JPH0349677B2 - - Google Patents

Description

[Detailed description of the invention]

B. Purpose of the Invention Industrial Field of Application The present invention relates to a coating agent for preventing spatter generated during arc welding of steel materials from adhering to base materials around welding, that is, a welding spatter adhesion prevention agent. It is. Conventional technology and its problems Traditionally, sputter adhesion prevention agents for welding have been used in two types: a direct coating type that leaves the coated film after welding and coats the paint directly over it, and a thinner that removes the coated film after welding. There is also a degreasing type that removes fat by degreasing with alkali, acid, etc. The present invention relates to the latter cleaning type spatter adhesion preventive agent, which can be classified into three types as shown below, each of which has its own drawbacks. The first type is talc, calcium carbonate,
It is a dispersion type that is mainly composed of inorganic powders such as magnesium carbonate and titanium oxide, and is dispersed in a hydrogen solvent with the addition of a thickening agent. Powders are scattered during cleaning, causing environmental degradation, and furthermore, cleaning waste liquid is difficult to dispose of. The second type consists of silicon as the main component, which is dissolved in a solvent or dispersed in water as an emulsion using a surfactant, and is called the silicon type and is used for stainless steel welding. Although this silicone type can be removed by pickling during scale removal, it has the disadvantage that if pickling is carried out for a long time, the silicone film will re-deposit, resulting in uneven removal. Furthermore, the third type is polyvinyl alcohol,
This method uses a water-soluble resin such as polyethylene glycol, but this has the disadvantage that the welding heat causes parts of the resin to become carbonized, and these carbonized parts are difficult to remove. In some cases, poor adhesion occurs. The present invention was made with the aim of developing a spatter adhesion prevention agent that does not have the above-mentioned problems.It can be easily removed in the cleaning process without increasing the number of conventional work steps, and does not cause problems in subsequent processes. Leave nothing behind.
The purpose of the present invention is to provide a novel spatter adhesion prevention agent that does not deteriorate the working environment, has good heat resistance, and improves the original spatter adhesion prevention effect. B. Structure of the Invention The structure of the present invention consists of alkali and alkaline earth organic acids having at least 6 carbon atoms and an aromatic carboxylic acid in which a carboxyl group is directly bonded to an aromatic ring. The gist of the present invention is a welding spatter adhesion inhibitor characterized by blending 5 to 50% by weight of one or more metal salts and 1 to 20% by weight of a surfactant. Measures to solve the problem As a treatment agent that is applied to steel materials before welding to prevent welding spatter from adhering to them,
After repeated studies on the combinations and amounts of various salts and surfactants, we found that aromatic acids that are organic acids with at least 6 carbon atoms and whose carboxyl group is directly bonded to an aromatic ring. A mixture of alkali and alkaline earth metal salts of group-based carboxylic acids (hereinafter often simply referred to as "organic acids") and surfactants in a predetermined ratio is decomposed by welding heat. They have discovered that it is an excellent spatter adhesion prevention agent that is difficult to remove and can be easily removed during the cleaning process (pickling, water washing, thinner washing). Examples of organic acids in the present invention include isophthalic acid, terephthalic acid, benzoic acid, acetylbenzoic acid, dithioterephthalic acid, β-oxynaphthoic acid, benzenehexacarboxylic acid, naphthalic acid,
Examples include trimellitic acid and gallic acid, and alkali and alkaline earth metal salts (hereinafter often simply referred to as "organic acid salts") of these acids, such as sodium, potassium, lithium, calcium, magnesium, etc. The metal salt becomes the organic acid salt as an essential component of the present invention. Since the organic acid in the present invention is an aromatic carboxylic acid, the number of carbon atoms is naturally 6 or more, but
General organic acid salts with a carbon number of 6 or more are difficult to decompose due to welding heat and have a good spatter adhesion prevention effect, but they cannot be used very close to the weld bead (within approximately 10 mm).
Merely having a large number of carbon atoms is inappropriate in the high-temperature region of be. The reason for this is that organic acid salts under the above conditions have the characteristic that they decompose and sublimate immediately after melting in a high temperature region without producing carbides, and can be easily removed by cleaning in the post-process (especially by cleaning with thinner). be. That is, aliphatic carboxylates and aromatic carboxylates in which the carboxyl group is not directly bonded to an aromatic ring carbonize and adhere in a high-temperature region, resulting in poor cleaning performance with thinner. The amount of this organic acid salt is 5 to 50% by weight.
