JP2009186760A - Hard coating film, polarizing plate using the same, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard coat film used for the surface of an image display, such as, liquid crystal display (LCD), having high physical strength (crack resistant and scratch resistant properties), reducing the occurrence of foreign matter failure and application unevenness, markedly increasing staining of a large area hard coated film and improving the productivity of the large area hard coat film, and to provide a polarizing plate that uses the film and a display. <P>SOLUTION: As for the hard coat film for laminating a hard coated layer on a transparent film base material, the Martens hardness (HMs) of the surface of the hard coat layer, when pressing the surface of the hard coat layer with a micro hardness tester, be 200-300 N/mm<SP>2</SP>, and the refractive index of the hard coat layer is 1.60 or smaller. The hard coat layer is preferably conductive. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hard coat film, a polarizing plate using the same, and a display device.

  The development of the display field in recent years is remarkable, and it has been used in every scene, indoors and outdoors. It is not just for displaying still images / moving images, but, as represented by touch panels, there are many opportunities for users to directly touch the display part of the display. The demand for strength to the environment is also increasing.

  Specifically, various types such as a liquid crystal display (LCD), a plasma display panel (PDP), an electroluminescence display (ELD), a cathode ray tube display (CRT), a surface-conduction electron-emitter display (SED), etc. In an image display device, the hard coat film used on the surface is required to have high physical strength (such as scratch resistance) and antifouling properties.

  Further, in order to prevent a decrease in contrast due to reflection of external light or reflection of an image, antiglare performance and antireflection performance are required. Furthermore, measures are required to prevent dust (such as dust) that reduces the visibility of the display from adhering to the surface of the hard coat film.

  In order to enhance the surface hardness of these hard coat films, a hard coat layer is widely formed on the surface. However, when using such a hard coat layer for surface protection, dirt such as human fingerprints (sebum), sweat, and cosmetics is likely to adhere. In addition, since it is difficult to remove the dirt once adhered, there is a problem that transparency and reflectivity are impaired and visibility is deteriorated.

Therefore, in order to make it difficult for dirt to adhere to the surface of the hard coat layer and to easily remove the attached dirt, the hard coat layer surface is coated with a fluorine-based polymer, or the hard coat layer is made of fluorine-based or silicon. A method of incorporating a polymer of a system is generally performed.
In JP-A-2000-284102, the dirt resistance of an antireflection film in which a hard coat layer, a high refractive index layer, and a low refractive index layer are provided in this order on a film substrate that is a transparent support is improved. For this purpose, it is disclosed that a polymer having a perfluoroalkyl polyether side chain is applied on the low refractive index layer.

  The method described in Patent Document 1 utilizes the excellent slipperiness of a perfluoroalkyl polyether compound, protects the layer on the surface side of the antireflection film from dirt, and improves scratch resistance.

  However, since the perfluoroalkyl polyether compound described in Patent Document 1 is simply applied and formed on the surface of the low refractive index layer of the antireflection film, it easily peels off by repeated rubbing, There was a problem that the antifouling property was inferior.

  One of keywords in the display field in recent years is an increase in screen size. There is a need for a technique that can stably produce large-screen displays of 40 inches or more in large quantities.

  Large-screen displays require large-area optical films, and in order to produce large-screen displays in large quantities and stably without yield, foreign matter failures and uneven coating in large-area optical films, especially large-area hard coat films, are required. Reduction is essential.

  The object of the present invention is to solve the above-mentioned problems of the prior art, to have a high physical strength, to reduce foreign matter failure and coating unevenness, and to greatly increase the antifouling property of a large area hard coat film. An object of the present invention is to provide a hard coat film, a polarizing plate using the same, and a display device that can improve the productivity of a large area hard coat film.

  As a result of intensive studies in view of the above points, the present inventors have determined the Martens hardness of the hard coat layer surface when the hard coat layer surface is pressed into a predetermined thickness with a microhardness meter for the hard coat film. It is possible to remove a low range of the cured density of the film surface, to prevent deterioration of the antifouling property of the film surface, and to remove a range of fragility (flexibility deterioration) of the film surface It is possible to avoid problems such as the occurrence of cracks during the production of hard coat films, which can greatly increase the antifouling property of large area hard coat films. We found that productivity could be improved.

  In addition, in the hard coat film, the present inventor defines the refractive index of the hard coat layer to 1.60 or less, so that when the application unevenness occurs during the production of the large area hard coat film, the application unevenness is reduced. It has been found that it can be difficult to visually recognize and can improve the productivity of a large-area hard coat film, and the present invention has been completed.

In order to achieve the above object, the invention of claim 1 is a hard coat film in which a hard coat layer is laminated on a transparent film substrate, and the hard coat layer is hardened when the surface of the hard coat layer is pressed with a microhardness meter. The Martens hardness (HMs) of the coat layer surface is 200 N / mm ² or more and 300 N / mm ² or less, and the refractive index of the hard coat layer is 1.60 or less.

  Here, the Martens hardness (HMs) on the surface of the hard coat layer is a microhardness meter using a Vickers indenter and a triangular pyramid indenter having an angle between ridges of 115 degrees (for example, trade name, DUH-211, manufactured by Shimadzu Corporation). In the load test force-indentation depth curve when the indenter is pushed down to the thickness of about 1/10 of the thickness of the hard coat layer, the load test force-indentation depth curve From the slope (m) in which the indentation depth from the 50% value to the 90% value of the maximum load test force (Fmax) obtained from is proportional to the square root of the load test force, it is a value defined by the following equation.

HMs = 1 / (26.43 m ² )
The invention of claim 2 is the hard coat film of claim 1, characterized in that the hard coat layer has conductivity.

  The invention of the polarizing plate according to claim 3 is characterized in that the hard coat film according to claim 1 or 2 is bonded to at least one of the two surfaces of the polarizer.

  The invention of the display device of claim 4 is characterized in that the hard coat film of claim 1 or 2 is used.

  The invention of the display device according to claim 5 is characterized in that the polarizing plate according to claim 3 is used.

The invention of claim 1 is a hard coat film in which a hard coat layer is laminated on a transparent film substrate, and the Martens hardness (HMs) of the hard coat layer surface when the hard coat layer surface is pressed with a microhardness meter. ) Is 200 N / mm ² or more and 300 N / mm ² or less, and the refractive index of the hard coat layer is 1.60 or less. According to the hard coat film invention of claim 1, By defining the surface of the layer with the Martens hardness of the hard coat layer surface when a microhardness meter is pushed into it, it has a high physical strength and can reduce foreign matter failure and coating unevenness. The effect that the antifouling property of the coated film can be greatly increased and the productivity of the large area hard coated film can be improved. Achieve the.

  The invention according to claim 2 is the hard coat film according to claim 1, wherein the hard coat layer has conductivity, and according to the hard coat film invention of claim 2, the hard coat layer is conductive. Therefore, the occurrence of foreign matter failure is reduced, the yield is reduced, and the productivity of the large area hard coat film can be expected to be further improved.

  The invention of the polarizing plate according to claim 3 uses the hard coat film having high physical strength and antifouling property according to claim 1 or 2 on at least one of both surfaces of the polarizing plate. Thus, according to the invention of the polarizing plate of claim 3, when this is used for a display device, the antifouling durability of the hard coat film surface is excellent, and there is an effect that the visibility is excellent.

  The invention of the display device according to claim 4 uses the hard coat film having high physical strength and antifouling property according to claim 1 or 2. According to the invention of the display device of claim 4, the hard coat film is used. The antifouling durability of the surface is excellent, and there is an effect that the visibility is excellent.

  The display device according to claim 5 uses the polarizing plate according to claim 3, and according to the display device according to claim 5, the scratch resistance and antifouling durability are excellent, and the visibility is excellent. There is an effect that.

  Next, embodiments of the present invention will be described, but the present invention is not limited thereto.

The hard coat film according to the present invention is a hard coat film in which a hard coat layer is laminated on a transparent film substrate, and the Martens hardness of the hard coat layer surface when the hard coat layer surface is pressed with a microhardness meter ( HMs) is 200 N / mm ² or more and 300 N / mm ² or less, preferably 230 N / mm ² or more, 270 N / mm ² or less, desirably 240 N / mm ² or more and 260 N / mm ² or less, and a hard coat layer Has a refractive index of 1.60 or less.

  Here, the definition of the Martens hardness (HMs) on the hard coat layer surface is as described above. The Martens hardness (HMs) of the hard coat layer surface is the Martens hardness (HMs) when the hard coat layer surface is pressed by a microhardness meter by a thickness of about 1/10 of the thickness of the hard coat layer. means.

  In general, the hard coat layer of the hard coat film has a Martens hardness (HMs) value on the surface of the hard coat layer that varies depending on the composition of the resin composition for forming the hard coat layer. The hard coat film according to the invention is defined by the Martens hardness of the hard coat layer surface.

Here, if the Martens hardness (HMs) on the surface of the hard coat layer is less than 200 N / mm ² , the surface antifouling property deteriorates because the cured density of the film surface is low. Also, it is not preferable to apply a coating solution having another function to the upper layer because the so-called base is loose, and the solvent contained in the coating solution penetrates into the lower layer.

Conversely, when the Martens hardness (HMs) of the hard coat layer surface exceeds 300 N / mm ² , the film surface becomes over-cured and the brittleness (flexibility degradation) increases, and for example, roll to roll (role To role), cracks are generated during production, and resin pieces are generated from the generated cracks, leading to foreign matter failure. Moreover, it is not preferable to apply a coating solution having another function to the upper layer because the solvent contained in the coating solution penetrates into the lower layer from the crack portion.

  As described above, the larger the production area of the hard coat film, the higher the probability of occurrence of foreign matter failure and uneven coating due to cracks in the hard coat layer. Therefore, according to the present invention, the Martens hardness (HMs) of the hard coat layer surface is reduced. By keeping within the specified range, the yield can be reduced even if the production area is large.

  Furthermore, in the hard coat film according to the present invention, when the refractive index of the hard coat layer laminated on the transparent film substrate is 1.60 or less, when uneven coating occurs during the production of the hard coat film. The coating unevenness can be made difficult to visually recognize, leading to an improvement in productivity of the hard coat film.

  In the hard coat film of the present invention, the hard coat layer preferably has conductivity. Thus, by having conductivity in the hard coat film, occurrence of foreign matter failure is reduced, yield is reduced, and further improvement in productivity can be expected.

  The conductivity of the hard coat film is preferably imparted by adding conductive particles or alternatively a conductive polymer.

  Next, a transparent film substrate that can be used in the hard coat film of the present invention will be described.

