KR20060125266A - Coating composition for ultraviolet-curable film type and film prepared from it - Google Patents

Abstract

Provided are a coating composition for forming a radiation curing film which is remarkably low in refractive index even at a low temperature of 120 deg.C or less, a radiation curing film prepared by using the composition, and its preparation method. The coating composition comprises 60 wt% or more of a porous organic/inorganic hybrid nanoparticle; a radiation curing compound having an unsaturated functional group; a photoinitiator or a sensitizer; and a solvent. Preferably the porous organic/inorganic hybrid nanoparticle has an average diameter of 5-30 nm and a C/Si maximum ratio of 0.65, and is prepared by reacting a silane compound, a structure control agent, water rand a solvent by hydrolysis and condensation to prepare a porous nanoparticle having an average diameter of 5-30 nm; and removing the structure control agent from the nanoparticle.

Description

Coating composition for photocurable film formation and film prepared therefrom {COATING COMPOSITION FOR ULTRAVIOLET-CURABLE FILM TYPE AND FILM PREPARED FROM IT}

1 is a graph showing the change in refractive index according to the nanoparticle content.

The present invention relates to a coating composition for forming a photocurable film and a film prepared therefrom, and more particularly, to a porous silane compound having a particle size of a specific size for application to a low refractive film by using a structural control agent. After the formation, the structure control agent used for forming the pore was removed by a simple method prior to film formation, thereby making it possible to manufacture an ultra low refractive index film having a significantly low refractive index at a temperature lower than 120 ° C. A coating composition for forming a photocurable film suitable for use as a low refractive film or a low reflection film for use, and a film prepared therefrom.

Generally, when observing visual information such as an object or a character through a transparent substrate or observing an image from a reflective layer through a transparent substrate of a mirror, the transparent substrate is reflected by an external appearance, making it difficult to see visual information inside. there was.

In particular, with the development of display technology in recent years, the interest in the anti-reflection function is increasing as the screen size is increased and the screen is required to be clearer. When the anti-reflection function is applied to the transparent substrate, the glare caused by external light is prevented. As a result, a clearer image can be obtained.

Conventional techniques for preventing reflection of the surface of a transparent substrate include a method of forming a transparent metal oxide layer on a transparent substrate by chemical or physical vapor deposition. The method is excellent in antireflection effect by reducing the reflection of light in a large area, but the deposition process shows insufficient productivity for mass production, and its use is gradually decreasing recently.

In addition, a method for producing an antireflection film using a coating liquid containing silica and inorganic fine particles or a composition containing a fluorine-based low refractive organic substance, a fluorine-based organic substance-containing copolymer, a fluorine-based silane compound, or the like has been proposed.

However, the above-mentioned conventional techniques using the coating liquid containing the inorganic fine particles, the fluorine-based resin, and the like do not suggest a method for forming an ultra low refractive film having a refractive index of 1.4 or more and 1.36 or less. In particular, in the case of fluorine-based resins, there is an advantage that the refractive index may be lowered as the fluorine content is increased. There is a limit to lowering.

On the other hand, as a method of forming a low refractive or low reflection film, there are a method for producing a film using a siloxane-based curable resin and a method for producing a film using a photocurable resin such as an acrylic resin. In the case of silicone-based thermosetting resins, there is an advantage of low refractive index, but there is a problem that high temperature curing is required for the manufacture of the film and the curing time is long. On the other hand, acrylic photocurable resins can be cured in a short time by UV irradiation, which can shorten the curing time and form a film by low temperature process. Difficult to use as a membrane.

Recently, according to the needs of low dielectric materials in the semiconductor field, there are various methods of preparing an insulating film by introducing organic porogen or using a sol-gel process without using porogen. In order to improve dielectric properties, there is a problem in that a high temperature manufacturing process is used, and most compositions are not suitable for use in low refractive and anti-reflection films for displays.

Meanwhile, a porous particle was prepared by hydrolyzing and condensing silica using a structure controlling agent as a conventional method for preparing porous particles, and then treating the same at a high temperature of 400 to 500 ° C. or higher to remove the structure controlling agent. However, the prior art as described above had to be treated at a high temperature of 400 to 500 ° C. or higher, and the particles prepared after the heat treatment are also difficult to redistribute for producing the low refractive coating layer and have a large particle size, thereby preventing the obtaining of a transparent low refractive film. In addition, when the treatment is not performed at a high temperature of 400 to 500 ° C. or higher, there is a problem in that the refractive index is high when applied to a low refractive film which must be manufactured by a low temperature process such as a plastic substrate because the structural control agent is contained in the inorganic fine particles.

