JP2009091448A - Resin composition for hard coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard coating agent which exhibits satisfactory hardness and is reduced in the contraction by curing, and also is excellent in adhesivity and is reduced in the irregularity of light interference. <P>SOLUTION: This resin composition for hard coating comprises (A) 20-35 pts.wt. of a specific acryloxy-functional silanol and/or its partial condensate, (B) 7-10 pts.wt. of colloidal silica, (C) 18-30 pts.wt. of pentaerythritol triacrylate, (D) 1-10 pts.wt. of a photopolymerization initiator and (E) 35-39 pts.wt. of an ester-based solvent. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a resin composition for hard coat used for surface protection of a cellulose ester optical film.

  Cellulose ester optical films such as triacetyl cellulose are generally used as protective films for polarizing plates, but to prevent the surface from being scratched by handling during production, and when used on the outermost surface. In order to prevent scratches due to user use, a hard coat layer is provided on one side or both sides.

Furthermore, the cellulose ester optical film is provided with an antistatic layer, an antireflection layer utilizing light interference, an electromagnetic wave shielding layer, an infrared ray absorbing layer, a water- and oil-repellent antifouling layer, a color tone adjusting layer, and the like on the surface. Are provided for specific purposes. In providing these various coating layers, the hard coat layer is a base layer provided as an essential component for increasing the film strength. As for this hard-coat layer, it is common that various active energy ray hardening resin and thermosetting resin are used in the range whose film thickness is 1-20 micrometers (patent documents 1-5). However, when the hard coat layer is provided, there are insufficient pencil hardness, uneven light interference, poor adhesion to the surface of the cellulose ester film, and the occurrence of film curling, and improvements have been desired.
Japanese Patent Laid-Open No. 10-95861 JP 2005-148110 A JP-A-57-13214 JP 2002-245672 A JP 2003-338089 A

  The present invention has been made in view of the above problems, and its object is to improve pencil hardness, light interference unevenness, adhesion, and film curling when a hard coat layer is formed on a cellulose ester optical film. The object is to provide a resin composition for coating.

  In the prior art, the surface hardness has been increased by using a large amount of polyfunctional acrylate monomers, and thus there have been many problems in curing shrinkage. In order to solve such a shrinkage problem, it may be possible to reduce the shrinkage by replacing the acrylic monomer resin skeleton itself with a soft component, but the hardness is extremely reduced and the light interference unevenness is reduced. There is a problem that it cannot be used as a hard coating agent for protecting the surface of optical plastic films.

  Therefore, it is basically difficult to reduce the curing shrinkage while maintaining the hardness, and there is a demand for a hard coating agent that achieves both hardness and low curing shrinkage and has excellent adhesiveness and less light interference unevenness. It was.

  The above object of the present invention is achieved by the following configurations.

That is, the present invention
(A) The following general formula

(In the formula, R ¹ is a monovalent hydrocarbon group, R ² is a divalent hydrocarbon group, R ³ is a hydrogen atom or a monovalent hydrocarbon group, and x is an integer of 1 to 4) An acryloxy-functional silanol and / or a partial condensate thereof;
(B) Colloidal silica; 7 to 10 parts by weight
(C) pentaerythritol triacrylate; 18-30 parts by weight
(D) Photopolymerization initiator; 1 to 10 parts by weight
(E) Ester solvent; hard coat resin composition containing 35 to 39 parts by weight, and hard coat layer having a thickness of 1 to 20 μm formed by applying light after coating the hard coat resin composition. It is a cellulose ester optical film.

  According to the present invention, when a hard coat layer is formed on a cellulose ester optical film, it is possible to provide a resin composition for hard coat in which pencil hardness, light interference unevenness, adhesion, and film curling are improved.

  Hereinafter, the present invention will be described in detail.

  The component (A) used in the present invention is an acryloxy functional silanol and / or a partial condensate thereof, which can be obtained by hydrolyzing an acryloxy functional silane represented by the following general formula.

(Wherein R ¹ , R ² , R ³ and x are the same as above)
Component (B) is colloidal silica which is one of the essential components of the present invention. Colloidal silica is a dispersion of submicron particle size silica (SiO ₂ ) in an aqueous medium or other solvent medium.

