JPH07100994A - Polyallylene sulfide multilayer tube and tube joint - Google Patents

Abstract

PURPOSE:To obtain a tube and a tube joint which has excellent manufacturing properties and in which flow-out or eluation of metal content and TOC are small by forming an inner layer in contact with fluid of a multilayer tube of polyallylene sulfide and a specific amount of resin or rubber. CONSTITUTION:An inner layer in contact with fluid of a multilayer tube for forming a short tube 1 is formed of 80-100wt.% of polyallylene sulfide and 0-20wt.% of other resin or rubber. As the rubber, impact resistance of silicone elastomer, acrylic elastomer, olefin elastomer, polyamide elastomer, etc., is preferably used. An outer layer of the tube is formed of at least one of colorant and ultraviolet absorbent and polyallylene sulfide. The tube can be formed by a co-extrusion molding method, a combined adapter method, and a multilayer tube joint can be formed by a known multilayer injection molding method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer pipe and multi-layer pipe joint made of polyarylene sulfide, which is useful as a piping material for fluids such as ultrapure water.

[0002]

BACKGROUND ART Synthetic resin tubes such as vinyl chloride, polyvinylidene fluoride, and tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer are widely used as piping materials for ultrapure water used in semiconductor manufacturing processes. However, vinyl chloride lacks the heat resistance that can be sterilized with warm pure water close to 100 ° C, and polyvinylidene fluoride has a large amount of total organic carbon (TOC), and tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer is manufactured. Both have poor properties and are expensive, and all have drawbacks.

In recent years, as a piping material for this ultrapure water, it has a heat resistance and high mechanical characteristics such that it can be sterilized with warm pure water close to 100 ° C. to prevent contamination with bacteria and the like, and metal compounds, metal ions, etc. Japanese Unexamined Patent Publication No. 62-215186 proposes a pipe material made of a polyetheretherketone resin having less metal elution and TOC.

However, the above-mentioned Japanese Patent Laid-Open No. 62-2151.
The polyether ether ketone resin disclosed in No. 86 is expensive. Therefore, there is a demand for a piping material for ultrapure water that is more manufacturable and can be obtained at low cost.

It is excellent in manufacturability, can be obtained at a lower cost, and is similar to the polyether ether ketone resin,
Polyarylene sulfide, which has properties such as heat resistance, chemical resistance, and high mechanical properties, can be mentioned. However, even when irradiated for a relatively short time with a fluorescent lamp, the irradiated surface was colored and changed significantly. It has a drawback that it gives an impression like that. Even if a colorant, an ultraviolet absorber, or the like is added to solve the problem, they cause the outflow or elution of the metal component into the ultrapure water, or cause an increase in TOC in the pure water, which is not preferable. .

[0006]

In view of the above points, the present invention is a resin having excellent manufacturability, which has a small change in appearance,
It is an object of the present invention to provide a pipe and a pipe joint having less outflow or elution of metal components and less TOC.

[0007]

The gist of the present invention is that the outer layer comprises at least one of a colorant and an ultraviolet absorber and polyarylene sulfide, and the inner layer in contact with a fluid comprises 80 to 100% by weight of polyarylene sulfide. A polyarylene sulfide multi-layer pipe characterized by comprising 0 to 20% by weight of another resin or rubber and a multi-layer pipe joint having the same structure. Hereinafter, the present invention will be described in detail.

In the present invention, the outer layer comprises at least one of a colorant and an ultraviolet absorber and polyarylene sulfide. Here, the outer layer does not mean the outermost layer, but the layer outside the inner layer described later.

In the present invention, the polyarylene sulfide means a polymer whose main constituent is-(-Ar-S-)-(where "-Ar-" means an arylene group). . Here, the arylene group is used in a broad sense, and includes p-phenylene, m-phenylene, 2,6-naphthylene, 4,4'-biphenylene, and -Ph-C.
O-Ph-, (here, "-Ph-" means a phenylene group. The same applies hereinafter), -Ph-O-Ph, -Ph-CH.
_It includes a divalent aromatic residue containing at least two aromatic rings having 6 carbon atoms, such as _2- Ph-, -Ph-SO2-Ph- and the like. A substituent such as an alkyl group or a carboxyl group may be introduced into each aromatic ring. Further, these may be homopolymers, random copolymers, or block copolymers.

