JPS60227087A - Synthetic resin composite pipe for transporting fluid - 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 fluid transfer.

Ju J Hagi Town: Conventionally, metal pipes and thermoplastic resin pipes such as polyvinyl chloride have been used as fluid transfer pipes for transferring water, oil, and other liquid substances, and gases such as air and gas. .

Although metal pipes are strong, they are heavy, have poor workability, and have problems such as corrosion.Although they have excellent heat resistance and flame resistance, they have poor insulation properties, and in the case of a flame, they can damage the fluid inside the pipe and the pipe. High heat may be transferred to the support or the surrounding area, causing the spread of flame.

Furthermore, it is well known that thermoplastic resin pipes are lightweight, corrosion resistant, and inexpensive, but have poor heat resistance and fire resistance.

Therefore, it would be possible to provide thermosetting resin pipes with high heat resistance, fire resistance, corrosion resistance, heat insulation properties, etc. for this purpose, but conventional molding methods would be expensive and have physical problems. Because of this, it has not been put into practical use for this purpose.

In other words, long tubes of thermosetting resin are generally formed by plunger extrusion, but this molding method requires high extrusion pressure in the mold, and moreover, it is not possible to use intermittent extrusion. Therefore, it is difficult to obtain uniform molded products,
Monthly productivity is also low.

For these reasons, 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, or cause molding to occur under slight pressure or temperature. 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 extrusion method using a plunger set 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, the internal and external pressure For example, a slight impact can easily cause cracks in the axial direction of the tube, which is a practical problem. This is thought to be because in conventional extrusion methods, the resin itself and the filler are oriented in the extrusion direction, that is, in the axial direction of the tube.

Purpose of the invention: As described above, in the conventional method, shaping and curing proceed while the molten resin is introduced into the mold and moves along the flow path within the mold. This is thought to be because the direction of movement is only in the extrusion direction, that is, in the tube axis direction, so the resin, filler, etc. are oriented in that direction.

The inventors of the present invention have conducted various studies to solve these drawbacks and provide a lightweight and inexpensive fluid transfer pipe that has heat resistance, flame resistance, and corrosion resistance. The irregularly oriented extruded thermosetting resin tube has a good balance of compressive strength in the tube axis direction and in the direction perpendicular to the tube axis, making it strong against internal and external pressure and shock resistant. We discovered that this thermosetting resin tube has properties that make it difficult to crack vertically, and by coating the surface of this thermosetting resin tube with a thermoplastic resin, we have created a composite tube that has excellent heat resistance, flame resistance, impact resistance, etc., and is suitable for use as a fluid transfer tube. It was found that a tube can be obtained. Furthermore, by using a screw with a smooth part at the tip and coating a thermoplastic resin on a thermosetting resin tube that has been shaped to the extent that the smooth part can maintain its own shape after extrusion,
The present invention was achieved by discovering that these synthetic resin composite pipes can be obtained.

Structure of the invention: That is, the present invention is a tube made of a thermosetting resin tube, which is characterized in that the resin and/or filler is oriented in irregular directions, and is formed by coating the surface of a thermosetting resin tube with a thermoplastic resin. This is a synthetic resin composite tube for fluid transfer, and 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. characterized by something.

The composite tube of the present invention uses an extrusion molding machine with a built-in screw, and the surface of the thermosetting resin tube is made of thermoplastic material by shaping and curing the tip of the extrusion molding machine to the extent that it can maintain its own shape after extrusion. It is obtained by coating with a resin, and is manufactured, for example, by the method described in Japanese Patent Application No. 58-218645.

In other words, this method uses a screw with a smooth part at the tip, shapes the thermosetting resin in the smooth part to the extent that it can maintain its own shape, and then coats the surface with the thermoplastic resin. Specifically, a screw having a smooth portion at the tip is used to shape the thermosetting resin to the extent that it can maintain its own shape in the smooth portion, and then the thermosetting resin is placed in the zone to be shaped. The first method involves press-fitting a thermoplastic resin and extruding it, or similarly, shaping the thermosetting resin to the extent that it can maintain its own shape in a smooth part and then extruding it, followed by another method of extruding the thermosetting resin by press-fitting it and extruding it. A second method can be adopted in which the resin is introduced into a mold 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 thermoplastic resin material fed into the extruder is
It is heated and melted as it passes through the screw supply section and the compression section, passes through the metering section, and moves from the tip of the flight of the metering section to a smooth section in a helical shape, where the gap created by the screw fly IIc due to frictional resistance with the cylinder inner wall. 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 generally 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 irregular directions and transferred to a smooth portion, the resin itself and the filler are oriented in a well-balanced manner in the axial and circumferential directions of the tube as the curing progresses. It is thought that the balance of compressive strength in the direction perpendicular to the tube axis becomes better.

