JP2015021029A - Composition, antireflection layer using the same and method for forming the same, glass having the same and solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition which can be coated on glass or the like and has excellent moist heat resistance.SOLUTION: There is provided a composition which comprises: (a) chain silica particles having an average primary particle diameter of 5 to 40 nm; (b) a hydrolysis condensate of organoalkoxysilane represented by the general formula (1), (R)Si(OR)(1) (wherein, Rrepresents hydrogen, an alkyl group, an alkenyl group, an aryl group or a substitution product thereof; Rmay be the same or different and represents an alkyl group, an acyl group, aryl group or a substitution product thereof; and m represents an integer of 0 to 3); (c) a silane compound having a specific structure; and (d) a solvent, wherein the chain silica particles having an average primary particle diameter of 5 to 40 nm is contained in an amount of 50 wt% or more of a total solid content of the composition.

Description

  The present invention relates to a composition and the like used for forming an antireflection layer on a glass surface. In particular, the present invention relates to a composition for forming a coating layer having excellent durability and antireflection function in heat-tempered glass. The present invention also relates to an antireflection layer, a method for forming the antireflection layer, glass on which an antireflection film is formed, and a solar cell module including the glass as a constituent element.

  Currently, heat strengthening is widely applied to cover glass for solar cells, glass for building materials, glass for automobiles, and glass for displays. Such a heat-strengthened glass is given an antireflection effect when applied to each application.

In order to impart an antireflection effect to tempered glass, a method of forming an antireflection layer on the surface by a conventional CVD method has been employed. However, MgF ₂ shows the lowest refractive index among materials to which the CVD method can be applied, but the refractive index is still about 1.38. Therefore, a wet coating method capable of lowering the refractive index than the CVD method is being applied because of the need for high reflection performance and low cost.

  In the case of the wet coating method, a method of curing the coating film at the same time as heat strengthening in a heat strengthening process after applying a siloxane-based antireflection coating composition on the glass surface for the purpose of reducing the process is common.

  For example, Patent Document 1 proposes a siloxane-based antireflection coating composition that cures in a glass semi-melting process after application of the coating composition. Patent Document 2 proposes an antireflection coating composition having excellent substrate adhesion. Further, regarding the improvement of substrate adhesion, Patent Document 3 proposes adding an organosilicon compound having an amic acid structure to a polyimide resin composition.

JP-A-11-292568 JP 2012-505295 A JP-A-9-222729

  In each of the above applications to which tempered glass is applied, it is necessary to clear a durability test represented by a temperature cycle test, a heat and humidity test, and the like. In particular, in a siloxane-based coating composition having hydrolyzability, resistance to moist heat is a problem. For example, in a cover glass for solar cells, particularly severe wet heat resistance is required for long-term outdoor use. However, the conventional antireflection coating composition has insufficient moisture and heat resistance.

  An object of the present invention is to solve the above-mentioned problems and to provide a composition that can be coated on glass or the like and has excellent heat and moisture resistance.

In order to solve the above problems, the present invention has the following configuration. That is, the present invention
(A) chain silica particles having an average primary particle diameter of 5 to 40 nm;
(B) a hydrolytic condensate of an organoalkoxysilane represented by the general formula (1);
(R ¹ ) _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents hydrogen, an alkyl group, an alkenyl group, an aryl group, or a substituted product thereof. R ² may be the same or different, and represents an alkyl group, an acyl group, an aryl group, or a substituted product thereof. m represents an integer of 0 to 3.)
(C) a silane compound represented by the general formula (2) or (3);

(In the general formulas (2) and (3), R ³ may be the same or different and is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, a phenoxy group, or a substituted product thereof. R ⁴ may be the same or different and represents a trivalent hydrocarbon group having 3 to 30 carbon atoms composed of a plurality of atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, and a nitrogen atom. R ⁵ may be the same or different and is a hydrogen atom or a C 1-20 having one or more atoms selected from a carbon atom not containing a silicon atom, a hydrogen atom, an oxygen atom, or a nitrogen atom. Represents a valent hydrocarbon group, and n represents an integer of 1 to 3.)
(D) a solvent;
And (a) a chain silica particle having an average primary particle diameter of 5 to 40 nm is contained in a total solid content of 50 wt% or more.

  When the composition of the present invention is applied to a glass substrate, it can be cured in a heat strengthening process, and the obtained antireflection film has excellent antireflection performance and moisture and heat resistance. Further, even when applied to a substrate having an uneven surface such as embossed glass, it has excellent antireflection performance.

It is a schematic explanatory drawing about a chain | strand-shaped silica particle. It is surface sectional drawing of the embossed glass which concerns on this invention. It is a schematic explanatory drawing of the application | coating state of the liquid to the embossed glass surface which concerns on this invention. It is a schematic explanatory drawing of the solar cell module using the reflection preventing film which concerns on this invention.

The composition of the present invention has the following constitution.
(A) chain silica particles having an average primary particle diameter of 5 to 40 nm;
(B) a hydrolytic condensate of an organoalkoxysilane represented by the general formula (1);
(R ¹ ) _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents hydrogen, an alkyl group, an alkenyl group, an aryl group, or a substituted product thereof. R ² may be the same or different, and represents an alkyl group, an acyl group, an aryl group, or a substituted product thereof. m represents an integer of 0 to 3.)
(C) a silane compound represented by the general formula (2) or (3);

(In the general formulas (2) and (3), R ³ may be the same or different, and an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, a phenyl group, a phenoxy group, or a substituted product thereof. R ⁴ may be the same or different and represents a trivalent hydrocarbon group having 3 to 30 carbon atoms composed of a plurality of atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, and a nitrogen atom. R ⁵ may be the same or different and is a hydrogen atom or a C 1-20 having one or more atoms selected from a carbon atom not containing a silicon atom, a hydrogen atom, an oxygen atom, or a nitrogen atom. Represents a valent hydrocarbon group, and n represents an integer of 1 to 3.)
(D) a solvent;
(A) The chain silica particles having an average primary particle diameter of 5 to 40 nm are contained in an amount of 50 wt% or more in the total solid content. Hereinafter, each component will be described.

(A) Chain silica particles having an average primary particle diameter of 5 to 40 nm The chain silica particles of the present invention are directly bonded by a chemical bond such as a siloxane bond without a plurality of primary particles passing through a joint made of another material. In addition, it refers to a continuous chain shape, which may be a linearly extended shape or a two-dimensionally or three-dimensionally curved shape.

  The average primary particle diameter of the chain silica particles (D, see FIG. 1 which is a schematic explanatory diagram of the chain silica particles) is 5 nm or more, and more preferably 7 nm or more. When D is less than 5 nm, the film obtained from the composition of the present invention is structurally weak and inferior in durability. Further, D is 40 nm or less, and more preferably 30 nm or less. When D exceeds 40 nm, the coating film thickness becomes too thick, and preferable antireflection performance cannot be obtained.

  Here, in the present invention, the average primary particle diameter D is a value measured as follows. A film formed by casting after drying the composition or a film formed using the composition is observed with an electron microscope, and the major axis and minor axis are measured for 30 arbitrary primary particles, respectively, and the average value thereof is the average primary particle diameter. D.

