JP2014169714A - Ultrahigh pressure resin hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrahigh resin hose using resin material which hardly causes fluid leakage due to inner pipe cracking on a caulking part of a mouthpiece and facilitates molding of an inner pipe, and to provide a method of manufacturing the ultra high resin hose.SOLUTION: An ultrahigh resin hose includes an inner pipe, a reinforcement layer made of metal wire and a jacket layer. The ultrahigh resin hose is characterized in that the inner pipe has a double layer structure of which the inner layer is made of fluorocarbon resin and the outer layer is made of polyamide resin, and a delamination strength (in accordance with JIS K 6330-6:2010) of the inner layer and the outer layer is 20 N/cm or more. Further, a manufacturing method of the ultrahigh resin hose is characterized in that the inner pipe composed of the inner layer and the outer layer is molded according to co-extrusion molding.

Description

  The present invention relates to an ultra-high pressure resin hose, and more particularly to an ultra-high pressure resin hose that hardly causes fluid leakage at a caulking portion of a mouthpiece.

  Ultra-high pressure resin hoses are used for transportation of liquids, gases, powders, etc., and various hydraulic or hydraulic pressure, pneumatic equipment, and the like. In particular, water jet devices that inject high-pressure water from nozzles as water pressure equipment have recently been used in various construction, civil engineering work, such as various cleaning, deburring, resin processing, metal processing, and chipping (concrete surface roughening) work. Used in the industrial field.

  An ultra-high pressure resin hose having flexibility between a high pressure generator and a nozzle is used for the water jet device. As the ultra-high pressure resin hose, for example, a surface in which a metal wire is wound as a reinforcing layer on a surface of a resin inner tube in contact with a fluid and a resin outer layer covering the outside is used is used. (Patent Document 1).

  When using an ultra-high pressure resin hose as described above in a water jet device or the like, a connection fitting (usually a core metal fitting) is used to withstand the leakage pressure of the fluid in order to seal the ultra-high pressure internal fluid at the connection. And having a fastener). Therefore, a material having high strength is used for the inner tube resin material of the ultra-high pressure resin hose. For example, in Patent Document 2, the inner tube of a high-pressure hose has a two-layer structure, one of which is formed of polyether ether ketone having excellent water impermeability and the other is polyacetal (POM) having excellent impact resistance. ) Or nylon to form a high-pressure hose for water jets with excellent durability.

Japanese Patent Laid-Open No. 11-230432 Japanese Patent Laid-Open No. 7-290616

  However, the high strength inner tube resin material used in Patent Document 2 has a low elongation at break, and the fitting is crimped due to compression when tightly crimping the fitting or peristalsis or bending when using the hose. There is a case where the inner pipe is cracked at the portion (also referred to as “caulking portion”), leading to fluid leakage.

  In the design of an ultra-high pressure resin hose, the durability of the reinforcing layer can be confirmed by an impulse test (pressure repetition test), etc., but the frequency of the inner pipe cracking in the caulking part is the compression during caulking. In addition, since uncertain factors such as peristalsis and bending at the time of using the hose are affected, it is difficult to predict and an inner pipe that is less prone to crack is desired.

  In addition, POM used as the inner tube resin material is difficult to mold, and requires high technical ability to maintain high dimensional accuracy when it is extruded into a cylindrical shape.

  Accordingly, an object of the present invention is to provide an ultra-high pressure using a resin material that has a sufficient sealing property at the crimped portion of the mouthpiece, hardly causes fluid leakage due to cracks in the inner tube, and is easy to mold the inner tube. It is providing the resin hose and the method of manufacturing this.

  The above object is an ultra-high pressure resin hose comprising an inner tube, a reinforcing layer made of metal wire, and a jacket layer, wherein the inner tube has a multilayer structure of an inner layer made of fluororesin and an outer layer made of polyamide resin. And an ultra-high pressure resin hose characterized in that the inner layer and the outer layer have a delamination strength (based on JIS K 6330-6: 2010) of 20 N / cm or more.

  An inner layer of fluororesin having a high elongation at break (also referred to as “tensile elongation at break”) and an outer layer of polyamide resin having a high strength (also referred to as “tensile yield strength”) are bonded with the above delamination strength. The inner tube is an inner tube having both high strength and breaking elongation, and cracks are not likely to occur in the caulking portion of the fitting as described above. This makes it possible to withstand ultra-high pressure resin hoses that are resistant to fluid leakage even when the fittings are tightened so that they can withstand the leakage pressure of ultra-high pressure fluids, and even when the hose is swung or bent. can do.

  In the present invention, the ultra high pressure resin hose is a resin hose having a maximum operating pressure of 100 MPa or more.

