JP2012173698A - Composition for anti-reflection coating, article using the same, and anti-reflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for anti-reflection coatings forming a low-refractive index layer on a high-refractive index layer simultaneously therewith by a single coating, drying and hardening process on a substrate, efficiently achieving the anti-reflection by controlling the coating thickness of the low-refractive index layer, and capable of forming the anti-reflection coating without depending on a coating device, to provide an article having an anti-reflection coating formed of the composition for the anti-reflection coatings, and to provide particularly an anti-reflection film.SOLUTION: The composition for anti-reflection coatings contains: porous silica particles (A) having a volume average diameter within a range of 80 to 150 nm and a variation coefficient within 0 to 40% and having pores on the surface; and a binder resin (B). The porous silica particles are surface-modified with silazane compound (C). The composition used for the anti-reflection coating is formed by modifying 100 pts.mass of the porous silica particles (A) with 0.3-60 pts.mass of the silazane compound (C).

Description

  The present invention relates to a composition for an antireflection film suitable for forming an antireflection film for preventing an image from being reflected on an article. The present invention also relates to an article having an antireflection film formed of the composition for antireflection film, particularly a liquid crystal display (LCD), an organic EL display (OELD), a plasma display (PDP), a surface electric field display (SED), a field emission. The present invention relates to an antireflection film for preventing a decrease in contrast and reflection of an image caused by reflection of external light on the surface of a display screen of an image display device such as a display (FED).

  Since the surface of the display screen of an image display device such as a liquid crystal display (LCD) is smooth, external light is likely to be reflected, and the reflection of the external light reduces the contrast of the display screen and causes an image to appear. The displayed content is difficult to see. In order to prevent reflection of this external light, an antireflection film designed to reduce the reflectance using the principle of optical interference is disposed on the outermost surface of the image display device.

  The antireflective film usually has a low refraction made of a material having a refractive index lower than the refractive index of a coating layer such as a hard coat layer or an antistatic layer provided on the substrate or the substrate surface so that optical interference occurs In general, a rate layer is provided on a substrate or a coating layer. Since the low refractive index layer can efficiently realize antireflection, it needs to have a film thickness of about 100 nm and precise film thickness control is required. Therefore, conventionally, a low refractive index layer has been formed by a vapor deposition method such as a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method in which film thickness control is relatively easy. However, when the low refractive index layer is formed by the vapor deposition method, the film formation is performed in a vacuum, so that there is a problem that the productivity is low and it is not suitable for mass production.

  On the other hand, as a method for forming a low refractive index layer, there is a method in which a coating material containing a low refractive index substance such as hollow silica particles is applied to a substrate. This method has the advantage of high productivity and is suitable for mass production, but has a problem that it is difficult to control the film thickness as compared with the vapor deposition method. Furthermore, when the high refractive index layer is provided under the low refractive index layer, two coating, drying, and curing steps are required, resulting in a problem that productivity is lowered.

  Therefore, it has been studied to simultaneously form a low refractive index layer on a high refractive index layer by a single coating, drying, and curing process. For example, low refractive index fine particles having a refractive index of 1.50 or less and An optical film in which a curable composition containing a binder resin is coated on a transparent plastic film substrate to form a cured layer having a dry thickness of 1.0 to 40 μm, and what is a cured layer substrate? An optical film in which low refractive index fine particles are unevenly distributed on the surface portion on the opposite side has been proposed (see, for example, Patent Document 1). In Examples of Patent Document 1, hollow silica particles having an average particle diameter of 40 nm are used as the low refractive index fine particles. However, the hollow silica particles having such an average particle diameter are likely to aggregate and contain the low refractive index fine particles. It has been difficult to precisely control the thickness of the low refractive index layer to a thickness of about 100 nm that can efficiently realize antireflection.

  Further, in order to eliminate aggregation of the hollow silica particles, an organic solvent and a surface modifier are added to the hollow silica particles and dispersed strongly by a wet jet mill, and the surface modifier is reacted and added to the surface of the hollow silica particles. Modified hollow silica particles have been proposed (see, for example, Patent Document 2). However, since the shell of the hollow silica particles is thin and does not have mechanical strength, if it is dispersed strongly using a wet jet mill or the like, the shell of the hollow silica particles breaks and the binder resin is placed inside the hollow silica particles. There was a problem of entering and no longer having a low refractive index. In addition, when a coating material containing hollow silica particles is applied, there is a problem that the shell of the hollow silica particles is broken even when a coating apparatus such as a gravure coater or a roll coater is used.

  Therefore, a low refractive index layer can be simultaneously formed on the high refractive index layer by a single coating, drying, and curing process on the substrate, and the low refractive index layer can effectively realize antireflection about 100 nm. Therefore, there is a demand for a material that does not break down the low-refractive-index substance even when using a coating apparatus that can control the film thickness so as to have a thickness of 5 mm.

JP 2007-86764 A JP 2009-107857 A

  The problem to be solved by the present invention is that a low refractive index layer can be simultaneously formed on a high refractive index layer by a single coating, drying and curing process on a substrate, and the film thickness of the low refractive index layer Is to provide a composition for an antireflection film that is controlled in film thickness so that antireflection can be efficiently realized, and can form an antireflection film without depending on a coating apparatus. Moreover, it is providing the articles | goods which have the anti-reflective film formed with this composition for anti-reflective films, especially an anti-reflective film.

  As a result of intensive studies, the inventors of the present invention have determined that low-refractive-index particles of porous silica particles having a volume average diameter and a coefficient of variation in a specific range, and surface-modified with a silazane compound in a specific range of modification amount. As a result, the inventors have found that a low refractive index layer can be simultaneously formed on a high refractive index layer by a single application, drying, and curing process on a substrate, and the present invention has been completed.

  That is, the present invention provides a porous silica particle (A) and a binder resin (B) having a volume average diameter of 80 to 150 nm, a coefficient of variation of 0 to 40%, and pores on the surface. A composition for an antireflective film, wherein the porous silica particles are surface-modified with a silazane compound (C), and the silazane compound (C) with respect to 100 parts by mass of the porous silica particles (A). It is related with the composition for anti-reflective films characterized by being modified by 0.3-60 mass parts. The present invention also relates to an article having an antireflection film formed from the composition for antireflection film, particularly to an antireflection film.

  The composition for an antireflection film of the present invention has high mechanical properties of porous silica particles, which are low-refractive-index substances, so that even during dispersion treatment, a high force is applied during preparation. Even when a coating apparatus in which pressure is applied to the coating material is used, the porous silica particles are not destroyed, so that there is an advantage that the antireflection property does not deteriorate during preparation and coating. Therefore, when the antireflection film is formed on the article surface, any coating method can be used, and a stable and excellent antireflection film can be formed on the article surface.

  In particular, the antireflective film in which the base material is a film and the antireflective film is formed with the composition for antireflective film of the present invention is a low refractive index whose thickness is controlled so that antireflection can be efficiently realized on the outermost surface Since the rate layer is formed, it has excellent antireflection properties. Therefore, external light is reflected on the surface of a display screen of an image display device such as a liquid crystal display (LCD), an organic EL display (OELD), a plasma display (PDP), a surface electric field display (SED), or a field emission display (FED). Therefore, it is possible to use an antireflection film that prevents a decrease in contrast and image reflection caused by the above.

1 is an observation photograph of a cross section of an antireflection film formed of the composition for antireflection film of Example 2 at a magnification of 50,000 with a field emission scanning electron microscope (FE-SEM). FIG. 2 is an observation photograph of the cross section of the antireflection film formed from the composition for antireflection film of Example 3 at a magnification of 50,000 with a field emission scanning electron microscope (FE-SEM). FIG. 3 is a photograph of an antireflection film formed from the composition for antireflection film of Example 4 observed at a magnification of 100,000 times by a field emission scanning electron microscope (FE-SEM). FIG. 4 is an observation photograph of the cross section of the antireflection film formed from the composition for antireflection film of Example 5 at a magnification of 50,000 with a field emission scanning electron microscope (FE-SEM). FIG. 5 is an observation photograph of the cross section of the antireflection film formed of the composition for antireflection film of Comparative Example 2 at a magnification of 50,000 with a field emission scanning electron microscope (FE-SEM).

  The composition for an antireflection film of the present invention has a volume average diameter in the range of 80 to 150 nm, a coefficient of variation in the range of 0 to 40%, and porous silica particles (A) having a pore on the surface and a binder A composition for an antireflection film containing a resin (B), wherein the porous silica particles are surface-modified with a silazane compound (C), and 100 parts by mass of the porous silica particles (A), The silazane compound (C) is modified with 0.3 to 60 parts by mass.

