WO2013042278A1

WO2013042278A1 - Coating composition and coated article

Info

Publication number: WO2013042278A1
Application number: PCT/JP2011/076875
Authority: WO
Inventors: 福崎　僚三; 和彦金内; 田丸　博
Original assignee: パナソニック株式会社
Priority date: 2011-09-21
Filing date: 2011-11-22
Publication date: 2013-03-28
Also published as: TW201313845A

Abstract

The present invention provides a coating composition which has high weather resistance and alkali resistance, is capable of forming a coating with sufficiently high transparency and is especially suitable for forming an antireflection layer. This coating composition contains a curable resin and silica-based metal oxide particles. The curable resin comprises at least either one of a hydrolytically condensable compound or a partial hydrolysate thereof. A molecule of the hydrolytically condensable compound has an organic chain and a hydrolyzable silyl group bonded to each end of the organic chain. The organic chain comprises one or more groups selected from an optionally substituted alkylene group, an optionally substituted fluoroalkylene group and an ether group, and the organic chain has at least either one of the alkylene group or the fluoroalkylene group.

Description

Coating composition and painted product

The present invention relates to a coating composition used for forming an antireflection layer and the like, and a coated product provided with a film formed from a cured product of this coating composition.

In recent years, there has been a demand for measures for reducing the light reflectivity of a transparent base material installed on the outermost surface of advertising display devices such as digital signage and solar cells, which are attracting attention. When the reflectance of light on the transparent base material is reduced, for example, in an advertising display device, there is an advantage that image visibility is improved, and in a solar cell, the amount of light taken into the solar cell is increased. There is an advantage that power generation efficiency is improved. Thus, in order to reduce the reflectance of light on the surface of the transparent base material, conventionally, an antireflection layer has been provided on the surface of the base material.

As an example of a conventional coating composition for forming an antireflection layer, one containing a hydrolyzable organosilane or a partially hydrolyzed condensate thereof can be mentioned. For example, the coating composition described in Patent Document 1 includes the following (A) hydrolyzable organosilane, the following (B) hydrolyzable organosilane and silica-based metal oxide particles in a mixed state. (A) and a hydrolyzable organosilane of the following (B), a hydrolyzable organosilane of the following (C) and a hydrolyzable organosilane of the following (C): And a polymerized second hydrolyzate having a fluorine-substituted alkyl group at one end.
(A) A hydrolyzable organosilane having a general formula represented by SiX ₄ (X is a hydrolyzable group).
(B) A hydrolyzable organosilane having a water repellent group in the straight chain portion and having two or more silica atoms bonded to an alkoxy group in the molecule.
(C) Hydrolyzable organosilane having a fluorine-substituted alkyl group.

Thereby, an antireflection layer having high antireflection properties and excellent chemical resistance and antifouling properties can be formed.

However, when an antireflection layer is provided on a transparent substrate installed outdoors, there is a problem that the antireflection layer is easily deteriorated by being exposed to ultraviolet rays or salt. Moreover, since the high intensity | strength is requested | required of the base material installed outdoors, this base material is often formed from the tempered glass containing an alkali ion. When an antireflection layer is provided on a substrate formed of such tempered glass, there is a problem that the antireflection layer is easily deteriorated by being attacked by an alkali component.

Therefore, it is required to improve the weather resistance and alkali resistance while maintaining good transparency of the antireflection layer.

JP 2007-99828 A

The present invention has been made in view of the above reasons, and can form a coating film having high weather resistance and alkali resistance and sufficiently high transparency, and is particularly suitable for forming an antireflection layer. It is an object to provide a coating composition.

Another object of the present invention is to provide a coated product provided with a film formed from a cured product of this coating composition.

The coating composition according to the present invention contains a curable resin and silica-based metal oxide particles,
The curable resin consists of at least one of a hydrolytic condensable compound and a partial hydrolyzate thereof,
The molecule of the hydrolytic condensable compound has an organic chain and a hydrolyzable silyl group bonded to each of both ends of the organic chain,
The organic chain is composed of one or more groups selected from an alkylene group that may have a substituent, a fluoroalkylene group that may have a substituent, and an ether group, and the organic chain is the alkylene At least one of a group and the fluoroalkylene group.

It is preferable that the hydrolytic condensable compound includes a compound represented by the following structural formula (1).

