JPH0329106B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composition for removing coatings, and more particularly, it can easily remove coatings from substrates (concrete, mortar, asbestos slate, plywood, decorative boards, etc.) while rapidly forming a drying film. The present invention relates to a composition that can be exfoliated from calcium silicate boards, pulp cement boards, etc.). Conventionally, many film removing agents have been known, such as those whose main component is a chlorinated hydrocarbon solvent, and those whose main component is a component that exhibits strong alkalinity. Chlorinated hydrocarbon solvents have been used for such purposes for quite some time, but they generally evaporate too quickly to simply apply them to a desired film and remove the film, so they cannot be used without incorporating various evaporation inhibitors. The effect of the remover disappears within a short period of time. Paraffin, alcohol, amine, etc. have been used as evaporation inhibitors, but their effects have not been as great. On the other hand, those whose main constituent is a component exhibiting strong alkalinity, such as those that use a large amount of sodium hydroxide, have a removal effect but are extremely dangerous. In particular, when removing old coatings applied to the walls of buildings, etc., there is a need for coating weight parts that maintain their effectiveness for a considerable period of time and are highly safe. The present invention has been made to solve the above-mentioned difficulties. That is, the present invention is directed to a film-removing method comprising a chlorinated hydrocarbon solvent as a main component, and a carboxylic acid-modified vinyl synthetic resin, a solid paraffin, a naphthenic acid salt, and, if necessary, tetramethylene oxide. It relates to a composition, and when this composition is applied to the coating to be removed,
After a certain period of time has elapsed, the coating can be easily removed together with the removal agent. Hereinafter, the configuration of the present invention will be described in detail. Examples of chlorinated hydrocarbon solvents include methylene chloride,
Examples include carbon tetrachloride, ethyl chloride, ethylene chloride, trichloroethane, trichloroethylene, tetrachloroethane, perchloroethylene, pentachloroethane, propylene chloride, trichloropropane, dichlorobutane, and dichloropentane.
Among these, methylene chloride, ethyl chloride, ethylene chloride, trichloroethane, trichloroethylene, tetrachloroethane, and perchlorethylene are easy to use in terms of cost, supply amount, etc. Next, examples of carboxylic acid-modified vinyl synthetic resins include acrylonitrile, vinyl chloride, styrene, acrylic esters, methacrylic esters, vinyl acetate, vinyl propionate, ethylene, propylene, vinyl ether, etc. alone or in combination. Polymer resin, phthalic acid, maleic acid,
A substance that has been internally or externally modified with a carboxylic acid such as fumaric acid. Furthermore, the naphthenate refers to a metal salt of naphthenic acid, and examples of the metal include lead, cobalt, manganese, zinc, copper, and aluminum. Furthermore, solid paraffin refers to a crystalline paraffin product separated from petroleum and purified, and has a melting point of 37.8 to 64.5°C. In addition, in the present invention, tetramethylene oxide may be blended for the purpose of imparting or improving the dissolving function of the remover. According to the inventors' estimation, the functions of the above-mentioned components in the present invention are that the chlorinated hydrocarbon solvent mainly acts to swell the film, and the carboxylic acid modified product of vinyl synthetic resin mainly acts to swell the film. Retention effect in the removable dry membrane for hydrogen solvents (action to prevent chlorinated hydrocarbon solvents from escaping by forming a dry membrane), solid paraffin mainly suppresses evaporation of chlorinated hydrocarbon solvents. (effect of raising the boiling point of chlorinated hydrocarbon solvents), naphthenate mainly has an early drying effect of carboxylic acid modified vinyl synthetic resin and a fluid adjustment effect of the remover, and tetramethylene oxide mainly has a film removal effect. Each acts by sharing the dissolving action (the action of improving the removal function by adding to the swelling action). As described above, according to the inventor's individual experiments with each component, it is presumed that each component exhibits its own unique properties, and when combined for the purpose of film removal, greatly improves its effectiveness. It is. The method for preparing the removing agent of the present invention is generally carried out as follows. 0.2 to 2 parts by weight of a naphthenic acid salt is blended with 100 parts by weight of a chlorinated hydrocarbon solvent and mixed well. When 3 to 25 parts by weight of a powdered vinyl synthetic resin modified with carboxylic acid is gradually added to the solution while stirring, the solution takes on a thixotropic viscosity. After about half an hour, 0.3 to 3 parts by weight of solid paraffin powder, either directly or previously dissolved in a hydrocarbon solvent, is added and mixed, and the mixture is easily dissolved. Additionally, in order to further increase the removal effect, tetramethylene oxide can be blended, and although tetramethylene oxide can be blended in any order, it is preferable to blend it with a chlorinated hydrocarbon solvent. It is best to start with a mixed solvent of and tetramethylene oxide. In this way, the removing agent of the present invention is prepared. The removing agent of the present invention is used by applying it to the surface of the organic film to be removed in an amount of approximately 0.5 kg/m ² or more. After several minutes to several tens of minutes, a thin dry film is formed on the surface layer of the remover. The chlorinated hydrocarbon solvent, which is the main component of the removal agent, swells the coating and penetrates the interface between the base material and the coating. In addition, tetramethylene oxide penetrates and absorbs the swelling action of chlorinated hydrocarbon solvents.
It is presumed that it imparts a dissolving action and exerts a stronger removal action. If too much of the carboxylic acid-modified vinyl synthetic resin is blended here, the workability of applying the remover will be poor, and if it is too little, the amount of coating applied to the film to be removed will be significantly reduced. . If there is too much naphthenate, the remover will gel and become impossible to apply, while if it is too little, it will be difficult to obtain the appropriate viscosity and the amount of coating applied to the film to be removed will decrease at once. . When solid paraffin is blended in excess, it often remains on the base material after removal, and the adhesion of subsequently applied coating materials, adhesives, etc. during the construction of decorative laminates becomes poor. When the amount is small, the effect of suppressing evaporation of the chlorinated hydrocarbon solvent is significantly reduced. If more than 20 parts by weight of tetramethylene oxide is added, the effect of the chlorinated hydrocarbon solvent will be reduced, and it may be dangerous due to its relative toxicity, so if it is added, the amount should be less than 20 parts by weight. There is a need. Examples are shown below. Example 1 Methylene chloride 100 parts Zinc naphthenate 0.5 parts Styrene-acrylate resin modified with maleic acid 5 parts The above components were mixed to obtain a thixotropic solution. Next, a mixture of 1 part by weight of kerosene and 1 part by weight of solid paraffin having a melting point of 40° C. is added to the above solution to obtain the coating removal composition of the present invention. This remover is applied using organic lysine (applied amount
1.3Kg/m ² ), the coating amount was approximately 0.7Kg/m ² and was applied uniformly with a brush. Further, it was applied uniformly with a brush at a coating amount of about 1.2 kg/m ² onto the surface of a sprayed tile (coating amount: 3 kg/m ² ) using an acrylic resin as a vehicle, which had also been applied for 5 years. After one hour, a thin dry film of the remover was formed on the surface of each remover, and both the organic ricin coating and the sprayed tile coating had softened and swelled. We also measured various physical properties of these materials. The results were as shown in Table 1 below. Example 2 A film removal composition was manufactured and tested based on Example 1, except that a maleic acid modified vinyl chloride resin was used as the carboxylic acid modified vinyl synthetic resin in Example 1. However, the removal effect was very good. Further, its various physical properties were measured in the same manner as in Example 1. This result will be described in Section 1 below.
Shown in the table. Example 3 In Example 1, 5 parts by weight of tetramethylene oxide was further added to produce a composition for film removal, and an experiment was conducted, and the removal effect was very good. Further, its various physical properties were measured in the same manner as in Example 1. The results are shown in Table 1 below. Comparative Examples 1 to 2 In Example 1, a film-removing composition containing no zinc naphthenate (Comparative Example 1) and a powder of vinyl chloride resin instead of a maleic acid-modified styrene-acrylate resin were used. The product used (Comparative Example 2) was manufactured. The results of the same experiment as in Example 1 using these are shown in Table 1 below. Experimental Example 1 Below, in order to make the features of the present invention more clear, the above Examples 1 to 3 and Comparative Examples 1 to 2 will be explained.
Experiments were conducted to measure the various performances of each composition. The results are shown in Table 1 below.
However, in addition to these compositions, Table 1 also lists the results of similarly measuring the performance of two control compositions. <Experimental method> Each test composition was treated with (a) organic lysine (applied amount
(1.3Kg/m ² ) surface (30cm x 30cm), and (b) surface of sprayed tiles (applied amount 3Kg/m ² ) using acrylic resin vehicle that has been applied for 5 years (30cm x 30cm).
cm), 0.7Kg/m ² in case of (a), 1.2 in case of (b)
Kg/m ² was applied. <Judgment method> One hour after applying each film removal composition, observe the surface condition, evaluate the difficulty of peeling with a metal scraper (spatula), and evaluate the condition after peeling with a metal scraper (spatula). The remaining status of the sample coating film was measured. <Composition for film removal used> A: Composition B of Example 1: Composition C of Example 2: Composition D of Example 3: Composition E of Comparative Example 1: Composition F of Comparative Example 2 : Control composition of methylene chloride alone G: Methylene chloride 100 parts by weight Vinyl chloride-vinyl acetate resin (not modified with maleic acid) 10 parts by weight <Measurement results> As shown in Table 1 below

