JP2006144875A - Hose for water supply/hot water supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hose having such an inner tube structure that can prevent the hose from being deteriorated by chlorine present in water and hot water and also prevent it from odorizing and being colored. <P>SOLUTION: This hose for water supply/hot water supply comprises an inner layer tube 1 and a reinforcement layer 2. The inner layer tube comprises an inner layer formed of a copolymer fluoroplastic having tetrafluoroethylene, vinylidene fluoride, and hexa fluoropropyrene and an outer layer 1B formed of a polyorefine elastomer or a styrene elastomer. An intermediate resin layer 1C formed by mixing an ethylene copolymerplastic containing glycizil metacrylate in polyethylene or polypropyrene is disposed between the inner layer and the outer layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hose used for piping for water supply and hot water supply.

  Traditionally, hoses used for storage tanks for kitchens, washstands and toilets, and other pipes for water supply and hot water supply are mainly made of rubber or thermoplastic elastomer, and the outer periphery is made of stainless steel wire, nylon or polyester. A flexible hose that is braided and reinforced with a fiber such as a fiber is used, and is used as a hose-type flexible expansion joint in which a fitting is fastened and fastened.

  However, hypochlorous acid is usually injected into tap water for sterilization, and it is necessary to maintain a sterilizing effect that the chlorine concentration is 0.1 ppm or more. In particular, when used for water supply equipment, it is required that the tap water having the above-described chlorine concentration is retained in the equipment, and the residual amount of chlorine after 24 hours is maintained at 50% or more of the initial value. It is also necessary that the stagnant water does not smell or color.

  However, when the hose having the above structure is used for water supply or hot water supply, there is a problem that the inner surface layer is easily deteriorated due to the influence of chlorine during long-term use. For this reason, a hose having a two-layer structure in which polybutene or cross-linked polyethylene is arranged in the inner layer of the inner surface layer as an inner tube structure has been used, and the durability with chlorine water has been remarkably improved. It has been found that when a test for circulating hot water in the hose is performed, it is eventually deteriorated by the influence of chlorine.

  In order to overcome the above problems, it has been considered to use a fluororesin for the inner surface layer. Such fluororesins have been conventionally used as beverage tubes because they exhibit excellent properties such as chemical resistance, non-adhesiveness, gas barrier properties, non-eluting properties, and food hygiene. The fluororesin single layer has a disadvantage that the cost is high and the resin itself is hard, so that the flexibility of the hose is poor.

  Therefore, it was considered to provide a fluorine-based resin layer that is more excellent in chlorine resistance than polybutene or cross-linked polyethylene limited to the inner layer of the inner surface layer, but it does not easily adhere to other resins such as thermoplastic elastomers. When the hose is buckled, the inner layer and the outer layer are peeled off, and only the inner layer is bent and crushed. Here, the reason why the fluororesin layer is used only for the inner layer and the other resin is laminated on the outer layer is that the fluororesin is expensive, so that the amount used is reduced (Patent Document 1).

JP 2003-343773 A

  If an attempt is made to use a relatively inexpensive resin for the outer layer as it is, the adhesive force in the coextrusion molding becomes weak, and the resin peels from the inner layer of the fluororesin layer. For this reason, a new adhesive layer needs to be interposed between the inner layer of the fluororesin layer and the outer layer of a relatively inexpensive resin or the like, which does not lead to cost reduction. In order to ensure this adhesion, there is a technique in which a polyurethane resin or a polyurethane-based elastomer is interposed as an outer layer resin. However, since these are relatively expensive, there is a problem in further cost reduction (Patent Document 2). ).

JP-A-8-142151

  The present invention is intended to solve these drawbacks, and provides a hose having an inner tube structure that prevents deterioration caused by chlorine present in water and hot water, and prevents odors and colors. It is intended to do.

  The structure of the present invention is a water supply / hot water supply hose comprising at least an inner surface layer tube and a reinforcing layer surrounding the outer surface tube, and the inner surface layer of the inner layer layer is made of tetrafluoroethylene and vinylidene fluoride. Copolymer fluorine resin composed of hexafluoropropylene, outer layer is made of polyolefin elastomer or styrene elastomer, and ethylene copolymer resin containing glycidyl methacrylate is blended with polyethylene or polypropylene between the inner layer and outer layer This is a water supply / hot water supply hose having an inner pipe structure in which the intermediate resin layer is arranged.