R ¹ _q X _3-q Si— (CH ₂ ) _p —SiX _3-r R ¹ _r (1)
R ¹ represents an organic group, and when a plurality of R ¹ are present in one molecule, these may be the same as or different from each other. X represents a hydrolyzable group, and a plurality of X in one molecule may be the same as or different from each other. p represents an integer of 1 to 10. q represents an integer of 0 to 2. r represents an integer of 0-2.

The coated product according to the present invention includes a film formed from the coating composition.

When a film is formed from the coating composition according to the present invention, the film exhibits sufficiently high weather resistance and alkali resistance while having sufficiently high transparency.

It is a schematic sectional view of a coated article showing an example of an embodiment of the present invention.

The coating composition according to this embodiment contains a curable resin and silica-based metal oxide particles.

The curable resin is a resin component that is cured when a film is formed from the coating composition, and a cured product of the curable resin constitutes a matrix of the film.

The curable resin is composed of at least one of a hydrolytic condensable compound and a partial hydrolytic condensate thereof. The molecule of the hydrolytic condensable compound has an organic chain and a hydrolyzable silyl group bonded to each of both ends of the organic chain. The organic chain is composed of one or more groups selected from an alkylene group which may have a substituent, a fluoroalkylene group which may have a substituent, and an ether group. Furthermore, the organic chain has at least one of an alkylene group which may have a substituent and a fluoroalkylene group which may have a substituent. That is, when the organic chain consists only of an alkylene group, when it consists only of a fluoroalkylene group, when it consists of an alkylene group and a fluoroalkylene group, when it consists of two or more alkylene groups and an ether group, two or more fluoroalkylene groups And an ether group, as well as an alkylene group, a fluoroalkylene group and an ether group. In this specification, an ether group is a divalent group consisting of only oxygen, and the ether group is bonded to a carbon atom in an alkylene group or a fluoroalkylene group.

When the coating composition contains such a curable resin, high transparency of the film formed from the coating composition is maintained, the mechanical strength of the film is improved, and the film has high weather resistance. Alkali resistance and salt water resistance are imparted. This is presumably because the organic chain as described above is present in the curable resin, so that the ratio of siloxane bonds in the coating is reduced. That is, it is presumed that the durability of the coating is improved because the ratio of siloxane bonds that are easily broken by an attack from the outside decreases.

In the hydrolytic condensable compound, the hydrolyzable silyl group is represented, for example, by the following formula (2).

-SiX _3-m R ¹ _m (m is an integer of 0 to 2) (2)
X in Formula (2) represents a hydrolyzable group, and when a plurality of Xs are present, the plurality of Xs may be the same as or different from each other. R ¹ represents a monovalent hydrocarbon group, and when a plurality of R ¹ are present, the plurality of R may be the same or different from each other.

R ¹ is not particularly limited as long as it is a monovalent hydrocarbon group, but is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms. Preferable specific examples of R ¹ include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group. When R ¹ has 3 or more carbon atoms, R ¹ may be linear, such as n-propyl group, n-butyl group, etc., isopropyl group, isobutyl group, t-butyl group, etc. You may have a branch like this.

X represents an alkoxyl group, an acetoxy group, an oxime group (—O—N═C—R (R ′)), an enoxy group (—O—C (R) ═C (R ′) R ″), an amino group, An aminoxy group (—O—N (R) R ′), an amide group (—N (R) —C (═O) —R ′) (in these groups, R, R ′, R ″ are independently A hydrogen atom or a monovalent hydrocarbon group), halogen and the like.

When X is an alkoxy group, the hydrolyzable silyl group is represented, for example, by the following formula (2a).

-Si (OR ² ) _3-m R ¹ _m (m is an integer from 0 to 2) (2a)
R ¹ in the formula (2a) represents a monovalent hydrocarbon group as in the case of the formula (2), and when a plurality of R ¹ are present, the plurality of R may be the same or different from each other. Good. R ² in the formula (2a) represents a monovalent hydrocarbon group as in the case of the formula (2). When a plurality of R ² are present, the plurality of R may be the same or different from each other. Good.

