JP2006111782A - Coating material composition and coated article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating material composition capable of forming a coating film having an excellent reflection-preventing performance and high surface strength and having high water resistance. <P>SOLUTION: The coating material composition is formed by including porous particles composed of aerogel and a matrix-forming material. The matrix-forming material comprises (A) a copolymerization hydrolyzate of a hydrolyzable organosilane represented by the general formula (1): SiX<SB>4</SB>(X is a hydrolyzable group) with a hydrolyzable organosilane having a fluorine-substituted alkyl group. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coating material composition used for forming an antireflection coating and the like, and a coated product formed as an antireflection coating by coating this coating material composition.

  The anti-reflective coating formed on the outermost surface of the display has excellent anti-reflective performance, surface strength that prevents scratches (ie scratch resistance), and surface water and oil repellency that can easily remove dirt such as fingerprints. Chemical resistance to various chemicals such as cleaners (ie, antifouling properties) is required.

  When the film refractive index is not taken into consideration, a high surface strength can be obtained by using a UV-curable or EB-curable resin coating material. In general, however, a UV-curable or EB-curable resin has a refractive index. Since it is high, the resin-rich coating cannot obtain antireflection performance, and it is necessary to combine a low refractive index filler such as airgel particles. In order to obtain sufficient antireflection performance with a single layer, it is necessary to increase the ratio of airgel particles. In this case, even if the coating matrix material is a UV curable resin or an EB curable resin, a sufficient surface Strength will not be obtained. In addition, with recent high-definition displays (especially liquid crystal displays), it is necessary to eliminate defects caused by foreign matter such as dust in the antireflection coating as much as possible. However, UV-curable and EB-curable resins are diluted after coating. Even if the solvent evaporates, it is in a wet and wet state until UV or EB is irradiated, so that foreign matters such as dust are likely to adhere. For this reason, it is necessary to maintain the cleanliness of the coating zone as well as the entire drying zone, which requires large-scale equipment.

  In order to reduce the area of the drying zone that maintains the cleanliness, a thermosetting resin is preferable as the matrix forming material. However, since a general organic thermosetting resin has a high refractive index, the same as above. It is not possible to obtain a sufficient surface hardness. In addition, the refractive index of fluororesins typified by perfluororesins is as low as less than 1.40. However, the film strength is reduced due to the resin itself, so that a composite with an acrylic resin is required to obtain strength. As a result, the refractive index increases, and eventually it is difficult to achieve both sufficient antireflection performance and surface strength.

On the other hand, a hydrolyzate obtained by hydrolyzing a hydrolyzable organosilane represented by the chemical formula of SiX ₄ (X is a hydrolyzable group) has a lower film refractive index than a general organic resin such as an acrylic resin. In addition, it is a matrix forming material that can be expected to have a coating with excellent mechanical strength. For this reason, when this hydrolyzable organosilane hydrolyzate is used as a matrix-forming material, the ratio of the airgel particles can be reduced as compared with other general organic resins when forming a film in which airgel particles are combined. It is easy to form a film having high surface strength (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 2003-216061

  However, airgel particles, particularly silica airgel particles, are likely to deteriorate due to moisture absorption, and the surface of the cured coating containing the airgel particles has a problem with water resistance.

  The present invention has been made in view of the above points, and provides a coating material composition and a coated product that can form a coating film having excellent antireflection performance and high surface strength and having high water resistance. It is intended to provide.

The coating material composition according to claim 1 of the present invention is a coating material composition containing porous particles made of aerogel and a matrix forming material, and the matrix forming material comprises It is characterized by containing a decomposition product.
(A) The general formula is SiX ₄ (X is a hydrolyzable group) (1)
Copolymerized hydrolyzate of a hydrolyzable organosilane represented by the formula (1) and a hydrolyzable organosilane having a fluorine-substituted alkyl group. The invention of claim 2 provides the matrix-forming material according to claim 1 with the above formula (1). It contains the hydrolyzate (B) obtained by hydrolyzing the hydrolyzable organosilane represented by this.