  The melting point of the copolymerized fluororesin is 100 to 200 ° C., and the inner layer has a thickness of 0.01 to 0.50 mm. The inner tube structure of the inner layer, the intermediate layer, and the outer layer is coextruded. This is a water supply / hot water supply hose in which an inner surface tube is formed.

  By adopting a specific copolymer fluororesin as the inner layer of the inner surface layer, and further specifying the intermediate layer accordingly, the inner layer of the fluororesin and the outer layer of the elastomer are firmly bonded, and the hose is bent. The inner layer is not peeled off, is flexible, prevents deterioration due to chlorine contained in tap water, and makes it possible to prolong the life of the hose significantly.

  If only a hose that is less deteriorated with respect to chlorine water is provided, the inner surface layer tube may be composed of only a fluororesin. However, since a normal fluororesin is hard, the necessary flexibility as a hose cannot be obtained. Therefore, a two-layer inner layer tube in which a fluorine resin is used for the inner layer and a thermoplastic elastomer is used for the outer layer as the inner layer can be considered, but the fluorine resin and the thermoplastic elastomer are firmly bonded. However, if these are simply coextruded, the inner layer peels off when the hose is bent, and the inner layer tube is bent.

  The present invention has been improved on the basis of such knowledge, and as described above, the inner surface layer of the inner tube structure is an inner layer made of a specific fluorine-based resin, and the adhesion between the inner layer and the outer layer is improved. The hose obtained by this has a characteristic hose that retains flexibility and does not cause peeling in the inner surface layer even when bent. It is a thing.

(Inner layer that forms the inner layer)
The inner layer is a copolymerized fluororesin composed of tetrafluoroethylene, vinylidene fluoride, and hexafluoropropylene. The copolymerized fluororesin layer has chemical resistance, non-adhesiveness, gas barrier properties, non-eluting properties, food Since it exhibits excellent properties such as hygiene, it is particularly suitable for beverages, automobile fuels and the like. The thickness is 0.01 to 0.50 mm, preferably 0.03 to 0.20 mm.

  The melting point of the copolymerized fluororesin layer is preferably 100 to 200 ° C. This is because by using such a low melting point copolymerized fluororesin layer, processability is improved and multilayering with a low melting point material such as polyethylene can be achieved.

  What constitutes the copolymerized fluororesin layer is a three-component system, and one of the fluororesins having tetrafluoroethylene as a component is chemical resistance, non-adhesiveness, gas barrier property, non-elution property, It has excellent properties such as food hygiene.

  The second component, vinylidene fluoride, is suitable for use in beverage tubes, since it has no food hygiene problems, has a low coefficient of friction, and has little odor adsorption. However, since a tube using vinylidene fluoride has high hardness and low tensile elongation at break, it is difficult to connect to a bamboo shoot-like pipe joint or the like, and vinylidene fluoride may be whitened after being inserted. And when a tube is bent, a bending part may be whitened.

  Therefore, the third component hexafluoropropylene is used to reduce the hardness and increase the flexibility. When such a component is added, the tensile strength at break increases and the flexural modulus decreases. Further, since the fluorine content in the copolymerized fluororesin layer is increased, surface hydrophobicity, bacteria resistance, contamination resistance, acid resistance, and alkali resistance are improved.

(Outer layer that forms the inner layer)
The outer layer is a polyolefin-based elastomer or a styrene-based elastomer, and the thickness of the outer-layer resin is 0.5 to 5.0 mm, preferably 1.0 to 2.0 mm.

(Intermediate layer forming the inner layer)
This intermediate layer is intended for adhesion between the inner layer and the outer layer described above, and is a layer in which an ethylene copolymer resin containing glycidyl methacrylate is blended with polyethylene or polypropylene, and in some cases, ethylene vinyl acetate, It may be blended with an olefin elastomer having the above-mentioned compound as a main component, polystyrene, or polyester elastomer. The intermediate resin layer is desirably as thin as possible.

