JP2002168378A - Resin hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin tube suitable for city water piping which is excellent in sanitation performance. SOLUTION: This resin hose comprises an inner surface layer tube, and a fiber reinforcement layer comprising reinforcement fibers fabricated on an outer circumference of the inner surface layer tube. The inner surface layer has a two-layer structure comprising the innermost layer of high density polyethylene or crosslinked polyethylene, and an outer layer of thermoplastic resin or elastomer on an outer circumference of the innermost layer. The high density polyethylene or crosslinked polyethylene forming the innermost layer has a hardness of HD30-70, a density of 0.94 g/cm3 or more, and a number-averaged molar weight of 1,000,000 or more. This resin hose for piping includes no carbon or pigment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin hose, particularly a resin hose for housing or a resin hose for automobiles.
More specifically, the present invention relates to a resin hose suitable for piping for transporting cold and hot water such as domestic water piping or a water hose for automobiles.

[0002]

2. Description of the Related Art Conventionally, pipes for water supply have been mainly made of copper or stainless steel pipes or corrugated pipes whose corrugated pipe surface is used to improve flexibility. However, metal pipes have poor flexibility, the load required for bending is large, construction is difficult, and there is a problem in workability. In recent years, the outer circumference of a tube made of thermoplastic resin, elastomer, or rubber has been increased. Use a stainless steel braided hose for
Workability is improved.

[0003] The conventional resin hose has an advantage that the construction is facilitated by providing flexibility. However, since rubber or an elastomer containing a large amount of rubber is used for the inner tube, there is a drawback in that carbon and pigment foreign substances are eluted in water or hot water as a medium under a long-term use environment. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and provides a resin hose having an effect of preventing colored foreign matter from being eluted into a medium while maintaining flexibility. The purpose is to do.

[0005]

The resin hose of the present invention comprises:
An inner layer tube, a resin hose comprising a fiber reinforced layer in which reinforcing fibers are braided on the outer periphery of the inner layer tube, wherein the inner layer is an innermost layer made of high-density polyethylene or cross-linked polyethylene, and an outermost layer of the innermost layer. It has a two-layer structure consisting of an outer layer made of a thermoplastic resin or an elastomer, and a high-density polyethylene or cross-linked polyethylene forming the innermost layer has a hardness of HD30 to 70 Hs and a density of 0.93.
g / cm ³ or more, number-average molecular weight of 1,000,000 or more, and free of carbon and pigment.

[0006] The resin hose of the present invention preferably has an outer cover in which a thermoplastic resin or an elastomer is coated on the outer periphery of the fiber reinforcing layer. In the resin hose of the present invention, the outer layer of the inner surface layer tube is preferably made of a colored thermoplastic resin or elastomer.

[0007]

FIG. 1 shows the structure of a resin hose according to an embodiment of the present invention. The resin hose of FIG. 1 includes an inner surface layer tube 1 and a fiber reinforcement layer. Inner layer tube 1
Consists of two layers, an innermost layer 1a and an outer layer 1b.

[0008] The innermost layer 1a is made of high-density polyethylene or cross-linked polyethylene containing no carbon and pigment. The high-density polyethylene or the cross-linked polyethylene forming the innermost layer 1a has a hardness HD of 30 to 70 Hs, preferably 40 to 60 Hs in terms of balance between flexibility and foreign substance elution.
s, the density is 0.93 g / cm ³ or more, preferably 0.94 or more, usually 0.97 or less, and the number average molecular weight is 1,000,000 or more, preferably 1200000 or more, usually 1600000 or less.

Although the thickness of the innermost layer 1a is not limited in the present invention, it is usually 0.05 to 1 mm, especially 0.1 to 04 mm, in terms of a balance between flexibility and prevention of elution of foreign matter. Is preferred.

The outer layer 1b is made of a thermoplastic resin or an elastomer, preferably a colored thermoplastic resin or an elastomer. By using a colored thermoplastic resin or elastomer for the outer layer 1b, the thickness uniformity of the innermost layer 1a and the outer layer 1b can be visually confirmed. The thickness of the outer layer 1b is not limited in the present invention, but is preferably 0.1 to 3 mm, particularly preferably 0.5 to 2 mm in terms of balance between flexibility and prevention of elution of foreign matter.

[0011] The thermoplastic resin or elastomer can be colored, for example, by mixing a pigment. The amount of the pigment mixed with the thermoplastic resin or the elastomer is preferably 0.1 to 2% by weight. As the thermoplastic resin or the elastomer, for example, a polyolefin-based resin or a polyolefin-based elastomer can be used. Specifically, polypropylene and EPD
An olefin-based thermoplastic elastomer blended with M (ethylene propylene butadiene copolymer) can be given.

The fiber reinforcing layer can be formed by braiding reinforcing fibers on the outer periphery of the inner tube 1, for example, in a braided or spiral shape. The fiber reinforcing layer can be formed of one or more kinds of reinforcing fibers, and one layer or two or more different layers can be formed. Organic fibers such as nylon fibers and metal fibers such as stainless steel fibers can be used as the reinforcing fibers. In the resin hose shown in FIG. 1, the fiber reinforcing layer has an organic fiber reinforcing layer 2 in which nylon fibers are braided or spirally braided on the outer circumference of the inner surface layer tube 1, and a stainless steel fiber is braided or formed on the outer circumference of the organic fiber reinforcing layer 2. It is composed of a metal fiber reinforcing layer 3 braided in a spiral shape.

The resin hose shown in FIG. 1 has an outer cover 4 in which a thermoplastic resin or an elastomer is coated on the outer periphery of a fiber reinforcing layer.

