JPH08295845A - Coating composition and production of laminate - Google Patents

Abstract

PURPOSE: To obtain a coating composition comprising a specific aminoalkylalkoxysilane compound, water, an organic solvent, an acid and functional fine particles, useful for forming a transparent coating film excellent in wear resistance, water repellency, stain resistance, weather resistance, antimicrobial resistance, etc. CONSTITUTION: This coating composition comprises (A) an aminoalkylalkoxysilane compound of the formula (Y is an amino group- containing organic group; Y<1> is a hydrocarbon group; R is a 1-5C alkyl; (m) is an integer of 1-5; (n) is an integer of 0-2) (especially preferably γ- aminopropyltriethoxysilane), (B) water, (C) an organic solvent, (D) an acid (especially preferably methyl alcohol) and (E) functional fine particles (preferably fluororesin fine particles) and has pH6.5 to pH8.0. The blending ratio of the components is 0.5-300 pts.wt. of the component A, 0.5-300 pts.wt. of the component B, 0.5-300 pts.wt. of the component C and 0.3-30 pts.wt. of the component D based on 1 pt.wt. of the component A and the amount of the composition E is preferably 15-75wt.% based on the whole solid content.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating composition and a method for producing a laminate in which the composition is laminated on a substrate. In particular, a coating composition capable of forming a transparent coating having excellent functions such as abrasion resistance, water repellency, antifouling property, weather resistance, conductivity, ultraviolet absorption and antibacterial property on a substrate and the composition thereof The present invention relates to a method for manufacturing a laminated body in which a product is formed on a base material.

[0002]

2. Description of the Related Art It is known that a transparent film is formed on the surface of a base material that is easily scratched and easily soiled to impart abrasion resistance, water repellency, antifouling property, etc. to the surface of the base material. As a coating composition for forming such a coating, a composition obtained by blending a partial hydrolyzate of alkoxysilane with true spherical organosilicon resin particles or fluorine resin particles (Japanese Patent Laid-Open No. 4-2168).
75, JP-A-4-323280), a mixture of a linear silicone resin and a fluororesin dispersion (JP-A-5-177768), and the like.

However, in these compositions and mixtures, the specific gravity of the true spherical organosilicon resin particles and the fluorine resin particles is different from that of the partial hydrolyzate of alkoxysilane and the silicone resin, so that the particles precipitate. However, there are drawbacks that the dispersibility is poor due to the floating or floating, the coating tends to vary, and the coating lacks transparency.

[0004]

The present invention is intended to solve these problems, and its purpose is to provide abrasion resistance, water repellency, antifouling property, weather resistance, conductivity, ultraviolet absorption and antibacterial properties. Composition containing functional fine particles having excellent functions such as properties and alkoxysilane, having good dispersibility of the above functional fine particles, and capable of forming a transparent coating film having the above functions on a substrate It is to provide a product and a method for producing a laminate in which the coating composition is laminated.

[0005]

The aminoalkylalkoxysilane compound (a) used in the coating composition of the present invention is represented by the following general formula [I].

Embedded image

In the formula, Y represents an organic group having an amino group, and examples thereof include an amino group itself and a substituted amino group in which a hydrogen atom of the amino group is substituted with an aminoalkyl group. Y ¹ represents a hydrocarbon group, and examples thereof include an alkyl group and a substituted alkyl group. R has 1 to 1 carbon atoms
The number of carbon atoms is limited to 1 to 5 because the stability of the coating composition decreases and the long-term storage stability deteriorates when the number of carbon atoms increases. Examples of R include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group,
Examples thereof include n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group and neopentyl group. m is an integer of 1 to 5, n is 0 to 2
Is an integer.

