JP2001214156A - Article having water- and oil-repellent coated film and its preparation process - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an article and a preparation process using a fluorine coated film 4 which shows a high adhesiveness to a substrate 1, has no pinhole and exerts an excellent water- and oil-repellency at its surface. SOLUTION: The surface of the substrate 1 is brought into contact and allowed to react with a mixture of a perfluoroalkyl alkoxysilane and a completely hydrolyzable silane 3. The substrate 1 is a substrate chosen from the group consisting of glass, ceramics, metals, plastics and a substrate covered with an inorganic coated film on which a non-wetting surface 4 is formed. The completely hydrolyzable silane is represented by the formula: Si(OA)4 (wherein A is H or an alkyl group). The perfluoroalkyl alkoxysilane is preferably represented by the formula: CF3-(CF2)n-R-SiYq(OA)3-q [wherein (n) is 0 or an integer; R is an alkylene group or the like; and OA is an alkoxy group (provided that A is H or an alkyl group)].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water / oil repellent coating (also referred to as a non-wetting surface layer) and a method for producing the same. More specifically, when modifying the surface of the substrate to a non-wetting surface, the substrate surface is brought into contact with a mixture of perfluoroalkyl alkoxysilane and a completely hydrolyzable silane to cause a dealcoholization reaction to give the substrate surface a water- and oil-repellent property. The present invention relates to an invention for forming a film.

[0002]

2. Description of the Related Art Conventionally, buildings, electrical appliances, vehicles, industrial equipment, mirrors, spectacle lenses, and the like have been required to have an ultra-thin coating having heat resistance, weather resistance, abrasion resistance and an antifouling function. .

[0003] As a method for producing such a coating film for the purpose of water / oil repellency / antifouling, a method of baking a fluorocarbon polymer is known at present.

In this method, the surface of a substrate is roughened by a sand brush, a wire brush, chemical etching, or the like, and a primer or the like is applied. Then, a fluorocarbon-based fine powder such as polytetrafluoroethylene is suspended in ethanol or the like. In general, a coating material is applied, dried, baked at about 400 ° C. for about 1 hour (baking treatment), and a fluorocarbon polymer is baked on the substrate surface.

[0005]

However, while this method is easy to manufacture, the polymer and the substrate are merely bonded by the anchor effect only, so that the adhesion to the substrate is limited, and the durability is limited. The sex was inferior. Also,
Since the surface of the coating film was baked at a high temperature of 400 ° C., the surface was flattened and a good water / oil repellent surface could not be obtained. Therefore, this method is not sufficient as a method for manufacturing a device that requires a water- and oil-repellent coating film such as an electric appliance, an automobile, and an industrial device.

In view of the above-mentioned drawbacks of the conventional method, an object of the present invention is to provide a method for producing a fluorine-based coating film having good adhesion to a substrate, no pinholes, and excellent surface water / oil repellency. Another object of the present invention is to improve the performance of equipment requiring heat-resistant, weather-resistant, and wear-resistant coatings having excellent water and oil repellency, such as buildings, electric appliances, vehicles, and industrial equipment.

[0007]

In order to achieve the above-mentioned object, an article having a water- and oil-repellent coating according to the present invention is characterized in that at least a part of the surface of the substrate comprises a perfluoroalkylalkoxysilane and a completely hydrolyzable silane. Wherein the substrate has been treated with a composition comprising a mixture of
Ceramic, metal, plastic substrate, and at least one selected from a substrate coated with an inorganic coating,
The completely hydrolyzable silane is Si (OA)
₄ (A is H or an alkyl group).

Next, a method for producing a water- and oil-repellent coating of the present invention comprises contacting the surface of a substrate with a mixture of a perfluoroalkylalkoxysilane and a completely hydrolyzable silane. The substrate is glass,
A method of forming a non-wetting surface on a substrate selected from the group consisting of ceramics, metals, plastics, and their substrates coated with an inorganic coating, wherein the fully hydrolyzable silane comprises Si (OA ) ₄ (A is H or an alkyl group).

