JPH0913017A - Water repellent composition - Google Patents

Abstract

PURPOSE: To obtain a water repellent composition which can impart good persistent water repellency to e.g. the window glass of an automobile by mixing two specified alkoxysilanes with a hydrolysis catalyst and an organic solvent in a specified ratio. CONSTITUTION: This water repellent composition is obtained by mixing 0.05-10wt.% fluoroalkyl-containing alkoxysilane (e.g. heptadecafluorodecyltrimethoxysilane) represented by formula I (wherein R is a monovalent hydrocarbon group or the like; X is a hydrolyzable group; (m)is 0-10; (n)is 2-10; and (p) is 0-2) with 0.05-10wt.% alkoxysilane (e.g. dimethyldimethoxysilane) represented by formula II (wherein R<1> is a monovalent hydrocarbon group; Y is a hydrolyzable group; and (q)is 1-3), 0.001-10wt.% hydrolysis catalyst (e.g. hydrochloric acid) and 2-99.8wt.% organic solvent (e.g. methanol). This composition is applicable to a substrate at room temperature without heating and can impart excellent water repellency to a substrate without the necessity for aftertreatment such as wiping.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water repellent composition which forms a film having good water repellency by treating a substrate, and more specifically, by treating a window glass of an automobile, a ship or the like, The present invention relates to a water repellent composition capable of imparting water repellency effective for securing a visual field even in the rain.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION AND ITS PROBLEMS Conventionally, as a water repellent agent for glass, a composition in which polydimethylsiloxane is dispersed in a solvent such as alcohol is commercially available. However, these compositions have a problem that the persistence of water repellency is not sufficient, and on the other hand, a water repellent composition containing a fluoroalkylsilane or the like has been proposed. For example,
A method of forming a water-repellent coating on a substrate such as glass by using two or more kinds of fluoroalkyl group-containing alkoxysilanes having different molecular chain lengths (see JP-A-5-96679), and a silane compound having a fluorine atom. A method of coating a glass surface with water repellency (see Japanese Patent Application Laid-Open No. 5-96681), a water repellent such as a fluoroalkyl group-containing alkoxysilane, and an aqueous solution of hydrosilicofluoric acid saturated with silicon dioxide. A method of imparting water repellency by forming a mixture on the surface of a substrate (see JP-A-5-97474, JP-A-5-97477 and JP-A-5-97478), and organosilazane containing a perfluoroalkyl group. A film-forming agent composition comprising a polymer and an organic solvent, which imparts water repellency (JP-A-5-31
1121), fluoroalkylsilane, acid catalyst,
A water repellent treatment agent comprising alcohol and water (JP-A-5-31
1156), a partial hydrolyzate of a fluoroalkylsilane and a metal alkoxide, a water repellent treatment agent containing water and an acid catalyst (see JP-A-5-319867), and the like. However, in the water repellent agent using the fluoroalkyl group-containing silane shown in these, it is necessary to use a special solvent, and heat treatment is necessary.
Alternatively, there is a problem that post-treatment such as wiping is required. Further, the resulting water-repellent treated glass repels water to form water droplets, and the water repellency evaluated from the contact angle in this case is good, but the drop of the water droplets from the treated glass surface is not always sufficient, When the treated glass is used as a window glass for automobiles, further improvement has been desired in order to obtain good visibility.

[0003]

The present invention can perform treatment at room temperature without heating, can impart good water repellency with excellent durability, and can easily drop water droplets from the treated surface, resulting in good visibility. It is an object of the present invention to provide a water repellent composition capable of obtaining a water repellent treated glass or the like that can secure the above. As a result of intensive studies to solve the above problems, the present inventors have found that a fluoroalkyl group-containing alkoxysilane is used as a main component, a specific alkoxysilane is blended with this, and further a hydrolysis catalyst and an organic solvent are used. The inventors have found that a water repellent composition having good characteristics can be obtained, and have completed the present invention. That is, the water repellent composition of the present invention comprises (A) a general formula CF ₃ (CF ₂ ) _m (CH ₂ ) _n SiR _p X _3-p (1) (wherein R is a substituted or unsubstituted monovalent group). Hydrocarbon groups of,
X is a hydrolyzable group, m is an integer of 0-10, n is an integer of 2-10, and p is an integer of 0-2)
10.0% by weight (B) General formula R ¹ _q SiY _4-q (2) (wherein R ¹ is the same or different unsubstituted monovalent hydrocarbon group, Y is a hydrolyzable group, and q is 1 to Represents the integer of 3)
0.05 to 10.0% by weight (C) hydrolysis catalyst 0.001 to 10.0% by weight (D) 2.0 to 99.8% by weight of an organic solvent.

