JP2016065615A - Flexible hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible hose 1 showing superior heat resistance, chemical proof and sliding characteristic.SOLUTION: A hose 2 has an inner layer 4, a middle layer 6, an outer layer 8 and a reinforcing body 10. The inner layer 4 is cylindrical in shape. The middle layer 6 covers an outer peripheral surface of the inner layer 4 and is connected to this outer peripheral surface. The outer layer 8 covers an outer peripheral surface of the middle layer 6 and is connected to the outer peripheral surface. The reinforcing body 10 is wound around the outer layer 8 in a helical manner and connected to the outer layer 8. The inner layer 4 is molded by bridge linking rubber composition containing ternary copolymer of ethylene-propylene-diene. The middle layer 6 is molded by resin composition containing copolymer of ethylene-vinyl acetate. The outer layer 8 is molded by resin composition containing vinyl chloride resin. The reinforcing body 10 is molded by resin composition containing vinyl chloride resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flexible hose that can be used for liquid transfer, gas transfer, and the like.

  A hose is used when liquid, gas, powder, particles, etc. are transferred at home, factory, plant, and the like. From the viewpoint of easy installation, a flexible hose is mainly used. This hose is made of rubber or synthetic resin.

  Japanese Unexamined Patent Application Publication No. 2003-204913 discloses a rubber hose having an inner layer and an outer layer. The inner layer base rubber is EPDM, and the outer layer base rubber is polyisoprene. EPDM is excellent in heat resistance and chemical resistance.

  Japanese Patent Application Laid-Open No. 2008-82399 discloses a hose having a main body and a reinforcing body. This reinforcing body is spirally wound around the main body. This reinforcing body suppresses crushing of the hose. This reinforcement body consists of a resin composition. The base resin of this resin composition is polyvinyl chloride. A reinforcing body made of polyvinyl chloride is excellent in moldability. The reinforcing effect of this reinforcing body is high. Further, when this reinforcing body is used on the outer periphery of the hose, this reinforcing body contributes to the sliding property of the hose.

JP 2003-204913 A JP 2008-82399 A

  As described above, EPDM is excellent in heat resistance and chemical resistance, and polyvinyl chloride contributes to improving the properties of the reinforcing body. However, a flexible hose having a reinforcing body that is excellent in heat resistance and chemical resistance, has excellent molding processability, and has a high reinforcing effect has not yet been put into practical use.

  An object of the present invention is to provide a flexible hose excellent in heat resistance, chemical resistance, molding processability of a reinforcing body, and reinforcing effect of the reinforcing body.

The flexible hose according to the present invention is
(1) cylindrical inner layer,
(2) an intermediate layer located outside the inner layer and joined to the outer surface of the inner layer;
(3) an outer layer located outside the intermediate layer and joined to the outer surface of the intermediate layer;
And (4) a reinforcing body that is spiral and joined to the outer layer. The inner layer is formed by crosslinking a rubber composition containing an ethylene-propylene-diene terpolymer. The intermediate layer is molded from a resin composition containing an ethylene-vinyl acetate copolymer. The outer layer is molded from a resin composition containing a vinyl chloride resin. The reinforcing body is molded from a resin composition containing a vinyl chloride resin.

  Preferably, the outer layer is molded from a resin composition comprising polyvinyl chloride, vinyl chloride-ethylene copolymer or vinyl chloride-ethylene-vinyl acetate terpolymer. Preferably, the resin composition of the outer layer further includes an ethylene-vinyl acetate copolymer.

  Preferably, the reinforcing body is molded from a resin composition containing polyvinyl chloride.

  In the hose according to the present invention, the inner layer containing ethylene-propylene-diene terpolymer (EPDM) contributes to heat resistance and chemical resistance. Further, in this hose, the reinforcing body containing the vinyl chloride resin is excellent in moldability and exhibits an excellent reinforcing effect. In addition, when the reinforcing body is provided so as to be exposed on the outermost periphery of the hose, the reinforcing body contributes to the sliding property of the hose. In this hose, the inner layer and the reinforcing body are firmly integrated through the intermediate layer and the outer layer. This hose combines the advantages of EPDM and the advantages of vinyl chloride resin.