  The composition for an antireflection film of the present invention can be formed as an antireflection layer in which porous silica particles (A) are substantially arranged in a single layer on the surface of the coating film made of the binder resin (B). . In the present invention, a film including both the antireflection layer made of the porous silica particles (A) and the coating layer made of only the binder resin (B) is referred to as an antireflection film.

  In order to make the antireflection layer made of the porous silica particles (A) to have a film thickness capable of efficiently preventing reflection of about 100 nm, the volume average diameter of the porous silica particles is preferably in the range of 80 to 150 nm, preferably 90 to 120 nm. The range of is more preferable.

  Moreover, since it is preferable that the film thickness of the antireflection layer comprising the porous silica particles (A) is more uniform, it is preferable that the particle size distribution of the porous silica particles is narrow. Therefore, the coefficient of variation (CV), which is an index indicating the particle size distribution of the porous silica particles (A), is in the range of 0 to 40%, more preferably in the range of 0 to 35%. Further, considering the ease of production of the porous silica particles (A), the lower limit of the coefficient of variation is preferably 5%, more preferably 10%, further preferably 15%, and particularly preferably 20%. The variation coefficient is calculated by the following formula (1), and the standard deviation in the following formula (1) is calculated by the following formula (2). In the following formula (2), d84% represents the 84% diameter in the volume particle size distribution, and d16% represents the 16% diameter in the volume particle size distribution.

  Examples of the method for producing the porous silica particles (A) having the volume average diameter and coefficient of variation as described above include hydrolysis of tetraalkoxysilane in water and alcohol using ammonia as a catalyst in the presence of alkylamine. And a method of obtaining a porous silica particle by a condensation reaction.

  Examples of the tetraalkoxysilane used as the raw material for the porous silica particles (A) include tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane. Among these, tetramethoxysilane is preferable because of its high reactivity. These tetraalkoxysilanes can be used alone or in combination of two or more.

  As the alkylamine used in the production of the porous silica particles (A), an amine compound having an alkyl group having 6 to 18 carbon atoms is preferable. Specific examples include octylamine, decylamine, laurylamine, tetradecylamine, oleylamine and the like. These alkylamines can be used alone or in combination of two or more. Since this alkylamine functions as a so-called template for creating pores on the surface of the silica particles, the number and size of the pores can be controlled by the type and amount of addition. Alkylamine also acts as a catalyst for hydrolysis and condensation reaction of tetraalkoxysilane together with ammonia described later.

  Ammonia used in the production of the porous silica particles (A) acts as a catalyst for the hydrolysis and condensation reaction of tetraalkoxysilane. The ammonia to be used may be added as aqueous ammonia or ammonia may be introduced into the reaction solution in the form of a gas. However, it is preferable to use aqueous ammonia because the amount used can be easily controlled.

  As the alcohol used as a solvent in the production of the porous silica particles (A), those miscible with water are preferable. Furthermore, from the viewpoint of preventing the reaction system from becoming complicated due to the exchange reaction between the alkoxysilane and the alcohol, those having the same number of carbon atoms as the alkoxy sites of the tetraalkoxysilane used are particularly preferred. Specific examples include methanol, ethanol, propanol and the like.

  As water used as a solvent in the production of the porous silica particles (A), it is preferable to use pure water in order to avoid impurities from entering the reaction system as much as possible.

  A method for producing porous silica particles (A) using the above materials will be described. The method for producing the porous silica particles (A) of the present invention preferably undergoes the following steps. Moreover, you may add the process of neutralizing an alkylamine and residual ammonia using an acidic compound between the processes 2 and 3.

(Process 1)
Hydrolysis and condensation process of tetraalkoxysilane (process 2)
Silica particle washing step (step 3)
Silica particle drying step (step 4)
Firing process of silica particles

  The above step 1 is a step of forming silica particles by hydrolyzing and condensing tetraalkoxysilane. In this step, a method of preparing the following two liquids A and B and injecting the liquid A into the liquid B while stirring the liquid B is preferable.

(Liquid A)
Liquid in which tetraalkoxysilane, alkylamine and alcohol are uniformly mixed (liquid B)
Liquid in which ammonia water, alcohol and water are mixed uniformly

  The ratio of each component of the liquid A is such that the molar ratio of tetraalkoxysilane and alkylamine is in the range of 1 / 0.05 to 1/5, the pores are on the surface, and the primary particles are This is preferable for obtaining spherical particles.

  The ratio of each component in the liquid B is such that the molar ratio of ammonia to water is in the range of 1/1 to 1/20, the particles have pores on the surface, and the primary particles are spherical. It is preferable to obtain Furthermore, since the reaction operation can be facilitated using aqueous ammonia, the molar ratio of ammonia to water is more preferably from 1 / 2.5 to 1/20.

  The ratio of the liquid A to the liquid B is such that the molar ratio of tetraalkoxysilane to ammonia is in the range of 1 / 0.2 to 1/10, and has pores on the surface and the volume of primary particles. It is preferable for obtaining particles having an average diameter in the range of 80 to 150 nm and a spherical shape.

  The temperature at the time of mixing the liquid A and the liquid B is preferably in the range of 5 to 80 ° C. in order to obtain solubility of the reaction raw material in the reaction system and particles in which the primary particles are spherical.

  The time for injecting the A liquid into the B liquid is preferably in the range of 0 to 240 minutes. Here, 0 minutes represents that the A liquid is charged into the B liquid all at once. Further, after the injection of the liquid A, it is preferable that the reaction is further stirred for 10 minutes or more in a temperature range of 5 to 80 ° C. By this step 1, silica particles that are the basis of the porous silica particles are obtained.

  In Step 2, the silica particles obtained in Step 1 are washed. In step 2, for example, first, silica particles are centrifuged from the reaction solution obtained in step 1, and the silica particles are taken out. Alcohol is added to the silica particles and stirred to form a suspension, and the suspension is centrifuged to extract the silica particles. By performing this step several times, silica particles obtained with alcohol are washed. The alcohol used at this time is preferably the same type as the alcohol used in the preparation of the liquid A and liquid B. In addition, as a method of taking out silica particles from a reaction solution and alcohol suspension, it is not restricted to centrifugation, For example, you may use ultrafiltration. Moreover, you may implement an washing | cleaning process continuously using an ultrafiltration apparatus.

  Since the alkylamine remains in the silica particles washed in step 2, it may be extracted and washed. By extracting and washing, it is possible to prevent the particles from being destroyed when the alkylamine is removed in the subsequent baking step 4. In this step, it is preferable to use an acid to facilitate extraction of the alkylamine. In this case, examples of the acid used include hydrochloric acid, nitric acid, sulfuric acid, and acetic acid. Among these acids, inorganic acids are preferable because the neutralized salt is water-soluble.

  Moreover, when extracting an alkylamine with an acid, it is preferable to carry out in presence of alcohol other than water. In this case, the alcohol used is preferably the same type as the alcohol used in the liquid A and liquid B. Furthermore, the extraction of the alkylamine is preferably performed by heating, and the temperature range is preferably near the boiling point of the alcohol used because of high extraction efficiency.

  In step 3, the solvent is removed from the silica particles washed in step 2 by centrifugation and then dried. The range of 60-150 degreeC is preferable and, as for the drying temperature in the drying process of the process 3, the range of 80-130 degreeC is more preferable.

  In order to remove all organic substances remaining in the silica particles dried in Step 3, the firing step in Step 4 is performed. As the conditions for the firing step, the firing temperature is preferably in the range of 400 to 1,000 ° C, more preferably in the range of 500 to 800 ° C. Moreover, as baking time, it is preferable that it is 30 minutes or more, and it is more preferable that it is 1 hour or more. By performing this firing step, all the organic matter remaining on the silica particles can be removed, so that the porous silica particles (A) having pores on the surface of the silica particles can be obtained.

  If the particles are aggregated after firing, it is preferably pulverized. As a pulverizer used for pulverization, a ball mill, a bead mill, a colloid mill, a conical mill, a disk mill, an edge mill, a milling mill, a hammer mill, a mortar, a pellet mill, a dry or wet jet mill, a vertical axis impactor (VSI) mill, a wheelie mill, A roller mill etc. are mentioned. Among these, a wet jet mill capable of efficiently performing the surface modification of the porous silica particles (A) and the pulverization of the particles described later is preferable.