Therefore, it is possible to manufacture a low-refractive film that can be manufactured by a low temperature process by applying to a low refractive film, a curing time is short, and has a low reflection characteristic and excellent properties of various photocurable low reflection films. to be.

In order to solve the problems of the prior art as described above, the present invention is to form a porous (porous) using a structural control agent in the silane compound having a particle size of a specific size in order to apply to the low refractive film, By removing the used structural control agent in a simple manner before film formation, it is possible to manufacture a very low refractive index film with a very low refractive index at a temperature lower than 120 ° C., as well as a low refractive film or a low reflection film for various uses including a display. It is an object to provide the following suitable photocurable film-forming coating compositions and films prepared therefrom.

It is another object of the present invention to provide a photocurable coating composition for forming a photocurable film and a film prepared therefrom having a very simple photocuring process, excellent transparency and excellent basic properties to a low refractive film.

In order to achieve the above object, the present invention is a coating composition for forming a photocurable film,

a) porous organic / inorganic hybrid nanoparticles;

b) photocurable compounds having unsaturated functional groups;

c) photoinitiators or photosensitisers; And

d) solvent

It provides a coating composition for forming a photocurable film comprising a.

In another aspect, the present invention provides a method for producing a photocurable film, characterized in that the coating composition for forming a photocurable film is applied to a substrate and then cured.

The present invention also provides a photocurable film prepared by the above method.

Hereinafter, the present invention will be described in detail.

The present inventors formed a porous layer of a silane compound having a particle size of a specific size for application to a low refractive film by using a structural control agent, and then a simple method before forming the film using the structural control agent used for forming the pore. As a result of applying the porous organic / inorganic hybrid nanoparticles prepared by removing the photocurable coating composition to a photocurable film-forming film, it is possible not only to manufacture a very low refractive index film with a very low refractive index at a temperature lower than 120 ° C. It was confirmed that the film is suitable for use as a low refractive film or a low reflection film for use, and thus, the present invention has been completed.

The coating composition for forming a photocurable film of the present invention is characterized by comprising porous organic / inorganic hybrid nanoparticles, a photocurable compound having an unsaturated functional group, a photoinitiator or a photosensitizer, and a solvent.

The porous organic / inorganic hybrid nanoparticles of a) used in the present invention preferably have a size of 5 to 30 nm, more preferably 5 to 20 nm. When the size of the nanoparticles is less than 5 nm, there is a problem that it is not effective to lower the refractive index by using the final porous organic / inorganic hybrid nanoparticles, if the nanoparticles exceed 30 nm stability of the final porous organic / inorganic hybrid nanoparticles There is a problem that this is lowered, agglomeration is likely to occur, the opacity of the particles are lowered, and the gel can be easily generated during particle production.

Preferably, the porous organic / inorganic hybrid nanoparticles have a refractive index of 1.40, and more preferably, a maximum of 1.35, when preparing a membrane after low temperature drying. When the refractive index is greater than 1.40, there is a problem in that the refractive index is limited even if it includes a large amount of porous particles in the membrane composition.

In addition, it is preferable that the porous organic / inorganic hybrid nanoparticles have a specific composition, and in particular, the porous organic / inorganic hybrid nanoparticles have a C / Si of up to 0.65 in terms of production of porous nanoparticles, stability of particles, and membrane strength. desirable. When the C / Si of the porous organic / inorganic hybrid nanoparticles is low, the dielectric constant rapidly increases due to the increase of the unreacted groups in the particles, and thus is not suitable as a low dielectric material. It is preferable that C / Si has a value below a certain value because it does not increase significantly and increases the strength of the particles.

The porous organic / inorganic hybrid nanoparticles of a) are hydrolyzed and condensed with (i) a silane compound, ii) a structural control agent, iii) water, and iii) a solvent, and have a pore having an average particle diameter of 5 to 30 nm. After forming into nanoparticles, the average particle diameter is prepared by removing the structural control agent from the porous nanoparticles having a diameter of 5 to 30 nm.

The silane compound of i) used for the production of the nanoparticles may be any silane compound composed of silicon, oxygen, carbon, and hydrogen, and in particular, a silane compound represented by the following Chemical Formula 1 or Chemical Formula 2 is preferably used. Do.

[Formula 1]

[Formula 2]

In Formula 1 or Formula 2,

R ¹ is a non-hydrolyzable functional group which is hydrogen, fluorine, aryl, vinyl, allyl, or unsubstituted or substituted fluorine, straight or branched alkyl having 1 to 4 carbon atoms, preferably unsubstituted or substituted with fluorine. Linear or branched alkyl of 1 to 4 carbon atoms,

R ² and R ³ are each independently acetoxy, hydroxy, or straight or branched alkoxy having 1 to 4 carbon atoms.