The component (A) of the present invention is a fluoroalkyl group-containing alkoxysilane represented by the general formula (1). In the formula, R represents a substituted or unsubstituted monovalent hydrocarbon group, an alkyl group such as a methyl group, an ethyl group, a propyl group and a hexyl group, an alkenyl group such as a vinyl group and an allyl group, a cyclopentyl group, a cyclohexyl group. Such as cycloalkyl group, cyclohexenyl group, cycloalkenyl group such as cyclo-2,4-hexadienyl group, aryl group such as phenyl group and tolyl group, aralkyl group such as benzyl group, phenylethyl group and styryl group, or these Examples thereof include those in which a part of the group is substituted with a halogen atom, an amino group, a hydroxyl group, an alkoxy group or the like. Among these, an alkyl group having 1 to 18 carbon atoms and an aryl group are preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable, because the resulting coating film has good water repellency. See also X
Represents a hydrolyzable group, an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, an n-propoxy group, and an n-butoxy group, and an aminoxy group, a ketoxime group,
Examples thereof include acetoxy group, amide group, and alkenyloxy group. Among them, an alkoxy group is preferable because a composition having a good pot life can be obtained, and the curability of the composition and the water repellency of the obtained coating are good. Especially, a methoxy group and an ethoxy group are preferable. In the fluoroalkyl group of the component (A), m is an integer of 0 to 10, and when it is in this range, a composition having good curability and water repellency can be obtained, and preferably an integer of 4 to 8 is there. And n
Is an integer of 2 to 10, and is preferably 2 because it is easy to synthesize the obtained raw material and good water repellency is obtained. In the component (A), p is an integer of 0-2,
It is preferably 0 or 1 because the resulting coating has good water repellency. As the component (A), specifically, CF
₃ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF
₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ , CF
₃ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) ₂ , CF ₃ (CF ₂ ) ₅ CH ₂ CH ₂ Si (CH ₃ ) (OCH
₃ ) ₂ , CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (CH ₃ ) (OCH ₃ ) _{2 and the} like. The amount of component (A) is 0.05 to 10.0 in the composition of the present invention.
%, Preferably 0.2 to 5.0% by weight. 0.0
If it is less than 5% by weight, good water repellency cannot be obtained.
If the amount exceeds 5% by weight, it cannot be uniformly applied to the surface of the substrate, and post-treatment such as wiping is required, which is not preferable.

