JP2007190769A - Hose for supplying water and hot water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hose for supplying water and hot water which is improved in flexibility and excellent in chlorine water resistance. <P>SOLUTION: The hose for supplying water and hot water is composed of at least an inner surface layer tube 1 and a reinforcing layer 4 surrounding its outer layer. The inner layer 2 of the inner surface layer tube 1 is made of a polyester thermoplastic elastomer, and the outer layer 3 is made of a vulcanized rubber, a thermoplastic elastomer, or a thermoplastic resin having a hardness (durometer type A) of 90° or below. The thickness of the inner layer 2 is 0.05-0.40 mm. The vicat softening point of the polyester thermoplastic elastomer is preferably at least 100°C. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a water supply and hot water supply hose, and more particularly, to a water supply and hot water supply hose that is flexible and has excellent chlorine water resistance and is suitable for water supply pipes and water supply and hot water supply pipes.

  Tap water is usually infused with hypochlorous acid for sterilization, and a chlorine concentration of 0.1 ppm or more is required to maintain the sterilization effect. Moreover, in the 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.

  Conventionally, hoses with a structure in which ethylene / propylene / diene copolymer (EPDM) rubber is used as the inner surface layer and a reinforcing layer is arranged on the outer periphery have been widely used as hoses used for water supply and hot water piping in such water supply equipment. It has been. However, when a hose having such a structure is used as a hot water supply pipe, chlorine in tap water is consumed by the rubber or organic matter of the EPDM rubber inner surface layer, and it is difficult to satisfy a predetermined condition regarding the chlorine concentration in tap water. The current situation was to become. In addition, when used for a long time, there is a problem that the EPDM rubber on the inner surface of the hose is eroded by the influence of chlorine in tap water and is easily broken.

  For this reason, a metal bellows tube is generally used only for hot water supply piping, and it has been proposed to use a polybutene resin pipe in part. However, since these pipes are hard and lack flexibility, they have the disadvantage of being inferior in handleability and construction workability.

Therefore, the conventional hose for solving the problems related to the conventional water supply and hot water supply hoses, maintaining the concentration of residual chlorine in the water and hot water, and preventing the smell and color, and the conventional bellows tube The present applicant has previously proposed a hose that has solved the difficulty in handling pipes made of polybutene or the like (Patent Document 1). Such a hose is a hose comprising at least an inner surface layer tube and a reinforcing layer surrounding the outer layer, and the inner surface layer is made of a thermoplastic elastomer or vulcanized rubber whose inner layer is a fluororesin layer and whose outer layer is flexible. Become.
JP-A-9-126364 (Claims etc.)

  The hose for hot water supply and hot water described in Patent Document 1 has almost solved the problems up to that point, but today it is more flexible and excellent in chlorine water resistance, and it is an inner surface tube that replaces the fluororesin tube. Is required.

  Accordingly, an object of the present invention is to provide a water and hot water supply hose that is more flexible than ever and excellent in chlorine water resistance.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the above object can be achieved by using a polyester-based thermoplastic elastomer for the innermost layer of the hose under predetermined conditions, and the present invention has been completed. It came to do.

  That is, the water supply hot water supply hose of the present invention is a hose comprising at least an inner surface layer tube and a reinforcing layer surrounding the outer layer, wherein the inner layer of the inner surface layer tube is a polyester-based thermoplastic elastomer, and the outer layer is a durometer type A. It is a vulcanized rubber having a hardness of 90 degrees or less, a thermoplastic elastomer or a thermoplastic resin, and the inner layer has a thickness of 0.05 to 0.40 mm.

  In the water and hot water supply hose of the present invention, the polyester-based thermoplastic elastomer preferably has a Vicat softening point of 100 ° C. or more, and when the outer layer is a vulcanized rubber having a durometer type A hardness of 90 degrees or less, The polyester-based thermoplastic elastomer preferably has a Vicat softening point of 150 ° C or higher, more preferably 170 ° C or higher. The reinforcing layer is preferably a layer formed by braiding soft or hard stainless fine wires, and the fine wires preferably have a thickness of 0.2 to 0.4 mmφ. The reinforcing layer is also preferably a synthetic fiber braided layer or a spiral wound layer. Furthermore, the outer surface layer which protects this reinforcement layer can be provided in the outer side of the said reinforcement layer.