The silane compound may be used alone or in a mixture of two components. It is preferable that the C / Si of the silane compound represented by the formula (2) is at most 0.65, more preferably 1 mole of the silane compound represented by the formula (1). It is preferable that C / Si is 0.5 or less. When the C / Si exceeds 0.65, there is a problem that it is difficult to manufacture stable particles of the final nanoparticles and the mechanical properties may be degraded.

As a structural control agent of ii) used in the preparation of the nanoparticles, it is possible to use a conventional structural control agent for controlling particle growth, and specifically, it is preferable to use a quaternary ammonium salt, more preferably Alkyl ammonium hydroxides, such as tetra methyl ammonium hydroxide, tetra ethyl ammonium hydroxide, tetra propyl alkyl ammonium hydroxide, or tetra butyl ammonium hydroxide, are used.

The alkyl ammonium hydroxide is a structural control agent and at the same time, it is not necessary to add a separate base catalyst in the preparation of the porous organic / inorganic hybrid nanoparticles of the present invention as a base catalyst, but if necessary to adjust the pH by adding a base catalyst By doing so, hydrolysis and condensation reactions can be carried out. At this time, usable base catalysts include ammonia water, organic amines and the like.

The structural control agent may be used by adjusting the amount of the structural control agent according to the type, reaction conditions, etc. of the structural control agent, in particular, it is preferably used in 0.05 to 0.25 moles, more preferably 0.06 to 0.15 moles per 1 mole of the silane compound. Will be. If the amount is less than 0.05, there is a problem that the gel may occur, if the amount exceeds 0.25 mole there is a problem that it is difficult to form a low refractive index film of less than 1.40 by using the particles growth is suppressed.

I) water used in the preparation of the nanoparticles is used for hydrolysis of the silane compound.

The water is preferably used in 0.5 to 10 moles, more preferably 1 to 5 moles per 1 mole of the hydrolyzable functional group of the silane compound. If the amount is less than 0.5 moles, sufficient hydrolysis and condensation reactions do not occur, and there is a problem that the low refractive properties and mechanical properties of the membrane may be lowered. If the amount exceeds 10 moles, gelation may occur during the hydrolysis and condensation reactions. It may occur, the uniformity of the components in the reaction solution is lowered, there is a problem that is not preferable in terms of mass production.

The solvent of i) used in the preparation of the nanoparticles is not particularly limited as long as it does not interfere with the hydrolysis and condensation reactions. Specifically, an aliphatic hydrocarbon solvent, alcohol solvent, ether solvent, ester solvent , Or an amide solvent or the like can be used, and it is particularly preferable to use an alcohol solvent.

The solvent is preferably used in an amount of 0.5 to 20 moles with respect to 1 mole of the hydrolyzable functional group of the silane compound. When the amount is less than 0.5 moles, the reaction rate may increase and there is a risk of gelation. There is a problem that the rate is reduced, the particles may not have sufficient porosity after the reaction.

As described above, the silane compound and the structural control agent are hydrolyzed and condensed under water and a solvent to form porous organic / inorganic hybrid nanoparticles.

Although the reaction conditions of the hydrolysis and condensation reaction is not particularly limited, it is particularly preferable to react for 1 to 40 hours with stirring at a temperature of 30 to 100 ℃. The reaction temperature may be maintained at a constant temperature during the reaction, or may be reacted while controlling the temperature intermittently or continuously.

As described above, the hydrolysis and condensation reaction may be carried out at normal pressure, and more preferably, when the reaction is carried out by pressing at a predetermined pressure or more, it is possible to produce porous particles having a lower refractive index. In general, it is preferable to seal and react the reactor at 5 to 70 ° C. or more above the boiling point of the reaction organic solvent. When the reaction temperature is less than 5 ℃ there is a problem that the pressure is not sufficiently applied, when the reaction at 70 ℃ or more has a problem that the reaction pressure is high and can not stably grow the particles.

When the porous organic / inorganic hybrid nanoparticles are manufactured to a certain size by the hydrolysis and condensation reaction as described above, and then the porous organic / inorganic hybrid nanoparticles are dried at low temperature to remove water and solvents and to produce a membrane by only the particles themselves The particles are grown so that the refractive index is at most 1.40, preferably at most 1.35. After growing the porous organic / inorganic hybrid nanoparticles, the structural control agent used for growing the porous particles is removed to prepare a final porous organic / inorganic hybrid nanoparticle.

