JP2007106082A - Low-permeability resin hose and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-permeability resin hose which is excellent not only in interlaminar bondability but also in low permeability for fuel, a coolant, etc. <P>SOLUTION: In this low-permeability resin hose, an intermediate layer 2, a binding layer 3 and an outer layer 6 are sequentially formed on the outer periphery of a tubular inner layer 1; the inner layer 1 is formed of a material for the inner layer, which is mainly composed of a polyarylenesulfide resin; the intermediate layer 2 is composed of a single-layer film or a multilayer film, which consists of a chrome oxide film; and the binding layer 3 is formed of a material for the binding layer, which is mainly composed of a polyamide resin (A) or a modified polyolefine resin; and the outer layer 6 is formed of a material for the outer layer, which is mainly composed of an aliphatic polyamide resin. The polyamide resin (A) is at least one polyamide resin which is selected from the group consisting of a polyamide 6, a polyamide 66, a polyamide 6 copolymer, and a polyamide 66 copolymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a low-permeability resin hose and a method for producing the same. Specifically, gasoline, alcohol mixed gasoline (gasohol), alcohol, hydrogen, light oil, dimethyl ether, diesel, CNG (compressed natural gas), The present invention relates to a low permeation resin hose excellent in permeation resistance to refrigerants such as LPG (liquefied petroleum gas) or refrigerants such as chlorofluorocarbons, alternative chlorofluorocarbons, water and carbon dioxide used in air conditioners and radiators and the like, and a method for producing the same.

  Due to the increasing global environmental awareness, regulations on the evaporation of hydrocarbons from fuel hoses for automobiles and the like have been strengthened, and in particular, strict transpiration regulations have been legislated in the United States. Under such circumstances, a hose having a multilayer structure having a low fuel permeation layer made of a fluororesin has been proposed in order to comply with the regulation of the amount of hydrocarbon transpiration.

  The multi-layer hose using the fluororesin has relatively low fuel permeation performance, but when more severe fuel low permeation performance is required, the thickness of the fluororesin layer must be increased, Therefore, there is a drawback that the hose becomes expensive.

  Thus, polyarylene sulfide resin, particularly polyphenylene sulfide (PPS) resin, has attracted attention as a resin that has better fuel permeation performance than fluorine-based resin. Since this PPS resin is excellent in low fuel permeation performance, sufficient fuel low permeation performance can be obtained even if it is relatively thin. Therefore, it is advantageous in terms of price as compared with a hose in which a low fuel permeation layer is formed using a fluorine-based resin.

  As described above, as a hose having a low fuel permeation layer made of PPS resin, for example, an outer layer made of a thermoplastic resin (polyamide resin or the like) other than PPS resin on the outer periphery of the inner layer (low fuel permeation layer) made of PPS resin. Has been proposed (see Patent Document 1).

On the other hand, as a refrigerant transport hose used for a car air conditioner or the like, a multilayer hose in which a vapor deposition film is laminated and dry-plated has been proposed in order to improve low permeability. For example, a low-permeability rubber hose has been proposed in which a metal thin film or a metal compound thin film is formed on a synthetic resin inner tube by dry plating, and then a rubber layer is heated and cured via an adhesive (see Patent Document 2). . A rubber hose in which a metal vapor-deposited film is spirally wound through a hot melt adhesive has been proposed (see Patent Document 3).
JP 10-138372 A Japanese Patent No. 2870784 Japanese Patent Laid-Open No. 2001-235068

  Since the multilayer fuel tube described in Patent Document 1 has poor interlayer adhesion between an inner layer made of PPS resin and an outer layer made of polyamide resin or the like, a large amount of polyamide resin is compounded with PPS resin which is an inner layer material. It is necessary to use However, since the polyamide resin is a fuel-impermeable resin, if it is blended in a large amount, the blending ratio of the PPS resin decreases, and the low fuel permeability of the inner layer decreases.

  Moreover, the thing of the said patent document 2 has the difficulty that a thin film peels from a synthetic resin and a refrigerant | coolant leaks about the film-forming on a synthetic resin, since the film | membrane which considered adhesiveness is not made | formed. In addition, since an adhesive is used for bonding the outer layer and the thin film, there is also a manufacturing problem that production efficiency is poor.

  Next, since the thing of the said patent document 3 does not consider the interface adhesiveness of a resin film and a vapor deposition film regarding a metal vapor deposition film, there exists a difficulty that a thin film peels from a synthetic resin and a refrigerant | coolant leaks. Further, when used for fuel transportation of alcohol-added gasoline or the like, there is also a problem that the fuel permeates from the hot melt adhesive layer at the overlap of the vapor deposition film.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a low-permeability resin hose that is excellent in interlayer adhesion and low in permeability to fuels, refrigerants, and the like, and a method for producing the same.

In order to achieve the above object, the present invention provides a low-permeability resin hose in which an intermediate layer, a bonding layer and an outer layer are sequentially formed on the outer periphery of a tubular inner layer, and the inner layer mainly comprises a polyarylene sulfide resin. The intermediate layer is formed of a single layer film or a multilayer film having a chromium-based oxide film as a constituent film, and the bonding layer is formed of the following polyamide resin (A) or A low-permeability resin hose which is formed using a bonding layer material mainly composed of a modified polyolefin resin, and wherein the outer layer is formed using an outer layer material mainly composed of an aliphatic polyamide resin. The gist of
(A) At least one polyamide resin selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 copolymer and polyamide 66 copolymer.

