Refrigerant delivery hose and method of manufacturing the same

Abstract

Provided is a refrigerant delivery hose that is excellent in flexibility, water vapor barrier property, and heat resistance. A refrigerant delivery hose (1) comprises an outer layer (4), a reinforcing layer (3), and an inner layer (2), characterized in that the outer layer is composed of a resin composition containing 100 parts by mass of an elastomer having a polyisobutylene skeleton, 10 to 150 parts by mass of a crosslinking resin, and 2.5 to 25 parts by mass of a crosslinking agent for the elastomer having a polyisobutylene skeleton, and the water vapor permeability of the resin composition constituting the outer layer is 3.0 g·mm / (m 2 ·24h) or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a refrigerant delivery hose and a method for manufacturing the same. More specifically, the present application relates to a refrigerant delivery hose for use in an air conditioner of an automobile and a method for manufacturing the same. BACKGROUND

[0002] In the process of increasing the demand for weight reduction of automobiles, there is a measure in which a resin having high barrier properties is used instead of rubber to manufacture a rubber-made hose that has been used in automobiles and to make the hose thin-walled, thereby achieving weight reduction. In particular, the main material of a refrigerant delivery hose of a conventional air conditioner of an automobile is rubber, and if the main material can be replaced with a resin having high barrier properties, weight reduction can be achieved.

[0003] Japanese Patent Application Publication No. 4-145284 (Patent Literature 1) describes a hose for delivering a refrigerant such as Freon gas, in which an outer tube is formed of a thermoplastic elastomer composed of a thermoplastic polyolefin resin and EPDM or butyl rubber.

[0004] PRIOR ART DOCUMENTS

[0005] Patent Literature 1: Japanese Patent Application Publication No. 4-145284 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] An air conditioner of an automobile or the like is mounted in a limited narrow space in an automobile, and thus a refrigerant delivery hose is required to have excellent flexibility and to be easily installed even in a narrow space. In addition, the permeation of water vapor from the outside of the hose becomes a cause of the freezing of moisture inside the air conditioner, and thus the material forming the outer tube of the refrigerant delivery hose is required to have excellent water vapor barrier properties. Furthermore, durability that enables long-term use in a high-temperature and high-humidity environment in an engine compartment is also required.

[0008] However, the outer tube of the resin hose described in Patent Literature 1 is formed of a thermoplastic elastomer containing a thermoplastic polyolefin resin, and thus the heat resistance is not necessarily sufficient.

[0009] The present application relates to a refrigerant delivery hose and a method for manufacturing the same. More specifically, the present application relates to a refrigerant delivery hose for use in an air conditioner of an automobile and a method for manufacturing the same.

[0010] MEANS FOR SOLVING THE PROBLEMS

[0011] The present application (I) relates to a refrigerant delivery hose comprising an outer layer, a reinforcing layer, and an inner layer, characterized in that the outer layer is composed of a resin composition containing 100 parts by mass of an elastomer having a polyisobutylene skeleton, 10 to 150 parts by mass of a crosslinking resin, and 2.5 to 25 parts by mass of a crosslinking agent for the elastomer having a polyisobutylene skeleton, and the water vapor permeability of the resin composition constituting the outer layer is 3.0 g·mm / (m 2 ·24h) or less.

[0012] The present application (II) relates to a method for producing the refrigerant delivery hose of the present application (I), characterized in that the method comprises a step of kneading an elastomer having a polyisobutylene skeleton, a crosslinking resin, and a crosslinking agent for the elastomer having a polyisobutylene skeleton to prepare an outer layer composition, and a step of adding a silanol condensation catalyst to the outer layer composition at the time of extrusion molding of the hose, and extrusion molding the composition to which the silanol condensation catalyst has been added to form the outer layer.

[0013] The present application includes the following technical solutions.

[0014] [1] A refrigerant delivery hose comprising an outer layer, a reinforcing layer, and an inner layer, the outer layer being composed of a resin composition containing 100 parts by mass of an elastomer having a polyisobutylene skeleton, 10 to 150 parts by mass of a crosslinking resin, and 2.5 to 25 parts by mass of a crosslinking agent for the elastomer having a polyisobutylene skeleton, and the water vapor permeability of the resin composition constituting the outer layer being 3.0 g·mm / (m 2 ·24h) or less.

[0015] [2] The refrigerant delivery hose according to [1], the crosslinking agent for the elastomer having a polyisobutylene skeleton containing zinc white and an alkylphenol formaldehyde resin.

[0016] [3] The refrigerant delivery hose according to [1] or [2], the content of zinc white in the resin composition constituting the outer layer being 1 to 10 parts by mass based on 100 parts by mass of the elastomer having a polyisobutylene skeleton, and the content of the alkylphenol formaldehyde resin being 1.5 to 15 parts by mass based on 100 parts by mass of the elastomer having a polyisobutylene skeleton.

[0017] [4] The refrigerant delivery hose according to any one of [1] to [3], the elastomer having a polyisobutylene skeleton in the resin composition constituting the outer layer being butyl rubber or modified butyl rubber, and the elastomer having a polyisobutylene skeleton being dynamically crosslinked.

[0018] [5] The refrigerant delivery hose according to any one of [1] to [4], wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked with a silane-modified resin obtained by modifying a thermoplastic resin with a silane compound.

[0019] [6] The refrigerant delivery hose according to any one of [1] to [5], wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked with a silane-modified polyolefin obtained by modifying a polyolefin with a silane compound.

[0020] [7] The refrigerant delivery hose according to any one of [1] to [6], wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked with a silane-modified polypropylene obtained by modifying a polypropylene with a silane compound.

[0021] [8] The refrigerant delivery hose according to any one of [1] to [7], wherein the resin composition constituting the outer layer contains 1 to 10 parts by mass of an anti-aging agent, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton.

[0022] [9] The refrigerant delivery hose according to any one of [1] to [8], wherein the resin composition constituting the outer layer has a breaking strength TB 150 of 1.0 MPa or more at 150°C.

[0023]

[10] The refrigerant delivery hose according to any one of [1] to [9], wherein the resin composition constituting the outer layer contains a base containing a crosslinked resin and a domain containing an elastomer having a polyisobutylene skeleton dispersed in the base, and the base is crosslinked.

[0024]

[11] The refrigerant delivery hose according to any one of [1] to

[10] , wherein the resin composition constituting the outer layer contains a base containing a crosslinked resin and a domain containing an elastomer having a polyisobutylene skeleton dispersed in the base, and the domain is crosslinked.

