JPH0628857B2 - Mold cleaning composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mold cleaning composition for cleaning a mold such as a mold for a thermosetting resin which is contaminated by repeated molding operations. Is.

[Conventional technology]

At the time of molding the thermosetting resin molding material, the release agent contained in the thermosetting resin molding material exudes to the surface of the mold to exert a releasing effect. When such molding is repeated, the releasability of the molded product becomes remarkably poor, and the surface of the oxidative deterioration layer of the release agent (the surface is not smooth like a mold) is transferred to the surface of the molded product, resulting in rough skin. Such a phenomenon occurs, which causes a problem that the surface of the molded product is not glossy. It is considered that this is because the release agent is sequentially laminated on the surface of the mold by repeated molding, and gradually deteriorates due to oxidation to form a hard release agent oxidative deterioration layer. Once such an oxidation-deteriorated layer of the mold release agent is formed on the mold surface, the mold release agent that oozes out from the mold material when molding the thermosetting resin molding material thereafter is the mold surface. Instead, it acts on the oxidation-deteriorated layer of the above-mentioned release agent, and it becomes impossible to exert a sufficient release effect. In order to solve such a problem, conventionally, a thermosetting melamine resin molding material was put in the mold and molded and cured, and the mold release agent oxidation deterioration layer on the mold surface was integrated with the molded product. The mold surface is cleaned by taking out a molded product in which the oxidation-deteriorated layer is integrated from the mold. In this case, formalin is produced as a by-product as a condensate of the thermosetting melamine resin molding material to generate an odor or the like, which deteriorates the working environment and causes a decrease in the cleaning work life.

[Problems to be solved by the invention]

As described above, when the mold surface is cleaned using the thermosetting melamine resin molding material, the working environment is deteriorated due to odor and the like, so that the unvulcanized rubber compound is used as the thermosetting melamine resin. It is used in place of the molding material and is vulcanized into a vulcanized rubber in the mold, and when the vulcanized rubber is formed, the mold release agent oxidation deterioration layer on the surface of the mold is integrated with the vulcanized rubber. A method of cleaning the surface of the mold by removing the vulcanized rubber from the mold has been proposed and partially implemented. In this case, the general formula The amino alcohol represented by is added. However, this amino alcohol evaporates during the vulcanization of the above-mentioned unvulcanized rubber-based compound and causes an odor. Therefore, this method also deteriorates the working environment and causes the cleaning workability to deteriorate.

The present invention has been made in view of such circumstances, and an object thereof is to provide a mold cleaning composition which has good mold cleaning properties and does not generate odor.

[Means for solving problems]

In order to achieve the above-mentioned object, the mold cleaning composition of the present invention is composed of a mixture of glycol ethers represented by the following general formula (1) and unvulcanized rubber.

That is, the present inventors, as a result of a series of studies on the cleaning effect on the mold such as the mold for thermosetting resin, the glycol ethers represented by the general formula (1) of the unvulcanized rubber Not only is it excellent in compatibility, but it is mixed in the above rubber and vulcanized in a mold that is contaminated by the oxidative deterioration layer of the release agent. The inventors have found that the surface of the mold can be easily cleaned by removing the vulcanized rubber from the mold in order to transfer it into the vulcanized rubber, and have reached the present invention. In this case, when the unvulcanized rubber is vulcanized in the mold, there is no odor such as formalin odor or amine odor, and there is no problem of deterioration of working environment.

The mold detergent composition of the present invention is obtained by using the glycol ethers represented by the general formula (1) and unvulcanized rubber, and is usually used in the form of a sheet.

The glycol ethers represented by the above general formula (1) include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether,
Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol diethyl ether,
Examples thereof include diethylene glycol buripyl ether, diethylene glycol dibutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and the like.

Among the glycol ethers represented by the above general formula (1), when n = 1 to ₂ and either R ₁ or R ₂ is hydrogen, the other is an alkyl group having 1 to 4 carbon atoms, and , R ₁ and R ₂ are both alkyl groups, it is preferably an alkyl group having 1 to 4 carbon atoms. When n has a value of 3 or more, the compatibility with rubber is lowered, and when the number of carbon atoms of the alkyl group is 5 or more, the permeability of the release agent to the oxidative deterioration layer is increased. The tendency is to become worse.