R ² is not particularly limited as long as it is a monovalent hydrocarbon group, but is preferably a monovalent hydrocarbon group having 1 to 8 carbon atoms. Preferable specific examples of R ² include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group. When R ² has 3 or more carbon atoms, R ² may be linear, such as n-propyl group, n-butyl group, etc., isopropyl group, isobutyl group, t-butyl group, etc. You may have a branch like this.

In the molecule of the hydrolytic condensable compound, a hydrolyzable silyl group is bonded to each of both ends of the organic group as described above, but the hydrolyzable silyl group is further added to the organic group at other positions. May be bonded to. That is, the molecule of the hydrolytic condensable compound may have two or more hydrolyzable silyl groups. For example, when the organic group has an alkylene group, a hydrolyzable silyl group may be bonded to the alkylene group as a substituent, and when the organic group has a fluoroalkylene group, the fluoroalkylene group is hydrolyzed as a substituent. Silyl group may be bonded. The upper limit of the number of hydrolyzable silyl groups in the molecule of the hydrolytic condensable compound is not particularly limited.

The length of the organic chain in the molecule of the hydrolytic condensable compound is not particularly limited, but it is preferable that the number of atoms sequentially bonded in series in this organic chain is in the range of 1 to 10. In this case, the amount of the organic component in the cured product of the hydrolytic condensable compound is moderately suppressed, so that the UV resistance of the film formed from the coating composition is sufficiently high. In addition, good compatibility between the hydrolytic condensable compound and other components such as a solvent in the coating composition is ensured, so that the transparency of the film formed from the coating composition becomes sufficiently good and the film The appearance unevenness is less likely to occur.

It is preferable that the hydrolysis-condensable compound includes a compound represented by the following structural formula (1). In this case, the alkali resistance, salt water resistance, and UV resistance of the film formed from the coating composition are very good, and the transparency of the film is sufficiently high.

R ¹ _q X _3-q Si— (CH ₂ ) _p —SiX _3-r R ¹ _r (1)
R ¹ represents an organic group, and when a plurality of R ¹ are present in one molecule, these may be the same as or different from each other. X represents a hydrolyzable group, and a plurality of X in one molecule may be the same as or different from each other. Details of R ¹ and X in the formula (1) are the same as those in the formula (2).

P in the formula (1) represents an integer of 1 to 10, particularly preferably an integer of 1 to 5. When this p is 10 or less, the amount of the organic component in the cured product of the hydrolytic condensable compound is moderately suppressed, and thus the UV resistance of the film formed from the coating composition is sufficiently increased. In addition, good compatibility between the hydrolytic condensable compound and other components such as a solvent in the coating composition is ensured, so that the transparency of the film formed from the coating composition becomes sufficiently good and the film The appearance unevenness is less likely to occur.

Q in the formula (1) represents an integer of 0 to 2, and r represents an integer of 0 to 2. q and r are preferably 0 or 1, and more preferably 0.

The ratio of the compound represented by the structural formula (1) with respect to the entire hydrolytic condensable compound is not particularly limited, but is preferably in the range of 20 to 100% by mass, and particularly in the range of 50 to 100% by mass. preferable.

The compound that the hydrolytic condensable compound can contain in addition to the compound represented by the structural formula (1) is not particularly limited, but specific examples thereof include compounds represented by the following formulas (11) to (14). .

It is preferable that the coating composition does not contain a material constituting the matrix of the film other than the curable resin. That is, the coating composition preferably contains only the curable resin as a material constituting the matrix of the film.

In addition, as long as the high weather resistance, alkali resistance, salt water resistance, etc. of the film formed from the coating composition are ensured, the coating composition is a material other than the above curable resin as a material constituting the film matrix. For example, a hydrolyzable organosilane represented by SiX ₄ (X is a hydrolyzable group), a hydrolyzed condensate thereof (polysiloxane), an epoxy silane, or the like may be further contained. However, when these materials are mixed in the coating composition, the durability of the film is lowered or the mechanical strength of the film is lowered. For this reason, even when the coating composition contains a material that constitutes the matrix of the film in addition to the curable resin, the ratio may be less than 5% by mass with respect to the entire material that constitutes the matrix of the film. preferable.

On the other hand, the silica-based metal oxide particles can lower the refractive index of the film formed from the coating composition, and can also increase the strength of the film. In the film formed from the coating composition, the silica-based metal oxide particles are dispersed in a matrix composed of a cured product of the curable resin.