[0014]

EXAMPLE 1 A resin tube having the structure shown in FIG. 1 was manufactured. The inner surface layer tube 1 has a hardness HD of 58 Hs and a density of 0.94 g.
/ Cm ³ , a number average molecular weight of 1500,000, and a colorless and transparent polyolefin resin (type: crosslinked polyethylene) containing no carbon or pigment, and forming an innermost layer 1a having a thickness of 0.3 mm. An outer layer 1b having a thickness of 0.9 mm was formed using an olefin-based thermoplastic elastomer in which polypropylene and EPDM were blended on the outer periphery of.

The organic fiber reinforcing layer 2 is formed by spirally braiding nylon fibers on the outer periphery of the inner layer tube 1, and the metal fiber reinforcing layer 3 is formed by spirally braiding stainless fibers on the outer periphery of the organic fiber reinforcing layer 2. Was formed. An outer cover 4 was formed by coating the outer periphery of the metal fiber reinforcing layer 3 with a thermoplastic resin.

A burst test was performed on the manufactured resin tube. Further, a chlorine water circulation test was performed to measure the amount of foreign substances generated, and the test water after the chlorine water circulation test was filtered to observe whether or not the filter was discolored. Furthermore, the elongation at break before and after the chlorine water circulation test was measured. Table 1 shows the results.

Comparative Examples 1 to 3 FIG. 2 shows a laminated structure of the resin hose of Comparative Example 1. The resin hose of Comparative Example 1 is an existing resin hose, in which the inner tube 1 is made of one layer of an olefin-based thermoplastic elastomer in which polypropylene and EPDM are blended, and organic fibers in which nylon fibers are spirally braided on the outer periphery thereof. A reinforcing layer 2, a metal fiber reinforcing layer 3 in which stainless fibers are braided in a spiral shape on the outer periphery thereof, and an outer cover 4 whose outer periphery is covered with a thermoplastic elastomer.

The resin hose of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the innermost layer 1a of the inner layer tube 1 was formed of a colored (skin color) polyolefin resin having a hardness HD of 60 Hs and containing a pigment. It is a resin hose made.

The resin hose of Comparative Example 3 is a resin hose manufactured in the same manner as in Example 1 except that the innermost layer 1 is formed of a colorless and transparent polyolefin resin having a hardness HD of 20 Hs.

The same test as in Example 1 was performed for each resin hose. Table 1 shows the results.

[0021]

[Table 1]

Evaluation of Test Results Comparative Example 1 having no innermost layer made of polyolefin resin
In Example 1, the amount of foreign substances generated in the chlorine water circulation test was 7 times that of Example 1. Thus, the resin hose of Example 1 has an innermost layer of a specific polyolefin resin,
It is clear that it has excellent corrosion resistance.

When the test water after the chlorine water circulation test is filtered,
In Comparative Example 1, the color of the filter after filtration changed to a dark skin color, and in Comparative Example 2 in which the innermost layer was formed of a colored polyolefin resin, the filter changed to a light flesh color. In Comparative Examples 1 and 2,
It is considered that the resin itself, which forms the inner surface causing the foreign matter, is pigment and contains a pigment and is of a flesh color. Therefore, regardless of the amount of the foreign matter, it is considered that the filter is colored.

In Comparative Example 3, in which the innermost layer was formed of a colorless polyolefin resin having a hardness HD of 20 Hs and containing no pigment, the filter was colorless after filtering the test water after the test, but remained in the hose. The amount of foreign matter was three times that of Example 1. This is presumably because, even if the polyolefin resin is the same in material, the material having a low hardness is deteriorated by chlorine.

The resin hose of Example 1 showed a small amount of foreign matter in the chlorine water circulation test, and the filter after filtering the test water after the test did not show any discoloration.

[0026]

According to the present invention, it is possible to provide a resin hose which is more hygienic than a conventional product and is particularly useful as a water supply pipe or the like.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a laminated structure of a resin hose according to an embodiment (Example 1) of the present invention.

FIG. 2 is a schematic diagram showing a laminated structure of a resin hose of Comparative Example 1.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 inner surface layer tube 1a innermost layer 1b outer layer 2 organic fiber reinforcing layer 3 metal fiber reinforcing layer 4 outer cover

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 3H111 AA02 BA15 BA25 BA29 BA34 CA53 CB06 CC03 CC18 CC19 DA26 DB03 4F100 AB04C AK01B AK01D AK04A AK05A AK07B AK48C AK75B AL05B AL09B AL09D BA03 BA04 BA07 BA10A10 GB10 BA10 BA10 BA10 JA07A JA13A JB01 JB16B JB16D JK01 JK08 JK12A JL10B YY00A

Claims (3)

[Claims] 1. A resin hose comprising: an inner layer tube; and a fiber reinforced layer in which reinforcing fibers are braided on the outer periphery of the inner layer tube, wherein the inner layer is an innermost layer made of high-density polyethylene or crosslinked polyethylene; 2 consisting of an outer layer of a thermoplastic resin or an elastomer on the outer circumference of the innermost layer
The high-density polyethylene or the crosslinked polyethylene having a layer structure and forming the innermost layer has a hardness of HD30 to 70, a density of 0.93 g / cm ³ or more, and a number average molecular weight of 1,000,000.
A resin hose for piping characterized in that it does not contain carbon and pigment. 2. The resin hose according to claim 1, further comprising an outer surface cover coated with a thermoplastic resin or an elastomer on an outer periphery of the fiber reinforcing layer. 3. The resin hose according to claim 1, wherein the outer layer of the inner layer tube is made of a colored thermoplastic resin or elastomer.