JPS61132293A - Adhesion preventing medium of welding spatter - Google Patents

Abstract

PURPOSE:To show an excellent effect in preventing a rust and spatter adhesion by making a welding spatter adhesion preventing medium from the water insoluble acrylic ester or metacrylic ester polymer body resin emulsion of specified composition. CONSTITUTION:It is the preventing medium from the adhesion of welding spatters containing 3-50wt% lower alkyl alcohol and consisting of the water insoluble acrylic ester or metacrylic ester polymer body resin emulsion of 3-50wt% solid part resin. By coating this welding spatters adhesion preventing material on the part to be welded of a steel material prior to the welding an elaborate film is formed and the spatter adhesion preventing effect excellent at welding time having an excellent rust prevention effect is brought on.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a weld spatter adhesion prevention agent used during welding work of steel materials.

(Prior Art) Conventionally, as a method for preventing the adhesion of welding spatter, manual operation using a scaling tool or the like has been used.

However, this method has disadvantages in terms of work time, work efficiency, worker fatigue, etc.

are doing. Further, there are the following examples of treatment agents that are applied to the periphery of the welded parts of steel materials to prevent spatter from adhering. For example, a paint-like spatter adhesion prevention agent containing a synthetic resin such as a phenol type, an alkyd type, a polyurethane type, a urea type, a melamine type, and an organic solvent (Special Publication No.
Synthetic resins are dissolved in solvents, such as sputter adhesion prevention agent (JP-A-52-44745), which is made by adding composite sintered powder of calcium oxide and ferric oxide to 129L alkyd resin, or they are made heat resistant. For this purpose, inorganic fillers are added. Therefore, when these compositions are used, problems such as fires caused by scattering of organic solvents during coating and deterioration of the working environment due to odors occur. On the other hand, in order to solve the above-mentioned problems, there is a sputter adhesion prevention agent using nonflammable water as a solvent. For example, a paste-like spatter adhesion prevention agent made by blending chalk, talc, water-soluble phenolic resin, and surfactant (Special Publication No. 46)
-13810), a sputter adhesion prevention agent mixed with a surfactant, a rust preventive, a monohydric alcohol, and water (Special Publication No. 52-
23899), a sputter adhesion prevention agent made by solubilizing a specific alkyd resin or acrylic resin in water together with a compatibilizer (Japanese Unexamined Patent Publication No. 57-131270).

(Problems to be Solved by the Invention) In welding, it is important that the surface to be welded is not rusted, and if it is rusted, problems such as a decrease in welding strength will occur. In this regard, although the above-mentioned spatter adhesion prevention agent using water as a solvent has the function of preventing spatter adhesion to steel materials, since it is water-soluble, the coating film tends to retain water, so it is difficult to prevent spatter from forming before welding. It rusts and has a negative effect on welding.

In addition, among the above-mentioned sputter adhesion preventive agents, those containing fillers have a rough coating surface, so when painting the surface of the material after welding, it is necessary to remove the spatter adhesion preventive agent.

The present invention prevents adhesion of spatter by applying it to the part to be welded, prevents rust from forming with the formed coating film, and further prevents adhesion of welding spatter so that it can be painted without removing the anti-spatter agent after welding. The purpose is to provide an inhibitor.

(Means for solving the problem) As a result of extensive research, the inventor has found that a specific acrylic 41
4 When a composition made by adding a specific alcohol to a fat emulsion is applied to the part to be welded, a secret film is formed, which has a good spatter adhesion prevention effect, has anti-corrosion properties, and does not need to be removed after welding. The present invention has been completed by discovering that it is possible to coat the surface of the surface of the surface of the surface of the surface of the surface of the surface. That is, the present invention provides a method for welding spatter adhesion made of a water-insoluble acrylic ester or methacrylic ester polymer resin emulsion containing 3 to 50% by weight of lower alkyl alcohol and having a resin solid content of 3 to 50% by weight. It is an inhibitor.

The anti-adhesive agent of the present invention can be produced, for example, by adding alcohol and, if necessary, water to an acrylic ester or methacrylic ester polymer resin emulsion.

