JPH11349931A - Water repellent and its treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water repellent capable of readily forming a water repellent coating film having excellent water repellency and water repellency persistence simply by spreading thereof on a surface to be treated by compounding a fluoroalkyl-containing alkoxysilane with a catalyst for hydrolysis, an alcohol and a specific volatile solvent. SOLUTION: This water repellent comprises 100 wt.% of the sum total of (A) 0.5-5 wt.% of a fluoroalkyl-containing alkoxysilane having an alkoxy (e.g. heptadecafluorodecyltrimethoxysilane), (B) 0.001-2 wt.% of a catalyst for hydrolysis (preferably a strong acid catalyst such as hydrochloric acid), (C) >=73 wt.% of an alcohol selected from ethanol, i-propyl alcohol and n-propyl alcohol and (D) l-20 wt.% of a volatile solvent having 110-200 deg.C boiling point (preferably a hydrocarbon-based solvent such as an isoparaffinic hydrocarbon). The objective water repellent is preferably obtained by a method for premixing respective components other than the component B and then compounding the component B therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water repellent and a method for treating the same, and more particularly to a water repellent coating having excellent water repellency and excellent water repellency by simply spreading on a surface to be treated. The present invention relates to a water repellent that can be formed and a method for treating the same.

[0002]

2. Description of the Related Art Conventionally, a water-repellent material for glass which can impart water repellency to a surface to be treated such as a glass surface such as a window glass in an automobile, a ship, a vehicle, or the like. There was an agent. This water repellent for glass,
For example, when the treatment is performed on a windshield of an automobile or the like, it is possible to secure a good view in high-speed running in rainy weather or the like.

As the water repellent for glass, for example, a composition comprising an alkylpolysiloxane and one acid selected from the group consisting of sulfuric acid, phosphoric acid, aromatic sulfonic acid, aliphatic sulfonic acid and hydrochloric acid (particularly, Japanese Patent Publication No. 50-15473), a water repellent treatment agent for the surface of an inorganic material, characterized by dissolving an organopolysiloxane containing dimethylpolysiloxane as a main component and a specific fluorinated sulfonic acid in a volatile solvent. 63-67828), a water repellent for automotive window glass containing an amino-modified silicone oil and a surfactant in water and / or a water-soluble organic solvent (JP-A-5-301742), an alcohol solution Containing a specific amount of fluoroalkylsilane, a specific amount of acid catalyst and a specific amount of water (Japanese Patent Laid-Open No. 5-31)
No. 1156), a long-lasting water repellent containing a fluoroalkylsilane, a strong acid or strong alkali catalyst, a solvent containing alcohols as a main component, and insoluble fine powder (Japanese Patent Laid-Open No. 8-27).
No. 7388), a two-component liquid comprising an anhydrous solvent mainly composed of an alkoxy group-containing fluoroalkylsilane, a strong acid or strong alkali catalyst and an alcohol that dissolves the alkoxy group-containing fluoroalkylsilane, and a lower concentration aqueous solution of a specific alcohol. A long-lasting water-repellent agent for glass (Japanese Patent Application Laid-Open No. 9-104861), a specific fluoroalkyl group-containing alkoxysilane, a specific alkoxysilane,
A water repellent composition containing a hydrolysis catalyst and an organic solvent (JP-A-9-13017), containing an alcohol, a specific fluoroalkyl group-containing alkoxysilane, a specific both-end hydroxyl group-containing organosiloxane, and a hydrolysis catalyst. Water repellent composition (JP-A-9-176622).

However, when a composition comprising the alkylpolysiloxane and the acid is employed as the glass water repellent, for example, the water repellency cannot be maintained for a long time, and the water repellency is inferior. In the case where a water repellent for window glass of an automobile containing the amino-modified silicone oil and a surfactant is employed, for example, a problem that sufficient water repellency cannot be imparted to the glass surface. When the long-lasting water-repellent is used, for example, there is a problem that an excellent water-repellent coating cannot be easily formed.

[0005] In the long-lasting water repellent, particularly,
When this long-lasting water repellent is applied to a glass surface, for example, after the water repellent treated surface is dried, excess water repellent components must be removed from the water repellent treated surface. In addition, there has been a problem that the wiping operation for removing the excess water repellent component is complicated and labor intensive.

[0006] An object of the present invention is to solve conventional problems.

An object of the present invention is to provide a water-repellent agent capable of easily forming a water-repellent film having excellent water-repellency and water-repellency lasting simply by spreading on a surface to be treated, and a method for treating the same. It is in.

