JPH0596599A - Manufacture of composite tube of fluoroelastomer - Google Patents

Abstract

PURPOSE:To use the title composite tube preferably as a tool having flexibility and transferring ultra-pure water, etc., by a method wherein a fluorine plastic elastomer is extrusion-molded in a tubular shape by a first extrusion molding machine and cooled and dried, and coated with adhesives, and a general-purpose flexible thermoplastic resin is extrusion-molded onto an outer circumferential surface by a second extrusion molding machine. CONSTITUTION:A fluorine thermoplastic elastomer is extruded in a tubular shape from a first extrusion molding machine 1. An extruded tube 2 is cooled with a cooling device 3 continuously, and dried continuously by a drier 4. The dried tube 2 is forwarded to an adhesive coater 5, and the surface of the tube 2 is coated continuously with adhesives. The tube 2 coated with adhesives is passed in the crosshead-die 7 of a second extrusion molding machine 6 installed at an approximately right angle in the progressive direction of the tube 2, thus extrusion-coating the outer circumferential surface of the tube 2 with a general-purpose flexible thermoplastic resin, then manufacturing a composite tube 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fluorine-based composite tube, and more particularly to a method for producing a fluorine-based composite tube suitable for transferring ultrapure water or the like.

[0002]

2. Description of the Related Art With the recent remarkable development of the semiconductor device-related industry, the amount of ultrapure water used has increased and the demand for pipes for transferring ultrapure water has increased rapidly. Conventionally, many proposals have been made to use a pipe as a device for transferring ultrapure water. One of them is, for example, a vinylidene fluoride polymer (hereinafter referred to as PVDF) in order to prevent contamination of the water quality of ultrapure water. There is an attempt to use a pipe made of a fluorine-based thermoplastic resin such as. However, since these resins are extremely expensive, inexpensive resin such as vinyl chloride resin or ABS resin is used as most of the material including the outer peripheral surface of the pipe with these resin layers only on the inner peripheral surface of the pipe. An improved method is proposed.

Such a pipe in which two kinds of materials are combined is disclosed in, for example, Japanese Patent Laid-Open No. 61-171983 and Japanese Utility Model Laid-Open No. 61-164730. In particular, in Japanese Utility Model Application Laid-Open No. 61-164730, in order to improve the interfacial adhesion between the inner peripheral surface layer and the outer peripheral surface layer, 1) PVDF used as the material of the inner peripheral surface layer and the material of the outer peripheral surface layer are used. One or both of the general-purpose thermoplastic resins is copolymerized with an ethylenically unsaturated carboxylic acid ester, or a polymer of an ethylenically unsaturated carboxylic acid ester or a copolymer with another copolymerizable monomer is used. Method of inclusion,
2) A method of providing an adhesive layer (adhesive, pressure-sensitive adhesive, etc.) between the inner peripheral surface layer and the outer peripheral surface layer is proposed. However, if a pipe is used as a device for transferring ultrapure water,
There is no particular problem in the construction of the straight part in the laying work, but complicated construction using joints etc. is required in the curved part, so an alternative device for pipes that can be freely and easily constructed even in curved parts is desired. It was rare.

On the other hand, Japanese Utility Model Laid-Open No. 61-1 regarding a two-layer pipe.
No. 64730, PV, which is the material of the inner peripheral surface layer to improve the adhesion of the two layers.
The method 1) of incorporating the ethylenically unsaturated carboxylic acid ester component into a fluorine-based thermoplastic resin such as DF by a copolymerization method or a blending method of a polymer of the ester includes ultrapure water of the fluorine-based thermoplastic resin. However, if only the general-purpose thermoplastic resin of the outer peripheral surface layer is modified by the above method in order to avoid this problem, the adhesion between the two layers becomes insufficient. . Also,
Japanese Utility Model Application Laid-Open No. 61-164730 does not disclose a specific method for providing an adhesive layer between two layers 2) by providing an adhesive layer by an extrusion molding method.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve both of the following two problems associated with conventional equipment for transferring ultrapure water. 1) Development of alternative equipment for pipes that can complicate the construction of curved sections. 2) Development of a method for providing a strong adhesive layer between the inner peripheral surface layer made of a fluoroplastic and the outer peripheral surface layer made of a general-purpose thermoplastic resin.