[0025]

[12] The refrigerant delivery hose according to any one of [1] to

[11] , wherein the inner layer is constituted by a thermoplastic resin composition containing 100 parts by mass of an elastomer and 30 to 170 parts by mass of a thermoplastic resin, the thermoplastic resin composition has an island-in-sea structure in which the elastomer is present as a domain in a base containing the thermoplastic resin, the thermoplastic resin contains 50 to 100 parts by mass of a polyamide, based on 100 parts by mass of the thermoplastic resin, the elastomer contains an elastomer having a polyisobutylene skeleton, and the thermoplastic resin composition further contains a processing aid and an anti-aging agent of a phenylenediamine type or a quinoline type.

[0026]

[13] A method of producing the refrigerant delivery hose described in any one of [1] to

[12] , the method comprising: a step of kneading an elastomer having a polyisobutylene skeleton, a cross-linkable resin, and a cross-linking agent for the elastomer having a polyisobutylene skeleton to prepare an outer layer composition, and a step of adding a silanol condensation catalyst to the outer layer composition at the time of extrusion molding of the hose, and extrusion molding the composition to which the silanol condensation catalyst has been added to form an outer layer.

[0027]

[14] The method described in

[13] , comprising, after the step of forming the outer layer, a step of contacting the outer layer with water or water vapor to cross-link the base resin in the resin composition constituting the outer layer.

[0028] Effects of the Invention

[0029] The refrigerant delivery hose of the present application is excellent in flexibility, water vapor barrier property, and heat resistance. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a cross-sectional view of a refrigerant delivery hose.

[0031] Figure 2 is a graph showing a method of evaluating the flexibility of a hose. DETAILED DESCRIPTION

[0032] The present application (I) relates to a refrigerant delivery hose.

[0033] The refrigerant delivery hose refers to a hose for delivering a refrigerant for air conditioning or the like. The refrigerant delivery hose of the present application is particularly suitable as a hose for delivering a refrigerant for automotive air conditioning. As the refrigerant for air conditioning, there can be mentioned a hydrofluorocarbon (HFC), a hydrofluoroolefin (HFO), a hydrocarbon, carbon dioxide, ammonia, water, or the like, as the HFC, there can be mentioned R410A, R32, R404A, R407C, R507A, R134a, or the like, as the HFO, there can be mentioned R1234yf, R1234ze, 1233zd, R1123, R1224yd, R1336mzz, or the like, and as the hydrocarbon, there can be mentioned methane, ethane, propane, propylene, butane, isobutane, hexafluoropropane, pentane, or the like.

[0034] The refrigerant delivery hose of the present application comprises an outer layer, a reinforcing layer, and an inner layer.

[0035] A cross-sectional view of one embodiment of the refrigerant delivery hose of the present application is shown in Figure 1 However, the present application is not limited to Figure 1 as shown in the drawing.

[0036] The refrigerant delivery hose 1 comprises an inner layer 2, a reinforcing layer 3 disposed on the outer side of the inner layer 2, and an outer layer 4 disposed on the outer side of the reinforcing layer 3.

[0037] The outer layer is composed of a resin composition containing 100 parts by mass of an elastomer having a polyisobutylene skeleton, 10 to 150 parts by mass of a crosslinking resin, and 2.5 to 25 parts by mass of a crosslinking agent for an elastomer having a polyisobutylene skeleton.

[0038] The elastomer having a polyisobutylene skeleton is not limited as long as it has a polyisobutylene skeleton, and is preferably butyl rubber (IIR), modified butyl rubber, styrene-isobutylene-styrene block copolymer, and more preferably butyl rubber or modified butyl rubber.

[0039] The polyisobutylene skeleton refers to a chemical structure formed by polymerization of a plurality of isobutylene, i.e., a chemical structure represented by -[-CH2-C(CH3)2-] n (wherein n is an integer of 2 or more).

[0040] Butyl rubber refers to an isobutylene-isoprene copolymer obtained by copolymerization of isobutylene and a small amount of isoprene, and is abbreviated as IIR.

[0041] Modified butyl rubber refers to butyl rubber in which a double bond and halogen or the like are present in the isoprene skeleton. The modified butyl rubber is preferably halogenated butyl rubber, and more preferably brominated butyl rubber, chlorinated butyl rubber, and further preferably brominated butyl rubber.

[0042] Styrene-isobutylene-styrene block copolymer is abbreviated as SIBS.

[0043] By including the elastomer having a polyisobutylene skeleton in the resin composition, the softness and water vapor barrier property of the resin composition are improved.

[0044] The elastomer having a polyisobutylene skeleton is preferably dynamically crosslinked. By being dynamically crosslinked, the durability is improved.

[0045] The resin composition constituting the outer layer contains a crosslinking resin. By containing the crosslinking resin, the resin composition is excellent in heat resistance.

[0046] The crosslinking resin refers to a crosslinked resin. The crosslinking resin is not limited, but is preferably a crosslinking resin crosslinked from a silane-modified resin. The silane-modified resin refers to a resin obtained by modifying a thermoplastic resin with a silane compound. The silane-modified resin is preferably a crosslinkable resin having a hydrolyzable silyl group (preferably an alkoxy silyl group) obtained by modifying a polyolefin-based thermoplastic resin with a silane compound, and more preferably a crosslinkable resin having a hydrolyzable silyl group (preferably an alkoxy silyl group) obtained by modifying a polyolefin-based thermoplastic resin with a silane compound.

[0047] That is, the crosslinked resin is preferably a resin crosslinked from a silane-modified resin obtained by modifying a thermoplastic resin with a silane compound, more preferably a resin crosslinked from a silane-modified polyolefin obtained by modifying a polyolefin with a silane compound, and further preferably a resin crosslinked from a silane-modified polypropylene obtained by modifying a polypropylene with a silane compound.

[0048] The silane compound is not limited, and is preferably a compound represented by formula (1).

[0049] R 1 -SiR 2 n Y 3-n (1)

[0050] wherein R 1 is an ethylenic (ethylenic) unsaturated hydrocarbon group, R 2 is a hydrocarbon group, Y is a hydrolyzable organic group, and n is an integer of 0 to 2.

[0051] R 1 is preferably an ethylenic unsaturated hydrocarbon group having 2 to 10 carbon atoms, and examples thereof include a vinyl group, a propenyl group, a butenyl group, a cyclohexenyl group, a γ-(meth)acryloyloxypropyl group, and the like.

[0052] R 2 is preferably a hydrocarbon group having 1 to 10 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, a decyl group, a phenyl group, and the like.

[0053] Y is preferably a hydrolyzable organic group having 1 to 10 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a formyloxy group, an acetyloxy group, a propionyloxy group, an alkylamino group, an arylamino group, and the like.

[0054] As specific examples of the silane compound, for example, a vinyltrimethoxysilane, a vinyltriethoxysilane, a vinyltriacetoxysilane, a γ-methacryloyloxypropyltrimethoxysilane, and the like can be given, of which a vinyltrimethoxysilane is preferred.

