JP2008158515A - Method for producing optical film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an optical film having improved adhesion properties when two or more transparent resin layers are formed on one surface of a transparent resin film. <P>SOLUTION: In the method for producing the optical film by forming at least two transparent resin layers on a transparent resin film, the lower layer having a binder consisting mainly of a thermoplastic resin having a weight average molecular weight of 20,000-400,000 is applied and dried, the upper layer consisting mainly of an active ray-curing or thermosetting resin is applied thereon, and when the upper layer is dried, it is dried at a temperature higher than the glass transition point of the binder of the lower layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical film used for optical applications and a method for manufacturing the same, and particularly useful for manufacturing a protective film for a polarizing plate used for a display device such as a liquid crystal display device, an organic EL display, a plasma display, and the like. The present invention relates to a method for manufacturing an optical film. In particular, a method for producing a clear hard coat optical film excellent in smoothness is provided.

  In transparent resin films used for optical applications such as polarizing plate protective films for liquid crystal displays, circular polarizing plates used for organic EL displays, and elliptical polarizing plates, a transparent resin layer is used to provide various functions. It is painted.

  For example, an antistatic layer for providing an antistatic function, a hard coat layer for improving surface hardness, an undercoat layer for improving film adhesion, an anti-curl layer for preventing curling, etc. .

  When two or more such transparent resin layers are coated on the transparent resin film, the adhesion of each layer sometimes becomes a problem. In particular, there is a problem in a light resistance test by ultraviolet irradiation or the like, and the improvement has been demanded. Furthermore, in order to have various functions, fine particles may be added to the lower layer.

For example, when the lower layer is an antistatic layer, conductive fine particles are added. In that case, the adhesion between each layer and the adhesion between the added fine particles and the lower layer binder may be problematic.
Japanese Patent Laid-Open No. 2-27436

  Accordingly, an object of the present invention is useful as an optical film with improved adhesion of each layer, particularly as a protective film for a polarizing plate used in a display device, when two or more transparent resin layers are formed on one side on a transparent resin film. It is providing the optical film and its manufacturing method.

The above object of the present invention is achieved by the following configurations.
(1) In a method for producing an optical film in which at least two or more transparent resin layers are provided on a transparent resin film, a lower layer having a binder whose main component is a thermoplastic resin having a weight average molecular weight of 20,000 to 400,000 After coating and drying, after coating the upper layer mainly composed of actinic ray curable resin or thermosetting resin thereon, when drying the upper layer, the upper layer is heated at a temperature equal to or higher than the glass transition point of the lower layer binder. A method for producing an optical film, comprising drying.
(2) The method for producing an optical film as described in (1) above, wherein the transparent resin film is a cellulose ester film.
(3) The method for producing an optical film as described in (2), wherein the upper layer contains an ultraviolet curable polyol acrylate resin.

  According to the present invention, when two or more transparent resin layers are formed on one side on a transparent resin film, a method for producing an optical film with improved adhesion can be provided.

  Hereinafter, the present invention will be described in detail.

  When two or more transparent resin layers are provided on one side of the transparent resin film, there is a problem that the adhesion of the coating layer is deteriorated. As a part that deteriorates the adhesion, the adhesion between the lower layer and the upper layer, the adhesion between the lower layer and the transparent resin film as the support, and the adhesion between the lower layer binder and the particles when adding fine particles to the lower layer It became clear.

  Therefore, as a result of intensive studies to solve this problem, it has been found that the adhesion is improved by using a resin having a weight average molecular weight of 20,000 to 400,000 for the binder used in the lower layer.

  In particular, the resin used here is preferably a thermoplastic resin, and is coated in a state dissolved in a suitable solvent.

  Examples of the resin used here include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate phthalate, cellulose acetate propionate, and cellulose nitrate, polyvinyl acetate, polystyrene, polycarbonate, and polybutylene. Polyesters such as terephthalate, or copolybutylene-tere / isophthalate, polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polyvinyl alcohol derivatives such as polyvinyl benzal, norbornene-based polymers containing norbornene compounds, polymethyl methacrylate, etc. Acrylic resins such as copolymers containing methyl (meth) acrylate can be used. But it is not limited thereto.

  Among these, a cellulose derivative or an acrylic resin is preferable, and an acrylic resin is most preferably used. Further, a thermoplastic resin having a glass transition point of 110 ° C. or lower, more preferably 90 ° C. or lower is preferably used.

  The resin used here is preferably 60% by mass or more, more preferably 80% by mass or more of the whole binder used in the lower layer, and if necessary, actinic ray curable resin or thermosetting resin may be blended. it can.

  Another embodiment of the present invention also provides a method for improving adhesion when fine particles are added to the lower layer.

  That is, it became clear that the adhesion does not decrease even when fine particles are added by using a lower layer in which the ratio of the fine particles to the binder is 0.5 to 4 parts by mass with respect to 1 part by mass of the fine particles.

  In particular, it is preferable to use a thermoplastic resin having a weight average molecular weight of 20,000 to 400,000 as the binder, and a resin having a glass transition point of 90 ° C. or lower is preferably used.

  In another embodiment of the present invention, when the optical film is produced, after the lower layer is applied, when the upper layer is applied and dried, the upper layer is further dried at a temperature equal to or higher than the glass transition point of the lower layer binder. It has been found that the adhesion can be improved.

  In the present invention, the binder used in the upper layer is not particularly limited, but particularly when an actinic radiation curable resin or thermosetting resin is used, the glass transition of the lower layer binder is cured when the upper layer resin is cured or before curing. Adhesion was improved by setting the temperature to a point or higher.

  The present invention will be described more specifically below, but is not particularly limited thereto.