Among these, those having a phenylene group, particularly a paraphenylene group as a main constituent element are preferable. The term “main constituent element” as used herein means that —Ar—S— is 50 mol% or more.
It is preferably 70 mol% or more, and more preferably 90 mol% or more. The polyarylene sulfide may be linear or crosslinked, but preferably a substantially linear and high molecular weight one is used. Here, the substantially linear high molecular weight polyarylene sulfide refers to a solvent in which 0.1 g or more is dissolved in 1 dl of the solvent which is most dissolved at a temperature 50 ° C. lower than the melting point of the resin. For example, when the polyarylene sulfide is polyphenylene sulfide, it has a solubility of 0.1 g or more in 1 dl of α-chloronaphthalene at 230 ° C.

The outer layer contains at least one of a colorant and an ultraviolet absorber in addition to the above polyarylene sulfide. These additives can be used alone or in combination of two or more, and the total amount of the additives is preferably 5% or less. In addition to these, for example, impact-resistant agents such as silicone-based elastomers, acrylic-based elastomers, olefin-based elastomers and polyamide-based elastomers, fibers such as glass fibers, carbon fibers and ceramic fibers, antistatic agents, heat stabilizers, etc. are included. May be.

On the other hand, the inner layer in contact with the fluid comprises 80 to 100% by weight of polyarylene sulfide and 0 to 20% by weight of another resin or rubber. Although polyarylene sulfide alone is preferable, other resin or rubber may be contained in a small amount, and a composition composed of 90% by weight or more and 10% by weight or less of other resin or rubber is relatively preferably used. Among them, polyarylene sulfide 9
A composition consisting of 0 to 98% by weight and 2 to 10% by weight of rubber is more preferably used. As the rubber, for example, a shock-resistant agent such as a silicone-based elastomer, an acrylic-based elastomer, an olefin-based elastomer, or a polyamide-based elastomer is preferably used.

The multi-layer pipe and the multi-layer pipe joint of the present invention may be composed of only two layers, the inner layer and the outer layer, but one layer or two or more layers may be interposed between the inner layer and the outer layer. Examples of such layers include fiber-reinforced polyarylene sulfides such as glass fibers, carbon fibers or ceramic fibers. Also, one or two layers are provided outside the outer layer
There may be more than one layer. An example of such a layer is a heat shrink film. However, what consists of only the inner layer and the outer layer has the same kind of polyarylene sulfide as the matrix resin, and it is possible to join easily and firmly by butt welding without providing an adhesive layer,
It is easy to mold and is preferably used.

In the present invention, the ratio of the thickness of layers other than the inner layer to the thickness of the inner layer is preferably 5/95 to 70/3.
0, more preferably 10/90 to 60/40, and particularly preferably 20/80 to 50/50. If the thickness of the layers other than the inner layer is less than 5% of the total thickness, the effect of preventing discoloration due to deterioration by light is weakened, which is not preferable.
If the thickness of the layers other than the inner layer exceeds 70% of the total thickness, the bead portion formed during welding pushes the layer portion other than the inner layer to the bead portion inside the pipe, and the bead portion There is a concern that the additive may flow out into the fluid such as ultrapure water from the surface exposed to the surface, or the metal component or TOC in the pipe fluid may increase due to elution from the additive into the fluid, which is not preferable.

The multilayer pipe of the present invention can be formed by a coextrusion molding method, a combined adapter method, a multi-manifold method, etc., and the multilayer pipe joint of the present invention can be formed by a known multilayer injection molding method.

The multi-layer pipes of the present invention or the multi-layer pipe of the present invention and the multi-layer pipe joint of the present invention can be joined easily and firmly by welding by a known non-contact heating method. At that time, it is preferable to adopt various preventive measures such as a groove method and a welding method using a core in order to reduce the bead amount on the inner surface.

[0017]

【Example】

Example 1 Polyphenylene sulfide (using "Fortron KPS W-300" manufactured by Kureha Chemical Industry Co., Ltd.) as an inner layer, and carbon black "MA- manufactured by Mitsubishi Kasei Co., Ltd."
A polyphenylene sulfide (using the same material as the inner layer material) composition containing 0.5% by weight of 100 "as an outer layer,
A two-layer pipe having a nominal diameter of 25 mm, a wall thickness of 3.6 mm, and a wall thickness ratio of the outer layer to the inner layer of 1: 2 was formed by coextrusion.

Light resistance tester ("HP-UV" manufactured by Atlas)
The surface of the two-layer tube is irradiated with a room light for 3 years, and a color difference meter (“TC-1800MK” manufactured by Tokyo Denshoku Co., Ltd.) is used.
II ”) was used to measure the ΔE on the surface of the two-layer pipe.
Was 10 or less, and almost no change was observed.