Further, the present invention provides at least one physical vapor deposition selected from the group consisting of sputtering, ion plating, and vacuum vapor deposition on the outer periphery of the inner layer formed using the inner layer material mainly composed of polyarylene sulfide resin. After forming an intermediate layer composed of a single layer film or a multilayer film with a chromium-based oxide film as a constituent film, the following polyamide resin (A) or modified polyolefin-based resin is a main component on the surface of the intermediate layer. A second manufacturing method of a low-permeability resin hose in which a tie layer is formed using a tie layer material and an outer layer is formed on the outer peripheral surface of the tie layer using an outer polyamide material as a main component is a second method. The gist.
(A) At least one polyamide resin selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 copolymer and polyamide 66 copolymer.

  The inventors of the present invention have made extensive studies in order to obtain a low-permeability resin hose that has excellent interlayer adhesion and low permeability to fuels and refrigerants. As a result, an intermediate layer composed of a single layer film or a multilayer film having a chromium-based oxide film as a constituent film is formed on the outer periphery of the inner layer formed using the inner layer material mainly composed of polyarylene sulfide resin. In addition, a bonding layer is formed on the outer periphery using the above-mentioned polyamide resin (A) or a bonding layer material mainly composed of a modified polyolefin resin, and an outer layer is formed using an aliphatic polyamide resin on the outer periphery of the intermediate layer. The present inventors have found that the intended purpose can be achieved by the low-permeability resin hose formed by forming the present invention. That is, as described above, on the outer periphery of the inner layer formed using the inner layer material mainly composed of polyarylene sulfide resin, the intermediate layer composed of a single layer film or a multilayer film including a chromium-based oxide film. When the is formed, an excellent low permeation performance with respect to a fuel, a refrigerant and the like can be obtained by a synergistic barrier effect of the polyarylene sulfide resin and the chromium-based oxide film. The chromium-based oxide thin film is active when formed on the outer periphery of the inner layer mainly composed of polyarylene sulfide resin immediately after the chromium-based metal evaporated under high vacuum reacts with oxygen in a highly active state. It is presumed that because of the electron withdrawing property of chromium and the porous property of the chromium-based oxide film, it becomes easy to chemically bond with the S component of the polyarylene sulfide resin as the inner layer. In addition, when a bonding layer is formed using the above-mentioned polyamide resin (A) or a bonding layer material mainly composed of a modified polyolefin-based resin, adhesion with the chromium oxide film in the intermediate layer and aliphatic polyamide resin in the outer layer Therefore, the interlayer adhesion between the intermediate layer and the bonding layer and between the bonding layer and the outer layer is improved.

  Thus, the low-permeability resin hose of the present invention is a single-layer film having a chromium-based oxide film as a constituent film on the outer periphery of an inner layer formed using an inner layer material mainly composed of polyarylene sulfide resin. Since the intermediate layer composed of the multilayer film is formed, excellent low permeation performance with respect to fuel, refrigerant, and the like can be obtained by the synergistic barrier effect of the polyarylene sulfide resin and the chromium-based oxide film. The chromium-based oxide thin film is active when formed on the outer periphery of the inner layer mainly composed of polyarylene sulfide resin immediately after the chromium-based metal evaporated under high vacuum reacts with oxygen in a highly active state. It is presumed that because of the electron withdrawing property of chromium and the porous property of the chromium-based oxide film, it becomes easy to chemically bond with the S component of the polyarylene sulfide resin as the inner layer. In addition, since the bonding layer is formed using the above-mentioned polyamide resin (A) or a bonding layer material mainly composed of a modified polyolefin-based resin, adhesion to the intermediate chromium oxide film and aliphatic outer layer The adhesion with the polyamide resin is improved, and the interlayer adhesion between the intermediate layer and the bonding layer and between the bonding layer and the outer layer is improved.

  Moreover, the low-permeability resin hose in which the outer peripheral surface of the inner layer is plasma-treated and the intermediate layer is directly formed on the plasma-treated surface has an effect of further improving the interlayer adhesion between the inner layer and the intermediate layer.

  And the low-permeability resin hose of the present invention is formed on the outer periphery of the inner layer formed using the inner layer material by at least one physical vapor deposition method selected from the group consisting of sputtering, ion plating and vacuum vapor deposition. After forming an intermediate layer composed of a single layer film or a multilayer film comprising a chromium-based oxide film, on the surface of the intermediate layer, for a bonding layer mainly composed of the polyamide resin (A) or the modified polyolefin-based resin It can be manufactured by forming a bonding layer using a material and forming an outer layer on the outer peripheral surface of the bonding layer using an outer layer material mainly composed of an aliphatic polyamide resin. As a result, it is possible to easily produce a low-permeability resin hose having better interlayer adhesion without using an adhesive, thereby improving production efficiency. Further, the intermediate layer is formed into a single layer film or a multilayer film having a chromium-based oxide film as a constituent film by at least one physical vapor deposition method selected from the group consisting of sputtering, ion plating and vacuum vapor deposition. In addition, the low permeability to the fuel and the refrigerant is improved, the interlayer adhesion of the hose is improved, and the adhesive force can be maintained at 20 N / cm or more (target value).

  Next, embodiments of the present invention will be described in detail.

