JP2704346B2 - Oil-in-water emulsion composition for paintable release agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emulsifying composition for a release agent used for releasing an inner wall of a mold or the like, and more particularly to an oil-in-water (O / W) emulsion composition for a paintable releasing agent. About things.

[0002]

2. Description of the Related Art Hitherto, diorganopolysiloxanes have been used alone or in admixture with other components as mold release agents for molding metal, rubber or plastic molded articles. However, when a diorganopolysiloxane (for example, dimethylpolysiloxane or methylphenylpolysiloxane) is used as a mold release agent such as a mold, the diorganopolysiloxane adheres to the surface of the molded article released from the mold. When a molded article is painted or adhered, there is a drawback that the paint is repelled or adhesion failure occurs. .

In order to solve the above-mentioned drawbacks, the number of carbon atoms is 8
Diorganopolysiloxane substituted with a long-chain alkyl group of from 20 to 20 (Japanese Patent Publication No. 40-9618), a long-chain alkyl group having 7 or more carbon atoms and a 2-phenylpropyl group, or 2
Diorganopolysiloxane having an aralkyl group selected from -phenylethyl group as a substituent (Japanese Patent Publication No.
No.-10057) or a diorganopolysiloxane having a long-chain alkyl group or phenylalkyl group having 7 to 15 carbon atoms as a substituent and a silicone resin (generally MQ
(Referred to as JP-B-3-116)
No. 06) has been proposed as a composition for a release agent, and has achieved good results.

However, since these release agent compositions have high viscosity and must be diluted with an organic solvent when used, they are inferior in dilution workability and mixing workability (hereinafter simply referred to as dilution workability). There were drawbacks. On the other hand, an aqueous emulsion using an organic silane having an alkyl group having 8 to 30 carbon atoms as a substituent has been proposed as a composition for a release agent for metal casting (Japanese Patent Publication No. 47-25567).
No. 2), the aqueous emulsion has a drawback that it is poor in dilution stability, storage stability, or mechanical stability (simply referred to as stability).

[0005] Further, a composition for a mold release agent obtained by adding sodium polyoxyethylene alkylphenyl ether sulfate to an aqueous emulsion of a diorganopolysiloxane having a monovalent hydrocarbon group having 1 to 18 carbon atoms as a substituent. Has also been proposed. However, in this case, the aqueous emulsion using dimethylpolysiloxane is stable, whereas the aqueous emulsion using diorganopolysiloxane containing a large amount of long-chain alkyl groups in the structure is stable. There was a drawback that the property was poor.

[0006]

The inventors of the present invention have conducted intensive studies to solve the above-mentioned drawbacks, and as a result, used an emulsified composition containing a specific organopolysiloxane as a mold release agent or a raw material thereof. In this case, it was found that good results were obtained, and the present invention was reached.

Accordingly, a first object of the present invention is to provide a paintable composition for a release agent which does not adversely affect the paintability and adhesiveness of a molded article. A second object of the present invention is to provide an oil-in-water, paintable emulsion composition excellent in workability and stability even when a high concentration of diorganopolysiloxane is contained.

[0008]

The above objects of the present invention have been attained by an oil-in-water emulsion composition for paintable release agents comprising the following components (a) to (d). Component (a): a viscosity at 25 ° C of 10 to 100,00
10 to 90% by weight of a diorganopolysiloxane represented by the following formula 1, which is 0 centistokes:

Embedded image In the formula, R ¹ represents one or more organic groups selected from monovalent saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms, R ² is saturated or 8 to 20 carbon atoms One or more organic groups selected from unsaturated monovalent hydrocarbon groups, a and b are 2 or 3, m is an integer of 5 to 1,000,
n is an integer of 0 to 500 and m / (m + n)> 0.5.

Component (b): an HLB value (weighted average HLB value in the case of two or more types) of 10 to 18, and at least one polyoxyethylene higher alcohol ether 1 to 50 represented by the following formula (2): weight%:

Embedded image ^{_{R 3 O (C 2 H 4}} O) p H formula, R ³ is a monovalent saturated or unsaturated hydrocarbon group having 12 to 20 carbon atoms, p is 1 to 100 integer It is.