[Table] In order to further clarify the characteristics of the present invention, the following experiment was conducted. The results are shown in Table 2 below. Experimental example 2 <Experiment method> i Raw materials used a: Methylene chloride (dichloromethane) (manufactured by Kanto Kagaku Co., Ltd.) b ₁ : Copper naphthenate (manufactured by Nacalai Tesque Co., Ltd.) b ₂ : Disodium succinate (manufactured by Nacalai Tesque Co., Ltd.) KK)
b ₃ : Calcium citrate (Nacalai Tesque Co., Ltd.)
b ₄ : Calcium tartrate (manufactured by Nacalai Tesque Co., Ltd.) b ₅ : Sodium dioctyl sulfosuccinate (manufactured by Wako Pure Chemical Industries, Ltd.) c ₁ : Maleic acid modified product of vinyl chloride-vinyl acetate copolymer resin (manufactured by Denki Kagaku Kogyo Co., Ltd.) Denka Vinyl "1000CK-2" manufactured by Denki Kagaku Kogyo Co., Ltd.) c ₂ : Maleic acid modified product of vinyl chloride-vinyl acetate copolymer resin (Denka Vinyl "1000LCH" manufactured by Denki Kagaku Kogyo Co., Ltd.) c ₃ : Ethylene-vinyl acetate copolymer resin Polymer resin (Movinyl “DM-200” manufactured by Hoechst Gosei Co., Ltd.) d: Solid paraffin (melting point 40°C) (Nippon Seiro Co., Ltd.)
e: Kerosene 2 composition (parts by weight)

