JPS60225745A - Synthetic resin composite tube for protecting tube - 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 synthetic resin composite tube for a protective tube.

Conventional technology: Currently, metal pipes and thermoplastic resin pipes are used as protection pipes for electrical wiring in houses, buildings, factories, etc., electrical wiring for computers and office automation-related equipment, and fluid transfer piping in chemical plants, etc. ing.

These protective tubes are effective for organizing wiring and piping and at the same time preventing physical forces such as external tension and impact, corrosive atmosphere, and chemical attack such as water and chemicals. Problems remain in terms of flame resistance.

Although the metal tube itself has excellent heat and flame resistance,
They have poor insulation properties, and in the event of a fire, high heat can easily be transmitted, leading to the risk of destroying internal logs and piping, or causing the fire to spread to the surrounding area. Furthermore, it is well known that thermoplastic resin pipes have poor heat resistance and flame resistance.

Therefore, it is possible to use thermosetting resin pipes that have high heat resistance, flame resistance, corrosion resistance, and heat insulation properties for this purpose, but conventional molding methods are expensive and have physical problems. Therefore, it has not been put into practical use for this purpose.

In other words, long thermosetting resin tubes are generally molded by plunger extrusion, but this molding method requires high extrusion pressure in the mold section and is intermittent extrusion. , it is difficult to obtain uniform molded products, and the buryability is low.

For this reason, a molding method using a die and a screw extruder has been developed, but this method tends to cause resin to stagnate, cause the curing reaction to proceed locally, and when the pressure or temperature is too small. This causes problems such as rapid curing reactions due to changes in the temperature, making it difficult to perform continuous and stable molding.

Moreover, in both the plunger extrusion method and the extrusion method using a die and screw extruder, conventional forming methods can only provide pipes with low strength in the circumferential direction, and as a result, Weak (for example, a slight impact easily causes cracks in the axial direction of the tube (a practical problem). This is thought to be due to the conventional extrusion method, which is oriented in the axial direction of the tube.

In other words, in conventional extrusion molding methods, molten resin is shaped and hardened while moving along the flow path in the mold, but the direction of movement of the resin during that time is in the extrusion direction, that is, the direction of the tube. This is thought to be because the resin, filler, etc. are oriented in that direction since it is only in the axial direction.

The present inventors aimed to solve these shortcomings and provide a protective tube that is heat resistant, flame resistant, corrosion resistant, lightweight, and inexpensive.
As a result of various studies, we found that an extruded thermosetting resin tube in which the resin and/or filler is irregularly oriented has a good balance of compressive strength in the tube axis direction and in the direction perpendicular to the tube axis. As a result, we discovered that the thermosetting resin tube has properties that are strong against internal and external pressure (and resistant to vertical cracking against impact).Furthermore, by coating the surface of this thermosetting resin tube with thermoplastic resin, we have achieved heat resistance and flame resistance. It was discovered that a composite tube with excellent impact resistance etc. and suitable as a protective tube could be obtained.Furthermore, by using Sufu IJ, which has a smooth part at the tip, it retained its own shape after extrusion in the smooth part. The inventors have discovered that the desired synthetic resin composite tube can be obtained by coating a thermosetting resin tube that has been shaped to the extent possible with a thermoplastic resin, and have arrived at the present invention.

Components of the Invention: That is, the present invention provides a thermosetting resin tube in which a thermoplastic resin is coated on the surface of an extruded thermosetting resin tube characterized in that the resin and/or the filler are oriented in irregular directions. The thermosetting resin tube forming the inner layer of the composite tube has a ratio of compressive strength in the direction perpendicular to the tube axis to compressive strength in the tube axis direction of 0.4 to 1.5. It is characterized by

The composite tube of the present invention is obtained by forming and hardening the thermosetting resin tube to the extent that it can maintain its own shape after extrusion at the tip using an extrusion molding machine with a built-in screen. It is obtained by coating with resin, and is manufactured, for example, by the method described in Japanese Patent Application No. 58-218645.

That is, using a screen with a smooth part at the tip,
This is a method in which thermosetting resin is shaped to the extent that it can maintain its own shape in the smooth part, and the surface is coated with thermoplastic resin. A first method in which the thermosetting resin is shaped to the extent that it can maintain its own shape in the smooth part, and the zone where the thermosetting resin is shaped is press-fitted and coated with thermoplastic resin, and then extruded. Similarly, thermosetting resin is shaped and extruded to the extent that it can maintain its own shape in the smooth part,
A second method may be adopted in which the resin is subsequently introduced into the mold of another extruder and coated with a thermoplastic resin.

