not deteriorate at 200 ° C. for 30 minutes as the oven heat resistance is room temperature, the background pressure is 1 * 10 ⁻⁷ torr, the sputtering gas pressure is 0.6 Pa (Ar: 80 SCCM, N2: 20 SCCM), and sputtering was performed under the condition of an RF magnetron of 500 W as an applied voltage, and a silicon nitride layer having a thickness of 100 nm was formed on both surfaces of the film. On this film, ITO sputtering treatment was performed at a temperature of 200 ° C., a background pressure of 1 * 10 ⁻⁷ torr, a sputtering gas pressure of 0.6 Pa (Ar: 80 SCCM, O ₂ : 20 SCCM), and an applied voltage of RF magnetron 500 w. An ITO film was formed. The formed barrier film and ITO film showed good adhesion and could be used as a touch panel film.

Example 13
It consisted of the film of Example 3, and was usable as a color filter substrate for a liquid crystal display because it was not deteriorated by holding at 200 ° C. for 30 minutes as an oven heat resistance.

Claims (1)

A retardation compensation film comprising a film laminate in which an optical film is bonded to both sides of a polarizing plate, wherein the optical film comprises a diisopropyl fumarate residue and an alkyl residue having 1 or 2 carbon atoms. relative to 100 parts by weight of the resin, a cationic surfactant or an anionic surfactant containing 0.3 to 3 parts by weight, the surface resistance at an applied voltage of 100V as a surface resistivity shows the 10 ¹⁴ Ω / □ or less a light optical film, the optical refractive index of the relationship of the film, each slow axis nx 2 one axial index of refraction of the film in the plane direction of film as a reference, the phase advance axis ny perpendicular thereto, the film A retardation compensation film having a relationship of nz> nx = ny, where nz is an axis in the thickness direction .