In the above article or method, the perfluoroalkylalkoxysilane has the general formula CF _3-
(CF ₂ ) _n -R-SiY _q (OA) _3-q (n is 0 or an integer, R is an alkylene group, an ethylene group, an acetylene group, or a substituent containing an Si or oxygen atom, X is an H or an alkyl group , A cycloalkyl group, a substituent selected from an allyl group or a derivative thereof, OA is an alkoxy group (provided that
A is a compound represented by H or an alkyl group), and q is a compound represented by 0, 1 or 2), from the viewpoint of improving antifouling properties.

Here, the perfluoroalkylalkoxysilane is preferably at least one selected from the following compounds.

(1) CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OC
_{H 3) 3 (2) CF} 3 (CF 2) 7 (CH 2) 2 Si (OC 2 H 5) 3 (3) CF 3 (CH 2) 2 Si (CH 3) 2 (CH 2) 15 Si
(OCH ₃ ) ₃ (4) F (CF ₂ ) ₈ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉
Si (OCH ₃ ) ₃ (5) CF ₃ COO (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ Further, if a glassy silica film is used as an inorganic coating, it is convenient to increase durability.

Further, it is preferable that the glassy silica film is formed by applying silicate glass on the surface of a glass substrate and further performing a heat treatment or a plasma ashing treatment.

Furthermore, it is preferable for improving the water / oil repellency that the outermost surface of the substrate is uneven on the order of submicron to micron.

Further, the surface of the substrate and the perfluoroalkyl
When a mixture of an alkoxysilane and a completely hydrolyzable silane is treated by a dealcoholization reaction, the durability is preferably improved.

It is preferable to use a glassy silica film as the inorganic coating because durability can be improved.

In the present invention, "perfluoroalkyl alkoxysilane" is also referred to as "perfluoroalkyl alkoxysilane".

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment of the present invention comprises a step of applying a solvent containing a substance containing a fluorocarbon group and an alkoxysilyl group, or a step of applying a solvent containing a substance containing a fluorocarbon group and an alkoxysilyl group. completely hydrolyzable SiY _t (O as a crosslinking agent for said substance
A) A process including the step of adding _4-t (Y is a substituent such as an alkyl group, OA is an alkoxy group (where A is H or an alkyl group) and t is 0, 1 or 2), and a step of performing a heat treatment .

In the above-mentioned method, a step of forming irregularities on the surface of the substrate in advance and contacting the substrate with a non-aqueous solvent containing a substance containing a plurality of chlorosilyl groups to contain a plurality of hydroxyl groups and the plurality of chlorosilyl groups on the surface of the substrate are provided. Reacting the substance with a chlorosilyl group of the substance to deposit the substance on the surface of the substrate, and washing and removing the excess chlorosilyl group remaining on the substrate using a non-aqueous organic solvent, and then reacting with water. Alternatively, a silica monomolecular film mainly composed of a siloxane bond composed of a substance containing a plurality of silanol groups (this film is also referred to as a silica underlayer) may be formed on the substrate.

In the above method, in the step of forming a silica underlayer on the surface of the substrate, a method in which fine particles and silicate glass are mixed and applied to the surface of the substrate, followed by heating and baking all the substrates, an electrolytic etching method, a chemical etching method At least one method selected from the group consisting of sand blasting, sputtering, and rubbing is used.

In the above method, the substance containing a fluorocarbon group and an alkoxysilyl group is CF _{3-
(CF 2) n -R-SiY} q (OA) 3-q ( perfluoroalkyl alkoxysilanes of perfluoroalkyl alkyl silane; n is 0 or an integer, R represents an alkylene group, an ethylene group, an acetylene group or Si,,
A substituent containing an oxygen atom, X is a substituent selected from H or an alkyl group, a cycloalkyl group, an allyl group or a derivative thereof, OA is an alkoxy group (where A is H or an alkyl group), and q is 0, 1 Or use 2).

According to the embodiment of the present invention, since the chemically adsorbed monomolecular film containing fluorine is formed at least through a siloxane bond on the surface of the substrate on which the silica base layer is formed, A fluorine-based coating film having good and no pinholes and having excellent water and oil repellency (non-wetting), heat resistance, weather resistance, abrasion resistance and the like can be obtained.