As the method for removing the structural control agent, it can be removed using a conventional method such as an ion exchange resin method, an ultrafiltration method, or washing with water.

In order to effectively lower the refractive index by using the porous nanoparticles of a) can be prepared as described above it is preferable to use a specific content or more. For example, the porous hybrid nanoparticles do not decrease linearly with the content in the film-forming composition, and the refractive index rapidly decreases above a certain amount.

In addition, the porous organic / inorganic hybrid nanoparticles may be replaced with a secondary solvent after removing specific solvents, water, and alcohols, or after solvent replacement, or by-products, if necessary, to replace the final porous organic / inorganic hybrid nanoparticles. It can be manufactured.

The porous organic / inorganic hybrid nanoparticles prepared as described above are used in the coating composition without containing a structural control agent, wherein the porous organic / inorganic hybrid nanoparticles may be contained in the coating composition in the form of particles. It may also be contained in a colloidal state dispersed in a solvent. When such a coating composition is applied to a low refractive film, it is possible to apply to an ultra low refractive film manufactured at a low temperature of 120 ° C. or less.

In addition, the porous organic / inorganic hybrid nanoparticles do not decrease linearly according to the content in the film-forming composition, and since the refractive index drops sharply above a certain amount, it is preferable to use a specific amount with respect to the solid content of the coating composition.

Specifically, the content of the porous nanoparticles is preferably 60% by weight or more based on the solid content of the film-forming composition, more preferably 70% by weight or more, in which case the refractive index is sharply lowered to 1.40 or less More preferably, the ultra-low refractive photocurable film of 1.35 or less can also be manufactured.

As the photocurable compound having the unsaturated functional group of b) used in the present invention, it is preferable to use a photocurable compound having an ethylenically unsaturated bond capable of photopolymerization, which is usually used for hard coating. Specifically, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate having a number of ethylene groups of 2 to 14, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol Polyhydric alcohols, such as a tetra (meth) acrylate, the propylene glycol di (meth) acrylate whose number of propylene groups are 2-14, dipentaerythritol penta (meth) acrylate, or dipentaerythritol hexa (meth) acrylate, compounds obtained by esterifying to α, β-unsaturated carboxylic acids; Compounds obtained by adding (meth) acrylic acid to a compound containing a glycidyl group such as trimethylolpropane triglycidyl ether acrylic acid adduct or bisphenol A diglycidyl ether acrylic acid adduct; Ester compounds of a compound having a hydroxyl group or ethylenically unsaturated bond, such as a phthalic acid ester of β-hydroxyethyl (meth) acrylate or an adduct of toluene diisocyanate of β-hydroxyethyl (meth) acrylate, and a polyhydric carboxylic acid Or adducts with polyisocyanates; Or (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

The photocurable compound having an unsaturated functional group as described above may be mixed with a monofunctional acrylate compound having an ethylenically unsaturated bond, styrene, vinyltoluene, or the like, if necessary, mixed with a predetermined amount.

The photoinitiator or photosensitizer of c) used in the present invention is used for photocuring. The photoinitiator may be used acetophenones, benzophenones, Michler benzoyl benzoate, α- amyl oxime ester, or thioxanthones, and the like as a photosensitizer, n-butylamine, triethylamine, or Tri-n-butyl hose pine etc. can be used.

The photoinitiator or photo-sensitizer may be used alone or in combination, respectively, it is better to exhibit excellent photocurability when used in combination.

The coating composition for forming a film of the present invention comprising the above components includes the solvent of d), and the solvent may uniformly disperse the porous organic / inorganic hybrid nanoparticles and may be specifically limited to a solvent having excellent coating properties. It doesn't work.

The solvent may be used by mixing two or more of the same solvents used in the preparation of the porous organic / inorganic hybrid nanoparticles of a), in particular aliphatic hydrocarbon solvents, alcohol solvents, ether solvents, ester solvents, or Amide solvents and the like can be used, it can be used alone or in combination of two or more.

Coating composition for film formation of the present invention containing the above components may further comprise an additive as necessary.

The type and amount of the additives are not particularly limited in a range that does not impair the film properties, specifically conductive inorganic particles, salts, conductive polymers for improving the antistatic properties; Florin-containing silane compounds for improving stain resistance, Florin-containing photopolymerizable compounds; Alternatively, a silane compound or silica particles may be used for improving the strength.

In another aspect, the present invention provides a method for preparing a photocurable film prepared by applying a coating composition for forming a photocurable film comprising the above components to a substrate and curing the same, and a photocurable film prepared therefrom. The photocurable film can be produced as a photocurable low refractive film or a photocurable low reflection film having a refractive index of 1.40 or less, preferably 1.35 or less, compared with a conventional photocurable film having a refractive index of 1.45 or more.