  Since such chain silica particles have large interparticle voids in the deposited state, the use of the particles makes it possible to lower the refractive index of the film obtained from the composition of the present invention.

  Specifically, in order to obtain a good antireflection effect using a single-layer antireflection film, the refractive index of the antireflection film needs to be about ½ of the refractive index of the transparent substrate. There is. Since the refractive index of general optical glass is 1.47 to 1.70, the refractive index of the antireflection film is required to be about 1.21 to 1.30. In this specification, the refractive index is a value at a measurement wavelength of 633 nm unless otherwise specified.

  When only ordinary spherical silica is used, it is difficult to control the refractive index within this range, and in order to reduce the refractive index, it is necessary to increase the content ratio of the particles in the composition. Then, since the content ratio of the matrix structure other than the particles becomes small, durability such as heat and humidity resistance becomes remarkably low. By using chain silica particles, it is possible to obtain a low refractive index film having a refractive index of 1.30 or less while maintaining durability.

  Specific examples of the chain silica particles include “Snowtex (registered trademark) -OUP”, “Snowtex (registered trademark) -UP”, and “Snowtex (registered trademark) PS-M” manufactured by Nissan Chemical Industries, Ltd. "Snowtex (registered trademark) PS-MO", "Snowtex (registered trademark) PS-S", "Snowtex (registered trademark) PS-SO", "IPA-ST-UP", Nippon Shokubai Kasei “Fine Cataloid F-120” manufactured by Kogyo Co., Ltd. and the like can be mentioned.

  In the composition of the present invention, the content of (a) chain silica particles having an average primary particle diameter of 5 to 40 nm in the total solid content is 50 wt% or more, and more preferably 60 wt% or more. If it is less than this range, the refractive index of the film obtained from the composition of the present invention cannot be controlled low, and antireflection performance preferable as an antireflection film for glass cannot be obtained.

  Although it is also preferable to use the chain silica particles and ordinary spherical silica particles in combination as necessary, the content of the chain silica particles in the total solid content needs to be 50 wt% or more.

  Specific examples of spherical silica particles that can be used in combination include “IPA-ST”, “MIBK-ST”, “IPA-ST-L”, “IPA-ST-ZL”, “PGM-ST” manufactured by Nissan Chemical Industries, Ltd. "," Quortron PL-2L "," Quortron PL-1 "," Quortron PL-3 "," Quortron PL-7 "and the like manufactured by Fuso Chemical Industry.

(B) Hydrolysis condensate of organoalkoxysilane represented by the general formula (1) The component (b) serves as a matrix for connecting the particles when forming the coating layer. Although there is no restriction | limiting in particular as content of (b) component in a composition, Since durability, such as heat-and-moisture resistance, will improve if a siloxane ratio increases, it contains as much as possible within the range of 50 wt% or less in the total solid content. It is preferable that The content in the total solid content is preferably 5 wt% or more and 50 wt% or less, and more preferably 7 wt% or more and 40 wt% or less. By being in this range, both low refractive index and durability can be achieved.

The alkyl group, alkenyl group, and aryl group in R ¹ of the general formula (1) may be either unsubstituted or substituted, and can be selected according to the characteristics of the composition.

  Specific examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, n-hexyl group, n-decyl group, trifluoromethyl group, 3, 3 , 3-trifluoropropyl group, 3-glycidoxypropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, [(3-ethyl-3-oxetanyl) methoxy] propyl group, 3-aminopropyl group, A 3-mercaptopropyl group, a 3-isocyanatopropyl group, etc. are mentioned.

  Specific examples of the alkenyl group include a vinyl group, 3-acryloxypropyl group, 3-methacryloxypropyl group and the like.

  Specific examples of the aryl group include phenyl group, tolyl group, p-hydroxyphenyl group, p-styryl group, p-methoxyphenyl group, 1- (p-hydroxyphenyl) ethyl group, 2- (p-hydroxyphenyl). Examples thereof include an ethyl group, 4-hydroxy-5- (p-hydroxyphenylcarbonyloxy) pentyl group, and naphthyl group.

The alkyl group, acyl group and aryl group in R ² of the general formula (1) may be either unsubstituted or substituted, and can be selected according to the characteristics of the composition.

Specific examples of the alkyl group include the same groups as those in R ¹ , and among them, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group are preferable.

  Specific examples of the acyl group include an acetyl group.

Specific examples of the aryl group include the same groups as those in R ¹ , and among them, a phenyl group is preferable.

  M in the general formula (1) represents an integer of 0 to 3. When m is 0, a tetrafunctional silane, when m is 1, a trifunctional silane, when m is 2, a bifunctional silane, and when m is 3, a monofunctional silane.

  Specific examples of the tetrafunctional silane include tetramethoxysilane, tetraethoxysilane, tetraacetoxysilane, and tetraphenoxysilane.

  Specific examples of the trifunctional silane include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltrin-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltrin -Butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, decyltrimethoxysilane Vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, phenol Rutrimethoxysilane, phenyltriethoxysilane, p-hydroxyphenyltrimethoxysilane, 1- (p-hydroxyphenyl) ethyltrimethoxysilane, 2- (p-hydroxyphenyl) ethyltrimethoxysilane, 4-hydroxy-5- ( p-hydroxyphenylcarbonyloxy) pentyltrimethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-amino Propyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4- Poxycyclohexyl) ethyltriethoxysilane, [(3-ethyl-3-oxetanyl) methoxy] propyltrimethoxysilane, [(3-ethyl-3-oxetanyl) methoxy] propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, Examples include 3-trimethoxysilylpropyl succinic acid.

  Specific examples of the bifunctional silane include dimethyldimethoxysilane, dimethyldiethoxylane, dimethyldiacetoxysilane, di-n-butyldimethoxysilane, diphenyldimethoxysilane, (3-glycidoxypropyl) methyldimethoxysilane, (3- And glycidoxypropyl) methyldiethoxysilane.

  Specific examples of the monofunctional silane include trimethylmethoxysilane, tri-n-butylethoxysilane, (3-glycidoxypropyl) dimethylmethoxysilane, (3-glycidoxypropyl) dimethylethoxysilane, and the like.

  These organosilanes may be used alone or in combination of two or more.

  Among these organosilanes, tetrafunctional silanes having m of 0 from the heat and heat resistance and hardness of the film are preferably used, and as the component (b), methyl silicate 51 (methyl silicate oligomer, average tetramer) methyl Silicate oligomers such as silicate 53 (methyl silicate oligomer, average heptamer), ethyl silicate 40 (ethyl silicate oligomer, average pentamer), and ethyl silicate 48 (ethyl silicate oligomer, average decamer) are particularly preferred.

When using silicate oligomer, the organoalkoxysilanes represented by the general formula (1), preferably more than 80 mol% of R ² is a hydrogen atom, more preferably more than 90 mol% is a hydrogen atom . Since there are many components that are previously hydroxyl groups, reactive silanol groups increase during siloxane curing, so that a cured film with a high crosslink density can be obtained, and thereby the moisture and heat resistance of the film obtained from the composition of the present invention can be increased. This is because the hardness is further improved.

