JP3900336B2 - Coating agent composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is particularly excellent in storage stability, dilution stability, and mechanical stability, and is a coating agent composition that can be uniformly applied to molded articles such as rubber and plastic, and particularly useful as an anti-sticking agent between these molded articles. It relates to a composition. Furthermore, the coating agent composition of the present invention is also useful as a mold release agent for molding these molded products.
[0002]
[Prior art]
Conventionally, release agents for molding rubber and synthetic resins, and anti-sticking agents that prevent sticking, sticking and clinging between molded products and their surroundings, and products between products during feed, separation, and removal Polyorganosiloxane is used as a lubricant for preventing catching when attached to the surrounding area. In general, polysiloxane is used as a solvent or emulsion because it has a high viscosity. However, when diluted with a solvent, solvent cracks in the substrate and safety in the coating process become a problem. Therefore, an aqueous dimethyl silicone emulsion or the like has been used (Japanese Patent Laid-Open Nos. 57-111394, 60-179211, 62-275711, and 62-3908). JP-A-8-188744 and JP-B-63-62538).
[0003]
However, when the coating agent proposed in the past is used as a mold release agent, when applied, the surface of the water-repellent mold and the surface of the unvulcanized rubber material may be repelled or liquid-developed. As a result, there have been problems in that the releasability is deteriorated and the appearance of the product is impaired. 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 and sticking. There was a problem.
[0004]
Moreover, since these coating agents are used after being recycled and recycled due to their economical efficiency, they are also required to have dilution stability and stability against a strong mechanical shearing force. As means for improving such a problem, for example, Japanese Patent Publication No. 53-13501 discloses a proposal for improving mechanical stability by using sodium polyoxyethylene alkylphenyl ether sulfate, and Japanese Patent Application Laid-Open No. 4-285665 discloses polyoxyethylene. There have been proposals to improve the mechanical stability by combining alkyl ethers and polyoxyethylene alkyl ether sulfates, but the stability is still insufficient.
[0005]
[Problems to be solved by the invention]
The object of the present invention is, in particular, a coating composition which is excellent in storage stability, dilution stability and mechanical stability and can be uniformly applied to molded products such as rubber and plastic, and is particularly useful as an anti-sticking agent between these molded products. To provide things.
[0006]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above-described object, the present inventors have found that a polydiorganosiloxane having a viscosity at 25 ° C. of 50 to 100,000 mPa · s, a monohydric alcohol having 8 to 12 carbon atoms, and polyoxy It is extremely effective to use a silicone emulsion comprising an ethylene alkyl ether, an alkylamine oxide compound, a polyoxyethylene alkyl etherate and water, and a coating agent having excellent performance in which the above problems are solved can be obtained. As a result, the present invention has been completed.
[0007]
That is, the present invention
(A) Polydiorganosiloxane having a viscosity at 25 ° C. of 50 to 100,000 mPa · s; 100 parts by weight
(B) Monovalent alcohol having 8 to 12 carbon atoms; 0.1 to 10 parts by weight
(C) Polyoxyethylene alkyl ether; 1 to 50 parts by weight
(D) Alkylamine oxide compound; 0.1 to 10 parts by weight
(E) Polyoxyethylene alkyl etherate salt: 0.01 to 10 parts by weight
(F) Water; a coating agent composition comprising a silicone emulsion having an amount of 0.5 to 60% by weight of the silicone content of component (A) in the composition.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail. The polydiorganosiloxane (A) used in the present invention is a component that provides a releasing action and an anti-sticking action. The viscosity of such polydiorganosiloxane is 50 to 100,000 mPa · s, preferably 100 to 10,000 mPa · s at 25 ° C. 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 or feel sticky.
[0009]
The polydiorganosiloxane to be used has only to have a viscosity at 25 ° C. within the above range, and one kind thereof may be used alone, or two or more kinds may be mixed and used.
[0010]
The polydiorganosiloxane used is preferably a linear polydiorganosiloxane, but may have a partial branch or network structure. The terminal functional group of the polydiorganosiloxane is not particularly limited, but is preferably a methyl group, a hydroxyl group, or a methoxy group.
[0011]
The organic group bonded to the silicon atom in the polydiorganosiloxane is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group or a hexyl group; an alkenyl group such as a vinyl group or a propenyl group; Examples include aryl groups; aralkyl groups such as phenethyl groups; and those in which some of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms, nitrile groups, etc. Is preferred.
[0012]
The component (B) is one of the characteristic components of the present invention, and prevents the composition from being flipped or from getting close to the liquid. The (B) component monohydric alcohol needs to have 8 to 12 carbon atoms, and preferably has 12 carbon atoms. The carbon chain may be linear or partially branched. Alcohols having less than 8 and more than 12 carbon atoms do not have a sufficient effect, and when alcohols having more than 12 carbon atoms are used, a stable emulsion composition cannot be obtained.
[0013]
The amount of component (B) is 0.1 to 10 parts by weight per 100 parts by weight of component (A). If the amount is less than 0.1 part by weight, there is no effect of preventing the occurrence of repelling or liquid drip, and if the amount exceeds 10 parts by weight, the coating property is lowered and a stable emulsion composition cannot be obtained.
[0014]
The polyoxyethylene alkyl ether (C) is used as an emulsifier for silicone emulsion. The alkyl group of the component (C) represents a monovalent hydrocarbon group having 8 to 24 carbon atoms. Specific examples include an ethylhexyl group, a nonyl group, a decyl group, a lauryl group, a tetradecyl group, a cetyl group, a stearyl group, and the like. From the viewpoint of the effect of decreasing the viscosity when the silicone content is high, the carbon number is 8 to 10 is preferred. The number of moles of ethylene oxide added 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. (C) 2 or more types of components can also be mixed and used, and the compounding quantity is 1-50 weight part with respect to 100 weight part of (A) component, Preferably it is 3-30 weight part. If the amount is less than 1 part by weight, an emulsion having good emulsification and dispersion stability cannot be obtained. If the amount exceeds 50 parts by weight, a large amount of non-volatile components remain, which inhibits the properties of silicone.
