JPH0238146B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Application of the Invention) The present invention relates to the peeling off of weather-resistant paint films (paint films) such as paint, acrylic baking paint, and melamine resin.
It relates to a paint film stripper used for removal. (Prior art) A variety of stripping agents have been proposed for use in stripping paint films (paint films), and among them, paint films using halogen hydrocarbons such as methylene chloride or trichloroethylene as the main solvent Stripping agents are widely used in practical use. However, the halogenated hydrocarbons that are the components of these strippers are volatile and toxic, so they must not be used during application to the paint film.
Even after the application is complete, toxic methylene chloride or trichlorethylene vapor is generated, damaging the health of workers and causing environmental pollution. In addition, the swollen paint film is removed using a scraper or wire brush, but this peeling process itself is not that easy, and if you make a mistake in determining the optimal time for the paint film to swell, the swollen paint film will re-adhere. There are many things. In addition, when the paint film is removed, solvents such as methylene chloride and other remover components (compositions) that remain in the paint film are removed.
These substances adhere to the skin of fingers, hands, face, etc., causing irritation (itching) and rough skin. OBJECTS OF THE INVENTION The primary object of the present invention is to provide a safe and effective paint stripper that solves the problems of known strippers, such as toxicity, environmental pollution, and difficulty in stripping operations. (Means for Solving the Problems) In order to solve the above problems, the paint film remover according to the present invention has (a) general formula:

【formula】

[Formula] or

[Formula] (In the formula, R ₁ , R ₂ and R ₃ represent an alkyl group having 1 to 4 carbon atoms)
20 to 70% (by weight, same below), (b) General formula