  For example, as shown in FIG. 1, the low-permeability resin hose of the present invention has an intermediate layer 2 formed on the outer peripheral surface of a tubular inner layer 1, a bonding layer 3 formed on the outer peripheral surface, and an outer layer on the outer peripheral surface. 6 is formed.

  In the present invention, the inner layer 1 is formed by using an inner layer material mainly composed of polyarylene sulfide resin, and the intermediate layer 2 is a single layer film having a chromium-based oxide film as a constituent film or It is composed of a multilayer film, the bonding layer 3 is formed using a material for a bonding layer mainly composed of the polyamide resin (A) or a modified polyolefin resin, and the outer layer 6 is made of an aliphatic polyamid resin. These are the biggest features. According to the present invention, as described above, interlayer adhesiveness is improved without using an adhesive, and low permeation performance with respect to fuel, refrigerant, and the like is improved.

  In the present invention, the main component means a component that generally occupies a majority of the whole, and includes the case where the whole consists only of the main component.

  Examples of the polyarylene sulfide (PAS) resin include a repeating unit represented by the structural formula [—Ar—S—] [wherein Ar is an arylene group (divalent aromatic hydrocarbon group) and S is sulfur]. Is a polymer containing 70 mol% or more of the total. That is, when the proportion of the repeating unit represented by the above structural formula is less than 70 mol% of the whole, there are few original crystal components that are characteristic of the crystalline polymer, and the mechanical strength may be insufficient. It is.

  And as a specific example of the said PAS resin, what contains 70 mol% or more of the whole repeating unit represented by following General formula (1) is mention | raise | lifted.

  In the general formula (1), R is substituted with an alkyl group having 6 or less carbon atoms or an alkoxyl group, a phenyl group, a carboxyl group or a metal base thereof, an amino group, a nitro group, or a halogen such as fluorine, chlorine or bromine. Represents a substituent. Moreover, m shows the integer of 0-4. The average degree of polymerization (n) is usually n = 10 to 300.

  Further, the PAS resin may be a homopolymer of the repeating unit represented by the general formula (1), but the co-polymerization with the structural unit other than the repeating unit represented by the general formula (1). They can be combined. Examples of such structural units include m-phenylene sulfide units, o-phenylene sulfide units, p, p'-diphenylene ketone sulfide units, p, p'-diphenylene sulfone sulfide units, p, p'-biphenylenes. Examples thereof include a sulfide unit, p, p′-diphenylenemethylene sulfide unit, p, p′-diphenylenecumenyl sulfide unit, and naphthyl sulfide unit. The molecular structure of the polymer having the structural unit may be any of a linear structure, a branched structure, or a crosslinked structure, and a polymer having these structural units may be blended and used.

  In addition, the PAS resin may be one having improved moldability by increasing the melt viscosity by oxidative crosslinking or thermal crosslinking of the polymer having the structural unit.

  Among the PAS resins, a polyphenylene sulfide (PPS) resin is preferable from the viewpoint of cost and the like. As the PPS resin, for example, those having a repeating unit represented by the following general formula (2) are preferable. The PPS resin may have a functional group in the molecular structure (including molecular ends). Examples of the functional group include an epoxy group, a hydroxyl group, a carboxylic acid anhydride residue, a carboxylic acid group, an acrylate group, a carbonate group, and an amino group.

  The melt viscosity of the PPS resin is not particularly limited as long as melt kneading is possible, but is preferably in the range of 5 to 2000 Pa · s (320 ° C., shear rate 1000 sec −1), particularly preferably 10 to 500 Pa · s. Is within the range.

  The inner layer material may be blended with a thermoplastic elastomer together with the PAS resin in order to improve flexibility and impact resistance. The thermoplastic elastomer is preferably meltable, mixed and dispersible at the temperature at which the PAS resin is kneaded. From this point, an elastomer having a melting point of 300 ° C. or less and having rubber elasticity at room temperature is preferable. Among the above-mentioned thermoplastic elastomers, those having a glass transition point of −40 ° C. or lower are preferable in view of improving heat resistance, ease of mixing, and low-temperature impact resistance, because they have rubber elasticity even at low temperatures. The glass transition point is preferably as low as possible, but is usually preferably in the range of -180 to -40 ° C, particularly preferably in the range of -150 to -40 ° C.

  The thermoplastic elastomer is a thermoplastic having at least one functional group selected from the group consisting of epoxy groups, amino groups, hydroxyl groups, carboxyl groups, mercapto groups, isocyanate groups, vinyl groups, acid anhydride groups, and ester groups. An elastomer is preferable from the viewpoint of improving low-temperature impact resistance, and among these, a functional group derived from a carboxylic acid such as an epoxy group or an acid anhydride, an acid, or an ester has a high affinity with a PAS resin. This is particularly preferable.

  The thermoplastic elastomer can be obtained, for example, by copolymerization of α-olefins and vinyl polymerizable compounds having the functional group. Examples of the α-olefins include α-olefins having 2 to 8 carbon atoms such as ethylene, propylene, and butene-1. Examples of the vinyl polymerizable compounds having the above functional group include α, β-unsaturated carboxylic acids such as (meth) acrylic acid and (meth) acrylic acid esters and alkyl esters thereof, maleic acid, fumaric acid, and itacon. Examples include acids, other unsaturated dicarboxylic acids having 4 to 10 carbon atoms, mono- and diesters thereof, α, β-unsaturated dicarboxylic acids such as acid anhydrides and derivatives thereof, glycidyl (meth) acrylate, and the like.