The method for increasing the ratio of the hydroxyl group is not particularly limited, but there may be exemplified a method in which a silicate oligomer or a solution thereof is added with water of a chemical equivalent or more with respect to the OR ² group and heated to 40 ° C. or higher to be hydrolyzed. it can. At this time, it is also preferable to use a hydrolysis catalyst such as an acid or an alkali as necessary. Moreover, the method of hydrolyzing not only the state of (b) component single but the state of the composition of this invention can also be used preferably.

  The hydrolyzed condensate of organoalkoxysilane represented by the general formula (1) can be obtained by hydrolyzing an organosilane compound and then subjecting the hydrolyzed product to a condensation reaction in the presence of a solvent or without a solvent. .

  Various conditions for the hydrolysis reaction, for example, acid concentration, reaction temperature, reaction time, etc., can be appropriately set in consideration of the reaction scale, reaction vessel size, shape, etc. For example, in a solvent, an organosilane compound After adding an acid catalyst and water over 1 to 180 minutes, the reaction is preferably carried out at room temperature to 110 ° C. for 1 to 180 minutes. By performing the hydrolysis reaction under such conditions, a rapid reaction can be suppressed. The reaction temperature is more preferably 30 to 130 ° C.

  The hydrolysis reaction is preferably performed in the presence of an acid catalyst. Acid catalysts include hydrochloric acid, hydrobromic acid, hydroiodic acid and other halogenated inorganic acids, sulfuric acid, nitric acid, phosphoric acid, hexafluorophosphoric acid, hexafluoroantimonic acid, boric acid, tetrafluoroboric acid, Other inorganic acids such as chromic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid and other sulfonic acids, acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, Examples thereof include carboxylic acids such as tartaric acid, pyruvic acid, citric acid, succinic acid, fumaric acid and malic acid.

  From the viewpoint of storage stability of the composition, it is possible to remove part or all of the acid component by using an acid catalyst having a low boiling point and controlling the system beyond the boiling point of the acid catalyst after the hydrolysis reaction. preferable.

  The content of the acid catalyst is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the total organosilane compound used during the hydrolysis reaction. By controlling the amount of the acid catalyst within the above range, it can be easily controlled so that the hydrolysis reaction proceeds as necessary and sufficiently.

  After obtaining the silanol compound by the hydrolysis reaction of the organosilane compound, it is preferable to carry out the condensation reaction by heating the reaction solution as it is at 50 ° C. or higher and below the boiling point of the solvent for 1 to 100 hours. In order to increase the degree of polymerization of the polysiloxane, reheating or a base catalyst may be added.

  The solvent used for the hydrolysis reaction of the organosilane compound and the condensation reaction of the hydrolyzate is not particularly limited, and can be appropriately selected in consideration of the stability, wettability, volatility, etc. of the resin composition. In addition, two or more solvents may be combined, or the reaction may be performed without solvent. Specific examples of the solvent include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1-methoxy-2-propanol, pentanol, 4-methyl-2-pentanol, and 3-methyl-2- Alcohols such as butanol, 3-methyl-3-methoxy-1-butanol, 1-t-butoxy-2-propanol, diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol t-butyl ether, propylene glycol n- Cyl ether ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol monomethyl ether, diisopropyl ether, di n-butyl ether, diphenyl ether, diethylene glycol ethyl Ethers such as methyl ether, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether; methyl ethyl ketone, acetylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, 2-heptanone, diisobutyl ketone, cyclohexanone, Ketones such as loheptanone; Amides such as dimethylformamide and dimethylacetamide; Isopropyl acetate, ethyl acetate, propyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl acetoacetate, ethylene Glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl diglycol acetate, 1,3-butylene Glycol diacetate, ethyl diglycol acetate, dipropylene glycol methyl Acetates such as ether acetate, methyl lactate, ethyl lactate, butyl lactate, triacetyl glycerin; aromatics or fats such as toluene, xylene, hexane, cyclohexane, ethyl benzoate, naphthalene, 1,2,3,4-tetrahydronaphthalene Group hydrocarbons, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylimidazolidinone, dimethyl sulfoxide, propylene carbonate and the like.

(C) Silane compound represented by general formula (2) or (3) The composition of the present invention contains a silane compound represented by general formula (2) or (3). It is possible to obtain an antireflection film excellent in heat and moisture resistance.

  Regarding the moisture and heat resistance of the glass, which is a problem in the present invention, in general, when glass or glass coated with an antireflection layer is used under high temperature and high humidity conditions, a decrease in transmittance is observed due to deterioration. This mechanism is recognized as a glass burn.

Specifically, alkali metal ions such as sodium contained inside the substrate glass move to the surface by ion exchange with proton ions in water vapor under wet heat, and hydroxylate such as NaOH by reaction with water in the atmosphere. It becomes a thing. Since this is a strong alkali, the glass surface or the antireflection layer is dissolved, forming irregularities on the surface and forming a white cloud. Furthermore, alkali hydroxides such as NaOH react with water and carbon dioxide in the atmosphere to form crystalline substances such as Na ₂ CO ₃ and NaHCO ₃ . Further, dissolution of the glass with NaOH exposes other metal ions such as calcium ions, and reacts with carbon ions in the atmosphere to form crystals of other metal ions such as CaCO ₃ . These crystals become foreign substances and reduce the transmittance.

  Therefore, it can be said that the heat-and-moisture resistance is improved if the film thickness or transmittance of the antireflection layer is suppressed even under high temperature and high humidity conditions. The mechanism by which the heat and moisture resistance of the film is improved is estimated, but is considered as follows.

  The compound represented by the general formula (2) has an imide structure, which is considered to work as a material for improving adhesion to a glass substrate.

  In addition, the compound represented by the general formula (3) has an amic acid structure, which is dehydrated and closed in the course of curing after the composition is applied to a glass substrate, and is represented by the general formula (2). It seems to be a compound. Therefore, the function as an adhesion improving material is exhibited.

  Furthermore, the compound represented by the general formula (3) serves as a curing catalyst for curing the particles of the component (A) and / or the siloxane of the component (B) at the time of curing, so that an antireflection layer having a high crosslinking density is formed. It is thought that it becomes. Therefore, it is considered that the function of blocking water vapor is further enhanced.

  As described above, the anti-reflection layer has a high crosslink density and the adhesion between the anti-reflection layer and the glass substrate is strengthened, so that water vapor is blocked by the anti-reflection film and the arrival at the glass substrate is suppressed. It is estimated that the heat and humidity resistance is improved.

Here, regarding the curing of the composition, when the base material is heat strengthened glass, it is possible to heat strengthen the glass, apply the composition after cooling, and heat cure, but further improve durability such as heat and moisture resistance. From the viewpoint of making the composition, a process in which the glass substrate is thermally strengthened and cured after the composition is applied to the glass substrate is preferable. This is because the siloxane-based composition can be made into SiO ₂ by thermal decomposition of organic components, integrated with a semi-molten glass base material, and substrate adhesion can be improved.

  Since the heat strengthening process generally includes a step of heating the glass with hot air at a temperature of 500 ° C. or higher and 750 ° C. or lower for several tens of seconds, the organic components in the composition are thermally decomposed, and the additives have the expected functions. lose. However, those containing the silane compound represented by the general formula (2) or (3) maintain the effect because of the high heat resistance of the compound. Therefore, the heat and humidity resistance can be further increased.

The alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the phenyl group, and the phenoxy group in R ³ in the general formulas (2) and (3) may be either unsubstituted or substituted, It can be selected according to the characteristics of the composition.

