KR20120123200A - Resin composition, optical film and liquid crystal display device - Google Patents

Abstract

PURPOSE: A resin composition is provided to effectively restrain insertion of bubbles and non-uniformity of haze generable on an optical film, which is obtained by spreading the resin composition on the substrate film. CONSTITUTION: A resin composition comprises a transparent resin or a mixture comprising a resin component and solvent forming the transparent resin, and a transparent particle. A surface tension of the mixture at 25 °C is 18-35 mN/m. The transparent particle has a minimum value of methanol concentration of aqueous methanol solution. The minimum value is 1.0-15.0 weight% at 25 °C. The optical film comprises a substrate film, and an anti-glare layer formed by the resin composition laminated on the substrate film. [Reference numerals] (20) Light source; (30) Detector; (40) Stirrer; (60) Pump

Description

RESIN COMPOSITION, OPTICAL FILM AND LIQUID CRYSTAL DISPLAY DEVICE}

This invention relates to the resin composition containing translucent microparticles | fine-particles useful for an optical film use. Moreover, this invention relates to the optical film provided with the resin layer (antiglare layer etc.) formed from the said resin composition, and the liquid crystal display device using the same.

In image display apparatuses, such as a liquid crystal display device, in order to prevent external light from shining in, optical films, such as an anti-glare film, may be arrange | positioned on the visual recognition side surface. Such an anti-glare film is produced by, for example, coating a resin composition (coating solution) containing translucent fine particles (beads) on a base film to form a resin layer having surface irregularities based on the translucent fine particles (for example, Japanese patent). Publication 2010-079099).

In the conventional optical film which formed the resin layer by coating the resin composition in which the translucent microparticles were mixed-dispersed on the base film, since the dispersibility of the translucent microparticles | fine-particles in a resin composition is not favorable, the haze nonuniformity is obtained. This may occur, or air bubbles may occur in the resin layer to impair appearance quality. Nonuniformity of such a haze and generation | occurrence | production of a bubble reduce the product yield of an optical film.

An object of the present invention is to provide a light-transmitting fine particle-containing resin composition capable of effectively suppressing nonuniformity and bubble mixing of haze that may occur in an optical film obtained by coating on a base film. Moreover, another object of this invention is to provide the optical film in which the nonuniformity of haze and the generation | occurrence | production of foam | bubble were formed using this resin composition, and the liquid crystal display device provided with this.

The present invention includes the following.

[1] A resin composition comprising a light-transmissive resin or a mixture containing a resin component and a solvent forming the same, and light-transmitting fine particles,

The surface tension at 25 degrees C of the said mixture is 18 mN / m or more and 35 mN / m or less,

The said light-transmitting microparticles | fine-particles have a lower limit of the methanol concentration of the methanol solution which can be suspended, and this lower limit is 1.0 weight% or more and less than 15.0 weight% in 25 degreeC.

[2] The resin composition according to [1], in which the light-transmitting fine particles are made of any polymer selected from the group consisting of polystyrene, poly (meth) acrylate and polystyrene-poly (meth) acrylate copolymer.

[3] The resin composition according to [1] or [2], wherein the content of the light-transmitting fine particles is 25 parts by weight or more and less than 50 parts by weight with respect to 100 parts by weight of the light-transmissive resin or the resin component forming the same.

[4] The resin composition according to any one of [1] to [3], wherein the weight average particle diameter of the light-transmitting fine particles is 5 µm or more and 10 µm or less.

[5] An optical film having a base film and an antiglare layer laminated on the base film and formed of the resin composition according to any one of [1] to [4].

[6] A liquid crystal display device comprising a backlight device, light deflection means, a first polarizing plate, a liquid crystal cell, a second polarizing plate, and the optical film described in [5] in this order.

[7] The optical deflecting means has two prism films each having a plurality of linear prisms on a surface of the first polarizing plate,

One prism film is arrange | positioned so that the ridge direction of the linear prism may become substantially parallel to the transmission axis of the said 1st polarizing plate, and the other prism film has the ridge direction of the linear prism at the transmission axis of a said 2nd polarizing plate The liquid crystal display device as described in [6] arrange | positioned so that it may become substantially parallel.

[8] The liquid crystal display according to [6] or [7], further comprising a light diffusing means between the backlight device and the light deflecting means.

According to this invention, since the dispersibility of the translucent microparticles | fine-particles in a resin composition is favorable, the optical film in which generation | occurrence | production of the bubble in the resin layer formed from the nonuniformity of a haze and the resin composition can be provided. The optical film of this invention is excellent in the homogeneity of a haze, and also excellent in appearance quality.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the apparatus system for measuring the lower limit of the methanol concentration of the methanol aqueous solution which can suspend translucent microparticles | fine-particles.
FIG. 2 is a graph showing the relationship between the methanol concentration obtained using the apparatus system shown in FIG. 1 and the transmittance of laser light.
It is a schematic sectional drawing which shows a preferable example of the optical film of this invention.
It is a schematic sectional drawing which shows another preferable example of the optical film of this invention.
It is a schematic sectional drawing which shows another preferable example of the optical film of this invention.
It is a schematic sectional drawing which shows a preferable example of the anti-glare polarizing plate of this invention.
It is a schematic sectional drawing which shows a preferable example of the liquid crystal display device of this invention.
It is a schematic perspective view for demonstrating the relationship of the ridge direction of the linear prism which a prism film has, and the transmission axis direction of a polarizing plate.
9 is a schematic cross-sectional view showing another preferred example of the liquid crystal display of the present invention.
10 is a schematic view of a liquid crystal display according to the present invention, FIG. 10 (a) is a front view of the liquid crystal display according to the present invention, and FIG. 10 (b) is a plane 4b of FIG. It is the figure seen from the direction.

<Resin composition>

The resin composition of this invention is a resin composition containing translucent microparticles | fine-particles suitable for forming the resin layer (resin coating layer) which various optical films can comprise, Specifically, a translucent resin or the resin component and solvent which form this It consists of a mixture containing at least and translucent microparticles. The resin composition of this invention may further contain other components, such as a photoinitiator, a leveling agent, a dispersing agent, an antistatic agent, and an antifouling agent. The resin composition of this invention is excellent in the dispersibility of translucent microparticles | fine-particles, The optical film which has a resin layer formed by coating this on a base film is excellent in the homogeneity of haze, and the bubble generation in a resin layer is suppressed effectively, There is excellent appearance quality.

(1) resin

As a translucent resin contained in a resin composition or the resin component which forms this, for example, active energy-ray-curable resins, such as an ultraviolet curable resin and an electron beam curable resin, heat transmitting resin, such as a thermoplastic resin, a resin component which forms a translucent resin, and heat Curable resin, a metal alkoxide, etc. are mentioned. Especially, since the resin layer which showed high hardness by coating and hardening of a resin composition, and provided with high abrasion resistance as an optical film provided in the liquid crystal display device surface can be formed, active-energy-ray-curable resin is suitable.

As a thermoplastic resin, Cellulose derivatives, such as acetyl cellulose, nitrocellulose, acetylbutyl cellulose, ethyl cellulose, and methyl cellulose; Vinyl resins such as vinyl acetate and its copolymers, vinyl chloride and its copolymers, vinylidene chloride and its copolymers; Acetal resins such as polyvinyl formal and polyvinyl butyral; (Meth) acrylic resins such as acrylic resins and copolymers thereof, methacryl resins and copolymers thereof; Polystyrene resin; Polyamide based resin; Polyester-based resin; Polycarbonate resin etc. are mentioned.

Active-energy-ray-curable resin may be a thing containing a polyfunctional (meth) acrylate compound. A polyfunctional (meth) acrylate compound is a compound which has at least 2 (meth) acryloyloxy group in a molecule | numerator.

Specific examples of the polyfunctional (meth) acrylate compound include, for example, an ester compound of a polyhydric alcohol and (meth) acrylic acid, a urethane (meth) acrylate compound, a polyester (meth) acrylate compound, and an epoxy (meth) acryl It is a polyfunctional polymeric compound containing two or more (meth) acryloyl groups, such as a late compound.

Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, polypropylene glycol, propanediol, butanediol, and pentanediol. Dihydric alcohols such as hexanediol, neopentylglycol, 2-ethyl-1,3-hexanediol, 2,2'-thiodieethanol and 1,4-cyclohexanedimethanol; And trihydric or higher alcohols such as trimethylolpropane, glycerol, pentaerythritol, diglycerol, dipentaerythritol, and ditrimethylolpropane.

Specific examples of esterified products of polyhydric alcohols with (meth) acrylic acid include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neo Pentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, 1,6-hexanedioldi (meth) Acrylate, tetramethylol methane tetra (meth) acrylate, pentaglycerol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerin tri (meth) acrylate, di Pentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) There may be mentioned a methacrylate.

As a urethane (meth) acrylate compound, the urethane-ized reaction material of the isocyanate which has several isocyanate groups in one molecule, and the (meth) acrylic acid derivative which has a hydroxyl group is mentioned. As an organic isocyanate which has several isocyanate groups in 1 molecule, 1, such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, dicyclohexyl methane diisocyanate, etc. Organic isocyanates having two isocyanate groups in the molecule; And organic isocyanates having three isocyanate groups in one molecule in which isocyanurate-modified, adduct-modified, or biuret-modified organic isocyanate having two isocyanate groups in one molecule. As a (meth) acrylic-acid derivative which has a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth ) Acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and pentaerythritol triacrylate are mentioned.

As a polyester (meth) acrylate compound, polyester (meth) acrylate obtained by making a hydroxyl-containing polyester and (meth) acrylic acid react is preferable. The hydroxyl group containing polyester used preferably is the hydroxyl group containing polyester obtained by esterification of the compound which has a polyhydric alcohol, carboxylic acid, and some carboxyl group, and / or its anhydride. As a polyhydric alcohol, the same thing as the compound mentioned above can be illustrated. In addition to polyhydric alcohols, phenols such as bisphenol A can be used. Formic acid, acetic acid, butylcarboxylic acid, benzoic acid, etc. are mentioned as carboxylic acid. Examples of the compound having a plurality of carboxyl groups and / or anhydrides thereof include maleic acid, phthalic acid, fumaric acid, itaconic acid, adipic acid, terephthalic acid, maleic anhydride, phthalic anhydride, trimellitic acid and cyclohexanedicarboxylic anhydride. Can be.

Among the above-mentioned multifunctional (meth) acrylate compounds, hexanediol di (meth) acrylate, neopentylglycol di (meth) acrylate, diethylene glycol from the point of the strength improvement and the availability of hardened | cured material (film). Ester compounds such as di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate and dipentaerythritol hexa (meth) acrylate; Adducts of hexamethylene diisocyanate and 2-hydroxyethyl (meth) acrylate; Adducts of isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate; Adducts of tolylene diisocyanate and 2-hydroxyethyl (meth) acrylate; Adduct of adduct modified isophorone diisocyanate and 2-hydroxyethyl (meth) acrylate; And an adduct of biuret-modified isophorone diisocyanate with 2-hydroxyethyl (meth) acrylate. Moreover, it is preferable that active energy ray hardening type resin contains a urethane (meth) acrylate compound. A polyfunctional (meth) acrylate compound can be used individually or in combination of 2 or more types, respectively.

The active energy ray-curable resin may contain a monofunctional (meth) acrylate compound in addition to the polyfunctional (meth) acrylate compound described above. As a monofunctional (meth) acrylate compound, For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxy Cipropyl (meth) acrylate, glycidyl (meth) acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, 2- Ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, acetyl (meth) acrylate, benzyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) Acrylate, ethylcarbitol (meth) acrylate, phenoxy (meth) ) Acrylate, ethylene oxide modified phenoxy (meth) acrylate, propylene oxide (meth) acrylate, nonylphenol (meth) acrylate, ethylene oxide modified (meth) acrylate, propylene oxide modified nonylphenol (meth) acrylate Methoxydiethylene glycol (meth) acrylate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, dimethylaminoethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and the like (Meth) acrylates are mentioned. A monofunctional (meth) acrylate compound can be used individually or in combination of 2 or more types, respectively.

The active energy ray-curable resin may contain a polymerizable oligomer. By containing a polymerizable oligomer, the hardness of a resin layer can be adjusted. The polymerizable oligomer may be, for example, the polyfunctional (meth) acrylate compound, that is, an ester compound of a polyhydric alcohol and (meth) acrylic acid, a urethane (meth) acrylate compound, a polyester (meth) acrylate compound or an epoxy ( Oligomers such as dimers, trimers, etc., such as meth) acrylates.

Moreover, as another polymerizable oligomer, the urethane (meth) acrylate oligomer obtained by reaction of the polyisocyanate which has at least 2 isocyanate group in a molecule | numerator, and the polyhydric alcohol which has at least 1 (meth) acryloyloxy group is mentioned. Can be. Examples of the polyisocyanate include polymers of hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate and the like. As a polyhydric alcohol which has at least 1 (meth) acryloyloxy group, it is a hydroxyl group containing (meth) acrylic acid ester obtained by esterification reaction of a polyhydric alcohol and (meth) acrylic acid, As a polyhydric alcohol, For example, 1, 3- butanediol And 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, trimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, and the like. . In this polyhydric alcohol having at least one (meth) acryloyloxy group, a part of the alcoholic hydroxyl group of the polyhydric alcohol is esterified with (meth) acrylic acid, and the alcoholic hydroxyl group remains in the molecule.

Moreover, as an example of another polymerizable oligomer, the polyester (meth) acryl obtained by reaction of the compound which has a some carboxyl group, and / or its anhydride, and the polyhydric alcohol which has at least 1 (meth) acryloyloxy group And late oligomers. As a compound which has a some carboxyl group, and / or its anhydride, the thing similar to what was described by the polyester (meth) acrylate of the said polyfunctional (meth) acrylate compound can be illustrated. Moreover, as a polyhydric alcohol which has at least 1 (meth) acryloyloxy group, the thing similar to what was described by the said urethane (meth) acrylate oligomer can be illustrated.

In addition to the polymerizable oligomers described above, examples of the urethane (meth) acrylate oligomers include compounds obtained by reacting isocyanates with hydroxyl groups of hydroxyl group-containing polyesters, hydroxyl group-containing polyethers or hydroxyl group-containing (meth) acrylic acid esters. Can be. The hydroxyl group containing polyester used preferably is the hydroxyl group containing polyester obtained by esterification of the compound which has a polyhydric alcohol, carboxylic acid, and some carboxyl group, and / or its anhydride. As a polyhydric alcohol, the compound which has a some carboxyl group, and / or its anhydride, the thing similar to what was described by the polyester (meth) acrylate compound of a polyfunctional (meth) acrylate compound, respectively can be illustrated. The hydroxyl group containing polyether used preferably is a hydroxyl group containing polyether obtained by adding 1 type, or 2 or more types of alkylene oxide and / or (epsilon) -caprolactone to a polyhydric alcohol. The polyhydric alcohol may be the same as that which can be used for the hydroxyl group-containing polyester. As hydroxyl-containing (meth) acrylic acid ester used preferably, the thing similar to what was described by the urethane (meth) acrylate oligomer of a polymeric oligomer can be illustrated. As the isocyanates, compounds having one or more isocyanate groups are preferable in the molecule, and divalent isocyanate compounds such as tolylene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate are particularly preferable.

Said polymeric oligomer compound can be used individually or in combination of 2 or more types, respectively.

As a thermosetting resin, in addition to the thermosetting urethane resin containing an acryl polyol and an isocyanate prepolymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin are mentioned.

As the metal alkoxide, a silicon oxide matrix based on a silicon alkoxide-based material can be used. Specifically, it is tetramethoxysilane, tetraethoxysilane, etc., and it can be set as an inorganic type or organic-inorganic composite matrix (translucent resin) by hydrolysis or dehydration condensation.