  The invention of claim 3 is the invention according to claim 1 or 2, wherein the porous particles made of airgel are subjected to hydrolysis polymerization by mixing alkyl silicate with a solvent, water and a hydrolysis polymerization catalyst, and then the solvent is removed by drying. Silica airgel particles obtained in this manner.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the porous particles made of aerogel are hydrolyzed by mixing alkyl silicate together with a solvent, water and a hydrolytic polymerization catalyst, before gelation. Silica airgel particles having an aggregate average particle diameter of 10 nm or more and 100 nm or less, obtained by removing a solvent by drying from an organosilica sol stabilized by dilution or pH adjustment.

  Further, the invention of claim 5 is the method according to any one of claims 1 to 4, wherein the porous particles made of aerogel are hydrolyzed by mixing alkyl silicate together with a solvent, water and an alkaline hydrolysis polymerization catalyst, and gelled. Particles dispersed in an organosilica sol obtained by prior stabilization by dilution or pH adjustment, the aggregate average particle diameter of which is 10 nm or more and 100 nm or less, and a coating film is applied to form a cured film The silica airgel particles are formed into a porous body by removing the solvent simultaneously with drying at the time of forming the particles.

  A coated article according to a sixth aspect of the present invention is characterized in that a cured film of the coating material composition according to any one of the first to fifth aspects is provided on a surface of a base material.

  A cured film having a low refractive index can be formed by using the copolymer hydrolyzate of (A) as a matrix-forming material, and the refractive index is low and excellent antireflection performance even if the amount of airgel particles is reduced. A cured film having a high surface strength can be formed. And the surface of the cured film can be formed hydrophobic by the fluorine component contained in the copolymer hydrolyzate of (A), and the water resistance of the cured film containing porous particles made of airgel is improved. Is something that can be done.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The coating material composition according to the present invention is formed by mixing matrix forming material and porous particles made of airgel. First, the matrix forming material will be described.

  In the present invention, the matrix-forming material contains the copolymerized hydrolyzate (A) as an essential component. The copolymer hydrolyzate (A) is a copolymer hydrolyzate of a hydrolyzable organosilane and a hydrolyzable organosilane having a fluorine-substituted alkyl group.

As hydrolyzable organosilane,
The general formula is SiX ₄ (X is a hydrolyzable group) (1)
The tetrafunctional hydrolyzable organosilane represented by these can be used. Examples of the tetrafunctional hydrolyzable organosilane include a tetrafunctional organoalkoxysilane represented by the following formula (2).

Si (OR) ₄ (2)
“R” in the alkoxyl group “OR” in the formula (2) is not particularly limited as long as it is a monovalent hydrocarbon group, but a monovalent hydrocarbon group having 1 to 8 carbon atoms is preferable. Examples thereof include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a peptyl group, and an octyl group. Among the alkyl groups contained in the alkoxide group, those having 3 or more carbon atoms may be linear such as n-propyl group, n-butyl group, isopropyl group, It may have a branch such as an isobutyl group or a t-butyl group.

  As the hydrolyzable group X of the tetrafunctional hydrolyzable organosilane, in addition to the above alkoxyl group, an acetoxy group, an oxime group (—O—N═C—R (R ′)), an enoxy group (—O—) C (R) = C (R ′) R ″), amino group, aminoxy group (—O—N (R) R ′), amide group (—N (R) —C (═O) —R ′) ( In these groups, R, R ′, and R ″ are each independently, for example, a hydrogen atom or a monovalent hydrocarbon group), halogen, and the like.

  Moreover, as a fluorine-substituted alkyl group containing hydrolyzable organosilane, what has a structural unit represented by following formula (3)-(5) is suitable.

