JPH07305053A - Water repellent composition - Google Patents

Abstract

PURPOSE:To obtain a water repellent composition which contains a polyorganosiloxane bearing hydrolyzable groups, a metal alkoxide and an alcohol in a specific proportion and can be applied to the surfaces of, for example, clothing and rainwares because it is high in safety, cold-curable and excellent in water repellency. CONSTITUTION:This composition comprises (A) 1.0 pt.wt. of a polyorgano- siloxane bearing at least one of hydrolyzable group (preferably, methoxy or ethoxy group) (preferably it is linear, for example, polydimethylsiloxane, polydimethyl-polydiphenyl-siloxane), (B) 0.1-10 pts.wt., preferably 0.3-1.0 pt.wt. of a metal alkoxide (preferably a titan compound) or its partially hydrolytic condensate, (C) 10-1,000 pts.wt., preferably 20-100 pts.wt. of an alcohol (preferably ethanol).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a water repellent composition, and more particularly to a silicone water repellent composition capable of imparting good water repellency by being applied to the surface of clothes, rain gear and the like and dried.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION AND ITS PROBLEMS Conventionally, a polymer of a polymerizable compound having a perfluoroalkyl group or a perfluoroalkenyl group and an acryl group or a methacryl group is useful as a water repellent agent for fibers. Is known, and is widely applied to clothes, rain gear, etc. as an aerosol type that can be simply diluted with a petroleum solvent such as hexane or petroleum terpene and used with a propellant. However, environmental hygiene issues have been emphasized in recent years, and restrictions on the use of petroleum-based solvents have been taken into consideration, and safer types such as water and alcohols as diluents are desired. On the other hand, methylhydrogenpolysiloxane containing hydrogen atoms bonded to silicon atoms is also widely used as a water repellent agent for fibers, and such a water repellent agent is generally obtained by emulsifying methylhydrogenpolysiloxane with an emulsifier. Although it is used as a treatment liquid and water is used as a diluent (US Pat. Nos. 2,588,366 and 261248).
However, since it is a heat-curing type, it requires heating equipment for processing, and has the drawback of lacking in ease of handling. In addition, a room temperature-curable water repellent composition containing a hydrolyzate of a halogenated silane or a condensate thereof and an organic titanium compound such as titanium alkoxide is known (Japanese Patent Publication No. 30-7568, 31). -3798), the reactivity of the terminal silanol of the hydrolyzate of the halogenated silane or its condensate with the organotitanium compound is very high, so that when these components are blended, partial condensation occurs at the same time. However, when an alcohol having a low affinity for the condensate is used as a solvent, the stability of the composition is significantly deteriorated.

[0003]

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a water repellent composition which exhibits good stability while using a safe solvent, can be cured at room temperature, is easy to handle, and can impart good water repellency.

[0004]

The present inventors have conducted extensive studies in order to achieve the above object, and as a result, by blending a polyorganosiloxane having a hydrolyzable group in the molecule, a metal alkoxide and an alcohol, good characteristics can be obtained. It was found that a water repellent having the above can be obtained, and the present invention has been completed. That is, the present invention relates to (A) 1.0 part by weight of a polyorganosiloxane having at least one hydrolyzable group in the molecule, (B) a metal alkoxide or a partial hydrolyzed condensate thereof.
0.1 to 10 parts by weight (C) A water repellent composition containing 10 to 1000 parts by weight of alcohol.