(Transparent film substrate)
The transparent film substrate used in the hard coat film of the present invention is easy to manufacture, has good adhesion to the actinic radiation curable resin layer, is optically isotropic, and optically It is mentioned as preferable requirements that it is transparent.

  In the present invention, the transparent film substrate is particularly preferably 1.4 to 4 m from the viewpoint of planarity.

  The term “transparent” as used in the present invention means that the visible light transmittance is 60% or more, preferably 80% or more, and particularly preferably 90% or more.

  Although it will not specifically limit if it has said property, For example, a cellulose-ester-type film, a polyester-type film, a polycarbonate-type film, a polyarylate-type film, a polysulfone (a polyethersulfone is also included) film, a polyethylene terephthalate, polyethylene Polyester film such as naphthalate, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose triacetate, cellulose acetate propionate film, cellulose acetate butyrate film, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, Syndiotactic polystyrene film, polycarbonate film, cycloolefin Polymer film (Arton, manufactured by JSR), ZEONEX, ZEONOR (above, manufactured by Nippon Zeon), polymethylpentene film, polyetherketone film, polyetherketoneimide film, polyamide film, fluororesin film, nylon film, polymethyl A methacrylate film, an acrylic film, a glass plate, etc. can be mentioned. Among them, cellulose triacetate film, polycarbonate film, and polysulfone (including polyethersulfone) are preferable, and in the present invention, cellulose ester film (for example, Konica Minolta Tack, product names KC8UX2MW, KC4UX2MW, KC8UY, KC4UY, KC5UN, KC12UR, KC8UCR -3, KC8UCR-4, KC8UCR-5, KC4UEW, KC4FR-1, KC4FR-2 (manufactured by Konica Minolta Opto Co., Ltd.) from the viewpoint of manufacturing, cost, transparency, isotropic properties, adhesiveness, etc. Preferably used. These films may be films produced by melt casting film formation or films produced by solution casting film formation.

(Cellulose ester)
In the present invention, it is preferable to use a cellulose ester film as the transparent film substrate. As the cellulose ester, cellulose acetate, cellulose acetate butyrate, and cellulose acetate propionate are preferable. Among these, cellulose acetate butyrate, cellulose acetate phthalate, cellulose acetate propionate, and cellulose acetate butyrate are preferably used.

  Particularly preferred are those having a mixed fatty acid ester of cellulose where X and Y are in the following ranges, where X is the substitution degree of the acetyl group and Y is the substitution degree of the propionyl group or butyryl group.

2.3 ≦ X + Y ≦ 3.0 0.1 ≦ Y ≦ 2.0
In particular, it is preferable that 2.4 ≦ X + Y ≦ 2.9 0.3 ≦ Y ≦ 1.5.

  When a cellulose ester is used as the transparent film substrate used in the present invention, the cellulose used as the raw material for the cellulose ester is not particularly limited, and examples include cotton linters, wood pulp (derived from coniferous trees, derived from hardwoods), kenaf, and the like. Can do. Moreover, the cellulose ester obtained from them can be mixed and used in arbitrary ratios, respectively. When the acylating agent is an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride), these cellulose esters use an organic solvent such as acetic acid or an organic solvent such as methylene chloride, and It can be obtained by reacting with a cellulose raw material using a protic catalyst.

When the acylating agent is acid chloride (CH ₃ COCl, C ₂ H ₅ COCl, C ₃ H ₇ COCl), the reaction is carried out using a basic compound such as an amine as a catalyst. Specifically, it can be synthesized with reference to the method described in JP-A-10-45804. In addition, the cellulose ester used in the present invention is obtained by mixing and reacting the amount of the acylating agent in accordance with the degree of substitution. In the cellulose ester, these acylating agents react with hydroxyl groups of cellulose molecules. Cellulose molecules are composed of many glucose units linked together, and the glucose unit has three hydroxyl groups. The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution (mol%). For example, cellulose triacetate has acetyl groups bonded to all three hydroxyl groups of the glucose unit (actually 2.6 to 3.0).

  As the degree of substitution of the cellulose ester used in the present invention, the cellulose ester in which the 2-position, 3-position, and 6-position may be substituted with an acyl group on average, or the 6-position is more or less substituted is also preferably used. It is done. The substitution degree at the 6-position is preferably 0.7 to 0.97, more preferably 0.8 to 0.97.

  As the cellulose ester used in the present invention, a mixed fatty acid ester of cellulose in which a propionate group or a butyrate group is bonded in addition to an acetyl group such as cellulose acetate propionate, cellulose acetate butyrate, or cellulose acetate propionate butyrate Is particularly preferably used. The butyryl group that forms butyrate may be linear or branched.

  Cellulose acetate propionate containing a propionate group as a substituent has excellent water resistance and is useful as a film for liquid crystal image display devices.

  The measuring method of the substitution degree of an acyl group can be measured according to the rule of ASTM-D817-96.

  The number average molecular weight of the cellulose ester is preferably 70000 to 250,000, since it has high mechanical strength when molded and an appropriate dope viscosity, and more preferably 80000 to 150,000.

  These cellulose ester films are pressed by a cellulose ester solution (dope), generally called a solution casting film forming method, onto an endless metal belt for infinite transport or a support for casting of a rotating metal drum, for example. It is preferable to manufacture the dope from a die by casting (casting).

(Organic solvent)
As the organic solvent used for preparing these dopes, it is preferable that the cellulose ester can be dissolved and has an appropriate boiling point, such as methylene chloride, methyl acetate, ethyl acetate, amyl acetate, methyl acetoacetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, 1,3-difluoro-2- Propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3 3,3-pentafluoro-1-propanol, nitroethane, 1,3-dimethyl-2-imidazolidinone, etc. DOO but can, methylene chloride organic halogen compounds such as chloride, dioxolane derivatives, methyl acetate, ethyl acetate, acetone, methyl acetoacetate, and the like are preferable organic solvents (i.e., good solvent), and as.

  Moreover, as shown in the following film forming process, it is used from the viewpoint of preventing foaming in the web when the solvent is dried from the web (dope film) formed on the casting support in the solvent evaporation process. The boiling point of the organic solvent is preferably 30 to 80 ° C. For example, the good solvent described above has a boiling point of methylene chloride (boiling point 40.4 ° C), methyl acetate (boiling point 56.32 ° C), acetone (boiling point 56.3). ° C), ethyl acetate (boiling point 76.82 ° C), and the like.

  Among the good solvents described above, methylene chloride or methyl acetate, which is excellent in solubility, is preferably used.

  In addition to the organic solvent, it is preferable to contain 0.1 to 40% by mass of an alcohol having 1 to 4 carbon atoms. It is particularly preferable that the alcohol is contained at 5 to 30% by mass. After casting the dope described above onto a casting support, the solvent starts to evaporate and the alcohol ratio increases and the web (dope film) gels, making the web strong and peeling from the casting support. It is also used as a gelling solvent for facilitating the dissolution, and when these ratios are small, it also has a role of promoting dissolution of the cellulose ester of the non-chlorine organic solvent.

  Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol and the like.

  Of these solvents, ethanol is preferred because it has good dope stability, relatively low boiling point, good drying properties, and no toxicity. It is preferable to use a solvent containing 5 to 30% by mass of ethanol with respect to 70 to 95% by mass of methylene chloride. Methyl acetate can be used in place of methylene chloride. At this time, the dope may be prepared by a cooling dissolution method.

  Alternatively, methylene chloride and methyl acetate can be used in combination, for example, in a mass ratio of 10.1 to 3. It is preferable to further contain the alcohol described above.

(Plasticizer)
When using a cellulose ester film for the transparent film substrate of the hard coat film of the present invention, it is preferable to contain the following plasticizer. Examples of plasticizers include phosphate ester plasticizers, phthalate ester plasticizers, trimellitic acid ester plasticizers, pyromellitic acid plasticizers, glycolate plasticizers, citrate ester plasticizers, and polyesters. A plasticizer, a polyhydric alcohol ester plasticizer, or the like can be preferably used.

  For phosphate plasticizers, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenylbiphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. For phthalate ester plasticizers, diethyl phthalate, dimethoxy For trimellitic acid plasticizers such as ethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, diphenyl phthalate, dicyclohexyl phthalate, tributyl trimellitate, triphenyl trimellitate, triethyl For pyromellitic acid ester plasticizers such as trimellitate, tetrabutylpyromellitate, In the case of glycolate plasticizers such as lupyromelitate and tetraethylpyromellitate, triacetin, tributyrin, ethylphthalylethyl glycolate, methylphthalylethyl glycolate, butylphthalylbutyl glycolate, etc. Citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used. Examples of other carboxylic acid esters include trimethylolpropane tribenzoate, butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  The polyhydric alcohol ester plasticizer is a plasticizer composed of an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  As the polyester plasticizer, a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used. As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.

  The amount of these plasticizers used is preferably from 1 to 20% by mass, particularly preferably from 3 to 13% by mass, based on the cellulose ester, in terms of film performance, processability and the like.

(UV absorber)
When a cellulose ester film is used for the transparent film substrate of the hard coat film of the present invention, an ultraviolet absorber is preferably used. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having a small absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties.

  Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, oxybenzophenone compounds, benzotriazole compounds, triazine compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. For example, but not limited to.

  Specific examples of the benzotriazole-based ultraviolet absorbers include the following ultraviolet absorbers, but the present invention is not limited thereto.

UV-1: 2- (2'-hydroxy-5'-methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) benzotriazole UV-3 : 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-tert-butylphenyl)- 5-Chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ", 4", 5 ", 6" -tetrahydrophthalimidomethyl) -5'-methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol)
UV-7: 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2- (2H-benzotriazol-2-yl) -6 (Linear and side chain dodecyl) -4-methylphenol (TINUVIN171, manufactured by Ciba)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- Mixture of 4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN 109, manufactured by Ciba)
Moreover, although the following specific example is shown as a benzophenone series ultraviolet absorber, this invention is not limited to these.

UV-10: 2,4-dihydroxybenzophenone UV-11: 2,2'-dihydroxy-4-methoxybenzophenone UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-13: Bis (2-methoxy -4-hydroxy-5-benzoylphenylmethane)
As the ultraviolet absorber preferably used in the present invention, a benzotriazole-based ultraviolet absorber and a benzophenone-based ultraviolet absorber that are highly transparent and excellent in preventing the deterioration of the polarizing plate and the liquid crystal are preferable, and unnecessary coloring is less. A benzotriazole-based ultraviolet absorber is particularly preferably used.