Examples of silica-based metal oxide particles include non-hollow particles and hollow particles. Non-hollow particles are particles that do not have cavities inside. The hollow particles are particles having an outer shell formed of a silica-based metal oxide and having a hollow inside the outer shell.

The non-hollow particles are not particularly limited, but include silica particles having no cavities inside. When the coating composition contains the silica particles, the mechanical strength of the film formed from the coating composition is improved, and the surface smoothness and crack resistance of the film can be improved. The form of the silica particles is not particularly limited, and may be, for example, a powder form or a sol form. When the silica particles are in a sol form, that is, when colloidal silica is used, it is not particularly limited. For example, water-dispersible colloidal silica, alcohol or other hydrophilic organic solvent-dispersible colloidal silica, etc. Is used. Generally, such colloidal silica contains 20 to 50% by mass of silica as a solid content, and the content of silica particles in the coating composition can be determined from this value. The content of the silica particles in the coating composition is not particularly limited, but is preferably in the range of 0.1 to 30% by mass with respect to the total solid content in the coating composition. As described above, when the content of the silica particles is 0.1% by mass or more, the mechanical strength of the coating is sufficiently improved, and the surface smoothness and crack resistance of the coating are sufficiently improved. When the content is 30% by mass or less, an increase in the refractive index of the film is moderately suppressed.

In addition, examples of the hollow particles include hollow silica particles. The hollow silica particles are particles having an outer shell (shell) made of a silica-based inorganic oxide and having a cavity formed therein. The outer shell made of silica-based inorganic oxide is formed of, for example, silica alone, or a composite oxide made of silica and an inorganic oxide other than silica, or a layer made of silica and a layer made of composite oxide. It has a two-layer structure. The outer shell may be porous in which pores are formed, or the cavity may be sealed by closing the pores in the outer shell as shown below.

The outer shell may include a plurality of layers including a first layer and a second layer covering the first layer. In this case, the pores formed in the first layer are closed by the second layer, thereby densifying the outer shell and sealing the cavity inside the outer shell.

The thickness of the first layer is preferably in the range of 1 to 50 nm, particularly preferably in the range of 5 to 20 nm. When the thickness of the first layer is 1 nm or more, the strength of the outer shell is sufficiently high and the shape of the hollow particles is maintained. Further, when the second layer is formed, the partial hydrolyzate of the organosilicon compound is difficult to enter the pores of the core particles, and the core particle constituent components are easily removed. Further, when the thickness of the first layer is 50 nm or less, the ratio of the cavities in the hollow silica particles is kept moderate, and thus the refractive index of the coating is sufficiently reduced by the hollow silica particles.

The total thickness of the outer shell is preferably in the range of 1/50 to 1/5 of the average particle diameter of the hollow silica particles. In addition, the thickness of the second layer is preferably in the range of 20 to 49 nm, particularly for densifying the outer shell.

In the cavity, there are a solvent used when the hollow silica particles are prepared, a gas that has entered during drying, and the like. In addition, a precursor material for forming the cavity may remain in the cavity. The precursor material may remain slightly attached to the outer shell or may occupy most of the interior of the cavity. Here, the precursor substance is a porous substance remaining after removing some of the constituent components from the core particles for forming the first layer. As the core particles, porous composite oxide particles made of, for example, silica and an inorganic oxide other than silica are used. Examples of the inorganic oxide include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , Ce ₂ O ₃ , P ₂ O ₅ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ and WO _3. The 1 type (s) or 2 or more types selected are mentioned. Examples of the two or more inorganic oxides include TiO ₂ —Al ₂ O ₃ and TiO ₂ —ZrO ₂ . The solvent or gas is also present in the pores of the porous material. When the removal amount of the constituent components at this time increases, the volume of the cavity increases and hollow silica particles having a low refractive index are obtained. The coating formed from the coating composition containing the hollow silica particles reflects with a low refractive index. Excellent prevention performance.

The average particle diameter of the hollow silica particles is preferably in the range of 5 nm to 2 μm. Thus, when the average particle size is 5 nm or more, the refractive index of the coating is sufficiently reduced by the hollow silica particles. Further, when the average particle size is 2 μm or less, the transparency of the coating is sufficiently high, and the contribution by diffuse reflection (Anti-Glare) is suppressed. When the coating film requires particularly high transparency, the average particle diameter of the hollow silica particles is preferably in the range of 5 to 100 nm. The average particle diameter is a value measured by a dynamic light scattering method.