[0055] As the polyolefin-based thermoplastic resin constituting the silane-modified resin, there are no limitations, and examples thereof include a polyethylene, a copolymer of ethylene and an α-olefin, a polypropylene, a copolymer of propylene and another α-olefin, and the like. A polypropylene, a copolymer of propylene and another α-olefin are preferred, and a polypropylene is particularly preferred.

[0056] The hydrolyzable silyl group refers to a group that generates a silanol group (≡Si-OH) by hydrolysis, and is preferably a group represented by formula (2).

[0057] -SiR 2 n Y 3-n (2)

[0058] wherein R 2 and Y are as described above.

[0059] The cross-linkable resin refers to a resin that is capable of undergoing a cross-linking reaction but has not yet been cross-linked. The type of cross-linking reaction is not limited, and can be cross-linking using a peroxide, or preferably cross-linking using moisture (hydro-cross-linking).

[0060] The method of modification with the silane compound is not limited, and grafting or copolymerization can be cited. Grafting is a method of adding a silane compound to a resin through a grafting reaction, and more specifically, is a reaction in which carbon radicals are generated by cleavage of carbon-hydrogen bonds of a polyolefin, and a silane compound having an olefinically unsaturated hydrocarbon group is added thereto. The modification is preferably performed by melt-kneading the resin and the silane compound of formula (1) in the presence of a radical initiator such as an organic peroxide. The copolymerization is preferably performed by radical copolymerization of a monomer constituting the resin and the silane compound of formula (1).

[0061] The silane-modified resin is preferably a silane-modified polypropylene. The silane-modified resin used in the present application can use a commercially available product. As a commercially available product of the silane-modified resin, "Linklon" (registered trademark) manufactured by Mitsubishi Chemical Corporation can be cited.

[0062] The content of the cross-linking resin is 10 to 150 parts by mass, preferably 10 to 100 parts by mass, and more preferably 10 to 80 parts by mass, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton. If the content of the cross-linking resin is too small, the extrusion processability deteriorates, and if it is too large, softness cannot be ensured.

[0063] The resin composition constituting the outer layer can contain a resin other than the cross-linking resin.

[0064] As the resin other than the cross-linking resin, a polyolefin resin, a polyamide resin, or the like can be cited. As the polyolefin resin, polypropylene can be cited. By containing polypropylene on the basis of the silane-modified resin, the viscosity of the resin component stabilizes, and thus a phase structure that easily exhibits heat strength is obtained. In addition, since the water vapor barrier property of polypropylene is good, the water vapor barrier property of the entire composition is good.

[0065] The resin composition constituting the outer layer contains a cross-linking agent of an elastomer having a polyisobutylene skeleton. Hereinafter, the "cross-linking agent of an elastomer having a polyisobutylene skeleton" will also be simply referred to as a "cross-linking agent". The resin composition has improved heat resistance after cross-linking (after dynamic cross-linking) by containing the cross-linking agent.

[0066] The cross-linking agent preferably contains zinc white and an alkylphenol formaldehyde resin. By containing zinc white and an alkylphenol formaldehyde resin, the cross-linking agent can impart heat resistance to the resin composition after cross-linking (after dynamic cross-linking) of 150°C in an environment.

[0067] Zinc white refers to zinc oxide, which is an oxide of zinc represented by the chemical formula ZnO. Zinc white is commercially available, and commercially available products can be used in the present application. As examples of commercially available products, there are three kinds of zinc oxide manufactured by Shachi Chemical Industry Co., Ltd.

[0068] The alkylphenol formaldehyde resin refers to a compound represented by formula (3).

[0069]

[0070] In formula (3), X is a hydroxyl group or a halogen, Y and Y' are hydrogen or an alkyl group, Z is an alkyl group or a halogen, and n is an integer of 0 to 20. The halogen constituting X and Z is preferably fluorine, chlorine, bromine, or iodine, and more preferably bromine. The alkyl group constituting Y, Y', and Z is preferably an alkyl group having 1 to 8 carbon atoms.

[0071] The structural formula represented by formula (3) is a straight chain, but the alkylphenol formaldehyde resin can have a branched portion synthesized according to a conventional method.

[0072] In addition, when X is bromine, it is referred to as a brominated alkylphenol formaldehyde resin.

[0073] The alkylphenol formaldehyde resin is commercially available, and commercially available products can be used in the present application. As examples of commercially available products, there is an alkylphenol-formaldehyde resin "Hitanol" (registered trademark) 2501Y manufactured by Hitachi Chemical Co., Ltd.

[0074] The content of the cross-linking agent is 2.5 to 25 parts by mass, preferably 2.5 to 20 parts by mass, and more preferably 2.5 to 18 parts by mass, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton. If the content of the cross-linking agent is too small, the dynamic cross-linking of the elastomer is insufficient, and the hot time strength decreases. If it is too large, the silane cross-linking of the resin is hindered, and the hot time strength decreases.

[0075] The content of the zinc white is 1 to 10 parts by mass, preferably 2 to 8 parts by mass, and more preferably 3 to 8 parts by mass, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton. If the content of the zinc white is too small, the dynamic cross-linking of the elastomer is insufficient, and the hot time strength decreases. If it is too large, the silane cross-linking of the resin is hindered, and the hot time strength decreases.

[0076] The content of the alkylphenol formaldehyde resin is 1.5 to 15 parts by mass, preferably 1.5 to 10 parts by mass, and more preferably 2 to 10 parts by mass, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton. If the content of the alkylphenol formaldehyde resin is too small, the dynamic crosslinking of the elastomer is insufficient, and the hot strength decreases. If it is too large, the silane crosslinking of the resin is hindered, and the hot strength decreases.

[0077] The resin composition constituting the outer layer preferably contains a silanol condensation catalyst. By containing the silanol condensation catalyst, the crosslinking of the silane-modified resin is promoted at the time of forming the crosslinked resin.

[0078] As the silanol condensation catalyst, there are no particular limitations, and metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids, organic acids, inorganic acid esters, and the like can be given.

[0079] As the metal organic acid salt, there are no particular limitations, and dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, stannous acetate, stannous octoate, cobalt naphthenate, lead octoate, lead naphthenate, zinc octanoate, zinc caprylic acid, iron 2-ethylhexanoate, iron octoate, iron stearate, and the like can be given.

[0080] As the titanate, there are no particular limitations, and tetrabutyl titanate, tetrapropyl titanate, bis(acetylacetone)diisopropyl titanate, and the like can be given.

[0081] As the organic amine, there are no particular limitations, and ethylamine, dibutylamine, hexylamine, triethanolamine, dimethylsoybean amine, tetramethylguanidine, pyridine, and the like can be given.

[0082] As the ammonium salt, there are no particular limitations, and ammonium carbonate, tetramethylammonium hydroxide, and the like can be given.

