JPS58688A - Inner-surface lining metallic pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal pipe, such as a steel pipe, which has an inner surface lined with a resin and has excellent corrosion resistance, abrasion resistance, and water resistance.

Traditionally, steel pipes have been widely used to transport granular materials and fluids, and recently steel pipes have been used to transport soil, ore, and other granular materials at dam construction sites. Became. Therefore, even if the above-mentioned steel pipes are connected as they are to form a no. Tubes lined with polyurethane resin are commonly used.

However, since the polyurethane resin film has an extremely large water diffusion coefficient and permeability coefficient compared to other resin coatings such as polyethylene or C-based coatings such as natural rubber or synthetic rubber, polyurethane resin is simply used on the inner surface of the steel pipe. If only the lining is applied, moisture will permeate through the lining material #I during use, and will further permeate through the adhesive layer to reach the metal base, causing water to leak inside the pipe.
- Not only is there a risk of rusting, but there is also a risk that the adhesion of the lining film to the metal substrate will decrease and it will peel off. Therefore, as a countermeasure, the metal is coated with a resin or rubber that has relatively good water resistance. A method is adopted in which two lining layers are formed on the inner surface of the tube, one on top of which is then lined with polyurethane resin. Although this method can provide some effects, it is extremely expensive and is therefore not preferred in practice.

As a result of research aimed at solving the problems of the prior art as described above, the inventors of the present invention found that glass flakes, carbon, kaolin, mica talc, and graphite were used as penetration-resistant materials to prevent moisture from penetrating into polyurethane resin. However, even if the lining was oval and the entire surface was coated with polyurethane, the abrasion resistance and chemical resistance, which are the original characteristics of polyurethane resin, would deteriorate. I like it,
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So, as a result of further research, water has won multiple linings.

In order to prevent the inner surface of the tube from rusting even when it passes through the adhesive layer, it does not reach the metal base, and in order to prevent the inner surface of the tube from rusting, it was devised to form dissimilar metals M and L1 in advance by plating, etc., on the inner surface of the metal tube. , I hope to complete this invention.

That is, the structure of the present invention is characterized in that a metal coating* different from the metal is formed on the inner surface of the metal tube, and a polyurethane resin lining is applied to the surface of the metal coating via adhesive N. It is something.

Next, implementation of the present invention will be explained with reference to the drawings.

In Fig. 1, 1 is a steel pipe whose inner surface is to be lined with polyurethane resin, 2 is a composite film of metal such as zinc formed on the inner surface of the wire tube 1, and 6 is the surface of the metal coating 1!2. The adhesive layer 4 formed on the surface of the #adhesive layer 6 is a polyurethane resin compound formed on the surface of the #adhesive layer 6, and the inner lining metal tube of the present invention is constructed as described above. Manufactured by such a method.

After pickling and flushing the inner surface of the steel pipe 10, the inner surface of the core t
A metal coating 112 is formed by zinc plating or thermal spraying of a lead-aluminum mixture, and then the metal coating #2 is subjected to appropriate treatment as necessary, such as chemical conversion treatment. On the surface, an adhesive layer made of epoxy resin or the like that firmly adheres to the metal coating 2 and polyurethane resin is applied by brushing, flow coating, spraying, etc. to form an adhesive layer 3, and the adhesive By applying a polyurethane resin lining to the surface of the layer 3 by a conventional method, an inner lining S film in which a polyurethane resin coating 11 [4] is formed on the surface of the adhesive layer 3 can be obtained.

When water containing earth, sand, ore, etc. is poured into the internally lined steel pipe with the above-mentioned structure, the water permeates through the polyurethane resin coating 4 and further through the adhesive layer 3. However, ascites is blocked by the metal coating 2 and there is no risk of it reaching the metal base, so there is no risk of the tube 1 corroding from its inner surface.

Next, inner lining steel curvature specimens W1 and 1 with polyurethane resin lining omitted using a conventional method, and inner lining 111111ft-specimen IF2 according to the present invention. I-L
Here, each test tube was manufactured by the following method and the experiment was carried out.

