Thermoplastic resin composition for refrigerant delivery hose and refrigerant delivery hose

Abstract

The present invention provides a water vapor barrier material that balances the required flexibility, heat resistance, heat aging resistance, and water vapor barrier properties of a refrigerant delivery hose. The present invention is a thermoplastic resin composition for a refrigerant delivery hose comprising a thermoplastic resin and an elastomer, characterized in that the 10% modulus M10 [MPa] measured at 25°C, the water vapor permeation coefficient measured at a temperature of 60°C and a relative humidity of 100%, and the breaking strength TB measured in a tensile test at 150°C satisfy formula (1), formula (2), and formula (3). 150 [MPa] measured at 25°C, the water vapor permeation coefficient measured at a temperature of 60°C and a relative humidity of 100%, and the breaking elongation EB measured in a tensile test at 150°C satisfy formula (1), formula (2), and formula (3). 150 [MPa] measured at 25°C, the water vapor permeation coefficient measured at a temperature of 60°C and a relative humidity of 100%, and the breaking elongation EB measured in a tensile test at 150°C satisfy formula (1), formula (2), and formula (3). 150 [MPa] measured at 25°C, the water vapor permeation coefficient measured at a temperature of 60°C and a relative humidity of 100%, and the breaking elongation EB measured in a tensile test at 150°C satisfy formula (1), formula (2), and formula (3). 150 [MPa] measured at 25°C, the water vapor permeation coefficient measured at a temperature of 60°C and a relative humidity of 100%, and the breaking elongation EB measured in a tensile test at 150°C satisfy formula (1), formula (2), and formula (3).

Description

Technical Field

[0001] This invention relates to thermoplastic resin compositions for refrigerant delivery hoses and to refrigerant delivery hoses. More specifically, this invention relates to thermoplastic resin compositions for the outer layer of refrigerant delivery hoses comprising thermoplastic resins and elastomers, and to refrigerant delivery hoses comprising an outer layer made of the aforementioned thermoplastic resin compositions. Background Technology

[0002] With increasing demands for lightweight vehicles, there are initiatives aimed at reducing weight by replacing rubber with high-barrier resins in the production of rubber hoses previously used in automobiles and thinning their walls. In particular, the refrigerant delivery hoses in current automotive air conditioning systems are primarily made of rubber; replacing this main material with high-barrier resins would enable weight reduction.

[0003] For example, Japanese Patent Application Publication No. 2009-137195 (Patent Document 1) discloses a refrigerant delivery hose using a polyamide / polyether copolymer as a moisture-resistant / water-resistant barrier material.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-137195 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In refrigerant delivery hoses used in air conditioning systems such as automobiles, water vapor permeates from the outside of the hose, causing the freezing of moisture inside the air conditioner. Therefore, it is believed that a material with excellent water vapor barrier properties is needed. However, the polyamide / polyether copolymer described in Patent Document 1 does not have sufficient flexibility and heat resistance.

[0009] This invention provides a water vapor barrier material that balances the flexibility, heat resistance, heat aging resistance, and water vapor barrier properties required for refrigerant delivery hoses.

[0010] Methods for solving problems

[0011] The present invention (I) is a thermoplastic resin composition for refrigerant delivery hoses comprising a thermoplastic resin and an elastomer, characterized in that the 10% modulus M10 [MPa] measured at 25°C and the water vapor transmission coefficient PC measured at 60°C and 100% relative humidity are... H2O [g·mm / (m 2 The fracture strength TB measured in a tensile test at 150℃ and 24h) 150 Elongation at break (EB) measured in a tensile test at 150℃ and [MPa]150 [%] Satisfies equations (1), (2), and (3),

[0012] 0.9≤M10×PC H2O ≤90 · · · (1)

[0013] 1.0≤TB 150 ≤20 · · · (2)

[0014] 50≤EB 150 · · · (3).

