JP2001232647A - Cleaning composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning composition which can solve various problems in conventional mold cleaning, remove fouling efficiently without damaging a mold, and be handled safely. SOLUTION: At least one aminoalcohol selected from the group consisting of 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol, and aminoethyl ethanolamine is incorporated into the cleaning composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning composition used for cleaning a metal mold used for molding plastics. The cleaning composition of the present invention is particularly preferably used as a cleaning composition for a mold whose surface is contaminated by repeated use.

[0002]

2. Description of the Related Art Molds used for molding plastics are made of resin scum as a raw material of a molded product or a compounding agent as an auxiliary material leached on the surface of the mold. Release agent accumulates on the mold surface. Such dirt accumulates on the surface of the mold as the mold is used, and significantly affects the releasability, appearance, dimensional accuracy, and the like of the molded product. Therefore, it is necessary to clean the mold at a certain frequency. Conventionally, for example, the following method is known as a method for cleaning the mold.

[0003] A method for removing contaminants by wiping with an organic solvent such as a chlorine-based solvent, an aromatic-based solvent, or acetone. A method for physically removing dirt with an abrasive. A cleaning method using an alkaline solution. On the other hand, they are used in combination as needed.

[0004]

However, the conventional cleaning method using an organic solvent has the following problems. That is, chlorinated solvents have serious problems in terms of toxicity, environmental pollution, etc. Solvents such as aromatic solvents, acetone, etc. are not only safe and toxic, but also remove resin residue that adheres strongly. To remove, it is necessary to immerse in a solvent for a long time, and it cannot be removed efficiently. Also, in the method of physically removing dirt with an abrasive, an operator needs to be careful to prevent damage to the mold, and the working efficiency is poor. further,
In the cleaning method using an alkaline solution, a caustic soda solution having a high concentration is usually used, so that special attention must be paid to the safety of workers.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to solve various problems in conventional mold cleaning and to efficiently remove dirt without causing scratches or the like on the mold. It is an object of the present invention to provide a cleaning composition capable of safer handling.

[0006]

The inventors of the present invention have conducted various studies to solve the above problems, and as a result, have found that a specific amino alcohol has an effect of removing resin residue adhering to a plastic molding die. High and found to be particularly useful as a mold cleaning composition. In addition, by mixing and using an organic solvent having solubility in the resin compounding agent and the like, the composite contaminants of the mold can be more efficiently removed, and further, water or polyhydric alcohol is mixed as a poor solvent. It was found that the cleaning effect was further improved by using
The present invention has been completed.

That is, the present invention comprises at least one amino alcohol selected from the group consisting of 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol and aminoethylethanolamine. It is a cleaning composition characterized by the following.

Hereinafter, the present invention will be described in more detail.

The present inventors have conducted various searches for substances that peel off and remove resin residue attached to a plastic mold. As a result, 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol, It has been found that aminoethylethanolamine has a particularly high peeling effect on a resin and is useful for a cleaning composition. These amino alcohols can be used alone or
More than one species may be used in combination.

When the organic solvent such as acetone or aromatic solvent used in the past is washed only with a solvent which is soluble in resin residue, the resin residue is dissolved due to its large molecular weight. The speed is too slow to remove efficiently. In addition, when only a solvent having low solubility for the resin residue is used for washing, the resin residue does not dissolve or peel off and cannot be removed.

In the present invention, by mixing the amino alcohol with an organic solvent having solubility in a resin compounding agent and the like, a resin residue adhering to a mold and a resin such as a compounding agent accumulated therein are removed. Of contaminants can be removed at the same time. In the compounding agent of the resin, for example, various kinds of substances such as an antioxidant, a metal deactivator, a resin modifier, and a flame retardant are used, and the solubility is high depending on the compounding agent used in the resin. Solvents can be used. As such an organic solvent, amino alcohols are dissolved,
There is no particular limitation as long as it is a uniform solution as the cleaning composition, but in consideration of the influence on the mold and the effect on the operator, a substance having a high flash point and a metal having low corrosiveness and low toxicity is preferable. Can be used. Specifically, 1,
Ethers such as 4-dioxane, tetrahydrofuran and tetrahydropyran; alcohols such as furfuryl alcohol and tetrahydrofurfuryl alcohol; ketones such as methyl ethyl ketone; esters such as methyl formate, ethyl formate and methyl acetate; N, N-dimethyl Acid amides such as formamide, N-methyl-2-pyrrolidone, N-
Examples include pyrrolidones such as ethyl-2-pyrrolidone, and glycol ethers such as ethylene glycol methyl ether, diethylene glycol methyl ether, and dipropylene glycol methyl ether. Of these,
Tetrahydrofurfuryl alcohol, N-methyl-2-
Pyrrolidone, dimethylimidazolidinone, dipropylene glycol methyl ether, etc. are highly flammable and toxic,
It has characteristics such as low odor, and is particularly preferably used from the viewpoint of worker safety. Two or more of these organic solvents may be used in combination.

