JPH1121482A - Coating release agent composition - Google Patents

Abstract

[57] [Problem] To provide a coating film peeling agent suitable for a coated product made of aluminum, which has an excellent coating film peeling force, has high safety, and has a bad influence on a working environment. Provided is a novel coating film release agent composition which has a small amount and a stable release performance for a long period of time. SOLUTION: It contains (A) two or more kinds of compounds belonging to different classes selected from the group consisting of organic acids, aromatic alcohols, glycol ethers, and glycols, and (B) inorganic acids. A coating film stripping composition comprising an aqueous solution, and a coating film stripping method, which comprises contacting the coating stripping composition with a coating film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a coating film release agent composition.

[0002]

2. Description of the Related Art A large amount of paint adheres to various tools for painting, for example, jigs, hangers, nets, snowboards, masking jigs, etc. at the time of painting. Need to be removed. In addition, it is necessary to remove an unnecessary portion of the coating film and a coating film of a defective coating product on the object to be coated.

[0003] For products made of aluminum or an aluminum-based alloy, a stripping agent containing methylene chloride as a main component has been widely used as a coating stripper capable of stripping a coating without corroding the material. . For example, a release agent obtained by adding nitric acid and a surfactant to methylene chloride, about 10 to 20 parts by weight of formic acid to 89 to 75 parts by weight of methylene chloride, and a solid carboxylic acid such as lauric acid; Solid alcohols, strippers containing about 1 to 5 parts by weight of esters thereof (Japanese Patent Publication No. 62-59749), about 70 to 95 parts by weight of methylene chloride, about 1 to 15 parts by weight of aprotic polar solvent, saturated Alternatively, a release agent to which about 1 to 15 parts by weight of an unsaturated monohydric alcohol and about 1 to 15 parts by weight of an alcoholate are added (JP-A-5-171076) is known.

However, these strippers have a large evaporation loss due to the low boiling point of methylene chloride, which is the main component, at 40 ° C., and the evaporation loss is suppressed by a method such as dissolving solid paraffin. There is a problem that even if left for about a day, a large amount of evaporates. In addition, since methylene chloride is a substance that violates the Occupational Safety and Health Law, various facilities are required to maintain the working environment.
The concentration of methylene chloride in wastewater is strictly regulated to 0.2 mg / liter or less, and in order to satisfy this requirement, it is necessary to perform treatment with distillation equipment and explosive treatment, etc. Equipment is required. In addition, there is a great economic problem, such as the necessity of a facility for recovering methylene chloride diverging into the atmosphere.

[0005] Therefore, in order to solve the above-mentioned problems caused by using methylene chloride, development of a new release agent which does not use methylene chloride has been desired.

[0006]

SUMMARY OF THE INVENTION The main object of the present invention is to:
A coating film stripping agent that hardly corrodes the material even when used on painted products made of aluminum-based materials. It has excellent coating film peeling power, high safety, and work environment. It is an object of the present invention to provide a novel coating film release agent composition which has a small adverse effect on coating and has stable release performance for a long period of time.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the problems of the prior art as described above, and as a result, have been classified into organic acids, aromatic alcohols, glycol ethers, and glycols. A composition comprising an aqueous solution containing two or more compounds belonging to different classes selected from the compounds belonging thereto and an inorganic acid as an essential component has excellent coating film peeling performance, and furthermore, the component used is low. Because it is volatile, it is highly safe, can exhibit good release performance with little variation in composition for a long period of time, and even when used as a coating release agent for painted products made of aluminum-based materials. It has been found that the corrosion is small, and particularly when nitric acid is used as the inorganic acid, the surface of the aluminum-based material is passivated to hardly cause corrosion of the material. And
It has been found that when peeling is performed while keeping the water content in the release agent within a certain range, particularly excellent peeling performance can be exhibited, and the present invention has been completed.

That is, the present invention provides the following coating film remover composition and coating film removing method.

1. It comprises (A) two or more compounds belonging to different classes selected from the group consisting of organic acids, aromatic alcohols, glycol ethers, and glycols, and (B) an aqueous solution containing inorganic acids. Coating release agent composition.

[0010] 2. (A) 10 to 96% by weight of component, (B)
2. The coating film remover composition according to the above item 1, comprising 1 to 50% by weight of a component and 3 to 70% by weight of water.

3. 3. The coating film stripping composition according to the above item 1 or 2, wherein the inorganic acid is nitric acid.

4. The organic acid is formic acid, the aromatic alcohol is benzyl alcohol, the glycol ether is at least one of ethylene glycol monobutyl ether and diethylene glycol monobutyl ether, and the glycol is propylene glycol. Coating release agent composition.

5. A method for removing a coating film, comprising bringing the coating film removing agent composition according to any one of the above items 1 to 4 into contact with a coating film.