  The porous silica particles (A) used in the present invention are those obtained by surface modification using a silazane compound as a surface modifier. By this surface modification, the hydroxyl group of the silanol group present on the surface of the porous silica particle (A) can be surface-modified with a silazane compound to replace the hydrophobic group. Examples of the silazane compound include hexamethyldisilazane, hexaethyldisilazane, hexamethylcyclotrisilazane, 1,3-diphenyltetramethyldisilazane, 1,1,3,3-tetramethyldisilazane, and the like. .

  Moreover, it is preferable to use a catalyst when the surface of the porous silica particles (A) is modified with a silazane compound. Examples of the catalyst include inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid; organic acids such as oxalic acid, acetic acid, formic acid, methanesulfonic acid and toluenesulfonic acid; inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine And organic bases such as pyridine; metal alkoxides such as triisopropoxyaluminum and tetrabutoxyzirconium. Among these, acid catalysts (inorganic acids and organic acids) are used because the production stability and storage stability of the dispersion of the porous silica particles (A) are improved. Inorganic acids such as hydrochloric acid and sulfuric acid, and organic acids such as methanesulfonic acid, oxalic acid, phthalic acid, malonic acid, and acetic acid are preferable, and acetic acid is particularly preferable.

  Moreover, as a method of performing this surface modification, the method of immersing porous silica in the solution which dissolved the surface modifier in the solvent, and heating as needed is mentioned, for example. Examples of the solvent used for this surface modification include methanol, ethanol, isopropyl alcohol, benzene, toluene, xylene, N, N-dimethylformamide, acetone, methyl ethyl ketone, and methyl isobutyl ketone.

  The amount of the surface modifier used for the surface modification of the porous silica particles (A) is such that the porous silica particles (A) are stable as primary particles without secondary aggregation. Although the silazane compound is in the range of 0.3 to 60 parts by mass with respect to 100 parts by mass of the silica particles, the range of 0.5 to 50 parts by mass is preferable.

  Furthermore, it is preferable to pulverize the agglomerated particles of the porous silica particles (A) at the same time as the above surface modification to obtain a dispersion in a primary particle state.

  The porous silica particles (A) used in the present invention can be obtained through the above steps 1 to 4 and surface modification. The particle shape, volume average diameter, variation coefficient, pore diameter distribution peak and specific surface area of the obtained porous silica particles can be measured by the following measuring method.

[Particle shape]
The particle shape can be confirmed by observation using a field emission scanning electron microscope (FE-SEM) (for example, “JSM6700” manufactured by JEOL Ltd.).

[Volume average diameter and coefficient of variation]
The volume average diameter can be measured using a particle size distribution meter using a laser Doppler method (for example, “Zeta potential / particle size measurement system ELSZ-2” manufactured by Otsuka Electronics Co., Ltd.). The coefficient of variation is obtained by the above formula (1) from the volume average diameter and standard deviation measured with the same apparatus.

[Peak size distribution peak]
The peak of the pore size distribution is a peak value of the obtained pore size distribution that can be measured using a pore distribution measuring device (for example, Shimadzu Corporation “ASAP2020”).

[Specific surface area]
The specific surface area can be measured by a BET method using a pore distribution measuring device (for example, Shimadzu Corporation “ASAP2020”).

By the measurement method described above, the particle shape, average particle diameter, average pore diameter, and specific surface area of the porous silica particles (A) used in the present invention can be measured. The porous silica particles (A) produced through the above steps 1 to 4 have a substantially spherical appearance, and the volume average diameter can be controlled by adjusting the amount of ammonia used. The thing of the range of 150 nm can be obtained. The average pore diameter and specific surface area of the porous silica particles (A) can be controlled by the type and amount of alkylamine used, and the average pore diameter is in the range of 0.3 to 4 nm. About a specific surface area, the thing of the range of 40-900 m < ² > / g is obtained.

  The composition for antireflection film of the present invention contains the porous silica particles (A) and the binder resin (B). Since the mixed layer of the porous silica particles (A) and the binder resin (B) forms a low refractive index layer, the binder resin (B) preferably forms a low refractive index coating film, Specifically, those having a refractive index of 1.30 to 1.60 are preferable. Specific examples of the binder resin (B) include polyvinyl acetate and its copolymer resin, ethylene-acetic acid copolymer resin, vinyl chloride-vinyl acetate copolymer resin, urethane resin, vinyl chloride resin, and chlorinated polypropylene. Solvent-soluble resins such as resins, polyamide resins, acrylic resins, maleic resins, cyclized rubber resins, polyolefin resins, polystyrene resins, ABS resins, polyester resins, nylon resins, polycarbonate resins, cellulose resins, polylactic acid resins A thermosetting resin such as a phenol resin, an unsaturated polyester resin, or an epoxy resin; an active energy ray curable resin; Among these, an active energy ray-curable resin having high productivity is preferable because a coating film can be formed at a relatively low temperature and a coating film can be formed in a short time.

  The active energy ray-curable resin includes an active energy ray-curable resin (b1), which will be described later, and an active energy ray-curable monomer (b2), which may be used alone, It doesn't matter.

  The active energy ray-curable resin (b1) is a urethane (meth) acrylate resin, an unsaturated polyester resin, an epoxy (meth) acrylate resin, a polyester (meth) acrylate resin, an acrylic (meth) acrylate resin, or a resin having a maleimide group. Etc.

  The urethane (meth) acrylate resin used here is a resin having a urethane bond and a (meth) acryloyl group obtained by reacting an aliphatic polyisocyanate compound or an aromatic polyisocyanate compound with a (meth) acrylate compound having a hydroxyl group. Is mentioned.

  Examples of the aliphatic polyisocyanate compound include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl- 1,5-pentane diisocyanate, dodecamethylene diisocyanate, 2-methylpentamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, norbornane diisocyanate, hydrogenated diphenylmethane diisocyanate , Hydrogenated tolylene diisocyanate, hydrogenated xylile Examples include diisocyanate, hydrogenated tetramethylxylylene diisocyanate, cyclohexyl diisocyanate, and the aromatic polyisocyanate compound includes tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, Examples include toridine diisocyanate and p-phenylene diisocyanate.

  On the other hand, examples of the acrylate compound having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 1, Monovalent dihydric alcohols such as 5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, and hydroxypivalate neopentyl glycol mono (meth) acrylate ( Meth) acrylate; trimethylolpropane di (meth) acrylate, ethoxylated trimethylolpropane (meth) acrylate, propoxylated trimethylolpropane di (meth) acrylate, glycerin di (meth) acrylate Mono- or di (meth) acrylates of trivalent alcohols such as relate, bis (2- (meth) acryloyloxyethyl) hydroxyethyl isocyanurate, or hydroxyl groups obtained by modifying some of these alcoholic hydroxyl groups with ε-caprolactone Mono- and di (meth) acrylates having a monofunctional hydroxyl group and tri- or more functional (meth) acryloyl such as pentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, etc. A compound having a group, or a polyfunctional (meth) acrylate having a hydroxyl group obtained by modifying the compound with ε-caprolactone; dipropylene glycol mono (meth) acrylate, diethylene glycol mono (meth) acrylate, poly (Meth) acrylate compounds having an oxyalkylene chain such as propylene glycol mono (meth) acrylate and polyethylene glycol mono (meth) acrylate; polyethylene glycol-polypropylene glycol mono (meth) acrylate, polyoxybutylene-polyoxypropylene mono (meth) (Meth) acrylate compounds having a block structure oxyalkylene chain such as acrylate; random structures such as poly (ethylene glycol-tetramethylene glycol) mono (meth) acrylate and poly (propylene glycol-tetramethylene glycol) mono (meth) acrylate And (meth) acrylate compounds having an oxyalkylene chain.

  The reaction between the aliphatic polyisocyanate compound or the aromatic polyisocyanate compound and the (meth) acrylate compound having a hydroxyl group can be carried out by a conventional method in the presence of a urethanization catalyst. Specific examples of urethanization catalysts that can be used here include amines such as pyridine, pyrrole, triethylamine, diethylamine, and dibutylamine, phosphines such as triphenylphosphine and triethylphosphine, dibutyltin dilaurate, octyltin trilaurate, and octyl. Examples thereof include organotin compounds such as tin diacetate, dibutyltin diacetate, and tin octylate, and organometallic compounds such as zinc octylate.