  Here, the Vicat softening temperature is measured in accordance with JIS K7206-1982 at a load of 1 kg.

  ADVANTAGE OF THE INVENTION According to this invention, the hose which is flexible and excellent in chlorine water resistance can be provided by using the polyester-type thermoplastic elastomer excellent in chemical resistance and water resistance, and prescribing | regulating the thickness. In addition, when applying a polyester-based thermoplastic elastomer having a Vicat softening point of 150 ° C. or higher for the inner layer of the inner layer to be applied to the hose, as an additional layer of the unvulcanized rubber as the outer layer of the inner layer tube It becomes possible to vulcanize after lamination, and since the Vicat softening point is higher than that of the polyolefin resin applied to the conventional water and hot water supply hoses, it is possible to withstand even higher temperatures.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a partially cutaway perspective view of a water and hot water supply hose according to a preferred embodiment of the present invention. In the figure, the inner surface layer tube 1 is composed of a polyester-based thermoplastic elastomer layer as an inner layer 2 that is in direct contact with hot water and an outer layer 3 formed on the outer layer. The outer layer 3 has a durometer type A hardness of 90. A vulcanized rubber, a thermoplastic elastomer or a thermoplastic resin of less than or equal to the degree. Note that an adhesive layer may be provided between the inner layer 2 and the outer layer 3 as necessary. In addition, the hose of the illustrated example has a reinforcing layer 4 that surrounds the outer layer 3 and braids it.

  In the present invention, examples of the polyester-based thermoplastic elastomer of the inner layer 2 of the inner layer tube 1 include a block copolymer of a plurality of polyesters, a transesterification product made from an ester compound / polyol / polyalkyl glycol, and a polycondensation product. Examples thereof include a reaction product, a block copolymer of polyethylene and polyether, and a polymer alloy of polyester and a rubber component.

  In the present invention, it is important that the thickness of the inner layer 2 is 0.05 to 0.40 mm, preferably 0.1 to 0.3 mm. If the thickness is less than 0.05 mm, the amount of residual chlorine in tap water is greatly reduced. On the other hand, if the thickness exceeds 0.40 mm, the hose becomes hard and difficult to bend, resulting in poor handling.

  Further, the Vicat softening point of the polyester-based thermoplastic elastomer of the inner layer 2 is not particularly limited in water supply applications, but when used in hot water supply applications, it is desirable that the Vicat softening point is at least 100 ° C., preferably 105 ° C. or more. It is. The higher the Vicat softening point at this time, the higher the resistance in a high temperature environment than the polyolefin resin.

  The thermoplastic elastomer as the outer layer 3 of the inner layer tube 1 having a durometer type A hardness of 90 degrees or less includes polystyrene, polyolefin, polyurethane, polyester, polyamide, ethylene-vinyl acetate, chlorination. A thermoplastic elastomer having flexibility such as polyethylene, fluorine, and polyvinyl chloride, and in some cases, polyvinyl chloride and polyethylene are used.

  In addition, a blend of two or more thermoplastic elastomers, or a blend of a thermoplastic resin such as polyester, for example, polyethylene terephthalate (PET), and a thermoplastic elastomer may be used as the material. However, even in this case, the outer layer 3 must have a Shore A hardness of 90 degrees or less, preferably 85 degrees or less. When the Shore A hardness exceeds 90 degrees, sufficient flexibility as a hose cannot be obtained.

  Also, when a thermoplastic elastomer is used for the outer layer 3 of the inner layer tube 1, it is preferable to set a Vicat softening point equal to or higher than that of the polyester thermoplastic elastomer of the inner layer 2. In this case, two layers of the thermoplastic elastomer forming the inner layer 2 and the outer layer 3 can be simultaneously extruded to form a two-layer inner layer tube 1. Further, if necessary, the inner layer 2 and the outer layer 3 are extruded separately, and an adhesive is applied after the inner layer 2 is extruded, or by simultaneously extruding the inner layer 2 and the outer layer 3 via an adhesive layer, An adhesive layer may be provided between the inner layer 2 and the outer layer 3.

