JP2006258285A - City water pipe and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a city water pipe and its manufacturing method with excellent non-contamination property to city water and high freedom of piping, capable of enhancing construction easiness at site. <P>SOLUTION: An inner surface resin layer 2 having thickness of 0.05 mm or thicker is provided on an inner peripheral surface of an inner surface rubber layer 3 of a city water pipe 1 having a reinforcement layer 4 between the inner surface rubber layer 3 and an outer surface rubber layer 5. A flowing surface of city water is made of resin and contamination (transferring of a harmful component, adhesion of odor, discoloring or the like) to city water by the inner surface rubber 3 is prevented. Flexibility of the city water pipe 1 is ensured by making the thickness to 1.0 mm or thinner. Freedom in piping is enhanced and work such as cutting and joining to a fitting is also facilitated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water supply pipe and a method for manufacturing the same, and more particularly, a water supply pipe excellent in non-contamination to tap water, having a high degree of freedom of piping, and capable of improving workability on site and a method for manufacturing the same. It is about.

  Conventionally, metal pipes such as copper pipes and cross-linked polyethylene pipes have been used in water pipes that are mainly arranged inside buildings and supply tap water around the water in kitchens, bathrooms, toilets, etc. (for example, , See Patent Document 1). These water pipes are excellent in non-polluting to tap water (transfer of harmful components, odor attachment, discoloration, etc.), but in the case of metal pipes, processing such as bending, cutting and screwing in the field is possible. Since it is difficult, it is necessary to prepare and construct a shape pipe that matches the site in advance, and there is a problem that abrupt piping (arrangement and handling) cannot be changed on site.

  In addition, the cross-linked polyethylene pipe is easier to bend than the metal pipe, but it is easy to kink and is not sufficiently flexible, and it cannot be said that the workability on site is good. In particular, when the reinforcing layer is made of a stainless steel wire or the like, there is a problem that it cannot be joined to the metal fitting.

On the other hand, the rubber hose is flexible and easy to handle, but cannot be used because it does not meet the required performance of non-polluting, and it is excellent in non-polluting against tap water and has a high degree of freedom in piping. It was necessary to have water pipes that were easy to construct.
JP 2003-342981 A

  An object of the present invention is to provide a water pipe that is excellent in non-contaminating property against tap water, has a high degree of freedom of piping, and can improve workability on site, and a method for manufacturing the same.

  In order to achieve the above object, the water pipe of the present invention is a water pipe having a reinforcing layer between an inner rubber layer and an outer rubber layer, and an inner resin layer is provided on the inner peripheral surface of the inner rubber layer, The thickness of the inner surface resin layer is 0.05 mm or more and 1.0 mm or less.

  Moreover, the manufacturing method of the water pipe of this invention is a manufacturing method of the water pipe in any one of Claims 1-4, Comprising: Concentrating the said inner surface rubber layer on the outer peripheral surface of the resin tube used as the said inner surface resin layer It is characterized by adhering and laminating with 9.0 to 17.0% phenol resin adhesive, and sequentially laminating and vulcanizing the member layers constituting the water pipe on the outer peripheral surface.

  According to the water pipe of the present invention, it is a water pipe having a reinforcing layer between the inner rubber layer and the outer rubber layer, and an inner surface resin layer having a thickness of 0.05 mm or more is provided on the inner peripheral surface of the inner rubber layer. Therefore, the surface through which tap water circulates becomes resin, and contamination (transfer of harmful components, odor attachment, discoloration, etc.) to tap water by the inner rubber layer can be prevented.

  In addition, since the thickness of the inner surface resin layer is 1.0 mm or less, the flexibility of piping is increased without impairing the flexibility of water supply piping, and processing such as cutting and joining with metal fittings becomes easy. It is possible to improve the workability.

  According to the manufacturing method for manufacturing a water pipe according to any one of claims 1 to 4 of the present invention, the inner rubber layer has a concentration of 9.0 to 17.0% on the outer peripheral surface of the resin tube to be the inner resin layer. Adhesion with phenolic resin adhesive and laminating, the adhesive component is greatly diluted and this component does not penetrate the inner resin layer and contaminate tap water, increasing non-contamination Can do. Further, since the phenol resin adhesive is excellent in adhesive force even at a low concentration, it is possible to prevent the delamination by firmly bonding the inner surface resin layer and the inner surface rubber layer.

  After that, a member layer constituting the water pipe on the outer peripheral surface, specifically, a reinforcing layer, an outer rubber layer, and a cover resin layer depending on the configuration of the pipe are laminated and vulcanized, so that a general rubber hose is manufactured. Flexible water pipes can be manufactured using the facilities as they are.

