A crosslinked modified tritium permeation resistant composite material and a method of making the same

Abstract

The application discloses a crosslinking modified anti-tritium permeation composite material and a preparation method thereof, and belongs to the technical field of anti-tritium composite materials. The crosslinking modified anti-tritium permeation composite material comprises, from outside to inside, a protective layer, a barrier layer and a heat sealing layer. The protective layer comprises TPEE elastomer, high-density polyethylene resin, maleic anhydride grafted polyethylene resin, EVA resin, antioxidant and rare earth oxide. The TPEE elastomer, the high-density polyethylene resin, the maleic anhydride grafted polyethylene resin and the EVA resin are crosslinked with each other. The barrier layer is selected from PVDC resin with a MA content of 5wt%-10wt%. The heat sealing layer is selected from EVA resin with a VA content of 10wt%-20wt%. The crosslinking modified anti-tritium permeation composite material has low tritium permeation rate, excellent tensile strength, tear strength and interlayer bonding performance.

Description

Technical Field

[0001] This invention relates to the technical field of tritium-resistant composite materials, and more particularly to a cross-linked modified tritium-resistant composite material and its preparation method. Background Technology

[0002] Tritium is a low-energy beta emitter with very high specific activity, belonging to the category of low-toxicity but difficult-to-protect-from radioactive nuclides. The main radiation hazards of tritium come from internal radiation hazards caused by direct inhalation and skin absorption. Regarding personal safety protection against tritium, tritium glove boxes and tritium protective clothing are the primary protective equipment. They can reduce the penetration and harm of tritium into the human body to a certain extent and play an irreplaceable role in tritium processes and tritium protection.

[0003] When selecting tritium-protective clothing, the permeability of the materials is a primary consideration. Tritium-protective clothing made from polymers such as vulcanized rubber, celluloid, polyvinyl chloride, and polyethylene cannot meet the performance requirements due to the high permeability of tritium in these materials. Therefore, there is an urgent need to develop a new type of tritium-permeable composite material to meet the performance requirements of high-performance tritium-protective clothing, which is of significant practical importance for the application of tritium-protective clothing. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a cross-linked modified tritium-permeable barrier composite material and its preparation method. The cross-linked modified tritium-permeable barrier composite material has the characteristics of good heat-sealing properties, low tritium permeability, and good resistance to chemical penetration.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] This invention provides a cross-linked modified tritium-impermeable composite material, which consists of a protective layer, a barrier layer, and a heat-sealing layer from the outside to the inside.

[0007] Preferably, the protective layer of the present invention comprises, by weight, the following components:

[0008] TPEE elastomer: 30-50 parts;

[0009] High-density polyethylene resin: 20-40 parts;

[0010] Maleic anhydride-grafted polyethylene resin: 3-5 parts;

[0011] EVA resin: 10-20 parts;

[0012] Antioxidant: 0.5-1 part;

[0013] Rare earth oxides: 1-2 parts;

[0014] Sensitizer: 1-2 parts.

[0015] Preferably, the molecular chains of the TPEE elastomer, high-density polyethylene resin, maleic anhydride-grafted polyethylene resin, and EVA resin are cross-linked.

[0016] Preferably, the barrier layer is selected from PVDC resin with a methyl acrylate content of 5wt%-10wt%.

[0017] Preferably, the heat-sealing layer is selected from EVA resin with a vinyl acetate content of 10wt%-20wt%.

[0018] This invention improves the tensile strength and tear strength of the crosslinked modified tritium-permeable composite material by physically modifying and irradiating the protective layer for crosslinking.

[0019] Sensitizers were introduced into the physical modification of the protective layer.

[0020] The sensitizer can achieve cross-linking between the molecular chains of TPEE elastomer, high-density polyethylene resin, and maleic anhydride-grafted polyethylene resin in the protective layer under low radiation doses.

[0021] Preferably, the total thickness of the crosslinked modified tritium-permeable composite material is 0.15-0.2 mm; more preferably, it is 0.15 mm or 0.2 mm.

[0022] Preferably, the thickness of the protective layer is 35%-40% of the total thickness of the cross-linked modified tritium-permeable composite material; more preferably, it is 35% or 40%.

[0023] Preferably, the thickness of the barrier layer is 20%-30% of the total thickness of the cross-linked modified tritium-permeable composite material; more preferably, it is 20% or 30%.

[0024] Preferably, the thickness of the heat-sealing layer is 35%-40% of the total thickness of the cross-linked modified tritium-permeable composite material; more preferably, it is 35% or 40%.

[0025] In some specific embodiments of the present invention, the total thickness of the protective layer / barrier layer / heat-sealing layer is 0.2 mm, and the thicknesses of the protective layer, barrier layer, and heat-sealing layer are 0.07 mm, 0.06 mm, and 0.07 mm, respectively.

