JPH0596601A - Manufacture of fluorine-based composite tube - Google Patents

Abstract

PURPOSE:To efficiently manufacture flexible tube by a method wherein fluorine- based thermoplastic elastomer for forming the inner peripheral surface layer of the tube, general-purpose non-rigid thermoplastic resin for forming the outer peripheral surface layer of the tube and adhesive for both the resins as intermediate layer are extruded respectively through a common head die from respective extruders for manufacturing the tube for transferring ultrapure water or the like. CONSTITUTION:Fluorine-based thermoplastic elastomer layer 5 is formed by extruding fluorine-based thermoplastic elastomer for forming the inner peripheral surface layer of the tube concerned from a first extruder 1 through a common head came 4. Next, adhesive such as acrylic alkyl ester or the like is extruded from a third extruder 3 through the head die 4 so as to form bonding layer 6 on the outer peripheral surface of the fluorine-based thermoplastic elastomer layer 5. Next, general-purpose non-rigid thermoplastic resin selected from vinyl chloride-based resin group is extruded from a second extruder 2 so as to form general-purpose non-rigid thermoplastic resin layer 7 as the outer peripheral surface layer of the tube concerned in order to make tire three layers into an integral body.

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 fluorine-based composite tube, and more particularly to a method for manufacturing 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, polyvinylidene fluoride resin (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 the above-mentioned fluorine-based thermoplastic resin. 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]

[Means for Solving the Problems] That is, according to the present invention, by using an equipment consisting of three extruders and one head die common to them, a fluorine-based thermoplastic resin is produced by the first extruder. A common head is prepared by extruding an elastomer, a general-purpose soft thermoplastic resin by a second extrusion molding machine, and an adhesive resin that adheres the fluorine-based thermoplastic elastomer and the general-purpose soft thermoplastic resin by a third extrusion molding machine. -By being introduced into the die, the extrudate from the first extruder is the inner surface layer of the tube, the extrudate from the second extruder is the outer surface layer of the tube, and the third extruder is The present invention relates to a method for producing a fluorine-based composite tube, which comprises subjecting an extruded product to ternary coextrusion molding so as to form an adhesive layer between inner and outer peripheral layers.

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.

The adhesive resin used in the present invention forms an adhesive layer between a fluorine-based thermoplastic elastomer layer and a general-purpose soft thermoplastic resin layer. For example, acrylic acid alkyl ester (alkyl group: methyl, ethyl, propyl). Or a butyl group) and a methacrylic acid alkyl ester (alkyl group: same as above), a homopolymer of a monomer group or a copolymer of two or more monomers of these monomer groups, and ethylene-acetic acid. Examples of the thermoplastic resin include a vinyl copolymer (hereinafter abbreviated as EVA), and these may be 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. Three extruders 1, 2, 3 and one head common to these
Using the equipment consisting of the die 4, the first extruding machine 1 adheres the fluoroplastic elastomer, the second extruding machine 2 adheres the general-purpose soft thermoplastic resin, and the third extruding machine 3 adheres them. Resin is extruded and introduced into a common head die 4, and the extrudate from the first extrusion molding machine 1 forms the inner peripheral surface layer of the tube, and the extrudate from the second extrusion molding machine 2 forms the outer peripheral surface layer. The ternary coextrusion molding is performed so that the extruded product by the third extruder 3 forms an adhesive layer between the inner peripheral surface layer and the outer peripheral surface layer.

As described above, as shown in FIG. 2, the fluorine-based thermoplastic elastomer layer 5 and the adhesive layer (adhesive resin layer).
A composite tube in which 6 and the general-purpose soft thermoplastic resin layer 7 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 The cylinder temperature of the first 32 mmφ extruder (UT-32-H, manufactured by Plastic Engineering Laboratory Co., Ltd.) was set to 230.
To 280 ° C., and block-copolymerize vinylidene fluoride-hexafluoropropylene random copolymer as a soft segment and tetrafluoroethylene-ethylene random copolymer as a hard segment in the hopper of the extruder. Specific gravity 1.89 (ASTM
D792) and a melting point of 220 ° C. (ASTM D3418), a fluorine-based thermoplastic elastomer is added, and the second 65
A cylinder temperature of an mmφ extruder (FS65, manufactured by Ikegai Tekko Co., Ltd.) was set to 155 to 185 ° C., and a lead-based heat stabilizer (Tribase TL7000, manufactured by Sakai Chemical Industry Co., Ltd.) was added to the hopper of the extruder. Blended average degree of polymerization 2
350 (JIS K6721) vinyl chloride resin (Kanefuchi Chemical Industry Co., Ltd., Kanevinyl S2300) 100
80 parts by weight of di-2-ethylhexyl phthalate
3 parts by weight of a soft vinyl chloride resin composition containing 20 parts by weight of calcium carbonate and 3 parts by weight of a 32 mmφ extruder (Plastic Engineering Laboratory Co., Ltd., UT-32-).
The cylinder temperature of H) is set to 175 to 185 ° C., and the hopper of the extruder is a copolymer containing methyl methacrylate as a main component and containing 0.3 g of the polymer.
The specific viscosity of 0 ml of DMF solution measured at 30 ° C is 0.08.
The above-mentioned extrudates are introduced into a head / die (set temperature: 210 ° C.) common to the above-mentioned three extruders and extruded by the first extruder. Has a wall thickness of 0.3 to 0.4 mm as the inner peripheral surface layer of the tube, and the extrudate produced by the second extruder has a wall thickness of 2.4 to 2.6 mm as the outer peripheral surface layer of the tube. A composite tube having an inner diameter of 44 mm and an outer diameter of 50 mm in which an extrudate produced by the above-mentioned extrusion molding machine was formed as an adhesive layer between the inner and outer peripheral surface layers to have a wall thickness of 0.1 to 0.2 mm was obtained.