[0008]

The first means for solving the above-mentioned problems is that (A) 0.5 to 5% by weight of a fluoroalkyl group-containing alkoxysilane having an alkoxy group,
(B) 0.001-2% by weight of a hydrolysis catalyst, and (C)
At least 73% by weight or more of at least one alcohol selected from the group consisting of ethanol, i-propyl alcohol and n-propyl alcohol;
A water repellent characterized by containing 1 to 20% by weight of a volatile solvent having a temperature of 0 to less than 200 ° C. so that the total amount thereof becomes 100% by weight. In the above, the volatile solvent is at least one hydrocarbon solvent selected from the group consisting of isoparaffinic hydrocarbons, normal paraffinic hydrocarbons, aromatic hydrocarbons, and naphthenic hydrocarbons. A second means for solving the problem is a method for treating a water repellent, which comprises drying the water repellent treated surface after spreading the water repellent on the surface to be treated.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The water repellent of the present invention comprises (A) a fluoroalkyl group-containing alkoxysilane (hereinafter sometimes referred to as component A) and (B) a hydrolysis catalyst (hereinafter referred to as "component A").
Sometimes referred to as B component. ), (C) alcohol (hereinafter sometimes referred to as C component), and (D) volatile solvent (hereinafter sometimes referred to as D component). — (A) Fluoroalkyl group-containing alkoxysilane— The fluoroalkyl group-containing alkoxysilane in the present invention is, for example, a compound represented by the general formula: CF ₃ (CF ₂ ) _m (CH ₂ )
₂ SiR _n X _3-n (where R represents a hydrocarbon group, X represents an alkoxy group, m represents any integer of 5 to 9, and n represents any integer of 0 to 2). it can.

Examples of the hydrocarbon group include an alkyl group (which may also be referred to as a “C _r H _{2r + 1} group”), an alkenyl group, a phenyl group having an alkyl group, and the like. C 1-18 (“r is 1-1”
8 ". ) Any of the alkyl groups,
Any alkenyl group having 1 to 18 carbon atoms is preferable, and any alkyl group having 1 to 4 carbon atoms (the above-mentioned r can also be indicated as 1 to 4) is more preferable.

The alkoxy group (also referred to as “OC _s H _{2s + 1} group”) includes, for example, a methoxy group,
Examples thereof include an ethoxy group, a propoxy group and a butoxy group. In the alkoxy group, the number of carbon atoms is 1
To 3 (“s” may be indicated as 1 to 3).

M in the above general formula is an integer of 5 to 9, and when m is an integer of 5 to 9, excellent water repellency can be realized.
Is preferably an integer of any of 4 to 8. In other words, the fluoroalkyl group-containing alkoxysilane contains a fluoroalkyl group having 6 to 10 carbon atoms (hereinafter sometimes referred to as an “Rf group”),
In particular, it preferably contains an Rf group having 5 to 9 carbon atoms.

[0013] In the above general formula, n is an integer of 0 to 2, and it is particularly preferable that n is 0 or 1. When the n is 0 or 1, for example, the alkoxy group and the surface to be treated can more effectively react with each other, for example, the alkoxy group and the OH group on the glass surface. Nature can be realized.

The mixing ratio of the fluoroalkyl group-containing alkoxysilane in the water repellent of the present invention is from 0.5 to 5% by weight, preferably from 0.5 to 5% by weight, so that the total of the components A to D becomes 100% by weight. -4% by weight. When the mixing ratio of the component A is less than 0.5% by weight, when the water repellent is spread on the surface to be treated, excellent water repellency can be imparted uniformly to the entire surface treated with the water repellent. I ca n’t,
If the blending ratio of the component A is more than 5% by weight, the component A is excessively treated on the surface to be treated when the water repellent is spread on the surface to be treated. Problems such as fogging of the treated surface occur, and the work of removing the excessive A component must be performed, so that a water-repellent coating cannot be easily formed. The component A may be used alone or in combination of two or more. — (B) Hydrolysis Catalyst— The hydrolysis catalyst in the present invention has a function as a catalyst in the hydrolysis reaction of the alkoxy group in the component A.

Examples of the hydrolysis catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid; organic acids such as formic acid, acetic acid, oxalic acid, and benzoic acid; and ammonia, sodium hydroxide, and potassium hydroxide. Inorganic base, ethylenediamine,
Examples thereof include organic bases such as alkanolamines, and particularly preferred are strong acid catalysts such as hydrochloric acid, sulfuric acid, and nitric acid.
When the strong acid catalyst is employed as the hydrolysis catalyst,
A water-repellent coating having excellent water-repellency and water-repellency persistence can be formed more effectively, and excellent storage stability of the water-repellent agent can be realized.