As the compound represented by the general formula [I],
For example, aminomethyltriethoxysilane, N- (β-
Aminoethyl) aminomethyltrimethoxysilane, γ-
Aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ- Aminopropylmethyldimethoxysilane,
N, N-bis [3- (trimethoxysilyl) propyl]
Examples thereof include ethylenediamine and N, N-bis [3- (methyldimethoxysilyl) propyl] ethylenediamine. Of these, γ-aminopropyltriethoxysilane is particularly preferable. The aminoalkylalkoxysilane compound (a) may be used alone or 2
You may use together 1 or more types.

Water (b) used in the coating composition of the present invention is added for the hydrolysis of the aminoalkylalkoxysilane compound (a) and the adjustment of the solid content concentration of the coating composition. When the amount of water (b) is small, sufficient hydrolysis is unlikely to occur, and the concentration of the aminoalkylalkoxysilane compound (a) in the coating composition is high, which makes it unsuitable as a coating composition, and when it is large, it is used for coating. Since the compatibility with other components in the composition becomes poor and the concentration of the aminoalkylalkoxysilane compound (a) may be too low to cover the composition, 1 part by weight of the aminoalkylalkoxysilane compound (a) may be added. On the other hand, 0.5 to 300 parts by weight is preferable.

The organic solvent (c) used in the coating composition of the present invention should be compatible with the aminoalkylalkoxysilane compound (a) and water (b) and should dissolve the acid (d). If it is not particularly limited, for example,
Examples thereof include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, and butyl alcohol, ketones such as acetone and methyl ethyl ketone, and tetrahydrofuran. Methyl alcohol is particularly preferable. These may be used alone or in combination of two or more.

When the amount of the organic solvent (c) is small, the concentration of the aminoalkylalkoxysilane compound (a) in the coating composition is high, which makes it unsuitable as a coating composition. Since the concentration of a) may be too low to be coated, the aminoalkylalkoxysilane compound (a) 1
0.5 to 300 parts by weight is preferable with respect to parts by weight.

The acid (d) used in the coating composition of the present invention is added to adjust the pH of the coating composition to 6.5 to 8.0. By adjusting the pH of the coating composition in this range, the dispersibility of the functional fine particles (e) is dramatically improved. When the pH is out of this range, the dispersibility of the functional fine particles (e) becomes extremely poor, causing aggregation and precipitation.

The acid (d) is not particularly limited, and either an inorganic acid or an organic acid can be used, and examples thereof include inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid, phosphoric acid and acetic acid,
Organic acids such as formic acid may be mentioned. The amount of the acid is added so that the coating composition has a pH of 6.5 to 8.0, but is usually 0.3 to 30 with respect to 1 part by weight of the aminoalkylalkoxysilane compound (a). A range of parts by weight is preferred.

The functional fine particles (e) used in the present invention include abrasion resistance, water repellency, antifouling property, weather resistance, conductivity,
Examples thereof include fine particles and pigments having functions such as ultraviolet absorption and antibacterial properties, but are not particularly limited. The primary particle diameter of the functional fine particles (e) is preferably 0.01 to 10 μm.

As the functional fine particles (e), fluororesin fine particles are preferable. The use of the fine particles of fluororesin imparts abrasion resistance, water repellency, antifouling property and the like to the coating. Examples of the fluororesin fine particles include polytetrafluoroethylene (PTFE) and tetrafluoroethylene-fluoroalkyl vinyl ether copolymer (PF).
A), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), polychlorotrifluoroethylene (CTFE), polyvinylidene fluoride (PVd)
F) and those copolymers of which are in powder form.

If the amount of the above-mentioned functional fine particles (e) becomes small, it becomes impossible to impart the intended function to the coating film,
If the amount is too large, the dispersibility in the coating composition becomes poor and precipitates occur, resulting in variations in the coating and deterioration in transparency. 15 to 75% by weight is preferable. In addition, this solid content means that the coating composition is heated at 350 ° C. in air at 20 ° C.
It refers to the solid content when heat-treated for a minute.