[0015] The present invention (II) is a refrigerant delivery hose comprising an inner layer, a reinforcing layer and an outer layer, characterized in that the outer layer comprises the thermoplastic resin composition of the present invention (I).

[0016] The present invention includes the following embodiments.

[0017] [1] A thermoplastic resin composition for refrigerant delivery hoses, comprising a thermoplastic resin and an elastomer, wherein the composition has a 10% modulus M10 [MPa] measured at 25°C and a water vapor transmission coefficient PC measured at 60°C and 100% relative humidity. H2O [g·mm / (m 2 The fracture strength TB measured in a tensile test at 150℃ and 24h) 150 Elongation at break (EB) measured in a tensile test at 150℃ and [MPa] 150 [%] Satisfies equations (1), (2), and (3),

[0018] 0.9≤M10×PC H2O ≤90 · · · (1)

[0019] 1.0≤TB 150 ≤20 · · · (2)

[0020] 50≤EB 150 · · · (3).

[0021] [2] The thermoplastic resin composition for refrigerant delivery hoses according to [1] has an elongation at break of 50% or more in a tensile test at 25°C after standing at 150°C for 168 hours.

[0022] [3] The thermoplastic resin composition for refrigerant delivery hoses according to [1] or [2], wherein the thermoplastic resin composition has an island structure consisting of a matrix comprising a thermoplastic resin and phase domains comprising an elastomer, and the ratio of the elastomer in the thermoplastic resin composition is 50% by mass or more and less than 85% by mass.

[0023] [4] The thermoplastic resin composition for a refrigerant delivery hose according to any one of [1] to [3], wherein the thermoplastic resin composition has a water vapor permeation coefficient PC measured at a temperature of 60°C and a relative humidity of 100% of 4.0 g mm / (m H2O or less. 2

[0024] [5] The thermoplastic resin composition for a refrigerant delivery hose according to any one of [1] to [4], wherein the thermoplastic resin is at least one resin selected from the group consisting of a polyamide-based resin, a polyester-based resin, and a vinyl alcohol-based resin.

[0025] [6] The thermoplastic resin composition for a refrigerant delivery hose according to any one of [1] to [5], wherein the elastomer is at least one elastomer selected from the group consisting of a butyl-based rubber, a modified butyl-based rubber, an olefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer, a polyamide elastomer, and a polyester elastomer.

[0026] [7] The thermoplastic resin composition for a refrigerant delivery hose according to any one of [1] to [6], wherein the thermoplastic resin composition contains at least one processing aid selected from the group consisting of a fatty acid, a fatty acid metal salt, a fatty acid ester, and a fatty acid amide.

[0027] [8] A refrigerant delivery hose comprising an inner layer, a reinforcing layer, and an outer layer, the outer layer comprising the thermoplastic resin composition according to any one of [1] to [7].

[0028] Effects of the Invention

[0029] The thermoplastic resin composition for a refrigerant delivery hose of the present invention is excellent in balance among softness, heat resistance, heat aging resistance, and water vapor barrier property.

[0030] The refrigerant delivery hose of the present invention is excellent in balance among softness, heat resistance, heat aging resistance, and water vapor barrier property. DETAILED DESCRIPTION

[0031] The present invention (I) relates to a thermoplastic resin composition for a refrigerant delivery hose.

[0032] ​The so-called refrigerant delivery hose is a hose for delivering a refrigerant for air conditioning or the like. The thermoplastic resin composition of the present application is particularly suitable for use in a hose for delivering a refrigerant for air conditioning of an automobile. As the refrigerant for air conditioning, there can be mentioned hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), hydrocarbons, carbon dioxide, ammonia, water, and the like, as the HFCs, there can be mentioned R410A, R32, R404A, R407C, R507A, R134a, and the like, as the HFOs, there can be mentioned R1234yf, R1234ze, 1233zd, R1123, R1224yd, R1336mzz, and the like, and as the hydrocarbons, there can be mentioned methane, ethane, propane, propylene, butane, isobutane, hexafluoropropane, pentane, and the like.