(In the formula, R ¹ represents a fluoroalkyl group or perfluoroalkyl group having ¹ to 16 carbon atoms, and R ² represents an alkyl group, halogenated alkyl group, aryl group, alkylaryl group, arylalkyl having 1 to 16 carbon atoms. A group, an alkenyl group, an alkoxy group, a hydrogen atom or a halogen atom, X represents — (C _a H _b F _c ) —, a represents an integer of 1 to 12, b + c represents 2a, and b represents 0 And an integer of ˜24, c is an integer of 0 to 24. Such X is preferably a group having a fluoroalkylene group and an alkylene group.
A hydrolyzable organosilane and a hydrolyzable organosilane having a fluorine-substituted alkyl group are mixed, hydrolyzed and copolymerized to obtain a copolymer hydrolyzate (A). The mixing ratio (copolymerization ratio) of the hydrolyzable organosilane and the hydrolyzable organosilane having a fluorine-substituted alkyl group is not particularly limited, but is a mass ratio in terms of a condensation compound. A hydrolyzable organosilane having a fluorine-substituted alkyl group is preferably in the range of 99/1 to 50/50. The weight average molecular weight of the copolymer hydrolyzate (A) is not particularly limited, but is preferably in the range of 200 to 5,000. If it is less than 200, the film-forming ability is inferior. Conversely, if it exceeds 5000, the film strength may be lowered.

  In the present invention, a hydrolyzate (B) can be contained as a matrix-forming material in addition to the copolymerized hydrolyzate (A). This hydrolyzate (B) is a tetrafunctional hydrolyzate (tetrafunctional silicone resin) obtained by hydrolyzing the tetrafunctional hydrolyzable organosilane represented by the above formula (1). Examples of the decomposable organosilane include the tetrafunctional organoalkoxysilane of the above formula (2).

  And in preparing the hydrolyzate (B) which is a tetrafunctional silicone resin, it can be carried out by hydrolyzing (including partial hydrolysis) a tetrafunctional hydrolyzable organosilane such as a tetrafunctional organoalkoxysilane. it can. Here, the weight average molecular weight of the hydrolyzate (B) which is the resulting tetrafunctional silicone resin is not particularly limited, but in order to obtain the mechanical strength of the cured coating, the weight average molecular weight is 200 to 2000. It is preferable that it exists in the range. If the weight average molecular weight is less than 200, the film forming ability may be inferior, and if it exceeds 2000, the mechanical strength of the cured film may be inferior.

  Silicone diol (C) can further be contained as a matrix forming material. The silicone diol (C) used in the present invention is a dimethyl type silicone diol represented by the following formula (6).

  In the above formula (6), the repeating number n of dimethylsiloxane is not particularly limited, but a range of n = 20 to 100 is preferable. If n is less than 20, the effect of reducing the surface friction resistance described later is reduced. Conversely, if n is more than 100, the compatibility with other matrix forming materials tends to deteriorate, and the transparency of the cured film is reduced. There is a risk of adversely affecting the appearance and uneven appearance of the cured film.

  Next, porous particles made of aerogel will be described. Examples of the porous particles made of aerogel include silica airgel particles, composite airgel particles such as silica / alumina airgel, and organic airgel particles such as melamine airgel. Silica aerogel, for example, as described in U.S. Pat. Nos. 4,402,827, 4,432,956 and 4,610,863, is an alkyl silicate (also referred to as alkoxysilane, silicon alkoxide) as a solvent, water, It is obtained by mixing together with a hydrolysis polymerization catalyst to cause hydrolysis / polymerization reaction, and then drying and removing the solvent. The drying method is preferably supercritical drying. That is, a wet gel compound composed of a silica skeleton obtained by hydrolysis and polymerization reaction is dispersed in a solvent (dispersion medium) such as alcohol or carbon dioxide, and is supercritical above the critical point of the solvent. It can be dried in a state. In supercritical drying, for example, a gel compound is immersed in liquefied carbon dioxide, and all or part of the solvent previously contained in the gel compound is replaced with liquefied carbon dioxide having a lower critical point than that solvent. Thereafter, it can be carried out by drying under supercritical conditions of a single system of carbon dioxide or a mixed system of carbon dioxide and a solvent.