The present invention will be described in detail below. In the component (A), a polyorganosiloxane having at least one hydrolyzable group in the molecule, the hydrolyzable group includes an alkoxy group, an aminoxy group, a ketoxime group, an acetoxy group, an amide group, an alkenyloxy group and the like. Illustrated,
An alkoxy group is preferable, and a methoxy group and an ethoxy group are particularly preferable, because the by-product generated during the curing reaction has little odor and the curability is good. These hydrolyzable groups are contained in the main chain and / or the side chains of the polyorganosiloxane, but it is preferable that they are contained at the terminals because the curability of the resulting composition is good. As other substituents of polyorganosiloxane, a methyl group,
Ethyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group, alkyl group such as hexadecyl group, cyclohexyl group, cycloalkyl group such as cyclooctyl group, phenyl group, aryl group such as tolyl group, vinyl group, Alkenyl group such as allyl group, halogen-substituted hydrocarbon group such as 3,3,3-trifluoropropyl group, γ-aminopropyl group, aminoalkyl group such as N- (β-aminoethyl) -γ-aminopropyl group Is exemplified. Among these, since it shows good water repellency, an alkyl group,
An aryl group is preferable, and a methyl group and a phenyl group are particularly preferable. In the present invention, by using a polyorganosiloxane having a branched structure as the component (A), the strength of the resulting water-repellent film can be increased. In addition to lowering, the water-repellent film becomes harder, so the texture becomes harder when used for fibers and the like. Therefore, the polyorganosiloxane of the component (A) preferably has a linear or partially branched structure, which is basically a linear structure. The proportion of the branched structure is preferably 50 mol% or less of the trifunctional siloxane unit with respect to the bifunctional siloxane unit, and particularly preferably a linear structure composed of only the bifunctional siloxane unit. Although the molecular weight is not limited, the solubility in alcohol is good, and the water-repellent film obtained has good characteristics.
The molecular weight is preferably such that the viscosity at 0 ° C. is 5 to 100 cSt, particularly 10 to 80 cSt. From the above, in the present invention, linear polydiorganosiloxane having both ends blocked with alkoxy groups is preferable, and polydimethylsiloxane and polydimethyl-polydiphenylsiloxane copolymer are particularly preferable.

As the metal alkoxide of the component (B), metal alkoxides such as silicon-based, titanium-based, aluminum-based, zirconium-based are preferably used, and tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, Tetramethoxy titanium, tetraethoxy titanium, tetraisopropoxy titanium, tetrabutoxy titanium, trimethoxy aluminum, triethoxy aluminum, triisopropoxy aluminum, tri-tert-butoxy aluminum, tetramethoxy zirconium, tetraethoxy zirconium, tetraisopropoxy zirconium, Tetrabutoxy zirconium etc. are illustrated. From the viewpoint of good curability of the composition, alkoxides that do not contain an alkyl group or an allyl group directly linked to each metal, such as tetraalkoxysilane, tetraalkoxytitanium, trialkoxyaluminum, and tetraalkoxyzirconium are preferable. (B)
The component may be a partial hydrolysis-condensation product of these metal alkoxides, or a mixture thereof.
It may be a mixture of more than one kind of metal alkoxide or its partial hydrolysis-condensation product. As the type of metal alkoxide, it is preferable to use titanium-based or zirconium-based, particularly titanium-based, because the composition has good curability.
The amount of component (B) is the same as the polyorganosiloxane of component (A).
It is 0.1 to 10 parts by weight with respect to 1.0 part by weight. If the amount is less than 0.1 part by weight, the curability of the composition is insufficient, and
If the amount is more than the amount by weight, the storage stability of the composition decreases, which is not preferable. Preferably 0.2 to 5.0 parts by weight, especially 0.3 to 1.
0 parts by weight.

The alcohol as the component (C) includes methanol, ethanol, isopropanol, butanol, etc.
Or a mixture of these is exemplified, and with appropriate volatility,
A boiling point of 60 to 200 ° C, particularly 64 to 150 ° C is preferably used because good workability can be obtained. Among them, ethanol and isopropanol, particularly ethanol, are preferable because of good compatibility with the component (A). . The amount of component (C) is
The composition has a good pot life, can be subjected to a uniform water-repellent treatment, and a water-repellent film having good properties can be obtained, so that 10 to 1000 parts by weight, preferably 1.0 to 10 parts by weight of the component (A), is preferable. 15 to 500 parts by weight, particularly preferably 20 to 100 parts by weight, are used.

The water repellent composition of the present invention comprises organic components such as tin, zinc, lead and cobalt which are conventionally known as catalysts for condensation reaction, as long as they do not impair the characteristics of the present invention other than the components (A) to (C). Colorants such as metal compounds, dyes and pigments, mica, silica,
Fine powder such as silicone resin powder, silicone rubber powder, polyethylene powder, conventionally known antistatic agent, softening agent,
You may use together other additives, such as a wrinkle-proof agent, a heat resistance agent, and a flame retardant.

The water repellent of the present invention can be obtained by mixing the respective components to form a uniform composition.
A propellant such as nitrogen gas or carbon dioxide gas may be added to form an aerosol for use. This usage method can spray the target object such as clothing, rain gear, ski wear, etc. in a mist form, so that alcohol can be volatilized in a short time, and the water repellent effect can be promptly exhibited, and it is easy to apply evenly. Therefore, it is particularly preferable. Alternatively, it can be treated by brush coating, a roller method, a dipping method or the like, and can impart good water repellency to an object.