Colloidal silica is useful in constructing hard coating compositions. The reason is that silica (SiO ₂ ) reacts with various alkoxysilanes and hydrolysates or partial condensates thereof to form a polysiloxane skeleton for coating. That is, the formation of the polysiloxane skeleton is effective for imparting excellent scratch resistance and anti-curl property.

  Component (C) is pentaerythritol triacrylate, which is an essential component for developing curability and adhesion.

  As the photopolymerization initiator of the component (D), any known publicly available one can be used, but in order to ensure transparency particularly in the visible region, the maximum wavelength peak of UV absorption is 400 nm or less. Things are desirable. As such a polymerization initiator, acetophenone-based 1-hydroxy-cyclohexyl-phenyl ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-hydroxy-2-methyl-1-phenyl-propane -1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone -1-one, phosphine oxide-based 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, benzophenone and polymerization accelerators ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate Combinations such as these can also be used. These may be used singly or a plurality of them may be combined to optimize the curing conditions according to the light source during photocuring. In particular, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, which is liquid and easy to handle, is desirable because it is liquid and easy to handle, and is used by previously dissolving other polymerization initiators as listed above. You can also

  Component (E) is an ester solvent, and ethyl acetate or butyl acetate is preferably used.

  In this invention, the compounding quantity of (A), (B) and (C) component is (A) component; 20-35 weight part, (B) component; 7-10 weight part, (C) component; 18 to 30 parts by weight. When it is out of this range, for example, when the component (A) is small, the hard coat layer becomes brittle and cracks easily occur. As the number increases, the film curl increases. When the amount of the component (B) is small, the hardness of the cured film is lowered and the hard coat is not suitable. When the amount is large, the hard coat layer becomes brittle and cracks are likely to occur. When the amount of the component (C) is small, there is a problem that the adhesion of the cured film is reduced and the film is easily peeled off. On the other hand, when the amount is large, the hardness of the cured product is lowered and the hard coat is not suitable.

  The amount of the component (D) is an amount necessary for initiation of photopolymerization and is not particularly limited, but is generally 1 to the above components (A), (B) and (C). The amount is preferably 10 parts by weight, and more preferably 3 to 8 parts by weight in view of the curing speed and stability over time.

  The amount of the (E) ester solvent is 35 to 39 parts by weight.

  To produce the hard coat agent used in the present invention, aqueous colloidal silica (colloidal silica aqueous dispersion), silyl acrylate, trifunctional pentaerythritol triacrylate or a mixture thereof, a photoinitiator and, if desired, other above-mentioned Add any of the additives. Colloidal silica can be used in the same manner even if it is preliminarily dispersed in an alcohol solvent. Examples of the alcohol include methanol, ethanol, isopropyl alcohol, and 1-methoxy-2-propanol. The colloidal silica preferably has a primary particle size of 40 nm or less, particularly 25 nm or less in order to ensure film transparency.

  In the first step, the silane coupling agent having a reactive (meth) acrylate group is hydrolyzed in the reaction system by hydrolyzing the silyl acrylate in the presence of aqueous colloidal silica and a water-miscible alcohol. A mixture of the hydrolyzate and its partial condensate and colloidal silica is prepared.

  In this step, it is preferable that a radical polymerization inhibitor is allowed to coexist to suppress polymerization and from the viewpoint of yield.

The radical polymerization inhibitor is not particularly limited, and any radical polymerization inhibitor can be used as long as it is generally used as a radical polymerization inhibitor. Specifically, quinone polymerization inhibitors such as hydroquinone, methoxyhydroquinone, benzoquinone, p-tert-butylcatechol; 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2-tert- Alkylphenol polymerization inhibitors such as butyl-4,6-dimethylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol; alkylated diphenylamine, N, N '-Diphenyl-p-phenylenediamine, phenothiazine, 4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 1,4-dihydroxy- 2,2,6,6-tetramethylpiperidine, 1-hydroxy-4- Amine polymerization inhibitors such as benzoyloxy-2,2,6,6-tetramethylpiperidine; copper dithiocarbamate polymerization inhibitors such as copper dimethyldithiocarbamate, copper diethyldithiocarbamate, copper dibutyldithiocarbamate; 2,2, 6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1
1-oxyl-based polymerization inhibitors such as esters of -oxyl and 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl;