  Among these urethane (meth) acrylate resins, those obtained by reacting an aliphatic polyisocyanate compound with a (meth) acrylate compound having a hydroxyl group are excellent in transparency of the cured coating film and sensitive to active energy rays. Is preferable since it is excellent in curability. Moreover, as the (meth) acrylate compound having a hydroxyl group, a polyfunctional (meth) acrylate compound having a plurality of (meth) acryloyl groups is preferable because the hardness of the cured coating film is excellent.

  Next, the unsaturated polyester resin is a curable resin obtained by polycondensation of α, β-unsaturated dibasic acid or acid anhydride thereof, aromatic saturated dibasic acid or acid anhydride thereof, and glycols. The α, β-unsaturated dibasic acid or its acid anhydride includes maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, chloromaleic acid, and esters thereof. As aromatic saturated dibasic acid or acid anhydride thereof, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, nitrophthalic acid, tetrahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, halogenated phthalic anhydride and these Examples include esters. Examples of the aliphatic or alicyclic saturated dibasic acid include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, glutaric acid, hexahydrophthalic anhydride, and esters thereof. As glycols, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpropane-1,3-diol, neopentyl glycol, triethylene glycol, Examples include tetraethylene glycol, 1,5-pentanediol, 1,6-hexanediol, bisphenol A, hydrogenated bisphenol A, ethylene glycol carbonate, 2,2-di- (4-hydroxypropoxydiphenyl) propane, and others. In addition, oxides such as ethylene oxide and propylene oxide can be used in the same manner.

  Next, as an epoxy vinyl ester resin, (meth) acrylic acid is reacted with an epoxy group of an epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, or a cresol novolak type epoxy resin. What is obtained is mentioned.

  The resin having a maleimide group includes a bifunctional maleimide urethane compound obtained by urethanizing N-hydroxyethylmaleimide and isophorone diisocyanate, and a bifunctional maleimide ester compound obtained by esterifying maleimide acetic acid and polytetramethylene glycol. Examples thereof include tetrafunctional maleimide ester compounds obtained by esterification of maleimidocaproic acid and a tetraethylene oxide adduct of pentaerythritol, and polyfunctional maleimide ester compounds obtained by esterification of maleimide acetic acid and a polyhydric alcohol compound. These active energy ray-curable resins (b1) can be used alone or in combination of two or more.

  Examples of the active energy ray-curable monomer (b2) include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and a number average molecular weight in the range of 150 to 1,000. Polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di having a number average molecular weight in the range of 150 to 1000 (Meth) acrylate, neopentyl glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol Di (meth) acrylate, hydroxypivalate ester neopentyl glycol di (meth) acrylate, bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythr Tall hexa (meth) acrylate, pentaerythritol tetra (meth) acrylate, trimethylolpropane di (meth) acrylate, dipentaerythritol penta (meth) acrylate, dicyclopentenyl (meth) acrylate, methyl (meth) acrylate , Propyl (meth) acrylate, butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) ) Acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, aliphatic alkyl (meth) acrylate such as isostearyl (meth) acrylate, glycerol (meth) acrylate, 2-hydroxyethyl (meth) Acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, allyl (meth) acrylate, 2-butoxyethyl (meth) acrylate, 2- (diethylamino) ethyl (meth) acrylate, 2- ( Dimethylamino) ethyl (meth) acrylate, γ- (meth) acryloxypropyltrimethoxysilane, 2-methoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxy Propylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydipropylene glycolicol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, Polybutadiene (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol (meth) acrylate, polystyrylethyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopenta Nyl (meth) acrylate, dicyclopentenyl (meth) actyl Rate, isobornyl (meth) acrylate, methoxylated cyclodecatriene (meth) acrylate, phenyl (meth) acrylate; maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide, N-hexylmaleimide N-octylmaleimide, N-dodecylmaleimide, N-stearylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide, 2-maleimidoethyl-ethylcarbonate, 2-maleimidoethyl-propylcarbonate, N-ethyl- (2-maleimide) Ethyl) carbamate, N, N-hexamethylene bismaleimide, polypropylene glycol-bis (3-maleimidopropyl) ether, bis (2-maleimidoethyl) carbonate, 1,4- And maleimides such as dimaleimide cyclohexane.

  Among these, since the hardness of the cured coating film is particularly excellent, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tetra ( A trifunctional or higher polyfunctional (meth) acrylate such as (meth) acrylate is preferred. These active energy ray-curable monomers can be used alone or in combination of two or more.

  The compounding amount of the porous silica particles (A) with respect to the binder resin (B) used in the present invention is such that a single layer of porous silica particles can be formed on the coating film surface of the composition for an antireflection film of the present invention. It may be sufficient and it is preferable to adjust according to the coating amount to the base material of the composition for antireflection films of the present invention. For example, when 4.75 parts by mass of the porous silica particles (A) are added to 100 parts by mass of the binder resin (B), a single layer composed of the porous silica particles (A) is formed on the surface of the hard coat having a thickness of 5 μm at 100 nm. It corresponds to the amount that can be formed.

  Examples of the base material of an article that can form an antireflection film on the surface thereof using the composition for antireflection film of the present invention include materials made of metal, glass, plastic, etc. May have a smooth surface on which an image is reflected. What has the anti-reflective film formed by coating the said composition for anti-reflective films on at least one surface of these base materials becomes the article | item of this invention.

  The antireflection film of the present invention has an antireflection film formed by coating the antireflection film composition on at least one surface of a base material as a film. Here, the manufacturing method at the time of using active energy ray curable resin for the said binder resin (B) as said composition for anti-reflective films is demonstrated. First, after coating the antireflection film composition on a substrate film, the composition for antireflection film is cured to irradiate with active energy rays to form an antireflection film as a coating film. Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron beams, α rays, β rays, and γ rays. When irradiating ultraviolet rays as active energy rays to form a cured coating film, it is preferable to add a photopolymerization initiator to the active energy ray curable composition to improve curability. Further, if necessary, a photosensitizer can be further added to improve curability. On the other hand, when using ionizing radiation such as electron beam, α ray, β ray, γ ray, etc., it cures quickly without using a photopolymerization initiator or photosensitizer. There is no need to add a sensitizer.

  Examples of the photopolymerization initiator include intramolecular cleavage type photopolymerization initiators and hydrogen abstraction type photopolymerization initiators. Examples of the intramolecular cleavage type photopolymerization initiator include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy. 2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl-phenylketone, 2-methyl-2-morpholino (4-thio) Methylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, 2- (2- Acetophenone compounds such as hydroxyethoxy) ethyl ester; benzoin, benzoy Benzoins such as methyl ether and benzoin isopropyl ether; acylphosphine oxide compounds such as 2,4,6-trimethylbenzoin diphenylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; benzyl and methylphenyl And glyoxyesters.

  On the other hand, examples of the hydrogen abstraction type photopolymerization initiator include benzophenone, methyl 4-phenylbenzophenone, o-benzoylbenzoate, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide. Benzophenone compounds such as acrylated benzophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 3,3′-dimethyl-4-methoxybenzophenone; 2-isopropylthioxanthone, 2,4 A thioxanthone compound such as dimethylthioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; an aminobenzophenone compound such as Michler's ketone and 4,4′-diethylaminobenzophenone; 2-chloro acridone, 2-ethyl anthraquinone, 9,10-phenanthrenequinone, camphorquinone, and the like.

  Examples of the photosensitizer include amines such as aliphatic amines and aromatic amines, ureas such as o-tolylthiourea, sodium diethyldithiophosphate, s-benzylisothiuronium-p-toluenesulfonate, and the like. And sulfur compounds.

  The amount of these photopolymerization initiators and photosensitizers used is preferably 0.01 to 20 parts by mass, and 0.1 to 15% by mass, with respect to 100 parts by mass of the nonvolatile component in the composition for antireflection film. Is more preferable, and 0.3 to 7 parts by mass is even more preferable.