Example 2 Using the equipment used in Example 1, the extrudates and extrusion conditions in the first extruder and the second extruder were the same as in Example 1, and the third extrusion molding was performed. The cylinder temperature of the machine is set to 165 to 175 ° C., the specific gravity of 1.07 (JIS K6760), the melt index (190 ° C., 10 Kg / cm ² ) 40 g / 10 minutes is set in the hopper of the extruder.
EVA having a vinyl acetate content of 70% by weight was charged and extruded. The conditions such as the temperature and shape of the common head die were set to be the same as in Example 1 to obtain a composite tube having the same size and shape as in Example 1.

COMPARATIVE EXAMPLE 1 A first 32 mmφ extruder (Plastic Engineering Laboratory Co., Ltd., UT-32-H) was used, using equipment consisting of two extruders and one common head die. ) Is set to 210 to 240 ° C. and 100 parts by weight of the same fluorine-containing thermoplastic elastomer as that used in Example 1 is used in the hopper of the extruder to contain methyl methacrylate as a main component. A copolymer having a specific viscosity of 1.4 in 100 ml of a toluene solution containing 0.4 g of the copolymer measured at 30 ° C. (Kaneace PA-20, manufactured by Kanegafuchi Chemical Industry Co., Ltd.) 20% by weight of a fluorinated thermoplastic elastomer composition is added and extruded, and at the same time, the cylinder temperature of the second 65 mmφ extruder (FS65, manufactured by Ikegai Tekko KK) is set to 155 to 185 ° C.
The same soft vinyl chloride resin composition as that used in Example 1 was charged into the hopper of the extruder and extruded, and these extrudates were mixed with a common head die (set temperature: 240 ° C.). ), The extrudate from the first extruder is used as the inner peripheral surface layer of the tube with a thickness of 0.3 to 0.4 mm, and the extrudate from the second extruder is used as the outer peripheral surface layer of the tube. Internal diameter 44 formed to a wall thickness of 2.6 to 2.7 mm
A composite tube having an outer diameter of 50 mm and an outer diameter of 50 mm was obtained.

Comparative Example 2 Using the equipment used in Comparative Example 1, the cylinder temperature of the first extruder was set to 230 to 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. Has an inner surface layer of 0.3 to
A composite tube having an inner diameter of 44 mm and an outer diameter of 50 mm in which the extrudate produced by the second extrusion molding machine was formed as the outer peripheral surface layer to a thickness of 0.4 mm to a thickness of 2.6 to 2.7 mm was obtained.

A test piece for cutting the composite tubes obtained in Examples 1 and 2 and Comparative Examples 1 and 2 to measure the tensile shear strength of the adhesive surface between the inner peripheral surface layer and the outer peripheral surface layer is shown in FIG. 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. for 5 hours.
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 3 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. Next, 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 1 hour.
After filling 50 ml, both ends were sealed and shaken at 60 ° C. for 24 hours.
The TOC of ultrapure water in these tubes is specified by JIS K05.
The measurement was performed by the method of No. 51, 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.

[0018]

[Table 1]

[0019]

As described above, according to the method of the present invention, a composite in which an adhesive layer is provided between the inner peripheral surface layer made of a fluoroplastic elastomer and the outer peripheral surface layer made of a general-purpose soft thermoplastic resin The tube can be efficiently manufactured, and the obtained composite tube has the inner peripheral surface layer and the outer peripheral surface layer firmly bonded to each other by the adhesive layer, which has flexibility and is easy to lay a curved portion. Therefore, it can be suitably used as a device for transferring ultrapure water or the like and has a high industrial value.

[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 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 2nd extrusion molding machine 3 3rd extrusion molding machine 4 Crosshead die 5 Fluorine type thermoplastic elastomer layer 6 Adhesive layer (adhesive resin layer) 7 General-purpose soft thermoplastic resin layer

Claims (4)

[Claims] 1. Three extruders and one common to them
Using the equipment consisting of the base head and die, the first extrusion machine produces a fluoroplastic elastomer, the second extrusion machine produces a general-purpose soft thermoplastic resin, and the third extrusion machine produces the above-mentioned fluorine. By extruding the adhesive resin for adhering the thermoplastic thermoplastic elastomer and the general-purpose soft thermoplastic resin and introducing them into the common head die, the extrudate produced by the first extrusion molding machine produces the inner peripheral surface layer of the tube,
The ternary coextrusion is performed so that the extrudate from the second extruder forms the outer peripheral surface layer of the tube and the extrudate from the third extruder forms an adhesive layer between the inner and outer peripheral surface layers. A method for producing a fluorine-based composite tube, which is characterized. 2. The 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 a polyolefin resin. 4. A homopolymer of a monomer group in which the adhesive resin comprises an alkyl acrylate and an alkyl methacrylate, a copolymer of two or more monomers of these monomer groups, and ethylene- The method according to claim 1, 2 or 3, which is at least one selected from the group consisting of vinyl acetate copolymers.