Such acrylic ester or methacrylic ester polymer resin emulsions include, for example, methyl acrylate,
Acrylic acid alkyl esters such as ethyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate;
Methyl methacrylate, ethyl methacrylate, en-butyl methacrylate, methacrylic tan alkyl esters such as 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-methacrylate
A homopolymer or copolymer resin emulsion of two or more acrylic ester or methacrylic ester monomers such as hydroxyethyl, or a vinyl monomer that can be copolymerized with the above monomers, such as an aromatic vinyl compound such as styrene or vinyltoluene, α,β-unsaturated carboxylic acids, itaconic acid, maleic acid, fumaric acid and other α,β-unionated dibasic acids and their ester compounds; vinyl alcohol ester compounds such as vinyl acetate and vinyl propionate; acrylamide; Examples include copolymer resin emulsions with methacrylamide, vinyl chloride, etc. Further, these polymers and copolymers are preferably selected from those having a glass transition temperature (hereinafter abbreviated as FT?) of 0 to 50°C. If T2 is within this range, film forming properties will be excellent and the surface of the coating will be smooth. These polymer or copolymer resins must be water-insoluble; if they are water-soluble, they will not exhibit the rust-preventing effect before welding, which is the object of the present invention.

The above resin emulsion can be obtained by conventional emulsion polymerization. Emulsifiers used during emulsion polymerization include:
For example, conventional emulsifiers may be used, such as anionic emulsifiers such as sodium lauryl sulfate and dodecylbenzenesulfonate, or nonionic emulsifiers such as polyoxyethylene nonyl phenyl ether, oxyethylene oxypropylene copolymer, and the like. In addition, as the polymerization initiator, ordinary radical polymerization initiators are used, such as organic peroxides such as benzoyl peroxide, persulfates such as ammonium persulfate and potassium persulfate, and azobisinobutyronitrile. etc. are typical examples, and redox catalysts used together with reducing agents such as potassium metabisulfite and sodium thiosulfate may also be used.

Examples of lower alkyl alcohols in the present invention include methanol, ethanol, and flobyl alcohol, and these may be used alone or in combination of two or more. The amount of alcohol is 3 to 50% by weight (all percentages below are by weight),
Preferably it is 5 to 30%; if it is less than 3%, the effect of alcohols on accelerating the drying speed during film formation is lost;
If it exceeds 0%, the acrylic clot emulsion will not be able to exist stably. Note that, if necessary, a low boiling point solvent such as methyl ethyl keto/etc. may be used together with alcohol. In addition, medium to high boiling point solvents such as cellosol, methylcellosorbul, butylcarpitol, xylene, benzyl alcohol, and propylene glycol may be added to improve the smoothness of the coating film.

The anti-adhesion agent of the present invention needs to have a resin solid content of 3 to 50%. If it is less than 3%, the coating film will become thin and will not have sufficient rust prevention effect. Moreover, if it exceeds 50%, the viscosity becomes high and coating properties deteriorate, making it impractical. The preferred range of resin solids is 5-30%.

In order to produce the anti-adhesion agent of the present invention, the required amount of the alcohol may be added to the resin emulsion, and the mixture may be stirred if necessary. The solid content of 1 oil removed in the resin emulsion is measured in advance, and finally adjusted with water so that the resin solid content concentration of the anti-adhesion agent falls within a predetermined range.

The anti-adhesion agent of the present invention can be applied by spraying or brushing before welding.
Apply it to the part to be welded in the usual way, dry it, and use it.

(Function) As described above, the welding spatter adhesion inhibitor of the present invention
By applying it to the part of the steel material to be welded prior to welding, it forms a strange film that has an excellent rust prevention effect and provides an excellent spatter adhesion prevention effect during welding. After that, without removing the film,
It was possible to paint over it. Especially water-insoluble acrylic acid esters or dimethacrylic acid esters. Since the main component is an emulsion of stell polymer or copolymer resin, it has good adhesion to steel materials (and the coating film has low hygroscopicity, making it even more effective in preventing rust).

(Example) Examples will be described below. Note that the preparation of the test pieces and the performance test were conducted in the following manner.

The resin solid content was measured according to the method for measuring dry residue specified in JISK-s4oo.

The stability of the anti-adhesive agent was evaluated based on the extent to which the emulsion separated into two layers after being allowed to stand for 60 days.

dryness The drying speed of the coating film after brush application was observed with the naked eye.

It was measured by the needle penetration method.

membrane smoothness The test piece was visually observed and judged.

11 vertical and horizontal cuts were made in the coating film of the adhesion strength test piece at 1u intervals at °C.
・After adhering the tape, the tape was carefully peeled off and the percentage of 100 pieces of tape that did not come off was shown.

The water resistance test piece was immersed in water for 48 hours, and the whitening state of the coating film was observed.

The rust development test pieces were left in an atmosphere of 20°C and 65% RH, and the state of rust generation was observed after one day and night and after seven days and nights.