6. The water content in the coating film remover composition is 3 to 7
6. The method for peeling a coating film according to the above item 5, wherein the coating film is peeled while keeping the weight at 0 wt%.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The release agent composition of the present invention comprises two or more compounds belonging to different classes selected from the group consisting of organic acids, aromatic alcohols, glycol ethers, and glycols. (Hereinafter sometimes referred to as component (A)), and an aqueous solution containing inorganic acids. Here, as the component (A), at least two types of compounds belonging to different classes from among the compounds belonging to the respective classes of organic acids, aromatic alcohols, glycol ethers, and glycols may be used. is necessary. At this time, the compounds belonging to the same class can be used alone or in combination of two or more.

In the component (A), specific examples of the organic acids include formic acid, acetic acid, oxalic acid, maleic acid, lactic acid and the like. These may be used alone or in combination of two or more. be able to. Of these, formic acid is preferred because it is strongly acidic and inexpensive.

Specific examples of aromatic alcohols include benzyl alcohol, 4-methylbenzyl alcohol,
-Ethylbenzyl alcohol, phenethyl alcohol, etc., and these can be used alone or in combination of two or more. Of these, benzyl alcohol is preferred because it is inexpensive.

Specific examples of glycol ethers include:
Ethylene glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, 2- (methoxymethoxy) ethanol, 2- (hexyloxy) ethanol, and 2-phenoxyethanol Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monophenyl ether, etc .; diethylene glycol ethers; triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopropyl ether Ethylene glycol Mono butyl ether, triethylene glycol ethers such as triethylene glycol monomethyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether,
Propylene glycol ethers such as propylene glycol monopropyl ether, propylene glycol monobutyl ether and propylene glycol monophenyl ether; dipropylene glycol monomethyl ether;
Dipropylene glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol monophenyl ether; butylene glycol monomethyl ether, butylene glycol monoethyl ether, butylene glycol monopropyl ether Butylene glycol ethers such as butylene glycol monobutyl ether and butylene glycol monophenyl ether can be used, and these can be used alone or in combination of two or more. Among them, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and the like are preferable because they have high peeling performance and stability and are inexpensive.

Specific examples of glycols include ethylene glycol, propylene glycol, butylene glycols, diethylene glycol, dipropylene glycol, triethylene glycol, glycerin and the like. These may be used alone or in combination of two or more. Can be blended. Of these, propylene glycol is preferred from the viewpoint of environmental health.

[0020] In the coating film release agent composition of the present invention,
Specific examples of the inorganic acids used in combination with the component (A) include nitric acid, hydrochloric acid, phosphoric acid, and sulfuric acid. These can be used alone or in combination of two or more. Among them, nitric acid is particularly preferable when used for a painted product made of an aluminum-based material because it can stabilize the surface of the aluminum-based material.

Among the above-mentioned components, the aromatic alcohols, glycol ethers and glycols of the component (A) are partially esterified with organic acids, inorganic acids and the like in an aqueous solution when each component is blended. It may be formed. or,
These components may be blended in a state where an ester is formed in advance with an organic acid, an inorganic acid, or the like.

The composition of the present invention comprises an aqueous solution containing two or more compounds of different classes selected from the group consisting of organic acids, aromatic alcohols, glycol ethers and glycols, which are components (A), and inorganic acids. The proportion of each component is about 10 to 96% by weight (hereinafter simply referred to as%) of the component (A), preferably 40 to 9 based on the whole composition.
About 3%, about 1 to 50% of inorganic acids, preferably about 2 to 2
The concentration may be about 0%, about 3 to 70%, preferably about 5 to 40%.

As for the component (A), the total amount may be within the above-mentioned range, but the preferable compounding amount of the compound belonging to each category is 1 to 50%, more preferably 2 to 30%, of organic acids. About 2 to 80% of aromatic alcohols,
More preferably about 5-60%, glycol ethers about 1-90%, more preferably about 2-70%, and glycols about 0.1-80%, more preferably about 1-80%
It is about 70%.

The composition of the present invention can control the flash point to some extent by adjusting the amount of each component within the range of the mixing ratio described above, and is a non-dangerous substance which is industrially easy to handle. You can also.

[0025] The coating release agent composition of the present invention may further contain, if necessary, various chelating agents, surfactants, anticorrosives, viscosity modifiers, which are blended in the conventional coating release agent composition. A coloring agent or the like can be appropriately added. Also, during the stripping operation, the surface of the stripping composition may be sealed with paraffin or the like to minimize the composition change of the stripping composition due to evaporation or oxidation reaction with oxygen in the air. it can.