  Among these, the molecule has at least one functional group selected from the group consisting of an epoxy group, amino group, hydroxyl group, carboxyl group, mercapto group, isocyanate group, vinyl group, acid anhydride group, and ester group. An ethylene-propylene copolymer or an ethylene-butene copolymer is preferably used, and an ethylene-propylene copolymer or an ethylene-butene copolymer having a carboxyl group is more preferable.

  The mixing ratio of the PAS resin and the thermoplastic elastomer during the mixing is preferably 1 to 50 parts of the thermoplastic elastomer with respect to 99 to 50 parts of the PAS resin, and more than 99 to 50 parts by weight of the PAS resin. The amount of the plastic elastomer is particularly preferably 5 to 50 parts by weight. When the blending amount of the thermoplastic elastomer is within the above range, the fuel barrier property and the low temperature collision resistance are further improved.

  In addition, the inner layer material used in the present invention may appropriately contain an organic compound having a functional group, an impact resistance improver, an antiaging agent, a flame retardant, and the like together with the PAS resin.

  The organic compound having the functional group is not particularly limited, and examples thereof include ethylene-glycidyl methacrylate (EGMA), modified EGMA, ethylene-glycidyl methacrylate-vinyl acetate terpolymer, ethylene-glycidyl methacrylate-methyl acrylate terpolymer. Copolymer, ethylene-methyl acrylate copolymer, ethylene-methyl acrylate-acrylic acid terpolymer, ethylene-ethyl acrylate copolymer (EEA), modified EEA, modified ethylene-ethyl acrylate-maleic anhydride copolymer Polymer, ethylene-methacrylate copolymer, acrylic rubber, ethylene-vinyl acetate copolymer (EVA), modified EVA, modified polypropylene (PP), modified polyethylene (PE), ethylene-acrylic acid ester-maleic anhydride ternary Mutual weight Epoxidized styrene-butadiene-styrene block copolymer (SBS), epoxidized styrene-ethylene-butadiene-styrene block copolymer (SEBS), acid-modified SBS, acid-modified SEBS, styrene-isopropenyl oxazoline copolymer , Thermoplastic urethane, thermoplastic elastomer, polyamide resin, polyester resin, ε-caprolactam, ω-aminoundecanoic acid, ω-aminododecanoic acid, ω-laurolactam and the like. These may be used alone or in combination of two or more.

  Examples of the modified EGMA include those obtained by grafting polystyrene (PS), polymethyl methacrylate (PMMA), acrylonitrile-styrene copolymer (AS), a copolymer of PMMA and butyl acrylate, etc. to EGMA. It is done.

  Examples of the modified EEA include EEA grafted with a copolymer of PS, PMMA, AS, PMMA and butyl acrylate, maleic anhydride-modified EEA, silane-modified EEA, and the like.

  As the modified ethylene-ethyl acrylate-maleic anhydride copolymer, for example, a copolymer of PS, PMMA, AS, PMMA and butyl acrylate is grafted to the ethylene-ethyl acrylate-maleic anhydride copolymer. And so on.

  Examples of the modified EVA include EVA grafted with a copolymer of PS, PMMA, AS, PMMA and butyl acrylate, and the like.

  Moreover, as modified PP, what grafted PS or AS to PP, maleic anhydride modified PP, etc. are mention | raise | lifted, for example.

  In addition, as the modified PE, for example, any one of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), PS, PMMA, AS, PMMA and butyl acrylate Examples include grafted copolymers and maleic anhydride-modified PE.

  The impact resistance improver is not particularly limited. For example, ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene copolymer (EPM), hydrogenated acrylonitrile-butadiene copolymer (H- NBR) and the like, and thermoplastic elastomers and resins such as EGMA, modified EGMA, SBS, acid-modified SBS, SEBS, epoxidized SEBS, acid-modified SEBS, and polybutene. These may be used alone or in combination of two or more.

  Further, the blending ratio of the impact resistance improving material is preferably in the range of 1 to 100 parts, particularly preferably 2 to 100 parts by weight (hereinafter abbreviated as “part”) of the PAS resin as the material for the inner layer. Within the range of 80 parts.

  In the present invention, a compound material layer (adhesive layer) of PAS resin and polyamide resin may be provided on the inner peripheral surface side of the inner layer 1, and the innermost layer may be formed on the inner side. The innermost layer material is not particularly limited, and examples thereof include a modified fluororesin. In addition, the modified fluororesin may be subjected to a conductive treatment with a conductive agent such as carbon black, for example.

  Next, the intermediate layer 2 formed on the outer periphery of the inner layer 1 is not particularly limited as long as it is formed of a single layer film or a multilayer film having a chromium-based oxide film as a constituent film. For example, as shown in FIG. In addition, even a single-layer film made of a chromium-based oxide film is a multilayer film in which a metal film 4 is interposed between a chromium-based oxide film 5 and a chromium-based oxide film 5 (see FIG. 2). A chromium oxide film 5 / a metal film 4 / a chromium oxide film 5) may be used. Note that a multilayer film in which the metal film 4 is interposed between the chromium-based oxide films 5 is more preferable in that the low permeability is further improved as compared with a single-layer film made of a chromium-based oxide film.