Further, in the present invention, glass fine particles and silicate glass are mixed and coated on the surface of a fluorocarbon-based coating film forming substrate in advance, and then baked to form a glassy silica base layer having an irregular surface with a submicron to micron order. Or a step of roughening the substrate by etching or sandblasting the substrate itself, has the effect of forming fine irregularities on the surface of the fluorocarbon-based coating film formed in a later step. Therefore, it is possible to form a fluorocarbon-based coating film (hereinafter, also referred to as a fluorocarbon-based polymer film) having any surface irregularities and extremely excellent water / oil repellency.

At this time, since the polymer having a fluorocarbon group is chemically bonded to the base via -O-, the adhesion is extremely excellent.

In the method of applying fine particles, the roughness of the surface can be controlled by the diameter and amount of the fine particles added to the silicate glass.

Furthermore, after the step of forming irregularities on the surface, the substrate is brought into contact with a non-aqueous solvent in which a substance containing a plurality of chlorosilyl groups is mixed to form a chlorosilyl group on the surface of the substrate and the substance containing a plurality of chlorosilyl groups. And a step of causing the substance to precipitate on the surface of the substrate by reacting with water and washing and removing a substance containing a plurality of excess chlorosilyl groups remaining on the substrate using a non-aqueous organic solvent, and then reacting with water. Forming a pure silica monomolecular film containing a plurality of silanol groups on the substrate; and CF _3- (C
F ₂ ) _n -R-SiY _q (OA) _3-q (where n, R,
p and q are the same as described above. If the step of chemically adsorbing the surfactant on the substrate surface and accumulating the monomolecular adsorption film is performed,
This has the effect of producing a fluorocarbon-based (fluorocarbon-based) chemically adsorbed monomolecular film having a higher molecular adsorption density.

Further, in order to adjust the hardness of the formed fluorocarbon polymer film, in the case of a solvent mixed with a substance containing a fluorocarbon group and an alkoxysilyl group, SiY _t (OA) _4-t ( Y is a substituent such as an alkyl group, OA is an alkoxy group, (where A is H
Alternatively, by using 0, 1 or 2) for the alkyl group) t, 3 in the fluorocarbon-based polymer film thus formed is used.
The dimensional crosslinking density can be adjusted, and the effect of controlling the hardness of the non-wetting fluorocarbon polymer film formed on the surface can be obtained.

[0027]

The substrates to which the present invention can be applied include glass,
Although there are various types such as ceramics, metals, and plastics, it is most preferable to apply to a glass substrate. This will be described below with reference to an example. In the following examples, the unit “%” means “% by weight”.

[0028]

Example 1 As shown in FIG. 1, after forming a glassy silica base layer having an uneven surface on a substrate, an alcohol solvent (for example, CF _3-) mixed with a substance containing a fluorocarbon group and an alkoxysilyl group was used. (CF ₂ ) _n -R-SiY
_q (OA) _3-q (n is 0 or an integer, R is an alkylene group,
An ethylene group, an acetylene group, a substituent containing Si or an oxygen atom, Y is a substituent such as H or an alkyl group, OA is an alkoxy group (where A is H or an alkyl group), q
When 0 or 1 or 2) is dissolved in methanol at a concentration of several percent) and baking is performed at 200 ° C. for about 30 minutes, the glass-like silica underlayer 3 has an exposed —OH group on the surface. Therefore, the alkoxy group of the fluorine-containing alkoxysilane-based surfactant and the -OH group undergo a dealcoholization reaction to form a bond of -Si (O-) ₃ on the surface, and the uneven glassy silica base layer surface is formed. A siloxane fluorocarbon polymer film containing fluorine was formed.

For example, CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si
Using (OCH ₃ ) ₃ , an ethanol solution dissolved at a concentration of about 1% was prepared, and a substrate on which a polysiloxane coating film having many SiOH bonds (this film is also a silica base film) was formed. When applied on the surface and baked at 200 ° C. for about 30 minutes, CF ₃ CH ₂ O (CH ₂ ) ₁₅ S
Bonds of i (O-) ₃ were generated, and a fluorocarbon polymer film 4 having a thickness of 1 to 5 microns having irregularities of about 10 microns was produced (FIG. 2). In addition, this coating film hardly peeled off even when the goth test was performed.

