JP2002088298A - Hydrophilic coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material excellent in persistence on a surface and hydrophilicity. SOLUTION: The hydrophilic coating material contains a water-soluble cationic polymer, a polyvinyl pyrrolidone, a polyvinyl alcohol, and a nonionic surfactant as the essential constituents.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for damping water droplets adhering to the surface of a fender mirror, a side mirror, a side window, a bathroom, a mirror of a bathroom or the like, a glass of a house or a store or a mirror in a rainfall or the like. The present invention relates to a hydrophilic coating agent that prevents a decrease in visibility by setting a state of (1).

[0002]

2. Description of the Related Art Water droplets adhering to fender mirrors, side mirrors, and side windows of a vehicle during rainfall obstruct the view of the vehicle. I do. As a method of preventing this, a surfactant or a water-soluble polymer is applied to the fender mirror, the side mirror, and the side window to have a hydrophilic action, or conversely, a water repellent such as silicone is applied to apply a repellent. Methods have been taken to provide water action to prevent the attachment of water droplets. However, a surfactant has a problem that it is easily desorbed due to its water solubility and it is difficult to maintain hydrophilicity for a long period of time, and a water repellent cannot prevent the attachment of fine water droplets.

SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the conventional surfactants and water-soluble polymers,
The purpose is to solve the disappearance of the hydrophilic action in a short time.

Means for Solving the Problems In order to achieve the above object, first, it was sought to find out why the conventional hydrophilic agent cannot maintain the hydrophilicity for a long time. It has been found that water-soluble polymers such as surfactants and polyvinyl alcohol, which have been used as conventional hydrophilizing agents, are weakly adsorbed on mirrors and glass, are easily dissolved in water, are water-soluble, and run down. It was found to be the cause of inhibiting long-term hydrophilicity. It is known that polar groups such as hydroxyl groups are unevenly distributed on the surface of mirrors and glass, and it is thought that polar surfactants or water-soluble polymers are suitable for adsorption on these surfaces. Can be Therefore,
After examining these surfactants and water-soluble polymers, by blending cationized water-soluble polymers with polyvinylpyrrolidone or polyvinyl alcohol and nonionic surfactants as essential components, immediately after application to the glass or mirror surface It has been found that instantaneous and long lasting hydrophilization can be achieved. The cationized water-soluble polymer has good adsorptivity to the glass surface and enables long-term hydrophilization. However, this type of cationized water-soluble polymer can cause distortion of the image immediately after application and drying of the substrate. There was a problem that the hydrophilicity of the later coating was reduced. Therefore, immediately after the application, water droplets were promptly removed, and a surfactant was combined to uniformly apply the coating agent to the surface. Surfactants reduce the surface tension of water droplets adhering to the surface, quickly form a water film, remove the water droplets, and help the coating agent to be uniformly applied by its leveling effect. As the surfactant used here, a nonionic surfactant is particularly preferable. Nonionic surfactants have better defoaming properties and better leveling properties than other surfactants,
In particular, Pluronic surfactants are preferred. However, although the distortion of the image immediately after coating could be solved by the addition of the surfactant, it was not possible to prevent the decrease in hydrophilicity after the substrate was dried. Then, polyvinylpyrrolidone or vinyl acetate-vinylpyrrolidone copolymer known as a water-soluble polymer having high hydrophilicity was added. Polyvinylpyrrolidone or vinyl acetate-vinylpyrrolidone copolymer forms a strong film and shows high hydrophilicity even after the film is dried, but has a drawback of poor film-forming properties. Therefore, even when polyvinylpyrrolidone or vinyl acetate-vinylpyrrolidone copolymer is applied alone to a glass surface, it flows down without exhibiting a hydrophilic effect before forming a film. By combining with a cationized water-soluble polymer having excellent adsorptivity to the glass surface in the present invention, polyvinylpyrrolidone is prevented from flowing down from the glass surface before film formation, and a high hydrophilic effect of polyvinylpyrrolidone can be obtained. Was. That is, the present invention relates to starch, guar gum, polyacrylamide, polyacrylic acid ester, vinylformamide, cationized starch obtained by adding 2,3-epoxypropyltrimethylammonium chloride or alkylamine to polyamine, or cationized guar gum or cationized polyamine. Acrylamide or cationized polyacrylate or cationized vinylformamide or cationized polyamine combined with polyvinyl alcohol or vinyl acetate-vinyl alcohol copolymer, polyvinylpyrrolidone, vinyl acetate-vinylpyrrolidone copolymer, pluronic surfactant As a result, water drops adhering to the fender mirrors, side mirrors, and side windows of the car during rainfall are instantaneously wet to ensure good visibility, A hydrophilic coating agent characterized in that it retains hydrophilicity for a long period of time. These cationized water-soluble polymers are 0.05 to 10% by weight, polyvinyl alcohol or polyvinyl pyrrolidone 0.01 to
A hydrophilic coating agent characterized by containing 5% by weight and 0.01 to 2% by weight of a pluronic surfactant.