The composition of the present invention is an aqueous solution containing the above components. In the composition, the order of mixing the components is arbitrary.For example, in addition to mixing the components except the inorganic acids in advance to form an aqueous solution, and adding and using the inorganic acids,
By mixing water and components other than the inorganic acids in advance, and mixing the diluted inorganic acids with water and using the resulting mixture as an aqueous solution, heat generation during mixing can also be suppressed. Also,
In addition to using each component in advance as an aqueous solution, the components may be mixed and used as an aqueous solution by the above-described method immediately before use. These aqueous solutions are generally used as a homogeneous solution, but they can be used in a thickened state, in an emulsion or in a non-uniform state.

In the composition of the present invention, since the components used have a relatively high boiling point and low volatility, the composition does not fluctuate and a good peeling amount can be exhibited for a long period of time. In addition, since the evaporation loss is small, it is economically advantageous, the safety is high, and the working environment is hardly deteriorated.

In order to peel the coating film using the composition of the present invention, the coating film of the present invention is brought into contact with the coating film to be peeled, and then the coating film is naturally peeled off, or is brushed or the like. It may be left until it can be easily peeled off. The method of bringing the composition of the present invention into contact with the coating film is not particularly limited, and the composition of the present invention may be brought into contact with the coating film to be peeled by a method such as dipping, coating, spraying, or showering. As a treatment condition, the contact may be performed in the atmosphere at room temperature or under heating, and the heating can promote peeling. The heating temperature is
The temperature may be lower than the boiling point of the composition of the present invention.
The temperature may be set to about 60 ° C. or less. The contact time is not uniform depending on the concentration of each component, the processing temperature, the thickness of the coating film, the type, the history, the coating method, and the like, but may be usually about 5 minutes to 2 hours. In order to further shorten the stripping time, the composition of the present invention may be physically moved by a method such as stirring or the object to be stripped may be rocked in the composition.

In the present invention, in particular, the release agent composition is brought into contact with the coating film while keeping the water content of the release agent composition at about 3 to 70%, preferably about 5 to 40%. Preferably, this makes it possible to exhibit particularly excellent peeling performance. This is because, when the release agent composition contains water in the above range, a moderate amount of hydrogen ions are dissociated from inorganic acids, organic acids, and the like contained in the composition, and good release performance is exhibited. It seems to have been done. If water evaporates from the release agent composition during the stripping operation and the water content falls below the above range, water may be supplied continuously or intermittently so that the water content falls within the above range.

By leaving the composition of the present invention in contact with the coating film and leaving it to stand according to the various methods described above,
Phenomena such as dissolution, swelling, and deterioration occur, and the coating film comes off spontaneously, or becomes in a state where it can be easily removed by brushing or the like.

Next, if necessary, the coating film may be removed by brushing or the like, and then washed with water or the like.

The type of the coating film to be peeled off by the composition of the present invention is not particularly limited.
Epoxy paints, polyester paints, melamine paints, urethane paints, alkyd paints, urea paints, silicon resin paints, lacquer paints, etc. Can be processed. Further, a coating film treated with a primer or a plasma may be used, or a coating film obtained by stacking a plurality of coating films may be used. Further, the coating film may contain zinc, tin, titanium, other metals, and the like.

There is no particular limitation on the object to be stripped from which the stripping composition of the present invention can be used, as long as the material is not corroded by the composition of the present invention. In particular, the composition of the present invention hardly corrodes a coating film formed on an aluminum-based material made of aluminum or an aluminum-based alloy when the coating film is peeled off. It can be effectively used as a film release agent. Further, the composition of the present invention is not limited to an aluminum-based material, and is coated with a material that is not corroded by the composition of the present invention or that is allowed to corrode, such as various metal materials, plastics, ceramics, and wood. An article can be a processing object. Examples of coatings to be subjected to coating film peeling with the composition of the present invention include, for example, aluminum sash parts for houses and healthy living, precision parts such as electronics and watches, electric products, automobile parts, airplane parts, high-quality parts. Materials in various fields such as molecular parts can be targeted. Furthermore, coating tools such as jigs, hangers, nets, and snowboards used for coating can also be processed.

[0034]

Industrial Applicability The coating film remover composition of the present invention has a very excellent coating film removing effect, and in particular, hardly corrodes aluminum-based materials. It is very useful as a coating film remover. In addition, since the components used are low in volatility, safety is high and the working environment is hardly deteriorated. Further, since there is little change in composition, good release performance can be exhibited for a long period of time.

In particular, when peeling is performed while maintaining the water content in the composition of the present invention within a certain range, excellent peeling performance can be exhibited for a long period of time.

[0036]

The present invention will be described in more detail with reference to the following examples.

Example 1 Each release agent composition was prepared by dissolving each component in water according to each of the following formulations.