The composition of the amino alcohol and the organic solvent is preferably in the range of 1 to 80% by weight and 20 to 99% by weight, respectively. When the compounding amount of the organic solvent is less than 20% by weight, the solubility of the mold contaminants due to the resin compounding agent or the like does not improve, and the effect of simultaneously removing the complex contaminants of the mold does not improve. If the amount of the organic solvent exceeds 99% by weight, that is, if the amount of the amino alcohol is less than 1% by weight, the effect of peeling off the resin adhered to the mold may not be exhibited.

[0013] In addition to the organic solvent, a solvent having low solubility (hereinafter, referred to as a poor solvent) with respect to the resin residue attached to the mold is mixed and used to remove the amino alcohol resin residue. The effect can be further enhanced.

In this case, the composition of the amino alcohol, the organic solvent and the poor solvent is 1 to 75% by weight,
The ranges of 0 to 94% by weight and 5 to 79% by weight are preferred.
When the compounding amount of the poor solvent is less than 5% by weight, the effect of peeling off resin residue of amino alcohols is not improved. On the other hand, if the compounding amount of the poor solvent exceeds 79% by weight, the compounding amount of the amino alcohols and / or the organic solvent decreases, so that the effect of removing the resin residue and the resin compounding agent is not promoted.

As such a poor solvent, water and polyhydric alcohol, which are poor solvents for many resins, are preferably used. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, glycerin and the like.

As described above, the cleaning composition of the present invention is characterized by containing amino alcohols. However, the cleaning composition has a surface active property for the purpose of improving rinsing properties and preventing re-adhesion of mold contaminants. An agent or an antifoaming agent thereof can be added, a metal chelating agent can be added for the purpose of removing slight rust, dissolving a metal salt, or the like, or a rust inhibitor can be added for rust prevention after washing the mold. The compounding amount is preferably in the range of 0 to 20% by weight based on the weight of the cleaning composition. If the amount exceeds 20% by weight,
The amounts of the amino alcohols and the organic solvent that are the cleaning components are reduced, and the cleaning effect may be reduced.

Although the cleaning composition of the present invention is particularly effective for cleaning molds, it is also applicable to other uses, such as cleaning waxes, oily and aqueous machine oils, greases and the like. Needless to say,

[0018]

The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples.

Examples 1 to 29 and Comparative Examples 1 to 43 Various cleaning compositions shown in Tables 1 and 2 were prepared, and a mold cleaning test was conducted.

First, using a mold for casting a test piece of a polycarbonate resin, a mold release agent is applied each time, and a molding temperature of 300 μm is applied.
The molding of the polycarbonate resin was repeated 50 times at a mold temperature of 80 ° C. and a mold temperature of 80 ° C. The resin mold, the altered release agent and the like were firmly adhered to the mold after molding. This mold was put into a cleaning composition whose temperature had been adjusted to 50 ° C. in a cleaning tank of an ultrasonic cleaning machine (39 kHz, 200 W) in advance, and was washed for 60 minutes. Detergency was evaluated by observing the mold surface and determining the time during which contaminants were almost completely removed. The criteria are as follows.

Removal time of contaminants 未 満: less than 10 minutes ：: 10 minutes or more and less than 30 minutes Δ: 30 minutes or more and less than 60 minutes X: 60 minutes or more The results are summarized in Tables 1 and 2.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

The cleaning composition of the present invention is capable of simultaneously removing, in a short time, a resin residue and a release agent, which are contaminants peculiar to a mold, so that the mold can be efficiently cleaned. Since it can be performed, it is extremely useful industrially.

Claims (6)

[Claims] 1. It comprises at least one amino alcohol selected from the group consisting of 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol and aminoethylethanolamine. Cleaning composition. 2. An organic solvent containing at least one amino alcohol selected from the group consisting of 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol and aminoethylethanolamine. A cleaning composition comprising: 3. The cleaning composition according to claim 2, wherein the compositions of the amino alcohol and the organic solvent are 1 to 80% by weight and 20 to 99% by weight, respectively. 4. at least one amino alcohol selected from the group consisting of 2-aminoethanol, 3-aminopropanol, 2-aminopropanol, N-methylaminoethanol and aminoethylethanolamine;
A cleaning composition comprising a solution containing an organic solvent and at least one poor solvent selected from the group consisting of water and polyhydric alcohols. 5. The composition of an amino alcohol, an organic solvent and a poor solvent, wherein the composition is 1 to 75% by weight, 20 to 94% by weight and 5 to 79% by weight, respectively.
3. The cleaning composition according to item 1. 6. The method according to claim 1, wherein the organic solvent is at least one selected from the group consisting of tetrahydrofurfuryl alcohol, N-methyl-2-pyrrolidone, dimethylimidazolidinone, and dipropylene glycol methyl ether. The cleaning composition according to any one of claims 2 to 5.