  Moreover, the ultraviolet absorber whose distribution coefficient described in Unexamined-Japanese-Patent No. 2001-187825 is 9.2 or more improves the surface quality of a long film, and is excellent also in applicability | paintability. In particular, it is preferable to use an ultraviolet absorber having a distribution coefficient of 10.1 or more.

  Further, the polymer ultraviolet ray described in the general formula (1) or general formula (2) described in JP-A-6-148430 and the general formulas (2), (6), and (7) described in Japanese Patent Application No. 2000-156039. Absorbers (or UV absorbing polymers) are also preferably used. As a polymer ultraviolet absorber, PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like are commercially available.

(Fine particles)
Moreover, when using a cellulose-ester film for the transparent film base material of the hard coat film of this invention, in order to provide slipperiness to the cellulose-ester film used for this invention, the following microparticles | fine-particles can be used.

  As fine particles, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, Mention may be made of magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle size of the fine particles is preferably 5 to 50 nm, and more preferably 7 to 20 nm. These are preferably contained mainly as secondary aggregates having a particle size of 0.05 to 0.3 μm. The content of these fine particles in the cellulose ester film is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.5% by mass. In the case of a cellulose ester film having a multilayer structure by the co-casting method, it is preferable to contain fine particles of this addition amount on the surface.

  Silicon dioxide fine particles are commercially available under the trade names of, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.). .

  Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.), and can be used.

  Polymer fine particles can also be used, and examples thereof include silicone resin, fluororesin, and acrylic resin. Among these, silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120 and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed under the trade name of and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the turbidity of the cellulose ester film low.

(Method for producing cellulose ester film)
The cellulose ester film used in the present invention can be preferably used regardless of whether it is produced by a solution casting film forming method or a melt casting film forming method.

  Hereinafter, a method for producing a cellulose ester film will be described by taking a solution casting film forming method as an example.

  The cellulose ester film is produced by dissolving the cellulose ester and additives in a solvent to prepare a dope, casting the dope on a belt-like or drum-like metal support, and drying the cast dope as a web. It is performed by the process of carrying out, the process of peeling from a metal support body, the process of extending | stretching or maintaining width, the process of drying further, and the process of winding up the finished film.

  The process for preparing the dope will be described. The concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced. However, if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy increases. Becomes worse. The concentration for achieving both of these is preferably 10 to 35% by mass, and more preferably 15 to 25% by mass.

  The solvent used in the dope may be used alone or in combination of two or more, but it is preferable to use a mixture of a good solvent and a poor solvent of cellulose ester in terms of production efficiency, and there are many good solvents. This is preferable from the viewpoint of the solubility of the cellulose ester. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose ester to be used independently is defined as a good solvent, and what poorly swells or does not melt | dissolve is defined as a poor solvent. Therefore, depending on the acyl group substitution degree of the cellulose ester, the good solvent and the poor solvent change. For example, when acetone is used as the solvent, the cellulose ester acetate ester (acetyl group substitution degree 2.4) and cellulose acetate propionate are good. As a solvent, cellulose acetate (acetyl group substitution degree 2.8) is a poor solvent.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone etc. are used preferably. Moreover, it is preferable that 0.01-2 mass% of water contains in dope.

  As a method for dissolving the cellulose ester when preparing the dope, a general method can be used. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamacos. Moreover, after mixing a cellulose ester with a poor solvent and making it wet or swell, the method of adding a good solvent and melt | dissolving is also used preferably.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  A higher heating temperature with the addition of a solvent is preferable from the viewpoint of the solubility of the cellulose ester. However, if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  A cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose ester solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like. However, if the absolute filtration accuracy is too small, there is a problem that the filter medium is likely to be clogged. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is more preferable.

  There are no particular restrictions on the material of the filter medium, and ordinary filter media can be used. However, plastic filter media such as polypropylene and Teflon (registered trademark), and metal filter media such as stainless steel do not drop off fibers. preferable. It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose ester by filtration.

A bright spot foreign substance is when two polarizing plates are placed in a crossed Nicol state, a cellulose ester film is placed between them, light is applied from the side of one polarizing plate, and observed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side appears to leak, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by a normal method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and even more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

  Next, dope casting will be described.

  The metal support in the casting (casting) step preferably has a mirror-finished surface. As the metal support, a stainless steel belt or a drum whose surface is plated with a casting is preferably used. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is set to −50 ° C. to a temperature at which the solvent boils and does not foam. Higher temperatures are preferable because the web can be dried faster, but if the temperature is too high, the web may foam or flatness may deteriorate. A preferable metal support temperature is appropriately determined at 0 to 100 ° C, and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use hot water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. . In particular, it is preferable to efficiently dry by changing the temperature of the metal support and the temperature of the drying air during the period from casting to peeling.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
Where M is the mass of a sample taken during or after production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Further, in the drying step of the cellulose ester film, the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Especially preferably, it is 0-0.01 mass% or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a tenter method is used while drying the web.

  In order to produce the cellulose ester film for a hard coat film of the present invention, the web is stretched in the conveying direction immediately after peeling from the metal support where the residual solvent amount is large, and both ends of the web are held with clips or the like. It is particularly preferable to perform stretching in the width direction by a tenter method. The preferred draw ratio in both the machine direction and the transverse direction is 1.05 to 1.5 times, more preferably 1.05 to 1.3 times, and even more preferably 1.05 to 1.15 times. It is preferable that the area is 1.1 to 2 times by longitudinal and lateral stretching. This can be determined by the draw ratio in the longitudinal direction × the draw ratio in the transverse direction.

  In order to stretch in the machine direction immediately after peeling, it is preferable to stretch by peeling tension and subsequent transport tension. For example, it is preferable to peel at a peeling tension of 210 N / m or more, and particularly preferably 220 to 300 N / m.

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably increased stepwise from 30 to 150 ° C, and more preferably in the range of 50 to 140 ° C in order to improve dimensional stability.

  Although the film thickness of a cellulose-ester film is not specifically limited, 10-200 micrometers is used preferably. Particularly, it was difficult to obtain a hard coat film excellent in flatness and hardness with a thin film of 10 to 70 μm, but according to the present invention, a thin hard coat film excellent in flatness and hardness was obtained, Moreover, since it is excellent also in productivity, it is especially preferable that the film thickness of a cellulose-ester film is 10-70 micrometers. More preferably, it is 20-60 micrometers. Most preferably, it is 30-60 micrometers. Moreover, the cellulose ester film made into the multilayer structure by the co-casting method can also be used preferably. Even when the cellulose ester has a multilayer structure, it has a layer containing an ultraviolet absorber and a plasticizer, and it may be a core layer, a skin layer, or both.

  In addition, as a film forming process of the thermoplastic resin film, there are a solution casting film forming method and a melt casting film forming method, but in the present invention, a transparent film substrate manufactured by either method may be used. .

  Next, the hard coat layer of the hard coat film according to the present invention will be described.

  In the production of the hard coat film according to the present invention, an active energy ray-curable resin can be preferably used for the hard coat layer.

  The active energy ray-curable resin refers to a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and the active energy ray curable type is cured by irradiation with an active energy ray such as an ultraviolet ray or an electron beam. A resin layer is formed. Typical examples of the active energy ray-curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin that is cured by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferably used. It is done. Of these, ultraviolet curable acrylate resins are preferred.

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

  For example, a mixture of 100 parts Unidic 17-806 (Dainippon Ink Chemical Co., Ltd.) and 1 part Coronate L (Nihon Polyurethane Co., Ltd.) is preferably used.

  Examples of UV curable polyester acrylate resins include those which are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Those described in the publication can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photopolymerization initiator added thereto, and reacted to form an oligomer. Those described in Japanese Patent No. 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. Can be mentioned.

  Specific examples of photopolymerization initiators for these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photopolymerization initiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photopolymerization initiator, a sensitizer such as n-butylamine, triethylamine, tri-n-butylphosphine can be used. The photopolymerization initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 20 parts by mass, preferably 1 to 15 parts by mass with respect to 100 parts by mass of the composition.

  Examples of the resin monomer may include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene. Further, as monomers having two or more unsaturated double bonds, ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, dioxane glycol diacrylate, 1,4-cyclohexyldimethyl adiacrylate, Examples include methylolpropane triacrylate and pentaerythritol tetraacrylic ester.

  Examples of commercially available ultraviolet curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi Denka Co., Ltd.) Manufactured by company); KEIEI 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 Co., Ltd.); Seika Beam PHC2210 (S), PHCX-9 (K-3), PHC2213, DP-10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UC Corporation); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC- 5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (Dainippon Ink & Chemicals, Inc.); 340 clear (manufactured by China Paint Co., Ltd.); Sun Rad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (Sanyo Chemical Industries Co., Ltd.); SP-1509 , SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.); NK Hard B-420 , B-500, NK ester A-DOG (manufactured by Shin-Nakamura Chemical Co., Ltd.) and the like can be appropriately selected and used.

  Other examples include ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, isobornyl acrylate, and the like.

The irradiation conditions for the photocuring reaction vary depending on the mercury lamp and the like, but the irradiation amount of the active energy ray is usually 5 to 500 mJ / cm ² , preferably 5 to 150 mJ / cm ² , particularly preferably 20 to 100 mJ / cm ² .

  Moreover, when irradiating an active energy ray, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the transport direction on the back roll, or tension may be applied in the width direction or biaxial direction by a tenter. This makes it possible to obtain a film having further excellent flatness.

  In forming the hard coat layer, in addition to the above resins, a photoreaction initiator, a photosensitizer, an antioxidant, an ultraviolet absorber, an antistatic agent, inorganic fine particles, organic fine particles, and the like are appropriately added. Can do.

  As a plasticizer that can be used in the hard coat layer, for example, phosphate ester plasticizer, phthalate ester plasticizer, trimellitic ester plasticizer, pyromellitic acid plasticizer, glycolate plasticizer, A citrate ester plasticizer, a polyester plasticizer, or the like can be preferably used.

  Examples of phosphate ester plasticizers include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, and tributyl phosphate. For trimellitic plasticizers such as phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, butyl benzyl phthalate, diphenyl phthalate, dicyclohexyl phthalate, tributyl trimellitate, triphenyl trimellitate For pyromellitic acid ester plasticizers such as tate and triethyl trimellitate, tetrabutyl pyromellitate For glycolate plasticizers such as tetraphenylpyromellitate and tetraethylpyromellitate, triacetin, tributyrin, ethylphthalylethyl glycolate, methylphthalylethyl glycolate, butylphthalylbutyl glycolate, etc., citrate plastics As the agent, triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl tri-n- (2-ethylhexyl) citrate and the like can be preferably used. Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters.