Specific examples of the alkyl group having 1 to 6 carbon atoms include the same groups as those having 1 to 6 carbon atoms in R ¹ .

  Specific examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, cyclopropoxy group, butoxy group, isobutoxy group, t-butoxy group, pentyloxy group, hexyloxy group, Examples include a cyclohexyloxy group.

In the general formulas (2) and (3), R ⁴ is an acid anhydride residue. The acid anhydride constituting R ⁴ preferably contains an aromatic ring or an aliphatic ring. Specific examples of such acid anhydrides include maleic anhydride, phthalic anhydride, methyl phthalic anhydride, succinic anhydride, glutaric anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, cis- 4-cyclohexene-1,2-dicarboxylic acid anhydride, cis-1,2-cyclohexanedicarboxylic acid anhydride, 1,8-naphthalic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid anhydride, 5 -Norbornene-2,3-dicarboxylic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, "Ricacid (registered trademark)" HNA (trade name, manufactured by Shin Nippon Rika Co., Ltd.), "Ricacid “HNA-100 (trade name, manufactured by Shin Nippon Rika Co., Ltd.) and those obtained by substituting some hydrogen atoms of these acid anhydrides with monovalent organic groups having 1 to 10 carbon atoms can be mentioned. . Examples of the monovalent organic group having 1 to 10 carbon atoms include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group, an oxymethyl group, an oxyethyl group, and an oxy n-propyl group. And oxyalkyl groups such as oxy n-butyl group and oxy n-pentyl group. Of these, a methyl group, an ethyl group, an n-propyl group, and an n-butyl group are preferable because they can be easily produced. Among the acid anhydrides, phthalic anhydride, succinic anhydride, glutaric anhydride, 4-methylcyclohexane-1,2-dicarboxylic anhydride, 1,8-naphthalic anhydride, 5-norbornene-2,3 -Dicarboxylic acid anhydride, methyl phthalic anhydride, and those substituted with a monovalent organic group having 1 to 10 carbon atoms are preferred. Of these, phthalic anhydride, succinic anhydride, and glutaric anhydride are more preferable from the viewpoints of transparency and adhesiveness.

R ¹ in the general formulas (2) and (3) is a monovalent monovalent group having 1 to 20 carbon atoms composed of any number of atoms selected from carbon atoms not containing silicon atoms, hydrogen atoms, oxygen atoms, and nitrogen atoms. Specific examples of the group include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, pentyl group, hexyl group, cyclohexyl group, heptyl group, octyl group, and the like. Examples thereof include hydroxyalkyl groups such as a hydroxyethyl group, aryl groups such as a phenyl group, hydroxyaryl groups such as methoxyphenyl, alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group. Among these, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, and a pentyl group are more preferable from the viewpoint of adhesiveness. Since R ⁵ does not contain a silicon atom, it is not colored and is suitable for an antireflection layer that requires transparency.

  Examples of the silane compound represented by the general formula (2) include 1- (tert-butyl) -3- (3- (trimethoxysilyl) propyl) pyrrolidine-2,5-dione, 1-isopropyl-3- (3- (trimethoxysilyl) propyl) pyrrolidine-2,5-dione, 1-isobutyl-3- (3- (trimethoxysilyl) propyl) pyrrolidine-2,5-dione, 1- (tert-pentyl)- 3- (3- (trimethoxysilyl) propyl) pyrrolidine-2,5-dione, 1- (tert-butyl) -3- (3- (dimethoxy (methyl) silyl) propyl) pyrrolidine-2,5-dione, Examples include 1- (tert-butyl) -3- (3- (trimethoxysilyl) ethyl) pyrrolidine-2,5-dione.

  Examples of the silane compound represented by the general formula (3) include 3- (tert-butylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid, 2- (2- (tert-butylamino) -2- Oxoethyl) -5- (trimethoxysilyl) pentanoic acid, 3- (isopropylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid, 2- (2- (isopropylamino) -2-oxoethyl) -5- (tri Methoxysilyl) pentanoic acid, 3- (isobutylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid, 2- (2- (isobutylamino) -2-oxoethyl) -5- (trimethoxysilyl) pentanoic acid, 3 -(Tert-pentylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid, 2- (2- (tert-pentylamino)- -Oxoethyl) -5- (trimethoxysilyl) pentanoic acid, 3- (tert-butylcarbamoyl) -6- (triethoxysilyl) hexanoic acid, 2- (2- (tert-butylamino) -2-oxoethyl) -5- (triethoxysilyl) pentanoic acid, 6- (dimethoxy (methyl) silyl) -3- (tert-butylcarbamoyl) hexanoic acid, 5- (dimethoxy (methyl) silyl-2- (2- (tert- Butylamino) -2-oxoethyl) pentanoic acid, 3- (tert-butylcarbamoyl) -6- (trimethoxysilyl) pentanoic acid, 2- (2- (tert-butylamino) -2-oxoethyl) -5- ( Trimethoxysilyl) butanoic acid, 2- (tert-butylcarbamoyl) -4- (2- (trimethoxysilyl) ethyl) si B hexane carboxylic acid, such as 2- (tert-butylcarbamoyl) -5- (2- (trimethoxysilyl) ethyl) cyclohexanecarboxylic acid.

  These silane compounds may be used alone or in combination.

  As a method for producing these silane compounds, a method of producing by reacting an acid anhydride-containing silane coupling agent with an alkylamine is preferable from the viewpoint of ease of production. In this case, depending on the structure of the silane coupling agent containing an acid anhydride, when two types of silane compounds represented by the general formula (3) are obtained, the silane compounds represented by the general formula (2) and the general It may be obtained as a mixture of silane compounds represented by formula (3). Here, when the reaction temperature is increased or the reaction time is increased and the ring-closing condensation of the silane compound represented by the general formula (2) is promoted, the silane compound represented by the general formula (3) is obtained. However, in the object of the present invention, these can be used as a mixture without being separated and purified. In addition, although a small amount of oligomer or the like can be replicated in this synthesis method, it does not significantly affect the adhesion improvement effect and need not be considered.

  The content is preferably 0.5 parts by weight or more and 15 parts by weight or less, more preferably 100 parts by weight, based on the total amount of the hydrolyzed condensate of the component (a) chain silica particles and the component (b) organoalkoxysilane. 1 part by weight or more and 10 parts by weight or less. By being in this range, both high transparency and adhesion to the substrate can be achieved.