Component (c): 0.01 to 5 polyoxyethylene higher alcohol ether sulfate represented by the following formula (3):
weight%:

Embedded image R ⁴ O (C ₂ H ₄ O) _q SO ₃ M wherein R ⁴ is a saturated or unsaturated monovalent hydrocarbon group having 12 to 20 carbon atoms, and q is an integer of 1 to 100. , And M are alkali metal or ammonium groups. (D) Component: water (remainder).

As the organic group for R ¹ , for example, a methyl group,
Saturated monovalent carbonization such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, cyclohexyl, etc. Examples thereof include a hydrogen group or an unsaturated monovalent hydrocarbon group such as a vinyl group, an allyl group, and a phenyl group. Among them, it is particularly preferable that a methyl group is 90 mol% or more.

Specific examples of the organic group represented by R ² include n-octyl, 2-ethylhexyl, n-decyl, isodecyl, n-dodecyl, n-tetradecyl, n-hexadecyl, and n-octadecyl. A saturated monovalent hydrocarbon group such as a group or an oleyl group, a 2-phenylethyl group,
Examples thereof include unsaturated monovalent hydrocarbon groups such as a 2-phenylpropyl group, and among them, an n-dodecyl group and an n-tetradecyl group are preferable.

The diorganopolysiloxane of component (a) preferably has a viscosity at 25 ° C. of 10 to 100,000 centistokes (hereinafter cs).
In particular, it is preferably in the range of 100 to 10,000 cs. If the viscosity is lower than 10 cs, the releasability becomes insufficient. If the viscosity is higher than 100,000 cs, the emulsification becomes difficult, and the extensibility to a mold or the like is reduced, so that the releasability is insufficient.

The average degree of polymerization of the structural units of the diorganopolysiloxane represented by the chemical formula 4 is preferably such that m is 5 to 1,000, n is 0 to 500, and m / (m + n)> 0.5. In particular, m / (m + n) is preferably 0.7 or more. If m / (m + n) is less than 0.5, the coating properties and adhesion of the molded article will be reduced.

In the polyoxyethylene higher alcohol ether represented by the chemical formula (5) as the component (b), specific examples of R ³ in the chemical formula (5) include a dodecyl group, a tridecyl group,
Saturated 1 such as tetradecyl, cetyl, stearyl, etc.
Examples thereof include a monovalent hydrocarbon group and an unsaturated monovalent hydrocarbon group such as an oleyl group. Of these, a tridecyl group is particularly preferable. One or more polyoxyethylene higher alcohols may be used.

HL of polyoxyethylene higher alcohol
The B value (hydrophile-lipophilic balance) (weighted average in the case of a mixture of two or more types) is preferably set to 10 to 18, and particularly preferably 12 to 15. H
If the LB value is smaller than 10 or larger than 18, the stability of the obtained emulsion composition is reduced. Also, p in Chemical Formula 5 is preferably an integer in the range of 1 to 100, but from the viewpoint of stably emulsifying and dispersing the diorganopolysiloxane as the component (a) in water, it is 5 to 50. Is particularly preferred.

(C) In the polyoxyethylene higher alcohol ether sulfate represented by Chemical Formula 6 as a component,
Specific examples of R ⁴ include a saturated monovalent hydrocarbon group such as a dodecyl group, a tridecyl group, a tetradecyl group, a cetyl group, and a stearyl group, and an unsaturated monovalent hydrocarbon group such as an oleyl group. However, among these, a tridecyl group is particularly preferred. In addition, q in Chemical Formula 6 is preferably an integer in the range of 1 to 100, but from the viewpoint of improving the emulsifying dispersibility of the component (a), diorganopolysiloxane in water, is particularly preferably 1 to 100. Desirably, it is an integer of 10.

Next, the amounts of the components (a) to (c) will be described. The component (a) needs to be 10 to 90% by weight, preferably 30 to 70% by weight, and 40 to 70% by weight.
It is particularly preferred to be 60% by weight. If the content is 10% by weight or less, the capacity of the emulsified composition becomes too large, which is economically disadvantageous in terms of transportation and the like, and if it is 90% by weight or more, the emulsified composition has a high viscosity and becomes difficult to handle.

The component (b) needs to be 1 to 50% by weight, preferably 2 to 10% by weight, particularly preferably 3 to 5% by weight. 1% by weight
If it is less than 50%, the stability of the emulsified composition is reduced, and
If the above is set, the viscosity of the emulsified composition becomes high and handling becomes difficult.