[0033] The structure of the refrigerant delivery hose is not particularly limited, and typically, it is composed of an inner layer, a reinforcing layer, and an outer layer. The thermoplastic resin composition of the present application is preferably used as a material for forming the outer layer of the refrigerant delivery hose.

[0034] When the 10% modulus [MPa] of the thermoplastic resin composition measured at 25°C is represented by M10, and the water vapor permeation coefficient [g·mm / (m 2 ·24h)] of the thermoplastic resin composition measured at a temperature of 60°C and a relative humidity of 100% is represented by PC H2O , the thermoplastic resin composition satisfies formula (1)

[0035] 0.9 ≤ M10 x PC H2O ≤ 90 · · · (1),

[0036] It is preferable that formula (1') be satisfied

[0037] 0.9 ≤ M10 x PC H2O ≤ 45 · · · (1'),

[0038] It is more preferable that formula (1") be satisfied

[0039] 5 ≤ M10 x PC H2O ≤ 45 · · · (1").

[0040] By causing the thermoplastic resin composition to satisfy the above formula, the wall thickness of the refrigerant delivery hose is thinned, and the flexibility of the hose is also improved.

[0041] The method of causing the thermoplastic resin composition to satisfy the above formula is to select a resin and a rubber that are good in water vapor barrier properties, and to blend 40% by mass or more of the rubber.

[0042] When the breaking strength [MPa] of the thermoplastic resin composition measured in a tensile test at 150°C is represented by TB 150 , the thermoplastic resin composition satisfies formula (2)

[0043] 1.0 ≤ TB 150 ≤ 20 ··· (2),

[0044] Preferably, formula (2') is satisfied

[0045] 2.0 ≤ TB 150 ≤ 20 ··· (2'),

[0046] More preferably, formula (2") is satisfied

[0047] 3.0 ≤ TB 150 ≤ 20 ··· (2").

[0048] By making the thermoplastic resin composition satisfy the above formula, the heat resistance of the refrigerant delivery hose is improved.

[0049] The method of making the thermoplastic resin composition satisfy the above formula is to use a resin having a high melting point.

[0050] When the elongation at break [%] of the thermoplastic resin composition measured in a tensile test at 150°C is represented by EB 150 , the thermoplastic resin composition satisfies formula (3)

[0051] 50 ≤ EB 150 ··· (3),

[0052] Preferably, formula (3') is satisfied

[0053] 100 ≤ EB 150 ··· (3'),

[0054] More preferably, formula (3") is satisfied

[0055] 200 ≤ EB 150 ··· (3").

[0056] By making the thermoplastic resin composition satisfy the above formula, the heat resistance of the refrigerant delivery hose is improved.

[0057] The method of making the thermoplastic resin composition satisfy the above formula is to use a resin having a high melting point.

[0058] The thermoplastic resin composition contains a thermoplastic resin and an elastomer.

[0059] The thermoplastic resin composition preferably has an island-in-sea structure composed of a matrix containing the thermoplastic resin and a phase domain containing the elastomer. By making the thermoplastic resin composition have an island-in-sea structure, a material having good softness and water vapor barrier properties and good extrusion processability can be produced.

[0060] The thermoplastic resin constituting the thermoplastic resin composition is not limited as long as it exerts the effect of the present application, but is preferably at least one resin selected from the group consisting of a polyamide-based resin, a polyester-based resin, and a vinyl alcohol-based resin.

[0061] As the polyamide-based resin, polyamide 6, polyamide 66, polyamide 11, polyamide 12, polyamide 610, a polyamide 6 / 66 copolymer, a polyamide 6 / 12 copolymer, polyamide 46, polyamide 6T, polyamide 9T, polyamide MXD6, and the like can be given, of which polyamide 12 is preferable.