  Hereinafter, the water supply pipe and its manufacturing method of the present invention will be described based on the embodiments shown in the drawings. FIG. 1 is a perspective view illustrating a water pipe 1 according to the first embodiment with a part thereof cut.

  The water pipe 1 has a structure in which an inner surface resin layer 2, an inner surface rubber layer 3, a reinforcing layer 4, and an outer surface rubber layer 5 are coaxially laminated in order from the inner peripheral side. That is, the innermost peripheral surface through which tap water circulates is the inner surface resin layer 2, and the tap water does not contact the rubber of the inner surface rubber layer 3.

  In the manufacturing method, a resin tube to be the inner surface resin layer 2 is extruded on a mandrel, an inner surface rubber layer 3 is laminated on the outer peripheral surface of the inner surface resin layer 2, and a reinforcing layer 4 and an outer surface rubber layer 5 are sequentially laminated. It is composed of a step of vulcanizing at a temperature at which the resin tube does not melt later and pulling out the mandrel. Therefore, a general rubber hose manufacturing facility can be used as it is, and a significant addition of equipment and cost is not necessary.

  The resin used for the inner surface resin layer 2 is polypropylene (PP), polyester (PET), polyethylene (PE), polybutene (PB), polyvinyl chloride (PVC), acrylonitrile / butadiene / styrene (ABS), polyacetal (POM). Polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), polyamide (6 nylon (N6), 66 nylon (N66), 11 nylon (N11), 12 nylon (N12)), polybutylene terephthalate (PBT), etc. It can be illustrated. In particular, the above 11 nylon is preferable because it is excellent in water resistance and is easy to extrude.

  Moreover, the ultrahigh molecular weight polyethylene (which makes the inner surface resin layer 2 less likely to react to chlorine contained in tap water and can be firmly bonded to the inner rubber layer 3 of a rubber type described later without using an adhesive) UHMwPE) is preferably used.

  The thickness of the inner surface resin layer 2 is 0.05 mm or more and 1.0 mm or less. When this thickness is less than 0.05 mm, it becomes difficult to satisfy the required performance of non-contamination (transfer of harmful components, odor attachment, discoloration, etc.) to the tap water by the inner rubber layer 3 and exceeds 1.0 mm. And bending rigidity will become high and the softness | flexibility of the water pipe 1 will be impaired.

  More preferably, a thickness of 0.08 mm or more and 0.20 mm or less provides a good balance in terms of both non-contamination and bending rigidity.

  Therefore, by setting the thickness of the inner surface resin layer 2 within the above range, flexibility similar to that of the rubber hose can be ensured without contaminating tap water. As a result, even in a site where space such as the interior of a building such as a house is limited, piping can be freely made according to the needs of the site, and processing such as cutting and joining with metal fittings can be easily performed. It will be good.

  The rubber of the inner rubber layer 3 is preferably a non-plastic compounded rubber that does not contain a plasticizer. Thereby, it is possible to prevent the tap water from being contaminated by the plasticizer that easily migrates to and penetrates the inner surface resin layer 2.

  Further, the inner surface resin layer 2 and the inner surface rubber layer 3 are preferably bonded using a phenol resin-based adhesive having a strong adhesive force even when diluted to a low concentration, and the concentration is set to 9.0-17. More preferably, the content is 0.0%. Thereby, the inner surface resin layer 2 and the inner surface rubber layer 3 can be firmly bonded with a small amount of adhesive to prevent delamination. Furthermore, since the component of the adhesive is greatly diluted, it is possible to more reliably prevent tap water contamination due to permeation of the adhesive component through the inner surface resin layer 2.

  Various rubber compositions can be used for the inner rubber layer 3, but when ultrahigh molecular weight polyethylene is used for the inner resin layer 2, a styrene-butadiene copolymer rubber in consideration of the flexibility of the water pipe 1. , Butadiene rubber, butyl rubber, ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, chloroprene rubber, ethylene copolymer rubber, acrylonitrile-butadiene copolymer rubber Rubber compositions containing rubber as a main component can be used, and these rubber compositions and ultra-high molecular weight polyethylene are firmly bonded without an adhesive.

  In this embodiment, a single reinforcing layer 4 braided with fibers is provided. However, the present invention is not limited to this, and the reinforcing layer 4 can be made into a plurality of layers via an intermediate rubber layer depending on use conditions such as water pressure. Further, the fiber may be spirally wound.

  Next, FIG. 2 shows a second embodiment. This water pipe 1 is provided with a cover resin layer 6 having a thickness of 0.5 mm or more and 3.0 mm or less on the outer peripheral surface of the outer rubber layer 5 of the first embodiment, and other specifications are the same. The manufacturing method is changed in that a step of laminating the cover resin layer 6 on the outer peripheral surface of the outer rubber layer 5 is added.

