JP6857445B2 - Hose and its manufacturing method - Google Patents

Description

The present invention can be suitably used for, for example, toilets, faucet fittings for kitchens, washbasins and bathrooms, hot water pipes for bathroom dryers, water storage tanks, dishwashers, water pipes, and other water and hot water supply pipes. It's about possible hoses.

Conventionally, metal pipes mainly made of copper, stainless steel, etc. have been used for water and hot water supply pipes, but there is a problem that the metal pipes are hard and inferior in flexibility, resulting in poor handleability and workability. Therefore, recently, instead of metal pipes, hose fittings are crimped or clipped to both ends of a hose consisting of a highly flexible polymer material and a reinforcing layer made of metal wire or fiber thread. Has come to be used as.

In addition, the space where the water and hot water supply pipes are provided is relatively small, and the length of the hose used is short, so the hose is often forcibly bent during construction. As a result, the hose may be bent and kink may occur. In that case, the water passage may be blocked and water flow may not be possible, or the amount of water flow may be reduced, so that the hose is less likely to cause kink. Was needed. Further, in order to obtain good workability in a limited space where a water supply / hot water supply pipe is provided, it is necessary to use a hose having excellent flexibility.

From this point of view, there has been a demand for a hose that is resistant to kink due to bending during construction without impairing the flexibility of the hose. In order to meet this demand, as in Patent Documents 1 to 3, it has been proposed to bond the inner layer tube and the fiber reinforced layer or the fiber reinforced layer and the outer layer to integrate each layer. Further, as documents related to the present invention, for example, Patent Documents 4 to 10 can be cited as references.

JP-A-2006-266274: Bridgestone Japanese Unexamined Patent Publication No. 9-178057: Yokohama Rubber Japanese Patent Application Laid-Open No. 10-52887: Yokohama Rubber Japanese Patent No. 4815039: Clave Japanese Patent No. 4267395: Clave Japanese Patent No. 4898084: Clave Japanese Patent No. 4587291: Clave Japanese Patent No. 5384847: Clave Japanese Patent No. 5611521: Clave Japanese Patent No. 5538994: Clave

Here, recently, as an outer layer of a hose, an olefin-based polymer which is a flexible material having excellent water resistance, chemical resistance, weather resistance, processability, stain resistance and the like is preferably selected. However, since the olefin polymer has a low surface energy and is chemically inert, it is particularly difficult to adhere to the adjacent fiber reinforced layer.

In the hose according to Patent Document 1, the outer layer provided on the outside of the fiber reinforcing layer is composed of a polyurethane-based thermoplastic elastomer or a polyester-based thermoplastic elastomer, and by using a specific adhesive layer, the fiber reinforcing layer and the outer layer are adhered to each other. It exerts its sexuality. It is considered that the adhesive layer described in Patent Document 1 cannot obtain sufficient adhesiveness when applied to an outer layer containing an olefin polymer.

Further, the hose of Patent Document 2 uses a specific urethane-based adhesive for adhering the fiber reinforced layer surface-treated via an adhesive to the outer layer, but the specific urethane-based adhesive can be handled. There is also the problem that it is difficult. Further, it is considered that the adhesive described in Patent Document 2 cannot obtain sufficient adhesiveness when applied to an outer layer containing an olefin polymer. Furthermore, since a fiber reinforced layer that has been surface-treated via an adhesive is used, it is possible that the flexibility of the hose will be impaired.

Further, the hose of Patent Document 3 uses a maleic anhydride-modified polyolefin resin and a polyester resin as the thermoplastic adhesive resin. However, in Patent Document 3, since the maleic anhydride-modified polyolefin is used in the form of the resin as it is, sufficient adhesiveness is not obtained. Further, the material to be used is limited, for example, sufficient adhesiveness cannot be obtained unless a polyolefin-based thermoplastic resin containing an elastomer component in which at least a part thereof is crosslinked is used as the outer layer.