The mixing ratio of the hydrolysis catalyst in the water repellent of the present invention is from 0.001 to 2% by weight, particularly from 0.005 to 1%, so that the sum of the components A to D becomes 100% by weight.
It is selected within the range of weight%. When the blending ratio of the component B is less than 0.001% by weight, for example, a problem such as a slow reaction rate in a hydrolysis reaction of the alkoxy group in the component A occurs, and a sufficient catalytic function is exhibited. When the compounding ratio of the component B exceeds 2% by weight, for example, problems such as deterioration in storage stability of the water repellent are caused. If the amount is out of the range of 0.001 to 2% by weight, a water-repellent coating having excellent water repellency and water repellency persistence cannot be formed. The B component may be used alone or in combination of two or more. — (C) Alcohol— The alcohol in the present invention is at least one alcohol selected from the group consisting of ethanol, i-propyl alcohol, and n-propyl alcohol, and is a monohydric alcohol having 2 or 3 carbon atoms. In other words,

The alcohol has a function of effectively dissolving the component A and the like, and the alcohol evaporates after spreading the water repellent on the surface to be treated, for example, so that the alcohol quickly evaporates. A water-repellent coating can be formed thereon.

The alcohol has a function of improving the storage stability of the water repellent.

The mixing ratio of the alcohol in the water repellent of the present invention is appropriately selected to be 73% by weight or more so that the total of the components A to D becomes 100% by weight. Said C
The components may be used alone or in combination of two or more. — (D) Volatile Solvent— The volatile solvent in the present invention has a boiling point of 110 ° C. or more and less than 200 ° C., and for example, a hydrocarbon solvent or the like can be suitably used.

Examples of the hydrocarbon solvent include at least one hydrocarbon solvent selected from the group consisting of isoparaffinic hydrocarbons, normal paraffinic hydrocarbons, aromatic hydrocarbons, and naphthenic hydrocarbons. Can be mentioned.

In the present invention, by employing a volatile solvent having a boiling point of 110 ° C. or more and less than 200 ° C., the leveling property of the water repellent on the surface to be treated can be improved. Wiping of excess components after spreading the water repellent on the surface, water wiping,
There is no need to perform wiping work such as dry wiping work.

From this point of view, the volatile solvent in the present invention has, for example, a function of lubricating the surface to be treated so that the water repellent can be easily spread on the surface to be treated,
The volatile solvent has a function of effectively leveling the water-repellent agent, a function of improving the fixability of the water-repellent film, and the like. Therefore, the volatile solvent may be referred to as a lubricant, a leveling agent, a film fixing aid, or the like.

The volatile solvent has a boiling point of 1
When the temperature is lower than 10 ° C., the volatility of the volatile solvent becomes too strong. For example, when the water repellent is spread on the surface to be treated,
Since the volatile solvent evaporates before the water-repellent agent is sufficiently leveled, problems such as the inability to form an excellent water-repellent coating occur. When the boiling point exceeds 200 ° C, the volatile solvent is removed. When the water repellent on the surface to be processed is spread, the volatile raw solvent hardly evaporates and remains on the surface to be processed. Since the amount of the component A contained in the agent is small, it is not possible to form a sufficient water-repellent film, and when the film is spread too thick, the volatile solvent on the surface to be treated is agglomerated, and Since the above-mentioned component A collects, a uniform water-repellent coating cannot be formed.

Also, since it takes time until the volatile solvent evaporates and the component A is fixed on the surface to be treated, when the water repellent is spread on the surface to be treated, it remains on the surface to be treated. The volatile solvent prevents the fixation between the component A and the surface to be treated, causing unevenness in the water-repellent coating, making it impossible to form a uniform water-repellent coating.

The proportion of the volatile solvent in the water repellent of the present invention is in the range of 1 to 20% by weight, preferably 4 to 10% by weight so that the sum of the components A to D becomes 100% by weight. Is selected from The mixing ratio of the component D is 1% by weight.
If the ratio is less than the above, the spreadability of the water repellent on the entire surface treated with the water repellent cannot be improved, and if the blending ratio of the component D exceeds 20% by weight, the wiping finishing work or the like is performed. Therefore, a water-repellent coating cannot be easily formed. The D component may be used alone or in combination of two or more. -(E) Additive- The water repellent of the present invention includes, for example, effectively dissolving the component A and the like, improving the compatibility between the components, and preventing unpleasant odor. For the purpose of improving the weather resistance, for example, additives such as hydrocarbons, ketones, esters, ethers, fragrances, and ultraviolet absorbers (hereinafter, may be referred to as “E component”) are blended. be able to. -Method for preparing water repellent-The water repellent of the present invention can be prepared, for example, into a prepared solution such as a uniform solution by mixing the above-mentioned components A to E in a predetermined container at room temperature. However, from the viewpoint of further suppressing the reaction of the hydrolyzable group, it is preferable to mix the components other than the component B in advance and then mix the component B last.