  As the polyester plasticizer, a copolymer of a dibasic acid and a glycol such as an aliphatic dibasic acid, an alicyclic dibasic acid, or an aromatic dibasic acid can be used. The aliphatic dibasic acid is not particularly limited, and adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyl dicarboxylic acid, and the like can be used. As glycol, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more.

  In particular, cellulose esters having additives such as epoxy compounds, rosin compounds, phenol novolac type epoxy resins, cresol novolac type epoxy resins, ketone resins, and toluenesulfonamide resins described in JP-A No. 2002-146044 are also preferably used. It is done.

  As the above compounds, KE-604 and KE-610 are commercially available from Arakawa Chemical Industries, Ltd. with acid values of 237 and 170, respectively. Similarly, KE-100 and KE-356 are commercially available from Arakawa Chemical Industries, Ltd. as an esterified product of a mixture of abietic acid, dehydroabietic acid, and parastrinic acid with acid values of 8 and 0, respectively. A mixture of abietic acid, dehydroabietic acid, and parastrinic acid is commercially available from Harima Kasei Co., Ltd. in G-7 and Hartole RX with acid values of 167 and 168, respectively.

  As the epoxy resin, Araldide EPN1179 and Araldide AER260 are commercially available from Asahi Ciba.

  As the ketone resin, Hilac 110 and Hilac 110H are commercially available from Hitachi Chemical.

  As para-toluenesulfonamide resin, it is marketed from Fujiamide Chemical Co., Ltd. as a topler.

  In the present invention, the solvent for coating the hard coat layer is appropriately selected from, for example, hydrocarbons, alcohols, ketones, esters, glycol ethers, and other solvents, or used in combination. it can. Preferably, a solvent containing 5% by mass or more, more preferably 5% by mass to 80% by mass or more of propylene glycol mono (C1-C4) alkyl ether or propylene glycol mono (C1-C4) alkyl ether ester is used.

  As a method of applying the composition coating liquid for hard coat layer having the above-described composition on the transparent film substrate, gravure coater, spinner coater, wire bar coater, roll coater, reverse coater, extrusion coater, air doctor coater, etc. A known method can be used. The coating amount is suitably 5 μm to 30 μm, preferably 10 μm to 20 μm in terms of wet film thickness. The coating speed is preferably 10 m / min to 60 m / min. Moreover, as a dry film thickness maintenance, 1-10 micrometers is preferable.

  From the viewpoint of the object effect of the present invention, the hard coat layer is desirably conductive. In order to impart conductivity to the hard coat layer, it is preferable to contain conductive particles or a conductive polymer.

  The conductive particles used for the hard coat layer of the hard coat film of the present invention will be described.

  The conductive particles used in the present invention are at least one selected from the group consisting of antimony oxide, tin oxide, zinc oxide, tin indium acid (ITO), tin antimonate (ATO), and zinc antimonate. Conductive particles.

  The average particle diameter of primary particles of these conductive particles is in the range of 10 nm to 200 nm, more preferably 20 to 150 nm, and particularly preferably 30 to 100 nm. The average particle diameter of the conductive particles can be measured from an electron micrograph taken with a scanning electron microscope (SEM) or the like. Further, it may be measured by a particle size distribution meter using a dynamic light scattering method or a static light scattering method. If the particle size is too small, aggregation tends to occur and the dispersibility deteriorates. If the particle size is too large, the haze is remarkably increased. The shape of the conductive particles is preferably a rice grain shape, a spherical shape, a cubic shape, a spindle shape, a needle shape, or an indefinite shape.

  The conductive particles may be surface-treated with an organic compound. By modifying the surface of the conductive particles with an organic compound, the dispersion stability in an organic solvent is improved, the control of the dispersed particle size is facilitated, and aggregation and sedimentation over time can be suppressed. For this reason, the surface modification amount with a preferable organic compound is 0.1-5 mass% with respect to metal oxide particle, More preferably, it is 0.5-3 mass%. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Among these, the silane coupling agent mentioned later is preferable. Two or more surface treatments may be combined.

  5 mass%-85 mass% is preferable in a hard-coat layer, as for the usage-amount of electroconductive particle, it is more preferable that it is 10-80 mass%, and 20-75 mass% is the most preferable. If the amount used is small, the desired refractive index cannot be obtained, and if it is too large, the film strength deteriorates.

  The said electroconductive particle is provided to the coating liquid for forming a hard-coat layer in the state of the dispersion disperse | distributed to the medium. As a dispersion medium for metal oxide particles, it is preferable to use a liquid having a boiling point of 60 to 170 ° C. Specific examples of the dispersion solvent include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ketone alcohol (eg, diacetone alcohol). , Esters (eg, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), halogenated hydrocarbons (eg, methylene) Chloride, chloroform, carbon tetrachloride), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ethers (eg, diethyl ether, dioxane, Tiger hydrofuran), ether alcohols (e.g., 1-methoxy-2-propanol), propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate. Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and methanol, ethanol, and isopropanol are particularly preferable.

  Moreover, electroconductive particle can be disperse | distributed in a medium using a disperser. Examples of the disperser include a sand grinder mill (eg, a bead mill with pins), a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder. It is also preferable to contain a dispersant.

  Furthermore, you may contain the electroconductive particle which has a core / shell structure. One layer of the shell may be formed around the core, or a plurality of layers may be formed in order to further improve the light resistance. The core is preferably completely covered by the shell. In addition, the hard coat layer contains an ionizing radiation curable resin as a binder for conductive particles in order to improve the film forming property and physical properties of the coating film.

  Next, the conductive polymer will be described.

  The conductive polymer used in the present invention is a π-conjugated conductive polymer, and any organic polymer whose main chain is composed of a π-conjugated system can be used. Examples thereof include polythiophenes, polypyrroles, polyanilines, polyphenylenes, polyacetylenes, polyphenylene vinylenes, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of ease of polymerization and stability, polythiophenes, polypyrroles, and polyanilines are preferred.

  π-conjugated conductive polymer can provide sufficient conductivity and solubility in binder resin even if it is not substituted. However, in order to further improve conductivity and solubility, alkyl group, carboxy group, sulfo group, alkoxy A functional group such as a group, a hydroxy group, or a cyano group may be introduced.

  Specific examples of such π-conjugated conductive polymers include polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3 -Cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythio) ), Poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene) , Poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4 -Dioctyloxythiophene), poly (3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedi) Oxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly Li (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl -4-carboxybutylthiophene), polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-N-propylpyrrole), poly (3-butylpyrrole) ), Poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3- Carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole) Poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyl) Oxypyrrole), poly (3-methyl-4-hexyloxypyrrole), polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfone) Acid) and the like. Each of these may be used alone or two types of copolymers can be suitably used.

  A dopant component may be added to these π-conjugated conductive polymers. Examples of the dopant component include low molecular weight dopants such as halogens, Lewis acids, proton acids, transition metal halides, and polymers such as polyanions.

  A polyanion is a polymer having an anionic group that functions as a dopant for a π-conjugated conductive polymer, and is a substituted or unsubstituted polyalkylene, a substituted or unsubstituted polyalkenylene, a substituted or unsubstituted polyimide, a substituted or unsubstituted Substituted polyamides, substituted or unsubstituted polyesters, and copolymers thereof, comprising a structural unit having an anionic group and a structural unit having no anionic group.

  Polyalkylene is a polymer whose main chain is composed of repeating methylene, and examples thereof include polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyvinyl alcohol, polyvinylphenol, polyacrylonitrile, polyacrylate, polystyrene, and the like.

  Polyalkenylene is a polymer composed of structural units containing one or more unsaturated bonds in the main chain. For example, propenylene, 1-methylpropenylene, 1-butylpropenylene, 1-decylpropenylene, 1-cyanopropene. Nylene, 1-phenylpropenylene, 1-hydroxypropenylene, 1-butenylene, 1-methyl-1-butenylene, 1-ethyl-1-butenylene, 1-octyl-1-butenylene, 2-methyl-1-butenylene, 2-ethyl-1-butenylene, 2-butyl-1-butenylene, 2-hexyl-1-butenylene, 2-octyl-1-butenylene, 2-decyl-1-butenylene, 2-phenyl-1-butenylene, 2- Butenylene, 1-methyl-2-butenylene, 1-ethyl-2-butenylene, 1-octyl-2-butenylene, 2 Methyl-2-butenylene, 2-ethyl-2-butenylene, 2-butyl-2-butenylene, 2-hexyl-2-butenylene, 2-octyl-2-butenylene, 2-decyl-2-butenylene, 2-phenyl- 2-butenylene, 2-propylenephenyl-2-butenylene, 2-pentenylene, 4-ethyl-2-pentenylene, 4-propyl-2-pentenylene, 4-butyl-2-pentenylene, 4-hexyl-2-pentenylene, 4 Examples include polymers containing one or more structural units selected from -cyano-2-pentenylene, 3-methyl-2-pentenylene, 3-phenyl-2-pentenylene, 4-hydroxy-2-pentenylene, hexenylene, and the like.

  As polyimide, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′-tetracarboxydiphenyl ether dianhydride, 2,2 ′-[4 , 4′-di (dicarboxyphenyloxy) phenyl] propane dianhydride and the like, and polyimides composed of diamines such as oxydiamine, paraphenylenediamine, metaphenylenediamine, and benzophenonediamine.

  Examples of the polyamide include polyamide 6, polyamide 6,6, polyamide 6,10 and the like.

  Examples of the polyester include polyethylene terephthalate and polybutylene terephthalate.

  The anion group of the polyanion may be a functional group that can undergo chemical oxidation doping to the π-conjugated conductive polymer, but from the viewpoint of ease of production and stability, a monosubstituted sulfate group and a monosubstituted phosphate ester Group, phosphoric acid group, carboxy group, sulfo group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated conductive polymer, a sulfo group, a monosubstituted sulfate group, and a carboxy group are more preferable.

  Specific examples of polyanions include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly (2-acrylamido-2-methylpropane sulfonic acid), polyisoprene. Sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly (2-acrylamido-2-methylpropane carboxylic acid), polyisoprene carboxylic acid, polyacrylic acid, etc. Can be mentioned. These homopolymers may be used, or two or more types of copolymers may be used. Among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethyl sulfonic acid, and polyacrylic acid butyl sulfonic acid are preferable. These polyanions have high compatibility with the binder resin, and can further increase the conductivity of the obtained conductive layer.