[0010]

The water repellent composition of the present invention is suitable for clothing, rainwear,
In addition to ski wear, it can also be applied to wood, stone, metal, plastic, glass, ceramics, rubber, etc. for buildings, furniture, automobiles, fences, fences, etc. By drying at room temperature, it is excellent at the same time as alcohol volatilizes. Water repellency can be imparted. Further, for example, in the case of targeting a fiber or the like, it also has the effect of improving the feel and the appearance, such as being able to impart the flexibility and the bathochromic effect to the fiber at the same time.

[0011]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples, “part” means “part by weight”, “%” means “% by weight”, and the viscosity means a value at 25 ° C. The following components were used in this example. (A) Component polyorganosiloxane A-1: Polydimethylsiloxane with both ends methoxy groups having a viscosity of 10 cSt A-2: Polydimethylsiloxane with both ends methoxy groups having a viscosity of 15 cSt A-3: Both ends with a viscosity of 30 cSt Isopropoxy group-blocked polydimethylsiloxane A-4: Both ends ethoxy group-blocked polydimethylsiloxane-poly-γ-aminopropylmethylsiloxane copolymer with a viscosity of 70 cSt ^{* 1)} A-5: Both-end methoxy group with a viscosity of 30 cSt Blocked polydimethylsiloxane-polydiphenylsiloxane copolymer ^{* 2)} a-1: Polydimethylsiloxane blocked with hydroxyl groups at both ends with a viscosity of 20 cSt a-2: Polydimethylsiloxane blocked with trimethylsilyl groups at both ends with a viscosity of 20 cSt a-3: Polymethylsilsesquioxane with viscosity of 25 cSt * 1): The content of γ-aminopropyl groups in all organic groups is 3
Mol% * 2): Content of phenyl groups in all organic groups is 20 mol% (B) Component metal alkoxide B-1: Partial condensate of tetrabutoxytitanium B-2: Tetraisopropoxytitanium Examples 1 to 1 11, Comparative Examples 1 to 5 The above-mentioned polyorganosiloxane, metal alkoxide and ethanol were mixed in the ratio shown in Table 1 to obtain a water repellent agent. A black cotton cloth and a Tetoron-cotton blended cloth were treated with the obtained water repellent, and the water repellency, appearance (color) and texture were evaluated. The results are shown in Table 3. The treatment method, water repellency, appearance, and texture evaluation method are as described below. 1) Treatment Method A test cloth (20 × 20 cm) was dipped in a water repellent, squeezed with a mangle (squeezing rate: 50%), dried at room temperature for 10 minutes, and treated. 2) Water repellency test The water repellency of the obtained treated cloth was evaluated by the spray method of JIS L 1092. The water repellency was judged by the evaluation criteria (Table 2) based on the test method. 3) Appearance (Tint) The appearance of the obtained treated cloth was visually observed, and the presence or absence of the bathochromic effect was determined as follows. ◯: Color tone deeper than untreated cloth Δ: Color tone similar to untreated cloth 4) Texture Using the obtained treated cloth, the texture was judged by five panelists as follows. ○: Softer texture than untreated cloth △: Similar texture to untreated cloth ×: Harder texture than untreated cloth

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

As shown in Table 3, the water repellent composition of the present invention can impart excellent water repellency to an object only by being applied and then dried at room temperature, and when used in a fiber. It can be seen that can be further imparted with flexibility (texture) and bathochromic effect (hue).

Claims (5)

[Claims] 1. (A) 1.0 part by weight of a polyorganosiloxane having at least one hydrolyzable group in the molecule (B) a metal alkoxide or a partially hydrolyzed condensate thereof.
0.1 to 10 parts by weight (C) A water repellent composition containing 10 to 1000 parts by weight of alcohol. 2. The water repellent composition according to claim 1, wherein the polyorganosiloxane (A) is a polyorganosiloxane having both ends blocked with alkoxy groups. 3. The water repellent composition according to claim 1, wherein the metal alkoxide (B) is a titanium alkoxide. 4. The water repellent composition according to claim 1, wherein the alcohol (C) is ethanol. 5. The water repellent composition according to claim 1, wherein the polyorganosiloxane (A) has a viscosity at 25 ° C. of 5 to 100 cSt.