(2) Photopolymerization Initiator

When using ultraviolet curable resin as a resin component which forms a translucent resin, it is preferable that a resin composition contains a photoinitiator (radical polymerization initiator).

As a photoinitiator, an acetophenone type photoinitiator, a benzoin type photoinitiator, a benzophenone type photoinitiator, a thioxanthone type photoinitiator, a triazine type photoinitiator, an oxadiazole type photoinitiator, etc. are used, for example. Moreover, as a photoinitiator, For example, 2,4,6-trimethylbenzoyl diphenyl phosphine oxide, 2,2'-bis (o-chlorophenyl) -4,4 ', 5,5'- tetraphenyl- 1, 2'-biimidazole, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, benzyl, 9,10-phenanthrenequinone, camphorquinone, methyl phenylglyoxylate, titanocene compound and the like can also be used. . The usage-amount of a photoinitiator is 0.5-20 weight part with respect to 100 weight part of resin components normally contained in a resin composition, Preferably it is 1-5 weight part.

(3) solvent

It is preferable that the solvent contained in a resin composition is an organic solvent. As an organic solvent, Aliphatic hydrocarbons, such as hexane, cyclohexane, an octane; Aromatic hydrocarbons such as toluene and xylene; Alcohols such as ethanol, 1-propanol, isopropanol, 1-butanol and cyclohexanol; Ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; Esters such as ethyl acetate, butyl acetate and isobutyl acetate; Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; Esterified glycol ethers such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; Cellulsolves such as 2-methoxyethanol, 2-ethoxyethanol and 2-butoxyethanol; Carbitols such as 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol and the like can be used.

Solvent may be used individually by 1 type, and may mix and use multiple types as needed. After coating of the resin composition, it is necessary to evaporate the organic solvent. Therefore, it is preferable that the boiling point of a solvent is the range of 60 degreeC-160 degreeC. Moreover, it is preferable that the saturated vapor pressure in 20 degreeC is 0.1 kPa-20 kPa.

Here, a composition having the same composition as the resin composition except that the above-mentioned mixture containing the translucent resin constituting the resin composition or the resin component and the solvent forming the resin composition, ie, the transparent microparticles (the resin composition is a photopolymerization initiator and a leveling agent). , In the case of containing other components such as a dispersant, an antistatic agent, and an antifouling agent, the surface tension at 25 ° C. of the above-mentioned mixture also includes the other components) is 18 mN / m or more and 35 mN / m or less. . If surface tension is less than 18 mN / m, the wettability of the resin composition with respect to a base film will become high too much, the smoothness of the surface of a coating layer will rise excessively, and the antifouling function generally given to a resin layer will fall. On the other hand, when surface tension exceeds 35 mN / m, the wettability of the resin composition with respect to a base film will become low too much, and the smoothness of the surface of a coating layer will deteriorate. The surface tension of the mixture is preferably 20 mN / m or more and 30 mN / m or less.

The surface tension of the said mixture can be adjusted with the kind of translucent resin or the resin component which forms this, the kind of solvent, or these mixing ratios. Surface tension can also be adjusted by adding additives, such as a leveling agent. For example, as the translucent resin or the resin component forming the same, a surface tension of about 25 to 45 mN / m is selected from the above, and as a solvent, a surface tension of about 20 to 40 mN / m among the above is selected. By selecting and adjusting these ratios, a mixture having a desired surface tension can be obtained.

The numerical value of the surface tension of the said mixture is a numerical value measured by the pendant-drop method (prevention method).

(4) light-transmitting fine particles

As for the translucent microparticles | fine-particles contained in a resin composition, the lower limit (henceforth a suspension methanol concentration lower limit) of the methanol solution of the methanol solution which can be suspended (dispersed) is 1.0 weight% or more and less than 15.0 weight%, Preferably it is 3.0 in 25 degreeC. It is in the range of 1 weight% or more and 13.0 weight% or less. Takei et al., Coating Engineering, Vol. 32, no. As described in 6, 1997, 218-223, the surface tension of the methanol solution at the lower limit of the suspended methanol concentration (the methanol concentration at which suspending of the translucent microparticles begins) is approximately equal to the surface tension of the translucent microparticles. When the methanol concentration lower limit is less than 1.0 wt% (that is, the light transmitting fine particles are suspended even in an aqueous methanol solution having a methanol concentration of less than 1.0 wt%), the difference between the surface tension of the light transmitting fine particles and the surface tension of the mixture increases. The dispersibility of the translucent microparticles | fine-particles to a mixture will become inferior, haze nonuniformity arises in the optical film obtained, or a bubble will generate | occur | produce in a resin layer, and an appearance quality will be impaired.

On the other hand, in the case where the lower limit of the suspended methanol concentration is 15.0 wt% or more (that is, when the translucent microparticles are suspended in an aqueous methanol solution only when the methanol concentration is 15.0 wt% or more), the surface tension of the translucent microparticles is too low. The dispersibility of the translucent microparticles | fine-particles of this becomes poor, a haze nonuniformity arises in an optical film obtained, or a bubble arises in a resin layer, and damages external appearance quality.

Since the difference between the surface tension of the translucent microparticles and the surface tension of the mixture is sufficiently small by using the transparent methanol having a lower limit of suspended methanol concentration of 1.0 wt% or more and less than 15.0 wt% at 25 ° C, the translucent microparticles are good for the mixture. It can disperse | distribute easily, and the optical film which was excellent in the homogeneity of haze and the generation | occurrence | production of the bubble in a resin layer was suppressed effectively by this can be obtained.

The lower limit of the suspended methanol concentration (the methanol concentration at which suspension of the translucent fine particles starts) is measured using an apparatus system such as that shown in FIG. 1. The apparatus system shown in FIG. 1 includes a container 10 for receiving pure water 80 (eg, a 100 mL beaker with a body outer diameter of 55 mm and a height of 73 mm); A stirrer 50 received in the vessel 10; A stirrer (magnetic stirrer) 40 for rotating the stirrer 50; A light source 20 for irradiating He-Ne laser light from the side surface of the container 10; A detector 30 that is in the form of an extension line of the laser light to be irradiated and is disposed on a side surface opposite to the side surface of the container 10 to which the laser light is irradiated; And a pump 60 for dropping methanol 90 into the vessel 10.

The lower limit of the suspended methanol concentration is measured as follows using the apparatus system shown in FIG. 1. First, 100 mL of pure water 80 (25 ° C.) is added to the container 10. Subsequently, 100 mg of the light-transmitting fine particles 70 are floated on the pure water surface, and the pure water 80 is stirred using the stirrer 40 and the stirrer 50 (rotational speed of the stirrer 50 at 200 rpm). Thereafter, this stirring is continued. Subsequently, methanol 90 (25 ° C.) is added dropwise to the pure water 80 under stirring using a pump 60 at a rate of 3 mL / min. Simultaneously with or before the dropping of methanol 90, the He-Ne laser light irradiation is started from the side of the container 10 using the light source 20, while facing the light source 20 through the container 10. The light intensity of the laser beam transmitted by the detector 30 at the position to be detected is detected, and the transmittance of the laser beam is monitored.

As the dropping of the above methanol proceeds, as shown in FIG. 2, when the methanol concentration of the aqueous methanol solution in the container 10 reaches a certain value, the suspension of the light-transmitting fine particles 70 starts, resulting in a laser beam. A sharp decrease in transmittance is observed. The lower limit of the suspended methanol concentration in the present invention is the methanol concentration at which the transmittance of the laser light begins to decrease sharply, and more specifically, referring to FIG. 2, the methanol concentration and the laser light obtained by using the apparatus system shown in FIG. 1. Methanol concentration A in the intersection of the tangent of the curve part before a sudden decrease of a transmittance, and the tangent of the curved part in which the transmittance is decreasing rapidly in the graph curve which shows the relationship with a transmittance | permeability.