FIG. 1 is a partially cutaway sectional view showing a hose according to an embodiment of the present invention. FIG. 2 is a schematic view showing a state of manufacturing the hose of FIG.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 shows a part of the flexible hose 2. In FIG. 1, the cross section of the hose 2 is shown above the center line CL. The horizontal direction in FIG. 1 is the length direction of the hose 2. The hose 2 has a tubular shape as a whole.

  The hose 2 includes an inner layer 4, an intermediate layer 6, an outer layer 8, and a reinforcing body 10. The inner layer 4 is cylindrical. The mid layer 6 is also cylindrical. The intermediate layer 6 is located outside the inner layer 4. The intermediate layer 6 covers the outer peripheral surface of the inner layer 4. The outer layer 8 is also cylindrical. The outer layer 8 is located outside the intermediate layer 6. The outer layer 8 covers the outer peripheral surface of the intermediate layer 6. The reinforcing body 10 is spirally wound on the outer peripheral surface of the outer layer 8.

  The inner layer 4 is formed by crosslinking a rubber composition. This rubber composition contains an ethylene-propylene-diene terpolymer (EPDM) as a base rubber. EPDM is excellent in heat resistance. Even if a high-temperature substance passes through the inner layer 4, the inner layer 4 is not easily damaged. EPDM is further excellent in chemical resistance. Even if an acidic or basic fluid passes through the inner layer 4, the inner layer 4 is hardly damaged.

  The rubber composition of the inner layer 4 may contain other rubber as the base rubber together with EPDM. Examples of other rubbers include polyisoprene, polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, isobutylene-isoprene copolymer, and polychloroprene.

  When the rubber composition of the inner layer 4 contains EPDM and another rubber, it is preferable that EPDM is the main component of the base rubber from the viewpoint of heat resistance and chemical resistance. The ratio of EPDM to the total amount of the base rubber is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. This ratio may be 100% by mass.

  The rubber composition of the inner layer 4 contains a crosslinking agent. A typical cross-linking agent is sulfur. When the rubber composition contains sulfur, preferably the rubber composition also contains a vulcanization accelerator. The rubber composition may be crosslinked with an organic peroxide. The rubber composition may be crosslinked with a fatty acid metal salt. The rubber composition may be crosslinked by an electron beam.

  The rubber composition of the inner layer 4 may contain additives such as a crosslinking aid, an anti-aging agent, a reinforcing material, a filler, a softener, a plasticizer, a flame retardant, and a colorant.

  The intermediate layer 6 is bonded to the outer peripheral surface of the inner layer 4. Specifically, the intermediate layer 6 is fused to the inner layer 4. The intermediate layer 6 is integrated with the inner layer 4.

  The mid layer 6 is molded from a resin composition. This resin composition contains an ethylene-vinyl acetate copolymer (EVA) as a base resin. EVA is obtained by copolymerization of an ethylene monomer and a vinyl acetate monomer. EVA contains an ethylene-based component and a vinyl acetate-based component in the molecular chain. As described above, the inner layer 4 contains EPDM. The intermediate layer 6 containing an ethylene-based component is excellent in bondability with the inner layer 4. In the hose 2, the intermediate layer 6 is difficult to peel from the inner layer 4. As will be described in detail later, the intermediate layer 6 is also excellent in bondability with the outer layer 8.

  As a preferable EVA, a trade name “Ultrasen” of Tosoh Corporation is exemplified. Specifically, the trade name “Ultrasen 630” in which the molar ratio of vinyl acetate is 15% and the trade name “Ultrasen 760” in which the molar ratio of vinyl acetate is 42% can be mentioned.