[0062] As the polyester-based resin, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and the like can be given, of which polybutylene terephthalate is preferable.

[0063] As the vinyl alcohol-based resin, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, modified ethylene-vinyl alcohol copolymer, and the like can be given, of which ethylene-vinyl alcohol copolymer is preferable.

[0064] The elastomer constituting the thermoplastic resin composition is not limited as long as it exerts the effect of the present application, but is preferably at least one elastomer selected from the group consisting of a butyl-based rubber, a modified butyl-based rubber, an olefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer, a polyamide elastomer, and a polyester elastomer.

[0065] As the butyl-based rubber, butyl rubber (IIR), isobutylene-p-methylstyrene copolymer, and the like can be given.

[0066] As the modified butyl-based rubber, halogenated butyl rubber (chlorinated butyl rubber, brominated butyl rubber), halogenated isobutylene-p-methylstyrene copolymer (chlorinated isobutylene-p-methylstyrene copolymer, brominated isobutylene-p-methylstyrene copolymer), and the like can be given, of which brominated isobutylene-p-methylstyrene copolymer (Br-IPMS) is preferable.

[0067] As the olefin-based thermoplastic elastomer, ethylene-a-olefin copolymer (ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, and the like), ethylene-ethyl acrylate copolymer, maleic anhydride-modified ethylene-a-olefin copolymer, maleic anhydride-modified ethylene-ethyl acrylate copolymer, ethylene-glycidyl methacrylate copolymer, and the like can be given, of which maleic anhydride-modified ethylene-a-olefin copolymer is preferable.

[0068] As the styrene-based thermoplastic elastomer, styrene-diene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene / propylene-styrene copolymer (SEPS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-diene-styrene copolymer (SBS), styrene-isobutylene-styrene block copolymer (SIBS), and maleic anhydride-modified products thereof, and the like can be given, of which styrene-isobutylene-styrene block copolymer (SIBS), maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer are preferable.

[0069] The polyamide elastomer (TPA) is a thermoplastic elastomer in which a hard segment is polyamide (e.g., polyamide 6, polyamide 66, polyamide 11, polyamide 12) and a soft segment is polyether (e.g., polyethylene glycol, polypropylene glycol). The polyamide elastomer has been marketed, and a marketed product can be used in the present application. As the marketed product of the polyamide elastomer, "UBESTA" (registered trademark) XPA series manufactured by Ube Industries, Ltd., "PEBAX" (registered trademark) manufactured by Arkema, and the like can be given.

[0070] The polyester elastomer (TPEE) is a thermoplastic elastomer in which a hard segment is polyester (e.g., polybutylene terephthalate) and a soft segment is polyether (e.g., polytetramethylene glycol) or polyester (e.g., aliphatic polyester). The polyester elastomer has been marketed, and a marketed product can be used in the present application. As the marketed product of the polyester elastomer, "PELPRENE" (registered trademark) manufactured by Toyobo Co., Ltd., "HYTREL" (registered trademark) manufactured by Toray-Dupont Co., Ltd., and the like can be given.

[0071] The ratio of the elastomer in the thermoplastic resin composition is preferably 50% by mass or more and less than 85% by mass, more preferably 55% by mass or more and less than 85% by mass, and further preferably 60% by mass or more and less than 85% by mass. If the ratio of the elastomer is too small, the softness of the hose becomes insufficient. If the ratio of the elastomer is too large, the extrusion processability of the hose becomes poor.

[0072] The ratio of the thermoplastic resin in the thermoplastic resin composition is preferably more than 15% by mass and 50% by mass or less, more preferably more than 15% by mass and 45% by mass or less, and further preferably more than 15% by mass and 40% by mass or less. If the ratio of the thermoplastic resin is too small, the extrusion processability of the hose becomes poor. If the ratio of the thermoplastic resin is too large, the softness of the hose becomes insufficient.