[0083] As the phosphonium salt, there are no particular limitations, and tetramethylphosphonium hydroxide and the like can be given.

[0084] As the inorganic acid, there are no particular limitations, and sulfuric acid, hydrochloric acid, and the like can be given.

[0085] As the organic acid, there are no particular limitations, and sulfonic acids such as acetic acid, stearic acid, maleic acid, toluenesulfonic acid, alkyl naphthalene sulfonic acid, and the like can be given. As the inorganic acid ester, there are no particular limitations, and phosphoric acid esters and the like can be given.

[0086] The silanol condensation catalyst is preferably a metal organic acid salt, a sulfonic acid, a phosphoric acid ester, and more preferably a metal carboxylate of tin such as dioctyltin dilaurate, an alkyl naphthalene sulfonic acid, and ethylhexyl phosphoric acid ester. In addition, the silanol condensation catalyst can be used alone or in combination of two or more.

[0087] The content of the silanol condensation catalyst is not particularly limited, and is preferably 0.0001 to 0.5 parts by mass, more preferably 0.0001 to 0.3 parts by mass, based on 100 parts by mass of the silane-modified resin.

[0088] In addition, the silanol condensation catalyst is preferably used as a master batch of a silanol condensation catalyst in which a resin and the silanol condensation catalyst are compounded. As the resin that can be used in the master batch of the silanol condensation catalyst, polyolefins and the like can be given, and polyethylene, polypropylene, copolymers thereof, and the like are preferred.

[0089] In the case where the silanol condensation catalyst is used as a master batch of a silanol condensation catalyst in which a resin and the silanol condensation catalyst are compounded, the content of the silanol condensation catalyst in the master batch is not particularly limited, and is preferably 0.1 to 5.0% by mass. In addition, the master batch of the silanol condensation catalyst can be a commercially available product, and for example, "PZ010" manufactured by Mitsubishi Chemical Corporation can be used.

[0090] The resin composition constituting the outer layer preferably contains an anti-aging agent. By containing the anti-aging agent, the extrusion moldability at the time of molding the resin composition before crosslinking is excellent.

[0091] As the anti-aging agent, there is no particular limitation, and hindered phenol-based antioxidants, phenol-based antioxidants, amine-based antioxidants, phosphorus-based heat stabilizers, metal deactivators, sulfur-based heat-resistant stabilizers, and the like can be given, and hindered phenol-based antioxidants are preferred, and hindered phenol-based antioxidants containing a pentaerythritol ester structure are more preferred. As specific examples of the hindered phenol-based antioxidants, IRGANOX (registered trademark) 1010 (pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]) manufactured by BASF Japan Ltd. can be given.

[0092] The content of the anti-aging agent is preferably 1 to 10 parts by mass, more preferably 2 to 8 parts by mass, and more preferably 3 to 7 parts by mass, based on 100 parts by mass of the elastomer having a polyisobutylene skeleton.

[0093] The resin composition constituting the outer layer can contain an elastomer other than the elastomer having a polyisobutylene skeleton, a resin other than the crosslinking resin, a silanol condensation catalyst, and an additive other than the anti-aging agent, within a range that does not hinder the effects of the present application.

[0094] The resin composition constituting the outer layer can have any phase structure, and preferably has a sea-island structure or a co-continuous structure, and more preferably has a sea-island structure composed of a matrix (sea phase) containing a crosslinking resin and a domain (island phase) containing an elastomer having a polyisobutylene skeleton dispersed in the matrix.

[0095] The matrix is preferably crosslinked. The crosslinking of the matrix contributes to heat resistance.

[0096] The domains are preferably cross-linked. Cross-linking of the domains contributes to heat resistance.

[0097] More preferably, both the matrix and the structural domain are cross-linked.

[0098] If it is a co-continuous structure, it has excellent flexibility.

[0099] The water vapor permeability of the resin composition constituting the outer layer is 3.0 g·mm / (m 2 ·24h) or less, preferably 2.5 g·mm / (m 2 ·24h or less, more preferably 2.0 g·mm / (m 2 ·24h and below.

[0100] If the water vapor permeability is too high, moisture from the outside air will seep into the refrigerant delivery hoses, causing moisture to freeze inside the air conditioner. This invention effectively blocks the intrusion of external moisture by using a material that is impermeable to water vapor in the outer layer.

[0101] The water vapor transmission coefficient is defined as follows. The water vapor transmission coefficient is the percentage of water vapor transmitted per meter of surface area under specified temperature and humidity conditions. 2 The amount of water vapor that can pass through an area with a thickness of 1 mm over 24 hours.

[0102] The water vapor transmission rate was measured using a water vapor transmission tester at a temperature of 60°C and a relative humidity of 95%.

[0103] The rupture strength (TB) of the resin composition constituting the outer layer at 150°C 150 Preferably, the strength is 1.0 MPa or higher, more preferably 1.2 to 30 MPa, and even more preferably 1.5 to 25 MPa. This is to improve the tensile strength TB of the resin composition at 150°C. 150 Within the above numerical range, the degree of crosslinking of the rubber is important.

[0104] The breaking strength can be determined based on the test method specified in JIS K6251 "Vulcanized rubber and thermoplastic rubber - Determination of tensile properties".

[0105] There are no restrictions on the reinforcing layer; for example, it can be a woven fiber layer.

[0106] There are no restrictions on the reinforcing layer, but it is preferred to contain polyester fiber, polyamide fiber, aramid fiber, PBO fiber, vinylon fiber or rayon fiber.

[0107] The inner layer is not limited, and is preferably formed of a thermoplastic resin composition containing 100 parts by mass of an elastomer and 30 to 170 parts by mass of a thermoplastic resin, the thermoplastic resin composition having an island-in-sea structure in which the elastomer exists as a domain in a matrix containing the thermoplastic resin, the thermoplastic resin containing 50 to 100 parts by mass of a polyamide based on 100 parts by mass of the thermoplastic resin, and the elastomer including an elastomer having a polyisobutylene skeleton, and the thermoplastic resin composition further including a phenylenediamine-based or quinoline-based anti-aging agent and a processing aid.

[0108] The thermoplastic resin constituting the inner layer is not limited, and preferably contains 50 to 100 parts by mass of a polyamide based on 100 parts by mass of the thermoplastic resin, more preferably 75 to 100 parts by mass of a polyamide based on 100 parts by mass of the thermoplastic resin, and further preferably 95 to 100 parts by mass of a polyamide based on 100 parts by mass of the thermoplastic resin. By containing a polyamide in the above numerical range, gas barrier properties can be ensured.

[0109] As the polyamide, nylon 6, nylon 66, nylon 11, nylon 12, nylon 610, nylon 6 / 66 copolymer, nylon 6 / 12 copolymer, nylon 46, nylon 6T, nylon 9T, nylon MXD6, and the like can be given, of which nylon 6 and nylon 6 / 12 copolymer are preferable.

