JPH04221630A - Translucent substrate and its manufacture - Google Patents

Abstract

PURPOSE:To improve a stainproof effect, water repellancy and oil repellancy without spoiling essential gloss of translucent glass, by forming carbon fluoride monomolecular film on the surface of the translucent glass having an extremely thin film thickness of a nanometer level. CONSTITUTION:A natural oxide film is formed on the surface of front glass and a large number of hydroxyl groups are contained in the oxidized surface. Therefore, one layer of a chemical adsorption monomolecular film 2 is formed on the surface of the front glass 1 through a siloxane bond under a state where dehydrochloric acid reaction between chlorine of a identicalSiCl group of a substance containing a carbon fluoride group and chlorosilane group and the hydroxyl group is performed and the monomolecular film 2 containing fluorine is bonded chemically to the surface of a glass extended over the whole of the surface of the front glass. In this instance, defogging front glass where one side surface has water repellancy, oil repellancey and stainproof monomolecular film and the other surface has the hydrophilic hydroxyl group, is obtained by removing a hydrophilic film by washing the same with water after completion of adsorption by a method wherein an aqueous solution of polyvinyl alcohol is applied and formed onto the surface, which is desirous of leaving as it is hydrophilic, as an organic solvent-resistant and hydrophilic film.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a light-transmitting substrate, and more specifically, it is water-repellent, oil-repellent, stain-resistant, and used in vehicle or building windows, vehicle windshields, optical lenses, eyeglass lenses, etc. This invention relates to a translucent substrate that requires good effects.

0002

[Prior Art] Conventionally, in order to prevent stains on a transparent substrate such as glass, methods have been proposed to make the surface as smooth as possible, or to coat the surface with a protective film such as a fluorine-based film. ing. Further, in order to prevent the surface of a transparent substrate from becoming cloudy, a method of coating a hydrophilic polymer or a method of installing a heater in or on the surface of a transparent substrate is used.

0003

[Problems to be Solved by the Invention] If the stain on the transparent substrate is caused by water droplets, the anti-fogging effect will work, for example, by installing a heater. However, a power source for the heater is required, and there is a problem that the heater, which is buried or installed on the surface, interferes with the uniform brightness of the transparent substrate. In addition, for example, the method of applying a hydrophilic polymer is relatively simple, but
The effect is temporary, and there is a problem that the hydrophilic polymer easily peels off when the surface of the transparent substrate is rubbed.

[0004] These methods are almost meaningless when the cause of contamination is other than water droplets, and a method has been proposed in which a fluorine-based protective film is applied to the surface of a translucent substrate. The adhesion between the chemical substrate and the fluorine-based protective film is weak and easily peels off.
In addition, the opacity of the fluorine-based protective film itself causes the transparent substrate to become cloudy, and while other protective film materials improve transparency and adhesion, there is the problem that dirt components cannot be easily wiped off. . Therefore, it is practical to make the surface of a translucent substrate as smooth as possible, but there is a limit to how smooth it can be, and in the end, a translucent substrate that has been actively treated to prevent stains or be water and oil repellent is The problem was that there was no.

[0005] An object of the present invention is to provide a light-transmitting substrate with high water repellency and antifouling effect so that dirt does not adhere thereto, or even if it does, it is easily removed.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention proposes a light-transmitting substrate in which a chemically adsorbed monomolecular film containing water-repellent groups is formed on at least one surface.

[0007]

[Operation] In the light-transmitting substrate of the present invention, the chemically adsorbed monomolecular film formed on the surface of the substrate is extremely thin with a film thickness on the nanometer level, so that the inherent light-transmitting properties of the substrate are not impaired. Moreover, since the chemically adsorbed monomolecular film of the present invention has water repellency, it is possible to enhance the antifouling effect on the surface. Furthermore, if a chemically adsorbed monomolecular film containing water-repellent groups is formed on one surface of a transparent substrate and a chemically adsorbed monomolecular film containing hydrophilic groups is formed on the other surface of the transparent substrate, one A translucent substrate can be provided that has a water-repellent and antifouling effect on one side and an antifogging effect on the other side.