The substrate may be a conventional transparent substrate, and specifically, a plastic sheet such as glass, polycarbonate, acrylic resin, PET, or TAC, a plastic film, or a plastic lens ), Or a plastic panel can be used.

The method of applying the coating composition for forming a photocurable film of the present invention to the substrate as described above is not particularly limited, and may vary depending on the characteristics and the coating amount of the coating liquid. Examples thereof include roll coating, gravure coating, and dip. The coating, bar coating, spray coating, spin coating, or extrusion coating can be carried out by conventional methods.

The photocurable film of the present invention prepared as described above may be used by forming another film above and below the film in order to impart functionality, and examples thereof include: an adhesive layer for imparting adhesion; Primer layer; Or a layer for imparting antistatic, abrasion resistance, fouling resistance, and the like; And the like, and functional additives may be added as necessary to impart functionality.

The photocurable film of the present invention as described above can be used for various displays such as word processors, computers, televisions, or plasma display panels; A surface of the polarizing plate used in the liquid crystal display device; Optical lenses such as sunglasses lenses made of transparent plastics, eyeglass lenses with frequency, or finder lenses for cameras; A low reflection film on the surface of a cover of various instruments or a glass of an automobile or a train; Brightness enhancement film; Or an optical waveguide film.

The coating composition for forming a photocurable film of the present invention as described above has a very simple process of photocuring, has excellent transparency, and has a significantly lower refractive index than a general photocuring resin, such as a low refractive film and a low reflection film for various applications including a display. Can be used as

Hereinafter, preferred examples are provided to help understanding of the present invention, but the following examples are merely to illustrate the present invention, and the scope of the present invention is not limited to the following examples.

EXAMPLE

Example 1

34 g of methyltrimethoxysilane (MTMS), 52 g of tetraethoxysilane (TEOS), and 161 g of ethanol (EtOH) were mixed and stirred at room temperature. 102 g of 10 wt% aqueous tetrapropyl ammonium hydroxide (TPAOH) diluted with 66 g of distilled water was added to the mixed solution, and the mixture was sufficiently mixed. Then, the temperature was raised to 80 ° C., and the transparent silicate was reacted at this temperature for 20 hours. The solution was prepared. The silicate solution was cooled to room temperature, cooled to 0 ° C. in an ice-bath, and 6.4 g of 65% by weight aqueous nitric acid solution (HNO ₃ ) was added thereto, followed by stirring for 30 minutes. The resulting solution was diluted with an ether solvent.

The diluted solution was washed with distilled water to remove by-products, and solvent-substituted with propylene glycol methyl ether acetate (PGMEA) using a rotary evaporator to obtain 15% by weight of porous organic / inorganic hybrid nanoparticles. 212 g of dispersed colloid were prepared. In this case, the refractive index of the dried film using only the nanoparticles was 1.269.

4.7 g of the colloid dispersed 15 wt% of the porous organic / inorganic hybrid nanoparticles prepared above and 2.0 g of a pyreneglycol methyl ether acetate solution containing 15 wt% of pentaerythritoltetraacrylate (PETA) dissolved therein were mixed. Thereafter, 60 mg of 2,2-dimethoxy-2-phenyl-acetophenone was added to prepare a coating composition for forming a low refractive film.

Example 2

Except for using 81 g of 10 wt% tetrapropyl ammonium hydroxide aqueous solution diluted with 84 g of distilled water in Example 1, reacting at 70 ° C., and using 5.1 g of 65 wt% aqueous nitric acid solution. In the same manner as in Example 1, 212 g of a colloid in which porous organic / inorganic hybrid nanoparticles were dispersed was prepared. In this case, the refractive index of the film dried using only the nanoparticles was 1.263.

5.3 g of the colloid dispersed 15 wt% of the porous organic / inorganic hybrid nanoparticles prepared above, and 1.3 g of the propylene glycol methyl ether acetate solution containing 15 wt% of pentaerythritoltetraacrylate (PETA) dissolved therein were mixed. After that, 40 mg of 2,2-dimethoxy-2-phenyl-acetophenone was added to prepare a coating composition for forming a low refractive film.

Example 3

122 g of a 10 wt% tetrapropyl ammonium hydroxide aqueous solution diluted with 48 g of distilled water in Example 1 was subjected to hydrothermal reaction at 90 ° C. for 12 hours, and 7.6 g of 65 wt% aqueous nitric acid solution was used. Then, the same procedure as in Example 1 was carried out to prepare 212 g of a colloid in which porous organic / inorganic hybrid nanoparticles were dispersed. In this case, the refractive index of the film dried using only the nanoparticles was 1.234.