  The transparent resin film used in the present invention is not particularly limited. For example, polyester film, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate propionate film (CAP film), cellulose acetate butyrate film ( CAB film), film made of cellulose triacetate or cellulose derivative, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, norbornene resin film, polymethylpentene film, polyether ketone Film, polyethersulfone film, polysulfone film, An ether ketone imide film, a polyamide film, a fluororesin film, a nylon film, a polymethyl methacrylate film, an acrylic film, a polyarylate film, and the like can be mentioned. In the present invention, a cellulose triacetate film (hereinafter abbreviated as a TAC film). Cellulose acetate propionate film (CAP film), polycarbonate (hereinafter abbreviated as PC) film, syndiotactic polystyrene film, polyarylate film, norbornene resin film and polysulfone film are transparent. It is preferable because it has no mechanical properties and optical anisotropy. Especially, TAC film and PC film are easy to form and have excellent processability. Used preferred, especially when using the TAC film, a significant effect was observed.

  When the cellulose ester film is used, the cellulose ester film may be subjected to alkali saponification treatment before coating each coating layer of the present invention or may be subjected to alkali saponification treatment after coating.

  For example, after forming a film, it is possible to apply an antistatic layer and / or an ultraviolet curable resin layer or further an antireflection layer after an alkali saponification treatment, or to apply a backcoat layer, an antistatic layer, or an ultraviolet curable resin layer. After that, an alkali saponification treatment can be performed, and an antireflection layer (such as a low refractive index layer) can be further applied.

  Next, a method for forming a cellulose ester film will be described using TAC as an example. It can be similarly manufactured by using CAP or CAB instead of TAC.

  In general, a TAC film is obtained by dissolving a TAC flake raw material and a plasticizer in methylene chloride to form a viscous liquid, and dissolving the plasticizer into a dope. From an extruder screw, endless rotating stainless steel, etc. It is cast on a metal belt (also referred to as a band), dried, peeled off from the belt in a dry state, and dried from both sides by a roll or other conveying device and wound up. The PC film can be formed in the same manner as the TAC film.

  The wound TAC or PC film is coated with an antistatic coating solution composition or the like in the next coating step, but generally, it is wound up and coated again after each coating. Thus, the coating is performed intermittently.

  This method has the disadvantages that the yield is reduced, the transportation cost is high, and the film is easily damaged. The present inventors continuously apply various coating liquid compositions in one step, thereby increasing the yield, reducing the cost, and damaging the film. It was discovered that the adhesion between the coating layers was better and the continuous coating method was found to be preferable.

  In addition, so-called in-line coating (film formation and coating are in the same line) that connects the TAC or PC film deposition line and the coating line is better in terms of yield, cost, adhesion, etc. I found it.

  Therefore, as in the present invention, in order to perform various types of coating, the continuous coating method is preferable to the intermittent coating, and the in-line method is particularly preferable to the continuous method.

  As the plasticizer, phosphoric acid esters or carboxylic acid esters are preferably used. Phosphoric esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP), biphenyl-diphenyl phosphate, dimethyl ethyl phosphate. Representative carboxylic acid esters include phthalic acid esters and citric acid esters.

  Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diethyl hexyl phthalate (DEHP), ethyl phthalyl ethyl glycolate and the like. As the citrate ester, acetyl triethyl citrate (OACTE) and acetyl tributyl citrate (OACTB) are used.

  Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  Phosphate ester plasticizers (TPP, TCP, biphenyl-diphenyl phosphate, dimethylethyl phosphate) and phthalate ester plasticizers (DMP, DEP, DBP, DOP, DEHP) are preferably used.

  In addition, a polymer compound having a polymerization average molecular weight of 1,000 to 100,000, such as a polyvinyl acetate copolymer, an aliphatic linear polyester, and a methyl methacrylate copolymer, can be added as a polymer plasticizer.

  The plasticizer is an important material for imparting water resistance to the TAC film, but it is preferable to add as little as possible to the protective film for polarizing plate. The addition amount of the plasticizer is usually 2 to 10% by mass, preferably 4 to 8% by mass. The above plasticizer is generally unnecessary for the PC film, but it may be added.

  Moreover, the protective film for polarizing plates excellent in light resistance can be obtained by containing a ultraviolet absorber in the TAC film or PC film useful for this invention.

  Examples of ultraviolet absorbers useful in the present invention include salicylic acid derivatives (UV-1), benzophenone derivatives (UV-2), benzotriazole derivatives (UV-3), acrylonitrile derivatives (UV-4), benzoic acid derivatives (UV- 5) or an organic metal complex salt (UV-6), and (UV-1) is phenyl salicylate, 4-t-butylphenylsalicylic acid, etc., and (UV-2) is 2-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone and the like (UV-3) include 2- (2'-hydroxy-5'-methylphenyl) -benzotriazole, 2- (2'-hydroxy-3'-5 ' -Di-butylphenyl) -5-chlorobenzotriazole and the like (UV-4) is 2-ethylhexyl-2-cyano-3 3'-diphenyl acrylate, methyl-α-cyano-β- (p-methoxyphenyl) acrylate and the like (UV-5) include resorcinol-monobenzoate, 2 ', 4'-di-t-butylphenyl- 3,5-t-butyl-4-hydroxybenzoate and the like (UV-6) include nickel bis-octylphenylsulfamide, ethyl-3,5-di-t-butyl-4-hydroxybenzyl phosphate A nickel salt etc. can be mentioned.

  In addition, in order to improve the slipperiness, fine particles such as silica (average particle size of 0.005 to 0.2 μm) are added in an amount of 0.01 to 0.5% by mass in the dope when these base transparent films are produced. It can also be added.

  For example, Nippon Aerosil's Aerosil 200V, Aerosil R972V, etc. can be added. The sliding property is measured with a steel ball, and it is desired that the coefficient of dynamic friction is 0.4 or less, preferably 0.2 or less. The application of slipperiness can also be performed by an anti-blocking layer described later.

  The composition for forming a transparent resin layer of the present invention is used for coating a transparent resin layer for surface processing on an optical film. Examples of the surface processing include anti-blocking processing, anti-glare processing, anti-reflection processing, clear hard processing, anti-static processing, anti-curling processing, and easy adhesion processing.