[0008]

EXAMPLE Glass or plastic is used as a general light-transmitting substrate material. When the substrate material is glass, the surface contains a hydrophilic group such as a hydroxyl group, and even if the substrate material is a plastic material, the surface can be made hydrophilic by simple oxidation treatment. Therefore, when a non-aqueous organic solvent in which a molecule containing a carbon chain with a reactive silane group at one end is dissolved, the active hydrogen of the hydrophilic group on the surface reacts with the reactive silane group, and the reaction occurs through silicon-containing chemical bonds. to form a monolayer. This kind of reaction is called a chemisorption reaction, and the monomolecular film obtained in this way is called a chemisorption monomolecular film, because a chemisorption monomolecular film has a strong chemical bond with the real image side surface of the mirror. Generally, the adhesion strength is such that it does not peel off unless the surface of the light-transmitting substrate is scraped off. When a water-repellent group is included at the other end of this molecule, this water-repellent property brings out the stain-preventing effect.

The light-transmitting substrate material of the present invention may include glass as described above, as well as plastics such as acrylic resin and carbonate resin, but glass is the most common and exclusively used. Hydrophilic groups must be exposed on the surface of the light-transmitting substrate of the present invention, and examples of the hydrophilic groups include groups having active hydrogen such as hydroxyl groups, carbonyl groups, and amino groups. When there are few hydrophilic groups on the surface of the light-transmitting substrate material, it is made hydrophilic by a conventional method such as electron beam irradiation or ion beam irradiation in an oxygen or nitrogen atmosphere.

The constituent molecules of the chemically adsorbed monomolecular film used in the present invention include chlorosilane (-SiClnX3) at one end.
-n) group or alkoxysilane (-Si(OA)nX3
-n) group, and a silane surfactant containing a hydrocarbon group or fluorine-substituted carbon at the other end. However, n in the formula is an integer of 1 to 3, X represents hydrogen, a lower alkyl group or a lower alkoxy group, and A represents a lower alkyl group. Among the silane-based surfactants mentioned above, chlorosilane-based surfactants are preferable because they can carry out a chemisorption reaction at room temperature and can reliably form a chemisorption monomolecular film. Among the chlorosilane surfactants, a trichlorosilane group (that is, n in the formula is 3) is preferable because siloxane bonds are formed between adsorbed molecules. Furthermore, the silane surfactant used in the present invention is preferably linear in order to improve the density of adsorbed molecules. Specifically, CH3-(R)m-SiClnX
3-n, CF3-(CF2)p-(R)m-SiCln
A chlorosilane surfactant represented by X3-n is preferred. However, in the formula, p is 0 or an integer, m is 0 or 1, R
is a methylene group with a carbon number of 1 or more, a vinylene-containing group with a carbon number of 1
Any of the above methylene groups, ethynylene-containing methylene groups having 1 or more carbon atoms, silicon-containing methylene groups having 1 or more carbon atoms, or oxygen-containing atoms having 1 or more carbon atoms, X is a hydrogen atom, lower an alkyl group or a lower alkoxy group, n is an integer of 0 to 2; More specifically, for example, C
H3(CH2)9SiCl3, CH3(CH2)15S
iCl3, CH3CH2O(CH2)15SiCl3,
CH3(CH2)2Si(CH3)2(CH2)15S
iCl3, CF3(CF2)7(CH2)2SiCl3
, CF3CH2O(CH2)15SiCl3, CF3(
CH2)2Si(CH3)2(CH2)15SiCl3
, F(CF2)4(CH2)2Si(CH3)2(CH
2) 9SiCl3, CF3COO(CH2)15SiC
13, CF3(CF2)5(CH2)2SiCl3, and the like. In addition, when the R group in the above formula contains a vinylene group or an ethynylene group, the unsaturated bonds are polymerized by a catalyst, light, or high-energy ray irradiation, resulting in intermolecular bonds, resulting in a stronger monomolecular film. Therefore, it is preferable. Note that it is particularly preferable to use a fluorinated carbon as the water-repellent group because it has a large water-repellent effect and can also exhibit an oil-repellent effect.