The present invention has been made to solve such a problem of the prior art, and an object of the present invention is to generate a kink even when an excessive mechanical external force or bending is applied. By providing excellent kink resistance and excellent flexibility, it is possible to provide a product having excellent handleability and workability as well as excellent productivity.

In order to achieve the above object, the hose according to the present invention is formed on the inner layer, the intermediate layer formed on the outer periphery of the inner layer tube, the reinforcing layer formed on the outer periphery of the intermediate layer, and the outer periphery of the reinforcing layer. The inner layer is mainly composed of crosslinked polyolefin resin, the intermediate layer is mainly composed of crosslinked polypropylene resin, and the reinforcing layer is composed of braided fiber yarn or horizontal winding. The outer layer is mainly composed of an olefin-based thermoplastic elastomer.
Further, it is considered that the crosslinked polypropylene-based resin in the intermediate layer contains a propylene ethylene copolymer, polypropylene, a styrene-based elastomer, and carbon black.
Further, in the method for manufacturing a hose according to the present invention, an inner layer mainly composed of a polyolefin resin and an intermediate layer mainly composed of a polypropylene resin are extruded at the same time, and the inner layer and the intermediate layer are irradiated with an electron beam to irradiate the inner layer with an electron beam. And the above intermediate layer are crosslinked at the same time, a reinforcing layer is formed by braiding or horizontally winding a fiber thread on the outer periphery of the intermediate layer, and an outer layer mainly composed of an olefin thermoplastic elastomer is extruded on the outer periphery of the reinforcing layer. Is what you do.

According to the present invention, by using a material mainly composed of a crosslinked polypropylene resin as the intermediate layer, even if the outer layer contains an olefin-based thermoplastic elastomer, the intermediate layer and the outer layer can be satisfactorily separated from each other via the reinforcing layer. Be glued. Therefore, even when an excessive mechanical external force or bending is applied, it has excellent kink resistance that does not generate kink, and is excellent in handleability and workability. In addition, when bending is applied, the outer layer also has smoothness that makes it difficult for wrinkles to occur in the outer layer. Further, since the material constituting the outer layer contains an olefin-based thermoplastic elastomer, it is excellent in water resistance, chemical resistance, weather resistance, processability, stain resistance, etc., and is also excellent in flexibility. Further, since the inner layer is mainly composed of a crosslinked polyolefin resin and the intermediate layer is mainly composed of a crosslinked polypropylene resin, these can be extruded at the same time and can be crosslinked at the same time by electron beam irradiation, resulting in excellent productivity. It will be.

It is a partially cutaway perspective view which shows the structure of the hose obtained by the Example of this invention. It is a partial notch side view which shows the state which connected the connection joint is attached to both ends of the hose obtained by the Example of this invention.

The inner layer material used in the present invention is composed of a flexible material such as resin or rubber. Specifically, for example, polyolefin resin, polyamide resin, polyurethane resin, polyester resin, olefin elastomer, polyurethane elastomer, polyester elastomer, styrene elastomer, natural rubber, isoprene rubber, acrylic rubber, ethylene propylene. Examples thereof include rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, and nitrile-butadiene rubber. Among these, those mainly composed of polyolefin-based resin are preferable, and those obtained by cross-linking this polyolefin-based resin are preferable. In addition, the thing mainly composed of a polyolefin resin means that the polyolefin resin occupies more than half of the number of parts by weight of the constituent material. Examples of the polyolefin resin include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polypropylene, polybutene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, and methyl ethylene-acrylate. Examples thereof include a polymer, an ethylene-ethyl acrylate copolymer, an ethylene-methyl methacrylate copolymer, and an ethylene-ethyl methacrylate copolymer. Among these, a composition containing polyethylene and an ethylene-α-olefin copolymer is more preferable because it can improve the flexibility and chlorine resistance of the hose.