4.7 g of the colloid dispersed 15 wt% of the porous organic / inorganic hybrid nanoparticles prepared above, and 2.0 g of the pyreneglycol methyl ether acetate solution containing 15 wt% of dipentaerythritolhexaacrylate (DPHA) are mixed. After that, 60 mg of 2,2-dimethoxy-2-phenyl-acetophenone was added to prepare a coating composition for forming a low refractive film.

Example 4

In Example 1, using 45 g of methyltrimethoxysilane, 35 g of tetraethoxysilane, and 81 g of 10 wt% tetrapropyl ammonium hydroxide aqueous solution diluted with 77 g of distilled water, and reacted at 60 ° C, A colloidal 215 g of porous organic / inorganic hybrid nanoparticles was dispersed in the same manner as in Example 1, except that 3.6 g of 65 wt% aqueous nitric acid solution was used. In this case, the refractive index of the film dried using only the nanoparticles was 1.274.

4.7 g of the colloid in which the prepared 15 wt% porous organic / inorganic hybrid nanoparticles were dispersed, and 2.0 g of a propylene glycol methyl ether acetate solution containing 15 wt% of dipentaerythritolhexaacrylate (DPHA) was dissolved. After mixing, 60 mg of 2,2-dimethoxy-2-phenyl-acetophenone was added to prepare a coating composition for forming a low refractive film.

Example 5

Example 1, except that 102 g of 10% by weight aqueous tetrapropyl ammonium hydroxide diluted with 27 g of methyltrimethoxysilane, 63 g of tetraethoxysilane, and 70.5 g of distilled water was used in Example 1. 209 g of a colloid in which porous organic / inorganic hybrid nanoparticles were dispersed was prepared. In this case, the refractive index of the film dried using only the nanoparticles was 1.288.

5.0 g of the prepared 15% by weight porous organic / inorganic hybrid nanoparticles dispersed therein and 1.7 g of a propylene glycol methyl ether acetate solution in which 15% by weight of pentaerythritoltetraacrylate (PETA) is dissolved are mixed. Thereafter, 50 mg of 2,2-dimethoxy-2-phenyl-acetophenone was added to prepare a coating composition for forming a low refractive film.

Example 6

104 g of tetraethoxysilane (TEOS) and 184 g of ethanol (EtOH) were mixed and stirred at room temperature. 61 g of 25% by weight aqueous tetrapropyl ammonium hydroxide solution (TPAOH) diluted with 98 g of distilled water was added to the mixture, and the mixture was sufficiently mixed. Then, the temperature was raised to 80 ° C. and the reaction was carried out at this temperature for 30 hours. Was prepared. After the silicate solution was cooled to room temperature, the temperature was lowered by an ice bath at 0 ° C., and 9.5 g of 65% by weight aqueous nitric acid solution (HNO ₃ ) was added thereto, followed by stirring for 30 minutes, and the resulting solution was diluted with water and an ethanol solvent.

The diluted solution was removed using a ultrafiltration membrane and solvent-substituted with ethanol to prepare 200 g of a colloid in which 15 wt% of porous organic / inorganic hybrid nanoparticles were dispersed. In this case, the refractive index of the film dried using only the nanoparticles was 1.295.

5.3 g and 15 wt% of pentaerythritol tetraacrylate and perfluorohexanediol diacrylate (1H, 1H, 6H, 6H-perfluoro-) in which colloidal dispersion of the prepared 15 wt% porous organic / inorganic hybrid nanoparticles was dispersed. 1,6-hexanediol diacrylate) was mixed with 1.3 g of a mixture of propylene glycol methyl ether acetate dissolved in a weight ratio of 7: 3, and then 2,2-dimethoxy-2-phenyl-acetophenone (2, 2-dimethoxy-2-phenyl-acetophenone) 40 mg was added to prepare a coating composition for low refractive film formation.

Example 7

Pentaerythritol tetraacrylate (PET) and perfluorohexanediol diacrylate (1H, 1H, 6H, 6H-perfluoro-1,6 in place of 15% by weight of pentaerythritoltetraacrylate (PETA) in Example 2 -hexanediol diacrylate) was carried out in the same manner as in Example 2 except for using a mixture in a weight ratio of 7: 3 to prepare a coating composition for forming a low refractive index.

