JPS62263893A - Corrosion preventive method for weld line - Google Patents

Abstract

PURPOSE:To provide excellent corrosion preventive performance to the weld line of a metallic base material and to permit easy stripping by sticking self-adhesive tapes at specific intervals to the metallic base material along the weld line thereof and coating a corrosion preventive paint thereon. CONSTITUTION:The self-adhesive tapes 3 formed by impregnating an oil-resistant synthetic or synthetic resin self-adhesive agent to a glass fiber mat are intermittently stuck at the intervals within 500mm, to the metallic base material 3 along the weld line 2 thereof and the corrosion preventive paint 4 is coated thereon. The corrosion prevention of the weld line of the metallic base material is thus executed by the corrosion preventive coated film which can be easily stripped.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a corrosion prevention method for welding lines of metal base materials.

(Prior Art) According to the Fire Service Act, regular inspections of oil tanks are required to be carried out once every five to seven years, depending on the capacity of the tank. At that time, when inspecting the weld line, it is necessary to peel off the anticorrosion coating coated on the weld line. Conventionally, the anti-corrosion coating applied to the weld lines of the metal base material of the tank was treated by kerating or blast polishing. However, with the recent development of anti-corrosion paints, long-lasting F7J anti-corrosion paints have become available, and particularly high-performance Glass 7 Lake (th II Katamono) has been developed. However, after the rise of Las 7 Lake Lining, the coating film became extremely strong.
Moreover, the floor is indented in the convex part of the gate on the tangent line, making it extremely difficult to peel it off. This requires a significantly large number of man-hours and a good construction period, which poses an economical problem.

There, the paint film was immersed in oil etc. for 5 to 7 years.
One horn that maintains corrosion resistance at least for a year, flff during regular inspections! There has been a strong demand for anti-corrosion methods using paint films that can be peeled off. Nrikon for this purpose? A method was used in which anti-corrosion paint was applied after coating the weld line with a separation material made of 3-glue, but in this case, blistering occurred in the paint film after about a year. This is due to the fact that moisture builds up and pushes the coating film between the coating film and the release agent layer due to water vapor diffusion, resulting in close contact between the coating film and the release agent layer.

In addition, if anti-corrosion paint is applied to -1- where a polyethylene tape is pasted to F-weld line I-, the interface between the sheet and the anti-corrosion paint is not in close contact and moves, causing cracks in the paint film. tends to occur.

Historically, even when moisture-proofing treatment was applied to Lr-WL fiber or paper as a base fabric and adhesive tape was pasted on the weld line and anti-corrosion paint was applied, water vapor with small particle size could enter the tape through the anti-corrosion paint film, and The base fabric deteriorates over the course of a year or two due to bacteria and other factors, and when it comes time to remove the tape, it easily cuts, making the process difficult.

(Problems to be Solved by the Invention) The purpose of the present invention is to provide a corrosion-proofing method for welding lines of metal substrates using an anti-corrosion coating that has excellent anti-corrosion performance and can be easily peeled off during periodic inspections. It is about providing.

Another object of the present invention is to provide a corrosion protection method for welding wires of metal materials coated with an anticorrosion coating film that has excellent anticorrosion performance even when exposed to extremely corrosive substances.

(Means for Solving the Problems) The present invention provides adhesive tape made by impregnating a plus fiber mat with an oil-resistant synthetic rubber-based or synthetic O (fat-based adhesive) along the welding line of a metal base material for 50 minutes. (It pertains to a corrosion prevention method for welding lines, which is characterized by pasting intermittently at intervals of 1 mm or less, and painting an anticorrosive paint on it.

To explain the present invention using drawings, tIS3 is a cross-sectional view of a metal base material having a welding line that has been anti-corrosion treated by the method 1- of the present invention, where 1 is the metal base material, 2 is the welding line, and 3 is an adhesive tape. , 4 indicates an anticorrosive coating. In the present invention, as shown in Figure #IJ2, adhesive tapes are intermittently pasted along the weld line of the metal Jy material at intervals of less than 500161^ between adjacent adhesive tapes. ; For example, the weld line of a metal base material such as an oil tank may be pre-scorched or blasted to polish it, depending on the safety. An adhesive tape made by impregnating a plus fiber mat with an oil-resistant synthetic rubber-based or synthetic fat-based adhesive is pasted along this welding line. Examples of oil-resistant synthetic rubbers include chloroprene, nitrile rubber, urethane rubber, epichlorohydrin rubber, acrylic rubber, polysulfide rubber, etc., and examples of synthetic resins include polyvinyl ether, polyvinyl butyral, polyacrylic ester, coumaron indene resin, polybutene, etc. ≠ can be given. You can also use a mixture of these systems. In the present invention, these oil-resistant synthetic rubber-based or synthetic (3) oil-based adhesives are applied to about 50 to 600 H/
An adhesive tape is made by impregnating a 1n' plus fiber mat.

