JPH04249146A - Water-repellent oil-repellent stainproof film and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to water-repellent, oil-repellent and stain-proof glass, ceramic, metal and plastic products and methods for producing these products.

0002

[Prior Art] Glass products such as vehicle window glasses and windshields, optical lenses, eyeglass lenses, building window glasses, ceramic products such as sanitary ware, tableware, flower vases, aquariums, sashes, doors, etc. Building materials, metal products such as exterior walls of buildings, films for furniture and covers, decorative plates,
Glass, ceramic, metal, plastic products, typified by plastic products such as panels, and their products have traditionally been required to have water-, oil-, and dirt-repellent properties.

[0003] Conventionally, the only way to prevent stains on glass, ceramic, metal, and plastic products was to make the surfaces as smooth as possible. Additionally, coating with a hydrophilic polymer has been used to prevent fogging on the glass surface, but the effect was only temporary. In addition, for metals, etc., there is a method of coating the surface with a fluororesin or the like. In this case, the fluororesin is coated by applying a thin layer of fluorine enamel and then baking it. In other resin coatings, methods such as applying a paint dissolved or suspended in a solvent and drying the solvent, or curing by baking are used.

0004

[Problems to be Solved by the Invention] However, in the method of coating the fluororesin described above, the surface becomes uneven on the order of tens of microns, so it is difficult to obtain a product with excellent gloss, and it is difficult to obtain a product with excellent gloss. Adhesion was poor and a highly durable product could not be obtained. Furthermore, it was not possible to reduce the thickness of the coat. Additionally, other resin coatings also have the same problem of poor adhesion strength and durability. This is due to the fact that the adhesive force with the substrate is due to physical adsorption.

SUMMARY OF THE INVENTION In order to solve the above-mentioned prior art, it is an object of the present invention to provide a film with excellent gloss and a highly antifouling effect that does not allow dirt to adhere or is easily removed even if it does adhere. do.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the water- and oil-repellent stain-proof coating of the present invention is provided on the surface of a substrate on which irregularities of less than the wavelength of visible light are formed, through at least siloxane bonds. It has a structure in which a chemically adsorbed monomolecular film containing fluorine is formed.

[0007] In the above structure, it is preferable that the substrate (base material) contains any one of glass, ceramic, metal, and plastic.

[0008] The first manufacturing method of the present invention includes the steps of forming irregularities of less than the wavelength of visible light on the surface of the substrate, and forming a chlorosilane group (SiCln X3-n group, n=1,2
, 3, X is a functional group), and the substrate is immersed in a non-aqueous organic solvent in which a chlorosilane surfactant having a fluorocarbon group at one end is dissolved, and chemical adsorption consisting of the surfactant is performed. It includes a step of forming a monomolecular film on the surface of the substrate.

[0009] Next, the second manufacturing method of the present invention includes a step of forming irregularities smaller than the wavelength of visible light on the surface of the substrate, and contacting the substrate with a non-aqueous solvent containing a substance containing a plurality of chlorosilyl groups. , a step of causing the hydroxyl group on the surface of the substrate to react with the chlorosilyl group of the substance containing a plurality of chlorosilyl groups to precipitate the substance on the surface of the substrate, and removing excess remaining on the substrate using a non-aqueous organic solvent. After washing and removing the substance containing a chlorosilyl group, the substance is reacted with water to form a monomolecular film of the substance containing a silanol group on the substrate, and the chlorosilane group (SiCln
A chlorosilane surfactant having a linear fluorocarbon group at one end and having a linear fluorocarbon group on the other end is chemically adsorbed onto the substrate to form a monomolecular adsorption film. The method includes a step of accumulating.

0010

[Operation] According to the configuration of the present invention, a chemically adsorbed monomolecular film containing fluorine is formed at least through siloxane bonds on the surface of the substrate on which irregularities of less than the wavelength of visible light are formed. It is possible to obtain a water- and oil-repellent coating with a high antifouling effect, which does not attract dirt or is easily removed even if it does. In other words, it is an extremely thin chemically adsorbed monomolecular film in which siloxane bonds are chemically bonded to the substrate (substrate) side, and a portion containing fluorine groups exists on the surface layer.
It can have excellent gloss and antifouling effects.

Furthermore, according to the structure of the present invention in which the base material includes glass, ceramic, metal, or plastic, it is possible to provide excellent antifouling effects to articles to which it has been difficult to impart antifouling effects. Can provide antifouling effect.

Next, the operation of the manufacturing method of the present invention will be explained.