[0073] The thermoplastic resin composition preferably contains a processing aid. By adding the processing aid, the extrusion processability of the thermoplastic resin composition can be improved.

[0074] The processing aid is preferably at least one processing aid selected from the group consisting of a fatty acid, a fatty acid metal salt, a fatty acid ester, and a fatty acid amide.

[0075] As the fatty acid, stearic acid, palmitic acid, oleic acid, and the like can be given, with stearic acid being preferred.

[0076] As the fatty acid metal salt, calcium stearate, magnesium stearate, zinc stearate, barium stearate, and the like can be given, with calcium stearate and magnesium stearate being preferred.

[0077] As the fatty acid ester, fatty acid esters obtained by esterification of higher fatty acids obtained by hydrolysis of coconut oil, castor oil, palm oil, beef tallow, and the like with lower alcohols, higher alcohols, polyhydric alcohols, and the like can be given.

[0078] As the fatty acid amide, stearic amide, palmitic amide, oleic amide, and the like can be given.

[0079] The content of the processing aid is not limited as long as the effects of the present application are exerted, but is preferably 1.0 to 5.0 mass%, more preferably 1.0 to 3.0 mass%, and further preferably 1.0 to 2.0 mass%.

[0080] The thermoplastic resin composition can contain a crosslinking agent. By adding the crosslinking agent, the elastomer is crosslinked, and it is possible to incorporate 50 mass% or more of the elastomer.

[0081] As the crosslinking agent, a compound having multiple amino groups in one molecule is preferred, with diamines such as N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), 3,3'-diaminodiphenyl sulfone (3,3'-DAS), 4,4'-diaminodiphenyl sulfone (4,4'-DAS), and the like being preferred.

[0082] The amount of the crosslinking agent added is not limited as long as the effects of the present application are exerted, but is preferably 0 to 6 mass%, more preferably 1 to 5 mass%, and further preferably 2 to 5 mass%.

[0083] The thermoplastic resin composition can also contain an additive other than the processing aid and the crosslinking agent. As the additive other than the processing aid and the crosslinking agent, heat aging preventives, color master batches can be given.

[0084] The elongation at break of the thermoplastic resin composition after standing at 150°C for 168 hours, measured in a tensile test at 25°C, is preferably 50% or more, more preferably 100% or more, and further preferably 200% or more. Hereinafter, the elongation at break of the thermoplastic resin composition after standing at 150°C for 168 hours, measured in a tensile test at 25°C, is referred to as "elongation at break after heat aging". By bringing the elongation at break after heat aging of the thermoplastic resin composition within the above numerical range, the heat aging resistance of a hose made using the thermoplastic resin composition is improved. The method of bringing the elongation at break after heat aging of the thermoplastic resin composition within the above numerical range is to use a resin to which a heat aging preventive agent is added, or a resin having a high melting point.

[0085] The water vapor permeation coefficient PC of the thermoplastic resin composition, measured at a temperature of 60°C and a relative humidity of 100%, is preferably 4.0 g-mm / (m H2O ·24h) or less, more preferably 3.8 g-mm / (m 2 ·24h) or less, and further preferably 3.5 g-mm / (m 2 ·24h) or less. By bringing the water vapor permeation coefficient PC 2 of the thermoplastic resin composition within the above numerical range, the water vapor barrier property of a hose made using the thermoplastic resin composition is improved. The method of bringing the water vapor permeation coefficient PC H2O of the thermoplastic resin composition within the above numerical range is to use a butyl-based rubber or a modified butyl-based rubber as the elastomer. H2O

[0086] The method of producing the thermoplastic resin composition is not particularly limited, and the thermoplastic resin, the elastomer, and additives such as a processing aid, a crosslinking agent, and the like, if used, can be mixed by using a twin-screw mixing extruder or the like.

[0087] The present application (II) relates to a refrigerant delivery hose.