[0026] In some specific embodiments of the present invention, the total thickness of the protective layer / barrier layer / heat-sealing layer is 0.15 mm, and the thicknesses of the protective layer, barrier layer, and heat-sealing layer are 0.06 mm, 0.03 mm, and 0.06 mm, respectively.

[0027] Preferably, the melt index of the TPEE elastomer is 5-10 g / 10 min; more preferably, it is 5 g / 10 min or 10 g / 10 min.

[0028] Preferably, the melt index of the high-density polyethylene resin is 2-5 g / 10 min; more preferably, it is 2 g / 10 min or 5 g / 10 min.

[0029] Preferably, the melt index of the maleic anhydride-grafted polyethylene resin is 2-10 g / 10 min; more preferably, it is 2 g / 10 min or 10 g / 10 min. Preferably, the antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, dilauryl thiodipropionate, and tris(2,4-di-tert-butyl)phosphite.

[0030] Preferably, the rare earth oxide is selected from one or more of cerium oxide, gadolinium oxide, and erbium oxide.

[0031] Preferably, the sensitizer is selected from one or more of triallyl isocyanurate, trimethylolpropane trimethacrylate, and diphenylmethane bismaleimide.

[0032] More preferably, the protective layer of the present invention comprises, by weight, the following components:

[0033] TPEE elastomer: 30 parts;

[0034] High-density polyethylene resin: 40 parts;

[0035] Maleic anhydride-grafted polyethylene resin: 5 parts;

[0036] EVA resin: 20 parts;

[0037] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 1 part;

[0038] Cerium oxide: 2 parts;

[0039] Triallyl isocyanurate: 2 parts;

[0040] The barrier layer is selected from PVDC resin with a methyl acrylate (MA) content of 10 wt%.

[0041] The heat-sealing layer is selected from EVA resin with a vinyl acetate (VA) content of 20 wt%.

[0042] More preferably, the protective layer comprises, by weight, the following components:

[0043] 30 parts of TPEE elastomer with a melt index of 5 g / min;

[0044] High-density polyethylene resin with a melt index of 2 g / 10 min: 40 parts;

[0045] Maleic anhydride-grafted polyethylene resin with a melt index of 2 g / 10 min: 5 parts;

[0046] EVA resin with a vinyl acetate content of 20 wt%: 20 parts;

[0047] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 1 part;

[0048] Cerium oxide: 2 parts;

[0049] Triallyl isocyanurate: 2 parts;

[0050] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0051] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%. More preferably, the protective layer, by weight, comprises the following components:

[0052] TPEE elastomer: 40 parts;

[0053] High-density polyethylene resin: 30 parts;

[0054] Maleic anhydride-grafted polyethylene resin: 4 parts;

[0055] EVA resin: 15 parts;

[0056] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 0.75 parts;

[0057] Cerium oxide: 1.5 parts;

[0058] Triallyl isocyanurate: 1.5 parts;

[0059] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0060] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0061] More preferably, the protective layer comprises, by weight, the following components:

[0062] 40 parts of TPEE elastomer with a melt index of 5 g / min;

[0063] 30 parts of high-density polyethylene resin with a melt index of 2 g / 10 min;

[0064] Maleic anhydride-grafted polyethylene resin with a melt index of 2 g / 10 min: 4 parts;

[0065] 15 parts of EVA resin with a vinyl acetate content of 20 wt%;

[0066] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 0.75 parts;

[0067] Cerium oxide: 1.5 parts;

[0068] Triallyl isocyanurate: 1.5 parts;

[0069] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0070] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%. More preferably, the protective layer, by weight, comprises the following components:

[0071] TPEE elastomer: 50 parts;

[0072] High-density polyethylene resin: 20 parts;

[0073] Maleic anhydride-grafted polyethylene resin: 3 parts;

[0074] EVA resin: 10 parts;

[0075] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 0.5 parts;

[0076] Cerium oxide: 1 part;

[0077] Triallyl isocyanurate: 1 part;

[0078] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0079] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0080] More preferably, the protective layer comprises, by weight, the following components:

[0081] 50 parts of TPEE elastomer with a melt index of 5 g / min;

[0082] 20 parts of high-density polyethylene resin with a melt index of 2 g / 10 min;

[0083] Maleic anhydride-grafted polyethylene resin with a melt index of 2 g / 10 min: 3 parts;

[0084] 10 parts of EVA resin with a vinyl acetate content of 20 wt%;

[0085] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester: 0.5 parts;

[0086] Cerium oxide: 1 part;

[0087] Triallyl isocyanurate: 1 part;

[0088] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0089] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%. More preferably, the protective layer, by weight, comprises the following components:

[0090] TPEE elastomer: 30 parts;

[0091] High-density polyethylene resin: 40 parts;

[0092] Maleic anhydride-grafted polyethylene resin: 5 parts;

