Hose for fluid delivery

Abstract

A fluid transport hose providing excellent fatigue resistance at low temperatures and impact pressure resistance at high temperatures is characterized by comprising an inner layer formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer, a reinforcing layer disposed outside the inner layer, and an outer layer disposed outside the reinforcing layer. The storage modulus E' of the thermoplastic resin composition at -40°C is also described. L , and the energy storage modulus E' at 80℃ H Satisfying equations (1), (2) and (3), E' L ≤1500MPa···(1)E' H ≥40MPa···(2)E' H / E' L ≥0.05···(3).

Description

Technical Field

[0001] This invention relates to hoses for fluid delivery. Background Technology

[0002] A hydrogen transport component is known, comprising a hydrogen barrier layer formed of a resin composition comprising polyamide 11 and a modified olefin elastomer, a reinforcing layer disposed outside the hydrogen barrier layer, and an outer coating comprising a polyamide resin disposed outside the reinforcing layer (International Publication No. 2018 / 155491).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2018 / 155491 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The hydrogen transport component described in International Publication No. 2018 / 155491 has insufficient resistance to shock pressure at high temperatures.

[0008] This invention provides a fluid transport hose with excellent fatigue resistance at low temperatures and impact pressure resistance at high temperatures.

[0009] Methods for solving problems

[0010] The inventors discovered that by crosslinking the elastomer in the dispersed phase of a thermoplastic resin composition comprising a continuous phase containing a thermoplastic resin and a dispersed phase containing an elastomer, the decrease in elastic modulus at high temperatures can be suppressed, thus completing the present invention.

[0011] The invention is characterized by comprising a fluid delivery hose consisting of an inner layer formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer, a reinforcing layer disposed outside the inner layer, and an outer layer disposed outside the reinforcing layer, wherein the storage modulus E' of the thermoplastic resin composition at -40°C is... L , and the energy storage modulus E' at 80℃ H It satisfies equations (1), (2) and (3).

[0012] E' L ≤1500MPa···(1)

[0013] E' H ≥40MPa···(2)

[0014] E' H / E' L ≥0.05···(3)

[0015] The present invention includes the following embodiments.

[0016] [1] A flexible hose for fluid transport, characterized in that it comprises an inner layer formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer, a reinforcing layer disposed outside the inner layer, and an outer layer disposed outside the reinforcing layer, wherein the storage modulus E' of the thermoplastic resin composition at -40°C is... L , and the energy storage modulus E' at 80℃ H It satisfies equations (1), (2) and (3).

[0017] E' L ≤1500MPa···(1)

[0018] E' H ≥40MPa···(2)

[0019] E' H / E' L ≥0.05···(3)

[0020] [2] The fluid transport hose according to [1] is characterized in that the thermoplastic resin composition comprises a continuous phase comprising a thermoplastic resin and a dispersed phase comprising an elastomer, wherein at least a portion of the elastomer is crosslinked.

[0021] [3] The fluid transport hose according to [1] or [2] is characterized in that the oxygen permeability coefficient of the thermoplastic resin composition at 21°C and 50% relative humidity is 0.1 mm·cc / (m 2 (·day·mmHg) or less.

[0022] [4] The fluid transport hose according to any one of [1] to [3] is characterized in that the thermoplastic resin is selected from at least one of polyamide resin, vinyl alcohol resin and polyester resin.

[0023] [5] The fluid transport hose according to any one of [1] to [4] is characterized in that the elastomer is selected from at least one of olefin elastomers, styrene elastomers, butyl elastomers, diene rubbers and their modifiers.

[0024] [6] A fluid transport hose according to any one of [1] to [5], characterized in that the ratio of the volume (V) of the thermoplastic resin composition exposed to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours, and the volume (V0) before exposure, to the volume at atmospheric pressure is less than 1.08.

[0025] [7] The fluid transport hose according to any one of [1] to [6] is characterized in that the amount of hydrogen dissolved when the thermoplastic resin composition is exposed to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours is less than 3000 ppm by mass.

[0026] [8] A fluid transport hose according to any one of [1] to [7], characterized in that the thermoplastic resin composition breaks more than 2 million times under repeated tensile stress at a temperature of -35°C, a strain of 18% and a frequency of 6.7 Hz.