The thermosetting resin tube that forms the inner layer of the composite tube of the present invention is manufactured, for example, by the method described in Japanese Patent Application No. 58-51526, and the feature of this manufacturing method is that it uses a screw having a smooth portion at the tip. The purpose is to shape and harden the smooth part to the extent that it can maintain its own shape after extrusion, and by this method it is possible to manufacture thermosetting resin pipes, which were conventionally difficult to extrude, with good productivity and at low cost. .

In other words, the pyroclastic resin material introduced into the extruder is
Screw IJ - is heated and melted while passing through the supply section and compression section, passes through the metering section, moves from the tip of the flight of the metering section to a smooth part in a helical shape, and there, due to frictional resistance with the inner wall of the cylinder, it is melted by the screw flight. The resulting gap is narrowed and finally pressure fused. The resin is then hardened and shaped while traveling through the smooth section, and is extruded from the tip of the cylinder into a continuous tube. During this time, the resin moves while being subjected to shear in the direction along the screw groove from the supply section to the metering section, so the resin itself and the filler are oriented in a particular direction with respect to the extrusion direction of the tube. After the resin is oriented in an irregular direction and transferred to a smooth part, the resin itself and the filler are oriented in a well-balanced manner in the axial direction and circumferential direction of the tube as the curing progresses. It is thought that the balance of compressive strength in the direction perpendicular to the axis is improved.

The orientation of the resin and filling of the tubes of the invention can be observed, for example, by electron microscopy.

Figure 1 is an electron micrograph of a cross section in the extrusion direction of a phenolic resin tube extruded by a conventional extrusion method (a set of plungers), and Figure 2 is the same (electron micrograph in a direction perpendicular to the extrusion direction). 6 and 4 are electron micrographs of respective cross sections of a phenolic resin pipe, which is one of the thermosetting resin pipes of the present invention.

In Figures 1 and 2 it is clear that the glass fibers are oriented in the direction of the tube axis, whereas in Figures 3 and 4 the fibers are not particularly oriented in a fixed direction. It can be seen that the particles are irregularly oriented.

Table 1 below shows the compressive strength in the direction perpendicular to the tube axis (A, the compressive strength in the tube axis direction (B), the ratio of A/B, and the results of the water pressure test. As can be seen from this table, Compared to the pipe made by the conventional method, which has a small A/B ratio of 037 and is prone to vertical cracking, the pipe of the present invention has a large A/B ratio of 04 to 15, and does not cause vertical cracking (it is easy to You can see that it is strong.

In the present invention, the compressive strength in the tube axis direction is defined by JIS-
The test (compressive strength test) according to Section 5.19.5 of -6911 is performed, and the strength when the pipe is broken (including when cracks occur) is expressed. What is the compressive strength in the direction perpendicular to the pipe axis? This indicates the strength when the pipe breaks when tested according to JIS-6741, Section 5.6 (flattening test).

In the thermosetting resin tube of the present invention, the ratio of the compressive strength in the direction perpendicular to the tube axis and the compressive strength in the tube axis direction obtained by the above method is generally 0.4 to 1.5, preferably 0.4 to 1.5. 5-1.
It is in the range of 5. If this ratio is less than 0.4, vertical cracks are likely to occur when subjected to impact or when exposed to high internal and external pressure (the cracks will extend over a long distance in the tube axis direction. Also, if this ratio is 1 If it is .5 or more, the strength becomes weaker in the direction perpendicular to the tube axis and the tube becomes more likely to break.

The thermosetting resin pipe thus obtained has excellent heat resistance and can be used with oils such as heavy oil, gasoline, and kerosene, organic solvents such as 7A/coal, ketones, esters, and aromatic hydrocarbons, acids, and alkalis. Not only is it resistant to
By using phenol resin, melamine resin, xylene resin, etc. as the molding material, it has excellent properties such as not spreading when exposed to flame, not causing dropping, maintaining its original shape, and not emitting toxic gas. It has flame resistance properties, and because the resin and/or filler is oriented in the extrusion direction of the tube and in the circumferential direction, the strength is well balanced in the extrusion direction of the tube and in the direction perpendicular to it. It has excellent pressure resistance.

