JPH0635174B2 - Liquid storage or transportation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid storage or transportation device such as a tank or a pipe, and more particularly to a liquid storage or transportation device made of a resin-coated metal material for anticorrosion.

[Conventional technology]

2. Description of the Related Art Conventionally, resin linings for the purpose of preventing corrosion and rust of metal materials have been widely used for liquid storage or transportation devices such as tanks, tanks, line pipes, mainly for various pollution control devices and chemical devices. However, as the performance of the resin lining, there is a phenomenon of permeation of environmental chemicals and moisture that come into contact with the coating layer into the lining coating layer, which causes corrosion of the underlying metal, and blister and peeling phenomena of the coating layer. That became a familiar problem. In particular, this permeation phenomenon is promoted under a condition where the temperature gradient is large, for example, the surface of the coating layer is in contact with a high temperature liquid, while the back surface of the base metal is in contact with a low temperature atmosphere. It is a serious problem for lining materials.

[Problems to be Solved by the Invention]

As one of the solutions to the above problems, it is known to use a lining material having a high penetration resistance and to use a lining material mixed with glass flakes, mica flakes or the like as a penetration resistance material. However, such a lining material can only slightly slow the permeation rate, and as a result, corrosion of the base metal due to permeation, swelling of the lining material, peeling, etc. occur in a relatively short time. I can not say. In addition, as another solution, a through hole called a vent hole is provided in the element metal, and the chemical solution or water that has reached the base metal through the coating layer is discharged from the vent hole through the interface between the coating layer and the base metal. There are known methods for preventing corrosion and the like. However, this method is not effective when the coating layer and the base metal are adhered, and can be applied only to the non-adhesive lining with a liner or sheet inserted, which is called loose lining. In order to maintain strength against resistance to feeding, etc., it must be thick, resulting in high cost in terms of cost, and poor workability in the construction of complicated shapes. In addition, it cannot be used for negative pressure, and there is a problem of strength reduction because a hole is made in the base metal.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a liquid storage or transportation device made of a resin-coated metal material capable of preventing the coating layer from swelling or peeling over a long period of time.

[Means for Solving the Problems]

As a result of intensive studies to solve the above problems, the present inventors have found the following matters. That is, the chemical liquid or water molecules that have permeated the resin coating layer are accumulated in the minute cavities that originally existed at the interface between the resin coating layer and the metal material ground, but at that time, extremely high pressure is generated. . When corrosion of the metal material surface occurs due to the accumulated chemical liquid or water, the product of the reaction causes a large change in volume and a high pressure is generated in the cavity. By the generation of these pressures,
The resin coating layer peeled off and became blistered. Therefore, when an intermediate layer having a porous structure having continuous pores is provided between the resin coating layer and the metal material ground, and the continuous pores of the intermediate layer are opened to the atmosphere, the resin coating layer and the metal material ground are separated. It is possible to prevent the generation of high pressure at the interface of, and it is possible to prevent peeling and blistering of the coating layer for a long time.

The present invention has been made on the basis of such findings, and in a liquid storage or transportation device composed of a resin-coated metal material obtained by coating a metal material substrate with a corrosion-resistant resin coating layer, the resin-coated metal material is As shown in FIG. 1, an intermediate layer 3 having a porous structure is provided between a resin coating layer 1 and a metal material ground 2.

The porous intermediate layer 3 used in the present invention has an infinite number of continuous pores. For example, the continuous pores are opened to the atmosphere by exposing the ends thereof to the atmosphere. The pore size should be as small as possible. These holes serve to capture and adsorb the chemical liquid or water that has permeated the resin coating layer 1 and prevent the chemical liquid or water from reaching the metal material base 2 and corroding it. Further, since the pores are continuous and open to the atmosphere, the pressure of the chemical liquid or water that permeates through the resin coating layer 1 and is accumulated in the intermediate layer 3 does not increase, whereby the resin coating layer 1 No peeling or blistering. Further, since the continuous pores form a moving path for the chemical liquid, water, etc. that has permeated the resin coating layer 1, even if the chemical liquid, water, etc. have permeated the resin coating layer 1 for a long period of time, the chemical liquid, Moisture and the like flow along the intermediate layer 3 as shown by the arrow A in the drawing and can exit the system from the end, and are trapped between the resin coating layer 1 and the metal material ground 2 to generate a high pressure. Therefore, the resin coating layer does not peel or swell even after long-term use. A vent hole (indicated by a chain double-dashed line 4 in the drawing) may be provided in the base metal in order to discharge the chemical solution, water and the like from the intermediate layer to the outside of the system. Normal,
The intermediate layer is firmly adhered to the metal material ground and the resin coating layer, but unlike the conventional loose lining, it is not bonded to one or both of the metal material ground and the resin coating layer. May be.