Although commercially available products can also be used as the translucent microparticles | fine-particles which have the said predetermined suspended methanol concentration lower limit, when using a commercially available product which does not have a predetermined suspended methanol concentration lower limit, it is possible to adjust a suspended methanol concentration lower limit by washing with pure water. Do. Generally, the light-transmitting fine particles (light-transmitting fine particles containing a polymer) are produced by emulsion polymerization or suspension polymerization, and a surfactant including an emulsifier remains on the surface. The lower limit of the suspended methanol concentration can be increased by washing the light transmitting fine particles with pure water or the like and reducing the residual amount of the surfactant. In this case, the lower limit of the suspended methanol concentration can be adjusted by adjusting the washing conditions. In contrast, the lower limit of the suspended methanol concentration can be lowered by including the surfactant in the light transmitting fine particles. In this case, the lower limit of suspension methanol concentration can be adjusted by adjusting the amount of the surfactant to be contained.

The light transmitting fine particles may be organic fine particles or inorganic fine particles having light transmitting properties. For example, polystyrene, poly (meth) acrylate [including copolymers of polymethacrylate, polyacrylate and methacrylate monomers and acrylate monomers], polystyrene-poly (meth) acrylate copolymers, Organic fine particles which consist of a melamine resin, polyethylene, an organic silicone resin, etc., inorganic fine particles which consist of calcium carbonate, silica, aluminum oxide, barium carbonate, barium sulfate, titanium oxide, glass, etc. are mentioned. Moreover, the balloon of an organic polymer, and glass hollow beads can also be used. Especially, since the microparticles | fine-particles which show predetermined suspension methanol concentration lower limit are easy to be obtained, it is preferable that it is comprised from any polymer of a polystyrene, a poly (meth) acrylate, or a polystyrene- poly (meth) acrylate copolymer.

As the light transmitting fine particles, only one type of fine particles may be used, or two or more types of fine particles may be used. The shape of the light-transmitting fine particles may be any of spherical, flat, plate, needle, and indefinite shapes, but a spherical or substantially spherical shape is preferable.

The weight average particle diameter of the light-transmitting fine particles is preferably 5 μm or more and 10 μm or less, and the content of the light-transmitting fine particles in the resin composition is 25 parts by weight or more and 50 weight parts based on 100 parts by weight of the light-transmissive resin or the resin component forming the same. It is preferable that it is less than a part. By carrying out the weight average particle diameter and content of a translucent microparticle in the said range, when coating a resin composition on a base film and forming an anti-glare layer, the fall of display quality, such as scintillation, can be suppressed at a wide viewing angle, and high Front contrast and transmission image clarity can be obtained. The weight average particle diameter of the light-transmitting fine particles is more preferably 6 µm or more and 9 µm or less, and the content of the light-transmitting fine particles is more preferably 25 parts by weight or more based on 100 parts by weight of the light-transmissive resin or the resin component forming the same. It is below a weight part.

In addition, the weight average particle diameter of a translucent microparticle is measured using the Coulter multisizer (made by Beckman Coulter) based on the Coulter principle (pore electrical resistance method). When using 2 or more types of translucent microparticles from which a weight average particle diameter differs as a translucent microparticle, the said weight average particle diameter is the weight average particle diameter of the translucent microparticle which has the largest weight average particle diameter among the translucent microparticles | fine-particles.

It is preferable to make refractive index of translucent microparticles | fine-particles larger than the refractive index of translucent resin which comprises a resin layer, and it is preferable that the difference is the range of 0.04-0.1. By setting the difference in refractive index between the light-transmitting fine particles and the light-transmissive resin within the above range, when the resin layer is an anti-glare layer, not only the surface scattering due to irregularities on the surface of the anti-glare layer, Appropriate internal scattering can be expressed, and the occurrence of scintillation can be suppressed. Moreover, since it exists in the tendency to suppress whitening of an optical film, when said refractive index difference is 0.1 or less, it is preferable.

<Optical film>

The optical film of this invention is laminated | stacked on a base film and a base film, and is provided with the resin layer (typically an anti-glare layer, but may be a layer which has an optical function other than this) formed from the resin composition mentioned above. . It is a schematic sectional drawing which shows a preferable example of the optical film of this invention. The optical film 100 shown in FIG. 3 includes a base film 101 and an antiglare layer 102 laminated on the base film 101. The antiglare layer 102 is a layer based on the light transmissive resin 103, and the light transmissive fine particles 104 are dispersed in the light transmissive resin 103. The anti-glare layer 102 is formed by coating and drying the resin composition mentioned above on the base film 101, and hardening as needed. In the optical film 100 of FIG. 3, fine irregularities are formed on the surface of the antiglare layer 102 by the light-transmitting fine particles 104 dispersed and mixed.

In the optical film of the present invention, since the resin layer (antiglare layer 102) is formed using a resin composition having excellent dispersibility of the light-transmitting fine particles, the homogeneity of the haze is excellent, and the generation of bubbles in the resin layer It is suppressed and is excellent in appearance quality.

In addition, the optical film of this invention may have another layer (including adhesive layer) between a base film and a resin layer (anti-glare layer 102).

(1) base film

The base film 101 contains a translucent material, and glass, a plastic material, etc. can be used as a translucent material, for example. As a plastic material, what has appropriate transparency and mechanical strength is used, For example, polyester resins, such as cellulose acetate-type resins, such as TAC (triacetylcellulose), (meth) acrylic-type resin, polycarbonate resin, and polyethylene terephthalate, polyethylene And polyolefin resins such as polypropylene. The thickness of the base film 101 is 10-500 micrometers, for example, Preferably it is 10-300 micrometers from a viewpoint of thinning of an optical film.

(2) antiglare layer

The antiglare layer 102 is a layer based on the light transmissive resin 103, and the light transmissive fine particles 104 are dispersed in the light transmissive resin 103. The translucent resin 103 is the translucent resin itself when the resin composition contains the translucent resin, and the resin composition contains resin components such as active energy ray curable resins, thermosetting resins, and metal alkoxides. If it is, these are hardened | cured materials. That is, when the resin composition contains an active energy ray-curable resin, a thermosetting resin or a metal alkoxide, the translucent resin 103 is formed by curing the resin by irradiation or heating of the active energy ray.

The layer thickness T of the antiglare layer 102 is preferably 10 µm or more and 20 µm or less, and more preferably 12 µm or more and 18 µm or less. Thereby, the fall of display quality, such as scintillation, can be suppressed in a wide viewing angle, and high front contrast and transparent image clarity can be obtained. In addition, the layer thickness T of the antiglare layer 102 means the maximum thickness from the surface on the opposite side to the substrate film 101 of the antiglare layer 102 (see FIG. 3).

(3) manufacturing method of optical film

The optical film 100 shown in FIG. 3 which concerns on this invention can be manufactured suitably by the method containing the following process.

(A) Process of coating the above-mentioned resin composition containing translucent microparticles | fine-particles 104 on the base film 101, and forming a coating layer, and

(B) Process of forming anti-glare layer 102 by fixing a coating layer on the base film 101.

Coating on the base film 101 of a resin composition can be performed by the gravure coat method, the microgravure coat method, the rod coat method, the knife coat method, the air knife coat method, the kiss coat method, the die coat method, etc., for example.

For the purpose of improving the coatability of the resin composition or improving the adhesion with the antiglare layer 102, the surface of the base film 101 (surface of the antiglare layer 102 side) may be subjected to various surface treatments. Examples of the surface treatment include corona discharge treatment, glow discharge treatment, acid surface treatment, alkali surface treatment, ultraviolet irradiation treatment, and the like. In addition, you may form another layer, such as a primer layer, on the base film 101, and to apply a resin composition on this other layer.

In addition, when using an optical film as a protective film of the polarizing film mentioned later, in order to improve the adhesiveness of the base film 101 and a polarizing film, the surface of the base film 101 (antiglare layer 102 and Is preferably hydrophilized by various surface treatments (acid treatment or alkali treatment).