  In the present invention, in addition to the polyanion, the following donor or acceptor dopant can be used as long as the π-conjugated conductive polymer can be oxidized and reduced.

  Donor dopants include alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, quaternary compounds such as tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium and dimethyldiethylammonium. An amine compound etc. are mentioned.

Examples of the acceptor dopant include halogen compounds such as Cl ₂ , Br ₂ , I ₂ , ICl, IBr, and IF, Lewis acids such as PF ₅ , AsF ₅ , SbF ₅ , BF ₅ , BCl ₅ , BBr ₅ , and SO ₃ , Tetracyanoethylene, tetracyanoethylene oxide, tetracyanobenzene, dichlorodicyanobenzoquinone, tetracyanoquinodimethane, tetracyanoazanaphthalene and other organic cyano compounds, proton acids, organometallic compounds, fullerenes, hydrogenated fullerenes, hydroxylated fullerenes, Carboxy oxide fullerene, sulfonated fullerene and the like can be used.

  Examples of the protonic acid include inorganic acids and organic acids. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, perchloric acid and the like. Examples of organic acids include organic carboxylic acids and organic sulfonic acids.

  As organic carboxylic acid, what contains 1 or 2 or more of carboxy groups in aliphatic, aromatic, cycloaliphatic, etc. can be used. For example, formic acid, acetic acid, oxalic acid, benzoic acid, phthalic acid, maleic acid, fumaric acid, malonic acid, tartaric acid, citric acid, lactic acid, succinic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, nitroacetic acid, And triphenylacetic acid.

  As the organic sulfonic acid, aliphatic, aromatic, cycloaliphatic or the like containing one or more sulfo groups or a polymer containing sulfo groups can be used.

  Examples of those containing one sulfo group include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-hexanesulfonic acid, 1-heptanesulfonic acid, 1-octanesulfonic acid, 1-nonanesulfonic acid, 1-decanesulfonic acid, 1-pentadecanesulfonic acid, 2-bromoethanesulfonic acid, 3-chloro-2-hydroxypropanesulfonic acid, trifluoromethanesulfonic acid, trifluoroethanesulfonic acid, colistin methanesulfone Acid, 2-acrylamido-2-methylpropanesulfonic acid, aminomethanesulfonic acid, 1-amino-2-naphthol-4-sulfonic acid, 2-amino-5-naphthol-7-sulfonic acid, 3-aminopropanesulfonic acid N-cyclohexyl-3-aminopropanesulfone Benzenesulfonic acid, alkylbenzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid, ethylbenzenesulfonic acid, propylbenzenesulfonic acid, butylbenzenesulfonic acid, pentylbenzenesulfonic acid, hexylbenzenesulfonic acid, heptylbenzenesulfonic acid, octylbenzene Sulfonic acid, nonylbenzenesulfonic acid, decylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, dipropylbenzenesulfonic acid, 4-aminobenzenesulfonic acid, o-aminobenzenesulfonic acid, m- Aminobenzenesulfonic acid, 4-amino-2-chlorotoluene-5-sulfonic acid, 4-amino-3-methylbenzene-1-sulfonic acid, 4-amino-5-methoxy-2-methylbenze Sulfonic acid, 2-amino-5-methylbenzene-1-sulfonic acid, 4-amino-2-methylbenzene-1-sulfonic acid, 5-amino-2-methylbenzene-1-sulfonic acid, 4-amino-3 -Methylbenzene-1-sulfonic acid, 4-acetamido-3-chlorobenzenesulfonic acid, 4-chloro-3-nitrobenzenesulfonic acid, p-chlorobenzenesulfonic acid, naphthalenesulfonic acid, methylnaphthalenesulfonic acid, propylnaphthalenesulfonic acid, butyl Naphthalenesulfonic acid, pentylnaphthalenesulfonic acid, 4-amino-1-naphthalenesulfonic acid, 8-chloronaphthalene-1-sulfonic acid, naphthalenesulfonic acid formalin polycondensate, melaminesulfonic acid formalin polycondensate, anthraquinonesulfonic acid, pyrene Examples include sulfonic acid It is done. These metal salts can also be used.

  Examples of those containing two or more sulfo groups include ethanedisulfonic acid, butanedisulfonic acid, pentanedisulfonic acid, decanedisulfonic acid, o-benzenedisulfonic acid, m-benzenedisulfonic acid, p-benzenedisulfonic acid, and toluenedisulfonic acid. Xylene disulfonic acid, chlorobenzene disulfonic acid, fluorobenzene disulfonic acid, dimethylbenzene disulfonic acid, diethylbenzene disulfonic acid, aniline-2,4-disulfonic acid, aniline-2,5-disulfonic acid, 3,4-dihydroxy-1,3 Benzene disulfonic acid, naphthalene disulfonic acid, methyl naphthalene disulfonic acid, ethyl naphthalene disulfonic acid, pentadecyl naphthalene disulfonic acid, 3-amino-5-hydroxy-2,7-naphthalene disulfonic acid, 1- Cetamide-8-hydroxy-3,6-naphthalenedisulfonic acid, 2-amino-1,4-benzenedisulfonic acid, 1-amino-3,8-naphthalenedisulfonic acid, 3-amino-1,5-naphthalenedisulfonic acid, 8-amino-1-naphthol-3,6-disulfonic acid, 4-amino-5-naphthol-2,7-disulfonic acid, 4-acetamido-4′-isothiocyanotostilbene-2,2′-disulfonic acid, Examples include 4-acetamido-4′-maleimidyl stilbene-2,2′-disulfonic acid, naphthalene trisulfonic acid, dinaphthylmethane disulfonic acid, anthraquinone disulfonic acid, and anthracene sulfonic acid. These metal salts can also be used.

  The hard coat layer of the present invention has at least one selected from the group consisting of polymethyl methacrylate-based fine particles, polystyrene-based fine particles, melamine polymer-based fine particles, and hydrophilic silica fine particles in order to improve curability. It may contain seed microparticles.

  The hard coat layer contains at least one kind of fine particles selected from the group consisting of polymethyl methacrylate-based fine particles, polystyrene-based fine particles, melamine polymer-based fine particles, and hydrophilic silica fine particles from the viewpoint of the object effect of the present invention. It is preferable.

  In order to reduce the liquid viscosity of the coating liquid from the leveling and handling properties at high speed application, it is better to lower the solid concentration, but the stability of the coating liquid in such a state and good dispersion The average particle diameter of at least one kind of fine particles selected from the group consisting of polymethyl methacrylate fine particles, polystyrene fine particles, melamine polymer fine particles, and hydrophilic silica fine particles is 5 nm to It is preferable to be within the range of 30 μm. More preferably, it is 10 nm-15 micrometers. The average particle diameter can be measured by, for example, a laser diffraction particle size distribution measuring apparatus.

  For the above reasons, the content of at least one kind of fine particles selected from the group consisting of polymethyl methacrylate-based fine particles, polystyrene-based fine particles, melamine polymer-based fine particles, and hydrophilic silica fine particles contained in the hard coat layer. Is preferably 0.01 to 500 parts by mass, more preferably 0.1 to 100 parts by mass, and particularly preferably 1 to 30 parts by mass with respect to 100 parts by mass of the resin solid content of the coating composition. .

  Here, as specific examples of the polymethyl methacrylate-based fine particles, the polystyrene-based fine particles, and the melamine polymer-based fine particles, the polymethyl methacrylate-based fine particles include, for example, Soken Chemicals; MX150, MX300, Nippon Shokubai; MA1004, MA1006, MA1010, Epostor MX (emulsion), grade; MX020W, MX030W, MX050W, MX100W), manufactured by Sekisui Plastics: MBX series (MBX-8, MBX12).

  Among the polymethyl methacrylate-based fine particles, fluorine-containing polymethyl methacrylate fine particles are preferable from the viewpoint of better exhibiting the hard coat property that is the effect of the present invention. Here, the fluorine-containing polymethyl methacrylate fine particles are formed from fine particles formed from monomers or polymers of fluorinated acrylate or fluorinated methacrylate, fluorine-containing acrylic acid, fluorine-containing methacrylic acid, fluoroacrylic acid or fluoromethacrylic acid. Fine particles, fine particles obtained by copolymerizing fluorine-containing methacrylic acid with a vinyl monomer in the presence of a crosslinking agent, and the like can be mentioned.

  Examples of the fluorine-containing methacrylic acid include fluorine-containing alkyl methacrylates such as trifluoroethyl methacrylate and tetrafluoropropyl methacrylate, and fluorine-containing alkyl acrylates such as perfluorooctylethyl acrylate.

  The vinyl monomer copolymerizable with fluorine-containing (meth) acrylic acid is not particularly limited as long as it has a vinyl group. Specifically, alkyl methacrylates such as methyl methacrylate and butyl methacrylate, and methyl acrylate. , Alkyl acrylates such as ethyl acrylate, and styrenes such as styrene and α-methylstyrene.

  The crosslinking agent used in the polymerization reaction is not particularly limited, but those having two or more unsaturated groups are preferably used. For example, bifunctional dimethacrylates such as ethylene glycol dimethacrylate and polyethylene glycol dimethacrylate are used. And trimethylolpropane trimethacrylate, divinylbenzene and the like. The copolymerization reaction may be either random copolymerization or block copolymerization.

  Specific examples of the compound include those described in JP-A No. 2000-169658. Examples of commercially available products include Nippon Paint: FS-701, Negami Kogyo: MF-0043, and the like. it can.

  Examples of the polystyrene fine particles include commercially available products such as those manufactured by Soken Kagaku; SX-130H, SX-200H, SX-350H), Sekisui Plastics, SBX series (SBX-6, SBX-8). In addition, polystyrene-based fine particles include fine particles obtained by crosslinking acrylic and styrene. Specifically, commercially available products such as FS-102, FS-401, FS-201, and MG-351 made by Nippon Paint are available. Can be mentioned.

  As the melamine polymer fine particles, Nippon Shokubai Co., Ltd .: benzoguanamine / melamine / formaldehyde condensate (trade name: eposter, grade; M30, trade name: eposter GP, grade: H40 to H110), Nippon Shokubai: melamine / formaldehyde condensate (Trade name: eposter, grade; S12, S6, S, SC4), manufactured by Nissan Chemical Industries: melamine resin / silica composite particles (trade name: Optobeads), and the like.

  On the other hand, examples of the hydrophilic silica fine particles include product names such as Nippon Aerosil, Aerosil 200, 200V, 300, Degussa, Aerosil OX50, TT600, Fuji Silysia Chemical, and Silicia 350.