[0088] The refrigerant delivery hose of the present application (II) is characterized by comprising an inner layer, a reinforcing layer, and an outer layer, and the outer layer comprises the thermoplastic resin composition of the present application (I).

[0089] With the refrigerant delivery hose of the present application (II), by making the outer layer comprise the thermoplastic resin composition of the present application (I), the balance of flexibility, heat resistance, heat aging resistance, and water vapor barrier property is achieved.

[0090] The inner layer is not limited and is a layer made of a thermoplastic resin composition, a thermoplastic elastomer composition, a rubber, or the like.

[0091] The reinforcing layer is not limited and is, for example, a layer of a fiber woven fabric. ​

[0092] The manufacturing method of the refrigerant delivery hose is not particularly limited, and for example, the inner layer can be first extruded in a tube shape by extrusion molding, then the fiber to be the reinforcing layer is woven on the tube, and further the outer layer is coated on the fiber by extrusion molding, thereby manufacturing the refrigerant delivery hose.

[0093] The refrigerant delivery hose of the present application (II) can be used as a hose for delivering a refrigerant for air conditioning or the like, and is particularly suitable for use in a hose for delivering a refrigerant for air conditioning for a car.

[0094] Examples

[0095] [Raw materials]

[0096] The raw materials used in the following examples and comparative examples are as described below.

[0097] (Thermoplastic resin)

[0098] PA6: Polyamide 6 "UBE Nylon" 1011FB manufactured by Ube Industries, Ltd.

[0099] PA6 / 12: Polyamide 6 / 12 copolymer "UBE Nylon" 7024B manufactured by Ube Industries, Ltd.

[0100] PA12: Polyamide 12 "UBESTA" (registered trademark) 3012UE manufactured by Ube Industries, Ltd. VOH: Ethylene-vinyl alcohol copolymer (ethylene content 48%) "Sofon" (registered trademark) H4815 manufactured by Mitsubishi Chemical Corporation

[0101] PBT: Polybutylene terephthalate "Novadur" (registered trademark) 5010R manufactured by Mitsubishi Engineering-Plastics Corporation

[0102] (Elastomer)

[0103] Br-IPMS: Brominated isobutylene-p-methylstyrene copolymer "EXXPRO" (registered trademark) 3745 manufactured by ExxonMobil Chemical Company

[0104] SIBS: Styrene-isobutylene-styrene block copolymer "SIBSTAR" (registered trademark) 102T manufactured by Kaneka Corporation

[0105] Mah-EB: Maleic acid-modified ethylene-1-butene copolymer "Tafmer" (registered trademark) MH7020 manufactured by Mitsui Chemicals, Inc.

[0106] TPA: Thermoplastic polyamide elastomer "UBESTA" (registered trademark) XPA 9063X1 manufactured by Ube Industries, Ltd.

[0107] TPEE: Thermoplastic polyester elastomer "Pellethane" (registered trademark) S-3001 manufactured by Toyobo Co., Ltd.

[0108] (Processing aid)

[0109] St-Ca: Calcium stearate "SC-PG" manufactured by Sakai Chemical Industry Co., Ltd.

[0110] St-Mg: Magnesium stearate "SM-PG" manufactured by Sakai Chemical Industry Co., Ltd.

[0111] (Crosslinking agent)

[0112] 6PPD: N-phenyl-N'-(l,3-dimethylbutyl)-p-phenylenediamine "SANTOFLEX" (registered trademark) 6PPD manufactured by Solutia, Inc.

[0113] [Examples 1 to 10]

[0114] The thermoplastic resin, the elastomer, the processing aid and the crosslinking agent were put into a twin-screw kneader extruder (manufactured by Nippon Steel Co., Ltd.) in the blending ratio shown in Tables 1 and 2, and kneading was performed at 235°C for 3 minutes. The kneaded product was continuously extruded in a strand shape from the extruder, and after water cooling, it was cut by a cutter to obtain a pellet-shaped thermoplastic resin composition.