The component (B) of the present invention is a hydrocarbon group-containing alkoxysilane represented by the general formula (2). In the formula, R ^1's represent the same or different unsubstituted monovalent hydrocarbon groups, alkyl groups such as methyl group, ethyl group, propyl group and hexyl group, alkenyl groups such as vinyl group and allyl group, cyclopentyl group , Cycloalkyl group such as cyclohexyl group, cyclohexenyl group, cycloalkenyl group such as cyclo-2,4-hexadienyl group, aryl group such as phenyl group and tolyl group, aralkyl group such as benzyl group, phenylethyl group and styryl group Are exemplified. Among these, an alkyl group having 1 to 18 carbon atoms is preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable, because the obtained coating film has good water repellency and water drops easily drop. In addition, Y is a hydrolyzable group, and the same substituents as those of the above X are exemplified, and among them, an alkoxy group is preferable because a composition having a good pot life can be obtained, and a methoxy group and an ethoxy group are particularly preferable. Further, in the component (B), q is an integer of 1 to 3, and is preferably 2 or 3, and particularly preferably 2 since the resulting coating has good water repellency and water drops easily drop. . component
Specific examples of (B) include CH ₃ Si (OCH ₃ ) ₃ and (CH ₃ ) ₂ Si (OCH
_{3) 2, (CH 3)} 3 Si (OCH 3), (CH 3) 2 Si (OC 2 H 5) 2, (C 4 H 9) (C
_{H 3) Si (OCH 3)} 2, (C 4 H 9) (CH 3) 2 Si (OCH 3), (C 6 H 13) Si (OC
_{H 3) 3, (C 6} H 13) (CH 3) Si (OCH 3) 2, (C 6 H 13) (CH 3) 2 Si (OC
_{H 3), (C 18 H} 37) (CH 3) Si (OCH 3) 2, (C 18 H 37) (CH 3) 2 Si (OCH
₃ ), (CH ₃ ) ₃ CSi (CH ₃ ) ₂ (OCH ₃ ) and the like. Ingredient (B)
The compounding amount is 0.05 to 10.0% by weight, preferably 0.2 to 5.0% by weight in the composition of the present invention. If it is less than 0.05% by weight, the drop of water droplets on the treated surface is insufficient,
If the amount is more than 10.0% by weight, it is not preferable because post-treatment such as wiping is required because the surface of the substrate cannot be uniformly applied.

The component (C) of the present invention serves as a hydrolysis catalyst for the components (A) and (B), and includes inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid and phosphoric acid, formic acid, acetic acid, propionic acid and oxalic acid. Acid, sulfonic acid, acetic anhydride, benzoic acid, and other organic acids, ammonia, sodium hydroxide, potassium hydroxide, and other inorganic bases, ethylenediamine, triethanolamine, and other organic bases are exemplified, with good pot life and water repellency. In that case, an inorganic acid or an organic acid is preferable, and hydrochloric acid or nitric acid is particularly preferable. The content of the component (C) is 0.001 to 10.0% by weight in the composition of the present invention, preferably 0.01
˜5.0% by weight, particularly preferably 0.2 to 2.0% by weight. If it is less than 0.001% by weight, the component (A) and the component (B)
A good water-repellent film is not formed on the surface of the base material due to insufficient hydrolysis rate, and if it is more than 10.0% by weight, it becomes difficult to obtain a good pot life of the composition, and further odor etc. The problem of occurs.

Component (D) of the present invention dissolves and disperses each component, and alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, t-butyl alcohol and methoxypropanol. Ether ethers and ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, tetrahydrofuran and dioxane, ketones such as acetone, methyl ethyl ketone and diethyl ketone, methyl acetate, ethyl acetate, acetic acid n
-Esters such as butyl, n-hexane, gasoline, rubber volatile oil, mineral spirits, aliphatic hydrocarbons such as kerosene, aromatic hydrocarbons such as benzene, toluene, xylene, octamethylcyclotetrasiloxane , Volatile silicones such as decamethylcyclopentasiloxane, hexamethyldisiloxane, and octamethyltrisiloxane are exemplified, and among them, since the composition has good pot life and coatability, ether alcohols and Alcohols are preferable, and isopropyl alcohol is particularly preferable. The organic solvent of component (D) may be used in combination of two or more kinds, and it volatilizes quickly to obtain good coatability without uneven coating and no post-treatment such as wiping is required. , Those with a boiling point less than 100 ° C, such as ethanol and isopropyl alcohol, and propylene glycol monomethyl ether,
It is preferable to use n-butyl alcohol having a boiling point of 100 ° C. or higher in combination, and particularly preferable to use those having a boiling point of 60 to 98 ° C. and 100 to 160 ° C. in combination. When used in combination, the ratio of the low boiling point solvent and the high boiling point solvent is preferably 2 to 50% by weight, particularly 5 to 20% by weight, in the organic solvent. The content of the component (D) in the composition of the present invention is 2.0 to 99.8% by weight, preferably 50.0 to 98.0% by weight. If it is less than 2.0% by weight, the composition has insufficient pot life and coatability, and
If it is more than 9.8% by weight, it becomes difficult to obtain a coating having sufficient water repellency.