  Among these, preferable radical polymerization inhibitors include quinone polymerization inhibitors, amine polymerization inhibitors, copper dithiocarbamate polymerization inhibitors, and 1-oxyl polymerization inhibitors. Particularly preferred radical polymerization inhibitors include hydroquinone, methoxyhydroquinone, benzoquinone, p-tert-butylcatechol, phenothiazine, alkylated diphenylamine, copper dibutyldithiocarbamate, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4 Examples include -hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, esters of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and the like.

  Suitable alcohols include, for example, water miscible alcohols, specifically t-butanol, methanol, ethanol, propanol, butanol and the like, or ether alcohols such as ethoxyethanol, butoxyethanol, methoxypropanol and the like. The aqueous colloidal silica and silyl acrylate are heated and stirred until hydrolysis is completed. Hydrolysis of silyl acrylate can be carried out under atmospheric conditions or by heating and refluxing the hydrolysis mixture.

  In the second step, trifunctional pentaerythritol triacrylate is added to the above solution 1, and the water and solvent used in the reaction are distilled off.

  Further, in the third blending step, the desired light is applied to the acrylic resin in which the hydrolyzate of the silane coupling agent having a reactive (meth) acrylate group and the mixture of the partial condensate and colloidal silica are dispersed in the second step. Add initiator and ester solvent.

  The order of addition of the above-described components to the hard coat agent used in the present invention is not important, but it is preferable to add pentaerythritol triacrylate or a mixture thereof to the above-mentioned mixture of hydrolyzed silyl acrylate and colloidal silica.

  When producing the hard coat agent used in the present invention, an azeotropic mixture of water and alcohol is distilled off from the above blend. If sufficient alcohol is not used to distill off the water contained in the initial hydrolysis mixture as an azeotrope, add a sufficient amount of alcohol to facilitate removal of the water by distillation. Can do.

  Light that is commercially available by applying the hard coat solution described above to the surface of the polycarbonate substrate by roll, wire bar, doctor blade, flow, spray, brushing, etc., and selecting a photopolymerization initiator as appropriate. It can be cured with an irradiation device.

  In the present invention, the hard coat agent is formed with a thickness of 1 to 20 μm, preferably 5 to 15 μm. When the film thickness decreases, the influence of polymerization inhibition by oxygen during photocuring increases, and a curing system under an inert gas such as nitrogen is required. Further, when the film thickness becomes extremely large, there is a problem that the deformation of the base material during curing shrinkage becomes large.

  It has been found that when a hard coat layer is formed on a film, pencil hardness, light interference unevenness, adhesion, and film curling are improved.

  Conventionally, when a hard coat layer is provided on the surface of a cellulose ester film, the film surface is subjected to corona discharge treatment, plasma discharge treatment, alkali treatment, adhesion layer for the purpose of improving adhesion and suppressing film curling without causing light interference unevenness. The method of providing, or providing a curling adjustment layer in either of the front and back is taken. On the other hand, the present invention does not require these processing steps and adjustment layers, and thus contributes to improvement in productivity, cost reduction, and stability.

  These active energy ray-curable resin layers can be applied by a known method.

As a light source for forming a cured film layer of an ultraviolet curable resin by a photocuring reaction, any light source that generates ultraviolet rays can be used without any limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the amount of irradiation light is preferably about ²⁰ to 500 mJ / cm ² .

  The ultraviolet curable resin composition is preferably irradiated with ultraviolet rays during or after coating and drying, and the irradiation time is preferably 0.5 seconds to 5 minutes, and 3 seconds from the viewpoint of curing efficiency or work efficiency of the ultraviolet curable resin. More preferred is ~ 2 minutes.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. Moreover, a part shows a weight part in an Example.