  Preferred embodiments of the ultrahigh pressure resin hose according to the present invention are as follows.

(1) The fluorine resin of the inner layer is a fluorine atom-containing ethylenic polymer having a reactive group, and the polyamide resin of the outer layer is a nylon resin. Thereby, it can be set as the inner pipe | tube which consists of an inner layer and an outer layer which show said delamination strength easily.
(2) In the inner tube, the ratio (a / b) of the layer thickness (a) of the inner layer to the layer thickness (b) of the outer layer is 0.1 or more and less than 0.3. Thereby, it can be set as the inner tube | pipe which has more sufficient tensile fracture | rupture elongation and tensile yield strength.
(3) The inner layer has a layer thickness of 0.1 to 0.5 mm. By setting the thickness of the inner layer within this range, a sufficient tensile break elongation of the inner tube can be obtained, which is advantageous in terms of cost.
(4) Furthermore, the end fitting is crimped and attached to at least one end. In this mode, the effect of preventing fluid leakage is exhibited.

  The above object is also a method for producing the ultra high pressure resin hose of the present invention, by coextruding the fluororesin composition forming the inner layer and the polyamide resin composition forming the outer layer. This is achieved by a method for producing an ultra-high pressure resin hose comprising the step of forming the inner pipe composed of an inner layer and an outer layer. By co-extrusion of the inner layer and the outer layer of the inner tube, both layers can be bonded more sufficiently, and an ultra-high pressure resin hose having an inner tube that exhibits the above delamination strength is easily manufactured. Can do.

  The ultra-high pressure resin hose of the present invention has an inner tube in which an inner layer of a fluororesin having a large tensile elongation at break and an outer layer of a polyamide resin having a large tensile yield strength are bonded with a high delamination strength. ing. The inner tube of this configuration is an inner tube having both high strength and elongation at break, and cracks are not likely to occur in the caulked portion of the fitting as described above. Therefore, according to the present invention, when the fitting is strongly crimped so as to be able to withstand the leakage pressure of the ultra-high pressure fluid, even if there is a peristalsis or bending when the hose is used, the ultra-high pressure is less likely to cause fluid leakage. A resin hose can be obtained.

  Further, since the fluororesin and the polyamide resin are resins that are relatively easy to mold, the dimensional accuracy of the inner tube can be easily ensured by molding the inner tube using them.

It is a partially cut away schematic perspective view which shows a typical example of the ultra-high pressure resin hose of this invention. It is a schematic perspective view which shows a typical example of the inner tube | pipe of the super-high pressure resin hose of this invention. It is a partially notched schematic perspective view for demonstrating the Example of the ultra-high pressure resin hose of this invention. It is a partially notched schematic plan view for demonstrating the crimping test in evaluation of the ultra-high pressure resin hose of this invention.

  Hereinafter, embodiments of the resin hose of the present invention will be described with reference to the drawings. FIG. 1 is a partially cut-out schematic perspective view showing a typical example of the ultra-high pressure resin hose of the present invention. In FIG. 1, an ultra-high pressure resin hose 20 includes an inner tube 11, a metal wire reinforcing layer 12 and a jacket layer 13 provided around the inner tube 11, and a cap 14 is crimped on one end. It is installed. Normally, the metal fitting 14 is used by being attached to both ends of the ultra-high pressure resin hose 20, but it may be attached to only one end. The end fitting 14 may be anything as long as it can withstand the use of ultra-high pressure, and is generally made of a metal such as stainless steel, and includes a core fitting inserted into the inside of the hose and a fastening fitting that is crimped from the outside of the hose. Have (not shown). In the case of an ultra-high pressure resin hose, as described above, it is necessary to squeeze this fitting tightly so that it can withstand the leakage pressure of the ultra-high pressure fluid, and there is a load on the swaged part due to peristalsis or bending when using the hose. It is easy to start and the inner pipe is easily cracked. Therefore, in the ultra-high pressure resin hose 20 of the present invention, the inner tube 11 has a multilayer structure as described below.

  FIG. 2 is a schematic perspective view showing a typical example of the inner tube of the resin hose of the present invention. In FIG. 2, the inner tube 11 includes an inner layer 11a made of a fluororesin and an outer layer 11b made of a polyamide resin. The inner layer 11a and the outer layer 11b are bonded with an interlayer peel strength (conforming to JIS K 6330-6: 2010) of 20 N / cm or more. The delamination strength between the inner layer 11a and the outer layer 11b is preferably 40 N / cm or more, and more preferably 60 N / cm.