The composition of the present invention further includes an anionic system,
Cationic, nonionic and amphoteric surfactants, metal anticorrosives, antifreezes, colorants, UV absorbers,
A fragrance or the like can be blended, and water can be used together as a solvent.

The method for preparing the composition of the present invention is not particularly limited and can be obtained by mixing the components at room temperature to form a uniform composition. Generally, the hydrolysis catalyst of component (C) is added last. A composition is prepared according to the procedure described above. The method for treating the substrate of the composition of the present invention is not particularly limited, and it may be applied uniformly by spray coating, dipping, wiping, brush coating, cloth wiping, etc., and good water repellent treatment can be achieved without heating. it can.

[0010]

Industrial Applicability The water repellent composition of the present invention can be treated at room temperature without heating and need not be subjected to post-treatment such as wiping and impart good water repellency excellent in durability. It has the feature that The glass treated with the water repellent of the present invention shows good water repellency, and further water drops generated on the surface easily drop, so that the visibility of the glass is kept good, especially for window glass of automobiles and ships. It is useful as a water repellent.

[0011]

The present invention will be described below in detail with reference to examples. In the examples, "part" means "part by weight" and "%" means "% by weight". Example 1 10 parts of propylene glycol monomethyl ether was added to 85 parts of isopropyl alcohol and mixed to homogenize. In this, heptadecafluorodecyltrimethoxysilane [C
2.0 parts of F ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ] and 2.0 parts of dimethyldimethoxysilane were added and mixed, and 1.0 part of nitric acid (61% concentration) was added as a hydrolysis catalyst. The treating agent was prepared by uniformly mixing. The obtained treatment agent was dip-coated on a glass substrate and air-dried at room temperature for 15 minutes to prepare a water-repellent treated glass plate. The appearance of this water-repellent treated glass plate was visually observed and the uneven coating was evaluated as follows. Also,
Water drop is placed on a water-repellent glass plate, and its initial contact angle and falling inclination angle are measured (Kyowa Scientific Co., Ltd., CA-A type)
And the water repellency was evaluated. Table 1 shows the results. Appearance ◯: Treated uniformly, no uneven coating. Δ: A slight haze due to uneven coating is seen. X: Haze due to uneven coating is seen.

Examples 2 to 8 A treating agent having the composition shown in Table 1 was prepared in the same manner as in Example 1, and the appearance and water repellency were evaluated in the same manner. Table 1 shows the results.

Comparative Example 1 A treating agent was prepared in the same manner as in Example 1 except that dimethyldimethoxysilane was not added and isopropyl alcohol was changed to 87 parts, and the appearance and water repellency were evaluated in the same manner. Table 1 shows the results.

Comparative Example 2 A treating agent was prepared in the same manner as in Example 1 except that dimethyldimethoxysilane was 15.0 parts, isopropyl alcohol was 73 parts, and propylene glycol monomethyl ether was 9 parts. evaluated. Table 1 shows the results.

[0015]

[Table 1]

As can be seen from the results shown in Table 1, the examples showed good appearance, initial contact angle and drop inclination angle, while
In Comparative Example 1, the falling inclination angle was insufficient, and in Comparative Example 2
The appearance was poor due to uneven coating.

Claims (2)

[Claims] (A) General formula CF ₃ (CF ₂ ) _m (CH ₂ ) _n SiR _p X _3-p (1) (wherein R is a substituted or unsubstituted monovalent hydrocarbon group,
X is a hydrolyzable group, m is an integer of 0-10, n is an integer of 2-10, and p is an integer of 0-2)
10.0% by weight (B) General formula R ¹ _q SiY _4-q (2) (wherein R ¹ is the same or different unsubstituted monovalent hydrocarbon group, Y is a hydrolyzable group, and q is 1 to Represents the integer of 3)
A water repellent composition containing 0.05 to 10.0% by weight (C) hydrolysis catalyst 0.001 to 10.0% by weight (D) 2.0 to 99.8% by weight organic solvent. 2. The water repellent composition according to claim 1, wherein the organic solvent of the component (D) is alcohol.