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the cationized water-soluble polymer used in the present invention include cationized starch such as Hymo Corporation, Himax NC-10, PC-6500,
For cationized guar gum, Sansei Corporation Maypro Bond 9
806, as cationized acrylamide, Arakawa Chemical Industries Co., Ltd. Polymalon 351 and 360, polystron 311 and 619, Alafix 251; as cationized polyacrylic acid ester, Hymo Co., Ltd. Hymoloc MP-284, MP-384 , MP-984, E-
315, E-195, and cationized vinylformamide include Hymoloc ZP-700, and cationized polyamines include Hymoloc Q-311 and Q-501. The cationized water-soluble polymer in the present invention may be present in the present invention in an amount of 0.05 to 10% by weight, preferably 0.1 to 5% by weight. If the amount is less than 0.05% by weight, the fixing property to glass is poor and the durability is poor. . If it exceeds 10% by weight, there is no problem in the fixing property and the sustainability, but the viscosity is increased, so that it is difficult to apply the composition by spraying or the like. Examples of polyvinyl alcohol include Poval C-05GP, C of Shin-Etsu Chemical Co., Ltd.
-10GP, C-25GP, PA-10GP, PA-1
5GP, Kuraray's PVA-217, PVA-22
4 and the like. As polyvinylpyrrolidone, B
ASF Kollidon 12PF, 17PF, 25, 3
0, 90F, VA64 and the like. The polyvinyl alcohol or polyvinylpyrrolidone in the present invention may be present in the present invention in an amount of from 0.01 to 5% by weight, preferably from 0.05 to 3% by weight. In this case, the surface of the liquid film at the time of coating is distorted, and the visibility is unfavorably deteriorated. As the ethylene oxide / propylene oxide block polymer type surfactants, Adeka Pluronic L-44, L-62, L-72, P-84, P-
85 、 Daiichi Kogyo Seiyaku Co., Ltd. Epan 410, 420, 7
10, 720, 740 and the like. The ethylene oxide / propylene oxide block polymer type surfactant in the present invention may be present in the present invention in an amount of 0.01 to 2% by weight, preferably 0.02 to 1% by weight. The surface is distorted, and the visibility is deteriorated. If the content exceeds 2% by weight, there is a problem in sustainability, which is not preferable. Further, in order to increase the degree of cationization of the cationized water-soluble polymer, an organic acid such as formic acid, acetic acid, bromic acid, citric acid or phosphoric acid or a cationizing agent such as epichlorohydrin may be added. The hydrophilizing coating agent of the present invention can be obtained by stirring and dissolving a cationized water-soluble polymer, polyvinyl alcohol or polyvinylpyrrolidone, and a surfactant in water. The hydrophilic coating agent of the present invention has a certain degree of self-cleaning action due to its hydrophilic property against carbon-based dirt due to automobile exhaust gas and dirt caused by splashing of window washer liquid, etc. There is no resistance to dirt that exceeds the capacity and dirt that adheres firmly. Therefore, an attempt was made to add a photocatalyst. The photocatalyst has a photocatalytic action as an optical semiconductor. When the photocatalyst is given energy equal to or greater than its band gap energy, for example, when irradiated with ultraviolet light in the outside, it generates active radicals such as hydroxyl radicals and superoxide ions. Since the active oxygen species has an action of oxidatively decomposing organic substances, it is possible to decompose and remove the above-mentioned dirt. In addition, since the surface also has a phenomenon that the surface becomes highly hydrophilic, the hydrophilic action can be used. As a photocatalyst, titanium oxide, zinc oxide, tin oxide,
Metal oxides such as iron oxide, zirconium oxide, tungsten oxide, chromium oxide, and molybdenum oxide can be used,
Practically, titanium oxide is preferred. The titanium oxide used here has a high photocatalytic activity when the crystal type is anatase type, and many titanium oxide sols are on the market.
It is cheap and can be obtained stably. Therefore, the form of the photocatalyst to be added is an anatase type titanium oxide sol. Further, the average particle size of the titanium oxide is preferably 10 nm or less. Although a substance having a large particle size is said to have a high photocatalytic action, its solution lacks transparency and its appearance may be significantly deteriorated when applied to a mirror, window glass, or the like. Further, the titanium oxide sol is preferably of an aqueous dispersion type. The mixing ratio of the titanium oxide sol is preferably 5% or less, preferably in terms of solids, based on the total weight of the solution.
More preferably, it is 1% or less. In the present invention, a water-soluble organic solvent can be added for the purpose of improving wettability when applied by spraying or the like. As the water-soluble organic solvent, methyl alcohol, ethyl alcohol, isopropyl alcohol, ethylene glycol, glycerin and the like can be used, and among them, ethyl alcohol is preferable. Also,
The mixing ratio is 30% by weight or less, more preferably 10% by weight or less, based on the total weight of the solution. Further, in the present invention, an antioxidant, a preservative, a rust preventive, a wetting agent, and the like may be appropriately blended as long as the performance of the present invention is not hindered.