Polyethylene originally has excellent chlorine resistance, and various types of polyethylene are known. However, in the present invention, polyethylene having a density of 0.942 g / cm ³ or less is appropriately selected or combined. It is preferable to use it. If the density of polyethylene ^{exceeds 0.942 g / cm 3} , the flexibility of the hose tends to decrease, and the handleability and workability of the hose obtained by the present invention tend to deteriorate. However, even if the density of polyethylene ^{exceeds 0.942 g / cm 3} , it can be used without impairing the flexibility by thinning the layer containing polyethylene or appropriately blending a material having excellent flexibility. In some cases.

The ethylene-α-olefin copolymer is a copolymer of ethylene and α-olefin, and is a material having excellent flexibility. Examples of the α-olefin include propylene, butene-1, penten-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, decene-1, dodecene-1, and the like. In particular, an ethylene-octene copolymer is preferable. Since various ethylene-α-olefin copolymers are commercially available, they may be appropriately selected and used.

If these polyethylenes having excellent flexibility and chlorine resistance and the ethylene-α-olefin copolymer having excellent flexibility are appropriately blended, an inner layer of a hose having particularly excellent flexibility and chlorine resistance can be obtained. Is possible. It is also possible to add other compounding materials to the above composition to obtain desired properties. For example, the chlorine resistance may be further improved by appropriately adding an anti-aging agent or the like. It is also conceivable to add various additives such as a metal inactivating agent, a lubricant, a filler, a flame retardant, and a cross-linking aid.

As the material used as the intermediate layer of the present invention, a material mainly composed of a polypropylene resin is used, and this polypropylene resin is a crosslinked material. In addition, the polypropylene-based resin as the main component means that the polypropylene-based resin accounts for more than half of the weight of the constituent material. Examples of the polypropylene-based resin include polypropylene, and any of isotactic, syndiotactic, and tactic with different three-dimensional regularity (tacticity) can be used. Further, polypropylene-based copolymers such as propylene-ethylene copolymer and propylene-butene copolymer can also be used. As the copolymer, either a random copolymer or a block copolymer can be used. In addition, various polypropylene polymerization methods are known, but metallocene-catalyzed polymerization is preferable because a polymer having a uniform molecular weight distribution can be obtained, and the polypropylene obtained thereby can be inserted in a few layers. By inserting 1 or 3, the structure is apparently copolymerized with ethylene.

Further, a material other than the polypropylene-based resin may be blended in the intermediate layer, and it is also possible to add other blended materials to obtain desired characteristics. For example, the above-mentioned polyolefin resin, urethane resin, polyester resin, polyamide resin, styrene copolymer resin, polyurethane elastomer, polyester elastomer, styrene elastomer, silicone rubber and the like can be blended. Among these, it is preferable to use a styrene-based elastomer, particularly a styrene-ethylene-butylene-styrene copolymer because the flexibility of the intermediate layer is improved. Further, for example, the chlorine resistance may be further improved by appropriately adding an anti-aging agent or the like. In addition, it is also conceivable to add various additives such as a metal inactivating agent, a lubricant, a filler, and a flame retardant. Examples of the filler include silica, carbon black, magnesium carbonate, calcium carbonate, magnesium silicate, aluminum silicate (clay) and the like. By blending the filler, it is possible to adjust the material strength to a desired level, particularly for improving the tensile strength. Among these, it is preferable to have carbon black. Carbon black has the effect of imparting weather resistance, and in particular, because it has conductivity, the energy of the electron beam required for cross-linking can be reduced, so that the manufacturing cost can be reduced. Further, by blending a cross-linking aid, the cross-linking efficiency can be improved and the high-temperature physical properties, particularly the high-temperature material strength can be improved. Examples of the cross-linking aid include allyl-based monomers such as triallyl cyanurate (TAC) and triallyl isocyanurate (TAIC), ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, and triethylene glycol di ( Meta) acrylate, acrylic (meth) acrylate, 1,3-butanediol di (meth) acrylate, dimethylol tricyclodecandi (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate ) Polyfunctional (meth) acrylate such as acrylate can be mentioned. The (meth) acrylate indicates either acrylate or methacrylate. Among these, polyfunctional (meth) acrylate is preferable. These additives may be in the form of a masterbatch.

