JPH0976279A - Manufacture of pipe-end anticorrosion type joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a pipe end anticorrosion joint by a method wherein the pipe end anticorrosion joint wherein a resin-made pipe-end anticorrosion member covering a connection side end surface of a pipe connected to a metallic pipe joint and its inner peripheral surface is integrally provided on the inner peripheral part of the pipe joint can be manufactured in excellent quality by a shortened manufacturing process in comparison with a conventional method. SOLUTION: In a manufacturing method for a pipe-end anticorrosion proof joint wherein a resin-made pipe end anticorrosion member 3 covering a connection side end surface of a pipe connected to a metallic pipe joint 1 and its inner peripheral part of the pipe joint 1, after applying epoxy polymer onto a metallic inner surface of the heat-treated pipe joint 1, adhesive polymer is applied and cooled while the epoxy polymer is under a heated state. Further, the anticorrosion member is molded by injection on the adhesive polymer layer 9 to be integrated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a pipe end anticorrosion type pipe joint for corroding an end face portion of a pipe connected to the pipe joint.

[0002]

2. Description of the Related Art Generally, as a method for producing a pipe end anticorrosion type pipe joint, for example, in Japanese Patent Publication No. 6-89864,
A primer treatment means for heat-treating an epoxy-based polymer on an oxide layer formed on a metal inner peripheral surface of a pipe joint, a functional group polymer treatment means for applying an adhesive polyolefin to the primer-treated surface and cooling it again after heat treatment, and a polymer. Disclosed is a method for integrally coupling a pipe joint and a pipe end anticorrosion member by means of a rapid melting treatment means for rapidly melting only the treatment surface and a resin molding treatment means for forming a pipe end anticorrosion member on the melting treatment surface. .

However, in the above-mentioned method, in the actual manufacturing process, the inner metal surface of the joint is cleaned, the primer on the inner metal surface of the joint is heated, the polymer is applied to the primer-treated surface and cooled after re-heat treatment, polymer treatment Since there are five steps of melting the surface and injection-molding the resin on the melt-processed surface, there is a problem that the number of manufacturing steps is large and the time required for manufacturing is long.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to make a resin pipe end anticorrosion covering a connection side end face and an inner peripheral face of a pipe connected to a metallic pipe joint. A member is a pipe end anti-corrosion joint that is integrally provided on the inner peripheral portion of the pipe joint. To provide.

[0005]

The method for producing a pipe end anticorrosion type pipe joint according to the invention of claim 1 (hereinafter referred to as the first invention) comprises:
In a method for producing a pipe end anticorrosion joint integrally provided on the inner peripheral portion of the pipe joint, the resin pipe end anticorrosion member covering the connection side end face and the inner peripheral face of the pipe connected to the metallic pipe joint. After the epoxy-based polymer is applied to the metal inner surface of the heat-treated pipe joint, the adhesive polymer is applied and cooled while the epoxy-based polymer is in a heated state, and the corrosion-resistant member is further provided on the adhesive polymer layer. Is characterized by being injection-molded and integrated.

According to a second aspect of the present invention (hereinafter referred to as the second aspect of the invention), a method of manufacturing a pipe end anticorrosion type pipe joint is made of resin which covers the connection side end face and the inner peripheral face of the pipe connected to the metallic pipe joint. The pipe end anticorrosion member is a method for producing a pipe end anticorrosion joint integrally provided on the inner peripheral portion of the pipe joint, in which a mixture of an epoxy polymer and an adhesive polymer is applied to the metal inner surface of the heat treated pipe joint. After cooling, the anticorrosion member is injection-molded and integrated on the mixture layer.

Examples of the adhesive polymer include adhesive polyolefin (“Admer” manufactured by Mitsui Petrochemical Co., Ltd.), polyester hot melt adhesive (“Aron melt PES” manufactured by Toagosei Co., Ltd.) and the like.