  Further, when vulcanized rubber is used as the outer layer 3 in the present invention, as such vulcanized rubber, natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), ethylene / propylene / Examples include diene copolymer (EPDM), acrylic rubber, butyl rubber (IIR), and nitrile rubber (NBR) rubber.

  When the inner layer tube 1 is manufactured using the vulcanized rubber as the outer layer 3, the polyester thermoplastic elastomer which is the resin of the inner layer 2 is extruded, then the unvulcanized rubber layer as the outer layer 3 is extruded, and then added. Sulfur will be performed. At this time, in order for the polyester-based thermoplastic elastomer of the inner layer 2 to have sufficient resistance to the vulcanization temperature, the vulcanization temperature is around 150 ° C., so the polyester-based heat of the inner layer 2 at this temperature The state change of the plastic resin elastomer is important. When a polyester-based thermoplastic elastomer having a Vicat softening point lower than 150 ° C. is used, the resin of the inner layer 2 is softened during vulcanization, and the resin becomes uneven, so that the function of the original inner layer 2 cannot be exhibited. Therefore, it is preferable to use a polyester-based thermoplastic elastomer having a Vicat softening point of 150 ° C. or higher, more preferably 170 ° C. or higher. However, this is not the case when a thermoplastic elastomer is used for the outer layer 3 of the inner layer tube 1 because it is not exposed to high temperatures.

  Moreover, in this invention, it has the reinforcement layer 4 which enclosed the outer layer 3 and knit it up. The reinforcing layer 4 is made of, for example, synthetic resin fibers such as vinylon, polyester, nylon, and aramid fibers, which are braided to form a reinforcing layer, or wound in a spiral shape to form a reinforcing layer. As another example of the reinforcing layer, for example, in a hose used when the pressure is high, it is possible to braid and reinforce a soft or hard stainless fine wire or brass fine wire using a knitting machine or the like. is there. Such a stainless fine wire is preferably 0.2 to 0.4 mmφ in thickness from the viewpoint of flexibility and reinforcement of the hose. The reinforcing layer 4 may remain exposed as it is, but it is needless to say that an outer surface layer (not shown) may be further formed on the reinforcing layer 4.

  By forming this outer surface layer, it is possible to use it outdoors by using a weather-resistant material such as EPDM rubber or acrylic rubber. In addition, it is possible to provide functions such as making it difficult for dust and dirt to adhere to the back surface of the hose and easily cleaning the surface. In this case, as applicable materials, thermoplastic resins and thermoplastic elastomers can be used in addition to the various rubber materials described above.

  Moreover, when design harmony with the surrounding instrument to be used is required, for example, a colorful hose can be provided. It is also possible to provide a hose capable of fusing the hoses together. As an outer surface layer in this case, for example, a vinyl chloride resin, a thermoplastic elastomer similar to the outer surface layer as described above, or a composite outer layer in which a thermoplastic resin is further coated on a rubber outer layer can be used.

Hereinafter, the present invention will be described based on examples.
(Examples 1-3, Comparative Examples 1-5)
As a material for forming the inner layer 2 of the inner surface tube 1 of the hose of the type shown in FIG. 1, a polyester-based thermoplastic elastomer (manufactured by Toray DuPont, “Hytrel 4777”, Vicat softening temperature: 166 ° C.) was used. A two-layer inner layer tube was obtained by two-layer coextrusion molding using a polyolefin-based thermoplastic elastomer (AES Japan, “Santoprene 8201-70”) as the outer layer 3. Six soft stainless fine wires having a diameter of 0.22 mmφ were combined on one bobbin on the outer periphery of the tube, and the reinforcing layer 4 was knitted using a knitting machine for 24 bobbins.

(Examples 4-6, Comparative Examples 6-9)
A polyester thermoplastic elastomer (manufactured by Toray DuPont, “Hytrel 5577”, Vicat softening temperature: 192 ° C.) was used as a material for forming the inner layer 2 of the inner surface layer tube 1. The polyester-based thermoplastic elastomer was extruded onto the mandrel, and then the polyester-based thermoplastic elastomer was subjected to corona discharge treatment to apply an adhesive. An unvulcanized product of EPDM rubber is extruded to the outer layer 3, and a polyester fiber is wound spirally and alternately on two layers to form a reinforcing layer 4. Further, an unvulcanized EPDM rubber is formed as an outer surface layer. The target hose was produced by extruding a product and coating a resin mold on it, followed by hot air vulcanization at 150 ° C. for 60 minutes.