  An inner tube in which an inner layer of fluororesin having a high tensile elongation at break and an outer layer of polyamide resin having a high tensile yield strength are bonded with the above delamination strength is an inner tube having both high strength and elongation at break. It becomes a tube, and cracks at the crimped portion of the fitting as described above hardly occur. This makes it possible to withstand a high pressure resin hose that is resistant to fluid leakage even when the fitting is tightened so that it can withstand the leakage pressure of an ultra high pressure fluid, and even when the hose is used for peristalsis or bending. can do.

  In general, since the fluororesin and the polyamide resin have low adhesiveness, the resin materials are combined so that the above delamination strength can be obtained.

  For example, the fluororesin that forms the inner layer 11a of the inner tube 11 preferably includes a fluorine atom-containing ethylenic polymer having a reactive group. In the present invention, the reactive group means an organic group that reacts with a functional group contained in the polyamide resin of the outer layer 11b. The reactive group preferably has a carbonyl group (—C (═O) —), particularly preferably a carbonate group, a carboxylic acid halide group, a carboxylic acid group, an ester group, or an acid anhydride group. Carboxylic acid halide groups are preferred. Thereby, it can be set as a fluororesin with high adhesiveness with a polyamide resin.

  The fluorine atom-containing ethylenic copolymer having a carbonyl group is one in which a carbonyl group or a carbonyl group-containing functional group is bonded to a fluorine atom-containing ethylenic polymer chain. The polymer chain is a homopolymer chain or a copolymer chain of a repeating unit derived from a fluorine atom-containing ethylenic monomer, and may contain a repeating unit derived from an ethylenic monomer not containing a fluorine atom. Examples of the fluorine atom-containing ethylenic monomer include tetrafluoroethylene, vinylidene fluoride, chlorotrifluoroethylene, vinyl fluoride, hexafluoropropylene, hexafluoroisobutene, and perfluoro (alkyl vinyl ether). When using the ethylenic monomer which does not contain a fluorine atom, ethylene, propylene, 1-butene, vinyl chloride, vinylidene chloride etc. are mentioned, for example. Specific examples of the fluororesin include Neoflon EFEP RP-5000 and RP-4000 (above, Daikin Industries), Fluon (registered trademark) LM-ETFE AH-2000, AH-3000 (above, Asahi Glass Co., Ltd.), etc. Is preferred.

  The polyamide resin forming the outer layer 11b of the inner tube 11 is a polymer containing a repeating unit of an amide bond in the molecule. Considering the adhesiveness of the inner layer 11a with the fluororesin, a nylon resin in which most of the amide bond is bonded to an aliphatic or alicyclic structure is preferable. For example, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon 66/12, nylon 46, metaxylylenediamine adipic acid polymer and mixtures thereof. Can do. In the present invention, the polyamide resin may have a structure in which a part of the polyamide resin does not have a repeating unit of an amide bond is blocked or graft-bonded. Examples of these resins include nylon 6 / polyester copolymer, nylon 6 / polyether copolymer, nylon 12 / polyester copolymer, and nylon 12 / polyether copolymer. Examples of the polyester unit include polycaprolactone and polyethylene adipate, and examples of the polyether unit include polyethylene glycol and polypropylene glycol. As the polyamide resin, nylon 12 is particularly preferable. Specifically, VESTAMID (registered trademark) L1723, L2121, L2122, X7393, L2124, L2123, X7293, LX9013, X7229, X7297, LX9011, ZL1107, ZL1105 (and above, Daicel Evonik), UBESTA (registered trademark) 3035JU3, 3030UFX1, 3030LUX, 3030JFX1, 3030JI5L, 3030JI6L, 3030JI26L (above, manufactured by Ube Industries, Ltd.) and the like are preferable.

  By using these resin materials, it is possible to easily form the inner tube 11 including the inner layer 11a and the outer layer 11b exhibiting the above delamination strength.

  Further, in the inner tube 11 of the present invention, the inner layer 11a made of a fluororesin is for improving tensile elongation at break which cannot be obtained by a single layer structure of a resin material having high tensile yield strength such as polyacetal resin or polyamide resin. If it is too thin, its effect is low, and if it is too thick, the tensile yield strength of the entire inner tube may be reduced. Therefore, in the present invention, the ratio (a / b) of the layer thickness (a) of the inner layer 11a of the inner tube 11 to the layer thickness (b) of the outer layer 11b is 0.1 or more and less than 0.3. Is preferred. If it is this range, it can be set as the inner pipe which has more sufficient tensile fracture | rupture elongation and tensile yield strength as the whole inner pipe.