[0027] [9] A fluid transport hose according to any one of [1] to [8], characterized in that the 10% modulus of the outer layer at 25°C is 10 MPa or less.

[0028]

[10] A fluid transport hose according to any one of [1] to [9], characterized in that the reinforcing layer comprises organic fibers or steel wires with a tensile modulus of 100 GPa or more.

[0029] The effects of the invention

[0030] The fluid transport hose of the present invention exhibits excellent fatigue resistance at low temperatures and impact pressure resistance at high temperatures. Detailed Implementation

[0031] This invention relates to hoses for fluid transport. The fluid being transported is not limited, and examples include hydrogen, air conditioning refrigerants, inactive gases, fuels, oil, and water. Specifically, the hose for fluid transport of this invention is suitable for use with hydrogen.

[0032] The fluid delivery hose of the present invention comprises an inner layer formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer, a reinforcing layer disposed outside the inner layer, and an outer layer disposed outside the reinforcing layer.

[0033] The fluid transport hose of the present invention is characterized in that the storage modulus E' of the thermoplastic resin composition at -40°C is... L , and the energy storage modulus E' at 80℃ H It satisfies equations (1), (2) and (3).

[0034] E' L ≤1500MPa···(1)

[0035] E' H ≥40MPa···(2)

[0036] E' H / E' L ≥0.05···(3)

[0037] Storage modulus E' of thermoplastic resin composition at -40°C L satisfy

[0038] E' L ≤1500MPa···(1),

[0039] Preferred satisfaction

[0040] 20MPa≤E' L ≤1450MPa···(1'),

[0041] More preferably satisfied

[0042] 50MPa≤E' L ≤1400MPa···(1”).

[0043] Through E' L The above formula is satisfied, resulting in excellent fatigue resistance of the thermoplastic resin composition at low temperatures.

[0044] Make E' L Methods that satisfy the above formula include selecting the types of thermoplastic resins and elastomers, adjusting the composition ratio, and adding plasticizers, softeners, etc.

[0045] Storage modulus E' of thermoplastic resin composition at 80°C H satisfy

[0046] 40MPa≤E' H ···(2),

[0047] Preferred satisfaction

[0048] 45MPa≤E' H ≤1000MPa···(2')

[0049] More preferably satisfied

[0050] 50MPa≤E' H ≤800MPa···(2”).

[0051] Through E' H It satisfies the above formula, thus exhibiting excellent impact resistance at high temperatures and preventing damage during fastening.

[0052] Make E' H Methods that satisfy the above formula include selecting the types of thermoplastic resins and elastomers, adjusting the composition ratio, and adding fibers and fillers.

[0053] The ratio of the energy storage modulus at 80°C to that at -40°C (E') H / E' L )satisfy

[0054] 0.05≤E' H / E' L ···(3),

[0055] Preferred satisfaction

[0056] 0.06≤E' H / E' L ≤0.30···(3'),

[0057] More preferably satisfied

[0058] 0.07≤E' H / E' L ≤0.25···(3”).

[0059] Through E' H / E' L By satisfying the above formula, the temperature dependence of the elastic modulus is small, and the rigidity of the hose is not easily affected by the operating temperature, thus achieving stable operability.

[0060] Make E' H / E' L Methods that satisfy the above formula include the selection of thermoplastic resins and elastomers, the adjustment of composition ratios, and the use of additives.

[0061] Storage modulus E' refers to the real part of the complex elastic modulus obtained from the stress-strain characteristics when dynamic strain is applied to a viscoelastic body, and corresponds to the elastic term of viscoelasticity.

[0062] The dynamic storage modulus can be determined according to the method described in JIS K7198. Specifically, after applying initial tension to the specimen, dynamic strain is introduced as a periodic sinusoidal wave through an exciter. The stress and displacement at this time are measured, and the complex elastic modulus can be determined as a constant of its real part. In this invention, it was measured at an initial tension of 5%, a frequency of 20 Hz, and a dynamic strain of 0.1%.

[0063] The inner layer of the fluid transport hose is formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer.

[0064] The thermoplastic resin composition preferably comprises a continuous phase containing a thermoplastic resin and a dispersed phase containing an elastomer. In other words, the thermoplastic resin forms the continuous phase (matrix), and the elastomer forms the dispersed phase (structural domains). That is, the thermoplastic resin composition preferably has an island structure. By having an island structure, the permeation of the transported fluid is suppressed, while fatigue resistance at low temperatures is readily obtained.