  Here, the clear hard processing is to impart durability such as friction resistance and chemical resistance to the surface of the transparent resin film, and specifically, a method by providing an actinic radiation curable resin layer described later is preferable. As mentioned.

  The transparent resin layer on the optical film of the present invention is a layer mainly composed of a thermoplastic resin, a radiation curable resin, a thermosetting resin, and other resins.

  Examples of the optical film for forming two or more transparent resin layers on one side of the present invention include the following examples, but are not particularly limited thereto.

Clear hard layer (upper layer) / Antistatic layer (lower layer) / Transparent resin film / Anti-blocking layer Clear hard layer (upper layer) / Undercoat layer (lower layer) / Transparent resin film / Anti-blocking layer Clear hard layer / Transparent resin film / Antistatic layer (lower layer) / Easily adhesive layer (upper layer)
The present invention will be further described in the case where an antistatic layer is provided on a transparent resin film and a clear hard coat layer is provided thereon.

  Antistatic processing is to impart a function to prevent the resin film from being charged when handling a transparent resin film. Specifically, a layer containing an ion conductive substance or conductive fine particles is added. It is done by providing.

  Here, the ion conductive substance is a substance that shows electric conductivity and contains ions that are carriers for carrying electricity, and examples include ionic polymer compounds.

  Examples of the ionic polymer compound include anionic polymer compounds such as those described in JP-B-49-23828, JP-A-49-23827, and JP-A-47-28937, JP-B-55-734, and JP-A-50-54672. Ionene type polymer having a dissociating group in the main chain, as shown in JP-B-59-14735, JP-B-57-18175, JP-B-57-18176, and 57-56059, etc. No. 57-15376, No. 53-45231, No. 55-145783, No. 55-65950, No. 55-67746, No. 57-11342, No. 57-19735, No. 58-56858. No., JP-A 61-27853, 62-9346, and a cationic pendant type having a cationic dissociation group in the side chain And the like can be given Rimmer.

Examples of conductive fine particles include conductive metal oxides. As an example of the metal oxide, ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof is preferable. In particular, ZnO, TiO ₂ and SnO ₂ are preferred.

Examples of containing different atoms include, for example, addition of Al, In, etc. to ZnO, addition of Nb, Ta, etc. to TiO ₂ , and addition of Sb, Nb, halogen elements, etc. to SnO ₂ . Addition is effective. The amount of these different atoms added is preferably in the range of 0.01 mol% to 25 mol%, but is particularly preferably in the range of 0.1 mol% to 15 mol%.

The volume resistivity of these conductive metal oxide powders is 10 ⁷ Ωcm or less, particularly 10 ⁵ Ωcm or less, the primary particle diameter is 100 μm or more and 0.2 μm or less, and the major structure has a long diameter. It is preferable that the conductive layer contains a powder having a specific structure of 300 to 6 μm in a volume fraction of 0.01% to 20%.

  It is particularly preferable to contain an ionene conductive polymer described in JP-A-9-203810 or a quaternary ammonium cation conductive polymer having intermolecular crosslinking.

  The characteristic of the cross-linked cationic conductive polymer is the dispersible granular polymer obtained, and since it can have a high concentration and high density of the cationic component in the particles, it only has excellent conductivity. No deterioration of conductivity was observed even under low relative humidity, and although the particles were well dispersed in the dispersed state, the adhesion of the particles was good in the film-forming process after coating, so the film strength was also low. It is strong and has excellent adhesion to other substances such as supports, and has excellent chemical resistance.

  The dispersible granular polymer, which is a crosslinked cationic conductive polymer used in the antistatic layer, is generally in the particle size range of about 0.01 μm to 0.5 μm, preferably in the range of 0.05 μm to 0.08 μm. Size is used.

  As used herein, the term dispersible particulate polymer is a polymer that appears as a clear or slightly turbid solution by visual observation but appears as a granular dispersion under an electron microscope. By using a coating composition that does not substantially contain dust (foreign matter) larger than the particle diameter corresponding to the film thickness of the upper layer in the lower layer coating composition, failure of foreign matter in the upper layer can be prevented.

  The ratio of the fine particles to the binder is preferably 0.5 to 4 parts by mass of the binder with respect to 1 part by mass of the fine particles, and particularly the adhesiveness after UV irradiation is such that the binder is contained with respect to 1 part by mass of the fine particles. It is preferable that it is 1-2 mass parts.

  As the transparent resin binder used for the antistatic layer, a resin having a weight average molecular weight of 20,000 to 400,000 can be preferably used.

  In particular, the resin used here is preferably a thermoplastic resin, and a resin having a glass transition point of 110 ° C. or lower, more preferably 90 ° C. or lower is used.

  Examples of the resin used herein include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate, cellulose acetate phthalate, and cellulose nitrate, polyvinyl acetate, polystyrene, polycarbonate, and polybutylene. Polyesters such as terephthalate or copolybutylene-tere / isophthalate, polyvinyl alcohols such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, or polyvinyl benzal, norbornene polymers containing norbornene compounds, polymethyl methacrylate, polyethyl Methacrylate, polypropyltyl methacrylate, polybutyl methacrylate Acrylic resin such as poly (meth) acrylate such as polymethyl acrylate, methyl methacrylate and methyl acrylate copolymer, or a copolymer of acrylic resin and other resin can be used, but is not limited to these. It is not something.

  Among these, a cellulose derivative or an acrylic resin is preferable, and an acrylic resin is most preferably used.

  Further, a thermoplastic resin having a glass transition point of 110 ° C. or less, more preferably 30 to 90 ° C. is preferably used.

  In the case of polymethyl methacrylate, for example, various types having a molecular weight of tens of thousands or less to several hundreds of thousands or more and a glass transition point of 20 to 105 ° C. are commercially available, and preferable ones can be selected.

  For example, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (Negami) Manufactured by Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR-80, BR- 82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105, BR-106, The acrylic and methacrylic monomers of BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (manufactured by Mitsubishi Rayon Co., Ltd.) Various homopolymers and copolymers prepared are commercially available as charges can be suitably selected preferred resins from this.