At this time, SiY _t (OA) _4-t (Y is a substituent such as an alkyl group, and OA is an alkoxy group) is used as a crosslinking agent for the substance in a solvent in which a substance containing a fluorocarbon group and an alkoxysilane group is mixed. (Where A is H or an alkyl group) t is 0 or 1 or 2;
Is a completely hydrolyzable silane. ) (For example, 5% by weight of Si (OCH ₃ ) ₄ ), the bond of CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (O—) ₃ is changed to that of —Si (O—) ₃ . Cross-linking was performed three-dimensionally through the bond, and a fluorocarbon polymer film having a hardness about 2 to 2.5 times as high as that obtained when Si (OCH ₃ ) ₄ was not added was produced.

By the way, when the water droplet 5 is dropped on the fluorocarbon polymer film having the irregularities of about 10 μm on the surface thus formed, the water droplet comes into contact with the fluorocarbon polymer film only at the projections. The water repellency is extremely high as shown in Fig.
35 to 140 degrees.

At this time, when 10% by weight of Si (OC ₃ H ₇ ) ₄ is added as a cross-linking agent to a substance containing a substance containing a fluorocarbon group and an alkoxysilane group, about four times as much A fluorocarbon-based polymer film having a hardness of 5 was produced. In addition, a similar coating is formed using a fluorocarbon polymer (polytetrafluoroethylene).
When a non-aqueous solvent mixed with a substance containing a fluorocarbon group and an alkoxysilane group in which 20% of the fine particles were further dispersed and added was used, the hardness was almost the same as the conventional one, but the adhesion was extremely excellent as compared with the conventional one. A fluorocarbon polymer film having high water and oil repellency was produced.

Further, in the above embodiment, C is used as the reagent.
_{F 3 CH 2 O (CH 2} ) 15 Si (OCH 3) 3, CF 3 - (C
Although F ₂ ) _n -R-SiY _q (OA) _3-q was used, if an ethylene group or an acetylene group was added to or incorporated in the alkyl chain portion, it could be irradiated with an electron beam of about 5 megarads after coating film formation. Since the crosslinking can be performed, a coating film having a hardness of about 10 times can be easily obtained.

As a fluorocarbon surfactant,
In addition to the above, CF_Three(CF_Two) ₇(CH_Two)_TwoSi
(OC_TwoH_Five)_Three, CF_Three(CH_Two)_TwoSi (CH_Three)_Two(CH
_Two)_FifteenSi (OCH_Three)_Three, F (CF_Two)₈(CH_Two)_TwoSi
(CH_Three)_Two(CH_Two)₉Si (OCH_Three)_Three, CF_ThreeCOO
(CH_Two)_FifteenSi (OC_TwoH_Five)_ThreeEtc. are available.

[0035]

As described above, when the method of the present invention is used, ceramics of metals and metal oxides such as Al, Cu, and stainless steel, or glass and plastic substrates can be used.
An excellent fluorocarbon monomolecular film having a water- and oil-repellent film can be formed at a high density without pinholes in a state of being chemically bonded to a substrate. Therefore, there is an effect that a high-performance fluorocarbon-based coating having extremely high durability and excellent water and oil repellency can be provided.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view illustrating a manufacturing process of a water- and oil-repellent coating of Example 1 of the present invention.

FIG. 2 is a conceptual cross-sectional view illustrating a process of manufacturing a water- and oil-repellent coating according to a first embodiment of the present invention.

