JP2003171649A - Coating agent composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating agent composition excellent in, especially, storage stability, dilution stability, and mechanical stability, capable of being uniformly applied to moldings of such as rubbers and plastics, and useful as an inhibitor against the tack among such moldings. <P>SOLUTION: The coating agent composition comprises a silicone emulsion comprising (A) a polydiorganosiloxane having a viscosity of 50-100,000 mPas at 25°C, (B) an 8-12C monohydric alcohol, (C) a polyoxyethylene alkyl ether, (D) an alkylamine oxide compound, (E) a polyoxyethylene alkyl ether acid salt, and (F) water. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is particularly directed to storage stability,
The present invention relates to a coating agent composition which is excellent in dilution stability and mechanical stability and can be uniformly applied to molded articles such as rubber and plastics, and particularly to a coating agent composition which is useful as an anti-sticking agent for these molded articles. Furthermore, the coating agent composition of the present invention is also useful as a release agent when molding these molded articles.

[0002]

2. Description of the Related Art Conventionally, a release agent at the time of molding rubber and synthetic resin, and fixing and sticking between molded products and their surroundings,
As an anti-sticking agent to prevent clinging, and as a lubricant to prevent catching when attaching products to each other and their surroundings when feeding, separating, taking out products,
Polyorganosiloxane is used. Generally, polysiloxane is used because it has a high viscosity, so it is diluted as a solvent or emulsion, but when diluted with a solvent, solvent cracks in the base material and safety in the coating process become a problem. Therefore, a water-based dimethyl silicone emulsion or the like has been used (JP-A-57-111134, JP-A-60-179211).
JP-A-62-275711, JP-A-62-275711
-3908, JP-A-8-188744, and JP-B-63-62538).

However, the conventionally proposed coating agent, when used as a release agent, is
There is a problem that repelling or liquid leakage occurs on the surface of the water-repellent mold and the unvulcanized rubber material, resulting in uncoated portions or coating spots, which causes deterioration of mold release property and deterioration of product appearance. In addition, even when used as an anti-sticking agent, the surface of the molded product is extremely hydrophobic, resulting in uncoated parts and coating spots, resulting in poor appearance when molded products and sticking. There was a problem.

Further, since these coating agents are used by being recycled and recycled in view of their economical efficiency, they are required to have dilution stability and stability against strong mechanical shearing force. As a means for improving such a problem, for example, in Japanese Patent Publication No. 53-13501, a proposal for improving mechanical stability by using sodium polyoxyethylene alkylphenyl ether sulfate is disclosed in JP-A-4-2856.
In Japanese Patent Laid-Open No. 65, there is a proposal to improve mechanical stability by combining a polyoxyethylene alkyl ether and a polyoxyethylene alkyl ether sulfate, but the stability is still insufficient.

[0005]

The object of the present invention is particularly excellent in storage stability, dilution stability and mechanical stability, and can be uniformly applied to molded articles such as rubber and plastic. It is intended to provide a coating composition which is useful as an anti-sticking agent.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, have found that polydiorganosiloxane having a viscosity at 25 ° C. of 50 to 100,000 mPa · s and a carbon number of 8 to 12 are obtained. It is extremely effective to use a silicone emulsion composed of a monohydric alcohol, a polyoxyethylene alkyl ether, an alkylamine oxide compound, a polyoxyethylene alkyl ether acid salt and water, which is excellent in solving the above problems. It was found that a coating agent having the above-mentioned performance can be obtained, and the present invention has been completed.

That is, according to the present invention, (A) the viscosity at 25 ° C. is 50 to 100,000 mPas.
S polydiorganosiloxane; 100 parts by weight (B) monohydric alcohol having 8 to 12 carbon atoms; 0.1
-10 parts by weight (C) polyoxyethylene alkyl ether; 1-50 parts by weight (D) alkylamine oxide compound; 0.1-10
Parts by weight (E) polyoxyethylene alkyl ether acid salt; 0.0
1 to 10 parts by weight (F) water; a coating agent composition comprising a silicone emulsion in an amount such that the content of the silicone as the component (A) in the composition is 0.5 to 60% by weight.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The polydiorganosiloxane of the component (A) used in the present invention is a component that exerts a releasing action and an anti-sticking action. The viscosity of such polydiorganosiloxane is 50 to 100,000 mPa · s at 25 ° C., and preferably 100 to 10,000 mPa · s. If it is less than 50 mPa · s, the effect of preventing mold release and sticking is not sufficient, and if it exceeds 100,000 mPa · s, the molded product tends to stick and has a sticky feeling.