  Further, the intermediate layer 2 is not limited to the three-layer film structure (chromium oxide film 5 / metal film 4 / chromium oxide film 5) as shown in FIG. If the side contacting the outer layer 6 is the chromium-based oxide film 5, the number of the metal films 4 interposed between them is not particularly limited. For example, a five-layer structure (chromium-based oxide film 5 / metal) Film 4 / chromium oxide film 5 / metal film 4 / chromium oxide film 5), 7 layer structure (chromium oxide film 5 / metal film 4 / chromium oxide film 5 / metal film 4 / chromium oxide film 5 / A multilayer film such as metal film 4 / chromium oxide film 5) may be used.

  Examples of the material for forming the chromium-based oxide film include chromium oxide, stainless steel (SUS) oxide, nickel-chromium oxide, and the like. Different metals other than chromium, metal oxides other than chromium-based oxides, etc. Can be used together. Next, as a material for forming a metal film interposed between the chromium-based oxide films, for example, aluminum, magnesium, iron, copper, nickel, titanium, chromium, tantalum, cobalt, palladium, gold, platinum, silver, carbon, Examples thereof include silicon, molybdenum, tungsten, selenium, tin, indium, zinc, vanadium, zircon, yttrium, and alloys thereof. These may be used alone or in combination of two or more. Among these, aluminum, nickel-chromium alloy, chromium, and stainless steel are preferable from the viewpoint of adhesion with a chromium-based oxide film and film formation speed.

  Examples of the method for forming the intermediate layer 2 include physical vapor deposition (PVD (Physical Vapor Deposition)) such as sputtering, ion plating, and vacuum vapor deposition. Among these, sputtering or ion plating is preferable from the viewpoint of adhesion. The chromium-based oxide film can be formed by reacting chromium or a chromium-containing alloy material with oxygen at the time of film formation or by using a chromium-containing oxide material to form a film by the physical vapor deposition method.

  The thickness of the intermediate layer 2 having the chromium-based oxide film as a constituent film is preferably in the range of 5 nm to 10 μm, particularly preferably in the range of 10 nm to 3 μm. That is, if the film thickness is too thin, it is difficult to form a uniform film, and low fuel permeability and interlayer adhesion tend to be inferior. Conversely, if the film thickness is too thick, the film tends to crack and economically. It will be expensive. In this case, when the intermediate layer 2 is made of a single layer film of a chromium-based oxide film, the thickness of the chromium-based oxide film is in the range of 5 nm to 10 μm. Each film thickness of the film is a value obtained by dividing the film thickness of the multilayer film by the above arbitrary number. Further, when a metal film is interposed between the chromium-based oxide films as a single layer film or a multilayer film, the film thickness is usually set in a range of 10 nm to 10 μm.

Next, as a material for the bonding layer used for forming the bonding layer 3, a material mainly composed of the following polyamide resin (A) or modified polyolefin resin is used.
(A) At least one polyamide resin selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 copolymer and polyamide 66 copolymer.

  Specific examples of the polyamide resin (A) include polyamide 6 (PA6), polyamide 66 (PA66), polyamide 6/66 (PA6 / 66) copolymer, polyamide 6/69 (PA6 / 69) copolymer, Polyamide 6/610 (PA 6/610) copolymer, polyamide 6/12 (PA 6/12) copolymer and the like can be mentioned. These may be used alone or in combination of two or more. Among these, polyamide 6 (PA6), polyamide 66 (PA66), polyamide 6/12 (PA6 / 12) copolymer is suitably used from the viewpoint of availability and economy, and is used for the outer layer 6. From the viewpoint that the terminal amino value of the aliphatic polyamide resin does not need to be specified, a polyamide 6/12 (PA 6/12) copolymer is most preferable.

  Examples of the modified polyolefin resin include those obtained by modifying a polyolefin resin with a modifying agent such as an unsaturated carboxylic acid. From the viewpoint of heat resistance, acid-modified polypropylene (PO) resin, A density polyethylene (HDPE) resin or the like is preferable.

  Examples of the polyolefin resin in the modified polyolefin resin include thermoplastic resins obtained by polymerizing or copolymerizing olefins such as ethylene, propylene, butene, isoprene, and pentene. Specific examples of the polyolefin resin include homopolymers such as polyethylene (PE), polypropylene (PP), polystyrene, polyacrylate, polymethacrylate, poly-1-butene, poly-1-pentene, and polymethylpentene. , Ethylene / α-olefin copolymer, vinyl alcohol ester homopolymer, polymer obtained by hydrolyzing at least a part of vinyl alcohol ester homopolymer, at least one of ethylene and propylene, and vinyl alcohol ester Polymer obtained by hydrolyzing at least part of copolymer, copolymer of at least one of ethylene and propylene and at least one of unsaturated carboxylic acid and unsaturated carboxylic acid ester, at least one of ethylene and propylene And unsaturated Copolymer obtained by metallizing at least a part of the carboxyl group of a copolymer with at least one of rubonic acid and unsaturated carboxylic acid ester, block copolymer of conjugated diene and vinyl aromatic hydrocarbon, conjugated diene and vinyl Examples thereof include hydrides of block copolymers with aromatic hydrocarbons. These may be used alone or in combination of two or more. Among these, polyethylene, polypropylene, an ethylene / α-olefin copolymer, a copolymer of at least one of ethylene and propylene, and at least one of an unsaturated carboxylic acid and an unsaturated carboxylic ester, at least of ethylene and propylene A copolymer in which at least a part of a carboxyl group of a copolymer of one side and at least one of an unsaturated carboxylic acid and an unsaturated carboxylic acid ester is metallated is preferable, particularly when heat resistance such as an engine room is required. High density polyethylene (HDPE), polypropylene, an ethylene / polypropylene copolymer, or a material containing these materials is preferably used for.