FIG. 3 is a conceptual cross-sectional view of a case where water droplets are dropped on the water- and oil-repellent coating of Example 1 of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Fine particles 3 Silicate glass film 4 Polymer film-like water- and oil-repellent film 5 Water droplet

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 7/04 CEZ C08J 7/04 CEZZ C08L 83/06 C08L 83/06 83/08 83/08

Claims (14)

[Claims] At least a portion of the surface of a substrate is treated with a composition comprising a mixture of a perfluoroalkylalkoxysilane and a fully hydrolyzable silane, wherein the substrate is a glass, ceramic, metal, or plastic substrate. And at least one selected from a substrate coated with an inorganic coating, wherein the completely hydrolyzable silane is Si (OA)
_4. An article having a water- and oil-repellent coating represented by the formula (A is H or an alkyl group). 2. A method according to claim 1, wherein the perfluoroalkylalkoxysilane has the general formula CF ₃ — (CF ₂ ) _n —R—SiY _q (OA)
_3-q (n is 0 or an integer, R is an alkylene group, an ethylene group, an acetylene group, or a substituent containing Si or an oxygen atom, X is H or an alkyl group, a cycloalkyl group, an allyl group, or a derivative thereof. OA is an alkoxy group (where A is H or an alkyl group), q
The article having the water / oil repellent coating according to claim 1, wherein is a compound represented by 0, 1 or 2). 3. The article having a water / oil repellent coating according to claim 1, wherein the perfluoroalkyl alkoxysilane is at least one selected from the following compounds. (1) CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ (2) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ (3) CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ Si
(OCH ₃ ) ₃ (4) F (CF ₂ ) ₈ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉
Si (OCH ₃ ) ₃ (5) CF ₃ COO (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ 4. The article having a water / oil repellent coating according to claim 1, wherein the inorganic coating is a glassy silica coating. 5. The water-repellent material according to claim 1, wherein the glassy silica film is formed by applying a silicate glass to a surface of a glass substrate and further performing a heat treatment or a plasma ashing treatment. An article having an oily coating. 6. The article having a water- and oil-repellent coating according to claim 1, wherein the outermost surface of the substrate has irregularities on the order of submicron to micron. 7. The water / oil repellency according to claim 1, wherein the surface of the substrate is treated by a dealcoholization reaction using a mixture of a perfluoroalkylalkoxysilane and a completely hydrolyzable silane. Articles having a coating. 8. The method according to claim 8, wherein the surface of the substrate is a perfluoroalkyl
Contacting with a mixture of an alkoxysilane and a fully hydrolyzable silane, wherein said substrate is selected from the group consisting of glass, ceramic, metal, plastic, and those substrates coated with an inorganic coating. A method for forming a non-wetting surface on a substrate, wherein the completely hydrolyzable silane comprises Si (OA)
_4. A method for producing an article having a water / oil repellent film, wherein A is H or an alkyl group. 9. The perfluoroalkylalkoxysilane has the general formula CF ₃ — (CF ₂ ) _n —R—SiY _q (OA)
_3-q (n is 0 or an integer, R is an alkylene group, an ethylene group, an acetylene group, or a substituent containing Si or an oxygen atom, X is H or an alkyl group, a cycloalkyl group, an allyl group or a derivative thereof. OA is an alkoxy group (where A is H or an alkyl group), q
9. The method according to claim 8, wherein is a compound represented by 0, 1 or 2). 10. The method according to claim 8, wherein the perfluoroalkyl alkoxysilane is at least one selected from the following compounds. (1) CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si (OCH ₃ ) ₃ (2) CF ₃ (CF ₂ ) ₇ (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ (3) CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₁₅ Si
(OCH ₃ ) ₃ (4) F (CF ₂ ) ₈ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉
Si (OCH ₃ ) ₃ (5) CF ₃ COO (CH ₂ ) ₁₅ Si (OC ₂ H ₅ ) ₃ 11. The method according to claim 8, wherein the inorganic coating is a vitreous silica film. 12. The glassy silica film is formed by applying silicate glass to the surface of a glass base material and further performing a heat treatment or a plasma ashing treatment.
2. The method according to 1. 13. The method according to claim 8, further comprising the step of processing the outermost surface of the base into irregularities on the order of submicron to micron.
3. The method according to any of 2. 14. The method according to claim 8, wherein the substrate surface is subjected to a dealcoholation reaction with a mixture of a perfluoroalkylalkoxysilane and a completely hydrolyzable silane.