In the present invention, in order to integrate the inner layer and the intermediate layer, it is preferable to perform co-crosslinking in which the inner layer and the intermediate layer are simultaneously crosslinked by molding into a tubular shape using a molding means such as coextrusion molding. The above-mentioned polyolefin resin is crosslinked because its heat resistant temperature is low, and when it is used as a hot water supply hose, the temperature of the hot water transferred in the hose may reach about 90 ° C. In this case, it is necessary to improve the durability at high temperature by performing cross-linking. Examples of the cross-linking means include electron beam cross-linking, silane cross-linking, and peroxide cross-linking. In the present invention, among these, electron beam cross-linking is preferably adopted. In the case of electron beam cross-linking, it is not necessary to add a peroxide cross-linking agent required for peroxide cross-linking or a silane coupling agent required for silane cross-linking. For example, when dicumyl peroxide (DCP) is used as the peroxide cross-linking agent, acetophenone, cumyl alcohol, methyl styrene, water and the like are produced as by-products of the cross-linking reaction, that is, decomposition residues. Further, the silane coupling agent used for silane cross-linking may remain in an unreacted state. On the other hand, in electron beam irradiation, cross-linking is possible even without additives such as peroxide cross-linking agent and silane coupling agent, and efficiency can be improved with a small amount of cross-linking aid. Therefore, the number of components eluted in the fluid can be reduced, and a material having a high degree of freedom can be selected. From this point of view, in the present invention, it is most preferable to co-crosslink the inner layer and the intermediate layer by electron beam cross-linking.

In the present invention, at least one reinforcing layer is formed on the outer periphery of the above-mentioned intermediate layer. With this reinforcing layer, sufficient breaking pressure can be applied to the hose, and greater durability can be imparted. In addition, kink resistance is improved. The reinforcing layer is composed of braided or spirally wound fiber threads. Of course, the reinforcing layer may be multi-layered. For example, when the fiber yarn is wound horizontally, it is conceivable to perform so-called SZ winding, in which a plurality of horizontal windings having different winding directions are performed.

Further, as the fiber yarn, various organic fibers, inorganic fibers and the like can be used, and for example, vinylon fiber, polyester fiber, nylon fiber, aramid fiber, rayon fiber, polyethylene fiber, polyphenylene sulfide fiber, cotton, glass fiber and the like can be used. Can be mentioned. These fibers are braided or horizontally wound with a shielding rate of 80% or less, a number of twists of 0 to 250 times / m, a number of aligned fibers of 1 to 8, a number of strokes (standing number) of 12 to 48, and a pitch of 15 to 60 mm. Is preferred, and this is selected according to the conditions of use of the hose. The shielding ratio referred to here is the ratio of the fiber yarn covering the surface of the intermediate layer. If the shielding rate exceeds 80%, it becomes difficult to integrate the intermediate layer and the outer layer through the gap, and kink is likely to occur. In addition to this fiber yarn, a metal wire such as a stainless steel wire may be appropriately mixed for reinforcement.

In the present invention, an outer layer is formed on the outer periphery of the reinforcing layer described above. As the constituent material of the outer layer, a known material is arbitrarily selected, but in the present invention, a material mainly composed of an olefin-based thermoplastic elastomer is preferable. The olefin-based thermoplastic elastomer as the main component means that the olefin-based thermoplastic elastomer accounts for more than half of the weight of the constituent material. A material other than the olefin-based thermoplastic elastomer may be blended with the constituent material of the outer layer. For example, the above-mentioned polyolefin resin, urethane resin, polyester resin, polyamide resin, styrene copolymer resin, polyurethane elastomer, polyester elastomer, styrene elastomer, silicone rubber and the like can be blended. In addition, although it is possible to put oil in the outer layer to improve flexibility, on the other hand, there is a risk of adverse effects on the inner layer due to migration and mixing with the fluid inside the hose. Therefore, depending on the use of the hose, the amount of oil added to the outer layer is preferably as small as possible, and it is more preferable that the oil component is not contained. Since such an olefin-based thermoplastic elastomer has excellent water resistance, chemical resistance, and weather resistance, the water resistance and chemical resistance of the hose can be obtained by forming an outer layer containing the olefin-based thermoplastic elastomer. , Weather resistance will be improved. Further, since such an olefin-based thermoplastic elastomer is also excellent in flexibility, it is possible to suppress a decrease in flexibility due to the formation of an outer layer.