[0115] For the obtained thermoplastic resin composition, the 10% modulus M10, the water vapor permeation coefficient PC H2O , the breaking strength TB 150 , the breaking elongation EB 150 and the breaking elongation after heat aging were measured, and the extrusion processability was evaluated. The measurement / evaluation results are shown in Tables 1 and 2.

[0116] [Comparative Examples 1 to 4]

[0117] As Comparative Example 1, a thermoplastic polyester elastomer "Hytrel" (registered trademark) 4057N manufactured by DuPont-Toray Co., Ltd. was selected, as Comparative Example 2, a thermoplastic polyester elastomer "Hytrel" (registered trademark) 3001 manufactured by DuPont-Toray Co., Ltd. was selected, as Comparative Example 3, an acrylic elastomer "Triaktol" (registered trademark) XB-A60 manufactured by Aron Chemical Co., Ltd. was selected, and as Comparative Example 4, a nylon resin "Zytel" (registered trademark) ST811HS manufactured by DuPont-Toray Co., Ltd. was selected, and for them, the 10% modulus M10, the water vapor permeation coefficient PC H2O , the breaking strength TB 150 , the breaking elongation EB 150and the elongation at break after heat aging, and the extrusion processability was evaluated. The measurement / evaluation results are shown in Table 1 and Table 2.

[0118] Note that the measurement / evaluation methods for each measurement / evaluation item are described below.

[0119] [Measurement of water vapor permeation coefficient]

[0120] For the sample of the thermoplastic resin composition, a 40 mmφ single screw extruder with a T-die having a width of 200 mm (PLA-TECHNICA Co., Ltd.) 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 sample composition + 10°C, and the sample 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 pulling speed of 3 m / min.

[0121] The obtained sheet was cut out, and a water vapor permeation tester manufactured by GTR Tech Co., Ltd. was used to measure the water vapor permeation coefficient under the conditions of a temperature of 60°C and a relative humidity of 100%.

[0122] [Measurement of 10% modulus M10]

[0123] The sheet having an average thickness of 0.2 mm produced in the measurement of the water vapor permeation coefficient was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed in accordance with JIS K7161 under the conditions of a temperature of 25°C, a relative humidity of 50%, and a speed of 500 mm / min. The stress at 10% elongation (10% modulus) was calculated from the obtained stress-strain curve.

[0124] [Measurement of breaking strength TB 150 ]

[0125] The sheet having an average thickness of 0.2 mm produced in the measurement of the water vapor permeation coefficient was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed in accordance with JIS K7161 under the conditions of a temperature of 150°C and a speed of 500 mm / min. The stress at the time of breakage (breaking strength) was calculated from the obtained stress-strain curve.

[0126] [Measurement of elongation at break EB 150 ]

[0127] The sheet having an average thickness of 0.2 mm produced in the measurement of the water vapor permeation coefficient was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed in accordance with JIS K7161 under the conditions of a temperature of 150°C and a speed of 500 mm / min. The elongation at the time of breakage (elongation at break) was calculated from the obtained stress-strain curve.

[0128] [Measurement of elongation at break after heat aging]

[0129] A sheet having an average thickness of 0.2 mm prepared in the measurement of water vapor permeation coefficient was left to stand in an oven set to 150°C under an air atmosphere for 168 hours, and heat aging treatment was performed. The sheet after the heat aging treatment was punched into a JIS No. 3 dumbbell shape, and a tensile test was performed in accordance with JIS K7161 at a temperature of 25°C, a relative humidity of 50%, and a tensile speed of 500 mm / min. The elongation at the time of occurrence of fracture (elongation at break) was calculated from the obtained stress-strain curve.