Next, in the said process (B), a coating layer is fixed on the base film 101, the anti-glare layer 102 is formed, and an optical film is obtained. Specifically, when the resin composition contains an active energy ray-curable resin, a thermosetting resin, or a metal alkoxide, after performing drying (removal of a solvent), the active layer is irradiated to the coating layer (active energy ray By using curable resin) or by heating (using thermosetting resin or metal alkoxide), the coating layer is cured. As an active energy ray, although it can select suitably from ultraviolet-ray, an electron beam, near-ultraviolet, visible light, near-infrared, infrared rays, X-rays, etc. according to the kind of resin component contained in a resin composition, among these, an ultraviolet-ray and an electron beam are preferable, and handling is especially easy. Ultraviolet light is preferable because it is simple and high energy can be obtained.

As the ultraviolet light source, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Moreover, ArF excimer laser, KrF excimer laser, an excimer lamp, a synchrotron radiation, etc. can also be used. Among these, an ultra high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a xenon arc, and a metal halide lamp are used preferably.

The electron beam may be 50 to 1000 keV, preferably 100, emitted from various electron beam accelerators such as cockcroft-walton type, van degraf type, resonant transformer type, insulating core transformer type, linear type, dynamtron type, and high frequency type. Electron beams with an energy of? 300 keV.

On the other hand, when a resin composition contains translucent resins, such as a thermoplastic resin, after drying (removing a solvent) or drying, a coating layer is softened or melted, and after that an optical coating layer is cooled, A film can be produced.

For example, in the case of using an ultraviolet curable resin, for example, a step of continuously sending the base film 101 wound in a roll shape, a step of coating and drying a resin composition containing the light-transmitting fine particles 104 and the ultraviolet curable resin, and coating An optical film can be manufactured continuously by the method including the process of hardening a layer and forming the anti-glare layer 102, and the process of winding up the obtained optical film.

In the optical film of the present invention, the surface irregularities of the antiglare layer 102 may be formed by transferring the surface of a mold (for example, an emboss roll) or by sand blasting. The schematic sectional drawing of the optical film produced by this method is shown in FIG. For example, using an ultraviolet curable resin, for example, using a mold having a transfer structure having a desired uneven shape on the surface, the coating layer is pressed from the base film 101 side while the surface of the mold is pressed against the surface of the coating layer. By irradiating an ultraviolet-ray with respect to it, the optical film as shown in FIG. 4 can be produced.

(4) Other Embodiment of Optical Film

The optical film of this invention may have a translucent resin layer containing the translucent resin laminated | stacked on the glare-proof layer 102 (surface opposite to the base film 101). Like the translucent resin layer 105 shown in FIG. 5, this translucent resin layer may have surface irregularities formed by transferring the surface of a mold (for example, an emboss roll) or by sand blasting. In the optical film provided with such a transparent resin layer, the surface of the antiglare layer 102 may be a smooth surface. Such a smooth surface can be formed by the method of hardening a coating layer, for example, pressing the mirror surface of the mold which has a mirror surface tightly to the surface of a coating layer.

In addition, the optical film of this invention may further be provided with the anti-reflective layer laminated | stacked on the anti-glare layer 102 (the surface opposite to the base film 101). The antireflection layer may be directly formed on the antiglare layer 102, or an antireflection film having an antireflection layer formed on a transparent film may be separately prepared and laminated on the antiglare layer 102 using an adhesive or an adhesive. The antireflection layer is provided in order to lower the reflectance endlessly, and by forming the antireflection layer, it is possible to more effectively prevent the reflection on the display screen. Examples of the antireflection layer include a low refractive index layer made of a material lower than the refractive index of the antiglare layer 102; The laminated structure of the high refractive index layer which consists of a material higher than the refractive index of the anti-glare layer 102, and the low refractive index layer which consists of a material lower than the refractive index of this high refractive index layer is mentioned. When laminating the antireflection film on the antiglare layer 102 using an adhesive or an adhesive, a commercially available antireflection film can be used.

<Anti-glare Polarizing Plate>

The optical film of this invention mentioned above can be made into an anti-glare polarizing plate by combining with a polarizing plate. An anti-glare polarizing plate is a multifunctional film having a polarizing function and an anti-glare function. The anti-glare polarizing plate of this invention is equipped with the polarizing plate which has a polarizing film at least, and the optical film of this invention laminated | stacked through the adhesive layer or the adhesive bond layer on the said polarizing plate so that the base film side may face the said polarizing plate. The polarizing plate may have a conventionally known configuration, and for example, generally has a protective film on one side or both sides of the polarizing film. In addition, the polarizing plate may be a polarizing film itself.

It is a schematic sectional drawing which shows a preferable example of the anti-glare polarizing plate of this invention. The anti-glare polarizing plate 400 illustrated in FIG. 6 includes a polarizing film 401, a protective film 402 adhered to one surface of the polarizing film 401, and an optical film 100 adhered to the other surface. ). The optical film 100 is stuck so that the base film 101 side may face the polarizing film 401 of a polarizing plate. The optical film 100 and the protective film 402 are adhere | attached to the polarizing film 401 through the adhesive bond layer which is not shown in figure. Such a configuration in which the polarizing film and the optical film are adhered through the adhesive layer, that is, the configuration in which the optical film is used as a protective film of the polarizing film is advantageous for thinning of the anti-glare polarizing plate.

As the polarizing film 401, for example, a dichroic dye in a film containing polyvinyl alcohol-based resin, polyvinyl acetate-based resin, ethylene / vinyl acetate (EVA) -based resin, polyamide-based resin, polyester-based resin, or the like Or a polyvinyl alcohol / polyvinylene copolymer containing molecular chains in which the dichroic dehydration product (polyvinylene) of polyvinyl alcohol is oriented in adsorption-oriented or molecularly oriented polyvinyl alcohol of iodine. The film etc. which are mentioned are mentioned. In particular, what adsorbed and oriented a dichroic dye or iodine to a polyvinyl alcohol-based resin film is suitably used as the polarizing film 401. Although there is no limitation in particular in the thickness of the polarizing film 401, Generally, from a viewpoint of thickness reduction of a polarizing plate, etc., 100 micrometers or less are preferable, More preferably, it is the range of 10-50 micrometers, More preferably, it is 25-35 micrometers. Range.

The protective film 402 adhered to the polarizing film 401 is preferably a film containing a polymer having low birefringence and excellent in transparency, mechanical strength, thermal stability, moisture shielding, and the like. As such a film, For example, Cellulose acetate type resins, such as TAC (triacetyl cellulose); (Meth) acrylic resins; Fluorine resins such as tetrafluoroethylene / hexafluoropropylene copolymers; Polycarbonate resin; Polyester-based resins such as polyethylene terephthalate; Polyimide resin; Polysulfone resins; Polyether sulfone type resin; Polystyrene resin; Polyvinyl alcohol-based resins; Polyvinyl chloride resins; The thing which molded-processed resin, such as polyolefin resin or polyamide resin, into a film form is mentioned. Among them, a triacetyl cellulose film obtained by saponifying a surface with an alkali or the like or a norbornene-based thermoplastic resin film can be preferably used in terms of polarization characteristics and durability. Since norbornene-type thermoplastic resin films have high moisture and heat resistance, the durability of the polarizing plate can be greatly improved, and since the hygroscopicity is low, the dimensional stability is high and is particularly suitable.

The shaping | molding process to a film can use the conventionally well-known method of the casting method, the calendar method, and the extrusion method. Although the thickness of the protective film 402 is not limited, 500 micrometers or less are preferable from a viewpoint of thinning of a polarizing plate, etc., More preferably, it is the range of 5-300 micrometers, More preferably, it is the range of 5-150 micrometers.

The anti-glare polarizing plate having the above configuration is typically adhered to the glass substrate of the liquid crystal cell through the pressure-sensitive adhesive layer or the like so that the optical film 100 becomes the light exit side (viewing side) when applied to the liquid crystal display device. .