By forming such an outer layer, it is possible to further reduce the occurrence of kink due to bending, it is difficult for dust and dirt to adhere to the surface of the hose, and the surface can be easily cleaned, which makes it resistant. The dirtiness can be improved.

Most of the hoses obtained in this way are put into actual use with connecting joints attached to both ends thereof for connecting to the mating member. As the connecting joint, one processed by metal, resin or the like is known.

In this way, since the intermediate layer and the outer layer of the hose are well integrated via the reinforcing layer, kinking occurs even when an excessive mechanical external force or bending is applied during construction or the like. It is possible to obtain excellent kink resistance that never occurs. Here, if wrinkles occur in the outer layer when bending is applied, there is a high possibility that cracks will occur from the valleys of the wrinkles and material destruction will occur, and wrinkles will occur as much as possible from the viewpoint of impairing the design. I need to keep it down. The hose described above has good adhesion between the intermediate layer and the outer layer, so that the outer layer has smoothness that does not easily cause wrinkles when bent, so that cracks due to wrinkles can be prevented. ..

Hereinafter, examples of the present invention will be described with reference to the drawings together with comparative examples.

Example FIG. 1 is a notched perspective view of the hose 1 of the present invention. First, as a material for the inner layer 2, a polyethylene resin and an ethylene-octene copolymer are mixed to prepare a composition for the inner layer. As a material for the intermediate layer 3, a propylene-ethylene copolymer, polypropylene, a styrene-ethylene-butadiene-styrene copolymer, a carbon black master batch, and a trimethylolpropane triacrylate cross-linking aid are mixed to form an intermediate layer. Make it a thing. Coextruded by an extruder so that the composition for the inner layer is on the inside and the composition for the intermediate layer is on the outside, the inner layer 2 has a wall thickness of 0.8 mm, the intermediate layer 3 has a wall thickness of 0.1 mm, and an inner diameter of 7.1 mm. It is molded into a tubular shape so as to become. Subsequently, the inner layer 2 and the intermediate layer 3 are irradiated with an electron beam, and the inner layer 2 and the intermediate layer 3 are co-crosslinked. Next, about 1670 dtex and 100 twists / m of polyester twisted yarn, SZ winding was performed on the outer circumference of the intermediate layer 3 with one aligned number, 16 strokes, and a pitch of 28 mm to form a reinforcing layer 4. Next, an olefin-based thermoplastic elastomer was extruded and coated on the outer periphery of the reinforcing layer 4 to form the outer layer 5. The hose 1 thus obtained had an inner diameter of 7.1 mm and an outer diameter of 11.1 mm.

Using the hose thus obtained as a sample, tests were conducted for kink resistance, flexibility, and joint pull-out force. Of these tests, the joint pull-out force test was performed with connection joint processing applied to both ends of the hose, as shown in FIG. The connection joint 10 used in this test is composed of a nozzle 11 made of a copper alloy or the like, a nut 12 made of a copper alloy or the like, and a sleeve 13 made of SUS304 or the like. As a method of processing the connection joint, first, in a state where the sleeve 13 before caulking is arranged on the hose 1, the nozzle 11 which has been passed through the nut 12 in advance is inserted into the hose 1. Then, the sleeve 13 was pressed and deformed with respect to the nozzle 11 in a substantially concentric cylindrical shape, and caulked. The results of the above tests are shown in Table 1.