  In producing silica aerogel, as disclosed in JP-A-5-279011 and JP-A-7-138375, a gel-like compound obtained as described above by hydrolysis / polymerization reaction of alkyl silicate It is preferable to impart hydrophobicity to the silica airgel by hydrophobizing. Thus, the hydrophobic silica aerogel to which hydrophobicity is imparted can prevent moisture, water and the like from entering, and can prevent the performance of the silica aerogel such as the refractive index and light transmittance from deteriorating. This hydrophobization treatment step can be performed before or during supercritical drying of the gel compound.

  The hydrophobizing treatment is performed by reacting the hydroxyl group of the silanol group present on the surface of the gel compound with the functional group of the hydrophobizing agent and replacing the silanol group with the hydrophobic group of the hydrophobizing agent. As a method for performing the hydrophobization treatment, for example, the gel is immersed in a hydrophobization treatment solution in which the hydrophobization treatment agent is dissolved in a solvent, and the hydrophobization treatment agent is permeated into the gel by mixing or the like. There is a method in which the hydrophobization reaction is performed by heating accordingly. Examples of the solvent used for the hydrophobizing treatment include methanol, ethanol, isopropanol, xylene, toluene, benzene, N, N-dimethylformamide, hexamethyldisiloxane and the like. The solvent is not limited to these as long as the hydrophobizing agent is easily dissolved and can be replaced with the solvent contained in the gel before the hydrophobizing treatment.

  When supercritical drying is performed in a step after the hydrophobizing treatment, the solvent used for the hydrophobizing treatment is a medium that is easily supercritically dried (for example, methanol, ethanol, isopropanol, liquid carbon dioxide, etc.), or Those that can be substituted are preferred. Examples of hydrophobizing agents include hexamethyldisilazane, hexamethyldisiloxane, trimethylmethoxysilane, dimethyldimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, trimethylethoxysilane, dimethyldiethoxysilane, and methyltriethoxysilane. Can be mentioned.

  Silica airgel particles can be obtained by grinding a dry bulk of silica airgel. However, when the coating is formed as an antireflection coating or the like as in the present invention, the thickness of the cured coating is as thin as about 100 nm as described later, and the silica airgel particles have a particle size of about 50 nm. However, when the bulk is obtained by pulverizing, it is difficult to form silica airgel particles into fine particles having a particle size of about 50 nm. When the particle size of the silica airgel is large, it is difficult to form a cured film with a uniform film thickness and to reduce the surface roughness of the cured film.

  Therefore, in this case, it is preferable to prepare fine-particle silica airgel particles as follows. First, an organosilica sol is prepared by mixing an alkyl silicate with a solvent, water and a hydrolysis polymerization catalyst, followed by hydrolysis and polymerization. As the solvent, for example, alcohol such as methanol, and as the hydrolysis polymerization catalyst, for example, ammonia can be used. Next, before the gelation occurs, the organosilica sol is diluted with a solvent, or the pH of the organosilica sol is adjusted, thereby suppressing the growth of silica polymer particles and stabilizing the organosilica sol.

  Here, as a method of stabilizing the organosilica sol by dilution, for example, a solvent in which the initially prepared organosilica sol such as ethanol, 2-propanol, acetone or the like is easily and uniformly dissolved is used, and a dilution ratio of at least 2 times or more is used. The method of diluting to become can be mentioned. At this time, when the solvent contained in the initially prepared organosilica sol is an alcohol, and alcohol is used as a diluting solvent, the type of alcohol is not particularly limited, but it is more carbon than the alcohol contained in the initially prepared organosilica sol. It is preferable to dilute with a large number of alcohols. This is because the alcohol substitution reaction contained in the silica sol has a high effect of suppressing the hydrolysis polymerization reaction with dilution.