The polydiorganosiloxane used is 2
The viscosity at 5 ° C. may be within the above range, and one kind thereof may be used alone or two or more kinds may be mixed and used.

The polydiorganosiloxane used is preferably a linear polydiorganosiloxane, but it may have a partial branch or network structure. The terminal functional group of the polydiorganosiloxane is not particularly limited, but preferably a methyl group, a hydroxyl group,
Alternatively, it is preferably a methoxy group.

The organic group bonded to the silicon atom in the polydiorganosiloxane includes an alkyl group such as methyl group, ethyl group, propyl group, butyl group and hexyl group; alkenyl group such as vinyl group and propenyl group; phenyl group Examples thereof include an aryl group such as; and an aralkyl group such as a phenethyl group; and those in which a part of hydrogen atoms of these hydrocarbon groups are substituted with a halogen atom, a nitrile group, or the like. A methyl group is preferred.

The component (B) is one of the characteristic components of the present invention, and it prevents the repelling of the composition and the occurrence of liquid leakage. The monohydric alcohol as the component (B) has 8 carbon atoms.
It is necessary that the number of carbon atoms is from 12 to 12, and those having 12 carbon atoms are particularly preferable. The carbon chain may be linear or partially branched. Carbon number less than 8 and 12
Alcohols over 10 do not show a sufficient effect, and if alcohols over 12 carbons are used, a stable emulsion composition cannot be obtained.

The amount of component (B) compounded is 0.1 to 10 parts by weight per 100 parts by weight of component (A). This is because if it is less than 0.1 part by weight, the effect of preventing repelling and liquid leakage is not obtained, and if it exceeds 10 parts by weight, the coating property is deteriorated and a stable emulsion composition cannot be obtained.

The component (C), a polyoxyethylene alkyl ether, is used as an emulsifying agent for silicone emulsions. The alkyl group of the component (C) represents a monovalent hydrocarbon group having 8 to 24 carbon atoms. As a specific example, an ethylhexyl group,
Examples thereof include a nonyl group, a decyl group, a lauryl group, a tetradecyl group, a cetyl group, and a stearyl group, but from the viewpoint of the viscosity decreasing effect when the silicone content is high, a carbon number of 8 to 10 is preferable. The number of added moles of ethylene oxide is not particularly limited as long as it is 1 or more, but 2 to 20 is preferable from the viewpoint of emulsifying and dispersing silicone in water. The component (C) can be used as a mixture of two or more kinds, and the compounding amount is 1 to 5 with respect to 100 parts by weight of the component (A).
It is 0 part by weight, preferably 3 to 30 parts by weight. If it is less than 1 part by weight, an emulsion having good emulsion dispersion stability cannot be obtained, and if it exceeds 50 parts by weight, a large amount remains as a non-volatile component, which impairs the properties of silicone.

The alkylamine oxide compound as the component (D) and the polyoxyethylene alkyl ether acid salt as the component (E) are also characteristic components of the present invention, and are components that improve mechanical stability. Examples of the alkylamine oxide-based compound as the component (D) include dimethylalkylamine oxide and diethanolamine oxide, and the alkyl groups thereof further include a decyl group, a lauryl group, a myristyl group, and coconut (natural oil-and-oil modifying group such as coconut oil). Are exemplified. Further, the compounding amount of the component (D) is 0.1 to 10 parts by weight with respect to the component (A). This is because if the amount is less than 0.1 part by weight, the effect is not exhibited, and if it exceeds 10 parts by weight, the coating property is deteriorated. The time of addition may be either from the beginning of the emulsion preparation or from the latter.

The alkyl group of the polyoxyethylene alkyl ether acid salt as the component (E) preferably has 8 to 22 carbon atoms. Examples of acid salts include alkali metal sulfates, ammonium sulfates, alkali metal acetates and ammonium acetates. Examples of the alkali metal include, but are not limited to, sodium, potassium and mixtures thereof. Examples of the ether group include a polyoxyethylene group, and the number of added moles thereof is not particularly limited as long as it is 1 or more, but from the viewpoint of a viscosity decreasing effect and an improvement in mechanical stability when the content of silicone is large, It is preferably 1 to 10.