  For the intermediate layer for bonding, polyethylene or polypropylene alone cannot be bonded to the fluorine-based resin, but it is bonded to the fluorine-based resin by mixing an ethylene copolymer resin containing glycidyl methacrylate with this, In addition, the present inventors have found that adhesion with an outer layer of a polyolefin-based elastomer can also be obtained, and the present invention has been achieved.

  Here, in particular, glycidyl methacrylate is used for adhesion to the copolymerized fluororesin layer. In addition, ethylene copolymer resin containing glycidyl methacrylate is used because polyethylene has a basic polymer structure, and by adding glycidyl methacrylate to this, it can be bonded to various other resins. This is to obtain a polymer. In addition, the blending ratio of glycidyl methacrylate to ethylene copolymer resin is preferably 2 to 30% by weight, and if it is less than that, the required adhesive strength cannot be obtained, and if it is more than that, improvement in adhesive strength cannot be expected, optimal 8 to 12% by weight provides the strongest adhesive strength. In contrast, the ethylene copolymer resin alone cannot be bonded to the thermoplastic elastomer.

  Then, by using an adhesive glycidyl methacrylate-containing ethylene copolymer resin, it is possible to use a resin that does not adhere to the copolymerized fluororesin layer by itself. In other words, these resin layers can be bonded to the copolymerized fluororesin layer by blending with polyethylene, polypropylene, or ethylene vinyl acetate, or olefin-based elastomers, polystyrene, or polyester-based elastomers based on these. It has become.

  As a result, it is possible to use these inexpensive resins with respect to the polyurethane resin or the like without separately interposing an adhesive layer, and the cost can be reduced as compared with the case of using the polyurethane resin or the like.

  Particularly preferably, the inner layer tube is formed by co-extrusion of the inner tube structure of the inner layer, the intermediate layer, and the outer layer, and has a melting point of 100 to 200 ° C. as described above. When is used, a strong adhesive force can be obtained by co-extrusion of the three layers.

  As a reinforcing layer, a soft or hard stainless fine wire having a thickness of φ 0.2 to 0.4 mm, a braided layer using a synthetic fiber or a spiral wound layer, or a braided layer of a stainless fine wire on a synthetic fiber It is good to be.

  It is better if an outer surface layer for protecting the reinforcing layer, for example, a thermoplastic resin layer is provided on the reinforcing layer.

Hereinafter, the water supply / hot water supply hose of the present invention will be described with reference to the drawings.
FIG. 1 is a cutaway perspective view showing Embodiment 1 of the hose of the present invention. As an inner tube structure, 1 is an inner surface layer tube, and the inner layer 1A is made of tetrafluoroethylene, vinylidene fluoride, hexa It is a copolymerized fluorine resin (thickness 0.1 mm) made of fluoropropylene, and the outer layer 1B is a polyolefin elastomer (thickness 1.5 mm). Further, an intermediate resin layer 1C in which an ethylene copolymer resin containing glycidyl methacrylate is blended with polyethylene by 10% is interposed between the inner layer 1A and the outer layer 1B. In each inner tube structure, an inner layer tube was formed by coextrusion molding. The copolymerized fluororesin used here has a melting point range of 110 to 130 ° C.

  Around the surface of the inner tube structure (outer layer 1B), a polyester fiber (1100 denier, number of twists of 3 times / 10 cm) wound as a first reinforcing layer 2A spirally at a stationary angle in the left-right direction is wound. Further, a presser thread (polyester fiber) 2a is also roughly wound around the surface in a spiral shape. Then, a metal hard wire (φ0.29) was knitted as the second reinforcing layer 2B thereon, and a styrene-based thermoplastic resin layer was formed as the jacket 3 for protecting the metal hard wire 2B.

  The hose described above was an excellent hose that could be bent easily even with a relatively small radius, did not cause kinking, and showed no separation between the layers. Therefore, it is possible to perform construction even in a narrow piping space, and the ease of construction and improvement in durability are ensured.

  FIG. 2 shows a polyester fiber (1100 denier) braided as a reinforcing layer 2 on the surface of the inner tube structure (outer layer 1B) of Example 1 of the hose of the present invention. A resin layer is formed. It should be noted that the adhesive layers 4 and 5 are preferably provided inside and outside the reinforcing layer 2 respectively, but are not particularly mentioned here.

  Even in this example, the inner tube structure was formed by coextrusion, and no delamination was observed with respect to bending or the like.