[0006]

That is, the present invention uses two extruders to continuously extrude a fluorinated thermoplastic elastomer into a tube by the first extruder to form the tube. After being continuously cooled and dried, an adhesive was continuously applied to the surface of the tube and passed through a crosshead die of a second extruder, which was installed almost at right angles to the traveling direction of the tube. Then, the method for producing a fluorine-based composite tube is characterized in that a general-purpose soft thermoplastic resin is extruded on the outer peripheral surface of the tube by a second extruder.

The fluorine-based thermoplastic elastomer used in the present invention comprises a block copolymer of a fluorine-based soft segment and a fluorine-based hard segment. For example, vinylidene fluoride as the fluorine-based soft segment.
Block copolymer of hexafluoropropylene random copolymer and tetrafluoroethylene-ethylene random copolymer as a fluorine-based hard segment, vinylidene fluoride-hexafluoropropylene random copolymer and fluorine-based as a fluorine-based soft segment A block copolymer with a vinylidene fluoride polymer as a hard segment and the like, which are used alone or in combination of two or more kinds.

The general-purpose soft thermoplastic resins used in the present invention include soft vinyl chloride resin compositions and olefin resins. The soft vinyl chloride resin composition means at least one plasticizer selected from the vinyl chloride resin group consisting of a vinyl chloride resin and a copolymer of a vinyl chloride monomer and a monomer copolymerizable therewith. Are added, and if necessary, an elastomer such as nitrile butadiene rubber and ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) and an inorganic filler such as calcium carbonate, talc and clay are compounded. can do. The olefin-based resin is EVA, ethylene- (meth) acrylic acid alkyl ester (alkyl group carbon number: 4 to 8) copolymer, chlorinated polyethylene, or the like. These are used alone or in combination of two or more.

A method of manufacturing the fluorine-based composite tube of the present invention will be described with reference to FIG. 1 showing manufacturing equipment. The fluorine-based thermoplastic elastomer is extruded from the first extruder 1 into a tube shape. The extruded tube 2 is continuously cooled by the cooling device 3 and then continuously dried by the drying device 4. As the cooling device 3, a system of passing a tube through a cooling water tank, a system of showering cooling water on the tube, or the like is used. As the drying device 4, a heater, a hot air blowing machine, or the like is used. The dried tube 2 is sent to the adhesive application device 5, and the adhesive is continuously applied to the surface of the tube. As the adhesive application device 5, for example, as shown in FIG. 3, a system of spraying the adhesive 8 onto the surface of the tube 2 by a spray gun 9, a system of passing the tube through an adhesive tank, or the like is used. To use.

Next, the tube 2 coated with the adhesive is
Passing through the crosshead die 7 of the second extruder 6 installed at a substantially right angle to the traveling direction of the tube,
The general-purpose soft thermoplastic resin 8 is made by the second extruder 6.
Of the composite tube 10 by extrusion coating the outer peripheral surface of the tube 2.
And

As described above, as shown in FIG. 2, a composite tube in which the fluorine-based thermoplastic elastomer layer 11, the adhesive layer 12, and the general-purpose soft thermoplastic resin layer 13 are laminated in this order is obtained.

[0012]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto. Example 1 First 40 mmφ extruder (FS manufactured by Ikegai Tekko KK
Set the cylinder temperature of 40) to 230-280 ° C,
In the hopper of the extruder, a vinylidene fluoride-hexafluoropropylene random copolymer as a soft segment and a tetrafluoroethylene-ethylene random copolymer as a hard segment were block-copolymerized with a specific gravity of 1.89 (ASTM). D792), melting point 22
A 0 ° C (ASTM D3418) thermoplastic fluorinated elastomer is added to extrude a tube having an inner diameter of 44 mm and an outer diameter of 46 mm, and the tube is continuously cooled by a shower ring of cooling water and then blown with hot air. And continuously dried, and then an adhesive (EP-001, manufactured by Cemedine Co., Ltd.) in which the main agent and the curing agent were sufficiently mixed in advance in a weight ratio of 1: 1 to be uniform was applied by an applicator shown in FIG. The coating was continuously applied to the surface of the tube and passed through a crosshead die of a second 50 mmφ extrusion molding machine (FS50 manufactured by Ikegai Tekko KK) installed at a right angle to the traveling direction of the tube.