The evaluation method is as follows.
(Adhesion)
A lattice-shaped crosscut was created on the surface of the film on which the cured film was formed in accordance with the test method of JIS K 5600-5-6, and a 25 mm wide cellophane tape peel test was performed. Evaluation was made as follows.
○: All cells remain Δ: 20 cells remain ×: Less than 20 cells remain (interference unevenness)
A black adhesive tape is bonded to the opposite surface of the sample where the hard coat layer is formed, and the angle illuminated from the hard coat layer forming side with a three-wavelength fluorescent lamp and an interference fringe inspection lamp (FNA-18 manufactured by Funatech Corporation) Interference unevenness was observed and evaluated by changing the viewing angle in various ways.
A: No interference fringes are observed in any of the interference fringe inspection lamp and the three-wavelength fluorescent lamp.
○: Slightly observed with interference fringe inspection lamp, but not observed with 3-wavelength fluorescent lamp.
Δ: Observed with an interference fringe inspection lamp, but only slightly observed with a three-wavelength fluorescent lamp.
X: Observed with an interference fringe inspection lamp, but also observed with a three-wavelength fluorescent lamp.
(curling)
A sample was cut out with a size of 100 mm × 20 mm square, and was conditioned for one day under the conditions of 23 ° C. and 55% RH, and then the curvature radius of the curl of the sample was measured in millimeters and evaluated.

Example 1
65.94 parts isopropyl alcohol, 205.67 parts Snowtex O-40 (40% colloidal silica aqueous dispersion) manufactured by Nissan Chemical Industries, Ltd. 35.10 parts γ-methacryloxypropyltrimethoxysilane, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 46.08 parts of pentaerythritol triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 337.57 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 102.42 parts of ethyl acetate was added and diluted. A photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one 7 was added to a mixed solution of the hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and pentaerythritol triacrylate. After adding 17 parts and adjusting to a solid content concentration of 60%, pressure filtration was performed to obtain a hard coat agent.

Using the hard coat agent thus obtained, a triacetyl cellulose film having a film thickness of 80 μm was coated with a Mayer bar so that the hard coat film thickness after curing was 10 μm, and oven-dried at 80 ° C. After drying the solvent for 3 minutes in the machine, hard coat by irradiating twice with UV irradiation conditions of 330 mW / cm ² , 350 mJ / cm ² and line speed of 4 m / min using F-450 and H valves manufactured by Fusion A film was formed.
The evaluation results are shown in Table 1.