[0015]
The (D) component alkylamine oxide compound and the (E) component polyoxyethylene alkyl etherate are also characteristic components of the present invention, and are components that improve mechanical stability. (D) Component alkylamine oxide compounds include dimethylalkylamine oxide, diethanolamine oxide and the like, and the alkyl groups include decyl group, lauryl group, myristyl group, palm (natural oil-modified group such as coconut oil). Etc. are exemplified. Moreover, the compounding quantity of (D) component is 0.1-10 weight part with respect to (A) component. If the amount is less than 0.1 parts by weight, the effect is not exhibited, and if it exceeds 10 parts by weight, the coating property is deteriorated. Further, the addition time may be added from the beginning or after the emulsion preparation.
[0016]
(E) It is preferable that the alkyl group of the polyoxyethylene alkyl etherate of a component is C8-C22. Examples of acid salts include alkali metal sulfates, ammonium sulfates, alkali metal acetates, and ammonium acetates. Examples of the alkali metal include sodium, potassium, and a mixture thereof, but are not limited thereto. Examples of ether groups include polyoxyethylene groups, and the number of moles added is not particularly limited as long as it is 1 or more. It is preferable to set it as 1-10.
[0017]
(E) The compounding quantity of a component is 0.01-10 weight part with respect to 100 weight part of (A) component. If the amount is less than 0.01 parts by weight, the effect is not exhibited. If the amount exceeds 10 parts by weight, the dilution stability of the emulsion decreases. Further, the addition time may be added from the beginning or after the emulsion preparation.
[0018]
The blending amount of water as component (F) is not particularly limited, but in view of ease of coating, an amount such that the content of silicone as component (A) in the composition is 0.5 to 60% by weight. It is preferable that When the silicone content is less than 0.5% by weight, coating efficiency and coating properties are not sufficient, and when it exceeds 60% by weight, thin film coating properties and handling are inconvenient.
[0019]
In the coating agent composition of the present invention, an antifoaming agent, a thickening agent, a pigment, an inorganic powder, a surfactant, and the like may be appropriately added as necessary. The coating method using the coating composition of the present invention thus prepared is applied to a mold or unvulcanized rubber surface by a method such as brush coating, roll coating, spray coating, knife coating or dip coating. Alternatively, it is used after drying by heating.
[0020]
The composition of the present invention is useful as a coating agent for rubber and plastic, but is particularly suitable for molding of NBR, butyl rubber, EPDM rubber, SBR, nitrile rubber, acrylic rubber, fluororubber, and the like.
[0021]
【The invention's effect】
The composition of the present invention is a coating agent composition that is particularly excellent in storage stability, dilution stability and mechanical stability and can be uniformly applied to molded articles such as rubber and plastic, and in particular, an anti-sticking agent between these molded articles. It is also useful as a mold release agent for molding these molded products.
[0022]
【Example】
Hereinafter, the present invention will be described by way of examples. In Examples and Comparative Examples, all parts represent parts by weight.
Example 1
100 parts of polydimethylsiloxane having a viscosity at 25 ° C. of 1000 mPa · s, 3 parts of polyoxyethylene decyl ether (ethylene oxide; 3 mol), 3 parts of polyoxyethylene decyl ether (ethylene oxide; 15 mol), 3 parts of lauryl alcohol, lauryl Add 3 parts of dimethylamine oxide and 12 parts of water, mix uniformly, and then emulsify using a colloid mill type emulsifier. Add 6 parts of sodium lauryl ether sulfate (ethylene oxide; 2 mol) and 70 parts of water to homogenize. To obtain an emulsion.
[0023]
The emulsion was evaluated for storage stability. Further, this emulsion was diluted with water so as to have a solid content of 10% to obtain a coating agent composition of the present invention, 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 so as to be 10% as a solid content, it is applied to a bucket containing 10 NBR rubber O-rings (25 mmφ) by using the dipping method. The presence or absence after the flow was examined. Thereafter, the liquid was removed by centrifugation, followed by hot-air drying at 90 ° C., and the appearance after drying (existence of spots, oil spots, overlapping marks) was examined.
Examples 2-4
An emulsion was obtained in the same manner as in Example 1 except that the constituent materials were changed to those shown in Table 1, and evaluated in the same manner.
Comparative Examples 1-4
An emulsion was obtained in the same manner as in Example 1 except that the constituent materials were changed to those shown in Table 1, and evaluated in the same manner.
[0024]
[Table 1]

Claims (2)

(A) Polydiorganosiloxane having a viscosity at 25 ° C. of 50 to 100,000 mPa · s; 100 parts by weight
(B) Monovalent alcohol having 8 to 12 carbon atoms; 0.1 to 10 parts by weight
(C) Polyoxyethylene alkyl ether; 1 to 50 parts by weight
(D) Alkylamine oxide compound; 0.1 to 10 parts by weight
(E) Polyoxyethylene alkyl etherate salt: 0.01 to 10 parts by weight
(F) Water; A coating agent composition comprising a silicone emulsion comprising an amount of 0.5 to 60% by weight of the silicone content as component (A) in the composition. (C) The coating agent composition according to claim 1, wherein the alkyl chain of the polyoxyethylene alkyl ether is C8 to C10.