  The glass transition point can be determined by the method described in JIS-K7121.

  The resin used here is preferably 60% by mass or more, more preferably 80% by mass or more of the whole binder used in the lower layer, and an active ray curable resin or a thermosetting resin may be added as necessary. it can. These resins are coated in a state dissolved in a suitable solvent as a binder.

  Organic solvents that can be used as the coating composition for the antistatic layer include alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, and tert-butanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetone, and acetic acid. Esters such as ethyl, methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate, ethyl butyrate, glycol ethers (propylene glycol mono (C1-C4) alkyl ethers (specifically, propylene glycol monomethyl ether (PGME), propylene glycol) Monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, etc.), propylene glycol mono (C1 -C4) alkyl ester (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate)), and other solvents.

  Although not particularly limited to these, a solvent in which these are appropriately mixed is preferably used.

  The method of applying the coating composition of the present invention includes a doctor coat, an extrusion coat, a slide coat, a roll coat, a gravure coat, a wire bar coat, a reverse coat, a curtain coat, an extrusion coat, or US Pat. No. 2,681,294. It can apply | coat so that it may become a dry film thickness of 0.1-1 micrometer normally by the extrusion coating method etc. which use the hopper described in a book.

  More preferably, it is a dry film thickness of 0.1-0.5 micrometer, Most preferably, it is a dry film thickness of 0.1-0.3.

  Furthermore, the case where the upper layer which is a clear hard-coat layer is provided on the lower layer which is an antistatic layer is demonstrated.

  In the present invention, the binder used for the upper layer is not particularly limited, but it is particularly preferable to use an actinic radiation curable resin or a thermosetting resin.

  In particular, an example of an actinic radiation curable resin layer for clear hard coat processing will be described. The actinic radiation curable resin layer refers to a layer mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams.

  Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an actinic ray other than ultraviolet rays and electron beams may be used.

  Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. I can do it.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylate) to products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate (for example, JP-A-59-151110).

  The UV curable polyester acrylate resin can generally be easily obtained by reacting a polyester polyol with 2-hydroxyethyl acrylate or 2-hydroxy acrylate monomer (for example, JP-A-59-151112).

  Specific examples of the ultraviolet curable epoxy acrylate resin include those obtained by reacting epoxy acrylate with an oligomer, a reactive diluent and a photoinitiator added thereto (for example, JP-A-1- No. 105738). As the photoreaction initiator, one or more kinds selected from benzoin derivatives, oxime ketone derivatives, benzophenone derivatives, thioxanthone derivatives and the like can be selected and used.

  Specific examples of ultraviolet curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate. Etc. can be mentioned. These resins are usually used together with known photosensitizers. Moreover, the said photoinitiator can also be used as a photosensitizer. Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, tetramethyluram monosulfide, thioxanthone, and derivatives thereof. Further, when using an epoxy acrylate photoreactant, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used.

  The photoreaction initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by mass, preferably 1 to 10 parts by mass, with respect to 100 parts by mass of the composition.

  Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, vinyl acetate, benzyl acrylate, cyclohexyl acrylate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester. The coating composition of the present invention preferably has a solid content concentration of 10 to 95% by mass, and an appropriate concentration is selected depending on the coating method.

  Examples of the ultraviolet curable resin include Adekaoptomer KR / BY series KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (manufactured by Asahi Denka Kogyo Co., Ltd.) or Koei. Hard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS-101, FT-102Q8 MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Industry Co., Ltd.), or Seika Beam PHC2210 (S), PHCX-9 (K-3), PHC2213, DP-10, DP- 20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (above Dainichi Seika Manufactured by Kogyo Co., Ltd.), or KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (above Daicel UC Corporation), or RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC -5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.) or Aulex No. 340 clear (manufactured by China Paint Co., Ltd.), Sunrad H-601 (manufactured by Sanyo Chemical Industries, Ltd.), SP-1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.), or RCC-15C (Grace Japan Co., Ltd.) (Manufactured by company), Aronix M-6100, M-8030, M-8060 (above, manufactured by Toagosei Co., Ltd.) or other commercially available products can be used as appropriate.

  As the light source for forming the cured film layer by photocuring reaction of the ultraviolet curable resin, any light source that generates ultraviolet rays can be used.

For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. The irradiation conditions vary depending on individual lamps, but the amount of light irradiated may be any degree 20~10000mJ / cm ^2, preferably from 50~2000mJ / cm ^2. From the near ultraviolet region to the visible light region, it can be used by using a sensitizer having an absorption maximum in that region.

  In order to give the cured film layer an antiglare property on the surface of the liquid crystal display panel and to prevent the adhesion to other substances, an inorganic or organic mat is used for scratch resistance. Agents can also be added.

  For example, examples of the inorganic particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, and the like, and examples of the organic particles include polymethacrylic acid. Methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder Further, it can be added to an ultraviolet curable resin composition such as polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder.

  The average particle diameter of these particle powders is 0.01 μm to 10 μm, and the ratio of the ultraviolet curable resin composition to the fine particle powder is 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin composition. It is desirable to blend so that.

  In order to impart an antiglare effect, the average particle size is preferably 0.1 to 1 μm, and 1 to 15 parts by mass with respect to 100 parts by mass of the resin composition.

  By adding such fine particles to the ultraviolet curable resin, it is possible to form an antiglare layer having preferable irregularities having a center line surface roughness Ra of 0.1 to 0.5 μm.

  Further, when such fine particles are not added to the ultraviolet curable resin composition, a good smooth surface having a center line surface roughness Ra of less than 0.05 μm, more preferably less than 0.04 μm, and even more preferably 0.00 to 0.03 μm. A clear hard coat layer can be formed.

  At this time, a preferable clear hard coat film having a haze of less than 0.5%, particularly less than 0.1% can be obtained.