Example 2
63.26 parts isopropyl alcohol, Snowtex O-40 (40% colloidal silica aqueous dispersion) manufactured by Nissan Chemical Industries, Ltd. 197.34 parts, 33.67 parts γ-methacryloxypropyltrimethoxysilane, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 68.53 parts of pentaerythritol triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 315.78 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 114.48 parts of ethyl acetate was added and diluted. A photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one 6 was added to a mixed solution of the hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and pentaerythritol triacrylate. .88 parts was added and the solid content concentration was adjusted to 60%, followed by pressure filtration to obtain a hard coat agent.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Example 3
59.81 parts of isopropyl alcohol, 186.56 parts of Snowtex O-40 (40% colloidal silica aqueous dispersion) manufactured by Nissan Chemical Industries, Ltd. 31.83 parts of γ-methacryloxypropyltrimethoxysilane, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 97.56 parts of pentaerythritol triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 287.60 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 130.08 parts of ethyl acetate was added and diluted. A photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one 6 was added to a mixed solution of the hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and pentaerythritol triacrylate. After adding 51 parts and adjusting to a solid content concentration of 60%, pressure filtration was performed to obtain a hard coat agent.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Example 4
65.94 parts isopropyl alcohol, 205.67 parts Snowtex O-40 (40% colloidal silica aqueous dispersion) manufactured by Nissan Chemical Industries, Ltd. 35.10 parts γ-methacryloxypropyltrimethoxysilane, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 46.08 parts of pentaerythritol triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 337.57 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 102.42 parts of isobutanol was added and dissolved by dilution. A photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one 7 was added to a mixed solution of the hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and pentaerythritol triacrylate. After adding 17 parts and adjusting to a solid content concentration of 60%, pressure filtration was performed to obtain a hard coat agent.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Comparative Example 1
Isopropyl alcohol 68.12 parts, Nissan Chemical Industries Snowtex O-40 (40% colloidal silica aqueous dispersion) 212.47 parts, γ-methacryloxypropyltrimethoxysilane 36.26 parts, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 27.77 parts of trimethylolpropane triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 355.34 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 92.59 parts of methyl ethyl ketoxime was added and diluted. To this mixed solution of hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and trimethylolpropane triacrylate, a photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one After adding 7.41 parts and adjusting to solid content concentration 60%, pressure filtration was performed and the hard-coat agent was obtained.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Comparative Example 2
Isopropyl alcohol 68.12 parts, Nissan Chemical Industries Snowtex O-40 (40% colloidal silica aqueous dispersion) 212.47 parts, γ-methacryloxypropyltrimethoxysilane 36.26 parts, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 27.77 parts of trimethylolpropane triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 355.34 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  To this liquid, 92.59 parts of isobutanol was added and diluted. To this mixed solution of hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and trimethylolpropane triacrylate, a photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one After adding 7.41 parts and adjusting to solid content concentration 60%, pressure filtration was performed and the hard-coat agent was obtained.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Comparative Example 3
Isopropyl alcohol 68.12 parts, Nissan Chemical Industries Snowtex O-40 (40% colloidal silica aqueous dispersion) 212.47 parts, γ-methacryloxypropyltrimethoxysilane 36.26 parts, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 27.77 parts of trimethylolpropane triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 355.34 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  The liquid was diluted and dissolved by adding 92.59 parts of methyl isobutyl ketone. To this mixed solution of hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and trimethylolpropane triacrylate, a photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one After adding 7.41 parts and adjusting to solid content concentration 60%, pressure filtration was performed and the hard-coat agent was obtained.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Comparative Example 4
Isopropyl alcohol 68.12 parts, Nissan Chemical Industries Snowtex O-40 (40% colloidal silica aqueous dispersion) 212.47 parts, γ-methacryloxypropyltrimethoxysilane 36.26 parts, 4-hydroxy- A mixture of 0.05 part of 2,2,6,6-tetramethylpiperidine-1-oxyl (radical polymerization inhibitor) was heated to reflux for 3 hours.

  After cooling, 200 parts of isobutanol and 27.77 parts of trimethylolpropane triacrylate were added, and the solvent was distilled off under reduced pressure. When about half of the solvent was distilled, 355.34 parts of isobutanol was added, the water contained in the colloidal silica aqueous dispersion was further distilled off azeotropically, and then all of the solvent was distilled off to give a viscous opaque liquid. Got.

  The liquid was diluted and dissolved by adding 92.59 parts of ethyl acetate. To this mixed solution of hydrolyzate and partial condensate of (meth) acrylate silane, colloidal silica and trimethylolpropane triacrylate, a photopolymerization initiator 2-hydroxy-2-methyl-1-phenyl-propan-1-one After adding 7.41 parts and adjusting to solid content concentration 60%, pressure filtration was performed and the hard-coat agent was obtained.

A hard coat film was formed in the same manner as in Example 1 using the hard coat agent thus obtained.
The evaluation results are shown in Table 1.

Claims (2)

(A) The following general formula

(In the formula, R ¹ is a monovalent hydrocarbon group, R ² is a divalent hydrocarbon group, R ³ is a hydrogen atom or a monovalent hydrocarbon group, and x is an integer of 1 to 4) An acryloxy-functional silanol and / or a partial condensate thereof;
(B) Colloidal silica; 7 to 10 parts by weight
(C) pentaerythritol triacrylate; 18-30 parts by weight
(D) Photopolymerization initiator; 1 to 10 parts by weight
(E) Ester solvent: Hard coat resin composition containing 35 to 39 parts by weight.   A cellulose ester optical film having a hard coat layer having a thickness of 1 to 20 µm formed by applying the resin composition for hard coat according to claim 1 and then curing with light.