The thickness of the intermediate layer 3 having a porous structure in the present invention may be such that the chemical liquid, water and the like having permeated the coating layer can flow, and is usually selected to be about 0.1 to 1 mm. .

The material forming the intermediate layer having a porous structure is not particularly limited,
Various materials can be used, for example, foamed resin, thermal sprayed layer with many pores, sintered material, aggregate of fiber materials, or fabric impregnated with resin to the extent that pores remain.

Examples of the metal material of the metal material substrate 2 include mild steel, low alloy steel, stainless steel, non-ferrous metals such as aluminum, and alloys thereof. The form of the liquid storage or transportation device made of this metal material may be any form such as a pipe or a tank as long as it is used for liquid storage or transportation.

As the coating resin, fluorocarbon resin, polyethylene, polyester, epoxy, phenol, urethane, and any other resin conventionally used can be applied, and either thermoplastic or thermosetting resin may be used.

〔Example〕

Next, a specific example of the resin-coated metal material forming the liquid storage or transportation device of the present invention will be described.

Example 1 Alumina was sprayed on one surface of a steel plate of 80 × 80 × 3.2 ^t to form an intermediate layer having a porous structure of 300 μ, and polyethylene was powder-lined thereon to form a resin coating layer of about 1 mm. Formed. The resin coating material thus obtained is applied to a lining tester, and the peripheral end faces are exposed to the atmosphere.
Hot water at 60 ° C. was brought into contact with the resin coating layer surface and water at 30 ° C. was brought into contact with the other surface, the appearance was visually observed at each elapsed time, and the weight of the test piece was measured with a balance. In addition, the adhesive strength was measured before and after the test.

For comparison, a resin coating material (comparative example) obtained by powder-lining polyethylene on one side of a steel sheet was tested under the same conditions as above. The results are shown below.

(1) Change in Adhesive Force The change in adhesive force with time obtained by the above test is shown in the graph of FIG. As is clear from FIG. 2, the resin coating material (Example 1) having a porous layer of alumina sprayed on the underlayer (Example 1) did not lower the adhesive strength at all (up to 2720 hours). On the other hand, in the case of no porous layer (Comparative Example), the adhesive strength was almost lost in about 500 hours. When the resin coating layer was peeled off and the steel sheet surface was visually inspected, some rust was observed.

(2) Change in weight The result of measuring the change in weight of the test piece over time is shown in the graph of FIG. As can be seen from this graph, in the case of providing the alumina-sprayed porous layer, the initial weight increase was fast, but it was about 3.5 mg / cm ² constant, and there was almost no change thereafter. On the other hand, in the case where there is no porous layer, the weight increases linearly on a logarithmic graph, and even after the blistering occurs in about 1300 hours, the weight continues to increase similarly, which leads to an increase in the blistering.

As for the above, first, in the case of the porous layer, the permeated water quickly sorbs in the pores, so the initial weight increase is fast, but after saturation in the pores, it is gradually discharged from the end surface of the test piece. It is speculated that the increase in weight will stop because of this. Normal,
The saturated water absorption of a 1 mm-thick polyethylene single sheet is about 0.2 mg / cm ^2, so it is about 3.3 mg / c.
It is considered that a water content of about m ² (3.5-0.2 = 3.3) is contained in the alumina porous layer. As described above, in the test piece according to Example 1, since the end surface of the porous layer is exposed to the atmosphere and the water in the porous layer freely oozes out, the water is left in the resin coating layer for a long period of time. Even if it permeates and continues to penetrate into the porous layer, it is presumed that moisture exceeding a certain amount is discharged to the outside, and thus the adhesive strength does not decrease and blistering does not occur until the end of the test.

Example 2 A polyethylene coating layer of about 1 mm was formed on one surface of a steel plate of 80 × 80 × 3.2 ^t through a foamed polyethylene layer having continuous pores of 0.5 mm. Example 1 was applied to this resin coating material.
When the same last was applied, the adhesive strength was hardly reduced even after 600 hours had passed.