When the above-mentioned functional fine particles (e) are fluororesin fine particles, when the amount is small, it becomes impossible to sufficiently impart functions such as abrasion resistance, water repellency and antifouling property to the film, and when the amount is large, it is for coating. Since the dispersibility in the composition deteriorates and precipitates occur, the coating film varies and the transparency decreases. Therefore, the total solid content of (a) to (e) is 15 to 75. A weight percentage is preferred.

If necessary, one or more additives such as various colorants, fillers such as fumed silica, thickeners, surfactants and ultraviolet absorbers may be added to the coating composition of the present invention. May be.

The method for producing the coating composition of the present invention comprises:
The aminoalkylalkoxysilane compound (a) is not particularly limited, and, for example, after dissolving the aminoalkylalkoxysilane compound (a) in a mixture of water (b) and an organic solvent (c), an acid (d) for pH adjustment is added, A method of adding functional fine particles (e) such as fine particles of fluororesin to the composition in which the pH of the alkoxysilane compound (a) solution is adjusted to 6.5 to 8.0 can be mentioned.

The coating composition of the present invention is applied to a base material and cured to obtain a laminate having a coating film formed on the base material.

The base material is not particularly limited, and examples thereof include metal, glass, plastic and the like. The base material may be a colorless or colored transparent base material or an opaque base material, and the color tone, shape, etc. are not particularly limited.

The coating method is not particularly limited, and examples thereof include spray coating, roll coating, flow coater coating, dip coating, and flow coating.

As the above-mentioned curing method, the curing may be carried out at room temperature or, if necessary, at about 80 to 450 ° C.

Thus, from the coating composition of the present invention, there is no variation on the substrate, the transparency of the substrate is not impaired, and the function of the functional fine particles (e) is
It is possible to manufacture a laminate having a coating film provided with excellent functions such as abrasion resistance, water repellency, antifouling property, weather resistance, conductivity, ultraviolet absorption and antibacterial property.

In the method for producing a laminate of the present invention, the coating composition obtained by using fluororesin fine particles as the functional fine particles (e) in the coating composition of the present invention is applied to a substrate and cured. It is characterized by

In the method for producing a laminate of the present invention, the base material, the coating method, the curing method, etc. are the same as those described above except that the coating composition comprising the fluororesin fine particles as the functional fine particles (e) is used. Of those used to obtain laminates from the coating composition of the present invention.

According to the method for producing a laminate of the present invention, there is no variation on the substrate, the transparency of the substrate is not impaired, and the abrasion resistance,
It is possible to manufacture a laminated body on which a coating film having functions such as water repellency and antifouling property is formed.

[0027]

The coating composition of the present invention is a coating composition comprising an aminoalkylalkoxysilane compound (a), water (b), an organic solvent (c), an acid (d) and functional fine particles (e). Since the pH is adjusted to 6.5 to 8.0, the dispersibility of the functional fine particles (e) is good,
When this coating composition is applied onto a substrate and cured, a coating film having no variations and not impairing the transparency of the substrate can be formed. Further, various functions can be imparted to the coating film depending on the function of the functional fine particles (e).

Further, in the coating composition of the present invention, when fluorine resin fine particles are used as the functional fine particles (e), abrasion resistance, water repellency, antifouling property, etc. are imparted to the coating.

According to the method for producing a laminate of the present invention, the coating composition having the above pH adjusted to 6.5 to 8.0 is used, and the functional fine particles (e) in the coating composition are used. As it uses fine particles of fluororesin, a coating with functions such as abrasion resistance, water repellency and stain resistance is formed on the base material without variation and without impairing the transparency of the base material. The laminated body can be manufactured.

[0030]

Embodiments of the present invention will be described below. The methods for evaluating the dispersion stability of the coating composition and the physical properties of the laminate shown in the results are as follows.