Thermosetting resins used in the present invention include phenolic resins, melamine resins, urea resins, unsaturated polyester resins, epoxy resins, silicone resins, allyl resins, xylene resins, aniline resins, etc. Among them, Preference is given to using phenolic resins, melamine resins and urea resins.

The thermosetting resin used in the present invention may contain fillers, mold release agents, thickeners, colorants, dispersants, blowing agents, or polymerization initiators commonly used in the molding of thermosetting resins, as necessary. A curing agent, a curing accelerator, a polymerization inhibitor, and the like can be added.

In the present invention, organic or inorganic fibrous substances such as wood flour, cotton, nylon fiber, vinylon fiber, glass fiber, carbon fiber, metal fiber, etc. For example, it can be added in a high quantitative range, such as 20 to 80% by weight as a total amount with the above-mentioned fillers.

Examples of the thermoplastic resin used in the present invention include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, polymethyl acrylate, and polyethylene terephthalate. Additives commonly used in the molding of thermoplastic resins, such as stabilizers, fillers, processing aids, antioxidants, reinforcing agents, colorants, and lubricants, may be added to these thermoplastic resins as necessary. Can be added.

The thermosetting resin pipe molded by the above-described method is coated with a thermoplastic resin by the above-described first method or second method to obtain a composite pipe.

The composite tube thus obtained has an inner layer made of a thermosetting resin with excellent heat resistance, flame resistance, and corrosion resistance, and an outer layer made of a thermoplastic resin with excellent impact resistance. It has excellent durability and impact resistance, making it suitable as a protective tube.

Industrial Application Fields: Specifically, the composite pipe of the present invention can be used as a protection pipe for general electrical wiring indoors or outdoors in houses, buildings, factories, etc., electrical wiring for computers and office automation related/equipment, It can be used for optical fiber protection tubes, etc.

By using the protective tube of the present invention in these applications, it not only protects electric wires, optical fibers, etc. from high temperatures, water, moisture, shock, etc., but also protects electric wires, optical fibers, etc. from high temperatures, water, moisture, shock, etc., and even in the event of a fire, its flame resistance will prevent the fire from occurring. In addition, since the thermal conductivity is much lower than that of metal pipes, it takes a considerable amount of time for the inside of the pipe to reach high temperatures and burn out the electric wires, so appropriate measures can be taken during that time.

Furthermore, since the protection tube of the present invention has excellent corrosion resistance and chemical resistance, it can also be used as a protection tube for pipes for transferring gases and liquid substances in chemical plants and general factories.

The present invention will be further explained below using reference examples and production examples.

Reference Example 1 Compression using an extruder with a diameter of 60mm and L/D=22, which has a smooth part with a diameter of 26 blades and a length of 105mJR (3,5D) at the tip of the screw following the measuring part with a diameter of 26m5 at the bottom of the screw. Specific force 2.0 Nosk! A pipe was continuously extruded using a phenol resin (manufactured by Nippon Oil Seal ■, trade name: Rogers RX-6684) as a molding material.

The temperature of each part of the cylinder is C + (0 to 2D) - water cooling, C
2(3D~10D) = 80'C1Ca(11D~
18D)=1[10℃, C4(19D~22D)=1
Extrusion molding was carried out under the conditions of 20'GK setting and screw rotation speed of 35 rpm to obtain a pipe with an outer diameter of 30 mm and a wall thickness of 2.0 mm.

Reference Example 2 Using the same extrusion device as Reference Example 1, phenol resin (manufactured by Nippon Gosei Kako ■, trade name Futtsukarai) 95 was used as a molding material.
0-J) was used to extrude the pipe.

The temperature of each part of the cylinder is ci-water cooling, C2=80℃,
Molding was carried out under the conditions of Cs = 110°C, C4 = 120'CK, and screw rotation speed of 33-5 rpm to obtain a pipe with an outer diameter of 3° and a wall thickness of 20°.

Reference Example 3 Using the same extrusion device as Reference Example 1, molding material and shitephenol resin (manufactured by Sumitomo Bakelite ■, product name PM-79) were used.
5J) was used to extrude the pipe.