The orientation of the resin and filler in the tube of the present invention can be observed using, for example, an electron microscope.

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 (with a plunger set), and Figure 2 is an electron micrograph of the cross section taken in the direction perpendicular to the extrusion direction. , 3 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 Figs. 1 and 2, it is clear that the glass fibers are oriented in the tube axis direction, whereas in Figs.
The figure shows that the fibers are not oriented in a particular direction, but are oriented irregularly.

Table 1 below shows the compressive strength (A) in the direction perpendicular to the tube axis.
The compressive strength (B) in the axial direction of the pipe, the ratio of A/B, and the results of the water pressure test are shown.As can be seen from this table, the pipe made by the conventional method has a small Al1 ratio of 0.37, and does not suffer from longitudinal cracking. Compared to this, the tube of the present invention has a ratio of o, 4 to 1.
．． 5, which shows that it is strong against internal pressure without causing large vertical cracks.

In the present invention, the compressive strength in the tube axis direction is defined by JIS
A test (compressive strength test) according to Section 5.19.5 of -K-6911 is performed, and the strength when the pipe is broken (including cracks) is expressed as the compressive strength in the direction perpendicular to the pipe axis. represents the strength when the tube breaks when tested in accordance with Section 5.6 of JIS-6741 (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 by the above method is generally 064 to 1.5, preferably 0.5 to 1.
It is in the range of 5. If this ratio is 0.4 or more, vertical cracking is likely to occur when subjected to impact or when exposed to high internal and external pressure, and the cracks will extend over a long distance in the tube axis direction. If this ratio is 1.5 or more, the strength becomes weaker in the direction perpendicular to the tube axis, making the tube more likely to break.

The thermosetting resin pipe thus obtained has excellent heat resistance and can withstand heavy oil, gasoline, kerosene, and other oils, alcohol, keto/, esters, aromatic hydrocarbons, and other organic solvents.
Not only is it resistant to acids and alkalis, but by using phenol resin, melamine resin, xylene resin, etc. as the molding material, it does not spread even when exposed to flame, does not cause dull pink, and is in its original shape. It has excellent flame resistance properties such as maintaining the temperature of the tube and not emitting toxic gas, and also has excellent flame resistance properties such as not emitting toxic gas. The strength in the direction perpendicular to this is well balanced, resulting in excellent pressure resistance.

Examples of thermosetting resins used in the present invention include phenol resins, melamine resins, urea resins, unsaturated polyester resins, epoxy resins, silicone resins, allyl resins, xylene resins, and aniline resins. Among them, phenol resin, melamine resin and urea resin are preferably used.

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, etc. 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. These thermoplastic resins may contain additives commonly used in the molding of thermoplastic resins, such as stabilizers, fillers, processing aids, antioxidants, reinforcing agents, colorants, and lubricants. agents can be added.

A thermosetting resin pipe molded by the above-described method can be used to obtain a composite pipe coated with a thermoplastic resin by the above-described first method or second method.

Industrial applications: The composite tube thus obtained is made of a thermosetting resin with excellent heat resistance, flame resistance, corrosion resistance, etc. in the inner layer, and a thermoplastic resin with excellent impact resistance in the outer layer. , suitable as a fluid transfer tube.

Specifically, the composite pipe of the present invention can be used for liquid transfer in water supply pipes, hot water supply pipes, and drainage pipes in general houses, buildings, factories, hot springs, etc. (for example, in baths, water heaters, air conditioners, solar systems, etc.). Examples include water supply and drainage pipes, general drainage pipes, etc.), oil supply and drainage pipes for factories, vehicles, ships, aircraft, etc., and chemical transfer pipes.

In addition, for gas transfer, air pipes, ventilation pipes, exhaust pipes of general houses, buildings, factories, etc. (e.g. gas ranges, stoves, internal combustion engine air pipes, exhaust pipes, general ventilation pipes, general air supply pipes, general exhaust pipes, etc.) pipes, etc.), and gas transfer pipes for chemical factories (for example, nitrogen, argon, helium, etc.).