[0011] The method for manufacturing the translucent substrate of the present invention includes:
A preformed translucent substrate is generally provided. In addition, especially when using a chlorosilane surfactant in the light-transmitting substrate of the present invention, it is generally not necessary to wash the chemisorption monomolecular film without contacting it with moisture after forming the chemisorption monomolecular film. If this washing step is not performed, unreacted chlorosilane surfactant reacts with moisture and becomes cloudy.

In addition, especially when using a chlorosilane surfactant in the present invention, it is necessary to dissolve it in a non-aqueous organic solvent because the surfactant has high reactivity with water. For example, n-hexadecane, toluene, xylene, dicyclohexyl, carbon tetrachloride, chloroform, etc. may be used alone or in combination. In the case of silane-based surfactants other than chlorosilane-based,
In addition to these, for example, methyl alcohol, ethyl alcohol, etc. can also be used.

Furthermore, the chemically adsorbed monomolecular film of the present invention can be obtained by contacting one surface of a light-transmitting substrate with a substance containing a chlorosilyl group, and then washing the unreacted substance containing a chlorosilyl group and reacting it with water. By forming a monomolecular film having silole groups on the surface of a transparent substrate and then chemically adsorbing a silane surfactant containing fluorocarbon,
Even in the case of a mirror with few hydrophilic groups exposed on the surface, it is preferable because the silane surfactant containing the water-repellent group can be chemically adsorbed at high density. Examples of materials having this chlorosilyl group include SiCl4, SiHCl3, Si
H2Cl2, Cl-(SiCl2O)n-SiCl3,
Hl(R1)3-lSi(R2)nSiClm(R3)
3-m and the like, and in general, it is preferable that the number of Cl--Si bonds is large because the silane surfactant can be chemically adsorbed at a high density. However, in the formula, n is an integer, l and m are integers of 1 to 3, R1 and R3 are lower alkyl groups, and R2 is a methylene group having 1 or more carbon atoms. In particular, it is preferable to use SiCl4 as the substance containing a chlorosilyl group, since the molecule is small and the activity against hydroxylization is large, so that the effect of uniformly making the mirror surface hydrophilic is large. Furthermore, the light-transmitting substrate of the present invention has a chemically adsorbed monomolecular film containing a water-repellent group formed on only one surface, and a chemically adsorbed monomolecular film containing a hydrophilic group on the other surface. It is also possible to provide a substrate that exhibits different properties on both sides of the substrate. For example, this method involves chemically adsorbing a substance containing chlorosilane groups onto both sides of a transparent substrate to form a monomolecular film containing chlorosilane groups, and washing this monomolecular film with water to precipitate silole groups on the surface. Then, apply an aqueous solution of a water-soluble polymer material such as polyvinyl alcohol or pullulan to the surface to be left with a hydrophilic monolayer, and then form a chemically adsorbed monolayer containing water-repellent groups. However, there is a method in which the water-soluble polymer material is then removed by washing with water.

[0014] The chemically adsorbed monomolecular film of the present invention may be a single layer monomolecular film or a monomolecular cumulative film, but in the case of a monomolecular cumulative film, it is required that there be chemical bonds between the cumulative layers. be done.

[0015] Glass will be cited as a translucent substrate material relating to the present invention, and an automobile windshield will be taken up as a representative example and explained in order.