  The resin composition of the mid layer 6 may contain other resins as the base resin together with EVA. Examples of other resins include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyester, and polyamide.

  When the resin composition of the mid layer 6 includes EVA and another resin, EVA is preferably the main component of the base resin from the viewpoint of bondability. The ratio of EVA with respect to the total amount of the base resin is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. This ratio may be 100% by mass.

  The resin composition of the mid layer 6 may contain additives such as anti-aging agents, fillers, softeners, plasticizers, flame retardants, and colorants.

  The outer layer 8 is joined to the outer peripheral surface of the intermediate layer 6. Specifically, the outer layer 8 is fused to the intermediate layer 6. The outer layer 8 is integrated with the intermediate layer 6.

  The outer layer 8 is molded from a resin composition. This resin composition contains a vinyl chloride resin as a base resin. The vinyl chloride resin contains a vinyl chloride component in the molecular chain. As described above, the intermediate layer 6 includes EVA. This EVA contains a vinyl acetate component in the molecular chain. The outer layer 8 containing a vinyl chloride resin is excellent in bondability with the intermediate layer 6 containing EVA. In the hose 2, the outer layer 8 is difficult to peel from the intermediate layer 6. As will be described in detail later, the outer layer 8 is also excellent in bondability with the reinforcing body 10.

  Preferred vinyl chloride resins include polyvinyl chloride (particularly soft polyvinyl chloride), vinyl chloride-ethylene copolymer, and vinyl chloride-ethylene-vinyl acetate terpolymer. From the viewpoint of bondability with the mid layer 6, a vinyl chloride-ethylene copolymer and a vinyl chloride-ethylene-vinyl acetate terpolymer are preferred. The most preferred vinyl chloride resin is vinyl chloride-ethylene-vinyl acetate terpolymer. Two or more vinyl chloride resins may be used in combination with the outer layer 8.

  As a specific example of the vinyl chloride-ethylene copolymer, a product name “Taiyo PVC TE” series by Taiyo PVC Co., Ltd. may be mentioned. Specific examples of the vinyl chloride-ethylene-vinyl acetate terpolymer include Sekisui Chemical Co., Ltd. trade name “Sekisui PVC-TG” series and Taiyo PVC Co., Ltd. trade name “Taiyo PVC TG” series. .

  The resin composition of the outer layer 8 may contain other resins as the base resin together with the vinyl chloride resin. Examples of other resins include polyethylene, polypropylene, polystyrene, polyester, polyamide, and ethylene-vinyl acetate copolymer.

  When the resin composition of the outer layer 8 includes a vinyl chloride resin and another resin, it is preferable that the vinyl chloride resin is a main component of the base resin from the viewpoint of the bondability with the reinforcing body 10. The ratio of the vinyl chloride resin to the total amount of the base resin is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. This ratio may be 100% by mass.

  A preferred embodiment in the case where the resin composition of the outer layer 8 includes a vinyl chloride resin and another resin includes a blend of polyvinyl chloride and EVA. From the viewpoint of the bondability with the intermediate layer 6, the bondability with the reinforcing body 10, and the economical efficiency, the mass ratio of polyvinyl chloride and EVA in this blend is preferably 20/80 or more and 80/20 or less, and 30/70. Above 70/30 is particularly preferable.

  As a preferable EVA when the base material resin of the outer layer 8 contains polyvinyl chloride and EVA, the trade name “Soabrene” of Nippon Synthetic Chemical Industry Co., Ltd. is exemplified. When the resin composition of the outer layer 8 contains polyvinyl chloride and EVA, various commercially available soft polyvinyl chlorides can be used.

  The resin composition of the outer layer 8 may contain additives such as anti-aging agents, fillers, softeners, plasticizers, flame retardants, and colorants.