  In the present invention, the above fine particles may be used alone or in combination of two or more. These fine particles may be added in any state such as powder or emulsion.

  Other fine particles include benzoguanamine-based fine particles, manufactured by Nippon Shokubai Co., Ltd .: benzoguanamine-formaldehyde condensate (trade name: eposter, grade; L15, M05, MS, SC25), etc. Examples thereof include dimic beads made and ethylene / methyl methacrylate copolymer.

  UV curable resin composition such as silicone resin powder, polystyrene resin powder, polycarbonate resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder Can also be added. Moreover, if necessary, the fine particles described in JP-A No. 2000-241807 may be further contained.

  The hard coat layer composition is preferably coated and dried and then irradiated with actinic rays such as ultraviolet rays and electron beams, or cured by heat treatment, but the irradiation time of actinic rays is 0.1 seconds to 5 minutes. It is preferably 0.1 to 10 seconds from the viewpoint of curing efficiency and work efficiency of the ultraviolet curable resin.

(Back coat layer)
In the present invention, it is preferable to provide a backcoat layer on the side opposite to the side on which the hard coat layer of the transparent film substrate such as a cellulose ester film is provided.

  The back coat layer is provided in order to correct curl caused by providing an active energy ray-curable resin layer or other layers. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. The backcoat layer is preferably applied also as an antiblocking layer. In this case, it is preferable that fine particles are added to the backcoat layer coating composition in order to provide an antiblocking function.

  As fine particles added to the back coat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxidation. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low haze, and silicon dioxide is particularly preferable.

  These fine particles are, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above, manufactured by Nippon Aerosil Co., Ltd.), Seahoster KE-P10, KE-P30, KE-P50. KE-P100, KE-P150, and KE-P250 (above, manufactured by Nippon Shokubai Co., Ltd.) can be used. Among these, particularly preferred are Sea Hoster KE-P30, KE-P50, and KE-P100.

  Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.), and can be used.

  Examples of the polymer fine particles include silicone resin, fluororesin, and acrylic resin. Silicone resin fine particles are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (above, manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

  The fine particles contained in the backcoat layer are 0.1 to 50% by weight, preferably 0.1 to 10% by weight, based on the binder. When the back coat layer is provided, the increase in haze is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.0 to 0.1%.

  Specifically, the back coat layer is formed by applying a composition containing a solvent for dissolving or swelling a cellulose ester film. The solvent to be used may include a solvent to be dissolved and / or a solvent to be swollen in addition to a solvent that does not dissolve, and a composition and coating in which these are mixed at an appropriate ratio depending on the curl degree of the transparent film and the type of resin. Do with quantity.

  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 film contained in such a mixed composition include dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, trichloroethylene, methylene chloride, ethylene chloride, tetrachloride. There are chloroethane, trichloroethane, chloroform and the like. Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, cyclohexanol, and hydrocarbons (toluene, xylene).

  These coating compositions are preferably applied to the surface of the transparent film with a wet film thickness of 1 to 100 μm using a gravure coater, dip coater, reverse coater, wire bar coater, die coater, spray coating, ink jet coating or the like. In particular, the thickness is preferably 5 to 30 μm. Examples of the resin used as the binder of the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.2-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin Rubber resins such as polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile resin, Examples thereof include, but are not limited to, 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.), Dianal 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 and the like (made by Mitsubishi Rayon Co., Ltd.) Methacrylic monomers and the commercially available various homopolymers and copolymers, etc. was prepared as a raw material, it is also possible to select a preferred mono from this appropriate.

  Particularly preferred are cellulosic resin layers such as diacetylcellulose, triacetylcellulose, cellulose acetate propionate, and cellulose acetate butyrate.

  The order of coating the backcoat layer may be before or after coating the active energy ray-curable resin layer of the cellulose ester film, but when the backcoat layer also serves as an antiblocking layer, it is desirable to coat it first. . Alternatively, the backcoat layer can be applied in two or more steps.

  When winding the hard coat film into a roll, the winding core is not particularly limited as long as it is a cylindrical core, but is preferably a hollow plastic core, and the plastic material is a heat resistant plastic that can withstand heat treatment temperatures. For example, resins such as phenol resin, xylene resin, melamine resin, polyester resin, and epoxy resin can be used. A thermosetting resin reinforced with a filler such as glass fiber is preferred.

  The number of windings on these winding cores is preferably 100 windings or more, more preferably 500 windings or more, and the winding thickness is preferably 5 cm or more.

  Thus, when heat-treating in the state which wound the long-winding hard coat film, it is preferable to rotate the roll, and the rotation is preferably a speed of 1 rotation or less per minute, and may be continuous. It may be intermittent rotation. Moreover, it is preferable to perform rewinding of the roll once or more during the heating period.

  In order to rotate the long hard coat film wound around the core during the heat treatment, it is preferable to provide a dedicated turntable in the heat treatment chamber.

  In the case of intermittent rotation, it is preferable that the stop time is within 10 hours, the stop position is preferably made uniform in the circumferential direction, and the stop time is within 10 minutes. More preferred. Most preferred is continuous rotation.

  As for the rotation speed in continuous rotation, the time required for one rotation is preferably 10 hours or less, and if it is early, it becomes a burden on the apparatus, so the range of 15 minutes to 2 hours is substantially preferable.

  In the case of a dedicated carriage having a rotation function, it is preferable that the optical film roll can be rotated during movement and storage. In this case, rotation is effective as a countermeasure against black bands that occur when the storage period is long. Function.

(Polarizer)
Next, a polarizing plate using the hard coat film of the present invention will be described.

  The polarizing plate can be produced by a general method. The back side of the hard coat film of the present invention is subjected to alkali saponification treatment, and the treated film is attached to at least one surface of a polarizing film produced by immersing and stretching in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. It is preferable to match. The film may be used for the other surface, or another polarizing plate protective film may be used. With respect to the hard coat film of the present invention, the polarizing plate protective film used on the other surface has an in-plane retardation (Ro) of 590 nm, a retardation of 20 to 70 nm, and a thickness direction retardation (Rt) of 100 to 400 nm. It is preferable that it is an optical compensation film (retardation film). These can be prepared, for example, by the methods described in JP-A No. 2002-71957 and Japanese Patent Application No. 2002-155395. Further, it is preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. Alternatively, a non-oriented film having an in-plane retardation (Ro) of 590 nm to 0 to 5 nm and a thickness direction retardation (Rt) of -20 to +20 nm is preferably used, and has excellent planarity and a stable viewing angle widening effect. Can be obtained.

  As a polarizing plate protective film used on the back side, as a commercially available cellulose ester film, KC8UX2MW, KC4UX, KC5UX, KC4UY, KC8UY, KC12UR, KC4UEW, KC8UCR-3, KC8UCR-4, KC8UCR-5, KC4FR-1, KC4F-1, -2 (manufactured by Konica Minolta Opto Co., Ltd.) and the like are preferably used.

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are ones in which iodine is dyed on a system film and ones in which a dichroic dye is dyed, but it is not limited to this. As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. A polarizing film having a thickness of 5 to 30 μm, preferably 8 to 15 μm, is preferably used. On the surface of the polarizing film, one side of the hard coat film of the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

(Image display device)
By incorporating a polarizing plate using the hard coat film of the present invention on the viewing surface side of the image display device, various image display devices with excellent visibility can be produced. The hard coat film of the present invention is a reflective type, transmissive type, transflective type LCD or TN type, STN type, OCB type, HAN type, VA type (PVA type, MVA type), IPS type, etc. Preferably used. Moreover, it is excellent in flatness and is preferably used for various display devices such as a plasma display, a field emission display, an organic EL display, an inorganic EL display, and electronic paper. In particular, an image display device having a large screen of 30 or more screens has an effect that there is little color unevenness and wavy unevenness, and eyes are not tired even during long-time viewing.

  Examples of the present invention will be described below, but the present invention is not limited thereto.

Example 1
A hard coat film according to the present invention was prepared. The hard coat layer of the hard coat film has a Martens hardness (HMs) value on the surface of the hard coat layer that varies depending on the composition of the resin composition for forming the hard coat layer. Various hard coat films according to the present invention and various hard coat films for comparison were prepared.

  First, the transparent film base material was produced by the solution casting film forming method using the following dope composition.

(Dope composition)
Cellulose triacetate (average degree of acetylation 61.0%) 100 parts by weight Triphenyl phosphate 8 parts by weight Ethylphthalyl ethyl glycolate 2 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 1 part by weight Tinuvin 171 (Ciba Specialty Chemicals) 1 part by weight Methylene chloride 430 parts by weight Methanol 90 parts by weight The above materials are put into a sealed container, kept at a temperature of 80 ° C. under pressure, and completely dissolved with stirring to obtain a dope composition. It was.

  Next, the dope composition was filtered, cooled and maintained at a temperature of 33 ° C., cast on a casting belt made of a stainless steel band from a casting die, a web was formed, and the film was peeled off by a peeling roll.

  Thereafter, the web was stretched 1.1 times in the width direction by a tenter, and then dried by a film drying apparatus having a large number of transport rolls arranged in a staggered manner as viewed from the side, and knurling with a height of 10 μm was formed at both ends. A transparent film substrate made of a transparent cellulose triacetate film was prepared by winding with a take-up roll. Here, the transparent film base material had a film thickness of 80 μm, a width of 1.5 m, and a length of 3000 m.

(Hard coat coating composition 1)
Dipentaerythritol hexaacrylate 35 parts by mass Dioxane glycol diacrylate 35 parts by mass Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene Glycol monomethyl ether 10 parts by weight Methyl acetate 45 parts by weight Acetone 10 parts by weight Methyl ethyl ketone 10 parts by weight Cyclohexanone 5 parts by weight Polyoxyethylene oleyl ether 0.5 parts by weight (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
Next, on the surface of the transparent film substrate made of the cellulose triacetate film (film thickness of 80 μm) prepared previously, the hard coat layer coating composition 1 is applied with a slit die, and the hot air temperature and wind speed are gradually increased. Finally, it was dried at a temperature of 85 ° C., and then irradiated with ultraviolet light of 0.15 J / cm ² with a high-pressure mercury lamp to provide a hard coat layer having a dry film thickness of 3.0 μm.

  Further, on the surface of the transparent film substrate opposite to the hard coat layer, the following back coat layer coating composition is die coated so as to have a wet film thickness of 14 μm, dried at a temperature of 80 ° C. A coat layer was provided.

(Coating composition for back coat layer)
Diacetyl cellulose 0.6 parts by weight Acetone 35 parts by weight Methyl ethyl ketone 35 parts by weight Methanol 35 parts by weight 2% methanol dispersion of silica particles 16 parts by weight Example 2
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 2 is used as the hard coat coating composition. There is in point.