  On the other hand, as a method of stabilizing the organosilica sol by adjusting the pH, for example, an acid is added when the hydrolysis polymerization catalyst in the first prepared organosilica sol is alkali, and an alkali is added when the hydrolysis catalyst is acid. And a method of adjusting the pH of the organosilica sol to be weakly acidic. With this weak acidity, it is necessary to select a stable pH as appropriate depending on the type of solvent used in the preparation and the amount of water, but a pH of about 3 to 4 is preferred. For example, for the organosilica sol when ammonia is selected as the hydrolysis polymerization catalyst, it is preferable to adjust the pH to 3 to 4 by adding nitric acid or hydrochloric acid, and nitric acid is selected as the hydrolysis polymerization catalyst. In the case of the organosilica sol, it is preferable to adjust the pH to 3 to 4 by adding a weak alkali such as ammonia or sodium hydrogen carbonate.

  Any of the above methods may be selected as a method for stabilizing the organosilica sol, but it is more effective to use dilution and pH adjustment in combination. In addition, the hydrolytic polymerization reaction can be further suppressed by adding an organosilane compound typified by hexamethyldisilazane or trimethylchlorosilane at the same time to hydrophobize the silica airgel fine particles. It can be done.

  Next, porous silica airgel fine particles can be obtained by directly drying the organosilica sol. Silica airgel fine particles preferably have an aggregate average particle size in the range of 10 to 100 nm. When the aggregated particle diameter exceeds 100 nm, it becomes difficult to obtain a uniform film thickness of the cured film as described above and to reduce the surface roughness. On the other hand, when the aggregate average particle size is less than 10 nm, when the coating material composition is prepared by mixing with the matrix-forming material, the matrix-forming material enters the silica airgel particles, and in the dried film, the silica airgel particles May not be a porous body.

  A specific method of drying is to fill the organosilica sol in a high-pressure vessel, replace the solvent in the silica sol with liquefied carbon dioxide gas, then set the temperature to 32 ° C. or higher and 8 MPa or higher, and then reduce the pressure. In this way, the silica silica gel particles can be obtained by drying the organosilica sol. In addition to the above-described dilution method and pH adjustment method, organosilane compounds represented by hexamethyldisilazane and trimethylchlorosilane are added to suppress the polymerization reaction of silica particles. There is also a method of stopping, and this method is advantageous because the silica airgel particles can be simultaneously hydrophobized with an organosilane compound.

  Further, when the coating is formed as an antireflection coating or the like as in the present invention, the cured coating needs to have high transparency with a clear feeling (specifically, it is more preferable to suppress the haze to 0.2% or less). . Therefore, when preparing the coating material composition by adding silica airgel particles to the matrix forming material, it is preferable that the silica airgel particles are uniformly dispersed in the solvent from the beginning before being added to the matrix forming material. In doing so, first, an organosilica sol is prepared by mixing an alkyl silicate with a solvent such as methanol, water, and an alkaline hydrolysis polymerization catalyst such as ammonia, followed by hydrolysis and polymerization. Next, in the same manner as described above, the organosilica sol is diluted with a solvent before gelation occurs, or the pH of the organosilica sol is adjusted to suppress the growth of silica polymer particles, thereby stabilizing the organosilica sol. The thus-stabilized organosilica sol can be used as a silica airgel dispersion and added to the matrix forming material to prepare a coating material composition. At this time, the aggregation average particle diameter of the silica airgel particles in the organosilica sol needs to be smaller than 100 nm and larger than 10 nm. When the aggregate average particle diameter exceeds 100 nm, it becomes difficult to express the characteristics of the cured film as described above. On the other hand, when the aggregate average particle size is less than 10 nm, the matrix-forming material enters the silica airgel particles when mixed with the matrix-forming material to prepare the coating material composition. Airgel particles are no longer porous. By setting the average aggregate particle size to 10 nm or more, it is possible to prevent the matrix forming material from entering the silica airgel particles. And a solvent is removed by drying at the time of apply | coating a coating material composition and forming a film, and a silica airgel particle is formed in a porous body. In the coating material composition according to the present invention, the content of the porous particles made of aerogel is not particularly limited, but is in the range of 5 to 80% by mass in terms of the solid content of the coating material composition. Is preferred. If the content is less than 5% by mass, the effect of reducing the refractive index of the coating film cannot be sufficiently obtained for the purpose of antireflection effect. Conversely, if the content exceeds 80% by mass, it is uniform. It becomes difficult to form a transparent film. Furthermore, since the film formability such as the strength and appearance of the formed coating film is also important for practical use, the content of porous particles made of airgel is required to achieve both easy-to-handle film strength and effective low refractive index effect. Is more preferably in the range of 20 to 50% by mass.