<Liquid Crystal Display Device>

Next, the liquid crystal display device which concerns on this invention is demonstrated. The liquid crystal display device of this invention is equipped with the optical film or anti-glare polarizing plate of the said this invention. In one preferred embodiment, the liquid crystal display device of the present invention includes a backlight device, a light deflection means, a first polarizing plate (backlit side polarizing plate), a liquid crystal cell, a second polarizing plate (viewing side polarizing plate), and the above pattern. The optical film of this invention is provided in this order. It is a schematic sectional drawing which shows a preferable example of the liquid crystal display device of this invention. The liquid crystal display device 500 shown in FIG. 7 is a TN type liquid crystal display device in a normal white mode, and includes two prism films 504a and 504b as a backlight device 502, a light diffusion plate 503, and a light deflecting means. ), The first polarizing plate 505, the liquid crystal cell 501 and the second polarizing plate 506 in which the liquid crystal layer 512 is formed between the pair of transparent substrates 511a and 511b, and the optical film according to the present invention ( The anti-glare polarizing plate containing 507 is arrange | positioned in this order. The anti-glare polarizing plate is disposed such that the polarizing film side faces the liquid crystal cell 501.

The repair line of the light exit surface of the light diffusion plate 503 is substantially parallel to the Z axis shown in FIG. 7. On the other hand, when the light diffusion plate 503 is not provided, the repair line of the light exit surface (opening) of the backlight device 502 is substantially parallel to the Z axis. Moreover, the repair of the light incident surface of the prism films 504a and 504b is also substantially parallel to the Z axis.

As shown in FIG. 8, the 1st polarizing plate 505 and the 2nd polarizing plate 506 are arrange | positioned so that these transmission axes (Y direction, X direction, respectively) may become orthogonal Nicole relationship. In addition, each of the two prism films 504a and 504b has a light incidence surface side (backlight device 502) on a flat surface, and a linear prism on the light emission surface (surface facing the first polarizing plate 505) side. A plurality of 541a and 541b are formed in parallel. And the prism film 504a is arrange | positioned so that the direction of the ridgeline 542a of the linear prism 541a may become substantially parallel to the transmission axis direction of the 1st polarizing plate 505, and the prism film 504b is the linear It is arrange | positioned so that the direction of the ridge line 542b of the prism 541b may be substantially parallel to the transmission axis direction of the 2nd polarizing plate 506 which comprises an anti-glare polarizing plate. However, the direction of the ridge line 542b of the linear prism 541b of the prism film 504b is disposed to be substantially parallel to the transmission axis direction of the first polarizing plate 505, and the linear prism 541a of the prism film 504a. It is also possible to arrange | position so that the direction of ridgeline 542a may become substantially parallel to the transmission axis direction of the 2nd polarizing plate 506 which comprises an anti-glare polarizing plate. On the other hand, when setting a liquid crystal display device to the normal black mode, what is necessary is just to provide so that the transmission axis direction of the 1st polarizing plate 505 and the transmission axis direction of the 2nd polarizing plate 506 may become parallel.

Referring to FIG. 7, in the liquid crystal display device 500 having such a configuration, light emitted from the backlight device 502 is diffused by the light diffusion plate 503 and then incident on the prism film 504a. In the vertical cross section (ZX plane) orthogonal to the transmission axis direction of the 1st polarizing plate 505, the light inclined obliquely with respect to the lower surface of the prism film 504a turns out to a front direction, and will be emitted. Subsequently, in the prism film 504b, in the vertical cross section (ZY plane) orthogonal to the transmission axis direction of the second polarizing plate 506, light incident obliquely to the lower surface of the prism film 504b is as described above. Similarly, the course changes in the front direction and exits. Therefore, the light which passed the two prism films 504a and 504b is condensed in the front direction (Z direction) also in any vertical cross section, and the brightness of a front direction improves.

And as shown to FIG. 10 (a) and FIG. 10 (b), about 45 degrees with respect to the transmission axis 5a of the 1st polarizing plate 505, and the transmission axis 6a of the 2nd polarizing plate 506. In the plane 4b parallel to the angle forming direction and parallel to the front direction (Z direction), the angle (β) with the direction which is greatly inclined with respect to the front direction (Z direction), for example, the front direction (Z direction) ) Is reduced in the direction of the range of +35? + 60 ° and -35? -60 °. Thereby, in the liquid crystal display device 500 obtained, "black floating" in the approximately 45 degree direction is reduced from the transmission axis of a polarizing plate. The term "black floating" refers to a phenomenon in which a white color appears when black display is performed.

Referring again to FIG. 7, the light imparted with directivity in the front direction is incident on the liquid crystal cell 501 by the first polarizing plate 505 from linearly polarized light to linearly polarized light. Light incident on the liquid crystal cell 501 is emitted from the liquid crystal cell 501 by controlling the polarization plane for each pixel by the orientation of the liquid crystal layer 512 controlled by the electric field. The light emitted from the liquid crystal cell 501 passes through the second polarizing plate 506 and the optical film 507 and is emitted to the display surface side.

As described above, in the liquid crystal display device 500, by providing two prism films 504a and 504b, directivity toward the front direction of light incident on the liquid crystal cell 501 is high. Thereby, the brightness of the front direction improves, and "black floating" in the 45 degree direction is reduced from the transmission axis of a polarizing plate. Moreover, since the optical film 507 which concerns on this invention is used, it becomes difficult to produce the problem of display quality, such as scintillation, in a wide viewing angle, without causing the fall of front contrast, and also high transmit image clarity. You can get it.

Hereinafter, the structural member which comprises the liquid crystal display device of this invention is demonstrated in detail.

[Liquid crystal cell]

The liquid crystal cell 501 encapsulates a liquid crystal between a pair of transparent substrates 511a and 511b which are arranged to face each other at a predetermined distance with a spacer (not shown), and the pair of transparent substrates 511a and 511b. A liquid crystal layer 512 is provided. A transparent electrode and an oriented film are laminated | stacked and formed in each pair of transparent substrate 511a, 511b, and a liquid crystal is orientated by applying the voltage based on display data between transparent electrodes. Although the display system of the liquid crystal cell 501 is a TN system in the above-mentioned example, display systems, such as an IPS system and a VA system, may be sufficient.

[Backlight device]

The backlight device 502 includes a rectangular parallelepiped case 521 having an upper surface opening, and a cold cathode tube 522 as a linear light source arranged in parallel in a plurality of lines in the case 521. The case 521 is formed of a resin material or a metal material, and from the viewpoint of reflecting light emitted from the cold cathode tube 522 from the case inner circumferential surface, the case inner circumferential surface is preferably white or silver. As a light source, LEDs of various shapes, such as linear shape, can be used besides a cold cathode tube. In the case of using a linear light source, the number of linear light sources to be disposed is not particularly limited, but from the viewpoint of suppressing luminance unevenness of the light emitting surface, the distance between the centers of adjacent linear light sources is preferably in the range of 15 mm to 150 mm. . In addition, the backlight device 502 is not limited to that of the direct type | mold type | mold shown in FIG. 7, It can use various things, such as a side light type or a planar light source type which arrange | positioned the linear light source or a point light source on the side of a light guide plate. have.

[Light diffusing means]

The liquid crystal display device of the present invention can include a light diffusion plate 503 as light diffusing means disposed between the backlight device 502 and the light deflecting means. The light diffusion plate 503 is a film or sheet obtained by dispersing and dispersing a diffusion agent in a substrate. Examples of the substrate include poly (meth) acrylates such as polycarbonate resins and methacryl resins, copolymers of methyl methacrylate and styrene, copolymers of acrylonitrile and styrene, copolymers of methacrylic acid and styrene, and polystyrene systems Resins, polyvinyl chloride resins, polyolefin resins such as polypropylene and polymethylpentene, cyclic polyolefin resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins, polyarylate resins, and poly Mid type resin etc. can be used. The light diffusing means may be a combination of a light diffusing plate and a light diffusing film.