  The centerline surface roughness Ra is preferably measured with an optical interference type surface roughness measuring instrument, and can be measured using, for example, RST / PLUS manufactured by WYKO.

  On these clear hard coat layers, a high refractive index layer (preferably with a refractive index of 1.65 to 1.75) and a low refractive index layer (preferably with a refractive index of 1.35 to 1.45) are formed. It is also possible to form an antireflection layer. These antireflection layers can form an excellent antireflection layer having an average reflectance of 445 to 655 nm of 0.7% or less and a minimum reflectance within this wavelength range of 0.2% or less.

  In addition, as an element that performs the blocking prevention function, 0.1 to 5 parts by mass of ultrafine particles having a volume average particle size of 0.005 to 0.1 μm with the same components as described above with respect to 100 parts by mass of the resin composition Can also be used.

On the clear hard layer etc. having the actinic radiation curable resin of the present invention, an example of the configuration further subjected to the following antireflection treatment,
Low refractive index layer (refractive index) / High refractive index layer (refractive index) / Clear hard layer / Resin film / Antistatic layer Low refractive index layer (refractive index) / High refractive index layer (refractive index) / Clear hard layer / Resin film / antistatic layer / anti-curl layer / anti-blocking layer.

  Still further, as a component that serves as an anti-blocking function, 0.1 to 5 mass of particles having a volume average particle size of 0.005 to 0.1 μm with the same components as described above with respect to 100 mass parts of the ultraviolet curable resin composition. Can also be used together.

  By coating the ultraviolet curable resin composition on the antistatic layer, the transparent resin film can be subjected to antistatic processing and clear hard processing.

  As the coating composition for the upper layer of the present invention, alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol and cyclohexanol as solvents, ketones such as methyl ethyl ketone, methyl isobutyl ketone and acetone In addition, esters such as ethyl acetate, methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate, and ethyl butyrate, hydrocarbons such as toluene and xylene, glycol ethers, and other solvents may be used alone or in an appropriate mixture.

  The solvent to be mixed is not particularly limited to these. More preferably, a solvent containing 5% by mass or more, more preferably 5-80% by mass or more of propylene glycol mono (C1-C4) alkyl ether and / or propylene glycol mono (C1-C4) alkyl ether ester is used.

  Specific examples of the propylene glycol mono (C1 to C4) alkyl ether include propylene glycol monomethyl ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, and the like. Can be given. Examples of the propylene glycol mono (C1 to C4) alkyl ether ester include propylene glycol monoalkyl ether acetate, and specific examples include propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate.

  Examples of the solvent used by mixing with propylene glycol mono (C1 to C4) alkyl ether and / or propylene glycol mono (C1 to C4) alkyl ether ester include the above-mentioned solvents, but are not particularly limited thereto. Absent.

  Since the organic solvent evaporates before ultraviolet irradiation, a drying step is required.

  In another embodiment of the present invention, it has been found that adhesion is improved by setting the temperature of the upper layer resin to a temperature equal to or higher than the glass transition point of the lower layer binder before or after curing.

  For example, if the glass transition point of the resin used for the lower layer is 85 ° C., the adhesiveness is further improved by setting the drying temperature of the upper layer to 85 ° C. or higher.

  As a method for applying the ultraviolet curable resin composition coating solution, known methods such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater, and an air doctor coater can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm in terms of wet film thickness. The coating speed is preferably 10 to 40 m / min.

  The UV curable resin composition is applied and dried, and then irradiated with UV light from a light source. The irradiation time is preferably 0.5 seconds to 5 minutes, and 3 seconds to 2 from the curing efficiency and work efficiency of the UV curable resin. Minutes are more preferred.

  The liquid crystal panel equipped with the polarizing plate protective film and the polarizing plate according to the present invention is not only used indoors like a personal computer or a word processor, but may be left in a midsummer car like a car navigation system. The plate protective film may be required to have light resistance and heat resistance.

  Therefore, in order to increase the light resistance of the cured film layer that is cured by irradiating the layer containing the ultraviolet curable resin composition with ultraviolet rays, the ultraviolet absorber is added to the ultraviolet ray to such an extent that the photocuring of the ultraviolet curable resin composition is not hindered. It may be included in the curable resin composition.

  As an ultraviolet absorber, the same thing as the ultraviolet absorber which may be contained in the said transparent plastic film can be used.

  In order to increase the heat resistance of the cured layer, an antioxidant that does not inhibit the photocuring reaction can be selected and used. Examples thereof include hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives, and the like.

  Specifically, for example, 4,4′-thiobis (6-t-3-methylphenol), 4,4′-bitylidenebis (6-t-butyl-3-methylphenol), 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4 -Hydroxy-3,5-di-t-butylbenzyl phosphate.

  By the way, when surface processing is applied only to one side of the film, or when surface processing is applied to add different types or different levels of added value on both sides, a curling phenomenon occurs in which the film is rounded. easy.

  If it curls, it is difficult to handle and inconvenient when producing a polarizing plate using this. The transparent resin of the present invention is excellent in that curling is relatively difficult to occur by using a thermoplastic resin having a weight average molecular weight of 20,000 to 400,000 in the lower layer.

  Furthermore, in order to eliminate the curling problem and prevent the function as a protective film for polarizing plate from being impaired by preventing curling, anti-curling is applied to the opposite side on which the antistatic layer and / or hard coat layer is coated. A layer can be provided.

  In other words, the degree of curling is balanced by imparting the property of curling with the surface provided with the anti-curl layer inside.

  The anti-curl layer is preferably applied also as a blocking layer, and in this case, the coating composition can contain the above-mentioned inorganic fine particles and organic fine particles for providing an anti-blocking function.

  The imparting of the anti-curl function is specifically performed by applying a composition containing a solvent for dissolving or swelling a transparent resin film used as a protective film for a polarizing plate.

