# US 2010/0166995 A1 · Multilayer tube > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0166995 A1 - Document ID: US20100166995A1 - Status: Published application - Kind: A1 - Application number: 12/525,336 - Filed: 2008-01-31 - Published: 2010-07-01 - Earliest claimed: 2007-02-01 - Inventors: Masatomi Sato - Web page: https://patentgrep.com/patent/US20100166995A1 ## CPC - B32B 27/34: comprising polyamides - B32B 1/08: Tubular products - B32B 27/08: of synthetic resin - B32B 27/308: {comprising acrylic (co)polymers} - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - F16L 9/12: of plastics with or without reinforcement (F16L9/16 - F16L9/22 take precedence) - F16L 11/04: made of rubber or flexible plastics - B32B 2250/24: All layers being polymeric - B32B 2307/202: Conductive - B32B 2307/546: Flexural strength; Flexion stiffness - B32B 2307/7242: Non-permeable - B32B 2307/7265: Non-permeable - B32B 2597/00: Tubular articles, e.g. hoses, pipes - B32B 2605/08: Cars - Y10T 428/1393: Multilayer [continuous layer] - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract There is provided a multilayer resin tube having a plurality of thermoplastic resin layers, wherein an intermediate layer of the resin layers comprises an acid modified resin modified by the introduction of a functional group, and at least one layer is a barrier layer comprising an aromatic polyamide, for example, PA9T. The multilayer resin tube has good low-permeability attained with the use of an inexpensive resin, without using an expensive highly-functional resin such as a fluororesin. ## Claims ### Claim 1 A multilayer resin tube having a multilayer structure of a plurality of thermoplastic resin layers, wherein an intermediate layer of the plurality of resin layers comprises an acid modified resin modified by the introduction of a functional group, and at least one adjacent layer is a barrier layer comprising an aromatic polyamide as a main component. ### Claim 2 A multilayer resin tube having a multilayer structure of three or more thermoplastic resin layers, said tube having a barrier layer comprising an aromatic polyamide as a main component, wherein an outer layer and an inner layer, lying outside and inside the barrier layer, each comprise an acid modified resin modified by the introduction of a functional group. ### Claim 3 (depends on 2) The multilayer resin tube according to claim 2, wherein the barrier layer comprises PA9T. ### Claim 4 (depends on 3) The multilayer resin tube according to claim 3, wherein the outer layer and the inner layer each comprise an ethylene/GMA (glycidyl methacrylate) copolymer. ### Claim 5 A multilayer resin tube having a multilayer structure of three or more thermoplastic resin layers, said tube comprising a barrier layer comprising an acid modified aromatic polyamide, modified by the introduction of a functional group, as a main component, and an outer resin layer and an inner resin layer, both adjacent to the barrier layer. ### Claim 6 (depends on 5) The multilayer resin tube according to claim 5, wherein the barrier layer comprises acid modified PA9T. ### Claim 7 (depends on 3) The multilayer resin tube according to claim 3, wherein the outer resin layer and the inner resin layer each comprise PA6, PA66, PA11 or PA12, or a mixture thereof. ### Claim 8 (depends on 6) The multilayer resin tube according to claim 6, wherein the outer resin layer and the inner resin layer each comprise an acid modified PE resin. ### Claim 9 A multilayer resin tube having a multilayer structure of three or more thermoplastic resin layers, said tube having a layer comprising an acid modified resin modified by the introduction of a functional group, wherein an inner layer, lying inside the acid modified resin layer, is a barrier layer comprising an aromatic polyamide as a main component. ### Claim 10 (depends on 9) The multilayer resin tube according to claim 9, wherein the acid modified resin layer comprises an acid modified aromatic PA9T and the barrier layer comprises PA9T. ### Claim 11 (depends on 9) The multilayer resin tube according to claim 9, wherein the acid modified resin layer comprises an ethylene/GMA (glycidyl methacrylate) copolymer, and the barrier layer comprises PA9T or acid modified PA9T. ### Claim 12 (depends on 9) The multilayer resin tube according to claim 9, wherein the acid modified resin layer comprises acid modified polyethylene, and the barrier layer comprises acid modified PA9T. ### Claim 13 (depends on 10) The multilayer resin tube according to claim 10, wherein an outer layer, lying outside the acid modified resin layer, comprises PA6, PA66, PA11 or PA 12, or high-density polyethylene (HDPE), low-density polyethylene (LDPE) or linear low-density polyethylene. ### Claim 14 A multilayer resin tube having a multilayer structure of three or more thermoplastic resin layers, wherein a layer lying inside the outermost resin layer is a barrier layer comprising an acid modified aromatic polyamide, modified by the introduction of a functional group, as a main component. ### Claim 15 (depends on 10) The multilayer resin tube according to claim 10, wherein the outermost resin layer comprises PA6, PA66, PA11 or PA12, or a mixture thereof. ### Claim 16 (depends on 14) The multilayer resin tube according to claim 14, wherein the outermost resin layer comprises an ethylene/GMA (glycidyl methacrylate) copolymer. ### Claim 17 (depends on 10) The multilayer resin tube according to claim 10, wherein the outermost resin layer comprises an acid modified PE resin. ### Claim 18 A multilayer resin tube having a multilayer structure of three or more thermoplastic resin layers, wherein the outermost resin layer comprises an acid modified resin modified by the introduction of a functional group, and a layer lying inside the acid modified resin layer is a barrier layer comprising an aromatic polyamide as a main component. ### Claim 19 (depends on 18) The multilayer resin tube according to claim 18, wherein the outermost resin layer comprises an ethylene/GMA (glycidyl methacrylate) copolymer. ### Claim 20 A multilayer resin tube having a multilayer structure of five or more thermoplastic resin layers, wherein, in order from the outermost resin layer, the first layer is a PE (polyethylene) resin layer, the second and fourth layers are each an acid modified PE (polyethylene) resin layer, the resin being modified by the introduction of a functional group, and the third or fifth layer is a barrier layer comprising an aromatic polyamide. ### Claim 21 (depends on 1) The multilayer resin tube according to claim 1, wherein the innermost layer comprises a crosslinked polyethylene resin. ### Claim 22 (depends on 1) The multilayer resin tube according to claim 1, wherein the proportion of the acid modified resin(s) (excluding ethylene/GMA copolymer) in all the resins of the tube is less than 50% by weight. ### Claim 23 (depends on 8) The multilayer resin tube according to claim 8, wherein the acid modified PE resin has a tensile breaking strength of not less than 12 MPa, a breaking elongation of not less than 300% and an MFR of not less than 0.5 g/min. ### Claim 24 (depends on 1) The multilayer resin tube according to claim 1, wherein the resin (excluding PA) of the first layer has a density of 0.90 to 1.5 g/cm3, a flexural modulus of not less than 850 MPa and an environmental stress crack resistance of not less than 200 hr. ### Claim 25 (depends on 1) The multilayer resin tube according to claim 1, wherein the innermost layer is a conductive resin layer.