[0065] The thermoplastic resin is not limited as long as it achieves the effect of the present invention, but is preferably selected from at least one of polyamide resin, vinyl alcohol resin and polyester resin.

[0066] Examples of polyamide resins include polyamide 11, polyamide 12, polyamide 6, polyamide 6 / 66 copolymer, polyamide 610, polyamide 6 / 12 copolymer, polyamide 1010, and polyamide 1012, but polyamide 11, polyamide 12, and polyamide 1012 are preferred.

[0067] Examples of vinyl alcohol-based resins include polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), ethylene-vinyl acetate-vinyl alcohol copolymer, and ethylene-butenediol copolymer, but ethylene-vinyl alcohol copolymer is preferred. The melting point and oxygen permeability of ethylene-vinyl alcohol copolymer vary depending on the copolymerization ratio of ethylene to vinyl alcohol. A preferred copolymerization ratio of ethylene is 25–48 mol%. Among these, ethylene-vinyl alcohol copolymers with a copolymerization ratio of 48 mol% and ethylene-vinyl alcohol copolymers with a copolymerization ratio of 38 mol% are preferred.

[0068] Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, but polybutylene terephthalate is preferred.

[0069] The continuous phase may include thermoplastic resins other than polyamide resins, vinyl alcohol resins and polyester resins, and various additives, without impairing the effects of the present invention.

[0070] The elastomer is not limited as long as it achieves the effect of the present invention, but it is preferably selected from at least one of olefin elastomers, styrene elastomers, butyl elastomers, diene rubbers and their modifiers.

[0071] Examples of olefin-based elastomers include ethylene-α-olefin copolymers, ethylene-unsaturated carboxylic acid copolymers, or their derivatives. Examples of ethylene-α-olefin copolymers include ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-pentene copolymers, ethylene-hexene copolymers, ethylene-octene copolymers, and their acid-modified forms. Examples of ethylene-unsaturated carboxylic acid copolymers include ethylene-acrylic acid copolymers and ethylene-methacrylic acid copolymers.

[0072] Examples of styrene-based elastomers include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), styrene-ethylene / propylene-styrene copolymers (SEPS), styrene-ethylene / butene-styrene block copolymers (SEBS), styrene-butadiene-styrene copolymers (SBS), styrene-isobutylene-styrene block copolymers (SIBS), and their maleic anhydride-modified forms, but styrene-isobutylene-styrene block copolymers (SIBS) and maleic anhydride-modified styrene-ethylene / butene-styrene block copolymers are preferred.

[0073] Examples of butyl-based elastomers include isobutylene-isoprene copolymers (IIR) and their halides, styrene-isobutylene-styrene copolymers (SIBS) and their modifications, with styrene-isobutylene-styrene copolymers being preferred.

[0074] Examples of diene-based rubbers include natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR) (high cis BR and low cis BR), styrene-butadiene rubber (SBR) (emulsion polymerization SBR, solution polymerization SBR), chloroprene rubber (CR), nitrile rubber (NBR), epoxidized natural rubber, and their hydrides, but natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, and nitrile rubber are preferred.

[0075] Preferably, at least a portion of the elastomer is crosslinked. By crosslinking at least a portion of the elastomer, the decrease in the elastic modulus of the thermoplastic resin composition at high temperatures can be suppressed, resulting in excellent impact resistance of the thermoplastic resin composition at high temperatures. A method for crosslinking at least a portion of the elastomer can be exemplified by dynamic crosslinking, which involves adding a crosslinking agent capable of crosslinking the elastomer during the melt blending of the thermoplastic resin and the elastomer. As a crosslinking agent, a compound having multiple amino groups in one molecule is preferred, with diamines such as 3,3'-diaminodiphenyl sulfone (3,3'-DAS), 4,4'-diaminodiphenyl sulfone (4,4'-DAS), and N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD) being particularly preferred.

[0076] The dispersed phase may include elastomers other than olefin elastomers, styrene elastomers, butyl elastomers, diene rubbers and their modifiers, and various additives, without impairing the effects of the present invention.