[0013] General glass, ceramic and metal products are
Since it is hydrophilic, it contains hydroxyl groups on its surface. Therefore, one end has a chlorosilane group (SiCln X3-n group, n=1,
2, 3, X is a functional group), such as a non-aqueous solvent mixed with a chlorosilane surfactant containing a fluorocarbon group and a chlorosilane group, to remove the hydroxyl groups on the surface of the product. The chlorosilyl groups of the substance containing a plurality of chlorosilyl groups are reacted to deposit a monomolecular film of the substance on the surface of the product, or the product is brought into contact with a non-aqueous solvent containing a mixture of a substance containing a plurality of chlorosilyl groups. A step of reacting the hydroxyl group on the surface with the chlorosilyl group of the substance containing a plurality of chlorosilyl groups to precipitate the substance on the surface of the product, and removing a plurality of excess chlorosilyl groups remaining on the surface of the product using a non-aqueous organic solvent. A step of washing and removing the contained substances, forming a siloxane-based monomolecular film made of a substance containing a plurality of chlorosilyl groups on the substrate surface of the product, and adding a hydrophilic hydroxyl group to the surface; A fluorocarbon-based chemically adsorbed monomolecular cumulative film can be formed on the surface of the product by chemically adsorbing a silane surfactant containing a straight carbon chain onto the surface of the product substrate and accumulating a monomolecular adsorbed film. At this time, by forming irregularities of less than the wavelength of visible light (approximately 400 nm) on the surface of the substrate before the chemical adsorption step, the water and oil repellency of the surface can be significantly improved without impairing the gloss of the product.

[0014] If the material is plastic such as acrylic resin or polycarbonate resin, the same technique can be used by plasma treating the surface to oxidize the surface and make it hydrophilic.

In the case of translucent glass, a water- and oil-repellent antifouling monomolecular film is formed only on the surface, and a monomolecular film with hydrophilic hydroxyl groups is created on the inner surface to provide antifogging properties. Can be granted.

[0016] In the present invention, the substrate surface is preliminarily coated with light having a wavelength of less than the wavelength of visible light (400 nm) (more preferably 0.3 to 400 nm).
By forming unevenness (0.01 micron) on the product surface and covering the product surface with a fluorocarbon monomolecular film with an extremely thin nanometer-level film thickness, the surface becomes water-repellent without impairing the product's original gloss. It becomes possible to enhance the oil antifouling effect. Therefore, a high-performance product with high water-, oil-, and stain-proofing effects can be provided.

[0017]

[Example] Products related to the present invention include glass products such as vehicle window glasses and windshields, optical lenses, eyeglass lenses, and building window glasses, and ceramic products such as sanitary ware, tableware, flower vases, and aquariums. There are also building materials such as sashes and doors, metal products such as exterior walls of buildings, and plastic products such as films for furniture and covers, decorative plates, and plastic panels, but we will take glass plates and aluminum plates as representative examples and explain them in order. . In addition, below, % indicates weight %.

Example 1 First, a processed glass plate was prepared, and after cleaning with an organic solvent, the surface was sandblasted to give a coating of 0.1
Forms unevenness on the order of microns (Figure 1). In addition to this method, a chemical etching method using hydrofluoric acid or a rubbing method using sandpaper can be used as a means for roughening the surface of glass or the like. Further, if the roughness of the unevenness is less than the wavelength level of visible light, substantially all visible light is transmitted, so there is no problem.

Next, a nonaqueous solvent containing a substance containing a fluorocarbon group and a chlorosilane group, such as CF3 (C
Using F2 )7 (CH2 )2 SiCl3, 1
80% n-hexadecane dissolved at a concentration of about % by weight (
toluene, xylene, dicyclohexyl), 1
When a 2% carbon tetrachloride and 8% chloroform solution is prepared and the glass plate is immersed for about 2 hours, a natural oxide film is formed on the surface of the glass plate, and the surface of the oxide film contains many hydroxyl groups. As a result, the SiCl group of the substance containing fluorocarbon groups and chlorosilane groups reacts with the hydroxyl group, and a dehydrochlorination reaction occurs, causing CF3 (C
F2 )7 (CH2 )2 Si(O-)3 bonds were generated, and a monomolecular film 2 containing fluorine was formed with a film thickness of approximately 15 angstroms in a state of chemical bonding with the surface of the glass plate (Figure 2 ). It should be noted that the monomolecular film was not peeled off at all because it was chemically bonded to the base material surface very strongly with siloxane. In addition, if the material of the glass plate is plastic such as acrylic resin or polycarbonate resin, the surface should be plasma treated (300 W, about 10 minutes) to oxidize the surface and make it hydrophilic, and the adsorbent should be treated with Freon solvent. It was possible to use a similar technique by changing to .

[0020] When we tried to use this glass plate in practice, we were able to significantly reduce the adhesion of dirt compared to the untreated glass plate.
Furthermore, even if it did adhere, it could be easily removed by rubbing it with a brush. At this time, there were no scratches at all. In addition, oil and fat stains could be removed only by washing with water. Further, the wettability to water was comparable to that of a lotus leaf, and the wetting angle was about 155 degrees.