The ratio of the hollow particles in the coating composition is not particularly limited, but is preferably in the range of 25 to 75% by mass, and more preferably in the range of 30 to 70% by mass with respect to the total solid content in the coating composition. preferable. When the proportion of the hollow particles is 75% by mass or less, the mechanical strength of the coating film formed from the coating composition is sufficiently high, and when this proportion is 70% by mass or less, this effect becomes more remarkable. Further, when the proportion is 25% by mass or more, the refractive index of the coating is sufficiently reduced by the hollow particles, and when this proportion is 30% by mass or more, this effect becomes more remarkable.

The coating composition preferably contains only the above-mentioned silica-based metal oxide particles as a filler, but may contain a filler other than the above-mentioned silica-based metal oxide particles. However, in order to ensure high weather resistance, alkali resistance, salt water resistance, etc. of the film formed from the coating composition, the content of fillers other than silica-based metal oxide particles is preferably as small as possible, and the proportion Is preferably less than 5% by weight based on the total amount of filler in the coating composition.

It is preferable that the coating composition contains water as a solvent or a mixed solvent containing water and a hydrophilic solvent as a solvent. The amount of water in the coating composition is preferably at least the amount required for the hydrolysis reaction of the curable resin. The hydrophilic solvent is not particularly limited, and examples thereof include alcohols such as methanol, ethanol, propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, t-butyl alcohol, diacetone alcohol, and ethylene. Glycol ethers such as glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, ethyl acetate, butyl acetate, ethyl acetoacetate, etc. Esters, xylene, toluene and the like.

The proportion of the solvent in the coating composition is appropriately adjusted according to the viscosity, film formability, etc. required for the coating composition, but is in the range of 10.0 to 99.9% by mass with respect to the entire coating composition. It is preferable that

The coating composition preferably contains a catalyst that accelerates the hydrolysis reaction of the curable resin. Catalysts include acids such as hydrochloric acid, acetic acid and maleic acid, amine compounds such as sodium hydroxide (NaOH), ammonia, triethylamine, dibutylamine, hexylamine, octylamine and dibutylamine, and salts of amine compounds, benzyltriethyl chloride Bases such as quaternary ammonium salts such as ammonium and tetramethylammonium hydroxide, fluoride salts such as potassium fluoride and sodium fluoride, solid acidic catalyst or solid basic catalyst (for example, ion exchange resin catalyst), Metal salts of organic carboxylic acids such as iron-2-ethylhexoate, titanium naphthate, zinc stearate, dibutyltin diacetate, tetrabutoxytitanium, tetra-i-propoxytitanium, dibutoxy- (bis-2,4- Pentanedionate) titanium, di-i Organic titanium esters such as propoxy (bis-2,4-pentanedionate) titanium, tetrabutoxyzirconium, tetra-i-propoxyzirconium, dibutoxy- (bis-2,4-pentanedionate) zirconium, di-i-propoxy (Bis-2,4-pentanedionate) organic zirconium compounds such as zirconium, alkoxyaluminum compounds such as aluminum triisopropoxide, organometallic compounds such as aluminum chelate compounds such as aluminum acetylacetonate complex, γ-aminopropyltri Amino such as methoxysilane, γ-aminopropyltriethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltriethoxysilane Alkyl substituted alkoxysilane is exemplified. These catalysts are used alone or in combination of two or more.

The ratio of the catalyst in the coating composition is appropriately set, but is preferably in the range of 0.1 to 10% by mass with respect to the curable resin.

In addition to the above components, the coating composition may further contain various components within a range not departing from the gist of the present invention.

Such a coating composition is applied onto an appropriate substrate, and the curable resin in the coating composition on the substrate undergoes a hydrolysis reaction and is dried to cure the coating composition on the substrate. A coating composed of an object is provided. Thereby, as shown in FIG. 1, the coated article 3 provided with the base material 2 and the film 1 is obtained.

The substrate is not particularly limited, and examples thereof include an inorganic substrate typified by glass, a metal substrate, and an organic substrate typified by polycarbonate and polyethylene terephthalate. The shape of the substrate is not particularly limited, and examples thereof include a plate shape and a film shape. Furthermore, one or more layers may be formed on the surface of the substrate.