[0077] The thermoplastic resin content in the thermoplastic resin composition constituting the inner layer is preferably 10-97% by mass of all polymer components in the thermoplastic resin composition, more preferably 15-95% by mass, and even more preferably 20-93% by mass. If the thermoplastic resin content is too low, it is difficult to suppress fluid permeation; if it is too high, the fatigue resistance at low temperatures is easily compromised.

[0078] The elastomer content in the thermoplastic resin composition constituting the inner layer is preferably 3 to 85% by mass of all polymer components in the thermoplastic resin composition, more preferably 5 to 80% by mass, and even more preferably 7 to 75% by mass. If the elastomer content is too low, the fatigue resistance at low temperatures is easily insufficient; if it is too high, it is difficult to suppress fluid permeation, and the impact pressure resistance at high temperatures is also difficult to balance.

[0079] The volume ratio of the continuous phase to the dispersed phase in the thermoplastic resin composition constituting the inner layer is preferably 95:5 to 25:75, more preferably 92:8 to 28:72, and even more preferably 90:10 to 30:70. By keeping the volume ratio of the continuous phase to the dispersed phase within the above-mentioned range, it is easy to achieve a balance between the fluid's impermeability, fatigue resistance at low temperatures, and impact pressure resistance at high temperatures.

[0080] The oxygen permeability coefficient of the thermoplastic resin composition constituting the inner layer at 21°C and 50% relative humidity is preferably 0.1 mm·cc / (m 2 Less than 0.00001 to 0.08 mm·cc / (m·day·mmHg), more preferably 0.00001 to 0.08 mm·cc / (m·day·mmHg). 2 (·day·mmHg), more preferably 0.0001~0.06mm·cc / (m 2 (·day·mmHg). By ensuring the oxygen permeability coefficient falls within this range, the thermoplastic resin composition can be used as the inner layer material for fluid transport hoses such as hydrogen hoses and air conditioning hoses. Methods for achieving this oxygen permeability coefficient include selecting the types of thermoplastic resin and elastomer, and adjusting the composition ratio.

[0081] The thermoplastic resin composition constituting the inner layer is exposed to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours. The ratio of the volume V at which the pressure is reduced to atmospheric pressure to the volume V0 before exposure, V / V0, is preferably less than 1.08, more preferably 1.00 to 1.07, and even more preferably 1.00 to 1.06. With V / V0 within this range, the dimensional change during decompression is small when transporting fluids with small molecular sizes such as hydrogen and helium at high pressure, which can suppress the generation of the failure initiation point caused by the inner layer sinking into the reinforcing layer.

[0082] When the thermoplastic resin composition constituting the inner layer is exposed to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours, the hydrogen dissolution rate is preferably 3000 ppm by mass or less, more preferably 2800 ppm by mass or less, and even more preferably 2600 ppm by mass or less. With the hydrogen dissolution rate within this range, fewer fluid molecules remain in the inner layer when transporting fluids with small molecular sizes such as hydrogen and helium under high pressure, thus suppressing damage caused by expansion within the inner layer during decompression.

[0083] The thermoplastic resin composition constituting the inner layer preferably fractures at a rate of 2 million or more, more preferably 2.5 million or more, and even more preferably 3 million or more, under repeated tensile stress at a temperature of -35°C, a strain of 18%, and a frequency of 6.7 Hz. By achieving this fracture count, the thermoplastic resin composition exhibits excellent fatigue resistance at low temperatures. Methods for achieving this fracture count include selecting appropriate types of thermoplastic resin and elastomer, adjusting the composition ratio, and adding components that enhance the interface between the thermoplastic resin and the elastomer.

[0084] The method of manufacturing the thermoplastic resin composition constituting the inner layer is not limited as long as the effects of the present invention are achieved. For example, it can be manufactured by melt-blending thermoplastic resin, elastomer, and crosslinking agent as needed.

[0085] The thickness of the inner layer is preferably 0.2 to 2.0 mm, more preferably 0.3 to 1.8 mm, and even more preferably 0.4 to 1.6 mm. If the inner layer is too thin, melt extrusion may become difficult or the extrusion method may be limited; if it is too thick, the flexibility of the hose may be insufficient and the operability may be poor.