Using the hose obtained in the examples as a sample, an evaluation test on the kink radius was performed to confirm the kink resistance (handleability, workability). As for the kink radius, each sample was bent, and the minimum radius at which the hose kinks and bends was measured. The test temperature was 25 ° C.

The hose actually used for water supply and hot water supply needs to be flexible and not easily kinked in order to improve handleability and workability. Therefore, the kink radius is preferably twice or less the outer diameter of the hose. Of course, it is better to have a smaller kink radius. Since the hose according to this embodiment has a kink radius of 14 mm, which is less than twice the outer diameter of the hose, it exhibits excellent kink resistance, and it is recognized that kink does not occur even when bent with a smaller bending radius. Was done. When the hose was cut open and checked after the test, it was confirmed that the intermediate layer and the outer layer were adhered and fixed.

Next, using the hose obtained in this example as a sample, the bending reaction force was measured as an evaluation test of flexibility (handleability, workability). As for the bending reaction force, the reaction force when bent to a radius of 50 mm was measured. The test temperature was 25 ° C.

When installing the hose in a narrow position or in a recessed position, it is necessary to bend the hose with a slight force, so it is better that the bending reaction force in this test is small, especially the bending reaction force is 5N or less. Is preferable. It was confirmed that the hose according to this example had a bending reaction force of 2.3 N and had particularly excellent flexibility.

Next, the joint pulling force of the hose obtained in this example was measured. The joint pulling force was measured by connecting the nuts 12 at both ends of the hose and the test device, gradually applying a load to the hose, and measuring the force at which the joint was pulled out. The test temperature was 25 ° C.

When used as a water / hot water supply hose, it preferably has a breaking pressure of 5 MPa or more. It was confirmed that the hose according to this example had a breaking pressure of 9.9 MPa and had a sufficient breaking pressure.

When used as a water / hot water supply hose, it is preferable to have a joint pulling force of 0.5 kN or more. It was confirmed that the hose according to this embodiment had a joint pulling force of 0.88 kN and had a sufficient joint pulling force.

As described above, the hose of the present invention can reduce the occurrence of kink and has excellent handleability and workability. Therefore, for example, it should be suitably used in a wide range of applications such as toilets, faucet fittings for kitchens, washbasins and bathrooms, hot water pipes for bathroom dryers, water storage tanks, dishwashers, water pipes, and other water and hot water supply pipes. Can be done.

1 Hose 2 Inner layer 3 Intermediate layer 4 Reinforcing layer 5 Outer layer 10 Connection joint 11 Nozzle 12 Nut 13 Sleeve

Claims (2)

It is composed of an inner layer, an intermediate layer formed on the outer periphery of the inner layer, a reinforcing layer formed on the outer periphery of the intermediate layer, and an outer layer formed on the outer periphery of the reinforcing layer.
The inner layer is mainly composed of crosslinked polyolefin resin.
The intermediate layer contains a propylene ethylene copolymer, polypropylene, a styrene elastomer, and carbon black, and the crosslinked polypropylene resin occupies more than half of the weight of the constituent material.
The reinforcing layer is made of a braided fiber yarn or a horizontal winding.
A hose in which the outer layer is mainly composed of an olefin-based thermoplastic elastomer. An intermediate layer containing an inner layer mainly composed of a polyolefin resin, a propylene ethylene copolymer, polypropylene, a styrene elastomer, and carbon black, and the crosslinked polypropylene resin occupies more than half of the weight of the constituent materials. Is extruded at the same time, the inner layer and the intermediate layer are irradiated with an electron beam to crosslink the inner layer and the intermediate layer at the same time, and a fiber thread is braided or horizontally wound around the outer periphery of the intermediate layer to form a reinforcing layer. A method for manufacturing a hose which is formed and an outer layer mainly composed of an olefin-based thermoplastic elastomer is extruded on the outer periphery of the reinforcing layer.

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