  As described above, by providing the cover resin layer 6 having a thickness of 0.5 mm or more on the outermost periphery, the cover resin layer 6 prevents the outer surface rubber layer 5 from being deteriorated by ultraviolet rays even in a use environment exposed to sunlight or the like. It can prevent and improve weather resistance. Moreover, the process of joining a plurality of water pipe hoses or joining metal fittings becomes easy by joining the cover resin layers 6 of the water pipes 1 to each other.

  On the other hand, the thickness of the cover resin layer 6 is set to 3.0 mm or less to ensure flexibility without significantly increasing the bending rigidity of the water pipe 1. Examples of the resin used for the cover resin layer 6 include polyvinyl chloride and polyurethane.

  When the end of the water pipe 1 is joined to an SL metal fitting (socketless metal fitting), it is required to be easily mounted (metal fitting insertion property) and hard to come off from the joined metal fitting (detachment resistance). . In order to satisfy both of these performances, the reinforcing layer 4 is formed by braiding a reinforcing yarn 4a having a breaking elongation of 15% or less within a braid angle A of 49.4 ° or more and 52.2 ° or less, and the inner rubber layer 3 is formed. It is preferable to set the 100% modulus of the rubber composition to be 4.0 MPa or more and 10.0 MPa or less.

  In the present invention, the breaking elongation of the reinforcing yarn 4a is based on the measurement based on JIS L 1017, and the 100% modulus of the rubber composition is based on the measurement based on JIS K 6251.

  When the breaking elongation of the reinforcing yarn 4a exceeds 15%, the water pipe 1 cannot be sufficiently expanded when the internal pressure increases, and the water pipe 1 is easily pulled out. When the braid angle A of the reinforcing yarn 4a is 49.4 ° or more and 52.2 ° or less, the deformation of the water pipe 1 is moderately suppressed, and the metal fitting insertion property and the slip-out resistance can be improved. Examples of the reinforcing yarn 4a include vinylon and aramid fibers.

  Furthermore, the 100% modulus of the rubber composition constituting the inner rubber layer 3 and the outer rubber layer 5 has an influence on the slipping resistance, and the influence of the inner rubber layer 3 is particularly great. When the 100% modulus of the rubber composition constituting the inner rubber layer 3 is less than 4.0 MPa, it is not possible to obtain sufficient metal fitting resistance. On the other hand, if it exceeds 10.0 MPa, the inner rubber layer 3 is difficult to deform, and the metal fitting insertion property is deteriorated. In consideration of flexibility and resistance to breakage, the thickness is preferably in the range of 0.5 mm to 3.0 mm.

  The 100% modulus of the rubber composition constituting the outer rubber layer 5 is particularly preferably 1.5 MPa or more and 10.0 MPa or less, and the thickness is 0.5 mm to 3 mm in consideration of flexibility and slipping resistance. Preferably it is in the range of 0.0 mm. In addition, as for the thickness of the inner surface resin layer 2, 0.05 mm or more and 0.35 mm or less are especially preferable. For the outer rubber layer 5, the same rubber composition as that of the inner rubber layer 3 can be used in consideration of the flexibility of the water pipe 1.

  As described above, by specifying the specifications of the reinforcing layer 4 and the 100% modulus of the rubber composition of the inner rubber layer 3, it is easy to insert the SL metal fitting into the water pipe 1 and prevent it from coming off. it can. Thereby, construction becomes easy and the construction period can be shortened.

  9 of the water pipe of the structure of 2nd Embodiment shown in FIG. 2 which changed only the resin material of the inner surface resin layer (Examples 1-8), and the normal rubber hose (comparative example) which omitted the inner surface resin layer A predetermined amount of tap water is sealed in each of the test specimens for a predetermined time, the degree of contamination of the tap water sealed on both sides is measured, and the evaluation results are shown in Table 1. Evaluation items are detection of odor, phenols, potassium permanganate consumption, and other substances. The evaluation was performed according to the JIS S 3200-7 Water Supply Equipment-Leaching Performance Test Method.

  The inner resin layer has a thickness of 0.10 mm, the inner rubber layer has a thickness of 2.0 mm, acrylonitrile butadiene rubber, the reinforcing layer has two spirals of vinylon, the outer rubber layer has a thickness of 1.6 mm, and the cover resin layer has a thickness. 1.0 mm polyvinyl chloride was used. The inner surface resin layer and the inner surface rubber layer were bonded with a phenol resin adhesive (Ty-PlyBN manufactured by Road Far East Incorporated) diluted with methyl ethyl ketone to a concentration of 17.0%.

[Odor]
It is a sensory evaluation in which the evaluator determines the presence or absence of an unpleasant odor in tap water.

[Phenols]
Evaluation of whether the amount of phenols detected from tap water meets JIS S 3200-7 Commentary Table 3 Judgment criteria for leaching performance. The case where the value is exceeded is indicated by a cross.