(1) Dispersion Stability With respect to the obtained coating composition, the dispersion stability of the fluororesin fine particles was evaluated as follows. ○ The solution was a uniform solution with no precipitation of fluororesin particles. △ Dispersion of the fluororesin fine particles in the solution was poor and some precipitation occurred. × The fluororesin particles and the solution were separated, and the fluororesin particles were precipitated. (2) Appearance observation The appearance of the obtained laminate was observed and evaluated as follows. ○ It was a homogeneous and transparent film. (Triangle | delta) It was a film | membrane whose haze was 1.0 or more although it was homogeneous. × It was a heterogeneous film with irregularities. (3) Visible Light Transmittance Using the UV / visible spectrophotometer for the obtained laminate, the ratio of the integrated values of the transmittance of visible light of 400 to 700 nm (the state where nothing is present is 100%). It was defined as the visible light transmittance. (4) Contact angle against water With respect to the obtained laminate, the contact angle against pure water was measured by a droplet method using a contact angle meter manufactured by Kyowa Interface Science Co., Ltd. (5) Abrasion resistance test The surface of the obtained laminate was reciprocated 10 times with a load of 500 g using steel wool # 0000, and the degree of scratches was visually evaluated as follows. 4: There were almost no scratches. 3: A little scratched. 2: Deeply scratched. 1: There was a scratch reaching the base material.

(Examples 1 to 5) 9.3 parts by weight of γ-aminopropyltriethoxysilane was added to an aqueous methanol solution in which 15 parts by weight of methanol and 73 parts by weight of ion-exchanged water were mixed, and after stirring, the above aqueous methanol solution was added. 2.7 parts by weight of concentrated nitric acid was added with stirring while cooling with water to obtain a methanol aqueous solution of γ-aminopropyltriethoxysilane having a pH of 6.8. The fluororesin fine particles shown in Table 1 were added to this solution (hereinafter referred to as A-1), and the mixture was further stirred to obtain a coating composition. The mixture of A-1 and the fluororesin fine particles was obtained by coating the obtained coating composition in air at 350 ° C.
Obtained from the solid content obtained from A-1 and the fluororesin fine particles with respect to the total solid content (= the sum of the solid content obtained from A-1 and the solid content obtained from the fluororesin fine particles) when heat-treated for 20 minutes at The solid contents are shown in Table 1
It was blended so as to have the ratio shown in. The details of the fluororesin fine particles shown in Table 1 and Table 2 described later are as follows. THV: Sumitomo 3M, 3M THV fluoroplastic AD-2: Daikin Industries, Ltd. AD-2-CR (PF
A)

This coating composition was applied to a plate glass (float glass manufactured by Central Glass Co., Ltd.) by a flow coating method, and 28
The laminate was heat-treated at 0 ° C. for 1 hour and at 350 ° C. for 20 minutes to be cured to obtain a laminate having a coating film having a thickness of 0.5 μm formed on the plate glass. The dispersion stability of the coating composition and each physical property of the obtained laminate were evaluated based on the evaluation method,
The results are shown in Table 1.

Comparative Examples 1 to 3 In a solution (hereinafter referred to as E-1) consisting of 40 parts by weight of ethyl silicate, 45 parts by weight of ethanol, and 5 parts by weight of 0.036% by weight hydrochloric acid water, Table 2
The fluororesin particles shown in 1 above were added and well stirred to obtain a coating composition. The composition of E-1 and the fluororesin fine particles was prepared by mixing the obtained coating composition in air at 350 ° C. for 20 minutes.
Solid content obtained from E-1 and solid content obtained from fluororesin fine particles with respect to total solid content (= total sum of solid content obtained from E-1 and solid content obtained from fluororesin fine particles) when heat-treated for minutes Were blended in such a manner that the respective ratios were as shown in Table 2. Using this coating composition, a laminated body was obtained in the same manner as in Example 1. The film thickness of the coating was 0.5 μm. The dispersion stability of the coating composition and each physical property of the obtained laminate were evaluated based on the above evaluation methods, and the results are shown in Table 2.