  Furthermore, the composition for an antireflective film of the present invention can be used for adjusting the viscosity and refractive index, adjusting the color tone of the coating film, etc. Various compounding materials for the purpose of adjusting coating properties and coating film properties, such as various organic solvents, acrylic resins, phenol resins, polyester resins, polystyrene resins, urethane resins, urea resins, melamine resins, alkyd resins, epoxy resins, Various resins such as polyamide resin, polycarbonate resin, petroleum resin, fluororesin, various organic or inorganic particles such as PTFE (polytetrafluoroethylene), polyethylene, polypropylene, carbon, titanium oxide, alumina, copper, silica fine particles, polymerization initiation Agent, polymerization inhibitor, antistatic agent, antifoaming agent, viscosity modifier, light-resistant stabilizer, weather-resistant stabilizer, heat-resistant stabilizer, Antioxidant, Rust inhibitor, Slip agent, Wax, Gloss adjuster, Release agent, Compatibilizer, Conductivity adjuster, Pigment, Dye, Dispersant, Dispersion stabilizer, Silicone, Hydrocarbon surfactant, etc. Can be blended.

  Among the above ingredients, the organic solvent is useful for appropriately adjusting the solution viscosity of the composition for an antireflective film of the present invention, and it is particularly easy to adjust the film thickness for thin film coating. It becomes. Examples of the organic solvent that can be used here include aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, isopropanol, and t-butanol; esters such as ethyl acetate and propylene glycol monomethyl ether acetate; Examples thereof include ketones such as methyl isobutyl ketone and cyclohexanone. These solvents can be used alone or in combination of two or more.

  Here, the amount of the organic solvent used varies depending on the intended use and the target film thickness and viscosity, but is preferably in the range of 0.5 to 4 times the mass of the total mass of the curing component.

  As described above, the active energy ray for curing the composition for antireflection film of the present invention is ionizing radiation such as ultraviolet ray, electron beam, α ray, β ray, γ ray, etc., but a specific energy source or hardening. Examples of the apparatus include germicidal lamps, fluorescent lamps for ultraviolet rays, carbon arc, xenon lamps, high pressure mercury lamps for copying, medium or high pressure mercury lamps, ultrahigh pressure mercury lamps, electrodeless lamps, metal halide lamps, ultraviolet rays using natural light as a light source, Or the electron beam by a scanning type and a curtain type electron beam accelerator etc. are mentioned. Since the apparatus is simple, it is preferable to use an apparatus that generates ultraviolet rays.

  The base film used in the antireflection film of the present invention may be a film or a sheet, and the thickness is preferably in the range of 20 to 500 μm. The material of the base film is preferably a highly transparent resin, for example, a polyester resin such as polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate; a polyolefin resin such as polypropylene, polyethylene, or polymethylpentene-1. Resins; Cellulose acetates such as cellulose acetate (diacetyl cellulose, triacetyl cellulose, etc.), cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate, cellulose acetate phthalate, cellulose nitrate, etc .; polymethyl methacrylate, etc. Acrylic resin; Vinyl chloride resin such as polyvinyl chloride and polyvinylidene chloride; Polyvinyl alcohol; Ethylene-vinyl acetate copolymer; Poly Polyethylene; Polysulfone; Polyethersulfone; Polyetheretherketone; Polyimide resin such as polyimide and polyetherimide; Norbornene resin (for example, “ZEONOR” manufactured by Nippon Zeon Co., Ltd.), modified norbornene resin (for example, (“Arton” manufactured by JSR Corporation), cyclic olefin copolymers (for example, “Appel” manufactured by Mitsui Chemicals, Inc.), etc. Further, two or more types of base materials made of these resins are bonded together. May be used.

  Examples of the method for coating the antireflection film composition of the present invention on a substrate include, for example, a gravure coater, roll coater, comma coater, knife coater, air knife coater, curtain coater, kiss coater, shower coater, wheeler coater, and spin coater. , Coating methods using dipping, screen printing, spraying, applicators, bar coaters and the like. Among these, even when a coating apparatus to which pressure such as a gravure coater or a roll coater is applied is used, the porous silica particles (A) used in the present invention are not destroyed. An antireflection film having a stable antireflection property can be obtained without lowering.

  In addition, when an organic solvent is contained in the composition for antireflection film of the present invention, the organic solvent is volatilized after application of the composition for antireflection film to the substrate film and before irradiation with active energy rays. In order to cause the porous silica (A) to segregate on the coating film surface, it is preferable to heat or dry at room temperature. The heat drying conditions are not particularly limited as long as the organic solvent volatilizes, but it is usually preferable to heat dry in a temperature range of 50 to 100 ° C. and a time period of 1 to 10 minutes.

  By operating as described above, the antireflection film of the present invention is obtained.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The characteristic values of the synthesized porous silica particles were measured by the following method.

[Particle shape]
The particle shape was confirmed by observing it at 50,000 times using a field emission scanning electron microscope (FE-SEM) (“JSM6700” manufactured by JEOL Ltd.).

[Volume average diameter and coefficient of variation]
The volume average diameter was measured using a particle size distribution meter (“Zeta potential / particle size measurement system ELSZ-2” manufactured by Otsuka Electronics Co., Ltd.) using a laser Doppler method. In addition, the coefficient of variation was determined by the following formula (1) from the volume average diameter and standard deviation measured with the same apparatus. In addition, the standard deviation in following formula (1) was calculated | required by following formula (2). In the following formula (2), d84% represents the 84% diameter in the volume particle size distribution, and d16% represents the 16% diameter in the volume particle size distribution.

[Peak size distribution peak]
The peak of the pore size distribution was defined as the peak value of the pore distribution obtained by measurement using a pore distribution measuring device (Shimadzu Corporation “ASAP2020”).

[Specific surface area]
The specific surface area was measured by a BET method using a pore distribution measuring apparatus (Shimadzu Corporation “ASAP2020”).

(Preparation Example 1: Synthesis of porous silica particles (1))
A 500 mL four-necked flask equipped with a thermometer and stirring blades was charged with 213.2 g of methanol, 61.3 g of pure water and 27.4 g of 28% by mass ammonia water, and mixed uniformly by stirring (liquid B). Was kept at 20 ° C. In another container, 34.3 g of tetramethoxysilane (hereinafter abbreviated as “TMOS”), 45.1 g of methanol, and 6.5 g of octylamine were uniformly mixed (solution A). While stirring while maintaining the inside of the flask at 20 ° C., was poured into the B liquid over 120 minutes. The reaction was continued at 20 ° C. for 60 minutes after the end of the injection of the liquid A. After completion of the reaction, the reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded and the precipitate was taken out.

200 g of methanol was added to the precipitate obtained above and mixed by stirring to obtain a suspension. This suspension was centrifuged at 10,000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed with methanol. This methanol washing was repeated twice more. The precipitate thus obtained was dried at 120 ° C. for 6 hours to obtain a white powder. The obtained white powder was put into an electric furnace, heated from 25 ° C. to 600 ° C. at a rate of 2 ° C./min in an air atmosphere, and fired at 600 ° C. for 3 hours. After the fired powder was cooled, it was pulverized in a mortar to obtain 12.5 g of white porous silica particles. When the obtained porous silica particles were observed with a field emission scanning electron microscope (FE-SEM), the particle shape was spherical. In addition, the pore diameter distribution peak of the obtained porous silica particles (1) was 1.5 nm, and the specific surface area by the BET method was 43 m ² / g.

  5 g of the porous silica particles obtained above are mixed with 44.5 g of isopropanol, and dispersed using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusyo Co., Ltd.) at an output of 300 W for 5 minutes, and then into the dispersion. Acetic acid 0.5 g and hexamethyldisilazane (hereinafter abbreviated as “HMDS”) 0.5 g are added, and a processing pressure of 130 MPa is applied using a wet jet mill (“Nanojet Val JN-10” manufactured by Joko Co., Ltd.). For 30 minutes. The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of porous silica particles (1) having a solid content of 7.9% by mass.

  The volume average diameter of the porous silica particles (1) in the dispersion of the porous silica particles (1) obtained above was 102 nm, and the coefficient of variation was 28%.

(Synthesis Example 2: Synthesis of porous silica particles (2))
A 500 mL four-necked flask equipped with a thermometer and stirring blades was charged with 213.2 g of methanol, 61.3 g of pure water and 27.4 g of 28% by mass ammonia water, and mixed uniformly by stirring (liquid B). Was kept at 20 ° C. In another container, 34.3 g of TMOS, 45.1 g of methanol, and 39.3 g of decylamine were mixed uniformly (solution A). While keeping the inside of the flask at 20 ° C. and stirring, the liquid A was poured into the liquid B over 120 minutes. The reaction was continued at 20 ° C. for 60 minutes after the end of the injection of the liquid A. After completion of the reaction, the reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded and the precipitate was taken out.