  Examples of the modifying agent that modifies the polyolefin resin include at least one compound of an unsaturated carboxylic acid and a derivative thereof. Examples of the unsaturated carboxylic acid or derivative thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, crotonic acid, methylmaleic acid, methyl fumaric acid, mesaconic acid, citraconic acid, glutaconic acid, and carboxylic acids thereof. Metal salts of, methyl hydrogen maleate, methyl itaconate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methacrylate, 2-ethylhexyl methacrylate, hydroxy methacrylate Ethyl, aminoethyl methacrylate, dimethyl maleate, dimethyl itaconate, maleic anhydride, itaconic anhydride, citraconic anhydride, endobicyclo- (2,2,1) -5-heptene-2,3-dicarboxylic acid, endobisic -(2,2,1) -5-heptene-2,3-dicarboxylic anhydride, maleimide, N-ethylmaleimide, N-butylmaleimide, N-phenylmaleimide, glycidyl acrylate, glycidyl methacrylate, glycidyl methacrylate Glycidyl itaconate, glycidyl citraconic acid, 5-norbornene-2,3-dicarboxylic acid and the like. These may be used alone or in combination of two or more. Of these, unsaturated dicarboxylic acids and acid anhydrides thereof are preferred, and maleic acid and maleic anhydride are particularly preferred.

  Here, the method for producing the modified polyolefin resin by introducing at least one compound of unsaturated carboxylic acid and its derivative into the polyolefin resin is not particularly limited. For example, the polyolefin resin as a main component is used. A method of copolymerizing a resin with at least one compound of an unsaturated carboxylic acid and its derivative, or grafting an unsaturated carboxylic acid and at least one compound of its derivative onto a non-modified polyolefin resin using a radical initiator And the like.

  Next, as the outer layer material used for forming the outer layer 6, an aliphatic polyamide resin is used. Although it does not specifically limit as said aliphatic polyamide resin, From points, such as calcium chloride resistance, a weather resistance, and impact resistance, polyamide 11 (PA11), polyamide 12 (PA12), polyamide 610 (PA610), polyamide 612 Examples thereof include aliphatic polyamide resins such as (PA612), and copolymers thereof with polyether (for example, polyamide 6-polyether copolymer, polyamide 12-polyether copolymer, etc.). These may be used alone or in combination of two or more.

  When the aliphatic polyamide resin uses any one of the polyamide resin (A) and the modified polyolefin resin other than the PA6 / 12 copolymer as the material of the bonding layer 3, the terminal amino group concentration is used from the viewpoint of adhesiveness. Is preferably 40 μ equivalent / g or more, and particularly preferably in the range of 50 to 80 μ equivalent / g. That is, when the terminal amino group concentration of the aliphatic polyamide resin is less than 40 μequivalent / g, adhesion to the polyamide resin (A) or the modified polyolefin resin other than the PA6 / 12 copolymer used for the bonding layer 3 is achieved. This is because there is a tendency to be inferior. When the terminal amino group concentration of the aliphatic polyamide resin exceeds 80 μequivalent / g, the molecular weight of the aliphatic polyamide resin decreases, so that the workability tends to deteriorate in terms of melt viscosity during molding. Since the physical properties of the molded product tend to deteriorate, the aliphatic polyamide resin preferably has a terminal amino group concentration in the range of 40 to 80 μeq / g.

  In addition, when PA6 / PA12 copolymer is used as the material of the bonding layer 3, the interlayer adhesive strength between the outer layer 6 and the aliphatic polyamide resin is 20 N / cm or more regardless of the terminal amino group concentration ( Because the PA12 component of the PA6 / PA12 copolymer of the bonding layer 3 contributes to interlayer adhesion with the outer layer 6), the terminal amino group concentration of the aliphatic polyamide resin of the outer layer 6 may not be specified.

  Here, the terminal amino group concentration of the aliphatic polyamide resin can be measured, for example, as follows. That is, a predetermined amount of polyamide-based resin is put into a conical flask with a stopcock, 40 ml of a previously prepared solvent [phenol / methanol = 9/1 (volume ratio)] is added, and the mixture is stirred and dissolved with a magnetic stirrer. It can be determined by titrating with 0.05 N hydrochloric acid using thymol blue.

  In addition to the aliphatic polyamide resin, the outer layer material requires carbon black, process oil, anti-aging agent, processing aid, crosslinking accelerator, white filler, reactive monomer, foaming agent, etc. Depending on the case, it may be appropriately blended.

  Here, the low-permeability resin hose of the present invention as shown in FIG. 1 can be produced, for example, as follows. That is, as described above, the inner layer material, the intermediate layer material, the bonding layer material, and the outer layer material are prepared. Next, the inner layer material is extruded into a hose shape to form a tubular inner layer 1. At this time, a mandrel may be used, and a compound material layer (adhesive layer) of PAS resin and polyamide resin is provided on the inner peripheral surface side of the inner layer 1 or an innermost layer is formed on the inner side thereof. There is no problem. Next, the intermediate layer 2 is formed on the surface of the inner layer 1 by sputtering using a DC magnetron sputtering apparatus. Next, the bonding layer material and the outer layer material are co-extruded in the form of a hose on the surface of the intermediate layer 2 to sequentially form the bonding layer and the outer layer. In this manner, a low-permeability resin hose having a multilayer structure in which the intermediate layer 2 is formed on the outer peripheral surface of the inner layer 1, the bonding layer 3 is formed on the outer peripheral surface, and the outer layer 6 is further formed on the outer peripheral surface. can do.