As the diffusing agent to be mixed and dispersed in the substrate, particles made of a material different from the material of the substrate are used. Examples of the diffusing agent include organic fine particles made of polystyrene, poly (meth) acrylate, polystyrene-poly (meth) acrylate copolymer, melamine resin, polyethylene, organic silicone resin, and the like, and calcium carbonate, silica, aluminum oxide, carbonate Inorganic fine particles made of barium, barium sulfate, titanium oxide, glass, or the like. The kind of diffusing agent to be used may be one type or two or more types. In addition, a balloon or an organic hollow bead of an organic polymer can also be used as the diffusing agent. The weight average particle diameter of the diffusing agent is preferably in the range of 0.5 to 30 µm. The shape of the diffusing agent may be spherical, flat, plate, needle, or the like, but is preferably spherical or substantially spherical.

[Prism film (light deflection means)]

As for the prism films 504a and 504b, a light incidence surface side (backlight device 502 side) is a flat surface, and an end surface is thin on the surface on the light emission side (surface opposite to the first polarizing plate 505). A plurality of polygonal, preferably triangular linear prisms 541a and 541b are formed in parallel. Examples of the material of the prism films 504a and 504b include poly (meth) acrylates such as polycarbonate resins, ABS resins, and methacrylate resins, methyl methacrylate-styrene copolymers, polystyrene resins, and acrylonitrile. Polyolefin resins, such as a styrene copolymer, polyethylene, and a polypropylene, or active energy-ray-curable resins, such as an ultraviolet curable resin and an electron beam curable resin, etc. are mentioned. A prism film can be manufactured by well-known methods, such as a release extrusion method, the press molding method, the injection molding method, the roll transfer method, the laser ablation method, the mechanical cutting method, the mechanical grinding method, and the photopolymer process method. These methods may be used independently, respectively, or may combine 2 or more types of methods. The thickness of the prism films 504a and 504b is 0.1-15 mm normally, Preferably it is 0.5-10 mm.

The cross-sectional shape in the vertical cross section orthogonal to the ridge lines 542a and 542b of the linear prisms 541a and 541b is, for example, a triangle. In this case, it is preferable that the vertex angle (theta) (refer FIG. 8) of the vertex which forms a ridgeline among the vertices of the said triangle is 90-110 degrees. In addition, although each side may be an equilateral side or an equilateral side, this triangle is preferably an isosceles triangle with two sides on the light exit side condensing in the front direction (normal direction of the display surface of the liquid crystal display device). . The cross-sectional shapes of the linear prisms 541a and 541b may be set in accordance with the characteristics of the light emitted from the surface light source, or may be shaped other than a triangle, such as giving a curve.

In the prism films 504a and 504b, a plurality of linear prisms 541a and 541b having, for example, a triangular cross section are sequentially arranged such that the bases facing the vertex angle of the triangle are adjacent to each other, and the plurality of linear prisms ( It is preferable to have a structure arranged so that the ridge lines 542a and 542b of 541a and 541b are substantially parallel to each other. In this case, as long as the condensing ability is not significantly reduced, the cross-sectional triangles of the linear prisms 541a and 541b may be curved at their vertices. The distance between each ridgeline is usually in the range of 10 to 500 µm, and preferably in the range of 30 to 200 µm. As viewed from the light exit surface side, the ridge lines 542a and 542b of the linear prism may be straight or curved. As viewed from the light exit surface side, the direction of the ridge line when the ridge line is a curved line means the direction of the regression line obtained by the least square method.

On the other hand, the light diffusing plate 503 and the prism films 504a and 504b may be integrally formed, or may be fabricated separately and then bonded together, and the light diffusing plate 503 and the prism films 504a and 504b. An air layer may be provided in between.

[Polarizing plate]

The above-mentioned thing can be used for the 2nd polarizing plate 506 which comprises an anti-glare polarizing plate. In addition, as a 1st polarizing plate 505, a conventionally well-known thing can be used.

[Retardation film]

As shown in FIG. 9, the liquid crystal display of the present invention may include a phase difference plate 508. In FIG. 9, the retardation plate 508 is disposed between the first polarizing plate 505 and the liquid crystal cell 501. The phase difference plate 508 has a phase difference of almost zero in a direction perpendicular to the surface of the liquid crystal cell 501. The phase difference plate 508 does not have any optical effect on the front side and exhibits a phase difference when viewed obliquely, so that the liquid crystal cell 501 To compensate for the phase difference caused by As a result, a wider viewing angle can be obtained, and superior display quality and color reproducibility can be obtained. The retardation plate 508 can be disposed between one or both of the first polarizing plate 505 and the liquid crystal cell 501 and between the second polarizing plate 506 and the liquid crystal cell 501.

As the retardation plate 508, for example, a polycarbonate resin or a cyclic olefin resin is molded into a film, and the film is further biaxially stretched, or a liquid crystalline monomer is applied to the film, and the molecular arrangement is changed by a photopolymerization reaction. And immobilized. Since the retardation plate 508 optically compensates for the arrangement of the liquid crystal, the retardation plate 508 uses a refractive index characteristic opposite to that of the liquid crystal arrangement. Specifically, in the liquid crystal cell of the TN mode, for example, "WV film" (manufactured by FUJIFILM Corporation) and the liquid crystal display cell of the STN mode are, for example, "LC film" (manufactured by Shin-Nihon Seki Co., Ltd.) and liquid crystal display of IPS mode. In the cell, for example, a biaxial retardation film and a liquid crystal display cell in VA mode include, for example, a retardation plate, a biaxial retardation film in which an A plate and a C plate are combined, and a liquid crystal display cell in a π cell mode. (Fuji Film Co., Ltd.) etc. can be used suitably.

Yes

Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples. The measuring method of various physical properties is as follows.

(a) Surface tension in 25 degreeC of the ultraviolet curable resin composition which does not contain translucent microparticles | fine-particles

It measured by the pendant-drop method (modern method) using "Contact Angle System OCA30L" by Eiko Seiki Corporation.

(b) Lower limit of suspended methanol concentration at 25 ° C. of light-transmitting fine particles

The lower limit of suspension methanol concentration was calculated | required according to the above-mentioned procedure using the powder wettability tester "WET-101P" by Lesca Corporation which has the apparatus structure shown in FIG.

(c) weight average particle diameter, standard deviation of particle size distribution, and coefficient of variation of light-transmitting fine particles

It measured using the Coulter multisizer (manufactured by Beckman Coulter) based on the Coulter principle (pore electrical resistance method).

(d) layer thickness of antiglare layer

About the obtained optical film, the maximum layer thickness was measured using a contact type film thickness meter ("DIGIMICRO MH-15" (the body) and "ZC-101" (counter) by a Nikon company), and the thickness of a base film is this value. The thickness of the antiglare layer was determined by subtracting 80 µm.

(e) Haze of optical film

In accordance with JIS K 7105, the haze in any 5 points | pieces of an optical film was measured using the haze computer ("HGM-2DP" by the Sugashi Kenki company), and the average value was made into the haze of an optical film. On the other hand, in order to prevent curvature of the film at the time of a measurement, and to improve measurement reproducibility, what bonded the base film side of the optical film to the glass substrate using the optically transparent adhesive as a sample for a measurement.

&Lt; Example 1 >

(1) Preparation of resin composition for antiglare layer formation

60 parts by weight of pentaerythritol triacrylate and 40 parts by weight of a polyfunctional urethane acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) are mixed with propylene glycol monomethyl ether to form an ultraviolet curing type having a solid content of 60% by weight. The resin composition was obtained. On the other hand, the refractive index of the hardened | cured material after removing propylene glycol monomethyl ether from this composition and UV-curing was 1.53.

Subsequently, with respect to 100 weight part of solid content of the said ultraviolet curable resin composition, crosslinked polystyrene-type particle | grains "XX367K" (made by Sekisuka Seihing Kogyo Co., Ltd. make, weight average particle diameter: 7.0 micrometers, standard deviation of a particle size distribution: 0.55 micrometer) 25 parts by weight of the coefficient of variation: 7.9%, the refractive index: 1.59), and 5 parts by weight of `` Lucirine TPO '' (BASF Co., Ltd., chemical name: 2,4,6-trimethylbenzoyldiphenylphosphine oxide) as a photopolymerization initiator. It diluted with propylene glycol monomethyl ether so that solid content might be 60 weight%, and prepared the resin composition for anti-glare layer formation.