[0110] The thermoplastic resin constituting the inner layer can contain a resin other than a polyamide. As the resin other than a polyamide, a polyester, a polyvinyl alcohol, a polyketone, and the like can be given.

[0111] The elastomer constituting the domain of the thermoplastic resin composition constituting the inner layer includes an elastomer having a polyisobutylene skeleton. The elastomer having a polyisobutylene skeleton is as described above.

[0112] The content of the thermoplastic resin in the thermoplastic resin composition constituting the inner layer is preferably 30 to 170 parts by mass, more preferably 35 to 169 parts by mass, and further preferably 40 to 100 parts by mass, based on 100 parts by mass of the elastomer in the thermoplastic resin composition constituting the inner layer. By having the content of the elastomer in the above numerical range, the dispersed state of the island-in-sea structure in which the elastomer becomes a domain can be ensured, and softness and gas barrier properties can be ensured.

[0113] The thermoplastic resin composition constituting the inner layer preferably contains a phenylenediamine-based or quinoline-based anti-aging agent. By having the thermoplastic resin composition contain a phenylenediamine-based or quinoline-based anti-aging agent, heat aging resistance is improved.

[0114] The phenylenediamine-based anti-aging agent refers to an anti-aging agent having an aromatic ring in the molecular structure, the aromatic ring having 2 secondary amines as substituents, and is preferably at least one selected from the group consisting of N-phenyl-N'-(l,3-dimethylbutyl)-p-phenylenediamine, N-phenyl-N'-(l-methylheptyl)-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N,N'-di-2-naphthyl-p-phenylenediamine, and N,N'-diphenyl-p-phenylenediamine, and more preferably N-phenyl-N'-(l,3-dimethylbutyl)-p-phenylenediamine.

[0115] The quinoline-based anti-aging agent refers to an anti-aging agent having a quinoline skeleton in the molecular structure, and is preferably 2,2,4-trimethyl-l,2-dihydroquinoline polymer.

[0116] The content of the phenylenediamine-based anti-aging agent or the quinoline-based anti-aging agent in the thermoplastic resin composition constituting the inner layer (when both the phenylenediamine-based anti-aging agent and the quinoline-based anti-aging agent are contained, the total of the content of the phenylenediamine-based anti-aging agent and the content of the quinoline-based anti-aging agent) is preferably 0.1 to 10 parts by mass, and more preferably 0.1 to 5.0 parts by mass, based on 100 parts by mass of the total amount of the thermoplastic resin and the elastomer.

[0117] The thermoplastic resin composition constituting the inner layer preferably contains a processing aid. The processing aid is useful for improving the extrusion processability of the thermoplastic resin composition.

[0118] The processing aid is not particularly limited, and is preferably at least one selected from the group consisting of fatty acids, fatty acid metal salts, fatty acid esters, and fatty acid amides.

[0119] As the fatty acid, stearic acid, palmitic acid, lauric acid, oleic acid, linoleic acid, and the like can be given, and stearic acid is preferred.

[0120] As the fatty acid metal salt, calcium stearate, potassium stearate, zinc stearate, magnesium stearate, sodium stearate, and the like can be given, and calcium stearate is preferred.

[0121] As the fatty acid ester, glycerin monostearate, sorbitan stearate, stearyl stearate, ethylene glycol distearate, and the like can be given.

[0122] As the fatty acid amide, stearic acid monoamide, oleic acid monoamide, ethylene bis-stearamide, and the like can be given.

[0123] The content of the processing aid in the thermoplastic resin composition constituting the inner layer is preferably 0.2 to 10 parts by mass, and more preferably 1 to 8 parts by mass, and further preferably 1 to 5 parts by mass, based on 100 parts by mass of the total amount of the thermoplastic resin and the elastomer.

[0124] The thermoplastic resin composition constituting the inner layer preferably contains a viscosity stabilizer. By containing the viscosity stabilizer, the increase in viscosity at the time of extrusion molding of the thermoplastic resin composition can be suppressed, and the generation of stagnate matter can be effectively reduced, so that the processability becomes good.

[0125] As the viscosity stabilizer, a divalent metal oxide, an ammonium salt, a carboxylate salt, or the like can be given.

[0126] As the divalent metal oxide, zinc oxide, magnesium oxide, copper oxide, calcium oxide, iron oxide, or the like can be given, and zinc oxide or magnesium oxide is preferable, and zinc oxide is more preferable.

[0127] As the ammonium salt, ammonium carbonate, ammonium bicarbonate, ammonium chloride, ammonium bromide, ammonium sulfate, ammonium nitrate, ammonium acetate, an alkylammonium, or the like can be given.

[0128] As the carboxylate salt, sodium acetate, potassium acetate, zinc acetate, copper acetate, sodium oxalate, ammonium oxalate, calcium oxalate, iron oxalate, or the like can be given.

[0129] The viscosity stabilizer is most preferably zinc oxide.

[0130] The content of the viscosity stabilizer in the thermoplastic resin composition constituting the inner layer is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and further preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total amount of the thermoplastic resin and the elastomer.

[0131] It is preferable to contain 50% by mass or more of the viscosity stabilizer in the base. By containing 50% by mass or more of the viscosity stabilizer in the base, the increase in viscosity at the time of extrusion molding of the thermoplastic resin composition can be suppressed, and the generation of stagnate matter can be effectively reduced, so that the processability becomes good.

[0132] The thermoplastic resin composition constituting the inner layer can contain various additives in addition to the above-described components.

[0133] The manufacturing method of the refrigerant delivery hose is not particularly limited, and can be manufactured as described below. First, the inner layer is extrusion molded into a tubular shape, and then the fiber as the reinforcing layer is braided on the tube, and the outer layer is coated on the fiber by extrusion molding.

[0134] The manufacturing method of the refrigerant delivery hose of the present application preferably includes a step of kneading an elastomer having a polyisobutylene skeleton, a crosslinkable resin, and a crosslinking agent for the elastomer having a polyisobutylene skeleton to prepare a composition for the outer layer, and a step of adding a silanol condensation catalyst to the composition for the outer layer at the time of extrusion molding of the hose, and extrusion molding the composition to which the silanol condensation catalyst is added to form the outer layer.

[0135] The cross-linkable resin refers to a resin before cross-linking of the above cross-linking resin. The cross-linkable resin is preferably the above silane-modified resin.

[0136] The step of melt-kneading the elastomer having a polyisobutylene skeleton, the cross-linkable resin, and the cross-linking agent for the elastomer having a polyisobutylene skeleton to prepare the outer layer composition, hereinafter also simply referred to as "melt-kneading step".

[0137] The melt-kneading is not limited, and can be performed using a kneader, a single- or twin-screw kneader-extruder, or the like.