Example 2 In the case of an aluminum plate which is hydrophilic but contains a small proportion of hydroxyl groups, the surface is electrolytically etched to form irregularities of about 0.2 microns on the surface. In addition to this method, a chemical etching method using hydrofluoric acid or a rubbing method using sandpaper can be used. Also in this case, if the roughness of the unevenness is less than the wavelength level of visible light, there is no problem because substantially all visible light is transmitted. All metals can be used in the same way, but if the material is plastic such as acrylic resin or polycarbonate resin, the surface can be roughened and then plasma treated at 200 W for about 10 minutes to oxidize the surface and make it hydrophilic. By doing so, it becomes possible to use a similar technique.

Next, a substance containing a plurality of trichlorosilyl groups (for example, SiCl4, SiHCl3, S
iH2Cl2, Cl-(SiCl2O)n-S
iCl3 (n is an integer). In particular, if SiCl4 is used, it has a small molecule and high activity towards hydroxyl groups, so it has a great effect of uniformly making the surface of the aluminum plate hydrophilic. When the aluminum plate is immersed to a certain extent, there are some hydrophilic OH groups 12 on the aluminum plate surface 11 (Fig. 3), so a dehydrochloric acid reaction occurs on the surface and a chlorosilane monomolecular film containing a plurality of trichlorosilyl groups is formed. Ru.

For example, if SiCl4 is used as a substance containing a plurality of trichlorosilyl groups, a small amount of hydrophilic OH groups are exposed on the surface of the aluminum plate 11, so a dehydrochlorination reaction occurs on the surface, and Cl3 SiO- Ya Cl
Molecules are anchored to the surface via -SiO- bonds, such as 2Si(O-)2.

[0024] Then, by washing with a non-aqueous solvent such as chloroform and further washing with water, SiCl4 molecules that have not reacted with the aluminum plate are removed, and (OH)3 SiO- and (OH)2 are formed on the surface of the aluminum plate. Si(O
-) 2 siloxane monomolecular film 13 is obtained (Fig. 4
).

Note that the monomolecular film 13 formed at this time is completely bonded to the aluminum plate through chemical bonds of -SiO-, and therefore does not peel off at all. Further, the obtained monomolecular film has many silanol bonds (SiOH bonds) on the surface. Approximately three times as many hydroxyl groups as the original hydroxyl groups are generated.

Therefore, a non-aqueous solvent containing a substance containing a fluorocarbon group and a chlorosilane group, such as CF
3 (CF2)7 (CH2)2SiCl3 was prepared by preparing a solution of 80% n-hexadecane, 12% carbon tetrachloride, and 8% chloroform dissolved at a concentration of about 1%, and a monomer having many SiOH bonds on the surface was prepared. When the aluminum plate on which the molecular film has been formed is immersed for about an hour, CF3 (CF2)7 (CH2)2 Si(O) is formed on the surface of the aluminum plate.
−) 3 bonds are generated and a monomolecular film 14 containing fluorine
was chemically bonded to the underlying siloxane monomolecular film, and was able to form a film with a thickness of about 15 angstroms over the entire surface of the aluminum plate (Figure 5). Note that the monomolecular film did not peel off at all even when a peel test was performed. Further, the wetting angle with respect to water was 155 degrees.

Furthermore, in the above examples, CF3 (CF2)7 (CH2
)2 SiCl3 was used, but in addition to the above-mentioned fluorocarbon surfactants, CF3 CH2 O(C
H2)15SiCl3, CF3(CH2)2
Si(CH3)2(CH2)15SiCl3,
F(CF2)4(CH2)2Si(CH3)
2 (CH2)9 SiCl3, CF3 COO(
CH2)15SiCl3, CF3(CF2)5
(CH2)2SiCl3 etc. can be used.

In the second embodiment, a glass plate is used instead of an aluminum plate, and when a substance containing a fluorocarbon group and a chlorosilane group is chemically adsorbed, the glass plate remains hydrophilic in order to provide an antifogging effect. By forming an organic solvent-insoluble hydrophilic film (for example, applying an aqueous solution of poval or pullulan to a thickness of several microns) on the surface that you want to leave (for example, the inner surface), the hydrophilic film will be removed after the adsorption is completed. is removed by washing with water, and the surface becomes water-repellent, oil-repellent and stain-resistant monomolecular film 1 as shown in Figure 6.
In step 4, a transparent glass having a monomolecular film (siloxane film) 13 having a hydrophilic hydroxyl group on the inner surface was obtained. The antifogging effect of this glass was confirmed, and the glass surface, which remained hydrophilic, was extremely wettable with water and did not fog at all.