The component (c) needs to be 0.01 to 5% by weight, preferably 0.05 to 1% by weight, and more preferably 0.1 to 0.5% by weight. Is particularly preferred. When the content is 0.01% by weight or less, the viscosity of the emulsified composition cannot be sufficiently reduced, and when the content is 5% by weight or more, the stability of the emulsified composition decreases. By adding water as the component (d) to the above components (a) to (c), an oil-in-water (O / W) emulsion composition (hereinafter simply referred to as O / W) for a paintable release agent of the present invention is obtained. Emulsified composition).

The chemical formula 4 as the component (A) used in the present invention
The diorganopolysiloxane represented by is generally easily produced by subjecting a known alkyl hydrogen polysiloxane and a vinyl group-containing organic compound to a hydrosilylation reaction in the presence of a platinum catalyst (US Pat. 3,885,984).

The O / W type emulsified composition of the present invention comprises a diorganopolysiloxane as a component (a), a polyoxyethylene higher alcohol ether as a component (b) as an emulsifier, and a (c) component. A polyoxyethylene alkyl ether sulfate is added, and the mixture is easily emulsified and dispersed in water using a high-shear emulsifying and dispersing machine such as a homomixer, a colloid mill, and a high-pressure homogenizer. The emulsifying and dispersing machine to be used is not particularly limited, and an appropriate machine may be selected according to the viscosity of the diorganopolysiloxane to be used.

Further, only the polyoxyethylene higher alcohol ether of the component (b) is added as an emulsifier to the diorganopolysiloxane of the component (a), and the resulting mixture is emulsified and dispersed in water to form an emulsion. The O / W type emulsified composition of the present invention can also be produced by adding and mixing the polyoxyethylene higher alcohol ether sulfate (C) as the other emulsifier. The O / W emulsion composition of the present invention may further contain a pH buffer, a preservative,
A rust preventive, a penetrant and the like may be appropriately added and blended.

The O / W emulsion composition of the present invention can be used as a paint release agent as it is or by diluting it with water and applying it to a mold. , Talc, etc., inorganic compound powders, organic resin powders such as fluororesin, nylon resin, polycarbonate resin, silicone resin, and other release agents such as various natural waxes, synthetic waxes, higher fatty acids, higher fatty acid esters and higher fatty acid salts You may mix | blend a property imparting agent.

[0025]

The O / W type emulsified composition of the present invention, when used as a paint release agent, does not impair the coatability and adhesiveness of a molded product released from a mold or the like. ,
Even when the diorganopolysiloxane is contained at a high concentration, the viscosity is low, so it is excellent in dilution workability etc. and also excellent in stability, so as it is as a paintable release agent,
Alternatively, it can be widely used as a raw material.

[0026]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 In a 1-liter plastic beaker, as a diorganopolysiloxane of the component (a), a diorganopolysiloxane having a viscosity of 920 cs at 25 ° C. represented by the following formula (7) was prepared. 500 g, polyoxyethylene tridecyl ether having an HLB of 10.5 (ethylene oxide 5 mol adduct) (the component (ii) -1) as the polyoxyethylene higher alcohol ether of the component (ii) , And polyoxyethylene tridecyl ether having an HLB of 16.3 (ethylene oxide 20 mol adduct)
22 g (weighted average HLB = 1)
3.1) 1.5g of sodium polyoxyethylene tridecyl ether sulfate (ethylene oxide 5 mol adduct) (the component (c) -1) is charged as the polyoxyethylene higher alcohol ether sulfate of the component (c). ,
After homogenous mixing using a homomixer, 450 g of water was gradually added and dispersed to obtain a dispersion. Then 3
The dispersion obtained at a pressure of 00 Kg / cm ² was passed through a high-pressure homogenizer once to obtain an emulsified composition.

[0028]

Embedded image The following tests were performed on the obtained emulsion composition, and the results of evaluation were as shown in Table 1. (1) Viscosity of Emulsion Composition The viscosity of the composition at 25 ° C. was measured with a BM-type rotational viscometer.