Example 1 First, after cleaning the processed windshield with an organic solvent, it was washed with a non-aqueous solvent using CF3(CF2)7(CH2)2SiCl3 as a substance containing fluorocarbon groups and chlorosilane groups. 80% n-hexadecane, 12%
A solution was prepared by dissolving carbon tetrachloride and 8% chloroform in a mixed solvent at a concentration of 10%, and the windshield was immersed for about 2 hours. A natural oxide film is formed on the surface of the windshield, and the surface of the oxide film contains many hydroxyl groups. Therefore, the chlorine of the ≡SiCl group of substances containing fluorocarbon groups and chlorosilane groups and the hydroxyl groups are removed. Hydrochloric acid reacts and the bond shown in (Chemical formula 1) is generated over the entire surface of the windshield.

[0017]

[Chemical 1] With the fluorine-containing monomolecular film 2 chemically bonded to the surface of the mirror, a chemisorbed monomolecular film 2 was formed on the surface of the windshield 1 through siloxane bonds as shown in FIG. . The thickness of this chemically adsorbed monomolecular film 2 is approximately 15 Å from the molecular structure. Note that the monomolecular film had extremely strong chemical bonds, so it did not peel off at all.

[0018] When we tried to use this windshield in practice, we were able to significantly reduce the adhesion of dirt compared to the untreated one, and even if it did stick, it could be easily removed by rubbing it with a brush or the like. Further, at this time, no scratches were left on the surface of the windshield 1. In addition, oil and fat stains could be removed only by washing with water.

Note that if the material of the transparent substrate is plastic such as acrylic resin or polycarbonate resin,
It was possible to use a similar technique by oxidizing the surface to make it hydrophilic by subjecting the surface to plasma treatment at 300 W for 10 minutes, for example, and by replacing the adsorption liquid with a Freon solvent.

Example 2 In the case of a windshield that is hydrophilic but contains a small proportion of hydroxyl groups, for example, the surface of which is crosslinked with a crosslinkable plastic, Si is used as a material containing trichlorosilyl groups.
When Cl4 is immersed in a solution of 1% by weight dissolved in chloroform, a non-aqueous solvent, for about 30 minutes, some hydrophilic hydroxyl groups (OH groups) 12 are present on the surface of the windshield 11, as shown in FIG. Therefore, a dehydrochlorination reaction occurred on the surface, and a chlorosilane monomolecular film of a substance containing trichlorosilyl groups was formed. If SiCl4 is used as a substance containing a trichlorosilyl group in this way, even if only a small amount of hydrophilic OH groups 12 are present on the surface of the windshield 11, the dehydrochlorination reaction will occur on the surface of the windshield 11 (Chemical formula 2). As such, molecules are immobilized on the surface via -SiO- bonds.

[0021]

[Chemical formula 2] At this time, unreacted SiCl4 is also present on the chlorosilane monomolecular film, so if it is then washed with a non-aqueous solvent such as chloroform and then with water, the hydroxyl groups on the surface of the windshield 11 are removed. The unreacted SiCl4 molecules are removed, and a siloxane monomolecular film 13 such as (Chemical formula 3) is obtained on the surface of the windshield 11 as shown in FIG.

[0022]

[Image Omitted] Note that the monomolecular film 13 formed at this time is completely bonded to the surface of the windshield 11 through the chemical bonds of -SiO-, and therefore will not peel off at all. Moreover, the obtained siloxane monomolecular film 13 has many SiOH bonds on the surface. Approximately three times as many hydroxyl groups as the original hydroxyl groups are generated.

Next, when the windshield 11 with the siloxane monomolecular film 13 formed on its surface is immersed in the solution described in Example 1 for about one hour, the siloxane monomolecular film 13 is immersed in the solution described in Example 1.
A bond of (Chemical formula 4) is generated on the surface, and as shown in FIG. 4, the chemically adsorbed monomolecular film 14 containing fluorine is chemically bonded to the siloxane monomolecular film 13 below, and a bond of approximately 15 Å is formed over the entire surface of the mirror. It was possible to form a film with a film thickness of .

[0024]

[Image Omitted] Note that the monomolecular film did not peel off at all even when a peel test was performed.