200 g of methanol was added to the precipitate obtained above and mixed by stirring to obtain a suspension. This suspension was centrifuged at 10,000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed with methanol. This methanol washing was repeated twice more. The precipitate thus obtained was dried at 120 ° C. for 6 hours to obtain a white powder. The obtained white powder was put into an electric furnace, heated from 25 ° C. to 600 ° C. at a rate of 2 ° C./min in an air atmosphere, and fired at 600 ° C. for 3 hours. After the fired powder was cooled, it was pulverized in a mortar to obtain 12.1 g of white porous silica particles. When the obtained porous silica particles were observed with a field emission scanning electron microscope (FE-SEM), the particle shape was spherical. In addition, the pore diameter distribution peak of the obtained porous silica particles (2) was 1.8 nm, and the specific surface area by the BET method was 757 m ² / g.

  5 g of the porous silica particles obtained above are mixed with 44.5 g of isopropanol, and dispersed using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusyo Co., Ltd.) at an output of 300 W for 5 minutes, and then into the dispersion. Acetic acid (0.5 g) and HMDS (0.5 g) were added, and the mixture was dispersed for 30 minutes at a treatment pressure of 130 MPa using a wet jet mill (“Nanojet Val JN-10” manufactured by Joko Corporation). The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. After adding 50.0 g of isopropanol to the precipitate and dispersing for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.), Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of porous silica particles (2) having a solid content of 7.8% by mass.

  The volume average diameter of the porous silica particles (2) in the dispersion of the obtained porous silica particles (2) was 148 nm, and the coefficient of variation was 28%.

(Synthesis Example 3: Synthesis of porous silica particles (3))
A 500 mL four-necked flask equipped with a thermometer and stirring blades was charged with 213.2 g of methanol, 61.3 g of pure water and 27.4 g of 28% by mass ammonia water, and mixed uniformly by stirring (liquid B). Was kept at 20 ° C. In another container, 34.3 g of TMOS, 45.1 g of methanol, and 9.3 g of laurylamine were uniformly mixed (solution A). While keeping the inside of the flask at 20 ° C., the liquid A was poured into the liquid B over 120 minutes. The reaction was continued at 20 ° C. for 60 minutes after the end of the injection of the liquid A. After completion of the reaction, the reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded and the precipitate was taken out.

To the precipitate obtained above, 200 g of methanol was added and mixed to obtain a suspension. This suspension was centrifuged at 10,000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed with methanol. This methanol washing was repeated twice more. The precipitate thus obtained was dried at 120 ° C. for 6 hours to obtain a white powder. The obtained white powder was put into an electric furnace, heated from 25 ° C. to 600 ° C. at a rate of 2 ° C./min in an air atmosphere, and fired at 600 ° C. for 3 hours. After the fired powder was cooled, it was pulverized in a mortar to obtain 12 g of white porous silica particles. When the obtained porous silica particles were observed with a field emission scanning electron microscope (FE-SEM), the particle shape was spherical. In addition, the pore diameter distribution peak of the obtained porous silica particles (3) was 1.8 nm, and the specific surface area by the BET method was 216 m ² / g.

  5 g of the porous silica particles obtained above are mixed with 44.5 g of isopropanol, and dispersed using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusyo Co., Ltd.) at an output of 300 W for 5 minutes, and then into the dispersion. Acetic acid (0.5 g) and HMDS (0.5 g) were added, and the mixture was dispersed for 30 minutes at a treatment pressure of 130 MPa using a wet jet mill (“Nanojet Val JN-10” manufactured by Joko Corporation). The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of porous silica particles (3) having a solid content of 7.9% by mass.

  The volume average diameter of the porous silica particles (3) in the dispersion of the obtained porous silica particles (3) was 139 nm, and the coefficient of variation was 22%.

(Synthesis Example 4: Synthesis of porous silica particles (4))
5 g of the fired porous silica particles obtained in Synthesis Example 3 are mixed with 44.5 g of isopropanol, and dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Thereafter, 0.5 g of acetic acid and 2.1 g of HMDS were added to the dispersion, and the mixture was dispersed for 30 minutes at a treatment pressure of 130 MPa using a wet jet mill (“Nanojet Val JN-10” manufactured by Joko Corporation). The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of porous silica particles (4) having a solid content of 8.0% by mass.

  The volume average diameter of the porous silica particles (4) in the dispersion of the obtained porous silica particles (4) was 127 nm, and the coefficient of variation was 32%.

(Synthesis Example 5: Synthesis of porous silica particles (5))
5 g of the fired porous silica particles obtained in Synthesis Example 3 are mixed with 44.5 g of isopropanol, and dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Thereafter, 0.5 g of acetic acid and 0.03 g of HMDS were added to the dispersion, and the mixture was dispersed for 30 minutes at a treatment pressure of 130 MPa using a wet jet mill (“Nanojet Val JN-10” manufactured by Joko Corporation). The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Mfg. Co., Ltd.) to obtain a dispersion of porous silica particles (5) having a solid content of 8.0% by mass.

  The volume average diameter of the porous silica particles (5) in the dispersion of the obtained porous silica particles (5) was 110 nm, and the coefficient of variation was 33%.

(Comparative Synthesis Example 1: Synthesis of silica particles)
A 500 mL four-necked flask equipped with a thermometer and stirring blades was charged with 213.2 g of methanol, 61.3 g of pure water and 27.4 g of 28% by mass ammonia water, and mixed uniformly by stirring (liquid B). Was kept at 20 ° C. In another container, 34.3 g of TMOS and 45.1 g of methanol were mixed uniformly (solution A). While keeping the inside of the flask at 20 ° C. and stirring, the liquid A was poured into the liquid B over 120 minutes. After completion of the injection, the reaction was continued at 20 ° C. for 60 minutes. After completion of the reaction, the reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded and the precipitate was taken out.

  200 g of methanol was added to the precipitate obtained above and mixed by stirring to obtain a suspension. This suspension was centrifuged at 10,000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed with methanol. This methanol washing was repeated twice more. The precipitate thus obtained was dried at 120 ° C. for 6 hours to obtain a white powder. The obtained white powder was put into an electric furnace, heated from 25 ° C. to 600 ° C. at a rate of 2 ° C./min in an air atmosphere, and fired at 600 ° C. for 3 hours. After the fired powder was cooled, it was pulverized in a mortar to obtain 13.3 g of white silica particles. When the obtained particles were observed with a field emission scanning electron microscope (FE-SEM), the particle shape was spherical.

5 g of the silica particles obtained above are mixed with 44.5 g of isopropanol, and dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). 0.5 g and HMDS 0.5 g were added, and the mixture was dispersed for 30 minutes at a treatment pressure of 130 MPa using a wet jet mill (“Nanojet Val JN-10” manufactured by JOHKO INC.). The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of silica particles having a solid content of 8.2% by mass. The silica particles were solid silica having no pores on the surface, and the specific surface area by the BET method was 29 m ² / g.

  The volume average diameter of the silica particles in the dispersion of silica particles obtained above was 118 nm, and the coefficient of variation was 27%.

(Comparative Synthesis Example 2: Surface modification of hollow silica particles)
5 g of hollow silica particles (primary particle diameter 100 nm, porosity 60%, specific surface area 160 m ² / g) are mixed with 44.5 g of isopropanol, and an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.) is used. Then, after dispersing for 5 minutes at an output of 300 W, 0.5 g of acetic acid and 0.5 g of HMDS were added to the dispersion, and 30 wt. Dispersed for minutes. The obtained dispersion was charged into a 200 mL four-necked flask equipped with a thermometer and stirring blades, and heated to reflux for 60 minutes. The reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded to obtain a precipitate. 50 g of isopropanol was added to the precipitate, and the mixture was dispersed for 5 minutes at an output of 300 W using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.). Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of hollow silica particles having a solid content of 7.5% by mass.

  The volume average diameter of the hollow silica particles in the hollow silica particle dispersion obtained above was 196 nm, and the coefficient of variation was 37%. Furthermore, when the obtained hollow silica particles were observed with a field emission scanning electron microscope (FE-SEM), particles in which the aggregates and the shells of the hollow silica particles were broken were observed. Note that the specific surface area of the hollow silica was not measured because the particles were broken.