The following flexibility test and residual chlorine test were performed on the hose manufactured as described above.
(Flexibility test)
A bending force test was performed to compare the flexibility of the hose, that is, the handleability and workability. In this bending force test, the force when the hose was bent to a radius of 100 mm and 50 mm was measured with a spring balance.
(Residual chlorine test)
The residual chlorine test was measured using a residual chlorine measuring device (manufactured by Shibata Kagaku Kikai Kogyo Co., Ltd.) using orthotolidine. The outline of this measuring method is that water whose chlorine concentration is adjusted to 1 ppm with sodium hypochlorite is retained in the hose, and the chlorine concentration after 24 hours is measured by the above method and the weight loss is shown as a ratio. is there.
The obtained measurement results are shown in Tables 1 to 4 below.

  The hose that is actually used as the hot water supply needs to be bent easily to a bending radius of about 50 mm, and the bending force is preferably 1000 g or less. As can be seen from the table, when the thickness of the polyester-based thermoplastic elastomer layer exceeds 0.4 mm, it becomes hard and difficult to bend, and it is understood that the handleability is deteriorated. On the other hand, the reduction of residual chlorine is greatly influenced by the thickness of the inner layer, that is, the polyester elastomer layer, and it is understood that this layer needs to have a thickness of at least 0.05 mm.

FIG. 2 is a partially cutaway side view when the fitting 10 is attached using the hose shown in the first embodiment. The nipple 11 is inserted into the diameter of the hose and the sleeve 12 is crimped (13). The metal fitting 10 is attached. When the pressure resistance and repeated pressure test of the hose to which the fitting 10 was attached were performed, the pressure resistance until breakage was 11.8 MPa (120 kgf / cm ² ), and 0 to 1.72 MPa (17.5 kgf / cm). ^The result of repeating the pressure test of ² ) at intervals of about 20 seconds and performing a pressure test was confirmed to be a hose that is sufficiently practical without any abnormality even after 100,000 times. As a method for connecting the hose, a simple connection method such as band fastening can be applied in addition to the method of using the fitting as described above.

It is a partially cutaway perspective view of a water / hot water hose according to a preferred embodiment of the present invention. It is a partial cutaway side view of the hose of Example 1 which attached the fitting metal fitting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner surface layer tube 2 Inner layer 3 Outer layer 4 Reinforcement layer 10 Joint metal fitting 11 Nipple 12 Sleeve 13 Clamping part

Claims (8)

  A hose comprising at least an inner layer tube and a reinforcing layer surrounding the outer layer, wherein the inner layer of the inner layer tube is a polyester-based thermoplastic elastomer, and the outer layer is a vulcanized rubber having a durometer type A hardness of 90 degrees or less, heat A hose for water supply and hot water, which is a plastic elastomer or a thermoplastic resin, and the inner layer has a thickness of 0.05 to 0.40 mm.   The hose for hot and cold water supply according to claim 1, wherein the polyester-based thermoplastic elastomer has a Vicat softening point of 100 ° C. or higher.   The water supply and hot water supply hose according to claim 1, wherein when the outer layer is a vulcanized rubber having a durometer type A hardness of 90 degrees or less, a Vicat softening point of the polyester-based thermoplastic elastomer is 150 ° C or higher.   The hose for hot and cold water supply according to claim 3, wherein the polyester-based thermoplastic elastomer has a Vicat softening point of 170 ° C. or higher.   The water supply hot water supply hose according to any one of claims 1 to 4, wherein the reinforcing layer is a layer formed by braiding soft or hard stainless fine wires.   The water supply and hot water supply hose according to claim 5, wherein the thin wire has a thickness of 0.2 to 0.4 mmφ.   The hose for hot and cold water supply according to any one of claims 1 to 4, wherein the reinforcing layer is a braided layer or a spiral wound layer of synthetic fibers.   The water supply and hot water supply hose according to any one of claims 1 to 7, wherein an outer surface layer for protecting the reinforcement layer is provided outside the reinforcement layer.

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