[0138] The temperature of the melt-kneading is not limited as long as the melt-kneading can be performed, and is preferably 170 to 240°C.

[0139] The time of the melt-kneading is not limited as long as the target kneaded product can be prepared, and is preferably 2 to 10 minutes.

[0140] In the melt-kneading step, the elastomer having a polyisobutylene skeleton, the cross-linkable resin, the cross-linking agent for the elastomer having a polyisobutylene skeleton, and various additives such as an anti-aging agent, a processing aid, a viscosity stabilizer, and the like, as needed, are fed to a kneader or the like and melt-kneaded.

[0141] However, it is preferable that the silanol condensation catalyst is not added in the melt-kneading step. In the case where the silanol condensation catalyst is added in the melt-kneading step, when the outer layer composition prepared in the melt-kneading step contacts water vapor in the atmosphere, the cross-linkable resin in the outer layer composition gradually cross-links, and the outer layer composition after cross-linking becomes difficult to be molded. Therefore, the silanol condensation catalyst is preferably added to the outer layer composition at the time of molding.

[0142] The step of adding the silanol condensation catalyst to the outer layer composition at the time of extrusion molding of the hose, and extrusion-molding the composition to which the silanol condensation catalyst is added to form the outer layer, hereinafter also simply referred to as "outer layer forming step".

[0143] The extrusion molding at the time of refers to simultaneously with the extrusion molding or within 6 hours before the extrusion molding.

[0144] The extrusion molding is not limited, and can be performed using a kneader-extruder, and preferably using a twin-screw kneader-extruder.

[0145] The addition of the silanol condensation catalyst can be added to the outer layer composition before feeding to the kneader-extruder, or the outer layer composition and the silanol condensation catalyst can be simultaneously fed to the kneader-extruder, or the outer layer composition and the silanol condensation catalyst can be separately fed to each of the feeding ports of the kneader-extruder.

[0146] As for the silanol condensation catalyst, it can be added directly to the composition for the outer layer itself, preferably as a silanol condensation catalyst-containing master batch in which a resin and the silanol condensation catalyst are compounded.

[0147] The composition to which the silanol condensation catalyst is added is extrusion-molded on the outer surface of the reinforcing layer to form the outer layer.

[0148] As for the conditions of the extrusion molding, there is no limitation as long as the outer layer can be formed.

[0149] The manufacturing method of the refrigerant delivery hose of the present application preferably includes a step of bringing the outer layer into contact with water or water vapor to crosslink the base in the resin composition constituting the outer layer after the outer layer forming step (hereinafter also referred to simply as "water contact step"). By carrying out the water contact step, the crosslinkable resin in the resin composition constituting the outer layer is crosslinked, and the heat resistance of the outer layer is improved.

[0150] When the outer layer formed by the outer layer forming step is brought into contact with water vapor in the atmosphere, the crosslinkable resin in the outer layer is gradually crosslinked to generate a crosslinked resin, and the outer layer is crosslinked, and when it is intended to rapidly crosslink the outer layer, the water contact step is preferably carried out.

[0151] There is no limitation as to the method of bringing into contact with water or water vapor, and methods such as a method of immersing in a water bath, a method of spraying water, and a method of placing in an atmosphere containing water vapor can be given, and the method of placing in an atmosphere containing water vapor is preferred. In the method of placing in an atmosphere containing water vapor, it is left standing in air having a temperature of room temperature to 200°C, preferably room temperature to 100°C, and a relative humidity of 30 to 100%, preferably 40 to 90%, for 1 minute to 1 month, preferably 1 hour to 1 week, more preferably 1 to 4 days. More specifically, it is left standing in air having a temperature of 25°C and a relative humidity of 50% for 72 hours or more.

[0152] In the case where the crosslinkable resin is a silane-modified resin, by the water contact step, the hydrolyzable silyl group (preferably alkoxy silyl group) of the silane-modified resin in the outer layer is hydrolyzed to generate a silanol group, and a condensation reaction occurs between the silanol groups to form a siloxane bond (Si-O-Si) to be crosslinked, and a crosslinked outer layer is obtained.

[0153] Example

[0154] [Raw Materials]

[0155] The raw materials used in the following examples and comparative examples are as follows.

[0156] (Raw Materials for Outer Layer)

[0157] IIR: Butyl rubber "Exxon Butyl" 268 manufactured by Exxon Mobil Chemical Company

[0158] Br-IIR: bromobutyl rubber "Exxon Bromobutyl" 2255 manufactured by ExxonMobil Chemical Company

[0159] Crosslinkable resin: silane-modified polypropylene "Linklon" (registered trademark) XPM800HM manufactured by Mitsubishi Chemical Corporation

[0160] Polypropylene: propylene homopolymer "Prime Polymer" (registered trademark) J108M manufactured by Prime Polymer Co., Ltd.

[0161] PP / EPDM: PP / EPDM thermoplastic elastomer "Santoprene" (registered trademark) 111-35 manufactured by ExxonMobil Japan Limited

[0162] Resin-based crosslinking agent-1: alkylphenol formaldehyde resin "Hitanol" (registered trademark) 2501Y manufactured by Hitachi Chemical Co., Ltd.

[0163] Resin-based crosslinking agent-2: brominated alkylphenol formaldehyde resin "Tackirol" (registered trademark) 250-I manufactured by Taga Chemical Industries, Ltd.

[0164] Zinc white: 3 kinds of zinc oxide manufactured by Shiseido Chemicals Co., Ltd.

[0165] Silanol condensation catalyst: silane crosslinking agent masterbatch "Catalyst MB" PZ010 manufactured by Mitsubishi Chemical Corporation

[0166] Anti-aging agent-1: hindered phenol-based anti-aging agent "IRGANOX" (registered trademark) 1010 manufactured by BASF Japan Ltd.

[0167] (Inner layer raw material)

[0168] Butyl rubber: brominated isobutylene-p-methylstyrene copolymer rubber "EXXPRO" (registered trademark) 3745 manufactured by ExxonMobil Chemical Company

[0169] Nylon 6: nylon 6 "UBE Nylon" (registered trademark) 1011FB manufactured by Ube Industries, Ltd.

[0170] Nylon 6 / 12: nylon 6 / 12 copolymer "UBE Nylon" (registered trademark) 7024B manufactured by Ube Industries, Ltd.

[0171] Anti-aging agent-2: phenylenediamine-based anti-aging agent "SANTOFLEX" (registered trademark) 6PPD (substance name: N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine) manufactured by Solutia Inc.

[0172] Viscosity stabilizer: Zinc oxide 3 kinds manufactured by Shachi Chemical Industry Co., Ltd.

[0173] Processing aid-1: Industrial stearic acid manufactured by Chiba Fatty Acid Co., Ltd.