(Comparative Synthesis Example 3: Synthesis of porous silica particles (6))
A 300 mL four-necked flask equipped with a thermometer and a stirring blade was charged with 68.4 g of n-heptane and 10.7 g of sodium bis-2-ethylhexylsulfosuccinate, dissolved at 25 ° C. with stirring, and then 15% by mass. 20.6 g of colloidal silica aqueous dispersion (“Snowtex 20” manufactured by Nissan Chemical Industries, Ltd.) and 2.9 g of methyltriethoxysilane were charged into the flask. Subsequently, 1.6 g of 28% by mass aqueous ammonia was dropped into the flask over 5 minutes, and stirring was continued at 25 ° C. for 20 hours to obtain a reaction solution. The reaction solution was centrifuged at 12,000 rpm for 30 minutes, and then the supernatant was discarded to obtain a precipitate. After adding 100 g of methanol to the precipitate, using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.) and dispersing for 5 minutes at an output of 300 W, the dispersion was centrifuged at 12,000 rpm for 30 minutes, The supernatant was discarded and a precipitate was obtained. Subsequently, this process was repeated twice to obtain a precipitate. 100 g of pure water is added to the precipitate, and dispersed using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusho Co., Ltd.) for 5 minutes at an output of 300 W, and then centrifuged at 10,000 rpm for 10 minutes to obtain a supernatant. 100 g of a silica particle dispersion having a solid content of 2.5% by mass was obtained. This operation was repeated until the silica particle precipitate disappeared to obtain 2,000 g of a dispersion of silica particles having a solid content of 0.12% by mass.

After 2,000 g of the silica particle dispersion obtained above was concentrated by ultrafiltration until the silica concentration became 3% by mass, methanol was added, the solvent was replaced using ultrafiltration, and the solid content was 2.0. It was set as the methanol dispersion liquid of the silica particle of the mass%. To a 300 mL four-necked flask equipped with a thermometer and a stirring blade, 75 g of a silica particle methanol dispersion, 1.5 g of formic acid and 0.075 g of methyltrimethoxysilane (hereinafter abbreviated as “MTMS”) were added, and 3 Heated to reflux for hours. Thereafter, isopropanol was added and the solvent was replaced by ultrafiltration to obtain an isopropanol dispersion of silica particles. 0.6 g of HMDS was added to an isopropanol dispersion of the silica particles (1.5 g as silica particles), and the mixture was heated to reflux for 4 hours. Subsequently, the solvent was replaced while adding isopropanol using ultrafiltration to obtain a dispersion of surface-modified porous silica particles (6) (solid content: 4.3% by mass). The volume average diameter of the porous silica particles (6) in the dispersion liquid of the obtained porous silica particles (6) was 23 nm. Furthermore, the pore diameter distribution peak of the porous silica particles (6) obtained by drying the dispersion medium from the dispersion liquid at 120 ° C. for 30 minutes is 1.8 nm, and the specific surface area by the BET method is 236 m ² / g. there were.

(Comparative Synthesis Example 4: Synthesis of porous silica (7))
A 500 mL four-necked flask equipped with a thermometer and stirring blades was charged with 213.2 g of methanol, 61.3 g of pure water and 27.4 g of 28% by mass ammonia water, and mixed uniformly by stirring (liquid B). Was kept at 20 ° C. In another container, 34.3 g of TMOS, 45.1 g of methanol, and 9.3 g of laurylamine were uniformly mixed (solution A). While keeping the inside of the flask at 20 ° C., the liquid A was poured into the liquid B over 120 minutes. The reaction was continued at 20 ° C. for 60 minutes after the end of the injection of the liquid A. After completion of the reaction, the reaction solution was centrifuged at 10,000 rpm for 10 minutes, and then the supernatant was discarded and the precipitate was taken out.

  To the precipitate obtained above, 200 g of methanol was added and mixed to obtain a suspension. This suspension was centrifuged at 10,000 rpm for 10 minutes, the supernatant was discarded, and the precipitate was washed with methanol. This methanol washing was repeated twice more. The precipitate thus obtained was dried at 120 ° C. for 6 hours to obtain a white powder. The obtained white powder was put into an electric furnace, heated from 25 ° C. to 600 ° C. at a rate of 2 ° C./min in an air atmosphere, and fired at 600 ° C. for 3 hours. After the fired powder was cooled, it was pulverized in a mortar to obtain 12 g of white porous silica particles. When the obtained porous silica particles were observed with a field emission scanning electron microscope (FE-SEM), the particle shape was spherical.

  5 g of the porous silica particles obtained above are mixed with 44.5 g of isopropanol, dispersed using an ultrasonic homogenizer (“US-600T” manufactured by Nippon Seiki Seisakusyo Co., Ltd.) for 5 minutes at an output of 300 W, and then a wet jet mill. (“Nanojet Val JN-10” manufactured by Joko Co., Ltd.) was used and dispersed at a treatment pressure of 130 MPa for 30 minutes. The resulting dispersion was designated as No. Filtration was performed using 5C filter paper and Kiriyama funnel (manufactured by Kiriyama Seisakusho Co., Ltd.) to obtain a dispersion of porous silica particles (7) having a solid content of 7.9% by mass. The dispersion of the porous silica particles (7) settled immediately after standing.

  The characteristic values of the silica particles obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4 are also shown in Table 1. In Comparative Synthesis Example 4, since the silica particles are aggregated, the characteristic values of the silica particles are not measured.

  Active energy ray-curable compositions containing the various silica particles obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 4 were prepared as follows.

Example 1
722 parts by mass of a dispersion of porous silica particles (1) obtained in Synthesis Example 1 (containing 57 parts by mass of porous silica particles (1)), hexafunctional urethane acrylate (1 mol of isophorone diisocyanate and 2 mol of pentaerythritol 1,200 parts by mass of triacrylate reacted, photopolymerization initiator (“Irgacure 754” manufactured by BASF Japan Ltd.); oxyphenylacetic acid photopolymerization initiator: 2- [2-oxo-2-phenylacetoxyethoxy A mixture of ethyl ester and 2- (2-hydroxyethoxy) ethyl ester) 60 parts by mass and 4,118 parts by mass of isopropanol were uniformly mixed to obtain an antireflection film composition (1).

(Example 2)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 731 parts by mass of the dispersion of porous silica particles (2) obtained in Synthesis Example 2 (porous silica particles) (2) 57 parts by mass) was used in the same manner as in Example 1 except that 4,118 parts by mass of isopropanol were changed to 4,109 parts by mass to obtain an antireflection film composition (2).

(Example 3)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 722 parts by mass of the dispersion of porous silica particles (3) obtained in Synthesis Example 3 (porous silica particles) (3) 9 parts by mass) was used in the same manner as in Example 1 to obtain an antireflection film composition (3).

Example 4
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 713 parts by mass of the dispersion of porous silica particles (4) obtained in Synthesis Example 4 (porous silica particles (4) 57 mass parts contained) was used in the same manner as in Example 1 except that 4,118 parts by mass of isopropanol was changed to 4,127 parts by mass to obtain an antireflection film composition (4).

(Example 5)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 713 parts by mass of the dispersion of porous silica particles (5) obtained in Synthesis Example 5 (porous silica particles) (5) containing 57 parts by mass), except that 4,118 parts by mass of isopropanol was changed to 4,127 parts by mass to obtain the composition for antireflection film (5).

(Comparative Example 1)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 695 parts by mass of the dispersion of silica particles obtained in Comparative Synthesis Example 1 (containing 57 parts by mass of silica particles) was used. The antireflection film composition (6) was obtained in the same manner as in Example 1 except that 4,118 parts by mass of isopropanol was changed to 4,145 parts by mass.

(Comparative Example 2)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 760 parts by mass of the dispersion of hollow silica particles obtained in Comparative Synthesis Example 2 (containing 57 parts by mass of hollow silica particles) ) Was used in the same manner as in Example 1 except that 4,118 parts by mass of isopropanol was changed to 4,080 parts by mass to obtain an antireflection film composition (7).

(Comparative Example 3)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 1326 parts by mass of the dispersion of porous silica particles (6) obtained in Comparative Synthesis Example 3 (porous silica) Anti-reflective coating composition (8) was obtained in the same manner as in Example 1 except that 4118 parts by mass of isopropanol were changed to 3514 parts by mass using 57 parts by mass of particles (6).

(Comparative Example 4)
Instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1), 722 parts by mass of the dispersion of porous silica particles (7) obtained in Comparative Synthesis Example 4 (porous silica) An antireflection film composition (9) was obtained in the same manner as in Example 1 except that 57 parts by mass of particles (7) were used. In this example, the porous silica particles (7) aggregated and settled during the preparation of the active energy ray-curable composition, and a uniform antireflection film composition could not be obtained.