(Operation) In the manufacturing method of the first invention, as the primer treatment, the epoxy-based polymer is applied to the metal inner surface of the heat-treated pipe joint, and the adhesive polymer is applied while in the heated state, Since only one heat treatment is required, the manufacturing process can be shortened. Further, by increasing the temperature of the resin to be injection-molded, the melting process of the adhesive polymer becomes unnecessary, so that the manufacturing process can be shortened. In the manufacturing method of the second invention, the manufacturing process can be shortened by applying the mixture of the epoxy-based polymer and the adhesive polymer to the inner surface of the metal of the heat-treated pipe joint and cooling the mixture. Further, by increasing the temperature of the resin to be injection-molded, the melting process of the adhesive polymer becomes unnecessary, so that the manufacturing process can be shortened.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a cross-sectional view showing a pipe end anticorrosion type pipe joint obtained by the manufacturing method of the present invention, 1 is a cast iron pipe joint, and the pipe joint 1 is an inner peripheral surface of both ends. Has a female thread 2 for pipe joining. In the manufacturing method of the present invention, first, the joint is washed with a degreasing solution of trichloroethylene to remove the cutting oil on the metal surface and form an oxide layer. Next, in order to improve the adhesiveness of the metal surface, a powdered epoxy polymer is applied to the inner surface of the pipe joint 1 heated to 180 to 200 ° C. and the surface of the spinning member 3 to be bonded. This powdery epoxy polymer is used as a primer for the adhesive polymer described later. Further, while the epoxy polymer is in a heated state, an adhesive polymer (“Admer” manufactured by Mitsui Petrochemical Co., Ltd.) is applied and cooled to obtain an adhesive polymer layer 9
To form The adhesive polymer layer 9 is preferably formed so as not to cover the female screw portion 2 on the inner peripheral surface of the pipe joint 1.

Next, a cross-linked polyethylene having a resin temperature of 220 ° C. or higher is injection-molded on the inner surface of the pipe joint 1 to form the spinning member 3. The spinning member 3 is formed so that the large-diameter outer diameter portion 3b comes into contact with and adheres to the adhesive polymer layer 9 provided on the inner peripheral surface of the joint 1, and further, the end outer-diameter portion 3a thereof is formed. An insertion gap 4 is provided between the female screw 2 and the female screw 2.
The outer diameter portion 3a of the end portion is formed to have a smaller diameter than the outer diameter portion 3b of the large diameter. Further, the large diameter outer diameter portion 3b and the end outer diameter portion 3a
An escape groove 6 is provided at the corner where the and contact.

The above-mentioned insertion gap 4 is provided when the lining steel pipe 5 which will be described later is connected to the inner surface of the pipe joint 1.
It is sufficient if there is a gap required for the insertion. In the above-mentioned injection molding, the cross-linked polyethylene in a molten state is injected to form the spinning member 3 on the inner surface of the pipe joint 1, and the spinning member 3
Melts the adhesive polymer layer 9 and strongly adheres them to each other to integrate them, whereby the pipe end anticorrosion type pipe joint of the present invention can be obtained.

When connecting a lining steel pipe using the above pipe end anticorrosion type pipe joint, as shown in FIG. 2, after the male screw 7 is provided on the outer surface of the tip of the lining steel pipe 5 having the lining layer 10 on the inner surface, The male thread 7 of the lining steel pipe 5 and the female thread 2 of the pipe joint 1 are fitted together. By this fitting, the lining steel pipe 5 is inserted into the insertion gap 4 and a sealed state is formed. At this time, in order to further enhance the sealing effect of the lining steel pipe 5 and the pipe joint 1, a seal material 8 is interposed between the male screw 7 and the female screw 2. However, when the seal material 8 is excessive, the excess seal material 8 is used. Can be stored in the escape groove 6. Further, it is preferable that the lining steel pipe 5 be fitted until the end face of the lining steel pipe 5 contacts the large-diameter outer diameter portion 3b of the core 3.