[0174] Processing aid-2: Calcium stearate SC-PG manufactured by Sakai Chemical Industry Co., Ltd.

[0175] [Preparation of the resin composition for the outer layer]

[0176] The resin compositions for the outer layer Al to Al l, Al and A'2 were prepared by the following method. Each of the raw materials except for the silanol condensation catalyst was put into a twin-screw kneader-extruder (manufactured by Nippon Steel & Sumikin Engineering Co., Ltd.) at the compounding ratio shown in Table 1, and kneaded at 235°C for 3 minutes. The kneaded product was continuously extruded into a strand shape from the extruder, and after water-cooling, cut with a knife to obtain the resin composition for the outer layer Al to Al l, Al and A'2 in a pellet form. In the measurement and evaluation of the water vapor permeability, softness, extrusion processability and breaking strength, the silanol condensation catalyst was added at the time of sheet formation using an extruder, and at the time of tubular extrusion of the resin composition for the outer layer when making a refrigerant delivery hose.

[0177] As the resin composition for the outer layer A'3, commercially available PP / EPDM thermoplastic elastomer "Santoprene" (registered trademark) 111-35 (thermoplastic elastomer in which the matrix is polypropylene and the domain is an ethylene-propylene-diene copolymer) was used.

[0178] For the resin compositions for the outer layer Al to Al l and A' l to A'3, the water vapor permeability, softness, extrusion processability and breaking strength at 150°C TB were measured and evaluated. 150 The measurement and evaluation results are shown in Table 1.

[0179] [Preparation of the thermoplastic resin composition for the inner layer]

[0180] Each of the raw materials was put into a twin-screw kneader-extruder (manufactured by Nippon Steel & Sumikin Engineering Co., Ltd.) at the compounding ratio shown in Table 2, and kneaded at 235°C for 3 minutes. The kneaded product was continuously extruded into a strand shape from the extruder, and after water-cooling, cut with a knife to obtain the thermoplastic resin composition for the inner layer Bl to B4 in a pellet form.

[0181] [Manufacture of a refrigerant delivery hose]

[0182] On a mandrel on which a releasing agent was previously applied, the inner layer resin composition was extruded into a tubular shape having a thickness shown in Tables 3 to 5 using an extruder. On this, reinforcing filaments of polyester were woven using a braider, and the outer layer resin composition to which a silanol condensation catalyst was added was extruded into a tubular shape having a thickness shown in Tables 3 to 5 using an extruder, the mandrel was pulled out, whereby a hose composed of an inner layer / strengthening layer / outer layer was produced.

[0183] For the produced hose, after the outer layer resin composition was crosslinked by leaving it in air at a temperature of 25°C and a relative humidity of 50% for 72 hours or more, heat resistance, moisture permeation resistance, refrigerant permeation resistance, and softness were evaluated. The evaluation results are shown in Tables 3 to 5.

[0184] The measurement and evaluation methods are described below.

[0185] [Measurement of water vapor permeability]

[0186] Using a 40 mmφ single-screw extruder (Pla Tech Co., Ltd.) equipped with a 550 mm wide T-die, the temperature of the cylinder and the die was set to the melting point of the polymer component having the highest melting point in the test composition + 10°C, and the outer layer resin composition to which a silanol condensation catalyst was added was molded into a sheet having an average thickness of 0.2 mm under conditions of a cooling roll temperature of 50°C and a take-up speed of 3 m / min. The produced sheet was left in air at a temperature of 25°C and a relative humidity of 50% for 72 hours or more, and a sheet of the crosslinked resin composition was produced.

[0187] The obtained sheet was cut out, and a water vapor permeation tester (GTR Tec Co., Ltd.) was used to measure the water vapor permeability at a temperature of 60°C and a relative humidity of 95%.

[0188] [Evaluation of softness of the outer layer resin composition]

[0189] The crosslinked sheet having an average thickness of 0.2 mm produced in the measurement of water vapor permeability was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed at a temperature of 25°C and a speed of 500 mm / min based on the measurement method prescribed in JIS K6251 "Vulcanized rubber and thermoplastic rubber - Method for determining tensile properties", and the stress at 10% elongation (10% modulus) was calculated from the obtained stress-strain curve.

[0190] The 10% modulus is an index of softness, and the smaller the 10% modulus, the more excellent the softness. The softness was evaluated as O when the 10% modulus was 10 MPa or less, and as X when the 10% modulus exceeded 10 MPa.

[0191] [Evaluation of extrusion processability]

[0192] A 40 mmφ single-screw extruder (Pla Tech Co., Ltd.) equipped with a 550 mm wide T-die was used, and the temperature of the cylinder and the die was set to the melting point of the polymer component having the highest melting point in the test composition + 10°C. The test sample of the resin composition to which a silanol condensation catalyst was added was molded into a sheet having an average thickness of 0.2 mm under the conditions of a cooling roll temperature of 50°C and a take-up speed of 3 m / min. The case where the molding could be performed without any problem was evaluated as O, the case where slight particles, openings, or breakage at the end of the sheet, etc. occurred was evaluated as Δ, and the case where severe particles, openings, or breakage at the end of the sheet, etc. occurred was evaluated as X.

[0193] [Measurement of Breaking Strength]

[0194] The sheet having an average thickness of 0.2 mm produced in the measurement of water vapor permeability was left to stand in air at a temperature of 25°C and a relative humidity of 50% for 72 hours or more, and a sheet of the crosslinked resin composition was produced. The sheet of the crosslinked resin composition was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed under the conditions of a temperature of 150°C and a speed of 500 mm / min based on the measurement method prescribed in JIS K6251 "Vulcanized Rubber and Thermoplastic Rubber - Method for Determining Tensile Properties", and the stress at the time of breakage was calculated from the obtained stress-strain curve, which was taken as the breaking strength TB150°C of the crosslinked resin composition at 150°C. 150 .

[0195] [Evaluation of Heat Resistance]

[0196] The test sample left in an oven at 150°C for 240 hours was pressurized to an internal pressure of 3.5 MPa, and the sealing property of the riveted portion after heat aging was confirmed by airtightness test for 5 minutes. The case where there was no leakage was evaluated as O, and the case where there was leakage was evaluated as X.

[0197] [Evaluation of Water Vapor Permeation Resistance]

[0198] Using each test sample left in an oven at 50°C for 5 hours, a desiccant having a volume corresponding to 80% of the internal volume of the test sample was filled into the test sample and sealed. The test sample was left in an atmosphere at a temperature of 50°C and a relative humidity of 95%, and the mass increase amount of the desiccant after 120 hours to 360 hours was measured, and the water vapor permeation coefficient [mg / (240h·cm2)] was calculated by dividing the mass increase amount at 240 hours by the internal surface area of the test sample. 2 The smaller the value of the water vapor permeation coefficient, the more excellent the water vapor permeation resistance. If the value is 3 or less, it can be evaluated as having practically sufficient water vapor permeation resistance. In Tables 3 to 5, the case where the value was 3 or less was evaluated as O, and the case where the value exceeded 3 was evaluated as X.