【table】

[Table] 3 Procedure Place a into a polypropylene container with a capacity of 100 g. Gradually add b to the solution while stirring. While stirring the next solution, add c little by little. Next, a solution of d dissolved in e is added little by little to the solution while stirring. 4. Evaluation method Based on the properties of the finished composition, it is determined whether it can be used as a film removal composition.
(Viscosity too high to apply, good, viscosity too low to apply, etc.)

【table】

[Table] According to the above results, the present invention exhibits starch syrup-like thixotropic properties only when a combination of a chlorinated hydrocarbon solvent, a carboxylic acid-modified vinyl synthetic resin, solid paraffin, and a naphthenic acid salt is used. It can also be applied to a certain amount of thickness. Furthermore, these properties make it difficult for the chlorinated hydrocarbon solvent to volatilize, increasing the film removal effect. On the other hand, No. 9 uses a resin that has not been modified with carboxylic acid, and No. 3 uses a salt other than naphthenate.
~ No. 8 and No. 10 have high fluidity and flow on vertical surfaces, and cannot be applied thickly, so the chlorinated hydrocarbon solvent evaporates early, resulting in poor film removal efficiency.

[Brief explanation of drawings]

Figures 1 to 4 are drawings showing the results of measuring the performance of various paint film removing compositions.

Claims (1)

[Scope of Claims] 1. A film-removing composition comprising a chlorinated hydrocarbon solvent, a carboxylic acid-modified vinyl synthetic resin, solid paraffin, and a naphthenic acid salt. 2 Chlorinated hydrocarbon solvent, tetramethylene oxide,
A film-removing composition comprising a carboxylic acid-modified vinyl synthetic resin, solid paraffin, and naphthenate. 3 3 to 25 parts by weight of a carboxylic acid modified vinyl synthetic resin per 100 parts by weight of the chlorinated hydrocarbon solvent,
2. The film removing composition according to claim 1, comprising 0.3 to 3 parts by weight of solid paraffin and 0.2 to 2 parts by weight of naphthenate. 4 3 to 25 parts by weight of a carboxylic acid modified vinyl synthetic resin per 100 parts by weight of the chlorinated hydrocarbon solvent,
3. The film removing composition according to claim 2, comprising 20 parts by weight or less of tetramethylene oxide, 0.3 to 3 parts by weight of solid paraffin, and 0.2 to 2 parts by weight of naphthenate.