  Before the formation of the intermediate layer 2, the surface of the inner layer 1 may be subjected to an etching process such as an ultraviolet irradiation process, a plasma process, or a corona discharge process as an adhesive base process. Among these, it is preferable to plasma-treat the outer peripheral surface of the inner layer 1 and directly form the intermediate layer 2 on the plasma-treated surface in terms of improving interlayer adhesion.

  The plasma treatment conditions are as follows: the reaction pressure is 1 to 300 Pa, the gas types are Ar, N2, O2, He, Ne, H2, the output is 0 to 6 kW, the treatment time is 1 second to 20 minutes, and the oscillation output is 13 56 MHz (due to legal restrictions) ± 0.05% (due to manufacturer specifications) is preferable.

  In the low-permeability resin hose of the present invention, the inner diameter of the hose is preferably in the range of 2 to 40 mm, particularly preferably in the range of 2.5 to 36 mm, and the outer diameter of the hose is preferably in the range of 3 to 44 mm, particularly preferably. Is in the range of 4-40 mm. The thickness of the inner layer 1 is preferably in the range of 0.02 to 1.0 mm, particularly preferably in the range of 0.05 to 1.0 mm. Moreover, the thickness of the outer layer 2 is usually in the range of 0.2 to 1.5 mm, and preferably in the range of 0.3 to 1.0 mm.

  Note that the low-permeability resin hose of the present invention is not limited to the four-layer structure as shown in FIG. 1 or the six-layer structure as shown in FIG. 2. For example, as described above, the inner layer The innermost layer may be formed on the inner peripheral surface side of one, and other layers may be formed on the outer peripheral surface side of the outer layer 6. In some cases, an adhesive layer may be provided between the layers.

  The low-permeability resin hose of the present invention is used in automobiles and transportation equipment (industrial transport vehicles such as airplanes, forklifts, excavators, cranes, railway vehicles, etc.), etc., gasoline, alcohol-mixed gasoline (gasohol), alcohol, hydrogen , Diesel oil, dimethyl ether, diesel, CNG (compressed natural gas), LPG (liquefied petroleum gas) and other fuel transportation hoses, or chlorofluorocarbon, alternative chlorofluorocarbon, water, carbon dioxide and other refrigerant transportation hoses used for air conditioners and radiators It is used suitably for etc.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

  First, prior to the examples and comparative examples, the following materials were prepared.

[PO-1 (bonding layer material)]
Maleic anhydride-modified HDPE (manufactured by Nippon Polyolefin Co., Ltd., Adtex DH0200)

[PO-2 (material for bonding layer)]
Maleic anhydride modified PP (Mitsui Chemicals, Admer QF551)

[PA-1 (material for bonding layer)]
PA6 (Ube Industries, UBE nylon 1022B)

[PA-2 (bonding layer material)]
PA6 / 12 copolymer (manufactured by Ube Industries, UBE nylon 7034B)

[PA-3 (material for outer layer)]
PA12 (manufactured by EMS, Grillamide L25ANZ, terminal amino group concentration: 63 μeq / g)

[PA-4 (material for outer layer)]
PA12 (Ube Industries, Uvesta 3030JLX2, terminal amino group concentration: 31 μeq / g)

[Example 1]
PPS resin (Torayna A670X01 manufactured by Toray Industries, Inc.) was extruded into a hose shape to form a tubular inner layer (thickness 0.1 mm). Next, on the outer peripheral surface of the inner layer, using a high-frequency plasma device manufactured in-house, a plasma is produced under the conditions of reaction pressure: 67 Pa, gas type: Ar, output: 200 W, processing time: 20 seconds, oscillation output: 13.56 MHz. Processed. Next, an intermediate layer (thickness 0.1 μm) made of a Ni—Cr oxide film was formed on the plasma-treated surface by sputtering under the conditions shown in Table 4 below using a DC magnetron sputtering apparatus. Next, on the surface of the intermediate layer, a PA6 resin as a material for a bonding layer and a polyamide 12 resin as a material for an outer layer are coextruded in a hose shape, and a bonding layer (thickness 0.2 mm) and an outer layer are sequentially formed. Formed. In this way, a low-permeability resin hose (inner diameter 33 mm, outer diameter 36 mm) having a structure in which an intermediate layer made of a Ni—Cr oxide film, a bonding layer, and an outer layer were sequentially formed on the outer peripheral surface of the inner layer was produced.

[Examples 2 to 7]
As shown in Table 1 below, a low-permeability resin hose (according to Example 1) except that the intermediate layer forming material, film forming conditions (see Table 4) or the bonding layer material and the outer layer material are changed. An inner diameter of 33 mm and an outer diameter of 36 mm) were produced.

[Examples 8 to 14]
As shown in Table 2 below, except that the intermediate layer forming material, film forming conditions (see Table 4) or the bonding layer material and the outer layer material are changed, and the outer peripheral surface of the inner layer is not subjected to plasma treatment. In accordance with Example 1, a low-permeability resin hose (inner diameter: 33 mm, outer diameter: 36 mm) was produced.

