The present invention relates to a resin composition having gas barrier properties, which has excellent low-temperature characteristics and resistance to hydrogen brittleness without greatly detracting from gas barrier properties, and which can contribute to improve durability when used as a resin tube for high-pressure gas or as a resin liner for a composite container. Provided is an EVOH resin composition comprising: a fluororesin (A) having a functional group capable of interacting, or reacting, with a hydroxyl group; a thermoplastic resin (B) having a carboxyl group or an acid anhydride group (however, the fluororesin (A) and a saponified ethylene-vinyl ester copolymer (EVOH) having a carboxyl group or an acid anhydride group are excluded); and an EVOH (C).

Embodiments of the disclosure relate to a composition including 70 to 95 parts by weight of an epoxide resin having a viscosity of between 1 and 150 kPa.Math.s at a temperature of between 20 C. and 25 C., and 5 to 30 parts by weight, per 100 parts by weight of resin present in the composition, of a curing agent dispersed in the resin, the curing agent being an ionic liquid containing a phosphonium cation. The disclosure also relates to a semi-finished product or towpreg, including a bundle of fibres and a composition. The disclosure also relates to the use of a composition or of a semi-finished product according to the disclosure for the production of a hydrogen tank, in particular a type IV pressure tank, made of composite material, for the on-board storage of hydrogen gas.

Provided is a prepreg in which gas barrier properties in a case of being molded into a molded product are improved. In the prepreg of the present invention, a thermoplastic resin with which a carbon fiber base material is impregnated, and the thermoplastic resin comprises a vinyl alcohol-based polymer.

The present invention relates to a multilayer structure for storing or transporting a gas comprising hydrogen, wherein the multilayer structure comprises at least three layers comprising an inner layer comprising at least one first polymer, a middle layer comprising ethylene-vinyl alcohol copolymer, and an outer layer comprising at least one second polymer, and wherein the water-vapour transmission rate of the inner layer is lower than that of the outer layer. The multilayer structure has excellent hydrogen gas barrier properties. Therefore, the multilayer structure is suitable for a hydrogen storage vessel and a hydrogen transportation pipe.

Provided is an epoxy resin composition containing an epoxy resin (A), an epoxy resin curing agent (B) containing a phenolic curing agent, and a curing accelerator (C),

wherein the epoxy resin (A) contains from 10 to 85 mass % of an epoxy resin (A1) and from 15 to 90 mass % of an epoxy resin (A2), the epoxy resin (A1) having a glycidyloxy group derived from resorcinol, and the epoxy resin (A2) being other than the epoxy resin (A1) and containing an aromatic ring,

the epoxy resin (A2) contains at least one type selected from the group consisting of an epoxy resin (a2-1) having a glycidyloxy group derived from bisphenol F. and an epoxy resin (a2-2) having a glycidyloxy group derived from a polyol having a naphthalene backbone, and

a total content of the epoxy resin (a2-1) and the epoxy resin (a2-2) in the epoxy resin (A2) is 50 mass % or more. Also provided are a cured product of the epoxy resin composition, a prepreg using the epoxy resin composition, a fiber-reinforced composite material and a high-pressure gas container.

Provided is an epoxy resin composition containing an epoxy resin (A) and an epoxy resin curing agent (B), wherein the epoxy resin (A) contains from 10 to 65 mass % of an epoxy resin (A1) and from 35 to 90 mass % of an epoxy resin (A2), the epoxy resin (A1) having a glycidyloxy group derived from resorcinol, and the epoxy resin (A2) being other than the epoxy resin (A1) and containing an aromatic ring; the epoxy resin (A2) contains 70 mass % or more of an epoxy resin having a glycidyloxy group derived from bisphenol F; and a cured product of the epoxy resin composition has a hydrogen gas permeability coefficient of 6.410.sup.11 or less [cc.Math.cm/(cm.sup.2.Math.s.Math.cmHg)]. Also provided are a cured product of the epoxy resin composition, a fiber-reinforced composite material, and a high-pressure gas container containing the fiber-reinforced composite material.

A tank comprising a multi-layer structure, for storing compressed gas, including in succession from inside to outside at least the three following layers: at least one sealing layer of a composition including at least one semi-crystalline thermoplastic polyamide having a Tm of less than or equal to 280 C., at least one intermediate composite reinforcing layer of a fibrous material in the form of continuous fibres impregnated with a composition including at least one semi-crystalline thermoplastic polyamide having a Tg of less than 100 C., at least one outer composite reinforcing layer of a fibrous material in the form of continuous fibres impregnated with a composition including at least one polyphthalamide having a Tg of greater than 80 C., the outermost sealing layer being welded to the innermost intermediate composite reinforcing layer and the outermost intermediate composite reinforcing layer being welded to the innermost outer composite reinforcing layer.

A polyamide resin composition for a molded article exposed to high-pressure hydrogen contains a polyamide 6 resin (A) and a polyamide resin (B) having a melting point, as determined by DSC, that is not higher than a melting point of the polyamide 6 resin (A) +20 C. and a cooling crystallization temperature, as determined by DSC, that is higher than a cooling crystallization temperature of the polyamide 6 resin (A), the polyamide resin (B) present in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the polyamide 6 resin (A). The polyamide resin composition can provide a molded article having excellent weld properties and is less likely to suffer failure points despite repeated charging and discharging of high-pressure hydrogen.

The invention relates to a polyamide composition comprising: a. A semi-crystalline polyamide; b. An impact modifier in an amount ranging from 1 wt % to 50 wt %; c. A branching agent in an amount ranging from 0.01 to 6.0 wt %; d. An inorganic stabilizer in an amount ranging from 0.01 wt % to 2.0 wt %; e. An organic stabilizer E1 comprising a primary antioxidant group in an amount ranging from 0.01 wt % to 2.0 wt and an organic stabilizer E2 comprising a hindered amine group in an amount ranging from 0.01 wt % to 4.0 wt %; or an organic stabilizer E3 comprising a primary antioxidant group and a hindered amine group in an amount ranging from 0.02 to 6.0 wt %; or a combination of E1, E2 and E3 in a total amount of 0.02 to 6.0 wt %; wherein all wt % are based on the total amount of polyamide composition. The invention also relates to a process for preparing a container by blow molding this composition, as well as use of the container in various applications.

A tank for safely storing a fuel in a high-pressure gaseous state, and a method for manufacturing the tank are provided. The fuel gas storage tank includes a composite material that forms a tank shell and a liner disposed under the composite material. In addition, the liner has a structure in which a metal coil is integrally formed within the liner.