  Then, the coating material composition prepared as described above is applied to the surface of the base material to form a coating, and the coating is dried and cured to form a cured coating having a low refractive index on the surface. Goods can be obtained. The base material to which the coating material composition is applied is not particularly limited, but examples thereof include inorganic base materials typified by glass, metal base materials, organic base materials typified by polycarbonate and polyethylene terephthalate. Examples of the shape of the substrate include a plate shape and a film shape. Furthermore, one or more layers may be formed on the surface of the substrate.

  The method of coating the coating material composition on the surface of the base material is not particularly limited. For example, brush coating, spray coating, dipping (dipping, dip coating), roll coating, flow coating, curtain coating. Various ordinary coating methods such as knife coating, spin coating, table coating, sheet coating, single wafer coating, die coating, and bar coating can be selected.

  Moreover, it is preferable to heat-treat this after drying the coating formed on the surface of the substrate. This heat treatment can further improve the mechanical strength of the cured coating. The temperature during the heat treatment is not particularly limited, but it is preferable to perform the treatment at a relatively low temperature of 100 to 300 ° C. for 5 to 30 minutes. Even if heat treatment is performed at such a low temperature, the same mechanical strength as when heat treatment is performed at a high temperature can be obtained, so that the film forming cost can be reduced, and as in the case of heat treatment at a high temperature. The type of the base material is not limited. In addition, for example, in the case of a glass substrate, since the thermal conductivity is low, it takes time for temperature rise and cooling, and the heat treatment at a high temperature slows down the processing speed, whereas the heat treatment at a low temperature conversely increases the processing speed. It is something that can be done.

  The film thickness of the cured film formed on the surface of the substrate can be appropriately selected according to the intended use and purpose and is not particularly limited, but is preferably in the range of 50 to 150 nm.

  Thus, if the coating material composition according to the present invention is used, a cured film having a low refractive index can be easily formed, which is suitable for antireflection applications. For example, when the refractive index of the base material is 1.60 or less, a cured coating having a refractive index of 1.60 or more is formed on the surface of the base material, and this is used as an intermediate layer. It is effective to form a cured film with the coating material composition according to the present invention. The cured film for forming the intermediate layer can be formed using a known high refractive index material, and if the refractive index of the intermediate layer is 1.60 or more, the coating material composition according to the present invention is used. Thus, the difference in refractive index from the cured film due to the above becomes large, and an antireflection substrate excellent in antireflection performance can be obtained. Moreover, in order to relieve the coloring of the cured film of the antireflection substrate, the intermediate layer may be formed of a plurality of layers having different refractive indexes. Examples of the use for antireflection include the outermost surface of a display, a side mirror of an automobile, a windshield, a side glass, an inner surface of a rear glass, other vehicle glass, and building material glass.

  In forming a cured film having a low refractive index on the surface of the substrate as described above, the copolymer hydrolyzate (A) that forms the matrix forming material contains a fluorine component. Can be formed hydrophobic by this fluorine component, and the water resistance of the cured coating containing airgel particles that easily deteriorate due to moisture absorption can be improved.

