JPH0741336A - Water repellent for glass - Google Patents

Abstract

PURPOSE:To obtain a water repellent for glass usable even in the presence of moisture, easy to handle and having high safety by blending specified amino modified polysiloxane with formic acid and water. CONSTITUTION:This water repellent for glass consists of 0.01-10.0wt.% amino modified polysiloxane represented by the formula [where each of X and Y is methyl or alkoxy and each of (m) and (n) is an integer of >=1 giving 10-10,000est viscosity at, 25 deg.C and 300-10,000 amine equiv.], 0.001-5wt.% formic acid and the balance water, ROH (R is 1-3C alkyl) or aq. soln. contg. ROH.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water repellent treatment agent for imparting water repellency to a glass surface of a vehicle or the like.

[0002]

2. Description of the Related Art Conventionally, silicone-based water repellents are commercially available. These are obtained by adding a strong acid such as sulfuric acid, aromatic sulfonic acid, aliphatic sulfonic acid or hydrochloric acid to an alcohol solution of alkylpolysiloxane.

[0003]

The conventional water repellent is one which is uniformly applied to a glass surface having no water and dried, and then the whitened component is washed off with water and used. When water is present on the glass surface, the polysiloxane component is separated, and the acid component is diluted so that it does not act effectively on the glass surface and the water repellency decreases.

For this reason, it is necessary to remove the moisture on the glass surface, although it is often used during rainfall. In addition, since the component contains a strong acid, it is dangerous in handling.

The present invention can be used even in the presence of moisture,
It is intended to provide a water repellent that is easy to handle and highly safe.

[0006]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems and comprises 0.01 to 10.0% by weight of an amino-modified polysiloxane represented by the following general formula [1]
Formic acid is 0.001 to 5% by weight, and the balance is water or ROH (R
Is a water-repellent agent for glass, which is composed of an aqueous solution containing an alkyl group having 1 to 3 carbon atoms) or ROH.

Embedded image (where X and Y are methyl groups or alkoxy groups. M and n are 10 to 10,000 e at a viscosity of 25 ° C.)
st, an integer of 1 or more in which the amine equivalent is in the range of 300 to 10,000. )

That is, the water repellent agent of the present invention comprises an amino-modified polysiloxane and formic acid dissolved in water or an aqueous alcohol solution. The terminal of the amino-modified polysiloxane may be a methyl group, but an alkoxy group is preferable. This is because the alkoxy group can be hydrolyzed in the presence of water to cause a crosslinking reaction, and can react with SiOH on the glass surface to be chemically adsorbed on the glass surface.

The acid used in the present invention reacts with the amino-modified polysiloxane to increase the water solubility, and at the same time, acts as a catalyst for the crosslinking reaction of the alkoxy group. An excellent water-repellent effect cannot be obtained in a system containing no acid.

As the acid, a strong acid such as sulfuric acid or sulfonic acid as in the past is not required, but a carboxylic acid such as formic acid is sufficient. As the carboxylic acid, formic acid is preferable because of its high reactivity, but acetic acid and the like can be used in combination as necessary. Therefore, a highly safe water repellent can be obtained. Further, since the acid acts as a catalyst, it may be present in a small amount. Excessive acid causes a decrease in initial water repellency.

When the amino-modified polysiloxane contains an alkoxy group at the terminal, it is preferable that the solution contains alcohol. This is because the alcohol prevents the alkoxy group from being hydrolyzed and polymerized in the solution.

In addition to these components in the present invention, a surfactant usually used may be added for stabilization. In this case, a cationic or nonionic surfactant or the like is selected. However, a large amount of activator causes a decrease in water repellency.

The water repellent treatment agent of the present invention can be used in various forms. For example, a water-repellent automobile window washer liquid may be used. In this case, the same operation as that of a conventional window washer containing a surfactant and alcohol as main components may be performed. It can be used while running, and the windshield surface can be treated to be water repellent in rainy weather.

It can also be used as a glass cleaner. It can be used as a glass cleaner that can perform water repellent treatment as well as unprecedented cleaning, and the glass surface is water repellent, so the finish is quick.