The lower limit of the suspended methanol concentration at 25 ° C. of the crosslinked polystyrene particles “XX367K” was 12.3 wt%. In addition, the surface tension at 25 degrees C of the composition which is the same composition as the said resin composition except for not containing translucent microparticles | fine-particles was 28.2 mN / m.

(2) Production of embossing mold

The thing which copper ballad plating was given to the surface of the iron roll (STKM13A by JIS) of diameter 200mm was prepared. Copper ballad plating included a copper plating layer / thin silver plating layer / surface copper plating layer, and the thickness of the whole plating layer was about 200 micrometers. The copper-plated surface was mirror-polished, and on the polished surface, zirconia bead TZ-B125 (manufactured by Tosoh Corporation, average particle diameter) was used as the first fine particles using a blasting device (manufactured by Fuji Seisakusho Co., Ltd.): 125 µm) was blasted at a blast pressure of 0.05 MPa (gauge pressure, the same below) and the amount of fine particles used 16 g / cm 2 (the amount used per 1 cm 2 of the roll surface, the same below), thereby forming irregularities on the surface. On the uneven surface, zirconia bead TZ-SX-17 (manufactured by Tosoh Corporation, average particle diameter: 20 µm) was used as a second fine particle using a blasting device (manufactured by Fuji Seisakusho Co., Ltd.), and the blast pressure was 0.1. It blasted at 4 g / cm <2> of MPa and the usage-amount of microparticles | fine-particles, and fine-tunes the surface asperity. About the obtained copper plating iron roll with an unevenness | corrugation, the etching process was performed using the cupric chloride liquid (etching amount: 3 micrometers). Then, the chrome plating process was performed (chrome plating thickness: 4 micrometers), and the metal mold | die was produced. The Vickers hardness of the chrome plating surface of the obtained metal mold | die was 1000. Vickers hardness was measured in accordance with JIS Z 2244 using an ultrasonic hardness tester "MIC10" (manufactured by Krautkramer).

(3) production of optical film

The resin composition for antiglare layer formation was coated on a triacetyl cellulose (TAC) film (base film) having a thickness of 80 μm, and dried in a drier set at 80 ° C. for 1 minute. The base film after drying was pressed against the uneven surface of the metal mold | die produced by said (2) with the rubber roll so that a resin composition layer might become a metal mold | die side, and it adhered closely. In this state, the light from a high-pressure mercury lamp having a strength of 20 mW / cm 2 is irradiated so as to be 300 mJ / cm 2 in the amount of h-line converted light, the resin composition layer is cured, and the antiglare layer and the substrate having irregularities on the surface are exposed. The optical film of the structure shown in FIG. 4 containing a film was obtained. The layer thickness of the antiglare layer was 14.0 µm.

<Examples 2 to 3, Comparative Examples 1 to 2>

Except having changed the kind and / or addition amount of translucent microparticles | fine-particles as Table 1, the resin composition for anti-glare layer formation was prepared like Example 1, and the optical film was produced by the same method as Example 1. The detail of the used translucent microparticles | fine-particles is as follows.

(1) SX713L-2: Crosslinked polystyrene-based particle "SX713L-2" (made by Soken Kagaku Co., Ltd., weight average particle diameter: 7.0 micrometers, standard deviation of particle size distribution: 1.50 micrometers, coefficient of variation: 21.4%, refractive index: 1.59). The "SX713L" mentioned later was wash | cleaned with pure water, and the lower limit of suspension methanol concentration in 25 degreeC was 8.5 weight%.

(2) XX366K: Crosslinked polystyrene-based particle "XX366K" (made by Sekisuka Seihing Co., Ltd., weight average particle diameter: 8.1 micrometers, standard deviation of particle size distribution: 0.56 micrometer, coefficient of variation: 6.9%, refractive index: 1.59). The lower limit of suspension methanol concentration at 25 ° C. was 11.7 wt%.

(3) SX713L: Crosslinked polystyrene-based particle "SX713L" (manufactured by Soken Kagaku Co., Ltd., weight average particle size: 7.0 µm, standard deviation of particle size distribution: 1.50 µm, coefficient of variation: 21.4%, refractive index: 1.59). The lower limit of suspended methanol concentration at 25 ° C. was 0 wt% (ie dispersed with respect to pure water).

(4) SX713L-3: Crosslinked polystyrene-based particle "SX713L-3" (manufactured by Soken Kagaku Co., Ltd., weight average particle size: 7.0 µm, standard deviation of particle size distribution: 1.50 µm, coefficient of variation: 21.4%, refractive index: 1.59). The said "SX713L" was wash | cleaned with acetone, The lower limit of suspension methanol concentration in 25 degreeC was 23.6 weight%.

In Table 1, the addition amount of light transmitting microparticles | fine-particles is a weight part with respect to 100 weight part of solid content of an ultraviolet curable resin composition.

(Evaluation of nonuniformity of haze and bubble mixture)

About the arbitrary 1 m <2> range in the obtained optical film, it evaluated by visually confirming the nonuniformity of the haze (nonuniformity of the turbidity degree of a film), and the presence or absence of bubble mixing in an anti-glare layer. (Circle) and the case where either a nonuniformity of a haze or bubble mixing were confirmed were made into the case where the nonuniformity of a haze and bubble mixing were not confirmed. In addition, the haze value by the said measuring method of an optical film is combined with Table 1, and is shown.

As shown in Table 1, according to the resin composition in which the translucent fine particle-free resin composition has a surface tension within a predetermined range, and the lower limit of the suspended methanol concentration of the translucent fine particles is within a predetermined range, haze unevenness and bubble mixing of the optical film are included. It can be seen that it can effectively prevent the. On the other hand, the haze nonuniformity generate | occur | produced in the comparative examples 1 and 2 using the resin composition in which the lower limit of the suspended methanol concentration of translucent microparticles | fine-particles is not in a predetermined range.

Claims (8)

As a resin composition which consists of a translucent resin or the mixture containing the resin component and solvent which form this, and translucent microparticles | fine-particles,
The surface tension at 25 degrees C of the said mixture is 18 mN / m or more and 35 mN / m or less,
The said light-transmitting microparticles | fine-particles have a lower limit of the methanol concentration of the methanol solution which can be suspended, and this lower limit is 1.0 weight% or more and less than 15.0 weight% in 25 degreeC. The resin composition according to claim 1, wherein the light transmitting fine particles are composed of any polymer selected from the group consisting of polystyrene, poly (meth) acrylate, and polystyrene-poly (meth) acrylate copolymer. The resin composition of Claim 1 whose content of the said translucent microparticles | fine-particles is 25 weight part or more and less than 50 weight part with respect to 100 weight part of the said translucent resin or the resin component which forms this. The resin composition of Claim 1 whose weight average particle diameters of the said translucent microparticles | fine-particles are 5 micrometers or more and 10 micrometers or less. The optical film which has a base film and an anti-glare layer laminated | stacked on the said base film, and formed from the resin composition of Claim 1. A liquid crystal display device comprising a backlight device, light deflection means, a first polarizing plate, a liquid crystal cell, a second polarizing plate, and the optical film according to claim 5 in this order. The said optical deflecting means has two prism films which have a plurality of linear prisms on the surface opposing the said 1st polarizing plate,
One prism film is arrange | positioned so that the ridge direction of the linear prism may become substantially parallel to the transmission axis of the said 1st polarizing plate, and the other prism film has the ridge direction of the linear prism at the transmission axis of a said 2nd polarizing plate A liquid crystal display device arranged to be approximately parallel. The liquid crystal display device according to claim 6, further comprising a light diffusing means between the backlight device and the light deflecting means.

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