JPS6160111B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an anti-fogging agent for glass, and more particularly to an anti-fogging agent for glass that is applied to the surface of glass to provide a long-lasting and good anti-fogging effect and does not impede the transparency of the glass surface. Several methods have been known to prevent fogging of vehicle window glass, but the simplest and most effective method is to create a film of a substance that lowers surface tension, such as a surfactant, on the glass surface. The transparency of the glass surface is often maintained by reducing the contact angle of fine water droplets that form dew to zero. As is well known, the important properties of the anti-fogging agent produced by the above method are that it has the durability of a film that firmly adheres to the glass surface and maintains a good anti-fogging effect for a long time; The coating itself that provides the anti-fogging effect does not crystallize and always remains transparent. Many compounds have been tried and proposed as film-forming substances (anti-fogging agents) with the aim of satisfying both of the above important properties, but it is difficult to satisfy both properties at the same time. Nothing that can be expected to have a sufficient effect has yet been obtained. The present inventors overcame the above-mentioned difficulties and conducted various studies on antifogging agents that can be suitably used. As a result, the present inventors discovered that a specific surfactant can be used extremely advantageously, and completed the present invention. That is, the present invention has the general formula (In the formula, R ¹ is an alkyl group having 8 to 12 carbon atoms, and R ² to ^{R 4} are the same or different and each represents hydrogen, an alkyl group having 1 to 12 carbon atoms, a hydroxy lower alkyl group, or a polyoxyethylene group. The present invention relates to an anti-fogging agent for glass, characterized in that it contains at least one surfactant represented by (except when R ² , R ³ and R ⁴ are hydrogen at the same time). By using the surfactant specified in the present invention, that is, the amine salt of dialkyl sulfosuccinic acid, the durability and transparency, which have conventionally been problems in antifogging agents, are completely improved. Although it is not clear on what principle the surfactant used in the present invention exerts its excellent effects, it is generally known that sodium salts of dialkyl sulfosuccinic acids are effective in lowering the surface tension of water. This is thought to be because by converting this into a specific amine salt, the adhesion to the glass surface increases without impairing the surface tension, and the compound becomes more difficult to crystallize. In the compound represented by the general formula (1) used in the present invention, the polyoxyalkylene group is preferably, for example, a polyoxyethylene group, a polyoxypropylene group, or a poly(oxyethylene-oxypropylene) block copolymer group. Illustrated. Representative examples of the compound of general formula (1) include dihexylsulfosuccinate octylamine salt, di(n-octyl)sulfosuccinate triethylamine salt, dioctylsulfosuccinate butylamine salt, and di(2-ethylhexyl)sulfosuccinate triethanolamine salt. , di(2-ethylhexyl)sulfosuccinic acid polyoxyethylene (10) laurylamine salt (the number in brackets indicates the total number of moles of ethylene oxide added. The same applies hereinafter), dinonylsulfosuccinic acid monoethanolamine salt, didecylsulfosuccinic acid Examples include polyoxyethylene (20) stearylamine salt, dilaurylsulfosuccinic acid diethanolamine salt, and the like. The compounds represented by the general formula (1) may be used alone or in combination of two or more. Further, in the present invention, in addition to the compound of general formula (1), other compounds may be mixed and used as necessary. Examples of these other compounds include water-soluble polymers such as polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, polyacrylamide, amine salts of polyacrylic acid, cellulose ethers, and surfactants such as alkylbenzene sulfonates, alkyl Ionic surfactants such as sulfate ester salts, alkyl phosphate ester salts, and polyoxyethylene adducts thereof, as well as polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl ethers,
Mention may be made of nonionic surfactants such as polyoxyethylene alkylamides. The mixing ratio of these optionally added compounds and the compound represented by general formula (1) is such that the latter is at least 5% (by weight, the same applies hereinafter), preferably at least 10%. The antifogging agent of the present invention can be easily obtained by dissolving a surfactant represented by the general formula (1) in water or/and an organic solvent, usually at a concentration of about 0.01% or more. The anti-fogging agent is used by applying it to the glass surface with a cloth, for example, but it can also be used as an aerosol type by filling the above solution together with a propellant into an aerosol can. Examples of the organic solvent used in the present invention include water-soluble organic solvents such as ethanol, isopropanol, ethylene glycol, propylene glycol, methyl cellosolve, and ethyl cellosolve, which may be used alone or in combination. I can do it. Further, easily volatile water-insoluble organic solvents such as trichlorotrifluoroethane and trichloromonofluoromethane can be used alone or in combination with the above-mentioned water-soluble organic solvents. The present invention will be explained in detail below with reference to Examples. It should be noted that the term % simply refers to % by weight unless otherwise specified. Examples 1 to 4 Each of the surfactants or mixtures of surfactants and water-soluble polymers shown in Table 1 was dissolved in a water/ethanol (30/70 weight ratio) solution to a concentration of 0.5%, and a predetermined amount of this solution was dissolved. was filled into a metal aerosol can and fitted with a valve. This aerosol can was further filled with dichlorodifluoromethane (Freon 12) as a propellant so that the ratio of Freon 12 to the above solution was 15/85 (weight ratio) to prepare an antifogging agent of the present invention. In the table, POE is an abbreviation for polyoxyethylene. Furthermore, the polyvinylpyrrolidone blended in Example 4 has a molecular weight of 30,000 and is generally used to impart a moisturizing effect to antifogging agents. Comparative Examples 1-2 Two types of commercially available aerosol type anti-fogging agents (A, B) are used as the anti-fogging agents of Comparative Examples 1 and 2. The active ingredients of the antifogging agent are as shown below. *Anti-fog agent A Γ polyoxyethylene nonylphenol ether (number of moles of ethylene oxide added: 30) 20% by weight Γ polyethylene glycol (molecular weight 200)
75% by weight Γ diethanolamine 5% by weight *Anti-fog agent B Γ polyoxyethylene lauryl sulfate ammonium salt (number of moles of ethylene oxide added)
20) 10% by weight Γ polyoxyethylene nonylphenol ether (number of moles of ethylene oxide added: 30) 10% by weight Γ polyethylene glycol (molecular weight 2000)
75% by weight Γtriethanolamine 5% by weight Comparative Examples 3 to 5 Comparative anti-fogging was carried out in the same manner as in Example 1 except that the surfactant or the mixture of surfactant and water-soluble polymer listed in Table 1 was used. A drug was created.