The temperature of each part of the cylinder is Cl - water cooling, C2 = 8[1'C
1C5 = 105°C, C4 = 120°C, molding was performed under the conditions of screw rotation speed 35 rpm, outer diameter 3
A pipe with a diameter of 0 m5 and a wall thickness of 20 m was obtained.

Reference Example 4 Using an extruder with a diameter of 40 and L/D = 24, a screw IJ with a diameter of 65 mm at the bottom of the screw and a measuring section with a length of 3D followed by a smooth section with a diameter of 35 m and a length of 3D was produced. A pipe was extrusion-molded using a phenol resin (manufactured by Sumitomo Bakelite ■, trade name PM-795J) as a molding material. The temperature of each part of the cylinder is C+ (Q ~ 2D) - water cooling, C2
(3~10D)-60°C, C3(11~16D)=8
0℃, C4(17~20D)-110℃, (j(21~
24D) Set at -120℃, Scree rotation speed 25rp
I obtained a pipe with an outer diameter of 40 mm and a wall thickness of 25 mm.

Reference Example 5 Using the same extrusion apparatus as in Reference Example 1, a pipe was continuously extruded using melamine resin (manufactured by Otalite ■, trade name 0N-600) as a molding material.

The temperature of each part of the cylinder is C+ = water cooling, C2 = 85℃, C
Setting n = 115°C, C4 = 130°C, molding was carried out under the conditions of screw rotation speed 35 rpm, outer diameter 60
Well, I got a pipe with a wall thickness of 20mm.

Evaluation results: The results of the compressive strength (direction perpendicular to the tube axis, the direction of the tube axis, and the ratio thereof) and the hydraulic pressure test of the pipe obtained in the above production example were as shown in the first element.

Reference Example 6 Using the same extrusion equipment as in Reference Example 1, epoxy resin (manufactured by Nippon Gosei Kako ■, trade name Acmelite J-) was used as the molding material.
1060F) was used to extrude the pipe.

The temperature of each part of the cylinder is C+-water cooling, C2 = 85°C1
Molding was carried out at C5 = 115℃, C4 - 125℃, screw rotation speed 35rpm, outer diameter 30U.
A pipe with a wall thickness of 2.0 mm was obtained.

Production Example 1 A water cooling jacket is provided at a length of 2D from the bottom of the hopper, followed by a thermal control device at each part of 3 to 9D, 10 to 15D, and 16 to 19D, and then a thermoplastic jacket is provided at a position of 2D from the tip. An extruder (5) having a cylinder with a diameter of 40 mm and L/D-24 (including the coating device part) equipped with a coating device (length 5D) that allows the resin to be supplied with a wall thickness of 15 ° C.
, a feeding section 3D, a compression section 12D, a metering section with a diameter of 35 mm and a length of 4 D at the bottom of the screw, followed by a smooth section with a diameter of 65 mm and a length of 5 D, and a screw with a compression ratio of 1.8, and a compression ratio of 25 mm. A composite tube was formed using an extruder (C1) with a diameter of 60 mm and L/D = 22 equipped with a screw.

An extruder (C1) is connected to the coating device section of an extruder (3) equipped with a Sufu IJ, -[F]), and the extruder (C1) is used as a molding material.
b) Phenol resin (manufactured by Sumitomo Bakelite ■, trade name PM-795J), extruder (q) polyvinyl chloride compound (manufactured by Mitsui Toatsu Chemical ■, trade name Vinicron EREK)
-1015), and the extruder (5)
) - water cooling, C2 (3~9D) -80° CSC, + (10
~15D) -95°C, C4 (16-19D) -110°C
, coating device part (20-24D) -180°C, screw rotation speed 2.5 rpm, extruder (C1 is C1 (0-2
D)=Water cooling, C2(3~9D)-150°C1C5(1
0~16D)=170℃, C4(17~22D)=1
75℃, adapter -180℃, screw rotation speed 4
Extrusion was carried out under the conditions of 5 rpm, and the inner layer was a phenolic resin with a diameter of 40 m5 and a wall thickness of 2.5 ma+, and the outer layer was a diameter of 41.5 m.
a Outer diameter 4 made of polyvinyl chloride resin with a wall thickness of 1.5 ms
A composite tube with a length of 5 ms and a wall thickness of 4 mm was obtained.