[Formula] (In the formula, R represents a C ₁ to C ₄ alkyl group or a benzyl group, and X is an atomic group -C ₂ H ₄ - or -C ₂ H ₄ -
5 to 30% of glycol ether acetate represented by O-C ₂ H ₄ ), and (c) ω-lower alkoxy-lower alkylamine 2
~40%. That is, the present invention has three essential components: (a) aromatic hydrocarbon represented by the above general formula (b) glycol ether acetate represented by the above general formula (c) ω-lower alkoxy-lower alkylamine, Furthermore, as explained below, if necessary, the following ingredients are added: (d) glycol ether (e) anionic surfactant (f) water (g) lower alkanolamine (h) evaporation inhibitor, and (i) thickener. It is a mixture of auxiliary ingredients in specific ratios, which makes the whole product uniform and safe in itself, as described below [Example]
As shown in Figure 2, it has excellent peeling ability and is characterized by the ability to effectively remove various water-insoluble coatings with simple operations. Of the three essential components above, component (a) is toluene,
xylene, ethylbenzene, propylbenzene,
Aromatic hydrocarbons such as butylbenzene or mixtures thereof are commercially available as raw materials for paints, so it is convenient to use such mixtures. The above-mentioned aromatic hydrocarbons have excellent solubility, permeability, and swelling properties for various paint films, and are therefore effective in removing paint films. In particular, hydrocarbons with high boiling points and high flash points When one of the above types is selected, the evaporation rate of the solvent is reduced, and as a result, the action of the stripping agent continues for a long time, and even stubborn coating films can be swollen and softened.
Moreover, these high boiling point and high flash point hydrocarbons are
In addition to reducing the risk of ignition, it is also possible to limit the amount of nucleic acid in the solvent to the atmosphere, which is beneficial for improving the working environment and preventing environmental pollution. In addition,
The blending amount of these aromatic hydrocarbons is 20% in the composition.
~40%. The film stripper of the present invention contains glycol acetate (b) as a co-solvent in an amount of 5 to 30% in the composition.
Examples of component (b) include glycol ether acetates such as methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, benzyl cellosolve acetate, carbitol acetate, and butyl carbitol acetate, but particularly preferred cosolvents include:
These are glycol ether acetates that are easily soluble in water, such as cellosolve acetates and carbitol acetates. The amount of this auxiliary solvent is within the range of 5 to 30% in the composition, and is 1/1% of component (a).
It is desirable that the amount is 2 or less. The ingredients (a) and (b) above are added to the composition as a release accelerator.
Lower alkanolamines such as monoethanolamine or monoisopropanolamine (g) within 40%
A mixture containing the above can be used as it is for removing paint films, but it tends to undergo phase separation, making it inconvenient to use and less effective. The present inventor conducted studies to solve this drawback, and found that when monohydric or dihydric alcohols such as methanol, ethanol, and ethylene glycol are used as phase separation inhibitors, the peeling force of the coating decreases. Aliphatic lower saturated or unsaturated amines such as ethylamine and monoarylamine are unsuitable for practical use due to their own unpleasant odor, and alicyclic amines such as benzylamine have poor stripping ability, and 2- It was recognized that intermediate to permanent aliphatic amines such as ethylhexylamine or monolaurylamine have a low ability to prevent phase separation. However, 3-methoxypropylamine or 3
It has become clear that ω-lower alkoxy-lower alkylamines (c) such as -ethoxypropylamine have favorable performance in terms of odor, peeling ability, and phase separation prevention ability. Therefore, ω
-Lower alkoxy-lower alkyl amines are necessary to constitute the compositions of the invention. The appropriate amount of component (c) is 2 to 40% of the total amount of the composition.
It is. By keeping the blending ratio within this range, it is possible to obtain an ideal coating stripping agent that is free from phase separation, has excellent stripping ability, and does not emit unpleasant odors. The paint film stripping agent according to the present invention can be further added with glycol ethers (d) such as ethyl cellosolve carbitol or butyl cellosolve and water (f) as necessary to further remove some paint films. Increase capacity. Suitable addition ratios of these auxiliary components (d) and (f) are 30% and 30%, respectively, based on the total amount of the composition.
Less than 20%. Addition of the anionic surfactant (e) does not affect the stripping effect itself, but facilitates washing of the solvent from the treated surface with water. A suitable addition ratio thereof is 0.1 to 5% based on the total amount of the composition. (i) Lipophilic thickeners such as methylcellulose are
It is useful for uniformly applying the release agent of the present invention onto a coating film to be removed using a brush or a roller. The suitable additive range is 1 to 5%, and the viscosity is 1000 to 1000.
It is in the range of 3000cps. Furthermore, (h) adding a wax such as paraffin wax as an evaporation inhibitor suppresses the evaporation of the solvent, improving the working environment and maintaining the effectiveness of this stripping agent, making it ideal for stubborn paint films. The peeling effect is increased. A suitable additive for waxes is 0.5
The range is from 2.0% to 2.0%. The constituent components of the paint film stripping agent according to the present invention and their appropriate blending ratios are as described above, but in actual products, it is preferable that each component is present in an appropriate balance. As a result of various tests, the present inventor found that (a) the amount of the aromatic hydrocarbon (a) as the main solvent is twice or more than that of the glycol ether acetate as the auxiliary solvent (i.e., a≧b); b) In addition to essential components (a), (b) and (c), component (d) glycol ether and lower alkanolamines (g)
It has been found that it is preferable that the blending ratio of the five-component system when blending approximately satisfies the relational expression (a+b+d)≦6(c+g) in order to harmonize the performance of the product. (How to use) The paint film remover according to the present invention can be applied to a film-like body formed from various paints and adhesives applied on wood, metal, mortar, and other various materials (therefore, “Coating film” mentioned repeatedly in this specification
The term is not limited to just a coating of paint;
It is a broad concept that also includes thin films formed with adhesives. ). There are two ways to use it: dipping and coating. In any case, the paint film to be peeled to which the paint film stripping agent of the present invention has been applied is in a state where it has floated up from the coated surface or has been partially dissolved due to the effects of penetration, swelling, dissolution, etc. of the paint film stripping agent of the present invention. Therefore, it can be easily removed by scraping it with a trowel or scraper. Under normal conditions, it is sufficient to perform the coating (or dipping) → peeling process only once, but it is possible to apply two or three coats on a deteriorated paint film that is extremely difficult to peel off. For this purpose, it is preferable that the present release agent be applied twice or three times (dipped). This multi-coating (or multi-dipping) method allows even stubborn coatings to be completely removed. Hereinafter, embodiments of the invention will be described with reference to examples, but the examples are, of course, for illustrative purposes and are not intended to limit the idea of the invention. Example 1 Aromatic mixed solvent 50% Cellosolve acetate 19.8〃 3-methoxypropylamine 30〃 Anionic surfactant 0.2〃 The above components are stirred and mixed until uniform. Example 2 Aromatic mixed solvent 50% Cellosolve acetate 19.8 3-ethoxypropylamine 30 Anionic surfactant 0.2 Stir and mix in the same manner as in Example 1. Example 3 Aromatic mixed solvent 49.8% Cellosolve acetate 10 3-methoxypropylamine 40 Anionic surfactant 0.2 Stir and mix in the same manner as in Example 1. Example 4 Aromatic mixed solvent 49.8% Cellosolve acetate 10 3-methoxypropylamine 40 Anionic surfactant 0.2 Stir and mix in the same manner as in Example 1. Example 5 Aromatic mixed solvent 29.4% Cellosolve acetate 12.5 Monoethanolamine 17.7 3-methoxypropylamine 14.8 Ethyl cellosolve 19.7 Water 1.6 Paraffin 1.6 Methyl cellulose 1.6 Dodecylbenzenesulfonic acid 1.1 Aromatic mixed solvent, cellosolve acetate and 3
- Stir and mix methoxypropylamine until homogeneous, then heat to 50-60°C, add other ingredients, and stir and dissolve. Example 6 Aromatic mixed solvent 29.4% Cellosolve acetate 12.5〃 Monoethanolamine 17.7〃 3-Ethoxypropylamine 14.8〃 Ethyl cellosolve 19.7〃 Water 1.6〃 Paraffin 1.6〃 Methyl cellulose 1.6〃 Dodecylbenzesulfonic acid 1.1〃 Example 5 similar to Prepare to. Example 7 Aromatic mixed solvent 39.4% Cellosolve acetate 15 Monoethanolamine 15 3-methoxypropylamine 10 Ethyl cellosolve 10 Water 5 Paraffin 1.6 Methylcellulose 3 Dodecylbenzenesulfonic acid 1 Same as Example 5 Prepare in the same way. Example 8 Aromatic mixed solvent 39.4% Cellosolve acetate 15 Monoethanolamine 15 3-ethoxypropylamine 10 Ethyl cellosolve 10 Water 5 Paraffin 1.6 Methyl allrose 3 Dodecylbenzesulfonic acid 1 Example 5 and Prepare similarly. (Example of use) The results of the peeling test using the coating film stripping agent of each of the examples above are collectively shown in Table 1 below. The dipping method was used for the samples of Examples 1 to 4, and the coating method was used for the samples of Examples 5 to 8. 1) Immersion test method: After applying various paints three times to a slate plate or iron plate, the sample piece is left for about one month. This sample piece is immersed in the peeling agent to be tested, and the time until peeling is measured.