(2) Storage stability test 100 g of the emulsified composition was placed in a 100-ml glass bottle, capped, allowed to stand at 45 ° C. for 7 days, and the appearance was visually observed and evaluated according to the following criteria. ○: No separation (no oil floating on liquid surface) △: No separation (oil floating on liquid surface) ×: Separation

(3) Dilution stability test After putting 2 g of the emulsified composition in a 100 ml glass bottle,
After diluting with 98 g of water and closing the lid, and allowed to stand at 45 ° C. for 7 days, the appearance was visually observed and evaluated according to the following criteria. ○: No separation (no oil floating on the liquid surface) ×: Separation

(4) Mechanical Stability Test After putting 20 g of the emulsified composition in a 1-liter container, 980 g of water was added.
And maintained at 45 ° C., and 1.5 l /
After circulating for 48 hours at a flow rate of 1 minute and standing still for 1 hour, the appearance was visually observed and evaluated according to the following criteria. ○: No separation ×: Separation

(5) Paintability test A 2% aqueous solution of the emulsified composition was gauze-coated on an aluminum plate (50 mm).
X 150 mm), air-dried, and then heat-treated in a dryer at 200 ° C for 30 minutes. After allowing to cool to room temperature, magic ink was applied and the state of repelling was visually observed and evaluated according to the following criteria. : 0 to 50 repelling points ×: 50 or more repelling points

Embodiments 2-5. An emulsion composition was prepared according to the formulation shown in Table 1 in the same manner as in Example 1, and a test was conducted in the same manner as in Example 1. The results of the evaluation are as shown in Table 1.

[Table 1]

Comparative Examples 1-4. An emulsion composition was prepared according to the formulation shown in Table 2 in the same manner as in Example 1, and a test was conducted in the same manner as in Example 1. The results of the evaluation are as shown in Table 2. The component (a) -2 in Table 2 is an organopolysiloxane having a viscosity of 560 cs at 25 ° C. represented by the following chemical formula 8.

Embedded image

[Table 2] The above results indicate that the emulsified composition of the present invention is easy to handle due to its low viscosity, is excellent in storage stability, dilution stability and mechanical stability, and has good applicability (paintable) when used as a release agent. ) Is also good.

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication location C08L 71/02 C08J 3/03 CFH // C09D 183/04 (72) Inventor Kohei Hasegawa Matsuida-machi, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Industry Co., Ltd. Silicone Electronic Materials Technology Laboratory (72) Inventor Naohiro Takahashi 1-chome, Matsuida-cho, Usui-gun, Gunma Prefecture Shin-Etsu Chemical Co., Ltd. Silicone Electronic Material Technology Research In-house (72) Inventor Satoshi Kuwata 1-10 Hitomi, Matsuida-machi, Usui-gun, Gunma Prefecture Silicone Electronic Materials Technology Laboratory, Shin-Etsu Chemical Co., Ltd.

Claims (1)

(57) [Claims] An oil-in-water emulsion composition for a paintable release agent comprising the following components (A) to (D): Component (A) having a viscosity of 10 to 100,00 at 25 ° C.
0-centistokes, 10-90% by weight of a diorganopolysiloxane represented by the following formula: In the formula, R ¹ represents one or more organic groups selected from monovalent saturated or unsaturated hydrocarbon group having 1 to 6 carbon atoms, R ² is saturated or 8 to 20 carbon atoms One or more organic groups selected from unsaturated monovalent hydrocarbon groups, a and b are 2 or 3, m is an integer of 5 to 1,000,
n is an integer of 0 to 500 and m / (m + n)>0.5; (b) component: HLB value (weighted average HL for two or more types)
B value) is 10 to 18, and 1 to 50% by weight of at least one polyoxyethylene higher alcohol ether represented by the following chemical formula 2: R ³ O (C ₂ H ₄ O) _pH In the formula, R ³ is a saturated or unsaturated monovalent hydrocarbon group having 12 to 20 carbon atoms, and p is an integer of 1 to 100; Oxyethylene higher alcohol ether sulfate 0.01 to 5% by weight: R ⁴ O (C ₂ H ₄ O) _{qSO 3} M In the formula, R ⁴ is a saturated or unsaturated unsaturated compound having 12 to 20 carbon atoms. Is a monovalent hydrocarbon group, q is an integer of 1 to 100, and M is an alkali metal or ammonium group; (d) component: water (remainder).