On the other hand, the cylinder temperature of the second extruder is set to 155 to 185 ° C., and the hopper of the extruder is charged with a lead-based heat stabilizer (Tribase T manufactured by Sakai Chemical Industry Co., Ltd.).
L7000) blended with an average degree of polymerization of 1250 (JIS
K6721) vinyl chloride resin (Kanefuchi Chemical Co., Ltd., Kanevinyl S1003) 100 parts by weight of di-2-ethylhexyl phthalate 80 parts by weight and calcium carbonate 20 parts by weight of a soft vinyl chloride resin composition. The flexible vinyl chloride resin composition is adhered to the outer peripheral surface of the fluorothermoplastic elastomer tube whose surface is coated with the adhesive passing through the crosshead die and having a thickness of about 2 mm. Extrusion molding, inner diameter 44m
A composite tube with m and an outer diameter of 50 mm was obtained.

Example 2 Using the equipment used in Example 1, the cylinder temperature of the first extruder was set to 230-280 ° C., and the hopper of the extruder was used in Example 1. The same fluorine-based thermoplastic elastomer as that used is added, and the inner diameter is 44 m.
After extruding a tube with m and an outer diameter of 46 mm and continuously cooling this tube with a shower ring of cooling water,
Hot air was blown to dry continuously, and then the same adhesive as that used in Example 1 was continuously applied to the tube surface by an applicator, and the tube was placed at right angles to the traveling direction of the tube. It was passed through the crosshead die of a No. 2 extruder.

On the other hand, the cylinder temperature of the second extruder is set to 130 to 145 ° C. and the melt index (190 ° C., 10 Kg / cm ² ) 30 g is set in the hopper of the extruder.
/ 10 minutes, EVA having a vinyl acetate content of 33% by weight is charged and extruded, and the EVA that has passed through the crosshead die is applied to the outer peripheral surface of the tube of the fluorine-based thermoplastic elastomer coated on the surface. A composite tube having an inner diameter of 44 mm and an outer diameter of 50 mm was obtained by adhering to a wall thickness of about 2 mm and extruding.

COMPARATIVE EXAMPLE 1 A first 40 mmφ extruder (FS40 manufactured by Ikegai Tekko KK) was operated at a cylinder temperature of 210 by using an equipment consisting of two extruders and a common head die. ~ 2
Example 1 was set in the hopper of the extruder set at 40 ° C.
100 parts by weight of the same fluorine-based thermoplastic elastomer as used in 1., which is a copolymer containing methyl methacrylate as a main component and containing 0.4 g of the copolymer.
A copolymer having a specific viscosity of 1.4 in ml of a toluene solution measured at 30 ° C. (Kaneace Chemical Co., Ltd.
PA-20) was mixed with 20 parts by weight of a fluorine-containing thermoplastic elastomer composition and extruded, and at the same time, the second 50
A cylinder temperature of an mmφ extruder (FS50, manufactured by Ikegai Tekko Co., Ltd.) was set to 155 to 185 ° C., and the same soft vinyl chloride resin composition as that used in Example 1 was placed in the hopper of the extruder. After being charged and extruded, these extrudates are introduced into a common head die (set temperature: 240 ° C.), and the extrudate produced by the first extruder is used as an inner peripheral surface layer.
The inner diameter is 44 mm and the outer diameter is 50 mm, and the extrudate produced by the second extruder has a thickness of 2 mm and has a thickness of 2 mm as the outer peripheral surface layer.
A composite tube of

Comparative Example 2 Using the equipment used in Comparative Example 1, the cylinder temperature of the first extruder was set to 230-280 ° C. and the hopper of the extruder was used in Example 1. The same fluoro-thermoplastic elastomer as that used is charged and extruded, and at the same time, the cylinder temperature of the second extruder is set to 155 to 185.
C. and 100 parts by weight of the same soft vinyl chloride resin composition as used in Example 1 was added to the hopper of the extruder, and the same methyl methacrylate-based copolymer as used in Comparative Example 1 was used. A soft vinyl chloride resin composition containing 20 parts by weight of a polymer is charged and extruded, and these extrudates are introduced into a common head die (set temperature: 250 ° C.) and extruded by a first extruder. To obtain a composite tube having an inner diameter of 44 mm and an outer diameter of 50 mm, in which the inner peripheral surface layer was 1 mm thick and the extruded product from the second extruder was formed as the outer peripheral surface layer having a thickness of 2 mm.