The glycol ethers may be used as they are, or may be mixed with water or an alcohol such as methanol, ethanol or n-propanol, or an organic solvent such as toluene or xylene. When mixed with an organic solvent, the amount of the organic solvent is usually 1
The amount is 50 parts by weight or less with respect to 00 parts by weight (hereinafter abbreviated as “part”), and most commonly 20 parts by weight or less. Further, a conventionally used release agent may be used in an appropriate amount, if necessary. When a release agent is used in combination, the amount of the release agent used is 10 parts or less per 100 parts of the total amount of unvulcanized rubber and glycol ethers, and most commonly 2 to 5 parts. Is done.

The unvulcanized rubber includes natural rubber (NR), chloroprene rubber (CR), butadiene rubber (BR), nitrile rubber (NBR), ethylene propylene terpolymer rubber (E
PT), ethylene propylene rubber (EPM), styrene butadiene rubber (SBR), polyisoprene rubber (I
R), butyl rubber (IIR), silicone rubber (Q),
It is possible to use, for example, one containing fluorine rubber (FKM) alone or a mixture as a main component, further containing a vulcanizing agent, and optionally a vulcanization accelerator and a reinforcing agent. This unvulcanized rubber is vulcanized into a vulcanized rubber in the mold. The above-mentioned unvulcanized rubber is preferably EPT, SB
R, NBR or a mixture thereof. Above EPT
Is a cyclic or acyclic copolymer having ethylene, α-olefin and a non-conjugated double bond. More specifically, EPT is a terpolymer composed of ethylene, α-olefin (particularly propylene) and the polyene monomers listed below, and the polyene monomers include dicyclopentadiene, 1,5-cyclooctadiene, and 1-cyclooctadiene. , 1-Cyclooctadiene, 1,6-
Cyclododecadien, 1,7-cyclododecadien,
1,5,9-cyclododecatriene, 1,4-cycloheptadiene, 1,4-cyclohexadiene, norbornadiene, methylenenorbornene, 2-methylpentadiene-1,4,1,5-hexadiene, 1,6-heptadiene , Methyl-tetrahydroindene, 1,4-hexadiene and the like. The copolymerization ratio of each monomer is preferably 30 to 80 mol% of ethylene and 0.1 to 20 of polyene.
It is a terpolymer such that the remainder is α-olefin in mol%. More preferably, ethylene is 30 to 60 mol%. And Mooney viscosity ML _{1 + 4} (10
It is preferably 0 to 20 ° C. Specific examples of the EPT include Mitsui EPT402 manufactured by Mitsui Petrochemical Industry Co., Ltd.
1, 4045 and 4070 can be listed. In addition, SBR has a styrene content of 15 to 30 mol%.
The Mooney viscosity ML _{1 + 4} (100 ° C.) of 20 to 80, preferably 35 to 60 is suitable. As a specific example, JSR-1502, 1507, and 1 manufactured by Japan Synthetic Rubber Co., Ltd.
You can raise 778. The NBR has an acrylonitrile content of 20 to 60 mol%, preferably 25 to
Mooney viscosity ML _{1 + 4} (100 ° C) of 20 to 45 mol%
It is suitable to use 85, preferably 30-70. As a specific example, N-234 manufactured by Japan Synthetic Rubber Co., Ltd.
L, the same 230S, and the same 230SH can be mentioned.

The glycol ethers are mixed with the unvulcanized rubber to form a mold detergent composition. In this case, glycol ethers are added to 100 parts of unvulcanized rubber,
Usually 10 to 60 parts are blended. 15 to 25 is preferable
It is about a part. The boiling point of the glycol ethers is preferably about 130 to 250 ° C. That is, the mold molding is usually performed at 150 to 185 ° C., and when the boiling point of the glycol ether is less than 130 ° C., the evaporation during cleaning is remarkable, and therefore the deterioration of the cleaning work environment occurs. On the contrary, if the temperature exceeds 250 ° C, it becomes difficult to evaporate and remains in the vulcanized rubber, and the strength of the vulcanized rubber when it is taken out from the mold is weak and the shape is deformed. The reason is that it becomes difficult to sufficiently remove the oxidation-deteriorated layer of the release agent from the mold surface, and the cleaning workability tends to be deteriorated.

In addition, it is also possible to mix an inorganic reinforcing agent (filler) such as silica, alumina, calcium carbonate, aluminum hydroxide and titanium oxide as a reinforcing agent in the mold cleaning composition of the present invention. In this case, the amount of the reinforcing agent used is preferably set to 10 to 50 parts per 100 parts of unvulcanized rubber. Further, as described above, it is possible to add a release agent. Examples of the releasing agent include stearic acid, zinc stearate, carnauba wax, montan wax, stearyl ethylenediamide and the like.
It is possible to add 1 to 10 parts of these to 100 parts of unvulcanized rubber.