(Comparative Example 5)
The same procedure as in Example 1 was performed, except that 665 parts by mass of isopropanol (total of 4,783 parts by mass of isopropanol) was used instead of 722 parts by mass of the dispersion of porous silica particles (1) used in Example (1). An antireflection film composition (10) was obtained.

[Preparation of cured coating film for reflectance measurement]
The antireflective coating compositions (1) to (8) and (10) obtained above were each coated on a black ABS plate having a thickness of 2 mm using a wire bar coater # 22 at 25 ° C. After drying for 1 minute, it dried for 5 minutes with a 60 degreeC dryer. Then, it hardened using the ultraviolet curing device (160 W metal halide lamp, ultraviolet irradiation amount 2kJ / m < ² > under an air atmosphere), and produced the cured coating film on the black ABS board. In addition, about the composition for antireflection films (9) obtained by the comparative example 4, since the porous silica particle in a composition aggregated and settled, preparation of a cured coating film was not performed.

[Measurement of reflectance]
About the cured coating film obtained above, a spectrophotometer (“U-4100 type” manufactured by Hitachi High-Technologies Corporation) is used to scan a start wavelength of 800 nm to an end wavelength of 350 nm at a scan speed of 300 nm / min, and a sampling interval. The reflectance was measured under the measurement condition of 0.50 nm. In addition, the reflectance was a portion (bottom) having the lowest reflectance. The measurement results of the reflectance are shown in Table 2.

[Preparation of antireflection film for cross-sectional observation]
The antireflective coating compositions (1) to (8) and (10) obtained above are each formed on a surface-adhesive-treated polyethylene terephthalate film (hereinafter abbreviated as “PET film”) having a thickness of 188 μm. After coating with a wire bar coater # 22 and drying at 25 ° C. for 1 minute, it was dried with a dryer at 60 ° C. for 5 minutes. Then, it was cured using an ultraviolet curing device (in an air atmosphere, a metal halide lamp, an ultraviolet irradiation amount of ² kJ / m ² ) to produce an antireflection film. In addition, about the composition for antireflection films (9) obtained by the comparative example 4, since the porous silica particle in a composition aggregated, preparation of a cured coating film was not performed.

[Section observation of antireflection film]
An anti-thin film obtained above is made into an ultrathin section with an ultramicrotome, and a transmission electron microscope (“JEM-2200FS” manufactured by JEOL Ltd.) is used, and the acceleration voltage is 200 kV, 50,000 times or 100,000 times. Observed at. The observation results were as follows.

(Section observation result of antireflection film using composition (1) for antireflection film)
On the surface opposite to the PET film (base material), a layer in which the porous silica particles (1) were arranged in a substantially single layer was formed with a thickness of about 100 nm.

(Cross-sectional observation result of antireflection film using composition (2) for antireflection film)
On the surface opposite to the PET film (substrate), a layer in which the porous silica particles (2) were arranged in a substantially single layer was formed with a thickness of about 150 nm. A cross-sectional photograph is shown in FIG. The left side of the photograph is the substrate side.

(Result of cross-sectional observation of antireflection film using composition (3) for antireflection film)
On the surface opposite to the PET film (substrate), a layer in which the porous silica particles (3) were arranged in a substantially single layer was formed with a thickness of about 140 nm. A cross-sectional photograph is shown in FIG. The left side of the photograph is the substrate side.

(Section observation result of antireflection film using composition (4) for antireflection film)
On the surface opposite to the PET film (substrate), a layer in which porous silica particles (4) were arranged in a substantially single layer was formed with a thickness of about 140 nm. A cross-sectional photograph is shown in FIG. The right side of the photograph is the base material side.

(Section observation result of antireflection film using composition (5) for antireflection film)
On the surface opposite to the PET film (substrate), a layer in which porous silica particles (5) were arranged in a substantially single layer was formed with a thickness of about 140 nm. A cross-sectional photograph is shown in FIG. The left side of the photograph is the substrate side.

(Results of cross-sectional observation of antireflection film using composition (6) for antireflection film)
On the surface opposite to the PET film (base material), a layer in which silica particles were arranged in a substantially single layer was formed with a thickness of about 120 nm.

(Result of cross-sectional observation of antireflection film using composition (7) for antireflection film)
The layer on which the hollow silica particles segregated on the surface opposite to the PET film (base material) was formed with a thickness of 200 to 500 nm, although the thickness was different depending on the location. Also, many particles aggregated or broken in the coating film. A cross-sectional photograph is shown in FIG. The left side of the photograph is the substrate side.

(Results of cross-sectional observation of antireflection film using composition (8) for antireflection film)
The layer on which the porous silica particles (6) are segregated on the surface opposite to the PET film (base material) is formed with a thickness of about 20 to 75 nm, although the thickness varies depending on the location. On the outermost surface of the far coating film, a layer in which silica particles were arranged in a single layer was formed with a thickness of about 20 nm.

(Results of cross-sectional observation of antireflection film using composition for antireflection film (10))
A homogeneous coating film was formed on the PET film (substrate).

  From the above results, the reflectance of the cured coating film corresponding to the antireflection layer of the antireflection film using the antireflection film compositions (1) to (5) of Examples 1 to 5 of the present invention is 3.0. It was found to be -3.4%, lower than those of Comparative Examples 1-3 and 5, 3.7-4.2%. In addition, as a reason for this low reflection, from the observation of the cross section of the coating film, the low refractive index layer is porous silica having a thickness of 100 to 150 nm, which is near 100 nm, which is said to be able to efficiently realize antireflection. It was found that a low refractive index layer in which one layer of particles was arranged was formed.

  On the other hand, Comparative Example 1 is an example using solid silica particles having no pores on the surface of the silica particles, but a layer having a thickness of about 120 nm in which silica particles are arranged in a single layer was formed on the coating film surface. The reflectivity was as high as 3.7%.

  Comparative Example 2 is an example using hollow silica particles, but it was found that there was a problem that the shell of hollow silica particles was broken when dispersed by a wet jet mill in order to peptize the aggregation of silica particles. . Since the hollow silica particles do not show a low refractive index due to destruction of the shell of the hollow silica particles, the reflectance was as high as 4.0%.

  Comparative Example 3 is an example using 23 nm which is lower than 80 nm which is the lower limit of the volume average diameter of the porous silica particles used in the present invention, but the thickness of the porous silica particles is segregated on the coating film surface. It was found that there was a problem that the thickness was about 20 to 75 nm and the thickness was greatly different depending on the location. Also, the reflectance was as high as 4.0%.

  Since Comparative Example 5 did not use a low refractive index material such as porous silica particles, the reflectance was as high as 4.2%.

Claims (9)

  For an antireflection film having a volume average diameter of 80 to 150 nm, a coefficient of variation of 0 to 40%, and containing porous silica particles (A) having a pore on the surface and a binder resin (B) The porous silica particles are surface-modified with a silazane compound (C), and the silazane compound (C) is added in an amount of 0.3 to 60 with respect to 100 parts by mass of the porous silica particles (A). A composition for an antireflective film, which is modified with parts by mass.   The composition for antireflection film according to claim 1, wherein the silazane compound (C) is hexamethyldisilazane.   The composition for antireflection film according to claim 1 or 2, wherein the porous silica particles are obtained by hydrolysis and condensation reaction of tetraalkoxysilane in water and alcohol in the presence of alkylamine and ammonia. object.   The composition for an antireflection film according to claim 3, wherein the alkylamine is an amine compound having an alkyl group having 6 to 18 carbon atoms.   The composition for antireflection films according to claim 3 or 4, wherein the alcohol is at least one alcohol selected from the group consisting of methanol, ethanol and propanol.   The composition for an antireflection film according to any one of claims 3 to 5, wherein the tetraalkoxysilane is a tetraalkoxysilane that is at least one selected from the group consisting of tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane. object.   A liquid (B liquid) in which ammonia water, alcohol and water are uniformly mixed is injected into a liquid (liquid A) in which tetraalkoxysilane, alkylamine and alcohol are uniformly mixed to hydrolyze and condense tetraalkoxysilane. The composition for antireflection films according to claim 3, wherein porous silica particles are obtained.   An article having an antireflection film formed by coating the composition for antireflection film according to any one of claims 1 to 7 on a substrate.   An antireflection film comprising an antireflection film formed by coating the composition for antireflection film according to any one of claims 1 to 7 on at least one surface of a base film.