  Further, if the coating material composition contains silicone diol as a part of the matrix forming material, the silicone diol can be introduced into the cured film, and the surface frictional resistance of the cured film can be reduced. Therefore, it is possible to reduce the catch on the surface of the cured coating so that scratches are difficult to enter, and to improve the scratch resistance. In particular, the dimethyl type silicon diol described above in the present invention is such that when the coating is formed, the silicone diol is localized on the surface of the coating and does not impair the transparency of the coating (having a low haze ratio). In addition, the dimethyl type silicone diol is excellent in compatibility with the matrix forming material used in the present invention and has reactivity with the silanol group of the matrix forming material, so that it is fixed to the surface of the cured film as a part of the matrix. Yes, the surface of the hardened film is not removed when the surface of the hardened film is wiped, just like when silicone oil (both ends are methyl groups) is mixed. Thus, the scratch resistance can be maintained for a long time.

  Hereinafter, the present invention will be specifically described by way of examples. Unless otherwise specified, all “parts” represent “parts by mass”, and “%” represents “% by mass” except for the reflectance and haze ratio described later. Further, the molecular weight is measured by GPC (gel permeation chromatography), using a standard polystyrene with a calibration curve using HLC8020 manufactured by Tosoh Corporation as a measurement model, and measuring the converted value.

Example 1
A solution in which tetramethoxysilane, methanol, water, and 28% ammonia water were mixed at a ratio of 470: 812: 248: 6 in parts by mass was prepared, and the solution was allowed to gel at room temperature overnight. A wet gel was obtained. This wet gel is put into a high-pressure vessel, and after 7 MPa of liquefied carbon dioxide gas is injected, the temperature is raised to 80 ° C. and the pressure is raised to 16 MPa to bring the inside of the high-pressure vessel into a supercritical state. After replacing the solvent in the container, the pressure was reduced to produce a bulk silica airgel.

  The silica airgel was coarsely pulverized to a particle diameter of several millimeters using a “Feather Mill” manufactured by Hosokawa Micron Corporation, and then further finely pulverized to 50 to 100 nm by a jet mill to produce silica airgel particles.

On the other hand, 356 parts of methanol is added to 166.4 parts of tetraethoxysilane, 14.7 parts of heptadecafluorodecyltriethoxysilane (CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ ), and 18 parts of water and 18 parts of a 0.01N hydrochloric acid aqueous solution (“H ₂ O” / “OR” = 0.5) were mixed and mixed well using a disper. This mixed solution was stirred in a thermostat at 25 ° C. for 2 hours to obtain a fluorine / silicone copolymer hydrolyzate (A) having a weight average molecular weight adjusted to 830 as a matrix-forming material.

  Next, an organosilica sol in which the silica airgel particles produced as described above are dispersed in IPA (isopropanol) is prepared so as to have a silica concentration of 5%, and this is prepared by the above-described fluorine / silicone copolymer hydrolyzate (A). In addition, the silica airgel particles / fluorine / silicone copolymer hydrolyzate (condensation compound equivalent) is blended so that the mass ratio is 50/50 based on the solid content, and then the total solid content is 1%. Dilute with an IPA / butyl acetate / butyl cellosolve mixture (premixed so that 5% of the diluted solution is butyl acetate and 2% of the whole solution is butyl cellosolve), and then dimethyl silicone diol ( A solution obtained by diluting n≈40) of formula (6) with ethyl acetate so as to have a solid content of 1% is obtained by combining silica airgel particles and fluorine / silico. With respect to the sum of the solid content of emissions copolymer hydrolyzate (condensation compound equivalent), the solids content of the dimethyl silicone diols by the addition at 2% to prepare a coating material composition.

This coating material composition was allowed to stand for 1 hour, and then cleaned in advance with a UV-ozone cleaner (excimer lamp “Model H0011” manufactured by USHIO INC.), An acrylic plate (“Delaglass _TM HA” manufactured by Asahi Kasei Co., Treatment, hard coat with a refractive index of 1.52 and a haze of 0.20) is coated with a wire bar coater to form a film with a film thickness of about 100 nm, and the film is heat-treated at 80 ° C. for 1 hour in an oxygen atmosphere. By doing so, a cured film was obtained.