(Hard coat coating composition 2)
Pentaerythritol tetraacrylate 25 parts by weight Pentaerythritol triacrylate 25 parts by weight Dipentaerythritol hexaacrylate 30 parts by weight Dioxane glycol diacrylate 20 parts by weight Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by weight Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene glycol monomethyl ether 15 parts by mass Methyl acetate 40 parts by mass Methyl ethyl ketone 40 parts by mass Cyclohexanone 5 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation) )
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 2 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Example 3
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 3 is used as the hard coat coating composition. It is in the point.

(Hard coat coating composition 3)
Dipentaerythritol hexaacrylate 35 parts by mass Dioxane glycol diacrylate 30 parts by mass Zinc antimonate sol-methanol dispersion 15 parts by mass (CX-Z610M-F2: manufactured by Nissan Chemical Industries, Ltd.)
Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene glycol monomethyl ether 30 parts by mass Isopropyl alcohol 45 parts by mass Acetone 10 parts by mass Methyl ethyl ketone 10 parts by mass Cyclohexanone 5 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 3 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Example 4
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 4 is used as the hard coat coating composition. It is in the point.

(Hard coat coating composition 4)
Pentaerythritol tetraacrylate 25 parts by mass Pentaerythritol triacrylate 25 parts by mass Dipentaerythritol hexaacrylate 30 parts by mass Dioxane glycol diacrylate 20 parts by mass Zinc antimonate sol methanol dispersion 20 parts by mass (CX-Z610M-F2: Nissan Chemical Industries, Ltd.) Made)
Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene glycol monomethyl ether 30 parts by mass Isopropyl alcohol 50 parts by mass Methyl ethyl ketone 50 parts by mass 0.5 parts by mass of polyoxyethylene oleyl ether (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 4 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Example 5
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 5 is used as the hard coat coating composition. It is in the point.

(Hard coat coating composition 5)
Dipentaerythritol hexaacrylate 35 parts by weight Dioxane glycol diacrylate 32 parts by weight Polyaniline-containing coating agent 22 parts by weight (ORMECOND1000: ORMECON CHEMIE Gmbh & Co.KG)
Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene glycol monomethyl ether 75 parts by mass N-methyl-2-pyrrolidone 50 parts by mass Isopropyl alcohol 75 parts by mass Methyl ethyl ketone 10 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 5 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Example 6
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 6 is used as the hard coat coating composition. There is in point.

(Hard coat coating composition 6)
Pentaerythritol tetraacrylate 25 parts by mass Pentaerythritol triacrylate 25 parts by mass Dipentaerythritol hexaacrylate 30 parts by mass Dioxane glycol diacrylate 20 parts by mass Tetracyanotetraazanaphthalene-doped polypyrrole solution 18 parts by mass (SSPY: manufactured by TA Chemical)
Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Propylene glycol monomethyl ether 25 parts by mass N-methyl-2-pyrrolidone 50 parts by mass Isopropyl alcohol 50 parts by mass Methyl ethyl ketone 15 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 6 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Example 7
The hard coat film of the present invention is produced in the same manner as in Example 1, except that the following hard coat coating composition 7 is used as the hard coat coating composition. There is in point.

(Hard coat coating composition 7)
Dipentaerythritol hexaacrylate 35 parts by weight Pentaerythritol tetraacrylate 35 parts by weight Dioxane glycol diacrylate 30 parts by weight Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by weight Propylene glycol monomethyl ether 10 parts by weight Methyl acetate 40 parts by weight Methyl ethyl ketone 15 parts by mass Cyclohexanone 5 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition 7 for hard-coat layers was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Comparative Example 1
For the comparative example, a comparative hard coat film is produced in the same manner as in the case of Example 1 described above. The difference from the case of Example 1 is that the hard coat coating composition described below is used. Coating composition—Comparison 1 was used.

(Hard Coat Coating Composition—Comparison 1)
Ditrimethylolpropane triacrylate 50 parts by weight Dioxane glycol diacrylate 25 parts by weight Ethoxylated-methyl-1.3propanediol diacrylate 25 parts by weight Photopolymerization initiator 1 (Irgacure 184: manufactured by Ciba Japan) 3 parts by weight Photopolymerization initiator 2 (Irgacure 907: Ciba Japan Co., Ltd.) 4 parts by mass Propylene glycol monomethyl ether 30 parts by mass Methyl acetate 40 parts by mass Acetone 15 parts by mass Methyl ethyl ketone 10 parts by mass Cyclohexanone 5 parts by mass Polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: Manufactured by Kao)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition for hard-coat layers-Comparison-1 was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Comparative Example 2
For the comparative example, a comparative hard coat film is produced in the same manner as in the case of Example 1 described above. The difference from the case of Example 1 is that the hard coat coating composition described below is used. Coating composition—Comparison 2 was used.

(Hard Coat Coating Composition—Comparison 2)
Trimethylolpropane triacrylate 20 parts by mass Dipentaerythritol hexaacrylate 60 parts by mass Ethoxylated-methyl-1.3propanediol diacrylate 20 parts by mass Photopolymerization initiator 1 (Irgacure 184, manufactured by Ciba Japan) 6 parts by mass Photopolymerization initiator 2 (Irgacure 907: manufactured by Ciba Japan) 4 parts by mass Colloidal silica methyl ethyl ketone dispersion 12 parts by mass (MEK-ST: manufactured by Nissan Chemical Industries, Ltd.)
Propylene glycol monomethyl ether 15 parts by weight Methyl acetate 45 parts by weight Methyl ethyl ketone 25 parts by weight Cyclohexanone 10 parts by weight Polyoxyethylene oleyl ether 0.5 parts by weight (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition for hard-coat layers-the comparison 2 was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Comparative Example 3
For the comparative example, a comparative hard coat film is produced in the same manner as in the case of Example 1 described above. The difference from the case of Example 1 is that the hard coat coating composition described below is used. Coating composition—Comparison 3 was used.

(Hard Coat Coating Composition—Comparison 3)
Pentaerythritol tetraacrylate 55 parts by weight Isophorone diisocyanate 25 parts by weight Hydroxyethyl methacrylate 10 parts by weight Zirconium oxide methyl ethyl ketone dispersion 5 parts by weight Photopolymerization initiator 3 (Darocur 1173: manufactured by Ciba Japan) 5 parts by weight Propylene glycol monomethyl ether 30 parts by weight Ethyl acetate 45 parts by weight Acetone 10 parts by weight Methyl ethyl ketone 10 parts by weight Cyclohexanone 5 parts by weight Polyoxyethylene oleyl ether 0.5 parts by weight (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluororesin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition for hard-coat layers-Comparison-3 was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

Comparative Example 4
For the comparative example, a comparative hard coat film is produced in the same manner as in the case of Example 1 described above. The difference from the case of Example 1 is that the hard coat coating composition described below is used. Coating composition—Comparison 4 was used.

(Hard Coat Coating Composition—Comparison 4)
Trimethylolpropane triacrylate 25 parts by weight Dipentaerythritol hexaacrylate 25 parts by weight Isophorone diisocyanate 10 parts by weight Hydroxyethyl methacrylate 10 parts by weight Titanium oxide methyl ethyl ketone dispersion 5 parts by weight Photopolymerization initiator 3 (Darocur 1173: manufactured by Ciba Japan) 5 Parts by mass propylene glycol monomethyl ether 5 parts by mass isopropanol 30 parts by mass methyl ethyl ketone 50 parts by mass cyclohexanone 5 parts by mass polyoxyethylene oleyl ether 0.5 parts by mass (Emulgen 404: manufactured by Kao Corporation)
2 parts by mass of polysiloxane-fluorine resin copolymer (ZX-007C: manufactured by Fuji Kasei Kogyo Co., Ltd.)
(Preparation of hard coat layer)
And like the case of the said Example 1, the said coating composition for hard-coat layers-Comparison-4 was apply | coated to the surface of the transparent film base material which consists of a cellulose triacetate film, and the hard-coat layer was provided.

  In addition, a back coat layer was provided on the surface of the transparent film substrate opposite to the hard coat layer in the same manner as in Example 1 above.

(Measurement of Martens hardness)
About each hard coat film of Examples 1-7 produced as mentioned above and Comparative Examples 1-4, the Martens hardness (HMs) of the hard coat layer surface was measured using the micro hardness meter.

  That is, for each of the above hard coat films, each hard coat using a Vickers indenter and a micro hardness tester (trade name, DUH-212, manufactured by Shimadzu Corporation) using a triangular pyramid indenter whose angle between ridges is 115 degrees. A load test force-indentation depth curve was created when the indenter was pushed down to the thickness of about 1/10 of the thickness of the hard coat layer on the film surface. And the inclination that the indentation depth from the 50% value to the 90% value of the maximum load test force (Fmax) obtained from the load test force-indentation depth curve for each hard coat film is proportional to the square root of the load test force. From (m), the value of the Martens hardness (HMs) of the hard coat layer surface defined by the following formula was calculated. The obtained results are shown in Table 1 below.

HMs = 1 / (26.43 m ² )
(Measurement of refractive index)
About each hard coat film of Examples 1-7 produced as mentioned above, and Comparative Examples 1-4, the refractive index of the hard coat layer of each film was measured with a spectrophotometer (trade name, U-4000 type, Hitachi). It was calculated | required from the measurement result of the spectral reflectance of a manufacturing company make.

  In addition, each hard coat film sample of Examples 1 to 7 and Comparative Examples 1 to 4 was subjected to a light absorption treatment with a black spray after the back surface of the measurement surface was roughened, Reflection was prevented, and the reflectance in the visible light region (400 nm to 700 nm) was measured under the regular reflection condition at 5 degrees. The obtained results are shown in Table 1 below.

(Evaluation of hard coat film)
About each hard coat film of Examples 1-7 and Comparative Examples 1-4 produced as described above, solvent resistance (solvent penetration resistance), antifouling property, crack resistance, occurrence of foreign matter failure, application Unevenness and scratch resistance were evaluated, and the obtained results are shown in Table 1 below.

(Solvent resistance)
The surfaces of the hard coat film samples of Examples 1 to 7 and Comparative Examples 1 to 4 were strongly rubbed 10 times with a woven fabric impregnated with ethanol (trade name, Bencott, manufactured by Asahi Kasei Co., Ltd.) and then visually observed. Evaluation was performed according to the following criteria.