A commercially available undercoat paint was applied to the paint film of the paintability test piece, dried, and the adhesion strength between the anti-adhesion agent paint film and the undercoat paint was measured according to the adhesion strength test described above. The surface condition was observed.

Spatter adhesion prevention Steel plates with a thickness of 10 mm are butted together to form a groove surface, a spatter adhesion prevention agent is applied to the steel plate surface, dried, and a low hydrogen welding rod is used to weld at a welding current of 150 A and a welding voltage of 30 V. ,
Manual welding was performed at a welding speed of 1'50 m x 1 minute. After welding, the number of spatter-attached sides per 100 u of welded area was measured.

In the following Examples and Comparative Examples, all parts, percentages, and ratios are based on weight.

Example 1 800 parts of water was placed in a 214 Turow flask equipped with a thermometer, reflux condenser, stirrer, and monomer charger, and the temperature was raised to 70° C. under a nitrogen stream. Sodium lauryl sulfate 5 as an emulsifier
1 part, 5 parts of potassium persulfate was added as a polymerization initiator, and to this were added 700 parts of styrene, 470 parts of butyl acrylate, and methacrylic l\J! 50 parts of mixed monomers were added dropwise into the flask continuously over a period of 3 hours. Thereafter, the reaction was further carried out at the same temperature for 2 hours to complete the polymerization. Furthermore, ammonia and dimethylethanolamine were added to pH 9.0.
And so.

The obtained acrylic resin emulsion has a resin concentration of 60%.
The viscosity was s, ooo centipoise, and T120°C.

Cono emulsion, water, methanol, and butyl cellosolve were mixed in the proportions shown in Table 1 to obtain a sputter adhesion inhibitor having a resin solid content of 45%. The performance of this anti-adhesion agent was as shown in Table 1.

Examples 2 to 6 and Comparative Examples 1 to 2 A sputter adhesion prevention agent was obtained in the same manner as in Example 1 except that the emulsion and water were in the proportions shown in Table 1 and the resin solid content was different. Their performance was as shown in Table 1. The anti-adhesion agent of Comparative Example 2, in which the solid content of resin exceeds 50%, had a high viscosity and could not be successfully applied to the steel plate, so further tests were not conducted.

&i1) Hrq=vya9h+-3iSashima7・Tameko4HisameExample 1 has poor rusting and spatter adhesion prevention properties, but Examples 1 to 6 which are within the scope of the present invention all have Excellent performance,
It can be seen that Examples 3 to 5 are particularly excellent.

Examples 7 to 11 and Comparative Examples 3 to 4 Sputter adhesion inhibitors were obtained in the same manner as in Example 3, except that the ratios of methanol and water in Example 3 are shown in Table 2. The performance was as shown in Table 2.

From Table 2, if methanol is less than 6%, drying performance becomes poor.
It is clear that when it exceeds 50%, the stability of the anti-adhesion agent deteriorates.

Examples 12 to 13 An anti-adhesion agent was obtained in the same manner as in Example 6, except that the alcohol was ethanol in Example 12 and isopropyl alcohol in Example 16 instead of methanol. The performance was as shown in the table.

Table 5 Examples 14 to 17 Acrylic resin or methacrylic resin emulsions were obtained in the same manner as in Example 1 except that the water and monomer compositions were as shown in Table 4 and the emulsifier was sodium dodecylbenzenesulfonate. The resin solid content and T1 were as shown in Table 4.

These acrylic resin emulsion/water, methanol,
Butyl cellosolve was mixed in the proportions shown in Table 4 to obtain a sputter adhesion inhibitor. These performances are shown in Table 4, and all were good.

Comparative Example 5 Resin solid content 20%, viscosity 500 centivoise, PH8,
A sputter adhesion inhibitor was obtained by mixing 50 parts of polyacrylic acid ammonium salt of No. 0, 10 parts of methanol, and 40 parts of water.

Performance etc. were as follows.

Viscosity (centivoise) 23 Resin solid content 10 Drying property Good coating smoothness Good adhesion strength 80/100 Water resistance Poor (completely dissolved) Rust resistance
After 1 day and night Slightly Yes After 7 days and nights Paintability 70/100 Spatter adhesion prevention property 12 (Effect of the invention) From the above, the spatter adhesion preventive agent of the present invention has an excellent rust prevention effect and has little spatter adhesion, which is of great significance. .

Claims (1)

[Claims] A welding spatter adhesion inhibitor comprising a water-insoluble acrylic ester or methacrylic ester polymer resin emulsion containing 3 to 50% by weight of lower alkyl alcohol and having a resin solid content of 3 to 50% by weight.