In addition, if the back of the adhesive tape is not processed with fluorine-based rubber or resin, silicone-based rubber, or polyolefin-based resin such as polyethylene or polypropylene, The adhesion between the adhesive tape and the anti-corrosion paint is strong and the anti-corrosion film performance is excellent, making it resistant to cracking and cracking.In addition, the plus fiber mat base fabric is water resistant, chemical resistant, and bacteria resistant. In addition to this, there is no need to worry about cutting as it has high strength when peeled off.Also, it is desirable that the thickness of the above-mentioned Karasagi tape is approximately 50 to 500μ. If it exceeds it, it will not follow the unevenness of the welded part -1, and it is also unfavorable economically. -B, if it is less than 50 μm, the strength will be low (and it will be difficult to work at the time of peeling).1- Width of the adhesive tape Since the weld line for tanks, etc., which is usually a bundle for periodic inspection, is 100+aIA to 30 Ova Tl1 width, it is desirable to cut it to a width equal to or wider than this.Also, the length of the weld line is Usually 1 piece II
T+ to 100 yams, but if it is more than ]Oaa, it is preferable to divide the tape into several parts and apply it, for example, 5 to 1
It is preferable to apply tapes having a length of 0... with a tape application interval of 500 mm or less. If the interval is larger than this, the area to which no tape is attached will increase, and the number of steps required to remove the coating on this surface will increase, resulting in inefficiency. - The reason why the tape is pasted discontinuously at intervals is to ensure that even if moisture were to be deposited at the bottom of the tape for a long period of time, it would be suppressed locally. Note that if the quality of the weld line is 10 or less, it is not necessarily necessary to paste it discontinuously.

In the present invention, anticorrosive paints include, for example, epoxy, urethane, acrylic, unsaturated polyester resin (based on fat, etc.) and paints containing Plus 7 Lake. Application of anticorrosive paints can be done by brushing, spraying, or rolling. Coating or other known methods may be used, and it is optional to apply a brimer paint as an undercoat.

(Example) A detailed explanation will be given below using examples.

Example 1 Using two SS-41W4 boards with a thickness of 6m+n, the length is 1,
Prepare 6 base materials that have been welded together with 000mm welding. Each of these base materials was sandblasted to meet the Swedish standard S.
Polish to a2.5.

Il: Various adhesive tapes shown in Table 1 are attached. In addition, as control samples, samples without adhesive tape and silicone (M-phase system release material (Shin-Etsu Silicone K)
A comparison was also made after applying S702).

In addition, for No. 5 and 6, the width is 100 [lll11.300
An adhesive tape was obtained using a plus fiber of g/re2 as a base fabric.

Next, apply vinyl ester (3 (phase primer) to a thickness of 20 μm and leave it for 4 hours, then add 7 lakes (particle size 2
00μ) 40 parts by weight)17. Add 30% of anti-corrosive paint
The entire surface was coated to a thickness of 0μ and cured at room temperature.

After each sample was left for 3 days, it was immersed in a heavy oil tank controlled at 60°C, and taken out after 36 months.

Peeling speed of coating film of each weld line and metal base material 5S-41
The rusting situation was inspected. The results are shown in Table 2.

Sample No. 006 showed the best results.

Tables 1 & 2 Example 2 The bottom of a 60'C waste oil tank was sandblasted in advance, and 450 g/m2 was applied on the weld line. %S I OO+ made by impregnating 1 piece of plus fiber base fabric with chloroprene rubber
An adhesive tape with a thickness of 300 μm was attached as described in No. 3 &. Apply the brimer paint made of this -1-1 vinyl ester resin to the entire surface of the 4'7 area of 30μ,
Furthermore, a 7-volume vinyl ester resin paint was applied to each unit to a thickness of 200 μm. In addition, a sample to which no adhesive tape was attached was also compared as a Huntroll sample, and the corresponding part of the weld line after 65 years was inspected, and the results are shown in Table 4. In addition, sample No. in Table 1, sample No. 7 in Table 3
The peeling speed of the control sample was measured using a sandblasting machine under the conditions of /7: diameter) Lnm, injection angle of 70-80°, injection distance of 40ce*, and injection source pressure of 7kg/'CII+ 2. did.

Table 3 No. 4 & (Effects of the Invention) The present invention has excellent anti-corrosion performance, and can be used to weld metal substrates with an anti-corrosion coating that will easily peel off during periodic inspections, etc. [Corrosion protection of wire] Two methods are provided.

The anti-corrosion method of the present invention can be applied to, for example, tanks for hazardous materials such as solin, navel, cut, light oil, 1N oil, methanol, asphalt, natural gas, and liquefied RI oil. [of maintenance management] is effective against fire.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a metal base material having a weld line that has been subjected to anti-corrosion treatment according to the T method of the present invention, and Figure 2 is a state in which adhesive tape is pasted at intervals along the weld line of the metal base material. Show the diagram. (hereinafter ``-) Patent client Toyo Rubber Co., Ltd. Representative Patent attorney + 111 Village Yokobue 1 diagram

Claims (2)

[Claims] (1) Adhesive tape made by impregnating a glass fiber mat with an oil-resistant synthetic rubber-based or synthetic resin-based adhesive is applied intermittently at intervals of 500 mm or less along the weld line of the metal base material, A method for preventing corrosion of weld lines, which is characterized by applying an anti-corrosion paint on the weld line. (2) The anticorrosion method according to claim 1, in which the back side of the tape is not treated with a fluorine-based, silicone-based, or polyfin-based mold release agent.