The amount of component (E) compounded is 0.01 to 10 parts by weight per 100 parts by weight of component (A). If it is less than 0.01 part by weight, no effect is exhibited, and if it exceeds 10 parts by weight, the dilution stability of the emulsion is decreased. The time of addition may be either from the beginning of the emulsion preparation or from the latter.

The amount of component (F), water, is not particularly limited, but the content of silicone (component (A) in the composition is 0.5 to 60% by weight) for ease of coating. Such an amount is preferable. Silicone content is 0.
If it is less than 5% by weight, coating efficiency and coatability are not sufficient, and if it exceeds 60% by weight, thin film coatability and handling are inconvenient.

The coating agent composition of the present invention may optionally contain an antifoaming agent, a thickener, a pigment, an inorganic powder, a surfactant and the like, if necessary. The coating method using the coating agent composition of the present invention thus prepared is applied at room temperature by applying it to the mold or unvulcanized rubber surface by a method such as brush coating, roll coating, spray coating, knife coating, and dip coating. Alternatively, it is dried by heating before use.

The composition of the present invention is useful as a coating agent for rubber and plastics, and is particularly suitable for molding of NBR, butyl rubber, EPDM rubber, SBR, nitrile rubber, acrylic rubber, fluororubber and the like.

[0021]

INDUSTRIAL APPLICABILITY The composition of the present invention is a coating agent composition which is particularly excellent in storage stability, dilution stability and mechanical stability and can be uniformly applied to molded articles such as rubber and plastics. It is useful as an anti-sticking agent for each other and also as a release agent at the time of molding these molded articles.

[0022]

EXAMPLES The present invention will be described below with reference to examples. In the examples and comparative examples, all parts are parts by weight. Example 1 100 parts of polydimethylsiloxane having a viscosity of 1000 mPa · s at 25 ° C., 3 parts of polyoxyethylene decyl ether (ethylene oxide; 3 mol), polyoxydiethylene decyl ether (ethylene oxide;
15 mol) 3 parts, lauryl alcohol 3 parts, lauryl dimethylamine oxide 3 parts, and water 12 parts were added and mixed uniformly, and then emulsified using a colloid mill type emulsifier,
Further, 6 parts of sodium lauryl ether sulfate (ethylene oxide; 2 mol) and 70 parts of water were added and uniformly mixed to obtain an emulsion.

The storage stability of this emulsion was evaluated. In addition, this emulsion is used as a solid content of 10
The coating liquid composition of the present invention was obtained by diluting with water so that the amount of the chemical composition became 100%, and the physical properties were evaluated as follows. In addition, dilution stability and mechanical stability were also evaluated. The results are shown in Table 1. (Physical property evaluation method) As a coating method of the coating composition, after diluting with water to a solid content of 10%, N
BR rubber O-rings (25 mmφ) 10 pieces are applied to a bucket using the dipping method, and the repelling at that time, coating unevenness,
The presence or absence of the afterflow was checked. After that, the liquid was drained by centrifugation and then dried with hot air at 90 ° C., and the appearance (presence of spots, oil spots, overlapping marks) after drying was examined. Examples 2 to 4 Emulsions were obtained and evaluated in the same manner as in Example 1 except that the constituent substances were changed to those shown in Table 1. Comparative Examples 1 to 4 Emulsions were obtained and evaluated in the same manner as in Example 1 except that the constituent substances were changed to those shown in Table 1.

[0024]

[Table 1]

Continued front page    (72) Inventor Naomi Kase             6-2-1 Roppongi, Minato-ku, Tokyo             -Toshiba Silicone Co., Ltd. F-term (reference) 4J038 DF012 DL031 GA02 GA03                       HA156 JA19 JB01 JB03                       JC37 MA08 MA10 NA09 NA10                       NA26 PC07 PC08

Claims (2)

[Claims] 1. (A) The viscosity at 25 ° C. is 50 to 100,
000 mPa · s polydiorganosiloxane; 100
Parts by weight (B) monohydric alcohol having 8 to 12 carbon atoms; 0.1
-10 parts by weight (C) polyoxyethylene alkyl ether; 1-50 parts by weight (D) alkylamine oxide compound; 0.1-10
Parts by weight (E) polyoxyethylene alkyl ether acid salt; 0.0
1 to 10 parts by weight (F) water; a coating agent composition comprising a silicone emulsion in an amount such that the content of the silicone as the component (A) in the composition is 0.5 to 60% by weight. 2. The coating agent composition according to claim 1, wherein the alkyl chain of (C) polyoxyethylene alkyl ether is C8 to C10.