  As described above, the EVA of the intermediate layer 6 includes an ethylene-based component and a vinyl acetate-based component in the molecular chain. The ethylene component contributes to the bonding between the inner layer 4 and the intermediate layer 6. The vinyl acetate component contributes to the bondability between the intermediate layer 6 and the outer layer 8. From the viewpoint of bondability with the inner layer 4, the molar ratio of the ethylene-based component to the vinyl acetate-based component is preferably 50/50 or more, and particularly preferably 70/30 or more. From the viewpoint of bondability with the outer layer 8, this molar ratio is preferably 85/15 or less, particularly preferably 80/20 or less.

  The reinforcing body 10 is linear. The cross-sectional shape of the reinforcing body 10 is an ellipse. The cross-sectional shape of the reinforcing body 10 may be a circle. The reinforcing body 10 is joined to the outer peripheral surface of the outer layer 8. Specifically, the reinforcing body 10 is fused to the outer layer 8. The reinforcing body 10 is integrated with the outer layer 8. The reinforcing body 10 does not cover the entire outer peripheral surface of the outer layer 8. On the outer peripheral surface of the outer layer 8, portions covered with the reinforcing body 10 and portions not covered are alternately present along the length direction. The reinforcing body 10 does not hinder the flexibility of the hose 2.

  The reinforcing body 10 is formed from a resin composition. This resin composition contains a vinyl chloride resin as a base resin. Vinyl chloride resin is excellent in slipperiness. The reinforcing body 10 containing this resin is easy to handle.

  As described above, the outer layer 8 contains a vinyl chloride resin. The reinforcing body 10 containing a vinyl chloride resin is excellent in bondability with the outer layer 8. In the hose 2, the reinforcing body 10 is difficult to peel from the outer layer 8.

  The reinforcing body 10 contributes to the strength of the hose 2. The cross-sectional shape (substantially a circle) of the hose 2 is held by the reinforcing body 10. Preferably, the base resin of the reinforcing body 10 has higher hardness than the base resin of the outer layer 8. The outer layer 8 has a hardness H1 (type A durometer) of preferably 80 or less, particularly preferably 65 or less. The hardness H1 is preferably 50 or more. The hardness H2 (type D durometer) of the reinforcing body 10 is preferably 50 or more, particularly preferably 60 or more. The hardness H2 is preferably 90 or less, and particularly preferably 85 or less.

  Examples of preferable vinyl chloride resins include polyvinyl chloride, vinyl chloride-ethylene copolymer, and vinyl chloride-ethylene-vinyl acetate terpolymer. Hard polyvinyl chloride is preferable from the viewpoints of slipperiness, moldability, strength, rigidity, and economy. Various commercially available rigid polyvinyl chlorides can be used for the reinforcing body 10.

  The resin composition of the reinforcing body 10 may contain other resins as the base resin together with the vinyl chloride resin. Examples of other resins include polyethylene, polypropylene, polystyrene, polyester, polyamide, and ethylene-vinyl acetate copolymer.

  When the resin composition of the reinforcing body 10 includes a vinyl chloride resin and another resin, the vinyl chloride resin is used from the viewpoints of bondability with the outer layer 8, strength and slipperiness of the hose 2, and moldability of the reinforcing body. Is preferably the main component of the base resin. The ratio of the vinyl chloride resin to the total amount of the base resin is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more. This ratio may be 100% by mass.

  The resin composition of the reinforcing body 10 may contain additives such as anti-aging agents, fillers, softeners, plasticizers, flame retardants, and colorants.

  As is clear from FIG. 1, the radially inner portion of the reinforcing body 10 is embedded in the resin composition of the outer layer 8. By this embedding, the reinforcing body 10 is firmly joined to the outer layer 8. The remaining portion of the reinforcing body 10 is located on the radially outer side with respect to the outer layer 8. In other words, a part of the reinforcing body 10 protrudes. That is, in this embodiment, the reinforcing body 10 is provided so as to be exposed on the outermost periphery of the hose 2. Therefore, the reinforcing body 10 mainly comes into contact with an object existing around the hose 2. This reinforcing body 10 contributes to the slipperiness of the hose 2.