[0086] The fluid transport hose includes a reinforcing layer disposed outside the inner layer. The reinforcing layer is a layer located between the inner and outer layers, and typically comprises a braided layer or a spiral layer formed by weaving together metal wire or organic fibers. Examples of metal wires include steel wire, copper and copper alloy wire, aluminum and aluminum alloy wire, magnesium alloy wire, titanium and titanium alloy wire, etc., but steel wire is preferred. The wire diameter of the metal wire is preferably 0.25 to 0.40 mm. Examples of organic fibers include poly(p-phenylenebenzodiphenylene oxide). PBO fiber, aramid fiber, carbon fiber, etc., are preferred, but PBO fiber is preferred. The diameter of the organic fiber is preferably 0.25-0.30 mm.

[0087] The reinforcing layer preferably comprises organic fibers or steel wires with a tensile modulus of elasticity of 100 GPa or higher. By including organic fibers or steel wires with a tensile modulus of elasticity of 100 GPa or higher in the reinforcing layer, the deformation of the hose is minimized even when high internal pressure is applied. More preferably, the tensile modulus of elasticity of the organic fibers or steel wires is 150 GPa or higher.

[0088] The fluid delivery hose includes an outer layer disposed outside the reinforcing layer.

[0089] The 10% modulus of the outer layer at 25°C is preferably 10 MPa or less, more preferably 0.1 to 9 MPa, and even more preferably 0.2 to 8 MPa. With a 10% modulus within this range, the outer layer is less prone to damage even during use due to friction and contact, and the bending stiffness is low, thus improving the operability of the hose.

[0090] The material constituting the outer layer is not limited, and examples include thermoplastic elastomers and vulcanized rubber, but thermoplastic elastomers are preferred. The thermoplastic elastomer is not limited, but polyester elastomers, polyamide elastomers, and polyurethane elastomers are preferred.

[0091] Polyester elastomers (TPEEs) are thermoplastic elastomers whose hard segments are polyester (e.g., polybutylene terephthalate) and whose soft segments are polyether (e.g., polybutanediol) or polyester (e.g., aliphatic polyester). Commercially available polyester elastomers are permitted, and such products can be used in this invention. Examples of commercially available polyester elastomers include "Perplen" (registered trademark) manufactured by Toyobo Co., Ltd., and "High-Terre" (registered trademark) manufactured by Tore Dupon Co., Ltd.

[0092] Polyamide elastomers (TPAs) are thermoplastic elastomers whose hard segments are polyamides (e.g., polyamide 6, polyamide 66, polyamide 11, polyamide 12) and whose soft segments are polyethers (e.g., polyethylene glycol, polypropylene glycol). Commercially available polyamide elastomers are permitted, and such products can be used in this invention. Examples of commercially available polyamide elastomers include the "UBESTA" (registered trademark) XPA series manufactured by Ube Industries, Ltd., and the "PEBAX" (registered trademark) manufactured by Alkema Co., Ltd.

[0093] Polyurethane elastomers are block copolymers composed of hard segments with urethane bonds and soft segments such as polyether, polyester, and polycarbonate. Commercially available polyurethane elastomers are also permitted in this invention. Examples of commercially available polyurethane elastomers include "Elastran" (registered trademark) manufactured by BASF, "Miractron" (registered trademark) manufactured by Nippon Miractron, and "Rezamin" (registered trademark) manufactured by Dainippon Seika Kogyo.

[0094] The thickness of the outer layer is preferably 0.2 to 1.2 mm, more preferably 0.3 to 1.0 mm, and even more preferably 0.4 to 0.8 mm. If the outer layer is too thin, it is easily damaged by friction, deformation, impact, etc. during operation of the hose, and may not be able to adequately protect the reinforcing layer. If it is too thick, the weight of the hose will increase and the operability will be poor.

[0095] There are no particular limitations on the manufacturing method of hoses for fluid transportation, and they can be manufactured as follows: The inner layer (inner tube) can be extruded into a tubular shape by extrusion molding, followed by weaving fibers into the tube to form a reinforcing layer, and then the outer layer (outer tube) can be coated onto the fibers by extrusion molding.

[0096] Example

[0097] [raw materials]

[0098] The raw materials used in the following embodiments and comparative examples are as follows.

[0099] (Inner layer made of thermoplastic resin)

[0100] PA11: Polyamide 11, manufactured by Alkema Co., Ltd. under the trademark "RILSAN" BESN OTL

[0101] PA12: Polyamide 12, manufactured by Ube Industries, Ltd. under the trademark "UBESTA" 3020U.