[Comparative Examples 1-4]
As shown in Table 3 below, the intermediate layer forming material, film forming conditions (see Table 4) or the outer layer material are changed, the bonding layer is not formed, and the outer peripheral surface of the inner layer is not subjected to plasma treatment. Except for the above, a low-permeability resin hose (inner diameter: 33 mm, outer diameter: 36 mm) was prepared according to Example 1.

[Comparative Example 5]
A resin hose (inner diameter: 33 mm, outer diameter: 36 mm) was prepared according to Example 14 except that the intermediate layer was not formed.

  Using the low-permeability resin hoses of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are shown in Tables 1 to 3 below.

[Transmission coefficient]
The CARB SHED method cannot measure the amount of gasohole permeation through a very low-permeability hose due to measurement limitations. Then, after cutting each low-permeability resin hose of an Example and a comparative example in the longitudinal direction, it punched in the disk shape of diameter 56mm and produced each sample. And the simulated alcohol which mixed toluene / isooctane / ethanol in the ratio of 45:45:10 (volume ratio) in the above-mentioned sample using a differential pressure type and vapor permeability measuring device (GTR-30XATG made by GTR Tech). The permeability coefficient of the added gasoline was measured at 40 ° C. for 2 weeks. In addition, the transmission coefficient (mg · mm / cm ² / day) in the table indicates a value after 2 weeks.

(Interlayer adhesion)
Each low-permeability resin hose was cut into a strip shape with a width of 10 mm to prepare a sample. The inner layer / outer layer of each sample was peeled and sandwiched between chucks of a tensile tester, and the 180 ° peel strength (N / cm) was measured under the condition of a tensile speed of 50 mm / min. Moreover, when peeling, the peeling location was described in the table | surface. If the peel strength is 20 N / cm or more, it is considered that the interlayer adhesion is good.

  From the above results, all of the products of the examples formed a bonding layer using a specific polyamide resin (A) or a modified polyolefin-based resin as a main component, and between the inner layer and the bonding layer, The intermediate layer consisting of a single-layer film or multilayer film composed of a chromium-based oxide film is formed, so it is extremely excellent in gasoline low permeability and does not use an adhesive. Was also significantly better.

  On the other hand, the product of Comparative Example 1 has a tie layer formed between the intermediate layer and the outer layer using a tie layer material mainly composed of a specific polyamide resin (A) or a modified polyolefin resin. Therefore, although the gasoline low permeability was slightly inferior to that of the example product, it was at a level of no problem in practical use. Since Comparative Examples 2 to 4 used an oxide film other than chromium, the interlayer adhesion between the intermediate layer and the inner layer or the outer layer was inferior, and the gasoline low permeability was also inferior. In the product of Comparative Example 5, the inner layer and the bonding layer did not adhere to each other.

  The low-permeability resin hose of the present invention is a fuel such as gasoline, alcohol-mixed gasoline (gasohol), alcohol, hydrogen, light oil, dimethyl ether, diesel, CNG (compressed natural gas), LPG (liquefied petroleum gas), etc. It can be suitably used for transport hoses, or refrigerant transport hoses such as chlorofluorocarbons, alternative chlorofluorocarbons, water and carbon dioxide used in air conditioners and radiators.

It is a schematic diagram which shows an example of the low-permeability resin hose of this invention. It is a schematic diagram which shows the other example of the low-permeability resin hose of this invention.

Explanation of symbols

1 Inner layer 2 Intermediate layer 3 Bonded layer 6 Outer layer

Claims (5)

A low-permeability resin hose in which an intermediate layer, a bonding layer, and an outer layer are sequentially formed on the outer periphery of a tubular inner layer, wherein the inner layer is formed using an inner layer material mainly composed of polyarylene sulfide resin. In addition, the intermediate layer is composed of a single layer film or a multilayer film having a chromium-based oxide film as a constituent film, and the binding layer is composed of the following polyamide resin (A) or modified polyolefin-based resin as a main component. And the outer layer is formed using an outer layer material mainly composed of an aliphatic polyamide resin.
(A) At least one polyamide resin selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 copolymer and polyamide 66 copolymer.   The low-permeability resin hose according to claim 1, wherein the outer peripheral surface of the inner layer is plasma-treated, and the intermediate layer is directly formed on the plasma-treated surface.   The low-permeability resin hose according to claim 1 or 2, which is a hose for automobile fuel transportation or a hose for refrigerant transportation. Chromium-based oxidation is performed on the outer periphery of the inner layer formed of the inner layer material mainly composed of polyarylene sulfide resin by at least one physical vapor deposition method selected from the group consisting of sputtering, ion plating and vacuum vapor deposition. After forming an intermediate layer composed of a single layer film or a multilayer film having a film as a constituent film, a material for a bonding layer mainly composed of the following polyamide resin (A) or modified polyolefin resin is used on the surface of the intermediate layer. A method for producing a low-permeability resin hose comprising forming a bonding layer and forming an outer layer on the outer peripheral surface of the bonding layer using an outer layer material mainly composed of an aliphatic polyamide resin.
(A) At least one polyamide resin selected from the group consisting of polyamide 6, polyamide 66, polyamide 6 copolymer and polyamide 66 copolymer.   The method for producing a low-permeability resin hose according to claim 4, further comprising a step of plasma-treating the outer peripheral surface of the inner layer.

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