Comparative Example 1

The same procedure as in Example 1 was carried out except that 64 g of 10 wt% tetrapropyl ammonium hydroxide aqueous solution diluted with 119 g of distilled water was reacted at 60 ° C., and 15.9 g of 65 wt% aqueous solution of nitric acid was used. In the same manner as in Example 1, 2.0 g of a solution containing 15% by weight of the hybrid siloxane resin and 4.7 g of a propylene glycol methyl ether acetate solution containing 15% by weight of pentaerythritol tetraacrylate were mixed. A coating composition for forming a low refractive index film was prepared in the same manner as in Example 1 except that 140 mg of dimethoxy-2-phenyl-2-acetophenone was added.

Comparative Example 2

A coating composition for forming a low refractive index film was prepared in the same manner as in Example 7, except that 5.3 g of the solution in which the 15 wt% hybrid siloxane resin prepared in Comparative Example 1 was dispersed in Example 7 was used.

Comparative Example 3

A photocurable coating composition was prepared by adding 150 mg of 2,2-dimethoxy-2-phenyl-acetophenone to 5.0 g of propylene glycol methyl ether acetate solution containing 15% by weight of dipentaerythritol hexaacrylate.

Comparative Example 4

To 5.0 g of 15% by weight propylene glycol methyl ether acetate solution containing a mixture of pentaerythritol tetraacrylate and perfluorohexanediol diacrylate in a weight ratio of 7: 3, 2,2-dimethoxy-2-phenyl -150 mg of acetophenone was added to prepare a photocurable coating composition.

Using the coating compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 4 as described above, the refractive index, mechanical strength, and minimum reflectance were measured as follows, and the results are shown in Table 1 below.

A) Refractive index-After spin coating the coating composition prepared in Examples 1 to 7 and Comparative Examples 1 to 4 at 2,000 rpm on a silicon wafer (baking) at 80 ℃ for 90 seconds, the high pressure mercury The lamp was exposed to an energy of 200 mJ / cm 2 under a high-pressure mercury lamp. Then, after further baking for 30 minutes at 100 ° C., the refractive index of the film was measured using an ellipsometer.

B) Mechanical strength-The elastic modulus and strength of the film were measured using a nanoindenter using the coating compositions prepared in Examples 1 to 7 and Comparative Examples 1 to 4 above.

C) Lowest reflectivity (low reflection characteristics of the low refractive film)-Antireflection film after the coating composition prepared in Examples 1 to 7 and Comparative Examples 1 to 4 coated with a wire bar on the TAC film and then cured by the above method The lowest reflectance in visible light was measured by using a spectroscopic reflectance meter, and more than 2.5% was insufficient, 1.5-2.5% was excellent, and less than 1.5% was very good.

division Refractive index Modulus of elasticity (GPa) Strength (GPa) Reflectance Example 1 1.391 6.7 0.50 Great Example 2 1.341 5.1 0.43 Very good Example 3 1.385 6.5 0.49 Great Example 4 1.351 4.6 0.38 Very good Example 5 1.378 7.1 0.65 Great Example 6 1.349 9.2 0.82 Very good Example 7 1.317 4.7 0.41 Very good Comparative Example 1 1.480 7.7 0.43 Inadequate Comparative Example 2 1.475 9.5 1.10 Inadequate Comparative Example 3 1.528 7.6 0.40 Inadequate Comparative Example 4 1.531 8.0 0.40 Inadequate

Through the above Table 1, the refractive index of the photocurable resin film prepared using the film-forming coating composition of Examples 1 to 7 according to the present invention shows a significantly lower refractive index compared to Comparative Examples 1 to 4, low reflection The characteristics were also confirmed to be excellent.

In addition, the refractive index according to the nanoparticle content is measured and the results are shown in FIG. 1, and as shown in FIG. 1, more preferably, when the content of the nanoparticles is 60 wt% or more with respect to the total solid content of the coating composition for forming a film. In the case of 70% by weight or more, it was confirmed that the refractive index was significantly reduced. Therefore, it was found that the content of the nanoparticles contained in a specific amount or more is very preferable in terms of lowering the refractive index.

The coating composition for forming a photocurable low refractive film or a low reflection film according to the present invention may be formed by using a structural control agent on a silane compound having a particle size of a specific size in order to be applied to a low refractive film. The use of porous organic / inorganic hybrid nanoparticles with a simple method of removing the structural control agent used for the formation of the film enables the manufacture of ultra low refractive films with a significantly lower refractive index at temperatures below 120 ° C. There is an effect that can be used as a low refractive film or a low reflection film of various uses, including.

Although only described in detail with respect to the described embodiments of the present invention, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, it is natural that such variations and modifications belong to the appended claims. .