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

Reference Example 1 An extruder with a screw diameter of 30 mm and L/D = 22 has a diameter of 26 mm at the bottom of the screw, and a diameter of 26 mm at the tip following the measuring section.
A screw with a compression ratio of 2.0 and a smooth part with a mrn length of 105 mm (3.5D) was used, and a phenol resin (manufactured by Nippon Oil Seal Co., Ltd., trade name: Rogers RX-6684) was used as the molding material. The pipe was then continuously extruded.

The temperature inside the cylinder is C, (o~2D) = water cooling, C
2(3D~10■)) = 80°C, C'3(III)
-18D)=1oO℃, C4(19D~22D)=12
Extrusion molding was carried out at a temperature of 0° C. and a screw rotation speed of 35 rpm to obtain a pipe with an outer diameter of 30 mm and a wall thickness of 2.0 m.

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

The temperature of each part of the cylinder is C, - water cooling, C2 - 80'c
, C3 = 110°C, C4 = 120°C, and molding was carried out under the conditions of screw rotation speed 35 rpm, and the outer diameter was 30 m.
, I got a pipe with a wall thickness of 2.0 dragon.

Reference Example 3 Using the same extrusion equipment as Reference Example 1, phenol resin (manufactured by Sumitomo Bakelite Co., Ltd., product name PI) was used as the molding material.
VI-795J) was used to extrude into a pipe.

Temperature of each part of cylinder: C1 - water cooling, C2 - 80℃, C
32 105℃, C, :], 220℃, and molding was carried out under the conditions of screw rotation speed 35 rpm, outer diameter 30 m.
.

I got a No. 4 Eve with a thickness of 2.0.

Reference Example 4 Using an extruder with a diameter of 40 mm and L/'D = 24,
Scree? The diameter of the knee bottom is 35 m. Following the 3D measuring section, the diameter of the knee bottom is 35 m.
A screw with a smooth part of mm length 3D was used, and the molding material was made of phenolic resin (Sumitomo Bakelite @).
A pipe was extrusion molded using PM-795J (trade name). The temperature of each part of the cylinder is C1 (0-2D) = water cooling, C
2(3~10D)=60°C, C3(11~16D)=
80°C, C4(17~20D)=110°C, C5(zi
~24D) = 120℃, screw rotation speed 25
A pipe with an outer diameter of 40 mTL and a wall thickness of 2.5 mm was obtained at rpm.

Reference Example 5 Using the same extrusion device as Reference Example 1, melamine resin (manufactured by Otalite Co., Ltd., product name 0N-600) was used as the molding material.
The pipe was continuously extruded using

The temperature of each part of the cylinder is C14 cold, C2 = 85°C1C
Molding was carried out under the conditions of 52 115°C, C4 = 130'C, screw rotation speed 35 rpm, outer diameter 30 m.
I got a pipe with a wall thickness of 2.0 m.

Evaluation results: The compressive strength (direction perpendicular to the pipe axis, direction of the pipe axis, and ratio thereof) and hydraulic test results of the pipe obtained in the above manufacturing example were as shown in Table 1. .

Reference Example S Using the same extrusion device as Reference Example 1, epoxy resin (manufactured by Nippon Gosei Kako Co., Ltd., trade name: Alimerai) was used as the molding material.
The pipe was extruded using J=1060F). The temperature of each part of the cylinder is C44 cold, C2 = 85°C, C3
Molding was carried out under the following conditions: = 115° C., C = 125° C., and a screw rotation speed of 35 rpm to obtain a pipe with an outer diameter of 30 m and a wall thickness of 2.0 mm.

Production example 1 A water cooling jacket is provided at a length of 2D from the bottom of the hopper, and a heat control device is installed at each section (3 to 9D, 10 to 15D, and 16 to 19D), and furthermore, at a position 2D from the tip. 1 caliber 40mm, L/'D equipped with a coating device (length 5D) that allows thermoplastic resin to be supplied with a wall thickness of 1.5 mm.
Extruder (A) with a cylinder of = 24 (including the coating device part), a feed section 3D, a compression section 12D and a metering section with a screw bottom diameter of 35mm and a length of 4D followed by a diameter 35mm cylinder.
A screw with a compression ratio of 1.8 (B) having a smooth part with a dragon length of 5D and an extruder (C) with a diameter of 30 mm L/'D = 22 and equipped with a screw with a compression ratio of 2.5 were used to perform compounding. A tube was formed.

