JPS5962794A - Metallic pipe, outer surface thereof is coated with resin - 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 gold tube whose outer surface is coated with an anticorrosion coating made of a thermoplastic resin.

In particular, the present invention aims to obtain a metal tube having a corrosion-resistant coating with a thin film thickness and high mechanical strength.

BACKGROUND ART Metal pipes having an outer surface coated with gold, such as steel pipes and cast iron pipes, are coated with a thermoplastic resin (hereinafter referred to as resin alone) that does not contain a reinforcing agent as an anti-corrosion layer. To manufacture this snout tube, thermoplastic resins such as polyethylene, polypropylene, and vinyl chloride are melt-kneaded using an extruder at a high temperature (170 to 250°C), and then formed into a sheet using a round die or a T-shaped die. The product is formed into a shape and then covered with an adhesive over a metal tube.

In the case of large-diameter pipes, external resin-coated metal pipes made using a single resin manufactured by the above manufacturing method are susceptible to damage to the coating during handling after shipment from the factory, during shipping, land transportation, or on-site piping construction. In addition, when a concentrated load is applied during shipping or stacking during stocking, the resin coating is susceptible to damage such as denting. Therefore, as a countermeasure to these problems, the coating must be made thicker (3 mm or more), which is economically disadvantageous.

In addition, in the case of small and medium diameter pipes, their own weight is relatively light and handling is easy, but during piping construction, they are usually subjected to machining such as cutting, threading, or bending, to prevent slipping. It is necessary to tighten the anti-corrosion coating by tapping it with a sharp metal nail. As a result, the nails dig into the resin coating and damage it, so it is necessary to either increase the thickness of the coating or repair the damaged part of the coating.Therefore, instead of using only Thermo-iTJ plastic resin, thermoplastic resin pellets and fibers are mixed in a dispersed manner in advance. material,
Alternatively, there is a method in which fibers are added and dispersed in advance, and hemachi plastic 4Ni:I resin pellets are formed and coated in a sheet form by extrusion. Even if the fibers of the strands are mixed, they will be shortened in the extruder (approximately 0.5
+n, +n) j, There are disadvantages such as insufficient strength improvement effect and significant abrasion due to fibers inside the extruder or die mold.

The present inventors have completed the present invention as a result of repeated research in order to solve the above-mentioned drawbacks.

According to the present invention, an anticorrosive coating made of a thermal q 913 resin reinforced with a fiber mat such as a carbon fiber mat or a plastic fiber mat is applied to the outside of a metal tube. As a means of reinforcing the anticorrosion coating, for example, when two or more layers of thermoplastic resin sheets such as melt-extruded polyethylene are laminated and fused and coated, a fiber mat such as a carphone fiber mat or a glass fiber mat is added between the layers. Insert and fuse.

As the above-mentioned fiber mat, a commercially available one can be used, and normally a material having a fiber diameter of 10 to 30 μm and a mat thickness of about 02 to 0.64 mm is used on average, but the mat is not limited thereto. Thermal i3'T plastic resins include polyethylene, polypropylene, (y12
Ti crystallized vinyl resin, nylon, etc.

Metal pipes include steel pipes, cast iron pipes, steel pipes, aluminum pipes, etc., and may have any shape such as round pipes, square pipes, tapered pipes, etc.

The outer surface resin-coated metal tube according to the present invention is particularly superior in impact resistance, scratch resistance, and compression deformation resistance compared to conventionally known corrosion-resistant metal tubes, and the effort required for coating repair is reduced. Since the film thickness can be reduced, it is possible to improve production 1' and reduce costs.

Next, the present invention will be explained in more detail with reference to Examples 1 to 10 and Comparative Examples 1 to 6. The test results of Examples and 5 specific IFs are shown in the table below.

(Example 1) A straight bead manufactured by a υ0 mill was used.
IIQ 2.5 mm thick moon 51J whose outer surface is reinforced by filling two layers of glass fiber mounts.
A polyethylene coating was formed using an adhesive using a T-type die.

This anti-corrosion wave 119λ is as shown in the table.
Drunken clothes i7 attack 1 student, compression deformation resistance is 0
Shinobu Izta.