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. Polymalon 3 while stirring in 99.80 wt% of ion-exchanged water
51 0.20 wt% is added and dissolved to obtain a transparent liquid. Polymalon 3 with stirring in 99.68 wt% of ion exchange water
51 0.20 wt%, PVA-224 0.10 wt%, and epan 420 0.02 wt% are added and dissolved to obtain a transparent liquid. While stirring in 99.68 wt% of ion-exchanged water, Himax PC-6500 0.20 wt%, Poval C-25GP 0.2% by weight.
10 wt% and 0.02 wt% of Adecapluronic P-84 are added and dissolved to obtain a transparent liquid. High Max MP-284 0.20wt%, Kollidon 30 0.10wt while stirring in ion exchange water 99.68wt%
%, And 0.02 wt% of epan 720 are added and dissolved to obtain a transparent liquid. Hymax PC-6500 0.20 wt%, Kollidon 12PF 0.10 while stirring in 99.68 wt% of ion exchange water
wt% and 0.02 wt% of Adecapluronic P-84 are added and dissolved to obtain a transparent liquid. Mayprobond 9806 0.200 wt% while stirring in 99.675 wt% of ion exchange water, Kollidon VA64 0.100
wt%, epan 420 0.020wt%, acetic acid 0.005wt
% And dissolved to obtain a transparent liquid. Mappro CAA M-175 is the uncationized guar gum of Mayprobond 9806 used in Example 6 and used here for comparison. 99.80wt% ion exchange water
While mixing with CAA M-175 0.200wt%
To obtain a transparent liquid. Maproa CAA M-175 0.200wt%, Kollidon 12PF 0.100w while stirring in 99.675wt% of ion exchange water
t%, epan 420 0.020wt%, acetic acid 0.005wt%
To obtain a transparent liquid. (Test method) As a test method, a glass plate (7X15c
After the surface of m) was washed using a cleaner, 2 g of the prepared composition was applied by a spray coating method, and evaluated by the following test methods (1) and (2). (1) Immediately spray the applied glass plate with a household sprayer.
Water was sprayed continuously (total amount: 10 to 12 g). A total of 10 cycles were carried out with this continuous 10 water injections as one cycle. (2) After drying the applied glass plate in a 50 ° C. constant temperature bath for 1 hour, ten times with household spray (total amount: 10 to 12 g).
Water was sprayed continuously. A total of 10 cycles were carried out with this continuous 10 water injections as one cycle.

[Table 1]

According to the present invention, the use of a hydrophilic coating agent containing a cationized water-soluble polymer, polyvinylpyrrolidone or vinyl acetate-vinylpyrrolidone, and a pluronic surfactant makes it possible to coat a mirror or glass. Adhesiveness can be increased, and the drop in visibility caused by water droplets adhering to the surface of fender mirrors, side mirrors, side windows, etc. of automobiles during rainfall can be instantaneously extended for a long time by making the water droplets wet Can be prevented.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Fukushima 2-1-1 Nakajima, Kokurakita-ku, Kitakyushu-shi, Fukuoka Touchi Kiki Co., Ltd. (72) Kunio Arimoto Nishiyanagihara-cho, Hyogo-ku, Kobe-shi, Hyogo 5-26 (72) Inventor Masahiro Eikawa 5-26 Nishiyanagihara-cho, Hyogo-ku, Kobe-shi, Hyogo F-term (reference) 4G059 AA01 AC21 FA07 FA28 FA29 FB06 4G069 BA04B BA05B BA48A BC22B BC35B BC58B BC59B BC60B BC66B EA08 AFB014 AA03 AA05 AA07 AB06 4J038 BA011 BA121 CE021 CF021 CG141 CG171 CK031 CR071 DA131 DF012 HA216 HA416 JA37 KA04 KA09 KA14 MA08 NA06 PA18 PA19 PB02 PB07 PC03

Claims (4)

[Claims] 1. One or two or more water-soluble polymers selected from cationized water-soluble polymers, 0.01 to 10 parts by weight, polyvinyl alcohol, vinyl acetate-vinyl alcohol copolymer, polyvinyl pyrrolidone, acetic acid Vinyl-
0.01 to 5 parts by weight of one or more water-soluble polymers selected from vinylpyrrolidone copolymer and 0.01 to 2 parts by weight of a nonionic surfactant as essential components. Characteristic hydrophilic coating agent. 2. The cationized water-soluble polymer is cationized starch, cationized guar gum, cationized polyacrylamide, cationized polyacrylic acid ester, cationized vinylformamide, or cationized polyamine. The hydrophilic coating agent according to the above. 3. The hydrophilic coating agent according to claim 1, wherein the nonionic surfactant is one or two or more surfactants selected from Pluronic surfactants. 4. The hydrophilic coating agent according to claim 1, wherein a photocatalytic coating composition is added to the hydrophilic coating agent.