Test tube 1 Gridplast the inner surface of a 150A steel tube, pour adhesive from one end of the tube while rotating it on an inclined rotary table, and
After applying it to the inner surface of the tube at a rate of 0 to 41H1/m, place the tube in a horizontal position! $111- Strain and rotate at low speed (about 60 rpm)
The adhesive layer is formed by curing or air drying for about 1 hour, and then the tube is preheated to 80°C, and the tube is coated with
A mixture of the base polyurethane prepolymer, which has been vacuum degassed at 80°C, and a rapid curing agent melted at 110°C in a ratio of 100:12 is poured into the f# amount required for the thickness of the lining S film to be 6M. The tube is rotated at high speed (approximately 300 rp
After assimilating with
By heating and aging for more than an hour, a thick polyurethane resin coating was formed on the surface of the adhesive layer.

Test tube 2 After pickling and flushing the inner and outer surfaces of the 150Am tube,
Zinc plating is applied by dipping the wire tube into a molten zinc bath and pulling it up to form a metal coating on both the inner and outer surfaces of the wire tube, and then a chemically formed part j1 is applied to the metal coating surface on the inner surface of the tube. ,
An adhesive layer and a polyurethane resin coating M were formed on the surface in the same manner as for test tube 1 (see FIG. 2).

Therefore, the above test tube 1.2 was subjected to the same conditions, that is, sand slurry concentration: 40 wt., flow rate: 3.5 m.7 sec, m.degree.
After conducting an experiment for about 1 year at 0 to 55°C, it was found that in test tube 1 manufactured using the conventional method, water partially penetrated into the interface between the polyurethane resin coating including the adhesive layer and the inside of the tube, causing the resin coating to deteriorate. It was observed that the resin coating was peeled off and rusted on the metal base surface, and the amount of wear of the resin coating was about α2W.
Similarly, water partially penetrated, but the metal base was protected by the metal coating and no sag occurred, and there was no difference in the amount of wear of the resin coating from that of Test Tube 1.

In addition, in the test '1121, a plating method was adopted to form the metal coating 1111 by dipping in spots, so a metal coating was formed on both the inner and outer surfaces of the tube, and the corrosion resistance of the outer surface of the tube was also improved. When forming the toilet material, it is possible to form it by electroplating, thermal spraying with our lead-aluminum mixture, coating with zinc powder, coating with #heavy metal, etc., and if the toilet material is corrosion-proof. good.

In addition, if a penetration resistance material layer is formed to prevent moisture from penetrating the adhesive layer in the test tube 21 and/or the adhesive layer 11i of the resin coating, the above-mentioned penetration of moisture and the resin coating may be prevented. You won't be bothered by peeling at all.

The lamp of the present invention is as described above, and the inner surface of gold*iir is
A metal material different from the above metal is formed, and a polyurethane resin lining is applied to the surface of the gold 1Ili coating via an adhesive layer to form a polyurethane resin covering, so it has corrosion resistance, abrasion resistance, It has excellent water resistance and is therefore suitable as a pipe used to transport water containing soil, ore, etc. If the metal coating #I is formed by zinc plating using Shinkai Dofuzuke, which was used for test tube 2, the metal coating III will be formed on both the inner and outer surfaces of the tube, and the corrosion resistance of the outer surface of the tube will also be improved.
Also, when transporting water, the water penetrates and reaches the metal coating on the inner surface, and even if the nuclear metal coating is damaged for some reason and the metal base is damaged, the chemically active zinc is attacked first. Since the metal base is protected, the service life of the pipe can be extended. In this embodiment, straight pipes have been mainly described, but it goes without saying that the present invention can also be applied to elbow pipes and irregularly shaped pipes with tee grooves.

[Brief explanation of drawings]

Both FIGS. 1 and 2 are sectional views showing embodiments of the present invention. 1... Steel pipe, 2... Metal coating, 6... Adhesive layer,
4...Polyurethane agent Yoshikuni Koizumi

Claims (1)

[Claims] The inner surface of the metal tube is characterized in that a metal coating different from the metal is formed and a polyurethane resin lining is applied to the surface of the metal tube via a adhesive layer.