Example 2 As an adhesive polymer, instead of "Admer" manufactured by Mitsui Petrochemical Co., Ltd., a polyester hot melt adhesive ("Aron Melt P" manufactured by Toagosei Kagaku Co., Ltd.) was used.
ES ") was used, and a chlorinated vinyl chloride resin was used in place of the crosslinked polyethylene, to obtain a pipe end anticorrosion type pipe joint in the same manner as in Example 1.

(Example 3) Except that a primer of an adhesive polymer was not used at all and a mixture of a powder epoxy polymer and an admer in a ratio of 1: 1 (weight ratio) was used as the adhesive polymer. In the same manner as in Example 1, a pipe end anticorrosion type pipe joint was obtained. The mixing ratio of the powdered epoxy polymer and the Admer is preferably 1: 2 to 2: 1 (weight ratio). It is preferable that the powdered epoxy polymer and the Admer have similar particle diameters and bulk specific gravities, so that separation of the two is avoided and a uniform adhesive polymer layer is formed.

(Example 4) Except that a primer of an adhesive polymer was not used at all and a mixture of a powder epoxy polymer and Aronmelt PES at a ratio of 1: 1 (weight ratio) was used as the adhesive polymer. A pipe end anticorrosion type pipe joint was obtained in the same manner as in Example 2.

[0016]

The method for producing a pipe end anticorrosion type pipe joint according to the first aspect of the present invention has the above-mentioned constitution, and since the adhesive polymer is applied while the epoxy polymer is in a heated state, the adhesive polymer is applied. Heat treatment for injection molding is unnecessary, and by increasing the resin temperature during injection molding, the heating and melting step of the adhesive polymer is not necessary, so the time required can be shortened compared to conventional manufacturing methods. it can.

The method of manufacturing the pipe end anticorrosion type pipe joint of the second invention has the above-mentioned constitution, and since the mixture of the epoxy polymer and the adhesive polymer is applied, the step of applying the epoxy polymer (primer) is unnecessary. And then
By increasing the resin temperature at the time of injection molding, the heating and melting step of the adhesive polymer becomes unnecessary, so that the required time can be shortened as compared with the conventional manufacturing method.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a pipe end anticorrosion type pipe joint obtained by an embodiment of a manufacturing method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a lining steel pipe is connected to the pipe end anticorrosion type pipe joint of FIG.

[Explanation of symbols]

 1 Pipe Joint 2 Female Thread 3 Anticorrosion Member 3a End Outer Diameter 3b Large Diameter Outer Diameter 4 Insertion Gap 5 Lining Steel Pipe 6 Relief Groove 7 Male Thread 8 Sealing Material 9 Adhesive Polymer Layer 10 Lining Material

Claims (2)

[Claims] 1. A pipe end anticorrosion joint integrally provided on the inner peripheral portion of the pipe joint, with a resin pipe end anticorrosion member covering the connection side end face and the inner peripheral face of a pipe connected to a metallic pipe joint. In the method for producing the above, after the epoxy-based polymer is applied to the metal inner surface of the heat-treated pipe joint, the adhesive polymer is applied and cooled while the epoxy-based polymer is in a heated state, and the adhesive polymer is further added. A method for manufacturing a pipe end anticorrosion joint, characterized by comprising integrally forming an anticorrosion member on a layer by injection molding. 2. A pipe end anticorrosion joint integrally provided on the inner peripheral portion of the pipe joint, with a resin pipe end anticorrosion member covering the connection side end face and the inner peripheral face of the pipe connected to the metallic pipe joint. In the method for producing, a mixture of an epoxy-based polymer and an adhesive polymer is applied to the inner surface of the metal of the heat-treated pipe joint, the mixture is cooled, and then an anticorrosion member is injection-molded and integrated on the mixture layer. Method for manufacturing pipe end anticorrosion joint.