[0025]Also, actual use was attempted using the windshield of this example, but due to the water-repellent effect of the fluorine on the surface, there was no adhesion of water droplets at all. I sprayed acetone on it, but the oil was repelled by the oil-repellent effect of the fluorine in the monomolecular film that was chemically adsorbed on the surface, so it did not become cloudy, and the dirt was easily wiped off.

[0026] When chemically adsorbing a monomolecular film using a non-aqueous solvent containing a substance containing a fluorocarbon group and a chlorosilane group, the surface to be left hydrophilic has an antifogging effect. By applying and forming an aqueous polyvinyl alcohol solution as a hydrophilic film that is resistant to organic solvents, the hydrophilic film can be washed away after adsorption and one surface becomes water repellent as shown in Figure 5. A windshield was obtained in which the oil-repellent and antifouling monomolecular film 14 had a monomolecular film 13 having hydrophilic hydroxyl groups on the other side. The antifogging effect of this glass was confirmed, and the glass surface, which remained hydrophilic, did not fog at all.

In addition, in Example 1, in the case of a single layer of monomolecular film,
In Example 2, a case was shown in which a single layer of a siloxane monolayer was followed by a layer of a silane-based surfactant containing fluorine. The effect is not variable.

Furthermore, in the above example, CF3(CF2)7 was used as the fluorocarbon chlorosilane surfactant.
(CH2)2SiCl3 was used, but CF3-(CF2
)p-(R)m-SiClnX3-n, for example, a vinylene group (
If -CH=CH-) or ethynylene group (-C≡C-) is added or incorporated, it can be crosslinked by electron beam irradiation of about 5 megarads after monomolecular film formation, further improving the hardness of the monomolecular film. It is also possible to do so.

In addition to the above-mentioned fluorocarbon surfactants, CF3CH2O(CH2)15SiCl
3, CF3(CH2)2Si(CH3)2(CH2)1
5SiCl3, F(CF2)4(CH2)2Si(CH
3) 2(CH2)9SiCl3, CF3COO(CH2
)15SiCl3, CF3(CF2)5(CH2)2S
Trichlorosilane surfactants such as iCl3, for example CF3CH2O(CH2)15Si(CH3)2C
l, CF3(CH2)2Si(CH3)2(CH2)1
5Si(CH3)2Cl, CF3CH2O(CH2)1
5Si(CH3)Cl2, CF3COO(CH2)15
Chlorosilane surfactants such as Si(CH3)2Cl were available. Also, CF3(CF2)7(CH2)2Si(
OCH3)3, CF3CH2O(CH2)15Si(O
Similar effects were obtained using alkoxysilane surfactants such as CH3)3 by heating the surfactant solution. CH3(CH2)9SiCl3, CH3(CH2)1
5SiCl3, CH3CH2O(CH2)15SiCl
3, CH3(CH2)2Si(CH3)2(CH2)1
Chlorosilane surfactants having a hydrocarbon group such as 5SiCl3 also formed a chemically adsorbed monomolecular film at room temperature, exhibiting water repellency and antifouling properties.

[0030]

[Effects of the Invention] As described above, since an extremely thin fluorocarbon monomolecular film with a film thickness on the nanometer level is formed on the surface of a light-transmitting glass, the inherent luster of the light-transmitting glass is not impaired. Furthermore, this fluorocarbon monomolecular film has excellent water and oil repellency, making it possible to enhance the antifouling effect on the surface. Therefore, it is possible to provide a high-performance light-transmitting glass with an extremely high antifouling effect. Furthermore, by making the inner surface hydrophilic, an antifogging effect was also obtained.

[Brief explanation of the drawing]

[Fig. 1] A conceptual cross-sectional diagram of a windshield, which is an example of the translucent substrate of the present invention, enlarged to the molecular level.

[Fig. 2] A cross-sectional process conceptual diagram showing the surface of a windshield, which is another example of the light-transmitting substrate of the present invention, enlarged to the molecular level.

[Fig. 3] A cross-sectional process conceptual diagram showing the surface of a windshield, which is another example of the light-transmitting substrate of the present invention, enlarged to the molecular level.