[0199] [Evaluation of refrigerant permeability]

[0200] The measurements were performed based on SAE J2064 AUG2015. In each test sample with a length of 1.07 m, every 1 cm... 3 The test sample was sealed with 70% ± 3% refrigerant (HFO-1234yf). The sample was placed at 80°C for 25 days, and the daily mass loss (refrigerant permeation) [kg / day] was measured during the final predetermined period (days 5-7) of the 25-day period. This mass loss was divided by the internal surface area of ​​the test sample, and the resulting value was converted to an annual value. The refrigerant permeation coefficient [kg / (m²)] was then calculated. 2 The smaller the refrigerant permeability coefficient, the better the refrigerant permeability resistance. If the value is below 3, it can be evaluated as having practically sufficient refrigerant permeability resistance. In Tables 3 to 5, cases with a value below 3 are evaluated as ○, and cases with a value above 3 are evaluated as ×.

[0201] [Evaluation of the flexibility of the hose]

[0202] like Figure 2 As shown, for each test sample S, one end in the length direction is fixed using a clamp or other fixing tool. A spring scale is installed at the other end, which is a predetermined length L (120 + hose outer diameter / 2) × π [mm] away from the fixed position, and the sample is stretched to bend from the state shown by the dashed line to the state shown by the solid line. The tensile force F measured by the spring scale in the horizontal direction under the bent state with an inner radius R of 120 mm is used as an evaluation index. The smaller the value of this tensile force F, the easier the test sample S is to bend, and the better its flexibility. If the tensile force F is less than 20 N, it can be evaluated as having sufficient practical flexibility. In Tables 3 to 5, cases where the tensile force F is less than 20 N are evaluated as ○, and cases where the tensile force F exceeds 20 N are evaluated as ×.

[0203] [Table 1]

[0204]

[0205] [Table 2]

[0206] Table 2. Formulation of thermoplastic resin compositions for the inner layer.

[0207]

[0208] [Table 3]

[0209]

[0210] [Table 4]

[0211]

[0212] [Table 5]

[0213]

[0214] Industrial applicability

[0215] The refrigerant delivery hose of the present application can be used well for delivering refrigerants of air conditioners of automobiles and the like.

[0216] Explanation of reference numerals

[0217] 1 Refrigerant delivery hose

[0218] 2 Inner layer

[0219] 3 Reinforcing layer

[0220] 4 Outer layer

[0221] F Tensile force

[0222] L Predetermined length

[0223] R Radius of hose inner side

[0224] S Test sample

Claims

1. A refrigerant delivery hose which is a refrigerant delivery hose comprising an outer layer, a reinforcing layer, and an inner layer, the outer layer being composed of a resin composition containing 100 parts by mass of an elastomer having a polyisobutylene skeleton, 10 to 150 parts by mass of a crosslinking resin, and 2.5 to 25 parts by mass of a crosslinking agent for the elastomer having a polyisobutylene skeleton, the water vapor permeability of the resin composition constituting the outer layer being 3.0 g mm / (m2 24h) or less. 2 ·24h) or less.

2. The refrigerant delivery hose according to claim 1, wherein the crosslinking agent for the elastomer having a polyisobutylene skeleton contains zinc white and an alkylphenol formaldehyde resin.

3. The refrigerant delivery hose according to claim 1, wherein the content of the zinc white is 1 to 10 parts by mass based on 100 parts by mass of the elastomer having a polyisobutylene skeleton, and the content of the alkylphenol formaldehyde resin is 1.5 to 15 parts by mass based on 100 parts by mass of the elastomer having a polyisobutylene skeleton, in the resin composition constituting the outer layer.

4. The refrigerant delivery hose according to claim 1, wherein the elastomer having a polyisobutylene skeleton in the resin composition constituting the outer layer is butyl rubber or modified butyl rubber, and the elastomer having a polyisobutylene skeleton is dynamically crosslinked.

5. The refrigerant delivery hose according to claim 1, wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked by a silane-modified resin obtained by modifying a thermoplastic resin with a silane compound.

6. The refrigerant delivery hose according to claim 1, wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked by a silane-modified polyolefin obtained by modifying a polyolefin with a silane compound.

7. The refrigerant delivery hose according to claim 1, wherein the crosslinked resin in the resin composition constituting the outer layer is crosslinked by a silane-modified polypropylene obtained by modifying a polypropylene with a silane compound.

8. The refrigerant delivery hose according to claim 1, wherein the anti-aging agent is contained in an amount of 1 to 10 parts by mass based on 100 parts by mass of the elastomer having a polyisobutylene skeleton in the resin composition constituting the outer layer.

9. The refrigerant delivery hose according to claim 1, wherein the resin composition constituting the outer layer has a breaking strength TB at 150°C of 1.0 MPa or more. 150 1.0 MPa or more.

10. The refrigerant delivery hose according to claim 1, wherein the resin composition constituting the outer layer contains a base containing a crosslinked resin and a domain containing the elastomer having a polyisobutylene skeleton dispersed in the base, and the base is crosslinked.

11. The refrigerant delivery hose according to claim 1 or 10, wherein the resin composition constituting the outer layer contains a base containing a crosslinked resin and a domain containing the elastomer having a polyisobutylene skeleton dispersed in the base, and the domain is crosslinked.

12. The refrigerant delivery hose according to claim 1, wherein the inner layer is constituted by a thermoplastic resin composition containing 100 parts by mass of an elastomer and 30 to 170 parts by mass of a thermoplastic resin, the thermoplastic resin composition has an island-in-sea structure in which the elastomer exists as a domain in a base containing the thermoplastic resin, the thermoplastic resin contains 50 to 100 parts by mass of a polyamide based on 100 parts by mass of the thermoplastic resin, the elastomer contains an elastomer having a polyisobutylene skeleton, and the thermoplastic resin composition further contains a processing aid and an anti-aging agent of a phenylenediamine type or a quinoline type.

13. A method of manufacturing the refrigerant delivery hose according to claim 1, the method comprising: the elastomer having a polyisobutylene skeleton, a crosslinkable resin, and a crosslinking agent for the elastomer having a polyisobutylene skeleton are melt-kneaded to prepare a composition for the outer layer, and a silanol condensation catalyst is added to the composition for the outer layer at the time of extrusion molding of the hose, and the composition to which the silanol condensation catalyst is added is extrusion-molded to form the outer layer.

14. The method according to claim 13, comprising a step of contacting the outer layer with water or water vapor after the step of forming the outer layer, to crosslink the matrix in the resin composition constituting the outer layer.

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