  The layer thickness of the inner layer 11a is preferably 0.1 to 0.5 mm, and more preferably 0.1 to 0.3 mm. If it is the range of this layer thickness, sufficient tensile fracture elongation of the inner pipe | tube 11 can be obtained.

  Further, since the fluororesin is an expensive resin material, it is advantageous in terms of cost.

  In the present invention, the tensile yield strength (based on JIS K 6815-1: 2002) of the inner tube 11 is preferably 50 MPa or more, and more preferably 80 MPa or more. Further, the tensile elongation at break of the inner tube 11 (based on JIS K 6815-1: 2002) is preferably 200% or more, and more preferably 400% or more.

  In the ultra-high pressure resin hose 20 of the present invention, the pressure resistance is improved by the reinforcing layer 12 made of metal wire. Any metal wire may be used, and examples thereof include steel wires, brass-plated steel wires, copper wires, aluminum wires, and the like, specifically, hard steel wires (symbols SWRH72A, SWRH82A) defined in JIS G3506. Etc.) is preferably used. The reinforcing layer 12 is formed by winding or braiding them into a desired shape such as a spiral shape or a blade shape on the outer periphery of the inner tube 11.

  In order to improve the pressure resistance, the reinforcing layer 12 preferably has a multilayer structure of two or more layers, particularly four or more layers. In this case, an intermediate yarn layer (yarn) made of an organic fiber such as vinylon, polyester, nylon, or aramid and / or an intermediate layer made of an adhesive or a resin may be provided.

  In the super high pressure resin hose 20 of the present invention, the material forming the outer cover layer 13 is not particularly limited as long as it protects the reinforcing layer 12 and does not impair the effects of the present invention. In general, a thermoplastic resin is used in consideration of the material of the inner tube 11. For example, polyamide resins such as nylon, polyolefin resins such as polyethylene, polyketone resins such as polyetheretherketone (PEEK), organic resins such as polyoxymethylene, polyvinylidene chloride, polyacrylonitrile, polyethylene 2,6 naphthalate, etc. These may be used alone or in admixture of two or more.

  The ultra-high pressure resin hose 20 of the present invention can be appropriately used for an ultra-high pressure hose used for hydraulic or hydraulic pressure, pneumatic equipment, and the like. In particular, as described above, cracks in the inner tube 11 having a multi-layer structure are less likely to occur. Therefore, by using a long hose as it is freely operated, the inner tube 11 is easily cracked and bent. Can be preferably used for an ultra-high pressure resin hose used in a water jet device in which there is a risk of the occurrence of water.

  The super-high pressure resin hose of the present invention can be manufactured by a known method. For example, it can be performed as follows.

  First, using an extruder, the fluororesin composition that forms the inner layer of the inner tube is extruded into a tubular shape, and the polyamide resin composition that forms the outer layer on the outer periphery thereof is extruded into a tubular shape to form the inner tube.

  The inner layer and the outer layer of the inner tube may be extruded in order or may be co-extruded. In the case of extrusion molding, a mandrel can also be used. Since the inner layer and the outer layer can be sufficiently bonded to each other, and an inner tube composed of the inner layer and the outer layer, which easily exhibits the above delamination strength, can be formed. It is preferable to form an inner tube composed of an inner layer and an outer layer by co-extrusion with a polyamide resin composition that forms a prevention layer.

  Next, a reinforcing layer is formed on the outer periphery of the inner tube by, for example, spirally winding a metal wire with a braiding machine. When forming the reinforcing layer, an adhesive may be used between the inner tube and the reinforcing layer, or the surface of the inner tube may be roughened to improve the adhesion. The reinforcing layer preferably has a multilayer structure of 2 layers or more, particularly 4 layers or more. In this case, an intermediate yarn layer (yarn) may be spirally wound between the layers, and an adhesive may be used. Alternatively, an intermediate layer may be formed by extruding or resin.

  Next, an ultrahigh pressure resin hose can be obtained by extruding and coating a thermoplastic resin composition that forms an outer layer on the outer periphery of the reinforcing layer, and cooling and curing the resin. Thereafter, if necessary, a fitting according to the specification is crimped and attached to both ends or one end of the obtained ultrahigh pressure resin hose by a conventional method.

  Hereinafter, the present invention will be described with reference to examples.

[Examples 1 to 4, Reference Example 1]
(1) Production of Super High Pressure Resin Hose FIG. 3 is a partially cutaway schematic perspective view for explaining the super high pressure resin hose of the embodiment. The ultra-high pressure resin hose shown in FIG. 3 was produced as follows.