【table】

[Table] Anti-fog test Using the anti-fog agents of Examples and Comparative Examples, the durability of the anti-fog effect and the transparency of the film were tested by the following method. The results are shown in Table 2. (1) Sustainability of anti-fog effect Spray the anti-fog agent evenly onto the surface of a glass piece measuring 15 cm long, 5 cm wide and 0.1 cm thick by moving it back and forth vertically for about 3 seconds, then wipe it off lightly with a cotton cloth. .
The treated glass test piece is closely fixed to a glass window of a constant temperature water bath. When the room temperature was 25°C and the relative humidity was 65%, 5°C water was circulated in a constant temperature water bath, and the degree of cloudiness on the surface of the glass test piece was observed over time. (2) Transparency of coating A glass test piece treated in the same manner as in (1) above is stored in a constant temperature and humidity chamber at 60°C and 20% relative humidity for 5 hours. The sample is taken out of the constant temperature and humidity chamber and the transparency of the glass surface is observed using transmitted and reflected sunlight.

【table】

[Table] Example 5 Di(2-ethylhexyl)sulfosuccinic acid
Two types of anti-fogging agents were prepared in the same manner as in Example 1 except that POE(10) laurylamine salt or dioctyl sulfosuccinic acid monoethanolamine salt was used alone, and the sustainability of the anti-fogging effect and The transparency of the film was tested. As a result, the above 2
No matter which type of anti-fog agent was used, in the durability test of the anti-fog effect, no fogging occurred even after 6 hours, and in the transparency test, the glass piece was completely transparent and untreated. It was in almost the same condition.

Claims (1)

[Claims] 1. General formula (In the formula, R ¹ is an alkyl group having 8 to 12 carbon atoms, and R ² to ^{R 4} are the same or different and each represents hydrogen, an alkyl group having 1 to 12 carbon atoms, a hydroxy lower alkyl group, or a polyoxyethylene group. An anti-fogging agent for glass, characterized in that it contains at least one surfactant represented by the following (except when R ² , R ³ and R ⁴ are hydrogen at the same time).