The extruder (C) is connected to the coating device part of the extruder (A) equipped with a screw (B), and the extruder (A) is used as a molding material.
Made of phenolic resin (Sumitomo Bakelite@), product name P
M-795J), polyvinyl chloride compound (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name Vinicron ER) in the extruder (C)
EK-1 (115) was introduced, and the extruder (A) was
~2D) two water-cooled, C2(3~9D)=8Q℃, C3(1
0~15D)=95°C, C4(16~1.9D)=1
10°C, coating device section (20-24D) = 180°C, screw rotation speed 25 rpm, extruder (C), C1 (O-
2D)=water cooling, C2(3-9D): 150°C, C3(1
0~16D)=170℃, C4(17~22D)=17
5℃, adapter = 180℃, screw rotation speed 45r
Extrusion was carried out under pm conditions, and the inner layer was made of phenolic resin with a diameter of 40 mm and a wall thickness of 2.5 mm, and the outer layer was made of polyvinyl chloride resin with a diameter of 41.5 mm and a wall thickness of 1.5 mm. A composite tube 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~IOD, 11~16D, 17~20D, and 21
~24I) with a diameter of 40 inches equipped with a thermal control device in each part
, by means of an extruder with a cylinder of L/D=24, a feed section 3D, a compression section 15D and a metering section with a screw bottom diameter of 35 mms and a length of 3D followed by a diameter of 35 mW.

A pipe was extruded using a screw having a smooth portion having a length of 3D using a molding material and a melamine-phenonyl resin (manufactured by Matsushita Electric Works, Ltd., trade name: ME-A).

The temperature of each part of the cylinder is C3 (0-2D) = water cooling, C2
(3~10D)=60℃, C3(11~16D)=85
°C, C4 (J7~20D) = 1.2 ('1 °C, C6 (2
1-24D) Set at 2130℃ and screw rotation speed 25
A pipe with an outer diameter of 40 mm and a wall thickness of 2.5 mm was extruded at rpm. This pipe was directly introduced into a crosshead die attached to an extruder with a diameter of 30 mm L/D = 22 and equipped with a screw with a V compression ratio of 3.0, and the temperature was set at Cl-180℃, c2 =210°QC3=220°C
Polypropylene resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name: Mitsui Noblen BET3-IJS) was coated with a wall thickness of 1.5 mm under the conditions of -220°C and screw rotation speed of 62 rpm. melamine-phenol resin with an outer diameter of 41.5 mm and a wall thickness of 1.5 mm, with an outer layer made of polypropylene resin with an outer diameter of 41.5 mm and a wall thickness of 1.5 mm.
A composite tube with a wall thickness of 4 mm was obtained.

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 Co., Ltd., trade name PM-795J) as a molding material. The temperature of each part of the cylinder is C, = cold, C
,,2=60'c,C1--80'C,C,=1 10
'cA Set C3=120℃, screw rotation speed 2
Molding is performed at 5 rpm to obtain an outer diameter of 40 mm and a wall thickness of 2.5 mm.
Obtained a phenol pipe.

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 fluid transfer tube.

[Note] Manufactured by IT Kogyo Co., Ltd., product name E (abbreviation) [Note] 2
The test method is JIS K 6742 K semi-L), increase the water pressure and read the pressure when the pipe breaks.

[Note] 3 A tube with a length of 5 cIIL was immersed in the test solution, 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. , 3 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. No. 1 Figure 1111111 Extrusion direction No. 2 Figure 3 Figure -111--1-H-Extrusion direction No. 4 Procedural amendments August 1982 24th Japan Patent Office Commissioner Manabu Shiga 1, Indication of the case Patent Application No. 81079 of 1981 2, Name of the invention Synthetic resin composite pipe for fluid transfer 3, Person making the amendment Relationship to the case Patent applicant 4, Amendment Date of order: July 31, 1980 (shipment date) (1) On page 23, line 7 of the specification, the word "each" has been replaced with "filling of each cross section in the direction of the tube axis and in the direction perpendicular to the tube axis." It is corrected to "concerning the shape of the fibers". Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (1)

[Scope of Claims] 1) A synthetic resin composite tube for fluid transfer, which is made by coating a thermoplastic resin on the surface of an extruded thermosetting resin tube in which resin and/or filler are oriented in irregular directions. . 2) A synthetic resin composite tube for fluid transfer directly to the tube axis of the thermoplastic resin tube forming the inner layer. 3) A patent in which a screw with a smooth part at the tip is used, a thermosetting resin is shaped to the extent that it can maintain its own shape in the smooth part, and the surface is coated with a thermoplastic resin. A synthetic resin composite tube for fluid transfer according to claims 1 and 2.