Further, a short tube 1 having a length of 1 m including a welded portion is cut out from the two-layer tube, and one end corresponding to the lower end shown in the figure is sealed as shown in FIG. 1 to be a measurement object. Ultrapure water was put in, and the other end was also capped so as not to be mixed from the outside. This was applied to a dissolution test apparatus 3 as shown in FIG. 1 to perform a short pipe water sealing test at 80 ° C. In the device 3, a fixed amount of water is controlled by the electric heater 5 to a constant temperature by the makeup water 4, and the space in the device is filled with the nitrogen gas 2. The amount of metal components and the amount of TOC on the 30th sealing day were comparable to those of the single-layer tube composed only of polyphenylene sulfide. In addition, the amount of metal component is fluorescent X-ray (“MES manufactured by Horiba Ltd.
The amount of TOC was measured by “TOC5000” manufactured by Shimadzu Corporation.

Example 2 The outer layer was made of polyphenylene sulfide (Kureha Chemical Industry Co., Ltd.)
"Fortron KPS W-300" manufactured by Daifeng Seika Co., Ltd., which is copper cyanine blue, is used.
Example 1 was repeated except that the composition contained 1.0% by weight of "-B" and 1.0% by weight of UV absorber "Tinuvin 234" manufactured by Ciba-Geigy.

In room irradiation for 3 years, ΔE is 20
Below, almost no change in appearance was observed. Also,
The amount of metal components and the amount of TOC in the sealed water after the sealing period of 30 days were comparable to those of the single-layer tube composed of polyphenylene sulfide only.

Comparative Example 1 A single-layer pipe having the same composition as the outer layer of Example 2 and having a nominal diameter of 2
The same procedure as in Example 1 was carried out except that extrusion molding was performed with a thickness of 5 mm and a thickness of 3.6 mm.
ΔE was 20 or less, and almost no change in appearance was observed, but the amount of metal components in the sealed water on the 30th sealing period, TO
The C content was about 1.2 times that of a single-layer tube consisting of polyphenylene sulfide only.

Comparative Example 2 Polyphenylene sulfide which is the inner layer of Example 2 (“Fortron KPS W-300” manufactured by Kureha Chemical Industry Co., Ltd.)
Is a single-layer pipe with a nominal diameter of 25 mm,
The same procedure as in Example 1 was carried out except that a thickness of 3.6 mm was extruded. As a result, ΔE was 2 when the room irradiation was performed for 3 years.
It was 0 or more, and a remarkable change in appearance was observed.

[0024]

According to the structure of the present invention, the amount of metal components in a fluid such as pure water and the amount of impurities such as TOC are small. Therefore, it is suitable for use as a piping material for ultrapure water and chemical liquids, in which the fluid is required to have a particularly high purity. In addition, since there is little change in appearance, it can be used for a long time in both outdoor and indoor applications. Especially when the inner layer and the outer layer only, or when using only polyarylene sulfide as the matrix resin, since both layers have the same melting temperature, by the non-contact heating method used as a usual welding means It has the feature that it is easy to install piping.

[Brief description of drawings]

FIG. 1 is a semi-illustrated vertical cross-sectional view of a dissolution test apparatus used in Examples and Comparative Examples.

[Explanation of symbols]

 1 Short tube 2 Nitrogen gas 3 Dissolution test device 4 Make-up water 5 Electric heater

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F16L 9/12

Claims (8)

[Claims] 1. The outer layer comprises at least one of a colorant and an ultraviolet absorber and polyarylene sulfide, and the inner layer in contact with a fluid comprises 80 to 100% by weight of polyarylene sulfide and 0 to 20% by weight of another resin or rubber. A polyarylene sulfide multi-layer tube characterized by. 2. The polyarylene sulfide multi-layer pipe according to claim 1, which is used as a pipe for ultrapure water. 3. The polyarylene sulfide multi-layer pipe according to claim 1, which is used as a pipe for a chemical solution. 4. The polyarylene sulfide multilayer pipe according to claim 1, wherein the ratio of the wall thickness of the layers other than the inner layer to the wall thickness of the inner layer is 5/95 to 70/30. 5. The outer layer comprises at least one of a colorant and an ultraviolet absorber and polyarylene sulfide, and the inner layer in contact with a fluid comprises 80 to 100% by weight of polyarylene sulfide and 0 to 20% by weight of another resin or rubber. A polyarylene sulfide multi-layer pipe joint characterized by. 6. The polyarylene sulfide multi-layer pipe joint according to claim 5, which is used as a pipe for ultrapure water. 7. The polyarylene sulfide multilayer pipe joint according to claim 5, which is used as a pipe for a chemical solution. 8. The polyarylene sulfide multilayer pipe joint according to claim 5, wherein the ratio of the wall thickness of the layers other than the inner layer to the wall thickness of the inner layer is 5/95 to 70/30.