The above-mentioned preparation liquid can be filled in a predetermined container such as a bottle, a spray can, an aerosol can or the like. -Water repellent treatment method-The water repellent of the present invention, for example, on the surface to be treated such as a glass surface,
For example, spray coating, dipping, wiping,
It can be spread by brushing, sponge wiping, cloth wiping, towel wiping, flannel wiping, gauze wiping, coating material wiping of various thin materials such as cotton, wool, synthetic fiber, paper, etc. After spreading on the surface to be treated, the surface to be treated can be treated at room temperature by, for example, drying the surface treated with a water repellent by air drying or the like.

[0027]

Embodiments of the present invention will be described below in detail. (Examples 1 to 9 and Comparative Examples 1 to 6) Each component was blended at the blending ratio shown in Table 1 and Table 2 to prepare a water repellent. In addition,
Details of each component in Tables 1 and 2 are shown below. Rf group-containing alkoxysilane: heptadecafluorodecyltrimethoxysilane, Rf group-containing alkoxysilane: heptadecafluorodecyltriethoxysilane, Rf group-containing alkoxysilane: heptadecafluorodecyltriisopropoxysilane, isoparaffinic hydrocarbon solvent: EXXON CHE
MICALS “Isopar E” manufactured by Exxon Chemical Co., Ltd., boiling point 115-142 ° C. Isoparaffinic hydrocarbon solvent: EXXON CHE
MICALS “Exoper H” manufactured by Exxon Chemical Co., Ltd., boiling point: 174 to 190 ° C. Liquid paraffin: “MORES” manufactured by Matsumura Oil Research Co., Ltd.
CO WHITE P-70 ”, boiling point: 311 ° C. Dimethyl silicon:“ S ”manufactured by Toray Dow Corning Co., Ltd.
H-200 (350C / S) ", boiling point: 350 ° C

[0028]

[Table 1]

[Table 2] By the flannel impregnated with the water repellent, 150 mm long ×
After spreading the water repellent on a glass plate 150 mm wide and 5 mm thick, the surface of the glass plate treated with the water repellent was 3
After drying at room temperature (25 ° C.) for 0 minutes, a water-repellent coating was formed on the glass surface, and the following evaluation was performed. Table 3 shows the results.

<Leveling Property> When the water repellent was spread, the flannel was moved in a circle on the glass surface until the water repellent spread evenly on the glass surface. The number of times that the flannel was moved so as to draw a circle and spread uniformly was counted, and evaluated according to the following criteria.

3 times or less ··· ◎ 4 to 5 times ··· 〇 6-9 times ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ △ More than 10 times-can be spread uniformly Not possible ... x <Initial water repellency> After drying the surface treated with the water repellent, drops of water are dropped on the water repellent coating arranged horizontally, and the contact angle of water is measured. The evaluation was based on the following criteria. 100 ° or more ◎ 95 to 100 °・ 〇 90 ~ 95 ° ・ ・ ・ ・ ・ ・ ・ ・ Less than 90 ° ···· × <Water repellency> A sponge is coated with an oil film remover for glass (“Clean View Special” manufactured by Taiho Kogyo Co., Ltd.), and this sponge is circled 50 times on the water repellent treated surface. After rubbing, wash the water repellent treated surface with water and dry,
A water drop was dropped on the water-repellent coating arranged horizontally, and the contact angle of water was measured, and evaluated based on the same criteria as the initial water-repellency.

[0031]

[Table 3]

According to the present invention, there is provided a water repellent and a water repellent which can easily form a water repellent coating having excellent water repellency and water repellency by simply spreading on the surface to be treated. A processing method can be provided.

Claims (3)

[Claims] (A) 0.5 to 5% by weight of a fluoroalkyl group-containing alkoxysilane having an alkoxy group,
(B) 0.001-2% by weight of a hydrolysis catalyst, and (C)
At least 73% by weight or more of at least one alcohol selected from the group consisting of ethanol, i-propyl alcohol and n-propyl alcohol;
1 to 20% by weight of a volatile solvent having a temperature of 0 ° C or higher and lower than 200 ° C
Are contained so as to be 100% by weight in total. 2. The method according to claim 1, wherein the volatile solvent is at least one hydrocarbon solvent selected from the group consisting of isoparaffinic hydrocarbons, normal paraffinic hydrocarbons, aromatic hydrocarbons, and naphthenic hydrocarbons. Item 7. The water repellent according to Item 1. 3. A method for treating a water-repellent agent, comprising spreading the water-repellent agent according to claim 1 on the surface to be treated, and then drying the treated surface.