FIG. 4 shows a test piece for cutting the composite tubes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 and measuring the tensile shear strength of the bonding surface between the inner peripheral surface layer and the outer peripheral surface layer. Five pieces were prepared for each of the examples and comparative examples according to the shape shown, and these were left in a thermostatic chamber at 23 ° C. for 48 hours and then at 5 ° C.
Tensile at a speed of 00 mm / min, the strength at the time of breaking the adhesive layer was measured by an autograph, and the average value of the obtained five measured values was calculated. The measurement results are shown in Table 1.

The composite tubes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 were cut into tubes each having a length of 15 cm.
This was produced and the following operations were performed in a clean room to evaluate the contamination with ultrapure water. First, the total organic carbon concentration (hereinafter referred to as TOC) is 8 pp on the inner surface of these tubes.
After wiping well with ultrapure water which is b, liquid cleaner (Daiichi Clean Chemical Co., Ltd.,
Product name: Scat 20X-PF5% solution) 150ml
The tube was put in, both ends of the tube were sealed, and the tube was shaken for 4 hours on a shaker. Then, the inner surface of the tube was washed for 2 hours while allowing the ultrapure water to overflow, and then the ultrapure water was placed in the tube for 15 hours.
It was filled with 0 ml, sealed at both ends, and shaken at 60 ° C. for 24 hours. The TOC of ultrapure water in these tubes is specified by JIS K055.
The measurement was performed by the method 1 and the average value of the obtained three measured values was calculated. As a reference, the TOC of a commercially available vinyl chloride resin pipe was also measured. The results of these analyzes are shown in Table 1.

[0020]

[Table 1]

[0021]

As described above, according to the method of the present invention, the adhesive layer is provided between the inner peripheral surface layer composed of the fluorine-based thermoplastic elastomer and the outer peripheral surface layer composed of the general-purpose soft thermoplastic resin. The composite tube has flexibility and is easy to lay a curved portion, so that it can be suitably used as a device for transferring ultrapure water or the like, and is industrially valuable.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of manufacturing equipment used in the present invention.

FIG. 2 is a schematic sectional view of a fluorine-based composite tube of the present invention.

FIG. 3 is a schematic view of an adhesive applicator used in Examples 1 and 2.

FIG. 4 is a schematic view showing the shape of a test piece for measuring tensile shear strength of an adhesive portion of a fluorine-based composite tube.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st extrusion molding machine 2 Tube 3 Cooling apparatus 4 Drying apparatus 5 Adhesive application apparatus 6 2nd extrusion molding machine 7 Crosshead die 8 Adhesive 9 Spray gun 10 Composite tube 11 Fluorine-based thermoplastic elastomer layer 12 Adhesive layer 13 General-purpose soft thermoplastic resin layer

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Claims (3)

[Claims] 1. A fluoroplastic elastomer is continuously extruded into a tube shape by a first extruder using two extruders, and the tube is continuously cooled and dried. , The adhesive is continuously applied to the surface of the tube, and the adhesive is installed at a right angle to the traveling direction of the tube.
Of the extrusion molding machine, and a general-purpose soft thermoplastic resin is extruded on the outer peripheral surface of the tube by a second extrusion molding machine. 2. The production method according to claim 1, wherein the fluorinated thermoplastic elastomer is a block copolymer of a fluorinated soft segment and a fluorinated hard segment. 3. The method according to claim 1, wherein the general-purpose soft thermoplastic resin is at least one selected from the group consisting of a soft vinyl chloride resin composition and an olefin resin.