In addition, two types of adsorption reagents with different molecular lengths may be mixed (for example, F(CF2)8(C
H2)2Si(CH3)2(CH2)9S
i(OCH3 )3 , and F(CF2 )8 (CH2
)2 Si(CH3 )2 (CH2 )6 Si(
OCH3 )3 or CF3 (CF2)7
(CH2)2 SiCl3 and CF3 (CF2
)5 (CH2 )2 SiCl3 with a composition of 3:1 to 1:3) If adsorbed, it is possible to make the surface of the component uneven at the molecular level, further improving water and oil repellency. , the antifouling effect becomes even greater.

As explained above, according to this example, irregularities of about 0.1 micron are formed on the surface of a base material such as a glass plate, and then, for example, a fluorine-containing chlorosilane surfactant is diluted in an organic solvent. When the glass plate is immersed in water, a natural oxide film is formed on the surface of the glass plate, and since the oxide film surface contains many hydroxyl groups, a dehydrochloric acid reaction occurs.
A fluorocarbon monomolecular film is formed on the substrate surface via siloxane bonds. As a result, irregularities of less than the wavelength of visible light (400 nm) are formed on the surface of the substrate, and a fluorocarbon monomolecular film with a thickness of nanometer level is formed on the surface of the substrate via siloxane bonds. A film with extremely high water- and oil-repellent and stain-proofing effects can be obtained without impairing gloss.

[0031]

Effects of the Invention As explained above, according to the present invention, an extremely thin fluorocarbon monomolecular film with a film thickness on the nanometer level is formed on the surface of a substrate that has irregularities of less than the wavelength of visible light (400 nm). Therefore, the original gloss of translucent glass is not impaired. In addition, this fluorocarbon monomolecular film has excellent water and oil repellency, making it possible to enhance the water, oil, and stain resistant effects on the surface of the product. Further, by treating the surface of a glass plate with the method of the present invention, it is possible to provide a high-performance translucent glass that is highly water-repellent, oil-repellent, anti-fogging, and anti-fouling.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a glass plate with a roughened surface used in an embodiment of the present invention.

FIG. 2 is a conceptual cross-sectional view of the surface of a glass plate on which a monomolecular film of one embodiment of the present invention is formed, enlarged to the molecular level.

FIG. 3 is a conceptual diagram of a cross-sectional process before treatment, enlarging the surface of an aluminum plate to the molecular level to explain a second embodiment of the present invention.

FIG. 4 A cross-sectional process conceptual diagram of the siloxane-bonded monomolecular film.

[Fig. 5] A cross-sectional process conceptual diagram of the same fluorine-based monomolecular film.

FIG. 6 is an enlarged conceptual cross-sectional view of the surface of a light-transmitting glass plate whose surface is water- and oil-repellent and whose inner surface is antifogging, according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1... Glass plate, 2, 14... Monomolecular film, 12... Hydroxyl group, 13... Siloxane monomolecular film, 15... Water droplet, 16... Water film.

Claims (4)

[Claims] 1. A water- and oil-repellent antifouling coating, comprising a chemically adsorbed monomolecular film containing fluorine via at least siloxane bonds, formed on the surface of a substrate having irregularities smaller than the wavelength of visible light. [Claim 2] The substrate is glass, ceramic, metal,
The water-repellent, oil-repellent and stain-resistant coating according to claim 1, which comprises any one of plastics. 3. A step of forming irregularities of less than the wavelength of visible light on the surface of the substrate, and forming a chlorosilane group (SiCln
X3-n group, n=1,2,3, X is a functional group),
The step includes immersing the substrate in a non-aqueous organic solvent in which a chlorosilane surfactant having a fluorocarbon group at the other end is dissolved to form a chemically adsorbed monomolecular film made of the activator on the surface of the substrate. A method for producing a water-repellent, oil-repellent and stain-resistant film. 4. A step of forming irregularities of less than the wavelength of visible light on the surface of the substrate, and contacting the substrate with a non-aqueous solvent containing a substance containing a plurality of chlorosilyl groups to form hydroxyl groups on the surface of the substrate and the chlorosilyl groups. a step of reacting with a substance containing a plurality of chlorosilyl groups to precipitate the substance on the surface of the substrate, and washing and removing the substance containing excess chlorosilyl groups remaining on the substrate using a non-aqueous organic solvent, A step of forming a monomolecular film made of a substance containing silanol groups on the substrate by reacting with water, and a step of forming a monomolecular film made of a substance containing silanol groups at one end; and a step of chemically adsorbing a chlorosilane surfactant containing a linear fluorocarbon group at one end onto a substrate to accumulate a monomolecular adsorption film. Production method.