(D) Solvent The solvent is not particularly limited and can be appropriately selected in consideration of the stability, wettability, volatility, etc. of the coating composition. Two or more solvents may be combined. Specific examples of the solvent include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, 1-methoxy-2-propanol, pentanol, 4-methyl-2-pentanol, and 3-methyl-2- Alcohols such as butanol, 3-methyl-3-methoxy-1-butanol, 1-t-butoxy-2-propanol, diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monomethyl ether, ethylene glycol mono Ethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol t-butyl ether, propylene glycol n- Cyl ether ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol-n-butyl ether, dipropylene glycol monomethyl ether, diisopropyl ether, di n-butyl ether, diphenyl ether, diethylene glycol ethyl Ethers such as methyl ether, diethylene glycol dimethyl ether, ethylene glycol monobutyl ether; methyl ethyl ketone, acetylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclopentanone, 2-heptanone, diisobutyl ketone, cyclohexanone, Ketones such as loheptanone; Amides such as dimethylformamide and dimethylacetamide; Isopropyl acetate, ethyl acetate, propyl acetate, butyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl acetoacetate, ethylene Glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, butyl diglycol acetate, 1,3-butylene Glycol diacetate, ethyl diglycol acetate, dipropylene glycol methyl Acetates such as ether acetate, methyl lactate, ethyl lactate, butyl lactate, triacetyl glycerin; aromatics or fats such as toluene, xylene, hexane, cyclohexane, ethyl benzoate, naphthalene, 1,2,3,4-tetrahydronaphthalene Group hydrocarbons, γ-butyrolactone, N-methyl-2-pyrrolidone, N, N-dimethylimidazolidinone, dimethyl sulfoxide, propylene carbonate and the like.

  The selection of the solvent also takes into account the evaporation rate, the coating material having good wettability between the coating material and the substrate to which the coating material is applied, and the viewpoint of preventing aggregation and precipitation of solutes in the coating material. For example, when evaporating faster or lowering the drying temperature, it is preferable to increase the low-boiling point solvent alone or the blend ratio. When the drying temperature is increased or the liquid is used in an open system, the liquid agglomerates. In order to suppress this, it is preferable to increase the high boiling point solvent alone or the blend ratio.

  In addition to the organic solvent, it is also preferable to use water alone or in a blend system. As a preferable solvent used in the present invention, a hydrophilic alcohol solvent having good dispersion stability of fine particles is preferable, and specifically, methanol, ethanol and isopropyl alcohol are preferable. Also, propylene glycol monoethyl ether or water is preferable from the viewpoints of coatability with the substrate and surface uniformity of the coating film after drying. These blend systems are also preferred.

(Other ingredients)
The composition of the present invention may contain a metal chelate compound. As a metal chelate compound, if it has a metal and a multidentate ligand, it will not specifically limit, Furthermore, the metal may have an organic group.

  Examples of the metal in the metal chelate compound include aluminum, titanium, zirconium, copper, chromium, cobalt and the like. Examples of the multidentate ligand include acetylacetonato ion and ethyl acetoacetate. Examples of the organic group include alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a sec-butoxy group, and a tert-butoxy group.

  Specific examples of the metal chelate compound include trimethoxy mono (acetylacetonato) aluminum, triethoxy mono (acetylacetonato) aluminum, tri-n-propoxy mono (acetylacetonato) aluminum, tri- iso-propoxy mono (acetylacetonato) aluminum, tri-n-butoxy mono (acetylacetonato) aluminum, tri-sec-butoxy mono (acetylacetonato) aluminum, tri-tert-butoxy mono (acetylacetate) Nato) aluminum, dimethoxy-di (acetylacetonato) aluminum, diethoxy-di (acetylacetonato) aluminum, di-n-propoxy-di (acetylacetonato) aluminum, diiso-propoxy Di (acetylacetonato) aluminum, di-n-butoxy-di (acetylacetonato) aluminum, disec-butoxy-di (acetylacetonato) aluminum, di-tert-butoxy-di (acetylacetonato) aluminum, monomethoxy- Tris (acetylacetonato) aluminum, monoethoxy-tris (acetylacetonato) aluminum, mono-n-propoxy-tris (acetylacetonato) aluminum, monoiso-propoxy-tris (acetylacetonato) aluminum, mono-n-butoxy Tris (acetylacetonato) aluminum, mono-sec-butoxy-tris (acetylacetonato) aluminum, mono-tert-butoxy-tris (acetylacetonato) aluminum, tetrakis (acetylacetate) Nato) aluminum, trimethoxy mono (ethyl acetoacetate) aluminum, triethoxy mono (ethyl acetoacetate) aluminum, tri-n-propoxy mono (ethyl acetoacetate) aluminum, tri-iso-propoxy mono (ethyl acetoacetate) Aluminum, tri-n-butoxy mono (ethyl acetoacetate) aluminum, tri-sec-butoxy mono (ethyl acetoacetate) aluminum, tri-tert-butoxy mono (ethyl acetoacetate) aluminum, dimethoxy di (ethyl acetoacetate) Acetate) titanium, diethoxy di (ethyl acetoacetate) aluminum, di-n-propoxy di (ethyl acetoacetate) aluminum, diiso-propoxy di (eth) Ruacetoacetate) aluminum, di-n-butoxy-di (ethylacetoacetate) aluminum, disec-butoxy-di (ethylacetoacetate) aluminum, ditert-butoxy-di (ethylacetoacetate) aluminum, monomethoxy-tris ( Ethyl acetoacetate) aluminum, monoethoxy tris (ethyl acetoacetate) aluminum, mono n-propoxy tris (ethyl acetoacetate) aluminum, monoiso-propoxy tris (ethyl acetoacetate) aluminum, mono n-butoxy tris ( Ethyl acetoacetate) aluminum, mono sec-butoxy tris (ethyl acetoacetate) aluminum, mono tert-butoxy tris (ethyl acetoacetate) al Chloride, tetrakis (ethylacetoacetate) aluminum and the like. In the case of a metal chelate compound of other metal types such as titanium, zirconium, copper, chromium, cobalt, etc., it is preferable to use a chelate compound having the above-mentioned ligand and organic group in the above-mentioned aluminum chelate compound according to the coordination number of the metal. it can. These may be used individually by 1 type and may be used in combination of 2 or more types.

  These improve the durability and hardness of the film obtained from the composition by a siloxane curing catalyst and a crosslinking effect by metal. In particular, among the metal species of the metal chelate compound, aluminum and titanium are particularly effective in improving the heat and moisture resistance, and when used in combination with the silane compound represented by the general formula (2) or (3) described above, the heat and moisture resistance is synergistically achieved. Will improve.

  Although the mechanism of improving the heat and humidity resistance by the metal chelate compound is presumed, it is considered that the water vapor barrier property is improved by the action of the siloxane as a curing catalyst and the metal crosslinking effect after the formation of the antireflection layer. Accordingly, the metal chelate-containing product can suppress dissolution of the glass substrate or the antireflection layer under high temperature and high humidity conditions. Moreover, the fall of the transmittance | permeability on high temperature, high humidity conditions can also be suppressed by use of specific metal seed | species in a metal chelate compound. In particular, when an aluminum or titanium-based metal chelate compound is used, no decrease in transmittance is observed, and the addition of the metal chelate compound improves the moisture and heat resistance in terms of transmittance in addition to maintaining the film thickness. That is, in the wet heat test of the glass coated with the antireflection layer, the change in transmittance before and after the test becomes small.

  The preferred content of the metal chelate is 0.5 parts by weight or more and 15 parts by weight or less based on 100 parts by weight of the total amount of the chain silica particles of the component (a) and the hydrolyzed condensate of the organoalkoxysilane of the component (b). Preferably they are 1 weight part or more and 10 weight part or less. By being in this range, both high transparency and heat-and-moisture resistance can be achieved.

  The composition of the present invention may contain an acid component. Examples of the acid component include organic acids and inorganic acids.