  In this hose 2, the inner layer 4 containing EPDM contributes to heat resistance and chemical resistance. In the hose 2, the reinforcing body 10 containing a vinyl chloride resin further contributes to the crushing strength and slipping property of the hose 2. EPDM and vinyl chloride resin are inferior in bondability. In the hose 2, the inner layer 4 and the reinforcing body 10 are firmly integrated through the intermediate layer 6 and the outer layer 8. The hose 2 has both the advantages of EPDM and the advantages of vinyl chloride resin.

  The hose 2 may have other layers or components. For example, the hose 2 may have a spiral reinforcing body positioned between the inner layer 4 and the intermediate layer 6. This reinforcing body can be formed from a resin composition containing a hard resin. This reinforcement body may be formed from a metal. The hose 2 may have a spiral reinforcing body located inside the inner layer 4.

  The hose 2 may have a reinforcing layer made of fibers. This reinforcing layer may be located between the inner layer 4 and the intermediate layer 6, or may be located between the intermediate layer 6 and the outer layer 8. This reinforcing layer may be embedded in the intermediate layer 6. The reinforcing layer can be embedded in the intermediate layer 6 by applying the resin composition of the intermediate layer 6 in a semi-molten state to the front side surface and the back side surface of the reinforcing layer.

  Examples of the reinforcing layer made of fibers include blade braid, knit, and woven fabric. A reinforcing layer in which a large number of cords are arranged in parallel may be used. Examples of the extending direction of the cord include a circumferential direction, an axial direction, and a spiral direction.

  In the hose 2 shown in FIG. 1, the reinforcing body 10 is exposed on the outermost periphery of the hose 2. This reinforcing body does not necessarily have to be exposed. For example, the outer peripheral surface of the reinforcing body provided outside the outer layer may be coated and covered with the same material as that constituting the outer layer. This reinforcing body may be embedded in the outer layer thicker than the cross section of the reinforcing body. In these embodiments, the reinforcing body and the outer layer are more reliably joined and integrated. Also in these embodiments, as in the embodiment shown in FIG. 1, an effect that the molding processability of the reinforcing body is good and an effect that the crushing resistance of the hose is effectively improved by the reinforcing body are obtained. .

  FIG. 2 shows an example of a method for manufacturing the hose 2 of FIG. The apparatus 12 used in this manufacturing method includes a forming shaft 14, a heater 16 and a cooler 18. The forming shaft 14 is driven by a motor (not shown), and performs a helical rotational feed movement with a predetermined pitch. A material is supplied to the forming shaft 14 and the material is spirally wound. This material is sent out in the right direction of FIG. 2, and the hose 2 is manufactured. This device 12 is known. A manufacturing method in which the apparatus 12 is used is referred to as a “spiral method”.

  In the manufacturing method using the apparatus 12 shown in FIG. 2, the rubber composition is extruded from an extruder (not shown). This rubber composition contains EPDM as a base rubber. The first strip 20 is obtained by extrusion. In this first strip 20, the rubber is uncrosslinked. As shown in FIG. 2, the cross-sectional shape of the first strip 20 is a parallelogram. The first strip 20 has two side edges 22. The cross-sectional shape of the first strip 20 may be a rectangle.

  The first strip 20 is supplied to the apparatus 12 and is spirally wound around the forming shaft 14 at a predetermined pitch. The winding is performed such that the side edge 22 comes into contact with the adjacent side edge 22. By this winding, a cylindrical inner layer 4 (see also FIG. 1) is formed. The inner layer 4 is heated by a heater 16. The inner layer 4 is heated by heating, and a crosslinking reaction occurs in the rubber composition. The rubber composition may be heated by the molding shaft 14 instead of or together with the heater 16.