[0102] PA1010: Polyamide 1010, manufactured by "Tower" (registered trademark) "Tower" (registered trademark) made by "Tower"

[0103] PA610: Polyamide 610, Amiran Co., Ltd. (registered trademark) CM2001

[0104] PA6 / 12: Polyamide 6 / 12 copolymer, manufactured by Ube Industries, Ltd., "UBE Nailon" 7024B

[0105] PA6 / 66: Polyamide 6 / 66 copolymer, manufactured by Ube Industries, Ltd., under the brand name "UBE Nailon" 5023B.

[0106] PA6: Polyamide 6, "UBE Nailon" 1013B manufactured by Ube Kosan Co., Ltd.

[0107] EVOH: Ethylene-vinyl alcohol copolymer, manufactured by Mitsubishi Kemica Co., Ltd. under the trademark "Soarnol" (H4815B).

[0108] (Inner layer uses elastomer)

[0109] Acid-modified EBR-1: Maleic anhydride-modified ethylene-1-butene copolymer, manufactured by Mitsui Chemicals Co., Ltd., "Tafmar" (registered trademark) MH7010

[0110] Acid-modified EBR-2: Maleic anhydride-modified ethylene-1-butene copolymer, manufactured by Mitsui Chemicals Co., Ltd. (registered trademark) MH5020

[0111] Acid-modified SEBS: Maleic anhydride-modified styrene-ethylene / butene-styrene block copolymer, manufactured by Asahi Kasei Corporation, "Taftec" (registered trademark) M1943

[0112] Acid-modified SBS: Maleic anhydride-modified styrene-butadiene-styrene block copolymer, manufactured by Asahi Kasei Corporation, "Tafupren" (registered trademark) 912

[0113] Br-IPMS: Brominated isobutylene-p-methylstyrene copolymer, manufactured by Exson Mobil Kemical Co., Ltd., "EXXPRO" (registered trademark) 3745

[0114] (Cross-linking agent)

[0115] 3,3'-DAS: 3,3'-diaminodiphenyl sulfone, manufactured by Mitsui Chemicals Facility Co., Ltd.

[0116] 4,4'-DAS: 4,4'-diaminodiphenyl sulfone, manufactured by Mitsui Chemicals Facility Co., Ltd.

[0117] 6PPD: N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine, manufactured by Furususu Co., Ltd. (registered trademark)

[0118] (Outer layer material)

[0119] TPEE: Thermoplastic polyester elastomer, manufactured by Higashi Re Dupon Co., Ltd., "High-Temperature Elastomer" (registered trademark) 4057N (10% modulus at 25°C = 3.9 MPa)

[0120] (1) Preparation of thermoplastic resin composition

[0121] In a twin-screw compounding extruder (manufactured by Nippon Steel Corporation) with the barrel temperature set at 220°C, thermoplastic resin, elastomer, and crosslinking agent were introduced according to the formulations shown in Tables 1 to 3, and melt-blended for a residence time of approximately 5 minutes. The melt-blended compound was then extruded in strip form from a die installed at the discharge outlet. The resulting strip extrudate was granulated using a resin granulator to obtain a granulated thermoplastic resin composition.

[0122] (2) Fabrication of the hose

[0123] The granular thermoplastic resin composition prepared in step (1) above is extruded into a tube with an inner diameter of 9 mm and a thickness of 1 mm. This tube is used as the inner layer, and a braided layer of 3 layers of PBO fiber is woven on its outer side as a reinforcing layer. A braided layer of steel wire is further woven on its outer side. Furthermore, a thermoplastic polyester elastomer (manufactured by Higashi Re Dupon Co., Ltd., "High-Terrell" (registered trademark) 4057N) is extruded on the outer side of the reinforcing layer with a thickness of 0.7 mm to form a flexible tube.

[0124] Regarding the thermoplastic resin composition (inner layer material) prepared in step (1) above, the storage modulus (E') at -40°C was measured. L Storage modulus at 80℃ (E') H The oxygen permeability coefficient and fatigue resistance at low temperature (-35°C) were measured. For the thermoplastic polyester elastomer of the outer layer material, the 10% modulus was measured. For the hose made in (2) above, the impact pressure resistance at low temperature (-40°C) and high temperature (80°C) was evaluated. The results are shown in Tables 1 to 3.