(Example 19+12) The same procedure as in Example 1 was carried out, using a power lath fine mat of 1111.

(Example 3) Three layers of glass fiber mat are used, and the thickness of each layer is 3 and 2.
mm. Is the rest the same as in Example 1? That's it.

(Comparative Example 1) Instead of fiber mat, Cho'sobdo strand (
20 μ in diameter, zomm in length) force “Lasphi/<-(
Bow with 30 tons of polyethylene! (A 111-layer film was formed with a thickness of 2.B mm.
Well, it's the same as Example 1.

(Comparative Example 2) (Membrane rupture of 11.1lF1 body, film thickness 3.5 m71
i-kopusugiri length. Other details are the same as in Example 1.

(Example 4) Instead of glass fiber mat (2 layers Q) force-pomfer mat was used as a reinforcing agent.
%7J instead of polyethylene t as white plastic resin?
II Brohi v 7 (', 'j'! ri 1 nit), 9
30) woffl I/) f, knee. If! ”: I
"1-2,7111FI 71 was completed.Others were the same as in Example 1.

(Implementation 1 evening/1] 5) Use horn bone fiber mat at 11vS'i, t, N
,+[? Formed at -26rnrn. Others are Example 4
Su1ji.

(Comparative Example 3) Single resin coating 11th round) Rim: 3.5 mm. Same as Example 4.

(Real 71i+; (RI1;6) Nominal diameter 80Ao) Forge welded steel pipe (Outer diameter 3g, l Irm
, thickness J2+r+m), two layers of carbon fufu'
I11^ Thickness 1.8 reinforced by filling the ear
rnm o,)n]? 1 propylene (density C1,9
05) A resin coating was formed using a master die via an adhesive. As shown in the table, this anti-corrosion coating was confirmed to have excellent impact resistance and chucking resistance.

Example No. 1 - One layer of Bonfiber mat with a film thickness of 1. '
5 Tnm. Other details are the same as in Example 6.

(Example 8) Three layers of carbon fiber mat with lI*thickness of 2
．． Formed at Qrnm. Other details are the same as in Example 6.

(Comparative Example 4) The 111th group of the resin Qi body was 1. It was formed to a film thickness of 2.0 mm. Other details are the same as in Example 6.

(Example 9) Instead of carbon fiber mat, two layers of glass fiber mat were used as reinforcing agent, and thermoplastic one-layer (h↑l
For the taste, polypropylene (density 0.910) was used. 19 Iomi 11 Real left pile 'j'IG v ljun(゛.

(Example 10) A single layer of glass fiber mat was used, and the film thickness was 5 m.
J was formed. Others are the same as in Example 9.

(Comparative Example 5) A polypropylene F resin-encrusted membrane using aged chopped strands (7i diameter 20μ, length 2 (l mm) carbon 77' iber (30% by weight based on polypropylene)) was used as a reinforcing agent. It was formed to have a thickness of 1.5 mrn.Other aspects were the same as in Example 9.

(Hirika 9j16) The film thickness of the resin alone is 2. It was formed to 0mm. Others (total, same as Example 9).

It is clear from each actual example that the fiber mat filled with layered wood has excellent corrosion resistance, impact resistance, ITE shrinkage deformation resistance of 1 V, and chucking resistance. The anticorrosion coating 11'λ of the current resin r, B body can be obtained by making the material considerably thinner.

Compared to the example 1, 5 and 5, in which the strand fibers are mixed and dispersed in the extruder, the fibers are reinforced with J% fiber matte fibers. Therefore, it can be seen that it has excellent characteristics. ] Compared to the case where only one layer of Iharmat filling layer is inserted, when increasing the number of Pine l-14 layers by two or three layers, the impact resistance is greatly improved (Q<r). .

Agent: Patent Attorney: Satoshi Sasaki

Claims (2)

[Claims] (1) An outer resin-coated metal tube characterized by having an anticorrosive coating made of thermoplastic resin reinforced with fiber mat on the outer surface of the tube. (2) a thermoplastic resin sheet with two or more layers of anticorrosion coating;
bamboo comprising a fiber mat inserted between the sheets;
1. ``The outer surface resin-coated metal tube according to claim 1.