  The solvent to be used may include a solvent to be dissolved and / or a solvent to be swollen in addition to a solvent to be swelled, a composition in which these are mixed at an appropriate ratio depending on the degree of curl of the transparent resin film and the type of resin, and This is done using the coating amount.

  In order to enhance the curl prevention function, it is effective to increase the mixing ratio of the solvent for dissolving the solvent composition to be used and / or the solvent for swelling, and to decrease the ratio of the solvent not to be dissolved.

  This mixing ratio is preferably (solvent to be dissolved and / or solvent to be swollen) :( solvent to be dissolved) = 10: 0 to 1: 9.

  Examples of the solvent for dissolving or swelling the transparent resin film contained in such a mixed composition include benzene, toluene, xylene, dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, and trichloroethylene. , Methylene chloride, ethylene chloride, tetrachloroethane, trichloroethane, chloroform and the like.

  Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, and n-butanol.

  These coating compositions are preferably applied to the surface of the transparent resin film using a gravure coater, a dip coater, a reverse coater, an extrusion coater, or the like, but a wet film thickness of 1 to 100 μm is preferable, and 5 to 30 μm is particularly preferable.

  Examples of the resin used here include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, and chloride. Vinyl-based vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Polymers or copolymers, cellulose derivatives such as nitrocellulose, cellulose acetate propionate, diacetyl cellulose, cellulose acetate butyrate resin, copolymers of maleic acid and / or acrylic acid, acrylic acid ester copolymers, acrylonitrile-styrene Copolymer, chlorinated poly Tylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin, polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, Examples thereof include, but are not limited to, polyether resins, polyamide resins, amino resins, rubber resins such as styrene-butadiene resins, butadiene-acrylonitrile resins, silicone resins, and fluorine resins.

  For example, as an acrylic resin, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR -80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105 BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) acrylic and The methacrylic monomers such as various homopolymers and copolymers were prepared as raw materials are commercially available and can also be selected preferred mono from this appropriate.

  Particularly preferred are cellulose resin layers such as diacetylcellulose and cellulose acetate propionate.

  The anti-curl layer may be applied before or after the opposite layer of the transparent resin film (for example, an antistatic layer or a clear hard coat layer) is applied, but the anti-curl layer also serves as an anti-blocking layer. In this case, it is desirable to apply it first.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to this Example. First, each composition used in the examples will be described.
Example 1
<Preparation of transparent resin film 1>
(Dope composition (I))
Cellulose triacetate (oxidation degree 61.0%) 100 parts by mass ethylphthalylethyl glycolate 4 parts by mass 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-6- (t-butyl) ) Phenol 1 part by mass 2-[(2H) -benzotriazol-2-yl] -4,6-di-t-pentylphenol 1 part by weight methylene chloride 430 parts by weight methanol 90 parts by weight The above composition is put into a sealed container. The solution was kept at 80 ° C. under pressure and dissolved completely with stirring.

  Next, the dope is filtered, cooled and kept at 33 ° C., uniformly cast on the stainless steel band, and the solvent is evaporated until it can be peeled off. After peeling from the stainless steel band, it is transported by many rolls. Then, drying was finished to obtain a film having a thickness of 80 μm.

The surface in contact with the stainless steel band is defined as b-plane and the other surface is defined as a-plane.
<Preparation of transparent resin film 2>
(Dope composition (b))
Polycarbonate resin (viscosity average molecular weight 40,000, bisphenol A type) 100 parts by mass 2- (2'-hydroxy-3 ', 5'-di-t-butylphenyl) benzotriazole
1.0 part by mass methylene chloride 430 parts by mass methanol 90 parts by mass The above composition was put into a sealed container, kept at 80 ° C. under pressure and completely dissolved with stirring to obtain a dope composition (b). .

  Next, this dope composition (b) was filtered, cooled, kept at 33 ° C., uniformly cast on a stainless steel band, and dried at 33 ° C. for 5 minutes. Next, the drying time was adjusted so that the retardation was 5 nm at 65 ° C., and after peeling from the stainless steel band, drying was terminated while being conveyed by a large number of rolls to obtain a polycarbonate film having a thickness of 80 μm. At this time, the side in contact with the stainless steel band is defined as b-plane, and the opposite surface is defined as a-plane.

The following composition was prepared.
Coating composition (1)
Polymethylmethacrylate (weight average molecular weight 30,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition obtained by filtering this coating composition with a 1 μm absolute filter was used as a coating composition (1). .
Coating composition (2)
Polymethyl methacrylate (weight average molecular weight 85,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition obtained by filtering this coating composition with a 1 μm absolute filter (2) It was.
Coating composition (3)
Polymethylmethacrylate (weight average molecular weight 280,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition (3) obtained by filtering this coating composition with a 1 μm absolute filter .
Coating composition (4)
Polymethyl methacrylate (weight average molecular weight 320,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition (4) obtained by filtering this coating composition with a 1 μm absolute filter. .
Coating composition (5)
Polymethylmethacrylate (weight average molecular weight 550,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition obtained by filtering this coating composition with a 1 μm absolute filter was used as a coating composition (5). .
Coating composition (6)
Polyvinyl alcohol (weight average molecular weight 10,000) 0.5 parts by mass Propylene glycol monomethyl ether 70 parts by mass Methyl ethyl ketone 30 parts by mass Further, a coating composition (6) was obtained by filtering this coating composition with a 1 μm absolute filter.
Coating composition (7)
0.2 parts by mass of polymethyl methacrylate (weight average molecular weight 60,000, glass transition point 60 ° C.)
Propylene glycol monomethyl ether 65 parts by weight Methyl ethyl ketone 20 parts by weight Ethyl lactate 5 parts by weight Methanol 10 parts by weight Conductive polymer resin (1) (average particle size 0.1 μm particles) 0.5 parts by weight