If the blending amount is less than 5% by weight, prevention of spatter adhesion will be insufficient. On the other hand, if the blending amount exceeds 50% by weight, welding defects such as blowholes and pits are likely to occur when it enters the weld bead, making it unsuitable. As the surfactant in the present invention, any of nonionic, anionic, cationic, and amphoteric surfactants can be used, but nonionic surfactants often yield preferable results. Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene alkyl phenol ethers such as polyoxyethylene nonyl phenol ether, and polyoxyethylene alkyl phenol ethers such as polyoxyethylene monostearate. Examples include ethylene alkyl esters, polyoxyethylene sorbitan monoalkyl esters such as polyoxyethylene sorbitan monolaurate, oxyethylene oxypropylene block polymers, and the like. Examples of anionic surfactants include alkyl carboxylate fatty acid soaps such as rosin soaps,
Examples include alkyl sulfates such as sodium dodecylbenzenesulfonate, alkyl alcohol sulfate ester salts, and alkylmethyl taurate. Further, as the cationic surfactant, dialkyldimethylammonium chloride, polyoxyethylene alkylamine, etc. can be used, and as the amphoteric surfactant, dimethylalkylbetaine, etc. can be used. The amount of this surfactant must be in the range of 1 to 20% by weight; if it is less than 1% by weight, the organic acid salt will form a powdery coating when dried and will not adhere to objects such as base materials. This results in the disadvantage that the particles are scattered all over the place. On the other hand, if this amount exceeds 20% by weight, carbides are likely to be formed due to welding heat, and these carbides are difficult to remove by cleaning. The organic acid salt and surfactant in the present invention are mixed and dissolved in an appropriate solvent within the above concentration range, and the solvent is not particularly limited, but
Water or water-soluble alcohols are preferred, and examples of the water-soluble alcohols include methanol, ethanol, isopropanol, ethylene glycol,
Glycerin and derivatives thereof can be used. In addition, when actually applying the spatter adhesion prevention agent of the present invention, appropriate rust preventive agents, thickeners, leveling agents, coloring agents, fragrances, etc. may be added to the extent that the performance is not impaired according to the conditions of use. It may be used in combination with addition. Function The present invention has the above-mentioned structure, and the use of alkali and alkaline earth metal salts of aromatic carboxylic acids in which the carboxyl group is directly bonded to the aromatic ring has high heat resistance, and the weld bead Around (about 10
It does not decompose due to welding heat at a distance of more than
It decomposes and sublimates without carbonizing in the high-temperature range (within 30%). Moreover, the surfactant blended in an appropriate amount with this organic acid salt forms a uniform film that adheres to the welding base material, which reliably prevents spatter from adhering to steel materials, etc. It has the effect of eliminating the causes of rust and appearance defects after painting. Furthermore, the main component of the inhibitor of the present invention is soluble in water, acid, thinner, etc., and it does not leave any carbides, which can be easily removed in a cleaning process after welding, so it does not leave any problems in subsequent processes and is easy to work with. It also has excellent environmental friendliness. Example 1 A processing agent having the following composition was prepared. Sodium benzoate 5% by weight Polyoxyethylene oleyl ether 15% by weight Water 80% by weight Example 2 A processing agent having the following composition was prepared. Calcium benzoate 10% by weight Polyoxyethylene oleyl ether 10% by weight Water 80% by weight Example 3 A processing agent having the following composition was prepared. Sodium benzoate 40% by weight Polyoxyethylene oleyl ether 3% by weight Water 57% by weight Example 4 A processing agent having the following composition was prepared. Sodium terephthalate 10% by weight Polyoxyethylene lauryl ether 10% by weight Water 80% by weight Example 5 A processing agent having the following composition was prepared. Sodium paraoxybenzoate 10% by weight Polyoxyethylene nonyl phenyl ether
10% by weight Colorant 0.02% by weight Water 79.98% by weight Example 6 A processing agent having the following composition was prepared. Sodium β-oxynaphthoate 10% by weight Polyoxyethylene lauryl ether 10% by weight Ethanol 6% by weight Rust inhibitor 0.1% by weight Water 73.9% by weight Comparative Example 1 A treatment agent having the following composition was prepared. Sodium benzoate 1% by weight Polyoxyethylene oleyl ether 25% by weight Water 74% by weight This comparative example is an example in which the amount of organic acid salt is too small and the amount of surfactant is too large. Comparative Example 2 A processing agent having the following composition was prepared. Sodium benzoate 60% by weight Polyoxyethylene oleyl ether 1% by weight Water 39% by weight This comparative example is an example in which the amount of organic acid salt is too large and the amount of surfactant is too small. Comparative Example 3 A processing agent having the following composition was prepared. Sodium acetate 10% by weight Polyoxyethylene nonyl phenyl ether
10% by weight Ethanol 6% by weight Water 74% by weight This comparative example is an aliphatic example. Using the above-mentioned nine types of treatment agents, each was applied to the welding base material by brush coating, and a welding test was conducted under the following welding conditions. Welding conditions Carbon dioxide gas arc welding A steel plate with a thickness of 9 mm was welded with a T-shaped fillet Welding current: 300 A Arc voltage: 32 V Welding speed: 40 cm/min Wire diameter: 1.2φmm Gas flow rate: 20/min Evaluation Number of spatters attached in 100 ^cm2 after welding,
The number of pits generated was investigated for each treatment agent, and the water washability and thinner washability were tested. These results are shown in Table 1.