(Comparative Examples 4 and 5) A predetermined amount of fluororesin fine particles shown in Table 2 was added to a silicone resin (KR-311 manufactured by Shin-Etsu Silicone Co., Ltd.) and well stirred to obtain a coating composition. Using this coating composition, a laminated body was obtained in the same manner as in Example 1. The film thickness of the coating is 0.5 μm
Met. The dispersion stability of the coating composition and each physical property of the obtained laminate were evaluated based on the evaluation method,
The results are shown in Table 2.

Comparative Example 6 9.3 parts by weight of γ-aminopropyltriethoxysilane was added to an aqueous methanol solution in which 15 parts by weight of methanol and 73 parts by weight of ion-exchanged water were mixed, and after stirring, the aqueous solution of methanol was cooled with water. While adding 3.2 parts by weight of concentrated nitric acid while stirring, γ-at pH 4.1 was added.
An aqueous solution of aminopropyltriethoxysilane in methanol was used. The fluororesin fine particles shown in Table 2 were added to this solution (hereinafter referred to as A-2) and further stirred.
The fluororesin particles and A-2 were separated and the particles were precipitated.
The mixture of A-2 and the fluororesin fine particles is such that the obtained coating composition is heat-treated in air at 350 ° C. for 20 minutes to obtain a total solid content (= solid content obtained from A-2 and fluororesin fine particles). From the total solid content obtained from A),
The solid contents obtained from No. 2 and the solid contents obtained from the fluororesin fine particles were blended so as to be the ratios shown in Table 2, respectively.

Comparative Example 7 9.3 parts by weight of γ-aminopropyltriethoxysilane was added to an aqueous methanol solution in which 15 parts by weight of methanol and 73 parts by weight of ion-exchanged water were mixed, and after stirring, the aqueous methanol solution was cooled with water. While adding 1.8 parts by weight of concentrated nitric acid while stirring, a methanol aqueous solution of γ-aminopropyltriethoxysilane having a pH of 10 was obtained. The fluororesin fine particles shown in Table 2 were added to this solution (hereinafter referred to as A-3) and further stirred, but the fluororesin fine particles and A-3 were separated and the fine particles were precipitated. The blend of A-3 and the fluororesin fine particles is such that the obtained coating composition is heat-treated in air at 350 ° C. for 20 minutes to obtain a total solid content (= solid content obtained from A-3 and fluororesin fine particles). A-3 with respect to the total of the solid content obtained from
The solid content obtained from the above and the solid content obtained from the fluororesin fine particles were blended so as to be the ratios shown in Table 2, respectively.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

The constitution of the coating composition of the present invention is as described above, the dispersibility of the functional fine particles is good, and when the coating composition is applied and cured on the substrate, the dispersion is not uniform. It is possible to form a coating film that does not impair the transparency of the substrate. Also, depending on the function of the functional particles,
Functions such as abrasion resistance, water repellency, antifouling property, weather resistance, conductivity, ultraviolet absorption and antibacterial property can be imparted to the film.

Further, in the coating composition of the present invention, when fluorine resin fine particles are used as the functional fine particles (e), abrasion resistance, water repellency, antifouling property, etc. are imparted to the coating.

The structure of the method for producing a laminate of the present invention is as described above, and there is no variation on the base material, the transparency of the base material is not impaired, and the abrasion resistance, water repellency and antifouling property are improved. It is possible to manufacture a laminated body on which a coating film having the functions described above is formed.

Claims (3)

[Claims] 1. (a) An aminoalkylalkoxysilane compound represented by the following general formula [I]: (In the formula, Y is an organic group having an amino group, Y ¹ is a hydrocarbon group, R is an alkyl group having 1 to 5 carbon atoms, m is an integer of 1 to 5, and n is an integer of 0 to 2) (b) A coating composition comprising water, (c) an organic solvent, (d) an acid, and (e) functional fine particles and having a pH of 6.5 to 8.0. 2. The coating composition according to claim 1, wherein the functional fine particles are fluororesin fine particles. 3. A method for producing a laminate, which comprises applying the coating composition according to claim 2 to a substrate and curing the composition.