  Examples of organic acids include formic acid, maleic acid, fumaric acid, phthalic acid, malonic acid, succinic acid, tartaric acid, malic acid, lactic acid, citric acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid Organic acids such as octanoic acid, nonanoic acid, decanoic acid, oxalic acid, adipic acid, sebacic acid, butyric acid, oleic acid, stearic acid, linoleic acid, linolenic acid, salicylic acid, benzoic acid, p-aminobenzoic acid, Examples thereof include organic sulfonic acid compounds such as benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, and trifluoroethanesulfonic acid.

  Examples of inorganic acids include hydrochloric acid, phosphoric acid, nitric acid, boric acid, sulfuric acid, and hydrofluoric acid.

  Of these, organic carboxylic acids are preferably used because they do not form foreign matters and are thermally decomposed during thermosetting, and formic acid, acetic acid, oxalic acid, and succinic acid are particularly preferred. These acid components may be used alone or in combination of two or more.

  A preferable content of the acid component is 0.001 wt% or more and 1 wt% or less with respect to the entire composition. By being in this range, the curing of the composition and the transparency of the coating film can be made compatible at a higher level.

  Since the acid component is a siloxane curing catalyst, curing of the composition after application to the substrate can be accelerated. For example, in a cover glass for a solar cell, a glass whose surface is embossed to prevent glare is common. When the composition is applied to the surface of such glass, the liquid flows into the concave portion from the convex portion of the embossed concave / convex portion, resulting in a non-uniform film thickness of the coating layer. It will be small. Accordingly, by speeding up the curing after application with the acid component, the inflow of the liquid is suppressed, and a relatively conformal coating layer is formed on the embossed irregularities. For this reason, a large transmittance improvement effect can be obtained even on the concavo-convex substrate.

  FIG. 2A is a schematic explanatory view of an embossed substrate. Generally, the emboss height H is 5 to 15 nm and the emboss period W is 500 to 2000 nm, although it varies depending on the glass.

  FIG. 2B is an explanatory diagram of a state in which a film is applied to the embossed substrate. If the liquid flows into the recesses before drying, the thickness of the coating film 1 becomes uneven.

  The composition of the present invention may contain a silane coupling agent other than the silane compounds represented by the general formulas (2) and (3).

  Specific examples of the silane coupling agent include dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-methacrylate. Loxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-glycidoxypropyltri Toxisilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltri Ethoxysilane, [(3-ethyl-3-oxetanyl) methoxy] propyltrimethoxysilane, [(3-ethyl-3-oxetanyl) methoxy] propyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyl Examples include dimethoxysilane, 3-ureidopropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, and 3-trimethoxysilylpropyl succinic acid.

  Although there is no restriction | limiting in particular in content of a silane coupling agent, When using, Preferably it is the range of 0.1-15 weight part with respect to 100 weight part of particle | grains / siloxane total amount. By being in this range, it is preferable because both storage stability and adhesion of the coating film to the substrate can be achieved.

  The composition of the present invention may contain a surfactant. By containing the surfactant, coating unevenness is improved and a uniform coating film is obtained. Fluorine surfactants and silicone surfactants are preferably used.

  Specific examples of the fluorosurfactant include 1,1,2,2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl) ether, 1,1,2,2-tetrafluorooctyl. Hexyl ether, octaethylene glycol di (1,1,2,2-tetrafluorobutyl) ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl) ether, octapropylene glycol di (1 , 1,2,2-tetrafluorobutyl) ether, hexapropylene glycol di (1,1,2,2,3,3-hexafluoropentyl) ether, sodium perfluorododecylsulfonate, 1,1,2,2 , 8,8,9,9,10,10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, N- [3- (Perful Looctanesulfonamido) propyl] -N, N′-dimethyl-N-carboxymethyleneammonium betaine, perfluoroalkylsulfonamidopropyltrimethylammonium salt, perfluoroalkyl-N-ethylsulfonylglycine salt, bis (N-par) phosphate Fluorosurfactant comprising a compound having a fluoroalkyl or fluoroalkylene group in at least one of the terminal, main chain and side chain, such as fluorooctylsulfonyl-N-ethylaminoethyl) and monoperfluoroalkylethyl phosphate ester An agent can be mentioned. Commercially available products include MegaFuck F142D, F172, F173, F183, F183, F444, F475, F477 (above, manufactured by Dainippon Ink & Chemicals, Inc.), Ftop EF301, 303, 352 (made by Shin-Akita Kasei Co., Ltd.), Florard FC-430, FC-431 (made by Sumitomo 3M)), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (Asahi Glass Co., Ltd.), BM-1000, BM-1100 (Yusho Co., Ltd.), NBX-15, FTX-218, There are fluorine-based surfactants such as DFX-218 (manufactured by Neos).

  Commercially available silicone surfactants include SH28PA, SH7PA, SH21PA, SH30PA, ST94PA (all manufactured by Toray Dow Corning Silicone), BYK067A, BYK310, BYK322, BYK331, BYK333, BYK355 (BIC Chemie Japan) Etc.).

  The content of the surfactant is generally 0.0001 to 1% by weight in the composition.

  In addition, the composition of the present invention may contain various additives such as a crosslinking agent, a thermal radical generator, a surfactant, a thickener, a stabilizer, an antifoaming agent, and metal compound particles other than silica particles. Good.

  Although there is no restriction | limiting in particular as solid content concentration, the composition of this invention is 0.3 to 30 weight% in a preferable range. This range is preferable because both good storage stability and film thickness controllability during coating can be achieved.

  Next, a method for forming an antireflection layer on the glass surface using the composition of the present invention will be described in detail. The method for forming an antireflection layer using the composition of the present invention includes a step of applying the composition of the present invention to a glass surface and heating and curing the composition.

  As a coating method, glass is formed by a known coating method such as a slit coating method, a spin coating method, a roll coating method, a spray coating method, a relief printing method, an intaglio printing method, a screen printing method, an ink jet printing method, a slit printing method, or a dip coating method. It can be applied to a substrate. Of these, the slit coat method, roll coat method, spray coat method, and dip coat method are particularly preferred in view of coating accuracy and maintainability.

  The coating film thickness is preferably controlled to about ¼ of the wavelength at which the maximum antireflection function is desired from the Fresnel equation. For example, in the cover glass of a solar cell, it is preferable to apply with a film thickness of 90 nm or more and 200 nm or less.

  It is also preferable to dry the solvent at room temperature after coating, and it is also preferable to dry the solvent by heating. In the case of applying to an uneven substrate, it is preferable to accelerate drying by heating because the flow of liquid can be suppressed. The drying conditions are not particularly limited, but are preferably 50 ° C. or higher and 350 ° C. or higher, and more preferably 50 ° C. or higher and 150 ° C. or lower from the viewpoint of productivity.

  Subsequently, the composition of the present invention is cured. At this time, it is preferable from the viewpoint of film durability and process cost that the composition is cured together with the heat strengthening of the glass. That is, it is preferable that the heat strengthening process is a coating film curing process and also a process for strengthening the glass.

  The heating temperature is preferably about 500 to 750 ° C, more preferably about 600 to 720 ° C. When the heating temperature is within this range, it is more preferable because both the strength of the heat strengthened glass and the durability of the antireflection film can be achieved.

  The laminated body after the heat treatment is taken out from the heating furnace and immediately cooled by blowing air onto its surface.