[0130] [Evaluation of extrusion processability]

[0131] A film of the thermoplastic resin composition was produced by extruding a sample of the thermoplastic resin composition at 235°C using a T-die sheet molding device (manufactured by TOYOMI KOGYO CO., LTD.), dropping it onto a metal cooling roll, pulling it using a pin, and winding it using a winder. The thickness of any film was made to be 200 μm, and the case where molding could be performed without problems was evaluated as O, the case where slight particles, openings, cracks at the end of the sheet, and the like were produced was evaluated as Δ, and the case where severe particles, openings, cracks at the end of the sheet, and the like were produced was evaluated as X.

[0132] [Table 1]

[0133]

[0134] [Table 2]

[0135]

[0136] Industrial applicability

[0137] The thermoplastic resin composition for a refrigerant delivery hose of the present application can be suitably used as a material for forming an outer layer of a refrigerant delivery hose.

[0138] The refrigerant delivery hose of the present application can be suitably used as a hose for delivering a refrigerant of an air conditioner of an automobile or the like.

Claims

1. A thermoplastic resin composition for refrigerant delivery hoses, comprising a thermoplastic resin and an elastomer, wherein the composition has a 10% modulus M10 measured at 25°C, and a water vapor transmission coefficient PC measured at 60°C and 100% relative humidity. H2O The tensile strength TB measured at 150℃ 150 Elongation at break (EB) measured in a tensile test at 150℃ 150 Satisfying equations (1), (2), and (3), the unit of the 10% modulus M10 is MPa, and the water vapor transmission coefficient PC H2O The unit is g·mm / (m 2 •24h), the fracture strength TB 150 The unit is MPa, and the elongation at break EB 150 The unit is %. 0.9≤M10×PC H2O ≤90···(1), 1.0≤TB 150 ≤20···(2), 50≤EB 150 ···(3), The thermoplastic resin contains a mixture of polyamide 6 and polyamide 6 / 12 copolymer, polyamide 12, ethylene-vinyl alcohol copolymer, or polybutylene terephthalate, and When the thermoplastic resin contains a mixture of polyamide 6 and a polyamide 6 / 12 copolymer or polyamide 12, the elastomer contains a brominated isobutylene-p-methylstyrene copolymer. When the thermoplastic resin contains an ethylene-vinyl alcohol copolymer, the elastomer contains a maleic acid-modified ethylene-1-butene copolymer, a mixture of maleic acid-modified ethylene-1-butene copolymer and thermoplastic polyester elastomer, a mixture of maleic acid-modified ethylene-1-butene copolymer and thermoplastic polyamide elastomer, or a styrene-isobutylene-styrene block copolymer. When the thermoplastic resin contains polybutylene terephthalate, the elastomer contains maleic acid-modified ethylene-1-butene copolymer.

2. The thermoplastic resin composition for refrigerant delivery hoses according to claim 1 has an elongation at break of 50% or more in a tensile test at 25°C after standing at 150°C for 168 hours.

3. The thermoplastic resin composition for refrigerant delivery hoses according to claim 1 or 2, wherein the thermoplastic resin composition has an island structure comprising a matrix containing a thermoplastic resin and phase domains containing an elastomer, and the proportion of the elastomer in the thermoplastic resin composition is 50% by mass or more and less than 85% by mass.

4. The thermoplastic resin composition for refrigerant delivery hoses according to claim 1 or 2, wherein the water vapor transmission coefficient PC of the thermoplastic resin composition is measured at a temperature of 60°C and a relative humidity of 100%. H2O 4.0 g·mm / (m 2 ·24h and below.

5. The thermoplastic resin composition for refrigerant delivery hoses according to claim 1 or 2, wherein the thermoplastic resin composition comprises at least one processing aid selected from the group consisting of fatty acids, fatty acid metal salts, fatty acid esters and fatty acid amides.

6. A refrigerant delivery hose comprising an inner layer, a reinforcing layer, and an outer layer, wherein the outer layer comprises the thermoplastic resin composition according to any one of claims 1 to 5.

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