A coating composition (7) was obtained by filtering the coating composition with a filter having a particle capture efficiency of 3 μm or more of 99% or more and a particle capture efficiency of 0.5 μm or less of 10% or less.
Coating composition (8)
0.5 parts by mass of polymethyl methacrylate (weight average molecular weight 60,000, glass transition point 60 ° C.)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (8) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (9)
1.0 part by weight of polymethyl methacrylate (weight average molecular weight 60,000, glass transition point 60 ° C.)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (9) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (10)
2.0 parts by mass of polymethyl methacrylate (weight average molecular weight 60,000, glass transition point 60 ° C.)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (10) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (11)
2.5 parts by mass of polymethyl methacrylate (weight average molecular weight 60,000, glass transition point 60 ° C.)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (11) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (12)
0.5 parts by weight of polyvinyl alcohol (weight average molecular weight 100,000)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (12) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (13)
0.5 parts by weight of polyvinyl alcohol (weight average molecular weight 10,000)
Propylene glycol monomethyl ether 65 parts by mass Methyl ethyl ketone 20 parts by mass Ethyl lactate 5 parts by mass Methanol 10 parts by mass Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass Also, this coating composition is 3 μm. The coating composition (13) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (14)
0.5 parts by mass of polymethyl methacrylate (weight average molecular weight 700,000)
Propylene glycol monomethyl ether 65 parts by weight Methyl ethyl ketone 20 parts by weight Ethyl lactate 5 parts by weight Methanol 10 parts by weight Conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by weight In addition, this coating composition is 3 μm. The coating composition (14) was filtered through a filter having a particle trapping efficiency of 99% or more and a particle trapping efficiency of 0.5 μm or less of 10% or less.
Coating composition (15)
Dipentaerythritol hexaacrylate monomer 70 parts by mass Dipentaerythritol hexaacrylate dimer 15 parts by mass Dipentaerythritol hexaacrylate trimer component 15 parts by mass Diethoxybenzophenone UV initiator 2 parts by mass Polyether-modified dimethylpoly Siloxane copolymer 1 part by mass (BYK-306 Big Chemi Japan Co., Ltd.)
Propylene glycol monomethyl ether 75 parts by weight Methyl ethyl ketone 75 parts by weight A coating composition (15) was obtained by filtering this coating composition with a 1 μm absolute filter.
Coating composition (16)
Acetone 72 parts by mass Methanol 18 parts by mass Propylene glycol monomethyl ether 10 parts by mass Diacetyl cellulose 0.5 parts by mass 2% acetone-dispersed ultrafine silica Aerosil 200 0.1 parts by mass (Nippon Aerogel Co., Ltd.)
A coating composition (16) was obtained by filtering this coating composition with a 3 μm filter. Optical film examples-1 to 4, 8 to 13 and comparative samples 5 to 7 and 14 to 15 of the present invention were prepared according to the following.
<Production of Optical Film of the Present Invention and Comparative Example>
The coating composition (5) is applied to one side (a side) of the triacetyl cellulose film produced by the method for producing the transparent resin film 1 so as to have a wet film thickness of 13 μm, and is dried in a drying unit set at 80 ° C. Then, a transparent resin layer (blocking layer) was provided.

  Further, the coating compositions (1) to (14) were applied to one surface (b surface) so as to have a wet film thickness of 13 μm (dry film thickness of about 0.2 μm), and dried in a drying section set at 80 ° C. Then, a transparent resin layer (undercoat layer or antistatic layer) was provided.

A coating composition (15) is applied thereon so as to have a wet film thickness of 13 μm, dried in a drying section set at 90 ° C., cured by irradiation with ultraviolet rays at 200 mJ / cm ² , and a dry film thickness of 4 μm. Transparent resin layer (clear hard coat layer) was provided.

  In this way, optical film examples-1 to 4, 8 to 13 and comparative examples 5 to 7 and 14 to 15 of the present invention shown in Table 1 were produced.

  About these samples, the adhesiveness after ultraviolet irradiation 70 hours (Isuper UV test Iwasaki Electric Co., Ltd. product) was tested according to JIS-K5400. For Examples 8 to 13 and Comparative Examples 14 to 15 of the present invention, the surface specific resistance at 23 ° C. and 55% RH was measured. These results are shown in the table below.

Adhesion ◎ Not peeled at all ○ Partially peeled △ Half peeled off × Completely peeled surface resistivity ◎ 10 ¹⁰ Ω / cm ² or less ○ 10 ¹⁰ to 10 ¹¹ Ω / cm ²
X Exceeding 10 ¹¹ Ω / cm ² Thus, the optical film examples-1 to 4, 8-13 of the present invention produced using the composition of the present invention are compared to Comparative Examples-5-7, 14-15. It was confirmed that the adhesiveness was excellent, and in particular, the adhesiveness after ultraviolet irradiation was excellent.

Furthermore, in the case of an antistatic layer containing conductive fine particles in the lower layer, the ratio of the fine particles to the binder is in the range of 0.5 to 4.0 with respect to the fine particles 1, and both the adhesion and the surface specific resistance are excellent. I was able to confirm.
Example 2
According to the following, optical film examples -16 to 19 of the present invention and comparative optical film examples -20 to 21 were prepared.
<Production of Optical Film of the Present Invention and Comparative Example>
The coating compositions 1 to 6 are applied to one side (b side) of the polycarbonate film produced by the method for producing the transparent resin film 2 so as to have a wet film thickness of 13 μm, respectively, and dried in a drying section set at 80 ° C. A transparent resin layer (antistatic layer) was provided.

A coating composition (15) is applied thereon so as to have a wet film thickness of 13 μm, dried in a drying section set at 80 ° C., and cured by irradiation with ultraviolet rays at 150 mJ / cm ² , and a dry film thickness of 4 μm. Transparent resin layer (clear hard coat layer) was provided. In this way, optical film examples -16 to 19 and comparative examples -20 to 21 of the present invention shown in Table 2 were produced.

  About these samples, the adhesiveness after ultraviolet irradiation 80 hours (Isuper UV test Iwasaki Electric Co., Ltd. product) was tested according to JIS-K5400. Furthermore, the surface specific resistance at 23 ° C. and 55% RH was measured. The results are shown in Table 4.