  The resin composition containing EVA is extruded in a semi-molten state, and the second strip 24 is obtained. The second strip 24 is supplied to the apparatus 12 and is spirally wound at a predetermined pitch on the inner layer 4 where the crosslinking reaction is in progress. A cylindrical intermediate layer 6 (see also FIG. 1) is formed by winding. The intermediate layer 6 is joined to the inner layer 4. In this embodiment, the width W of the second strip 24 is twice the helical pitch. Accordingly, the winding proceeds while the second strips 24 overlap. When the viscosity of the resin composition is low, the intermediate layer 6 may be obtained by applying the resin composition to the inner layer 4.

  A reinforcing layer made of fibers may be supplied to the device 12 simultaneously with the formation of the intermediate layer 6 or before and after the formation of the intermediate layer 6. When the reinforcing layer is a blade braid, the blade braid may be manufactured immediately before supply.

  A resin composition containing a vinyl chloride resin is extruded in a semi-molten state, and the third strip 26 is obtained. As shown in FIG. 2, the cross-sectional shape of the third strip 26 is a parallelogram. The third strip 26 has two side edges 28. The cross-sectional shape of the third strip 26 may be a rectangle.

  Furthermore, the other resin composition containing the vinyl chloride resin is extruded in a semi-molten state, and the strap 30 is obtained. The cross-sectional shape of the strap 30 is substantially a circle. In the present embodiment, the third strip 26 and the strap 30 are coextruded. Simultaneously with the extrusion, the third strip 26 and the strap 30 are integrated. The third strip 26 and the strap 30 are supplied to the apparatus 12 and are spirally wound at a predetermined pitch on the semi-molten intermediate layer 6. The winding is performed such that the side edge 28 comes into contact with the adjacent side edge 28. A cylindrical outer layer 8 (see also FIG. 1) is formed from the third strip 26 by winding. The spiral reinforcing body 10 (see also FIG. 1) is formed from the strap 30 by winding. The outer layer 8 is integrated with the intermediate layer 6. The third strip 26 and the strap 30 may be supplied to the device 12 separately.

  In the inner layer 4 passing under the cooler 18, the crosslinking reaction has sufficiently progressed. Cooling water is injected from the cooler 18 toward the molding machine. With this cooling water, the inner layer 4, the intermediate layer 6, the outer layer 8 and the reinforcing body 10 are cooled. The crosslinking reaction in the inner layer 4 is stopped by cooling. The resin composition is solidified by cooling. The shape of the hose 2 is determined by cooling. Cooling may be done by gas.

  By the method using this device 12, the hose 2 can be easily manufactured.

  The hose according to the present invention can be used for transferring water (hot water and cold water), oil, gas, powder, granules and the like.

DESCRIPTION OF SYMBOLS 2 ... Flexible hose 4 ... Inner layer 6 ... Intermediate layer 8 ... Outer layer 10 ... Reinforcement body 12 ... Apparatus 14 ... Molding shaft 20 ... First strip 24 ... Second strip 26 ... Third strip 30 ... Strap

Claims (4)

Cylindrical inner layer,
An intermediate layer located outside the inner layer and joined to the outer surface of the inner layer;
An outer layer located outside the intermediate layer and joined to the outer surface of the intermediate layer;
And a reinforcing body that is spiral and joined to the outer layer,
The inner layer is formed by crosslinking a rubber composition containing an ethylene-propylene-diene terpolymer,
The intermediate layer is molded from a resin composition containing an ethylene-vinyl acetate copolymer,
The outer layer is molded from a resin composition containing a vinyl chloride resin,
A flexible hose in which the reinforcing body is molded from a resin composition containing a vinyl chloride resin.   The hose according to claim 1, wherein the outer layer is molded from a resin composition containing polyvinyl chloride, vinyl chloride-ethylene copolymer or vinyl chloride-ethylene-vinyl acetate terpolymer.   The hose according to claim 2, wherein the resin composition of the outer layer further contains an ethylene-vinyl acetate copolymer.   The hose according to any one of claims 1 to 3, wherein the reinforcing body is molded from a resin composition containing polyvinyl chloride.

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