Claims (14)

In the coating composition for forming a photocurable film, a) porous organic / inorganic hybrid nanoparticles; b) photocurable compounds having unsaturated functional groups; c) photoinitiators or photosensitisers; And d) solvent Coating composition for forming a photocurable film comprising a. The method of claim 1, Coating composition for forming a photocurable film, characterized in that the average particle diameter of the porous organic / inorganic hybrid nanoparticles of a) is 5 to 30 nm, C / Si is up to 0.65. The method of claim 1, The coating composition of claim 1, wherein the porous organic / inorganic hybrid nanoparticles of a) are included in at least 60% by weight based on the total solids of the coating composition for forming a film. The method of claim 1, The porous organic / inorganic hybrid nanoparticles of a) are hydrolyzed and condensed with iii) a silane compound, ii) a structural control agent, iii) water, and iii) a solvent, and have a mean particle size of 5 to 30 nm. After the formation, the coating composition for forming a photocurable film, characterized in that prepared by removing the structural control agent from the porous nanoparticles having an average particle diameter of 5 to 30 nm. The method of claim 4, wherein A coating composition for forming a photocurable film, characterized in that the silane compound of (iii) is a silane compound represented by the following Chemical Formula 1 or Chemical Formula 2: [Formula 1]

[Formula 2]

In Formula 1 or Formula 2, R ¹ is a non-hydrolyzable functional group which is hydrogen, fluorine, aryl, vinyl, allyl, or unsubstituted or substituted fluorine, straight or branched alkyl having 1 to 4 carbon atoms, R ² and R ³ are each independently acetoxy, hydroxy, or straight or branched alkoxy having 1 to 4 carbon atoms. The method of claim 4, wherein The structural control agent is at least one selected from alkyl ammonium hydroxides consisting of tetra methyl ammonium hydroxide, tetra ethyl ammonium hydroxide, tetra propyl alkyl ammonium hydroxide, and tetra butyl ammonium hydroxide. Coating composition for photocurable film formation. The method of claim 4, wherein The coating composition for forming a photocurable film, characterized in that the structural control agent is used in an amount of 0.05 to 0.25 mol based on 1 mol of the silane compound. The method of claim 4, wherein The coating composition for forming a photocurable film, characterized in that the structural control agent is removed by ion exchange resin method, ultrafiltration, or washing with water. The method of claim 1, The photocurable compound which has the unsaturated functional group of said b) is ethylene glycol di (meth) acrylate, the polyethyleneglycol di (meth) acrylate whose number of ethylene groups is 2-14, trimethylol propane tri (meth) acrylate, penta Erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propylene glycol di (meth) acrylate having 2 to 14 propylene groups, dipentaerythritol penta (meth) acrylate, or dipentaerythritol hexa ( Compound obtained by esterifying the polyhydric alcohol of meth) acrylate to (alpha), (beta)-unsaturated carboxylic acid, the compound obtained by adding (meth) acrylic acid to the compound containing the glycidyl group of the trimethylolpropane triglycidyl ether acrylic acid addition product To a compound containing a glycidyl group of a bisphenol A diglycidyl ether acrylic acid addition product ( (A) an ester compound or polyisocyanate with a compound obtained by adding acrylic acid, a compound having a hydroxyl group or an ethylenically unsaturated bond of an adduct of toluene diisocyanate of phthalic acid ester of phthalic acid ester of β-hydroxyethyl (meth) acrylate, The adduct of the adduct of the addition product of the toluene diisocyanate of toluene diisocyanate of (beta) -hydroxyethyl (meth) acrylate, the compound which has a hydroxyl group, and ethylenically unsaturated bond, and polyhydric carboxylic acid, and the adduct of polyisocyanate, and methyl (meth Photocurable, characterized in that at least one selected from the group consisting of (meth) acrylic acid alkyl esters of acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate Coating composition for film formation. The method of claim 1, The photoinitiator of c) is acetophenones, benzophenones, Michler benzoylbenzoate, α-amyl oxime ester, or thioxanthones, and the photosensitizer is n-butylamine, triethylamine, or tri- It is n-butyl hose pine, The coating composition for photocurable film formation characterized by the above-mentioned. A method for producing a photocurable film, characterized in that the coating composition for forming a photocurable film of claim 1 is applied to a substrate and then cured. A film produced by the method of claim 11. The method of claim 12, And the film is a low refractive film or a low reflection film. The method of claim 12, The film is a surface of a polarizing plate used in a word processor, a computer, a television or a plasma display panel, a liquid crystal display device, a sunglasses lens, a spectacle lens with a camera, a finder lens for a camera, a cover of an instrument, a glass of a vehicle, a glass of a tank, A film characterized by being used as a brightness enhancement film or an optical waveguide film.

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