[Fig. 4] A cross-sectional process conceptual diagram showing the surface of a windshield, which is another example of the transparent substrate of the present invention, enlarged to the molecular level.

[Fig. 5] A conceptual cross-sectional view of the surface of a windshield, which is another example of the transparent substrate of the present invention, enlarged to the molecular level.

[Explanation of symbols]

1. Windshield 2　Chemisorption monolayer 11 Windshield 12 Hydroxyl group 13 Siloxane monolayer 14 Chemical adsorption monolayer

Claims (12)

[Claims] [Claim 1] A chemically adsorbed monomolecular film containing a water-repellent group,
A translucent substrate characterized by being formed on at least one surface. [Claim 2] A chemically adsorbed monomolecular film containing a water-repellent group,
2. The light-transmitting substrate according to claim 1, wherein the transparent substrate has a siloxane bond. [Claim 3] A chemically adsorbed monomolecular film containing a water-repellent group,
3. The light-transmitting substrate according to claim 2, wherein the transparent substrate is formed on the surface with at least a siloxane-based monomolecular film interposed therebetween. 4. A transparent material characterized by having a chemically adsorbed monomolecular film containing water-repellent groups formed on its surface on one side, and covered with a chemically adsorbed monomolecular film containing hydrophilic groups on the other side. Photosensitive substrate. 5. The light-transmitting substrate according to claim 1, wherein the water-repellent group is a fluorine-containing hydrocarbon group. 6. The light-transmitting substrate according to claim 4, wherein the hydrophilic group is a hydroxyl group. 7. At least one surface of the transparent substrate that has been molded is coated with an organic solvent containing a silane surfactant having a reactive silane group at one end and a water-repellent group at the other end. A method for producing a light-transmitting substrate, comprising the step of contacting the light-transmitting substrate to form a chemically adsorbed monomolecular film made of the silane surfactant over the entire surface of the light-transmitting substrate. 8. A contacting step in which at least one surface of the transparent substrate that has been molded is brought into contact with a non-aqueous solvent mixed with a substance containing a chlorosilyl group; A cleaning step in which a substance containing a reactive chlorosilyl group is washed away using a non-aqueous organic solvent, and a silole formation step in which a monomolecular film made of a substance containing a silole group is formed on the transparent substrate by reacting with moisture after the washing step. process,
After the silole formation step, a chemical method in which a silane surfactant having a reactive silane group at one end and a water-repellent group at the other end is used to accumulate a chemically adsorbed monomolecular adsorption film on the monomolecular film containing the silole group. A method for producing a translucent substrate, comprising a step of accumulating an adsorbed monolayer. 9. Claim 8, further comprising a coating step of coating one surface of the light-transmitting substrate with a water-soluble film between the silole forming step and the chemically adsorbed monomolecular film accumulation step. The method for manufacturing the translucent substrate described above. 10. The method for producing a light-transmitting substrate according to claim 7, wherein the reactive silane group is a chlorosilane group. Claim 11: The silane surfactant is CF3-(
CF2) n-(R)m-SiClpX3-p (n is 0 or an integer, m is 0 or 1, R is a methylene group having 1 or more carbon atoms, a methylene group having 1 or more carbon atoms in a vinylene-containing group, an ethynylene-containing group a methylene group with 1 or more carbon atoms, a methylene group with 1 or more carbon atoms of a silicon-containing atom, or a methylene group with 1 or more carbon atoms of an oxygen-containing atom, X is a hydrogen atom, a lower alkyl group, or a lower alkoxy group, p is an integer from 0 to 2)
The method for producing a translucent substrate according to claim 7 or 8, characterized in that: 12. The substance containing a chlorosilyl group is Si
Cl4, SiHCl3, SiH2Cl2, Cl-(Si
9. The method for producing a translucent substrate according to claim 8, wherein the substrate is one of Cl2O)n-SiCl3 (n is an integer).