[Consumption of potassium permanganate]
As an index of the amount of organic matter eluted in tap water, it is evaluated whether the potassium permanganate consumption satisfies the above JIS criteria. The case of exceeding is indicated by a cross.

[Other substances]
If the detected amount of other substances (43 types) specified in the above JIS criteria is less than or equal to this standard value for all types (when the criteria are met), ○ indicates that the detected amount is less than one Is shown.

  From these results, it was confirmed that all of Examples 1 to 8 satisfied the non-contamination performance based on the JIS standard. On the other hand, the normal rubber hose of the comparative example could not clear the non-contamination performance due to the influence of the inner rubber layer.

  Moreover, based on the water supply pipe of the structure of 2nd Embodiment shown in FIG. 2, the test body (Examples 9-17) which carried out the specification shown in Table 2 was manufactured, and metal fitting insertion property and the omission resistance of a metal fitting were measured. did. The inner diameter of the test body is 12.7 mm, the inner resin layer is made of polyamide (11 nylon) with a thickness of 0.1 mm, the reinforcing yarn is made of vinylon, and the spiral two-layer reinforcing layer, inner rubber layer, and outer rubber layer are each of the thickness. The common condition was that the 2.1 mm, 1.75 mm acrylonitrile butadiene rubber and the cover resin layer were made of PVC having a thickness of 1.0 mm. However, only in Example 17, the reinforcing yarn was made of polyester. The evaluation results are as shown in Table 2.

[Fitting insertion]
A predetermined SL metal fitting having an outer diameter of 14.5 mm was erected and fixed, and the maximum load when the SL metal fitting was inserted by moving each test body downward straight from above was measured. In the measurement, no lubricant was used in the insertion portion, and the insertion speed was 50 mm / min. Here, when the insertion force is 350 N or less, it is judged that the metal fitting insertability is good and indicated by a circle in Table 2, and when it exceeds 350 N, the metal fitting insertability is judged as a general level and indicated by a triangle. It was.

[Omission resistance]
Circulate 95 ° C. hydraulic oil inside each test specimen for 1 hour, then close one end of the specimen and apply an internal pressure of 3.0 MPa for 30 minutes. Circulate for 30 minutes. Thereafter, one end of the test specimen was closed with a predetermined SL fitting, an internal pressure was applied until the SL fitting was removed from the specimen, and the load pressure when the fitting was removed was measured to obtain a high temperature fracture strength. Here, when the high temperature fracture strength is 3.0 MPa or more, it is judged that the drop resistance is good, and in Table 2, it is indicated by a circle, and when it is less than 3.0 MPa, the drop resistance is judged as a general level. And indicated by Δ.

  From these results, by setting the specification of the reinforcing layer and the 100% modulus of the rubber composition of the inner rubber layer within a specific range (Examples 9 to 12), excellent performance that achieves both metal fitting insertion property and pull-out resistance is achieved. It was confirmed that it was obtained.

It is the perspective view which partially cut off the water supply pipe of 1st Embodiment. It is the perspective view which partially cut down the water supply piping of 2nd Embodiment.

Explanation of symbols

1 Water supply piping
2 Inner surface resin layer 3 Inner surface rubber layer 4 Reinforcement layer 4a Reinforcement thread
5 External rubber layer
6 Cover resin layer

Claims (5)

  A water pipe having a reinforcing layer between an inner rubber layer and an outer rubber layer, wherein an inner resin layer is provided on an inner peripheral surface of the inner rubber layer, and the inner resin layer has a thickness of 0.05 mm or more and 1.0 mm. The following water pipes.   The water supply pipe according to claim 1, wherein a cover resin layer is provided on an outer peripheral surface of the outer rubber layer, and the thickness of the cover resin layer is 0.5 mm or more and 3.0 mm or less.   The water pipe according to claim 1 or 2, wherein the rubber of the inner rubber layer is made of a non-plastic compound.   The reinforcing layer is formed by braiding reinforcing yarn having a breaking elongation of 15% or less in a braid angle range of 49.4 ° or more and 52.2 ° or less, and 100% modulus of the rubber composition constituting the inner rubber layer is formed. The water pipe according to any one of claims 1 to 3, wherein the pressure is 4.0 MPa or more and 10.0 MPa or less. It is a manufacturing method of the water supply pipe in any one of Claims 1-4, Comprising: The said inner surface rubber layer is a phenol resin type | system | group of density | concentration 9.0-17.0% on the outer peripheral surface of the resin tube used as the said inner surface resin layer. A method of manufacturing a water pipe, in which the layers are laminated by bonding with an adhesive, and the member layers constituting the water pipe are sequentially laminated on the outer peripheral surface and vulcanized.

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