【table】

[Table] In the table, "Good" means that there is no carbide and the cleaning performance is good, "Bad" means that the area around the bead is carbonized and cannot be removed even with cleaning, and "Bad" means that the processing agent itself is difficult to remove. Each shows that. From this table, it can be seen that the treatment agent of the present invention has excellent spatter adhesion prevention properties and also has suitable cleaning properties. Comparative Example 1, which contains less organic acid salt and more surfactant, has a lot of spatter and has extremely poor cleaning performance, while Comparative Example 2, which contains more organic acid salt and less surfactant, has welding defects. is becoming more likely to occur. Furthermore, in Comparative Example 3, which used an aliphatic type resin having a small number of carbon atoms, the effect of preventing spatter adhesion was greatly reduced. C. Effects of the invention The effects of the invention are listed below. (a) It is a highly heat resistant spatter adhesion prevention agent,
It has excellent spatter adhesion prevention properties, does not directly generate paint, and is easily removable by washing with water. (b) In terms of work, it does not increase the number of man-hours compared to conventional methods and is more efficient. (c) It does not make the work environment subdued due to powder scattering, and works synergistically with the effect of (b) to greatly improve work efficiency. (d) Since it is a processing agent that can be easily removed during the cleaning process, it does not leave any problems in subsequent processes. As mentioned above, the sputter adhesion prevention agent of the present invention has various excellent effects.Since there is no adhesion of spatter and no residual treatment agent, there is no cause of rust or poor appearance after painting steel materials, and there is no need to weld steel materials. This makes it extremely useful for technology.

Claims (1)

[Claims] 1. One or more alkali and alkaline earth metal salts of an aromatic carboxylic acid, which is an organic acid having at least 6 carbon atoms and whose carboxyl group is directly bonded to an aromatic ring, as an essential component. 5 to 50% by weight, and 1 to 20% by weight of surfactant,
A welding spatter adhesion inhibitor characterized by containing the following.