[0125] In addition, the measurement / evaluation methods for each measurement / evaluation item are described below.

[0126] [Determination of the storage modulus E' of the thermoplastic resin composition (inner layer material)]

[0127] The granular thermoplastic resin composition prepared in step (1) above was used in a 40mmφ single screw extruder (Platinum Corporation) with a 550mm wide T-die. The temperature of the barrel and die was set to the melting point of the material with the highest melting point in the composition +20°C. The mixture was then molded into a sheet with an average thickness of 0.2mm under the conditions of a cooling roller temperature of 50°C and a traction speed of 3m / min.

[0128] The piece was cut into strips of a specified size, and the dynamic storage modulus was determined according to the method described in JIS K7198 under initial tension of 5%, frequency of 20 Hz, and dynamic strain of 0.1%.

[0129] [Determination of oxygen permeability coefficient of thermoplastic resin composition (inner layer material)]

[0130] Similar to the above [determination of the storage modulus E' of the thermoplastic resin composition (inner layer material), the thermoplastic resin composition (inner layer material) was molded into a sheet with an average thickness of 0.2 mm.

[0131] Cut the slice to the specified size and use MOCON's OXTRAN 1 / 50 to determine the oxygen permeability coefficient at 21°C and 50% relative humidity.

[0132] [Determination of the rate of volume change of the inner layer material due to hydrogen exposure]

[0133] The granular thermoplastic resin composition prepared in step (1) was extruded using a 40mm φ single-screw extruder (Platinum Corporation) with a 200mm wide T-die. The barrel and die temperatures were set to the melting point of the material with the highest melting point in the composition +20°C. The mixture was then formed into a sheet with an average thickness of 1.0mm at a cooling roller temperature of 50°C and a traction speed of 1m / min. The sheet was cut into discs with a diameter of 13mm and placed in a pressure vessel for 24 hours of hydrogen exposure at 30°C and 90MPa. After the pressure was reduced to just atmospheric pressure, the area of ​​the disc-shaped sample was measured using a Keyence TM-3000 2D multi-point dimension measuring instrument, and the volume change rate was calculated. As hydrogen was removed, the volume decreased. The volume change rate was calculated by dividing the maximum volume (maximum value) during the process by the volume before exposure, which was also measured. When the volume change rate is above 1.08, if hydrogen is repeatedly transported as a hose, the inner layer will sink into the reinforcement layer due to the volume change, resulting in reduced durability.

[0134] [Determination of hydrogen solubility in inner layer material due to hydrogen exposure]

[0135] Similar to the above [determination of volume change of inner layer material caused by hydrogen exposure], hydrogen was exposed at 30°C and 90 MPa for 24 hours. After depressurization to just atmospheric pressure, a disc was placed in a nitrogen-filled tube at 30°C. Gas was introduced into the tube from the end of the tube into the gas chromatograph at regular intervals to detect hydrogen that had escaped from the sample. The measurement was continued until no hydrogen was detected. The amount of hydrogen detected was accumulated to determine the amount of hydrogen dissolved into the sample through exposure.

[0136] [Determination of fatigue resistance at low temperatures of thermoplastic resin composition (inner layer material)]

[0137] Similar to the above [determination of the storage modulus E' of the thermoplastic resin composition (inner layer material)], a sheet with an average thickness of 0.2 mm was formed, and 20 strips with a width of 5 mm and a length of 200 mm were cut from the sheet. These strips were subjected to repeated tensile deformation using a constant strain constant load fatigue testing machine manufactured by Uejima Manufacturing Co., Ltd., under conditions of -35°C, 18% strain, and 6.7 Hz speed. The number of times that 12 out of the 20 strips (60%) broke was defined as the number of fractures. A higher number of fractures is more advantageous for repeated deformation at low temperatures and is preferred. Cases with fewer than 2 million fractures were judged as "unacceptable", cases with more than 2 million but less than 5 million fractures were judged as "good", and cases with more than 5 million fractures were judged as "excellent".