[Table] −: Not tested.
(Effects) As detailed above, the present invention has an important meaning in the coating industry by being able to provide a coating film stripping agent that has excellent stripping ability and is safe.

Claims (1)

_[ Claims] _1. As _an essential component: Aromatic hydrocarbons represented by
(b) General formula [Formula] (wherein R represents a C ₁ to C ₄ alkyl group or a benzyl group,
represents either the atomic group _-C2H4- or _-C2H4 -O- _C2H4 ) _and (c) ω _- lower _alkoxy -lower alkylamine. 2
~40%. 2. The composition contains within 30% of (d) the general formula R-O-X-OH as an auxiliary component (wherein R represents a C ₁ to _{C 4} alkyl group or a benzyl group, and X is -C ₂ H ₄ -or-
The composition according to claim 1 _, comprising a glycol ether represented by _C2H4 - _O - _C2H4 . 3. The composition of claim 1, wherein the composition comprises 0.1 to 5% of (e) anionic surfactant as an auxiliary ingredient. 4. The composition of claim 1, wherein the composition contains up to 20% (f) water as an auxiliary ingredient. 5. The composition of claim 1, wherein the composition contains up to 40% of (g) mono-lower alkanolamine as an auxiliary ingredient. 6. The composition contains as auxiliary ingredients (i) an evaporation inhibitor;
(h) The composition according to claim 1, which comprises a thickener. 7. The method according to claim 6, wherein the evaporation inhibitor and the thickener are paraffin wax and methylcellulose, respectively, and the amounts thereof are 0.5 to 2% and 1 to 5%, respectively, in the composition. Composition.