  Next, the case where the antireflection film of this embodiment is applied to a solar cell module will be described with reference to the drawings. FIG. 3 is a schematic cross-sectional view of a solar cell module including a laminate obtained by forming the antireflection film according to the present embodiment on a white plate tempered glass.

  A solar cell module 10 shown in FIG. 3 includes a white plate tempered glass 3 as a cover glass and an antireflection film 2 formed on the surface thereof. This glass laminate is produced using the above-described method for forming an antireflection film. The back surface 6 of the solar cell module 10 is provided with a back sheet 6 having excellent water resistance. As the back sheet 6, a film having a laminated structure in which a metal foil such as an Al film is usually sandwiched between PVF (polyvinyl fluoride) resins is preferably used. A gap between the solar battery cell 4 and the white plate tempered glass 3 or the back sheet 6 is filled with a sealing material 5. For the sealing material 5, for example, a thermosetting resin having a high light transmittance such as EVA (ethylene vinyl acetate) is used. The sealing material 5 has a function of adhering the white plate tempered glass 3, the solar battery cell 4, and the back sheet 6 to each other simultaneously with the filling of the gap. By having the antireflection film 2 on the white plate tempered glass 3, the amount of light taken in from the surface side of the solar cell module 10 is increased, and a solar cell module excellent in power generation efficiency can be obtained.

  In addition, the composition of this invention can be used also for the glass for building materials, the glass for motor vehicles, and the glass for displays besides the cover glass for solar cells.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to these Examples. In addition, it shows below about what used the abbreviation among the used compounds.

DAA: diacetone alcohol (bp 169 ° C.)
IPA: isopropyl alcohol (bp 82 ° C)
PGME: 1-methoxy-2-propanol (bp 118 ° C.)
M-51: Methyl silicate 51 (methyl silicate oligomer, average tetramer)
MeTMS: methyltrimethoxysilane PhTMS: phenyltrimethoxysilane SuccTMS: 3- (trimethoxysilylpropyl) succinic anhydride AcrylTMS: 3-acryloxypropyltrimethoxysilane AL-A: aluminum trisacetylacetonate Ti-A: titanium Tetraacetylacetonate Zc-A zirconium tris (acetylacetonate) ethylacetoacetate OX-SC: oxetanyl silicate.

(1) Average primary particle diameter of silica particles The average primary particle diameter (D) of silica particles is obtained by spin-coating a dispersion of silica particles on a silicon substrate and observing with an electron microscope. And the minor axis were measured, and the average value thereof was D. The results are summarized in Table 1.

  Measurements were performed on Snowtex OUP (water sol), IPA-ST-UP (IPA sol), Snowtex ST-PS-MO (water sol), and Snowtex ST-O (water sol) manufactured by Nissan Chemical Co., Ltd. SNOWTEX OUP, IPA-ST-UP, and SNOWTEX ST-PS-MO were chain silica.

(2) Solid content concentration 1 g of the solution to be measured was weighed in an aluminum cup and heated at 250 ° C. for 30 minutes using a hot plate to evaporate the liquid content. The solid content remaining in the heated aluminum cup was weighed to determine the solid content concentration of the solution.

(3) Measurement of light transmittance Measurement was performed using an integrating sphere spectrophotometer system U-4100 manufactured by Hitachi High-Technologies Corporation. In addition, it computed as the average value of the transmittance | permeability T in wavelength 400-700nm.

(4) Measurement of refractive index The composition was applied on a silicon wafer so as to have a thickness of 1.5 to 4 μm using a spin coater, then heated and dried in an oven at 150 ° C. for 10 minutes, and 700 The coating film was obtained by baking at 1 ° C. for 1 h. The refractive index at a wavelength of 633 nm of the coating film was measured with a prism coupler (manufactured by METRICON: MODEL 2010).

(5) Measurement of hydrolysis ratio The water content in the solution was quantified with a Karl Fischer water content titration apparatus, the amount of water consumed by hydrolysis was determined from the difference from the water content added in advance, and the hydrolysis ratio was calculated.

(6) Initial characteristic evaluation The composition was slit-coated on one side so as to have a dry film thickness of 130 nm on a flat plate white glass having a thickness of 350 mm × 350 mm and a thickness of 3.2 mm. This was pre-baked at 150 ° C. for 5 minutes, and heat strengthened at 680 ° C. The transmittance (T-coated product) of this glass is measured, and compared with the transmittance (T-uncoated product) before applying the composition, the flat plate transmittance improvement value (T-coated product-T-uncoated product) Calculated as Moreover, the pencil hardness was measured. The pencil hardness was measured according to JIS K-5600-5-4 (1999) using a manual pencil scratch hardness tester (No. 850-56 manufactured by Coating Tester Co., Ltd.).

  Moreover, the base material was changed from flat white plate glass to embossed white plate glass, the same operation was performed, and it measured as an embossing transmittance | permeability raise value.

(7) Moisture and heat resistance evaluation The composition was slit-applied on one side of 100 mm × 50 mm and 0.8 mm thick blue plate glass to a dry film thickness of 130 nm, and prebaked at 150 ° C. for 5 minutes. Thereafter, the composition was slit-coated on the opposite surface so as to have the same dry film thickness, and prebaked at 150 ° C. for 5 minutes. The glass was heat-treated at 600 ° C. for 1 hour to produce a glass having antireflection films formed on both sides. This glass was allowed to stand for 240 hours under the processing conditions of 121 ° C., 2.1 atm, and 100% RH. The film thickness of the antireflection film before and after the treatment was measured with a stylus film thickness meter, and the film thickness retention rate was calculated. Moreover, the transmittance | permeability of the glass before and after a process was measured, respectively, and the transmittance | permeability change before and after a process was computed. Here, those having small changes in film thickness and transmittance before and after the treatment have good heat and humidity resistance.

  Regarding the film thickness, a part of the cured film on both sides was cut off for each measurement before and after the treatment, and a stylus type surface roughness and shape measuring machine Surfcom 1400D (trade name, manufactured by Tokyo Seimitsu Co., Ltd.) The measurement was performed using an average value of the film thickness on both sides.

Synthesis Example 1 Synthesis of Silane Coupling Agent Mixed Solution (A-1) To 200 g of PGMEA, 41.97 g (160 mmol) of 3-trimethoxysilylpropyl succinic anhydride and 11.70 g (160 mmol) of t-butylamine were added and kept at room temperature for a while. And stirred at 40 ° C. for 2 hours. Then, it heated up to 80 degreeC and made it react for 6 hours. The resulting solution was diluted with PGMEA so that the solid concentration was 20%, and 3- (tert-butylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid, 2- (2- (tert-butylamino) was obtained. ) -2-Oxoethyl) -5- (trimethoxysilyl) pentanoic acid mixed solution (A-1, corresponding to general formula (3)) was obtained.

Synthesis Example 2 Synthesis of Silane Coupling Agent Mixed Solution (A-2) To 400 g of PGME, 41.97 g (160 mmol) of 3-trimethoxysilylpropyl succinic anhydride and 11.70 g (160 mmol) of t-butylamine were added at room temperature. After stirring for 30 minutes, the mixture was stirred at 60 ° C. for 2 hours. Then, it heated up to 140 degreeC and made it react for 6 hours, making PGME and water azeotrope. The obtained solution was diluted with PGME so that the solid content concentration was 20% by weight, and 1- (tert-butyl) -3- (3- (trimethoxysilyl) propyl) pyrrolidine-2, which is an imidosilane compound, A solution of 5-dione (A-2, corresponding to general formula (2)) was obtained.