The coating composition is applied to the surface of the substrate by an appropriate method. The application method in this case is not particularly limited. For example, brush coating, spray coating, dipping (dipping, dip coating), roll coating, flow coating, curtain coating, knife coating, spin coating, table coating, sheet coating, Various usual coating methods such as single wafer coating, die coating, and bar coating can be used.

It is preferable that the coating composition applied on the surface of the substrate is dried and then subjected to a heat treatment. This heat treatment further improves the mechanical strength of the coating. The temperature during the heat treatment is not particularly limited, but is preferably in the range of 60 to 300 ° C., and the heating time in this case is preferably in the range of 10 seconds to 20 minutes.

The thickness of the film formed on the surface of the substrate is appropriately set according to the intended use and purpose, but is preferably in the range of 50 to 150 nm.

The film formed on the substrate in this way has high transparency and further has excellent alkali resistance, salt water resistance, and UV resistance. For this reason, even if the coated article provided with such a base material and a film is exposed to the outdoors, the film is unlikely to deteriorate. For this reason, high transparency and strength of the coating are maintained over a long period of time.

Also, a coating film having a low refractive index is formed from the coating composition, and thus this coating film is suitable as an antireflection layer. That is, when the refractive index of the substrate is higher than the refractive index of the coating, the coating is formed directly on the substrate, whereby the antireflection performance is exhibited by the coating. When the refractive index of the substrate is lower than the refractive index of the coating, an intermediate layer having a higher refractive index than the coating is formed on the substrate, and then the coating is formed on the intermediate layer. Thus, the antireflection performance is exhibited by the coating. The intermediate layer may be formed from a known high refractive index material. The refractive index of the intermediate layer is preferably 1.60 or more, and in this case, the difference in refractive index from the coating formed from the coating composition is sufficiently large. Performance is demonstrated. Moreover, in order to relieve the coloring of the film, the intermediate layer may be composed of a plurality of layers having different refractive indexes.

As an example of a transparent substrate when a film formed from the coating composition is used as an antireflection layer, a substrate constituting the outermost surface of the display device, an automobile side mirror, a front glass, a side glass, a rear glass, Other examples include vehicle glass, building glass, and a base material constituting the outermost surface of the solar cell. Since the film formed from the coating composition has alkali resistance, salt water resistance, and UV resistance, the coating composition is used to form a base material that constitutes the outermost surface of a display device installed outdoors, the outermost surface of a solar cell. It is particularly suitable for forming a film on a base material that is installed outdoors such as a base material to be formed. Moreover, since a coating film has high alkali resistance, it is suitable also when a base material is the tempered glass containing an alkali ion.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the invention.

Hereinafter, the present invention will be described by way of examples. The present invention is not limited to these examples.

[Example 1]
5.26 parts by mass of bistriethoxysilylethane (GELEST, Inc., product number SIB1817.0) and 72.23 parts by mass of propylene glycol monomethyl ether were blended, and 7.51 parts by mass of 0.1N nitric acid aqueous solution was added. The mixture was blended and mixed well using a disper to obtain a mixture.

By adding 15.0 parts by mass of a hollow silica particle dispersion (manufactured by JGC Catalysts & Chemicals, isopropyl alcohol solvent, solid content 20%, average particle size 40 nm) to this mixture, hollow silica particles / mixture (condensed compound equivalent) ) Ratio of 60/40 based on solid content. These were mixed well at room temperature, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to prepare a coating composition.

From the time when this coating composition was prepared, this coating composition was allowed to stand for 1 hour. Subsequently, the coating composition was applied on the surface of the tempered glass from which the dirt was previously removed by a spin coater, and this coating composition was heated at 200 ° C. for 10 minutes to form a film having a thickness of 150 nm. . Thereby, the coated product which consists of a tempered glass and the film which covers this tempered glass was obtained.

[Example 2]
4.6 parts by mass of bistriethoxysilylethane (GELEST, Inc., product number SIB1817.0) and 70.39 parts by mass of propylene glycol monomethyl ether were added, and 7.51 parts by mass of 0.1N nitric acid aqueous solution was further added. The mixture was blended and mixed well using a disper to obtain a mixture.