(Example 2)
A solution in which tetramethoxysilane, methanol, water, and 28% ammonia water were mixed at a ratio of 470: 812: 248: 6 by weight was prepared. After the solution was stirred for 1 minute, the pH of the solution was adjusted to 8 by adding nitric acid to the solution and stabilized, and further diluted 2-fold with IPA to prepare an organosilica sol. This silica sol is placed in a high-pressure vessel, and after injecting 7 MPa of liquefied carbon dioxide gas, the temperature is raised to 80 ° C. and the pressure is increased to 16 MPa to bring the inside of the high-pressure vessel into a supercritical state. After replacing the solvent in the inner layer, the pressure was reduced to produce translucent milky white silica airgel particles remaining in the high-pressure vessel.

  A coating material composition was prepared in the same manner as in Example 1 except that the silica airgel particles were used, and the coating material composition was applied in the same manner as in Example 1 and heat-treated. A cured coating was obtained.

(Example 3)
A solution in which tetramethoxysilane, methanol, water, and 28% ammonia water were mixed at a ratio of 470: 812: 248: 6 in parts by mass was prepared. After stirring this solution for 1 minute, 0.2 part by weight of hexamethyldisilazane was added to the solution, and the mixture was stirred and further diluted 2-fold with IPA to prepare an organosilica sol.

  In Example 1, instead of preparing and using silica airgel particles so that the silica concentration is 5%, a coating material composition was prepared in the same manner as in Example 1 except that this organosilica sol was used. Further, this coating material composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

  About the cured film obtained in said Examples 1-3, the minimum reflectance, haze rate, and refractive index were measured, and the performance evaluation of the cured film was performed. The results are shown in Table 1.

(Minimum reflectance)
The minimum reflectance was measured using a spectrophotometer ("U-4100" manufactured by Hitachi, Ltd.).

(Haze rate)
It measured using the haze meter (Nippon Denshoku Industries "NDH2000").

(Refractive index)
The refractive index was derived with a simple ellipsometer (“F20” manufactured by FILMTRICS).

  As can be seen from Table 1, it is confirmed that each of the examples has low reflectivity, haze rate, and refractive index and high performance as an antireflection coating.

Claims (6)

A coating material composition comprising porous particles made of airgel and a matrix-forming material, wherein the matrix-forming material comprises a copolymerized hydrolyzate of the following (A) Composition.
(A) The general formula is SiX ₄ (X is a hydrolyzable group) (1)
Copolymerized hydrolyzate of a hydrolyzable organosilane represented by the formula: and a hydrolyzable organosilane having a fluorine-substituted alkyl group   The coating material composition according to claim 1, wherein the matrix-forming material contains a hydrolyzate (B) obtained by hydrolyzing the hydrolyzable organosilane represented by the formula (1). .   The porous particles made of aerogel are silica airgel particles obtained by mixing an alkyl silicate with a solvent, water and a hydrolysis polymerization catalyst to hydrolyze and then removing the solvent by drying. 3. The coating material composition according to 1 or 2.   Porous particles made of aerogel are mixed with alkyl silicate together with solvent, water and hydrolysis polymerization catalyst to hydrolyze, and the solvent is removed by drying from organosilica sol that has been stabilized by dilution or pH adjustment before gelation. 4. The coating material composition according to claim 1, wherein the silica airgel particles have an aggregate average particle diameter of 10 nm to 100 nm.   In the organosilica sol, the porous particles made of aerogel are obtained by mixing alkyl silicate with solvent, water, alkaline hydrolysis polymerization catalyst, hydrolyzing and stabilizing by dilution or pH adjustment before gelation. Dispersed particles having an aggregate average particle diameter of 10 nm to 100 nm, and formed into a porous body by removing the solvent simultaneously with drying when a coating composition is applied to form a cured film The coating material composition according to any one of claims 1 to 4, wherein the silica airgel particles are used.   A coated article comprising a cured film of the coating material composition according to any one of claims 1 to 5 on a surface of a substrate.