Example 3 A glass cloth having a thickness of about 300 μ was placed on one surface of a steel plate of 80 × 80 × 3.2 ^t , and powdered polyethylene was placed on the glass cloth and heated and melted to form a polyethylene coating layer. Fine pores between the glass fibers are left in the portion including the glass cloth in the coating layer, which constitutes a porous intermediate layer. When the resin coating material was tested in the same manner as in Example 1, the adhesive strength was hardly reduced even after 600 hours had passed.

Example 4 On one surface of an 80 × 80 × 3.2 ^t steel plate, a primer having a mixing ratio of alumina powder and a vine bar having an alkyl silicate as a main component in a weight ratio of 70:30 was applied to the surface to be coated of about 100 μ. After baking, it was heated and powdered polyethylene was placed on it and melted to form a polyethylene coating layer. The primer portion of this coating layer is porous, leaving fine pores. When this resin coating material was tested in the same manner as in Example 1, there was no decrease in adhesive strength even after 600 hours had passed.

Example 5 As shown in FIG. 4, pipe size 150A, length 200m
The inner surface and the flange surface of the steel pipe 6 with flanges at both ends of m were subjected to grit blasting, and about 300 μ of alumina was sprayed to form an intermediate layer (porous layer) 7 having a porous structure. Then, after heating the steel pipe 6 in an electric furnace at about 300 ° C.,
The resin coating layer 8 was formed by lining the powdered polyethylene with heat by about 1 mm. The end surface of the porous alumina layer 7 is exposed at the flange surface as shown in the figure.

In addition, a pipe of the same size was prepared by subjecting only the grit blast to the inner surface and polyethylene lining the same as a comparative example.

The outer surface of these pipes is contacted with water at about 10 ° C, and the inner surface is
A test was performed for 2000 hours in a state where hot water of 0 ° C. was contacted. After the completion of the test, the appearance of the resin coating layer of the tube was inspected. As a result, those having a porous layer were found to be normal, but a large number of blisters were observed in the comparative example having no porous layer. Also, when the adhesive force before and after the test was measured, there was almost no change at about 10 Kg / cm before and after the test with the porous layer, but the adhesive force was almost lost in the comparative example without the porous layer. . As described above, it was confirmed that even when the tube shape is used, the provision of the porous layer can prevent the resin coating layer from peeling and swelling.

〔The invention's effect〕

As described above, the liquid storage or transportation device of the present invention is provided with an intermediate layer having a porous structure having continuous pores between the resin-coated metal material constituting the liquid storage or transportation device and the metal material of the resin-coated layer, and Since the holes are open to the atmosphere, environmental chemicals and water that have permeated the resin coating layer are not trapped between the resin coating layer and the metallic material ground surface and do not become a high pressure. It is possible to prevent swelling and peeling of the resin coating layer for a long period of time even under the condition of a large temperature gradient. Moreover, the present invention can be applied to both a normal lining structure and a loose lining having a vent hole. When applied to a normal lining structure, the coating layer, the intermediate layer,
Since the metal material is adhered, the coating layer thickness can be reduced,
Further, it is possible to obtain an advantage that it can be used for negative pressure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a resin-coated metal material constituting the liquid storage or transportation device of the present invention, and FIG. 2 is an embodiment 1
Graph showing the change with time of the adhesive strength measured in
FIG. 4 is a graph showing the change with time of the weight of the test piece measured in Example 1, and FIG. 4 is a sectional view showing the tube used in Example 5. 1 ... resin coating layer, 2 ... metal material ground layer 3 ... intermediate layer, 4 ... vent hole 6 ... steel pipe with flanges at both ends, 7 ... porous layer 8 ... resin coating layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-54-141016 (JP, A) JP-A-56-56856 (JP, A) JP-A-47-39491 (JP, A) JP-A-53- 7781 (JP, A) JP 53-8683 (JP, A) Actually developed 53-156951 (JP, U)

Claims (1)

[Claims] 1. A liquid storage or transportation device comprising a resin-coated metal material obtained by coating a metal material substrate with a corrosion-resistant resin coating layer, wherein the resin-coated metal material is the resin coating layer and the metal material substrate. In between, there is an intermediate layer having a porous structure with continuous pores and having a thickness of 0.1 to 1 mm,
Further, the liquid storage or transportation device is characterized in that the continuous pores of the intermediate layer are open to the atmosphere.