  Using the materials shown in Table 1, first, a fluororesin of the inner layer of the inner tube and a polyamide resin of the outer layer of the inner tube are formed into a tubular shape by coextrusion with a resin extruder so as to have the layer thickness of Table 1. Next, using a spiral machine, the first wire layer is wound in a spiral shape, and the first yarn (intermediate yarn) layer is wound in the reverse spiral shape from above. Then, the second wire layer is wound in the opposite direction to the first wire layer, and the third wire layer is wound in the opposite direction to the second wire layer. Do not form). Each wire layer is formed by winding a metal wire (hard steel wire defined in JIS G3506: symbol SWRH82A). Thereafter, the outer layer of nylon 12 is extruded on the sixth wire layer by a resin extruder.

(2) Evaluation method In each of the obtained ultrahigh pressure resin hoses, the ease of occurrence of inner pipe cracks during caulking and use (pressurization) was evaluated as follows. The number of hoses to be evaluated was n = 10 for each example and reference example.

<Casting test>
As shown in FIG. 4, each ultra-high pressure resin hose obtained was inserted into a fitting made of a core fitting and a fastening fitting, and the fastening fitting was pressurized with a predetermined pressure to fasten the hose. Then, after crimping, a pressure resistance test was performed at a maximum working pressure of 245 MPa, and the presence or absence of a crack generated in the inner tube of the crimped hose was confirmed. Specifically, it was crimped within the range of a tightening rate (18%, tolerance ± 5%) that can ensure sealing properties, and if water leakage did not occur, it was rated as “no crack”. The tightening rate shall be obtained by the following formula.

<Repetitive pressure test (impulse test)>
The obtained ultra-high pressure resin hose was repeatedly subjected to a pressure test (impulse test) in a state of being bent according to the following conditions. During the test or after the test, the case where water leakage did not occur in the total number of the evaluation targets was rated as ◯.

(Test conditions)
Minimum bending radius: 190mm (hose bending inside)
Mounting span: 400mm at the center (space between left and right mounting ports)
Test pressure: 245 MPa
Pressurization speed: 100 MPa / sec
Atmospheric temperature: 50 ° C
Pressing frequency: 20,000 times

(3) Evaluation results Table 1 shows the results.

  As shown in Table 1, the inner pipes of the ultrahigh pressure resin hoses of Examples 1 to 4 are good without cracking as in the case of the inner pipe of the polyacetal (POM) single layer of Reference Example 1 at the time of caulking. Can be caulked. Further, even during pressurization by the impulse test, all of the examples had good results without water leakage as in Reference Example 1, at a level of pressure (245 MPa) normally required as an ultra-high pressure hose. As a result, in order to achieve sufficient tensile yield strength and tensile elongation at break as an ultra-high pressure hose, it is relatively easy to use a fluororesin and a polyamide resin without using POM, which is difficult to mold, in the inner tube. It has been shown that tube shaping can be performed.

  In addition, this invention is not limited to the structure and Example of said embodiment, A various deformation | transformation is possible within the range of the summary of invention.

  According to the present invention, it is possible to provide an ultra-high pressure resin hose excellent in durability that hardly causes fluid leakage. In addition, it is possible to provide an ultra-high pressure resin hose made of a resin material that allows easy molding of the inner tube.

10 Resin hose 11 Inner pipe
11a Inner layer 11b Outer layer 12 Reinforcing layer 13 Outer layer 14 Closure

Claims (6)

An ultra-high pressure resin hose comprising an inner tube, a reinforcing layer made of metal wire, and a jacket layer,
The inner tube has a multilayer structure of an inner layer made of a fluororesin and an outer layer made of a polyamide resin, and the delamination strength of the inner layer and the outer layer (conforming to JIS K 6330-6: 2010) An ultra-high pressure resin hose characterized by being 20 N / cm or more. The ultra-high pressure resin hose according to claim 1, wherein the fluororesin of the inner layer is a fluorine atom-containing ethylenic polymer having a reactive group, and the polyamide resin of the outer layer is a nylon resin.   The ratio (a / b) of the layer thickness (a) of the inner layer to the layer thickness (b) of the outer layer in the inner tube is 0.1 or more and less than 0.3. Ultra high pressure resin hose.   The ultra-high pressure resin hose according to any one of claims 1 to 3, wherein the inner layer has a layer thickness of 0.1 to 0.5 mm.   Furthermore, the ultra high pressure resin hose of any one of Claims 1-4 by which the metal fitting is crimped and attached to at least one edge part. A method for producing the ultra-high pressure resin hose according to claim 1,
Characterized in that it includes a step of forming the inner tube composed of the inner layer and the outer layer by co-extruding the fluororesin composition forming the inner layer and the polyamide resin composition forming the outer layer. A manufacturing method of an ultrahigh pressure resin hose.

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