[0138] [Determination of 10% modulus of outer layer material]

[0139] The thermoplastic polyester elastomer of the outer layer material was extruded using a 40mmφ single-screw extruder (Platinum Corporation) with a 550mm wide T-die. The barrel and die temperatures were set to 230°C, and the material was formed into a sheet with an average thickness of 0.2mm under conditions of a cooling roller temperature of 50°C and a traction speed of 3m / min. The sheet was punched into a JIS No. 3 dumbbell shape and subjected to a tensile test according to JIS K6301 "Physical Test Method for Vulcanized Rubber" at 25°C and a tensile speed of 500mm / min. The stress at 10% tension (10% modulus) was determined from the obtained stress-strain curve.

[0140] [Evaluation of the impact pressure resistance of the hose]

[0141] According to JIS K6330-8 "Test Methods for Rubber and Resin Hoses - Part 8: Impact Pressure Test", the fluid is circulated in a U-shaped hose, and an impact waveform pressure of 90 MPa is applied at a frequency of 1 Hz and a pressure increase rate of 50 MPa / s until 100,000 cycles or the hose breaks. After the test, cases where no inner layer breaks are marked as 0, and cases where inner layer breaks are observed are marked as ×.

[0142] The test for impact resistance at low temperature (-40°C) was conducted using nitrogen gas cooled to -40°C as the fluid.

[0143] The test for impact resistance at high temperature (80°C) was conducted using oil at 80°C as the fluid.

[0144]

[0145]

[0146] Table 3

[0147]

[0148] Industry availability

[0149] The fluid delivery hose of the present invention can be used as a fluid delivery hose such as a hose for filling hydrogen from a distributor installed in a hydrogen station to a fuel cell vehicle, or a hose for delivering refrigerant to an air conditioner in a vehicle.

Claims

1. A flexible hose for fluid transport, characterized in that, It includes an inner layer formed of a thermoplastic resin composition comprising a thermoplastic resin and an elastomer, a reinforcing layer disposed outside the inner layer, and an outer layer disposed outside the reinforcing layer, wherein the storage modulus E' of the thermoplastic resin composition at -40°C is... L , and the energy storage modulus E' at 80℃ H Satisfying equations (1), (2) and (3), E’ L ≤ 1500MPa ···(1) AND' H ≥ 40MPa ···(2) AND' H / AND' L ≥ 0.05 ···(3), The storage modulus was measured according to the method described in JIS K7198, under initial tension of 5%, frequency of 20 Hz, and dynamic strain of 0.1%. The thermoplastic resin composition comprises a continuous phase containing a thermoplastic resin and a dispersed phase containing an elastomer, at least a portion of which is crosslinked.

2. The flexible hose for fluid transport according to claim 1, characterized in that, The oxygen permeability coefficient of the thermoplastic resin composition at 21°C and 50% relative humidity is 0.1 mm·cc / (m 2 (·day·mmHg) or less.

3. The fluid transport hose according to claim 1 or 2, characterized in that, The thermoplastic resin is selected from at least one of polyamide resins, vinyl alcohol resins, and polyester resins.

4. The fluid transport hose according to claim 1 or 2, characterized in that, The elastomer is selected from at least one of olefin elastomers, styrene elastomers, butyl elastomers, diene rubbers and their modifiers.

5. The fluid transport hose according to claim 1 or 2, characterized in that, The thermoplastic resin composition was exposed to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours. The ratio of the volume V when the pressure was reduced to atmospheric pressure to the volume V0 before exposure, V / V0, was less than 1.

08.

6. The fluid transport hose according to claim 1 or 2, characterized in that, The hydrogen solubility of the thermoplastic resin composition after exposure to a hydrogen atmosphere at 30°C and 90 MPa for 24 hours was less than 3000 ppm by mass.

7. The fluid transport hose according to claim 1 or 2, characterized in that, The thermoplastic resin composition fractures more than 2 million times under repeated tensile stress at a temperature of -35°C, a strain of 18%, and a frequency of 6.7 Hz.

8. The fluid transport hose according to claim 1 or 2, characterized in that, The outer layer has a 10% modulus of less than 10 MPa at 25°C. The 10% modulus at 25°C is the stress at 10% tension obtained from the stress-strain curve obtained by tensile testing at 25°C and a tensile speed of 500 mm / min.

9. The fluid transport hose according to claim 1 or 2, characterized in that, The reinforcing layer contains organic fibers or steel wires with a tensile modulus of elasticity of 100 GPa or higher.

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