Synthesis Example 3 Synthesis of Silane Coupling Agent Mixed Solution (B-1) To 200 g of PGMEA, 41.97 g (160 mmol) of 3-trimethoxysilylpropyl succinic anhydride and 9.45 g (160 mmol) of t-pentylamine were added for a while at room temperature. And then stirred at 40 ° C. for 2 hours. Then, it heated up to 80 degreeC and made it react for 6 hours. The resulting solution was diluted with PGMEA so that the solid concentration was 20%, and 2- (2- (t-pentylamino) -2-oxoethyl) -5- (trimethoxysilyl) pentanoic acid, 3- ( A mixed solution of tert-pentylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid (B-1, corresponding to the general formula (3)) was obtained.

Synthesis Example 4 Synthesis of Silane Coupling Agent Mixed Solution (C-1) To 200 g of PGMEA was added 41.97 g (160 mmol) of 3-trimethoxysilylpropyl succinic anhydride and 9.45 g (160 mmol) of isopropylamine at room temperature for a while. After stirring, the mixture was stirred at 40 ° C. for 2 hours. Then, it heated up to 80 degreeC and made it react for 6 hours. The resulting solution was diluted with PGMEA so that the solid concentration was 20%, and 2- (2- (isopropylamino) -2-oxoethyl) -5- (trimethoxysilyl) pentanoic acid, 3- (tert- A mixed solution of isopropylcarbamoyl) -6- (trimethoxysilyl) hexanoic acid (C-1, corresponding to the general formula (3)) was obtained.

Example of Siloxane Polymerization In a 500 mL three-necked flask, 55.07 g of KBM-13 (methyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.), 45.82 g of KBM-103 (phenyltrimethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.), X-12-967C ( 30.30 g of Shin-Etsu Chemical Co., Ltd. (trimethoxysilylpropyl succinic anhydride), KBM5103 (3-Ethyloxypropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd.) 94.77 g, DAA (Diacetone Alcohol) 338.94 g, and nitrogen While stirring at 40 ° C. in an atmosphere, a phosphoric acid aqueous solution in which 0.45 g of phosphoric acid was dissolved in 64.46 g of water was added over 30 minutes. After completion of dropping, the mixture was stirred at 40 ° C. for 1 hour, then heated to 70 ° C. and stirred for 30 minutes. Thereafter, the temperature of the oil bath was raised to 115 ° C. After the start of temperature increase, the internal temperature of the solution reached 100 ° C. and heated from there for 1 hour. (Internal temperature is 100 to 110 ° C.) The obtained solution was cooled in an ice bath to obtain a polysiloxane solution S-1. The solid content concentration of the polysiloxane solution was 35%.

Hydrolysis of siloxane M-51 (methyl silicate oligomer, average polymerization degree 4) was added with water and heated at 70 ° C. for 1 hour to obtain a hydrolyzate S-2. As a result of calculating the water consumption after cooling in an ice bath, the hydrolysis ratio was 85%.

Examples 1-13
Each composition was prepared with the composition described in Tables 2-3, and refractive index measurement, initial characteristic evaluation, and wet heat resistance evaluation were performed by the above methods. As shown in Table 4, the transmittance improvement value was good, the film thickness retention in the moisture and heat resistance test was high, the change in transmittance was small, and good moisture and heat resistance was exhibited. In addition, when the composition contained an aluminum chelate or a titanium chelate, the heat and humidity resistance was synergistically improved. The hydrolyzed product of methyl silicate also had particularly high heat and humidity resistance.

Comparative Example 1
Compositions were prepared with the compositions shown in Tables 2 to 3, and refractive index measurement, initial characteristic evaluation, and wet heat resistance evaluation were performed by the above methods. Since the content of the chain silica particles was as low as less than 50 wt% in the total solid content, as shown in Table 4, the refractive index was high, and the transmittance improvement effect was small.

Comparative Examples 2-6
Compositions were prepared with the compositions shown in Tables 2 to 3, and refractive index measurement, initial characteristic evaluation, and wet heat resistance evaluation were performed by the above methods. When the silane compound represented by the general formula (2) or (3) was not used and another silane compound was used or nothing was used, as shown in Table 4, the moisture and heat resistance was greatly lowered.

Comparative Examples 7-8
Compositions were prepared with the compositions shown in Tables 2 to 3, and refractive index measurement, initial characteristic evaluation, and wet heat resistance evaluation were performed by the above methods. When the additive particles were changed to spherical particles other than the chain silica particles, as shown in Table 4, the refractive index could not be controlled low, and the transmittance improving effect was small.

D Primary particle diameter H Emboss height W Emboss period width 1 Coating film 2 Antireflection film 3 White plate tempered glass 4 Solar cell 5 Sealing material 6 Back sheet 10 Solar cell module

Claims (10)

(A) chain silica particles having an average primary particle diameter of 5 to 40 nm;
(B) a hydrolytic condensate of an organoalkoxysilane represented by the general formula (1);
(R ¹ ) _m Si (OR ² ) _4-m (1)
(In the formula, R ¹ represents hydrogen, an alkyl group, an alkenyl group, an aryl group, or a substituted product thereof. R ² may be the same or different, and represents an alkyl group, an acyl group, an aryl group, or a substituted product thereof. m represents an integer of 0 to 3.)
(C) a silane compound represented by the general formula (2) or (3);

(In the general formulas (2) and (3), R ³ may be the same or different and is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group, a phenoxy group, or a substituted product thereof. R ⁴ may be the same or different and represents a trivalent hydrocarbon group having 3 to 30 carbon atoms composed of a plurality of atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, and a nitrogen atom. R ⁵ may be the same or different and is a hydrogen atom or a C 1-20 having one or more atoms selected from a carbon atom not containing a silicon atom, a hydrogen atom, an oxygen atom, or a nitrogen atom. Represents a valent hydrocarbon group, and n represents an integer of 1 to 3.)
(D) a solvent;
And (a) a chain silica particle having an average primary particle diameter of 5 to 40 nm is contained in a total solid content of 50 wt% or more. (B) The composition according to claim 1, wherein m is 0 in the organoalkoxysilane represented by the general formula (1). Furthermore, the composition of Claim 1 or 2 containing a metal chelate compound. The composition according to claim 4, wherein the metal chelate compound is an aluminum chelate compound or a titanium chelate compound. Furthermore, the composition of any one of Claims 1-4 containing organic carboxylic acid. In organoalkoxysilane represented by (b) Formula (1), m is 0, any one composition according to claims 1 to 5 or 80 mol% of R ² is a hydrogen atom. The formation method of an antireflection layer including the process of apply | coating the composition of any one of Claims 1-6 on the glass surface, and heat-hardening glass by heating and hardening a composition after that. The antireflection layer formed by hardening | curing the composition of any one of Claims 1-6. A glass having the antireflection layer according to claim 8. The glass of Claim 9 is a cover glass for solar cells, The solar cell module containing this cover glass.

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