In addition, by prescribing with an alcohol base, it can be used as a deicer and a defroster capable of water repellent treatment. At the same time that the alcohol melts ice and frost, the amino-modified polysiloxane is adsorbed on the glass and imparts water repellency. As a result, the adhesion of ice or frost to the glass is reduced and it is easy to remove.

In addition to the above, the water repellent treatment agent of the present invention can be used as an aerosol according to these uses by a conventional method.

[0016]

According to the method of the present invention, the amino-modified polysiloxane is first adsorbed on the glass surface. Then, in the presence of water adsorbed on the glass surface or water in the solution, the alkoxy group is hydrolyzed using an acid as a catalyst to cause a crosslinking reaction, and also reacts with SiOH groups on the glass surface. By chemically bonding in this way, the adhesiveness to the glass surface and the water repellency are improved.

In the method of the present invention, it suffices to bring the solution containing the amino-modified polysiloxane into contact with the glass surface, and does not require the conventional drying operation. It is also characterized in that a very low concentration of siloxane is sufficient and the reaction is extremely rapid.

[0018]

[Examples and Comparative Examples]

 Example 1 Water repellent * Amino-modified polysiloxane 2.0 wt% 88% Formic acid 0.5 Isopropyl alcohol 92.5 Ion-exchanged water 5.0 Comparative example Dimethyl polysiloxane 2.0 wt% Sulfuric acid 0.5 Isopropyl alcohol 97.5

* Amino-modified polysiloxane: One or more selected from the following examples can be used. The same applies to the other examples.

[0020]

A glass plate which was thoroughly washed and wet with water having no water repellency was prepared. After spraying ion-exchanged water evenly by spraying, 2 ml each of the liquids of Example and Comparative Example were dropped with a dropper, spread with a wiper of an automobile, immediately spread, and immediately rinsed with running tap water to examine the water repellency of the glass surface. The glass surface treated with the liquid of Example 1 was uniform and had good drainage and showed good water repellency, but the glass surface treated with the liquid of Comparative Example was inferior in water repellency and partially wetted.

Example 2 Water-repellent window washer Amino-modified polysiloxane 0.5w
t% 88% Formic acid 0.1 Dialkyl (C ₁₂ ) ammonium chloride 0.5 Methanol 25.0 Ion-exchanged water 73.9

300 ml of the above adjusting solution was placed in a car washer tank and diluted 6 times with tap water. When used in the same way as a normal washer while running in the rain, the windshield surface showed good water repellency, and the raindrops were small, resulting in good visibility.

Example 3 Water-repellent glass cleaner Amino-modified polysiloxane 0.2 wt% 88% Formic acid 0.05 Isopropyl alcohol 15.0 Ion-exchanged water 84.75

An aerosol was prepared by filling LPG gas in an amount of 30 ml with respect to 270 ml of the above adjustment liquid. After spraying, the glass surface immediately became water-repellent, and the liquid became fine water droplets, so it was possible to obtain a glass cleaner that dries quickly and finishes quickly.

Example 4 Water repellent type deicer Amino inspection polysiloxane 0.5 wt% Acetic acid and formic acid 0.1 Isopropyl alcohol 24.4 Ethanol 40.0 Ethylene glycol 35.0

An aerosol was prepared by filling 120 ml of the LPG gas with respect to 180 ml of the above adjustment liquid. When the glass plate was wetted with water and frozen, it was sprayed and thawed, and the glass surface showed water repellency.

[0028]

The water-repellent agent of the present invention can be used in the presence of water, unlike the conventional ones, and it does not require an operation of simply drying it by bringing it into contact with a liquid. Also, the acidity is weak and the safety is high. Therefore, in addition to a water repellent that can be used even in rainy weather, it has the property of being widely applicable to window washers, glass cleaners, and deicers.

Claims (1)

[Claims] 1. An amino-modified polysiloxane represented by the following general formula [1] (Formula 1) is 0.01 to 10.0% by weight, formic acid is 0.001 to 5% by weight, and the rest is water or ROH.
(R is an alkyl group having 1 to 3 carbon atoms) or an aqueous solution containing ROH. [Chemical 1] (However, X and Y in the formula are methyl groups or alkoxy groups. M,
n has a viscosity of 10 to 10,000 est at 25 ° C. and an amine equivalent of 300 to 10,000. 1
Greater than or equal to an integer. )