○: No change △: Some peel slightly ×: Peel (antifouling)
The surface of each hard coat film sample was contaminated with an oily red marking pen (magic ink, oily, very thick, manufactured by Teranishi Chemical Co., Ltd.), 18 hours later, wiped with gauze dipped in petroleum benzine, and then ethanol Washed with, lightly wiped with dry gauze, the state of contamination was observed, and the antifouling property was evaluated according to the following criteria.

◎: No trace of contamination is observed and the marking pen ink is repelled very well ○: No trace of contamination is observed △: Trace of contamination is faintly observed X: Trace of contamination is clearly recognized (Crack resistance)
Samples of each hard coat film are stored using a cycle thermo tester for 24 hours under conditions of a temperature of 80 ° C. and a humidity of 20% RH, and under conditions of a temperature of 80 ° C. and a humidity of 80% RH for 24 hours, respectively. This was repeated for 17 days. Next, a sample of each hard coat film after 17 days was wound around a round bar having a diameter of 5 mm and a diameter of 10 mm, and the occurrence of cracks was observed and evaluated according to the following criteria. In addition, it shows that the tolerance of a crack is so weak that the crack has generate | occur | produced on the conditions with a large diameter of a round bar.

◎: No cracks occurred when wound on a round bar of any diameter ○: When wound on a round bar with a diameter of 5 mm, there was a trace of winding △: When wound on a round bar with a diameter of 5 mm A crack occurred when wound on a round bar with a diameter of 10 mm (occurrence of foreign matter failure)
For each hard coat film sample, the number of foreign matter failures of 50 μm or more per 10 cm 2 of the film was counted visually and with an optical microscope, and converted to the number per 1 m ² . The occurrence of foreign object failure was evaluated according to the following criteria.

A: A foreign matter failure with a size of 50 μm or more observed visually and with an optical microscope
Less than 3 / m ² ○: Foreign matter failure of 50 μm or larger observed visually and with an optical microscope
3 / m ² or more and less than 5 / m ² Δ: Foreign matter failure having a size of 50 μm or more observed visually and with an optical microscope
5 pieces / m ² or more and less than 10 pieces / m ² ×: foreign matter failure having a size of 50 μm or more observed visually and with an optical microscope
10 pieces / m ² or more (film coating unevenness)
A double-sided tape without a heat-resistant substrate (made by HORICO) is bonded to a black acrylic board (trade name, Clarex, made by Nitto Resin Co., Ltd.), and each hard coat film sample is coated with a hard coat layer coated surface. Are placed on a desk 80 cm high from the floor, and a daylight direct fluorescent lamp (FLR40S • D / MX: Matsushita Electric) is placed on the ceiling 3 m high from the floor. (Made by Sangyo Co., Ltd.) When the evaluator is in front of the hard coat film sample under a fluorescent lamp with 40W × 2 as a set, the fluorescent lamp comes to the ceiling from the evaluator's head toward the rear. I did it. The film sample was tilted by 25 ° from the vertical direction with respect to the desk so that the fluorescent lamp was reflected. At that time, the coating unevenness of the film sample was evaluated according to the following criteria.

○: Color unevenness due to application is not observed at all on the film sample. Δ: Color unevenness due to application is slightly observed on the film sample. ×: Color unevenness due to application is observed severely on the film sample (abrasion resistance).
On each hard coat film sample, steel wool (SW) (trade name Bonstar # 0000, manufactured by Nippon Steel Wool Co., Ltd.) is placed in an environment of temperature 25 ° C. and humidity 60% RH, and a load of 250 g / cm ² is applied. The number of scratches per 1 cm when 10 reciprocations were applied was measured. Note that the number of scratches is measured at the point where the number of scratches is the largest among the portions to which a load is applied.

  Scratch resistance is 10 / cm or less, but there is no practical problem, but 5 / cm or less is preferable, and 3 / cm or less is more preferable.

(Preparation of polarizing film)
Next, in order to produce a polarizing plate and a liquid crystal display panel using the same using the hard coat films of Examples 1 to 7 and Comparative Examples 1 to 4 according to the present invention, first, a polarizing film is produced. did.

  In the production of the polarizing film, a polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature 110 ° C., stretch ratio 5 times). This was immersed in an aqueous solution consisting of 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 g of potassium iodide, 7.5 g of boric acid, and 100 g of water. This was washed with water and dried to obtain a polarizing film.

(Preparation of polarizing plate)
Then, according to the following steps 1 to 5, the polarizing film, each hard coat film produced in Examples 1 to 7 and Comparative Examples 1 to 4, and a cellulose ester film having a commercially available retardation (trade name, Konica Minolta Tac Co., Ltd., manufactured by Konica Minolta Opto Co., Ltd.) was bonded so that the hard coat layer was on the outside, and a polarizing plate was produced.

  Step 1: The hard coat films of Examples 1 to 7 and Comparative Examples 1 to 4 and the cellulose ester film were immersed in a 2 mol / L sodium hydroxide solution at a temperature of 50 ° C. for 60 seconds, and then washed with water. It dried and the hard coat film and cellulose-ester film which saponified the side bonded with a polarizing film were obtained.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Gently wipe off the excess adhesive adhering to the polarizing film in Step 2, laminating the cellulose ester film saponified in Step 1 on one side of this polarizing film, and then on the other side of the polarizing film The hard coat film saponified in step 1 was laminated so that the hard coat layer was on the outside.

Step 4: pressure 20-30 N / cm ² the polarizing film arranged in the step 3, the conveying speed was pasted at approximately 2m / min.

  Step 5: The polarizing film, the cellulose ester film, and the laminated film of the hard coat film prepared in Step 4 were dried in a drier at a temperature of 80 ° C. for 2 minutes to prepare a polarizing plate.

(Production of liquid crystal display panel)
Next, the polarizing plate on the outermost surface of a commercially available liquid crystal display panel (manufactured by NEC, color liquid crystal display, MultiSync, LCD1525J: model name, LA-1529HM) was carefully peeled off. The polarizing plates produced using the hard coat films of ˜4 were each bonded to produce various liquid crystal display panels, and the hard coat properties of the obtained liquid crystal display panels were evaluated.

(LCD panel evaluation)
About the various liquid crystal panels obtained as described above, the coating unevenness visibility was evaluated as follows. The obtained results are shown in Table 1 below.

(Application unevenness visibility / display panel)
A polarizing plate prepared by using the hard coat films of Examples 1 to 7 described above and the hard plates of Comparative Examples 1 to 4 were carefully peeled off the polarizing plate on the outermost surface of a commercially available liquid crystal display panel (VA type). Each polarizing plate produced using a coat film was attached.

  The various liquid crystal display panels obtained as described above are placed on a desk 80 cm high from the floor, and a daylight direct fluorescent lamp (trade name: FLR40S · D is placed on the ceiling 3 m high from the floor. / M-X, manufactured by Matsushita Electric Industrial Co., Ltd.) One set of 40W × 2 was arranged in 10 sets at 1.5 m intervals.

  Here, when the evaluator is in front of the display surface of the liquid crystal panel, the fluorescent lamp is arranged so that the fluorescent lamp comes to the ceiling from the evaluator's overhead to the rear. The liquid crystal panel was tilted 25 ° from the vertical direction with respect to the desk so that a fluorescent lamp was reflected, and the coating unevenness of the liquid crystal display panel sample at that time was evaluated according to the following criteria.

○: Color unevenness due to application is not observed at all on the liquid crystal display panel sample. Δ: Color unevenness due to application is slightly observed on the liquid crystal display panel sample. ×: Color unevenness due to application is observed severely on the liquid crystal display panel sample. Ru

  As is clear from the results of Table 1 above, the hard coat films of Examples 1 to 7 according to the present invention are excellent in solvent resistance. For example, even when a coating liquid having another function is applied to the upper layer, The solvent contained in the coating solution does not penetrate into the lower layer and is excellent in coating property. In addition, the hard coat films of Examples 1 to 7 according to the present invention have high physical strength (crack resistance and scratch resistance), and can reduce foreign matter failures and coating unevenness, thereby preventing soiling of the hard coat film. It was possible to greatly increase the property. And, the larger the production area of the hard coat film, the higher the probability of occurrence of foreign matter failure and uneven coating due to cracks in the hard coat layer. According to the present invention, the surface of the hard coat layer was pushed with a microhardness meter. When the Martens hardness (HMs) on the surface of the hard coat layer was regulated within a predetermined range, the yield could be reduced even when the production area was large, and the film productivity could be improved.

  Furthermore, according to the liquid crystal panel which bonded the polarizing plate produced using the hard coat film of Examples 1-7 by this invention, respectively, there was no coating nonuniformity and it was excellent in visibility.

  On the other hand, the hard coat films of Comparative Examples 1 to 4 are inferior in solvent resistance because the Martens hardness (HMs) of the hard coat layer surface is outside the scope of the present invention. It was inferior in nature. Moreover, since the hard coat films of Comparative Examples 1 to 4 have inferior physical strength (crack resistance / abrasion resistance), foreign matter failure and coating unevenness cannot be reduced. If the production area of the hard coat film increases, the probability of occurrence of foreign matter failure and coating unevenness due to cracks in the hard coat layer increases, resulting in a further decrease in yield and film productivity. There was a risk of lowering.

  Moreover, according to the liquid crystal panel which bonded the polarizing plate produced using the hard coat film of Comparative Examples 1-4, the application | coating nonuniformity generate | occur | produced and it was inferior to visibility.

Claims (5)

A hard coat film in which a hard coat layer is laminated on a transparent resin film substrate, and the hard coat layer surface has a Martens hardness (HMs) of 200 N / mm ² or more and 300 N / mm ² or less, and a hard coat A hard coat film, wherein the refractive index of the layer is 1.60 or less.
Here, the Martens hardness (HMs) on the surface of the hard coat layer is a micro hardness meter (DUH-211: manufactured by Shimadzu Corporation) using a Vickers indenter and a triangular pyramid indenter whose angle between ridges is 115 degrees. The maximum load test obtained from the load test force-indentation depth curve in the load test force-indentation depth curve when the indenter is pushed down to the thickness of about 1/10 of the thickness of the hard coat layer. The indentation depth from the 50% value to the 90% value of the force (Fmax) is a value defined by the following formula from the slope (m) in proportion to the square root of the load test force.
HMs = 1 / (26.43 m ² )   The hard coat film according to claim 1, wherein the hard coat layer has conductivity.   A polarizing plate, wherein the hard coat film according to claim 1 or 2 is bonded to at least one of both surfaces of a polarizer.   A display device using the hard coat film according to claim 1.   A display device comprising the polarizing plate according to claim 3.