Adhesiveness ◎ Not peeled at all ○ Partially peeled off △ Half peeled off × Completely peeled As described above, it was confirmed that the optical film of the present invention had improved adhesiveness compared to the comparative example.
Example 3
The coating composition of the following composition for coating an antistatic layer as a lower layer was prepared.
Coating composition (17)
Polymethyl methacrylate (weight average molecular weight 650,000, glass transition point 80 ° C.) 1.0 part by mass propylene glycol monomethyl ether 60 parts by mass methyl ethyl ketone 25 parts by mass ethyl lactate 5 parts by mass methanol 10 parts by mass conductive polymer resin (1) (0.1-0.3 μm particles) 0.5 parts by mass of coating composition (18)
Polymethyl methacrylate (weight average molecular weight 320,000, glass transition point 80 ° C.) 1.0 part by mass propylene glycol monomethyl ether 60 parts by mass methyl ethyl ketone 25 parts by mass ethyl lactate 5 parts by mass methanol 10 parts by mass conductive polymer resin (1) (0 0.5-part by weight coating composition (19)
Polymethyl methacrylate (weight average molecular weight 80,000, glass transition point 90 ° C.) 1.0 part by mass propylene glycol monomethyl ether 60 parts by mass methyl ethyl ketone 25 parts by mass ethyl lactate 5 parts by mass methanol 10 parts by mass conductive polymer resin (1) (0 0.5-part by mass These coating compositions were each filtered through a filter having a particle capture efficiency of 3 μm particles of 99% or more and a particle capture efficiency of 0.5 μm or less of 10% or less. A coating composition was obtained.
Coating composition (20)
Dianal BR-75 (manufactured by Mitsubishi Rayon Co., Ltd.) 0.6 parts by mass propylene glycol monomethyl ether 60 parts by mass methyl ethyl ketone 25 parts by mass ethyl lactate 5 parts by mass methanol 10 parts by mass conductive polymer resin (1) (average particle size 0) .15 μm particles) 0.5 parts by mass Each of these coating compositions was filtered with a filter having a particle capture efficiency of 3 μm particles of 99% or more and a particle capture efficiency of 0.5 μm or less of 10% or less. did.

  A coating composition (5) was applied to one side (a-side) of the triacetylcellulose film prepared in Example 1 so as to have a wet film thickness of 13 μm, and dried in a drying section set at 80 ° C. to obtain a transparent resin layer (Blocking layer) was provided.

  Further, the coating compositions (17) to (20) were applied to one surface (b surface) so as to have a wet film thickness of 13 μm (dry film thickness of about 0.2 μm) and dried in a drying section set at 80 ° C. Thus, a transparent resin layer (antistatic layer) was provided.

A coating composition (15) is applied thereon so as to have a wet film thickness of 13 μm, dried in a drying section set at 90 ° C., and then cured by irradiation with ultraviolet rays at 200 mJ / cm ^2. A 4 μm transparent resin layer (clear hard coat layer) was provided. Thus, the optical film examples 22-22, and 28 of this invention shown in Table 3 were created.

  Optical film examples 25 to 27 and 29 were prepared by the same method except that the coating composition (15) was applied to a wet film thickness of 13 μm and dried in a drying section set at 70 ° C.

  About these samples, the adhesiveness after ultraviolet irradiation 90 hours (Isuper UV test Iwasaki Electric Co., Ltd. product) was tested according to JIS-K5400.

  As a result, samples 22 to 24 and 28 in which the upper layer was dried at a temperature higher than the glass transition point of the binder used in the lower layer were compared to samples 25 to 17 and 29 in which the upper layer was dried at a temperature lower than the glass transition point. Furthermore, it was confirmed that the adhesiveness is excellent.

Adhesiveness ◎ Not peeled off ○ Partially peeled △ Half peeled × Completely peeled <Creation of polarizing plate>
A polarizing plate was produced according to the following method using the transparent resin film of Example 23 of the present invention as a protective film for a polarizing plate. A 120 μm thick polyvinyl alcohol film was immersed in an aqueous solution containing 1 part of iodine, 2 parts of potassium iodide, and 4 parts of boric acid, and stretched 4 times at 50 ° C. to obtain a polarizing film.

1. ~ 5. In this step, a polarizing plate was prepared by laminating the polarizing film and the polarizing plate protective film.
<Production method of polarizing plate>
1. 1. Two protective film samples cut in a longitudinal direction of 30 cm and a lateral direction of 18 cm were immersed in a 2 mol / l sodium hydroxide solution at 60 ° C. for 2 minutes, further washed with water and dried. 2. The polarizing film having the same size as the protective film sample is immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds. 2. Gently remove excess adhesive adhering to the polarizing film of 1. The protective film sample is placed on the b-side, and the above 1. 3. Laminate and arrange so that the b surface of the same sample film and the adhesive are in contact with each other. 3. Use the hand roller to Excess adhesive and bubbles are removed from the end of the laminate of the polarizing film and the protective film laminated in step 1 and bonded together. The pressure of the hand roller is about 20-30 N / cm ² and the roller speed is about 2 m / min. The sample obtained in 1 was left for 2 minutes.

  The polarizing plate thus produced was excellent in weather resistance and could withstand long-term use.

Claims (3)

  In an optical film manufacturing method in which at least two or more transparent resin layers are provided on a transparent resin film, a lower layer having a binder mainly composed of a thermoplastic resin having a weight average molecular weight of 20,000 to 400,000 is applied and dried. Then, after applying the upper layer mainly composed of actinic ray curable resin or thermosetting resin on it, when drying the upper layer, the upper layer is dried at a temperature equal to or higher than the glass transition point of the lower layer binder. A method for producing an optical film.   The method for producing an optical film according to claim 1, wherein the transparent resin film is a cellulose ester film.   The method for producing an optical film according to claim 2, wherein the upper layer contains an ultraviolet curable polyol acrylate resin.