By adding 17.5 parts by mass of a hollow silica particle dispersion (manufactured by JGC Catalysts & Chemicals, isopropyl alcohol solvent, solid content 20%, average particle size 40 nm) to this mixture, hollow silica particles / mixture (condensation compound conversion) ) Ratio of 70/30 based on solid content. These were mixed well at room temperature, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to prepare a coating composition.

[Example 3]
5.92 parts by mass of bistriethoxysilylethane (GELEST, Inc., product number SIB1817.0) and 72.82 parts by mass of propylene glycol monomethyl ether were blended, and 7.51 parts by mass of 0.1N nitric acid aqueous solution was further added. The mixture was blended and mixed well using a disper to obtain a mixture.

By adding 13.75 parts by mass of a hollow silica particle dispersion (manufactured by JGC Catalysts & Chemicals, isopropyl alcohol solvent, solid content 20%, average particle size 40 nm) to this mixture, hollow silica particles / mixture (condensation compound equivalent) ) Ratio of 55/45 on a solid basis. These were mixed well at room temperature, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to prepare a coating composition.

[Example 4]
2.63 parts by mass of bistriethoxysilylethane (GELEST, Inc., product number SIB1817.0) and 69.86 parts by mass of propylene glycol monomethyl ether were added, and 7.51 parts by mass of a 0.1N nitric acid aqueous solution was further added. The mixture was blended and mixed well using a disper to obtain a mixture.

By adding 20 parts by mass of a hollow silica particle dispersion (manufactured by JGC Catalysts & Chemicals, isopropyl alcohol solvent, solid content 20%, average particle size 40 nm) to this mixture, hollow silica particles / mixture (condensation compound equivalent) The ratio was adjusted to a mass ratio of 80/20 based on the solid content. These were mixed well at room temperature, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to prepare a coating composition.

[Example 5]
10.52 parts by mass of bistriethoxysilylethane (GELEST, Inc., product number SIB1817.0) and 76.97 parts by mass of propylene glycol monomethyl ether were blended, and 7.51 parts by mass of 0.1N nitric acid aqueous solution was further added. The mixture was blended and mixed well using a disper to obtain a mixture.

By adding 5.0 parts by mass of a hollow silica particle dispersion (manufactured by JGC Catalysts & Chemicals, isopropyl alcohol solvent, solid content 20%, average particle size 40 nm) to this mixture, hollow silica particles / mixture (condensation compound conversion) ) Ratio was 40/60 mass ratio based on solid content. These were mixed well at room temperature, and further stirred and mixed in a constant temperature atmosphere at 25 ° C. for 1 hour to prepare a coating composition.

[Example 6]
Bistriethoxysilylhexane (GELEST, Inc., product number SIB1832.0) 4.44 parts by mass and propylene glycol monomethyl ether 76.05 parts by mass were blended, and further 0.11 nitric acid aqueous solution 7.51 parts by mass. The mixture was blended and mixed well using a disper to obtain a mixture.

[Comparative Example 1]
5.26 parts by mass of polymethoxysiloxane (Mitsubishi Chemical Co., Ltd., product name methyl silicate 51) and 73.57 parts by mass of propylene glycol monomethyl ether, and 7.51 parts by mass of 0.1N nitric acid aqueous solution These were mixed well using a disper to obtain a mixture.

[Comparative Example 2]
4.6 parts by mass of bistriethoxysilylethane, 0.49 parts by mass of polymethoxysiloxane (Mitsubishi Chemical Corporation, product name methyl silicate 51) and 72.4 parts by mass of propylene glycol monomethyl ether are blended, A mixture was obtained by blending 7.51 parts by mass of 1N nitric acid aqueous solution and mixing them well using a disper.

[Comparative Example 3]
4.6 parts by mass of bistriethoxysilylethane, 0.34 parts by mass of γ-glycidoxypropyltrimethoxysilane (product number TSL8350, manufactured by Momentive Performance Materials Japan GK), propylene glycol monomethyl ether 72. The mixture was obtained by blending 55 parts by mass, further blending 7.51 parts by mass of a 0.1N nitric acid aqueous solution, and mixing them well using a disper.

[Evaluation test]
The following evaluation tests were performed on the coated products obtained in the examples and comparative examples. The results are shown in Table 1 below.