Hereinafter, the test was simplified and the adhesion evaluation on the sheet was performed.
That is, a fluororesin (THV) and a thermoplastic elastomer (santoprene) are laminated with a sheet in which PE is blended with a glycidyl methacrylate-containing ethylene copolymer resin, and this is heated and bonded to 250 ° C. under pressure. Then, the peeling test of both was performed.

  The test results are shown in Table 1. In addition, the case where there was no intermediate layer as Comparative Example 1, the case where the intermediate layer was PE as Comparative Example 2, and the case where the intermediate layer was a glycidyl methacrylate-containing ethylene copolymer resin as Comparative Example 3 were tested. In Comparative Example 1, delamination frequently occurred although flexibility was good. The same was true for Comparative Examples 2 and 3.

  Table 1 shows test results when the content of the ethylene copolymer resin containing glycidyl methacrylate with respect to PE is changed to be an intermediate layer. As a result, the maximum value was obtained when the content was 10%. It was found that the content was sufficiently used up to about 30%. Incidentally, when the content is 0%, it is Comparative Example 2, and when it is 100%, it is Comparative Example 3. All were flexible.

Contents of the inner tube structure in Example 1 and Comparative Examples 1 to 3 above, and the inner tube structure in Examples 2 to 3 and Reference Examples 1 to 3, chlorine resistance, flexibility, delamination of inner surface layer and outer surface layer Is shown in Table 2.
The outline of the test method is as follows.
* Chlorine-resistant water: Determine the degree of discoloration by immersing in 500 ppm chlorine water at 80 ° C * Flexibility: The repulsive force of the hose when processed into a hose with an inner diameter of 9φ and bent to a bending radius of 60 mm Comparison * Delamination: Cut the co-extruded inner tube tube into a sheet, and conduct a peel test on the inner and outer layers

Among the characteristics of the inner tube structure, in terms of chlorine water resistance, it is understood that in Reference Examples 1 and 2, discoloration occurs at a relatively early stage, which leads to deterioration and cannot be used.
In terms of flexibility, Reference Example 3 has excellent chlorine water resistance but is not flexible and cannot be used in practice.

  About delamination, about Comparative Examples 1-3, peeling generate | occur | produces in the early stage, and it cannot use for use.

  On the other hand, in the inner pipe structures of Examples 1 to 3 of the present invention, it has a balanced performance in terms of chlorine water resistance, flexibility, and delamination, and can be sufficiently used for actual use. It turns out that you can.

  The present invention is as described above, and the inner tube structure of the hose is firmly bonded to the inner layer of the fluororesin and the outer layer of the elastomer, and the inner layer is not peeled even if the hose is bent, and is flexible. In addition, it has been described as a hose for water supply and hot water supply that has prevented the deterioration due to chlorine contained in tap water and has made the hose life much longer, but technically limited to this. It can be applied to the hoses of all fields.

FIG. 1 is a cutaway perspective view of a first example of the present invention. FIG. 2 is a cutaway perspective view of a second example of the present invention.

Explanation of symbols

1. Internal tube,
1A ... Copolymerization fluorine resin layer,
1B ... outer layer,
1C Intermediate resin layer
2, 2A, 2B ... reinforcement layer,
3. The outer jacket.

Claims (4)

  A water supply / hot water supply hose comprising at least an inner surface tube and a reinforcing layer surrounding the outer layer tube, and the inner layer tube is composed of tetrafluoroethylene, vinylidene fluoride and hexafluoropropylene. It is a copolymerized fluororesin, the outer layer is made of a polyolefin elastomer or styrene elastomer, and an intermediate resin layer in which an ethylene copolymer resin containing glycidyl methacrylate is blended with polyethylene or polypropylene is disposed between the inner layer and the outer layer. A water supply / hot water supply hose characterized by having an inner pipe structure.   The water / hot water supply hose according to claim 1, wherein the copolymerization fluorine-based resin has a melting point of 100 to 200 ° C.   The water / hot water supply hose according to claim 1 or 2, wherein the inner layer has a thickness of 0.01 to 0.50 mm.   The water / hot water supply hose according to any one of claims 1 to 3, wherein an inner layer tube is formed by co-extrusion of an inner layer, an intermediate layer, and an outer layer of the inner tube structure.

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