Production Example 2 A water cooling jacket was provided at a length of 2D from the bottom of the hopper, followed by 3~10D, 11~16D, 17~20D and 21
~24D diameter 40+1IJ with heat control device in each part
By using an extruder with IL/D=24 cylinders, the diameter of the supply section 3D, compression section 15D and screw bottom is 5.
A melamine-phenol resin (manufactured by Matsushita Electric Works, trade name: ME-A) was used as a molding material.
) was used to extrude the pipe.

The temperature of each part of the cylinder is C1 (0-2D) = water cooling, C2
(6~IDD)=60℃, Cs (11~16D)=8
5℃, C4 (17~20D) -120℃, C5 (21~
24D) Set at -130℃, Scree rotation speed 25rp
A pipe with an outer diameter of 40 m and a wall thickness of 2.5 m was extruded. This pipe was directly introduced into a crosshead die attached to an extruder with a diameter of 30m5L/n = 22 equipped with a screw with a compression ratio of 60, and the temperature was set as follows.
C1-180℃, C2=210℃, C+=220℃,
Under the conditions of -220℃ and screw rotation speed of 62 rpm, polypropylene resin (manufactured by Mitsui Toatsu Chemical ■, product name: Mikata Noblen BEB-US) is coated with a wall thickness of 15 mm, and the inner layer has an outer diameter of 40 mm and a wall thickness of 2 mm. A composite tube with an outer diameter of 415 m and a wall thickness of 4 m x was obtained, the outer layer being made of a polypropylene resin with an outer diameter of 415 m and a wall thickness of 15 mm.

Comparative Example 1 Using the 40 mm extruder and screw used in Example 2, extrusion molding was performed using a phenol resin (manufactured by Sumitomo Bakelite ■, trade name PM-795J) as a molding material. The temperature of each part of the cylinder is C1 = water cooling, C2-60
℃, Ca=80℃, C4=110'C1C5-120
℃, and molding was carried out at a scree rotation speed of 25 rpm to obtain phenol pipes with an outer diameter of 40 pieces and a wall thickness of 2.5M.

Table 2 shows the performance measurement results of the tubes obtained in each Example and Comparative Example.

These results show that the synthetic resin composite tube of the present invention has excellent heat resistance, flame resistance, and impact resistance, and is suitable as a protection tube.

[Note] 1. Manufactured by T Kogyo ■, product name: E (abbreviation) [Note] 2. The test method is according to JISK6742, the water pressure is increased and the pressure at which the pipe breaks is read.

[Note] 6. A tube with a length of 5 m was immersed in the test liquid, and after being left under the following conditions, changes were observed.

Hot water -100℃ x 24 hours Other test solutions - room temperature x 1 week

[Brief explanation of drawings]

Figures 1 and 2 are electron micrographs of the shape of the filled fibers in the cross section of a phenolic resin tube extruded by a conventional extrusion method, in the tube axis direction and in the direction perpendicular to the tube axis, respectively. , 6 and 4 are electron micrographs of phenolic resin tubes forming the inner layer of the synthetic resin composite tube of the present invention. Patent Applicant Mitsui Toatsu Chemical Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Procedural Amendment August 24, 1980 Manabu Shiga, Commissioner of the Patent Office 1, Indication of Case Patent Application No. 81, 1982 .078 No. 2, Name of the invention Synthetic resin composite tube for protection tube 3, Person making the amendment 4, Daily publication of the amendment order July 31, 1982 (shipment date) 5. Brief explanation of the drawings of the specification subject to the amendment Column (1) Specification old handwriting 2: Page 3, line 7, 1 - Replaced "each" with "
-1 is corrected for the filled fibrous shape of each cross section in the tube axis direction and in the direction 1 perpendicular to the tube axis. Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Claims] 1) A synthetic resin composite tube for a protective tube, which is made by coating the surface of an extruded thermosetting resin tube with a resin and/or filler oriented in irregular directions with a thermoplastic resin. . 2) The ratio of the compressive strength in the direction perpendicular to the tube axis and the compressive strength in the tube axis direction of the thermosetting resin tube forming the inner layer is 0.4 to 15.
A synthetic resin composite tube for a protection tube according to claim 1. 3) A screw having a smooth portion at its tip is used, a thermosetting resin is shaped in the smooth portion to the extent that it can maintain its own shape, and the surface of the screw is coated with a thermoplastic resin. A synthetic resin composite tube for a protective tube according to items 1 and 2.