〔The invention's effect〕

Since the mold cleaning composition of the present invention is configured as described above, it is possible to extremely easily remove the oxidation-deteriorated layer of the release agent formed on the mold surface to clean the mold surface. ,
At that time, no odor or the like is generated, and therefore the working environment is not deteriorated.

Next, examples will be described in detail.

[Example 1] 100 parts of ethylene propylene terpolymer rubber (EPT, manufactured by Mitsui Petrochemical Industry, Mitsui EPT4045), 20 parts of silica powder, 5 parts of titanium oxide, and induced peroxide 4
Parts, 1 part of stearic acid, and 20 parts of diethylene glycol dibutyl ether were kneaded by a kneading roll, and then formed into a sheet having a thickness of 7 mm by using a rolling roll to obtain a target mold cleaning composition.

[Example 2] Instead of diethylene glycol dibutyl ether, ethylene glycol monoethyl ether was used. A sheet-like mold cleaning composition was obtained in the same manner as in Example 1 except for the above.

Example 3 Styrene butadiene rubber (SBR, manufactured by Japan Synthetic Rubber Co., Ltd.,
JSR-1502) 100 parts, silica powder 20 parts,
Using 15 parts of aluminum hydroxide, 4 parts of organic peroxide, 1 part of zinc stearate, and 15 parts of diethylene glycol monomethyl ether, a sheet-like mold cleaning composition was obtained in the same manner as in Example 1.

[Example 4] Nitrile rubber (NBR, N-230 manufactured by Japan Synthetic Rubber Co., Ltd.)
SH) 100 parts, silica powder 20 parts, titanium oxide 5
Parts, organic peroxide 4 parts, stearic acid 1 part, and ethylene glycol monoethyl ether 15 parts to obtain a sheet-shaped mold cleaning composition in the same manner as in Example 1.

[Example 5] Use ratio of ethylene glycol monoethyl ether was 1
Reduced to 2 copies. Otherwise in the same manner as in Example 4, a sheet-like mold cleaning composition was obtained.

[Example 6] The amount of ethylene glycol monoethyl ether used was 55
Increased to the division. Otherwise in the same manner as in Example 4, a sheet-like mold cleaning composition was obtained.

Example 7 The SPT used in Example 3 was used instead of using EPT alone.
Used in combination with BR (50:50). A sheet-like mold cleaning composition was obtained in the same manner as in Example 1 except for the above.

Comparative Example 1 Instead of diethylene glycol dibutyl ether, 2-
Amino-2-methyl-1-propanol was used. A sheet-like mold cleaning composition was obtained in the same manner as in Example 1 except for the above.

Comparative Example 2 Toluene was used instead of ethylene glycol monoethyl ether. A sheet-like mold cleaning composition was obtained in the same manner as in Example 2 except for the above.

[Comparative Example 3] Diisopropyl ketone was used instead of diethylene glycol monomethyl ether. Otherwise in the same manner as in Example 3, a sheet-shaped mold cleaning composition was obtained.

Comparative Example 4 Ethanol was used in place of ethylene glycol monoethyl ether. Otherwise in the same manner as in Example 4, a sheet-like mold cleaning composition was obtained.

The mold cleaning composition obtained in the above Examples and Comparative Examples is sandwiched between thermosetting resin molding molds in which an oxidation-deteriorated layer of the release agent is formed, and vulcanized at 175 ° C. for 4 minutes, Immediately after vulcanization, the mold was opened and the molded vulcanized rubber was taken out. In this case, the detergency of the mold surface and the deterioration of the work environment due to the odor were investigated and summarized in the table below.

As is clear from the above table, according to the examples, the surface of the vulcanized rubber taken out from the thermosetting resin molding die, the release agent oxidation deterioration layer of the mold surface is transferred and adhered. As a result, the cavity surface of the mold was thoroughly cleaned. In addition, no odor was generated during this cleaning work, and therefore there was no problem in cleaning workability. On the other hand, in the comparative example, there were problems in mold cleaning property or odor, and good results could not be obtained.

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Claims (1)

[Claims] 1. A mold detergent composition comprising a mixture of glycol ethers represented by the following general formula (1) and unvulcanized rubber.