Invention product 1 Formic acid (88% aqueous solution) 11% Benzyl alcohol 10% Ethylene glycol monobutyl ether 51.5% Propylene glycol 1% Nonionic surfactant 0.5% Water 20% Nitric acid (67.5% Aqueous solution) 6% invention product 2 formic acid (88% aqueous solution) 11% benzyl alcohol 10% ethylene glycol monobutyl ether 16.5% diethylene glycol monobutyl ether 25% propylene glycol 1% nonionic surfactant 0.5% water 30% Nitric acid (67.5% aqueous solution) 6% Invention product 3 Formic acid (88% aqueous solution) 11% Ethylene glycol monobutyl ether 62.5% Nonionic surfactant 0.5% Water 20% Nitric acid (67.5% aqueous solution) 6% Invention product 4 Formic acid (88% aqueous solution) 11% Diethylene Glycol monobutyl ether 62.5% Nonionic surfactant 0.5% Water 20% Nitric acid (67.5% aqueous solution) 6% Inventive product 5 Formic acid (88% aqueous solution) 13.3% Benzyl alcohol 13.3% Propylene glycol 36.2% Nonionic surfactant 0.5% Water 30% Nitric acid (67.5% aqueous solution) 6.7% Present product 6 Benzyl alcohol 10% Ethylene glycol monobutyl ether 63.5% Nonionic Surfactant 0.5% Water 20% Nitric acid (67.5% aqueous solution) 6% Comparative product 1 Ethylene glycol monobutyl ether 73.5% Nonionic surfactant 0.5% Water 20% Nitric acid (67.5% Aqueous solution) 6% Comparative product 2 Propylene glycol 73.5% Nonionic surfactant 0.5% Water 20% Nitric acid (67.5% aqueous solution) 6% Comparative product 3 Formic acid 11% Nonionic surfactant 0.5% Water 82.5% Nitric acid (67.5% aqueous solution) 6% Comparative product 4 Benzyl alcohol 93.5% Nonionic surfactant 0.5% Nitric acid (67.5% aqueous solution) 6% Comparative product 5 Ethylene glycol monobutyl ether 93.5% Nonionic surfactant 0.5% Nitric acid (67.5% aqueous solution) 6% Comparative product 6 Propylene glycol 93.5% Nonionic surfactant 0.5% Nitric acid (67.5% aqueous solution) 6% As a test piece, a transparent acrylic resin electrodeposited on an aluminum plate to a thickness of 12 μm was used and kept at a liquid temperature of 40 ° C. The test piece was immersed in each of the release agent compositions described above, and the state of the coating film of the test piece was visually observed every minute. Each release agent composition was used 2-3 hours after preparation. Table 1 below shows the time until the coating film is peeled off.

Table 1 Release agent composition Time (min) until the coating film is peeled (minutes) Inventive product 17 Inventive product 27 Inventive product 3 18 Inventive product 4 19 Inventive product 5 11 Inventive product 6 18 Comparative product 1 40 or more Comparative product 2 140 or more Comparative product 3 140 or more Comparative product 4 40 or more Comparative product 5 140 or more Comparative product 6 140 or more As is clear from the above results, when using the composition of the present invention, (A)
When Comparative Products 1 to 6 each containing only one component were used, the coating film did not peel off even after 40 minutes.

Example 2 The composition of the product 1 of the present invention used in Example 1 was left in the air at 40 ° C. for 38 hours to reduce the water content to 2%, and the composition was used and the same as in Example 1 And a coating film peeling test was performed.

Further, with respect to a composition having the same composition,
After leaving at 40 ° C. in the air to reduce the water content, water was added to make each water content of 10%, 15%, 20% and 30%, and then each composition was used 2 hours later. A coating film peeling test was performed in the same manner as in Example 1. The results are shown in Table 2 below.

Table 2 Moisture (%) Time (min) until the coating film is peeled 260 or more 10 7 15 7 20 7 30 7 As is clear from the above results, the composition of the present invention has a water content of If the water content falls within a certain range, good peeling performance can be exhibited.

Claims (6)

[Claims] 1. A method comprising: (A) two or more compounds belonging to different classes selected from the group consisting of organic acids, aromatic alcohols, glycol ethers, and glycols; and (B) inorganic acids. A coating film stripping composition comprising an aqueous solution. 2. The coating stripping composition according to claim 1, comprising 10 to 96% by weight of component (A), 1 to 50% by weight of component (B), and 3 to 70% by weight of water. 3. The coating film remover composition according to claim 1, wherein the inorganic acid is nitric acid. 4. The method according to claim 1, wherein the organic acid is formic acid, the aromatic alcohol is benzyl alcohol, the glycol ether is at least one of ethylene glycol monobutyl ether and diethylene glycol monobutyl ether, and the glycol is propylene glycol. The coating film release agent composition according to any one of the above. 5. A method for removing a coating film, comprising bringing the coating composition according to any one of claims 1 to 4 into contact with a coating film. 6. The method for removing a coating film according to claim 5, wherein the coating film is removed while maintaining the water content in the coating film removing agent composition at 3 to 70% by weight.