(Refractive index measurement)
The refractive index of the film in the coated product was derived using a simple ellipsometer (manufactured by FILMTRICS, model number F20).

(Abrasion resistance measurement)
The surface of the coating was rubbed with an abrasion tester (manufactured by Shinto Kagaku Co., Ltd., model number HEIDON-14DR, steel wool # 0000, 500 g load, 10 reciprocations). The change in the appearance of the film before and after this test was visually confirmed, and “○” indicates that the remaining amount of the film in the test range is 50% or more, and “×” indicates that the remaining amount is less than 50%. evaluated.

(Transmittance measurement)
Using a spectrophotometer (manufactured by Hitachi, Ltd., model number U-4100), the spectral transmittance in the wavelength range of 300 to 1500 nm when light is irradiated toward the coating is measured, and based on the result Thus, an average value of transmittance in a wavelength range of 400 to 1100 nm was derived. The transmittance in the case of tempered glass alone was 91.3%.

(UV resistance test)
Using a super UV test apparatus (manufactured by Iwasaki Electric Co., Ltd., model number SUV-W151) under the conditions of an atmospheric temperature of 80 ° C. and a humidity of 70 RH%, ultraviolet rays are applied to the coating on the coated product with an intensity of 100 mW / cm ² and an irradiation time of 24 hours. Irradiation was performed under the following conditions.

Subsequently, the transmittance of the coated product was measured by the same method as in the case of “Transmittance measurement”, and the amount of decrease in transmittance compared with the case of “Transmittance measurement” was calculated.

(High temperature and high humidity test)
Using a small environmental test apparatus (manufactured by Espec, model number SH-241), the coated product was exposed to an atmosphere of 85 ° C. and 80% humidity for 500 hours.

According to this result, the light transmittance was good in Examples 1 to 6. Further, the amount of decrease in transmittance after UV irradiation was small, and the UV resistance was high. Moreover, the amount of decrease in the transmittance after the high temperature and high humidity test is small, and therefore, it can be evaluated that even when the alkali component is eluted from the tempered glass, the coating is hardly deteriorated. Thus, the coating films in Examples 1 to 6 exhibited high durability.

Furthermore, in Examples 1 to 4, the refractive index of the coating was greatly reduced and the light transmittance was particularly good. Further, except for Example 4 where the proportion of hollow silica is relatively high, in each Example, the abrasion resistance of the coating is also high. For this reason, the use of the hydrolytic condensable compound specified in this embodiment enables the coating of the coating. It can be evaluated that the strength is improved.

On the other hand, in Comparative Examples 1 and 2 in which a considerable amount of polymethoxysiloxane was contained in the coating composition, the transparency after the high temperature and high humidity test was greatly reduced. Further, in Comparative Example 3 in which a considerable amount of γ-glycidoxypropyltrimethoxysilane was contained in the coating composition, the transparency after the UV resistance test and after the high temperature and high humidity test was greatly reduced. Furthermore, the low abrasion resistance in Comparative Example 3 can be evaluated by the fact that the coating film was softened by using a considerable amount of γ-glycidoxypropyltrimethoxysilane.

1 Coating 2 Base material 3 Painted product

Claims

Containing a curable resin and silica-based metal oxide particles,
The curable resin consists of at least one of a hydrolytic condensable compound and a partial hydrolyzate thereof,
The molecule of the hydrolytic condensable compound has an organic chain and a hydrolyzable silyl group bonded to each of both ends of the organic chain,
The organic chain is composed of one or more groups selected from an alkylene group that may have a substituent, a fluoroalkylene group that may have a substituent, and an ether group, and the organic chain is the alkylene A coating composition having at least one of a group and the fluoroalkylene group.
The coating composition according to claim 1, wherein the hydrolytic condensable compound includes a compound represented by the following structural formula (1).
R 1 q X 3-q Si— (CH 2 ) p —SiX 3-r R 1 r (1)
R 1 represents an organic group, and when a plurality of R 1 are present in one molecule, these may be the same as or different from each other.
X represents a hydrolyzable group, and a plurality of X in one molecule may be the same as or different from each other.
p represents an integer of 1 to 10.
q represents an integer of 0 to 2.
r represents an integer of 0-2.
A coated article comprising a film formed from the coating composition according to claim 1.