[0093] EVA resin: 20 parts;

[0094] Dilauryl thiodipropionate: 1 part;

[0095] Gadolinium oxide: 2 parts;

[0096] Trimethylolpropane trimethacrylate: 2 parts;

[0097] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0098] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0099] More preferably, the protective layer comprises, by weight, the following components:

[0100] 30 parts of TPEE elastomer with a melt index of 10 g / min;

[0101] High-density polyethylene resin with a melt index of 5 g / 10 min: 40 parts;

[0102] Maleic anhydride-grafted polyethylene resin with a melt index of 10 g / 10 min: 5 parts;

[0103] EVA resin with 10wt% vinyl acetate content: 20 parts;

[0104] Dilauryl thiodipropionate: 1 part;

[0105] Gadolinium oxide: 2 parts;

[0106] Trimethylolpropane trimethacrylate: 2 parts;

[0107] The barrier layer is selected from PVDC resin with a methyl acrylate content of 10 wt%.

[0108] The heat-sealing layer is selected from EVA resin with a vinyl acetate content of 20 wt%. This invention also provides a method for preparing a cross-linked modified tritium-permeable barrier composite material, comprising the following steps:

[0109] 1) Mix TPEE elastomer, high-density polyethylene, maleic anhydride grafted polyethylene, EVA resin, antioxidant, rare earth oxide and sensitizer, extrude and granulate to obtain modified resin.

[0110] 2) The modified resin obtained above, a PVDC resin membrane with a methyl acrylate content of 5wt%-10wt%, and an EVA resin with a vinyl acetate content of 10wt%-20wt% are extruded to obtain a modified resin membrane, a PVDC resin membrane, and an EVA resin membrane, respectively. These are then stacked sequentially and crosslinked by irradiation to prepare a crosslinked modified tritium permeation-proof composite material.

[0111] The above preparation method yielded the crosslinked modified tritium-permeable composite material of the present invention through multilayer co-extrusion and irradiation crosslinking.

[0112] Preferably, the extrusion temperature in step 1) of the present invention is 180℃-220℃; more preferably, it is 180℃ or 220℃.

[0113] Preferably, the screw speed of the extrusion is 50-70 rpm / min; more preferably, it is 50 rpm / min or 70 rpm / min.

[0114] In the above preparation method, the extrusion temperature of the modified resin film in step 2) is preferably 180℃-220℃, and the screw speed is preferably 25-35r / min.

[0115] In some specific embodiments of the present invention, the extrusion temperature of the modified resin film is 180°C, and the screw speed is preferably 35 r / min.

[0116] In some specific embodiments of the present invention, the extrusion temperature of the modified resin film is 220°C, and the screw speed is preferably 25 r / min.

[0117] The extrusion temperature of the PVDC resin film in step 2) is preferably 170℃-190℃, and the screw speed is preferably 15-20r / min.

[0118] In some specific embodiments of the present invention, the extrusion temperature of the PVDC resin film is 170°C, and the screw speed is preferably 15 r / min.

[0119] In some specific embodiments of the present invention, the extrusion temperature of the PVDC resin film is 190°C, and the screw speed is preferably 20 r / min.

[0120] The extrusion temperature of the EVA resin film in step 2) is preferably 170℃-210℃, and the screw speed is preferably 25-35r / min.

[0121] In some specific embodiments of the present invention, the extrusion temperature of the EVA resin film is 170°C, and the screw speed is preferably 35 r / min.

[0122] In some specific embodiments of the present invention, the extrusion temperature of the EVA resin film is 210°C, and the screw speed is preferably 25 r / min.

[0123] More preferably, the irradiation dose in step 2) of the present invention is 30-50 kGy. In some specific embodiments of the present invention, the irradiation dose in step 2) is 30 kGy or 50 kGy.

[0124] In step 2), the film blank is obtained after lamination.

[0125] After lamination, the resulting film preform is cooled, stretched, and wound up.

[0126] Then, irradiation treatment is performed to cause TPEE elastomer, high-density polyethylene resin, and maleic anhydride grafted polyethylene resin in the modified resin to undergo irradiation crosslinking, thereby causing the molecular chains of TPEE elastomer, high-density polyethylene resin, and maleic anhydride grafted polyethylene resin to crosslink with each other.

[0127] The present invention also provides a tritium permeation prevention device, comprising the above-mentioned cross-linked modified tritium permeation prevention composite material or the cross-linked modified tritium permeation prevention composite material prepared by the above-mentioned preparation method.

[0128] The tritium penetration protection equipment includes, but is not limited to, protective clothing and protective gloves.

[0129] Compared with existing technologies, the cross-linked modified tritium-permeable composite material provided by this invention consists of a protective layer, a barrier layer, and a heat-sealing layer from the outside in. The protective layer, by weight, comprises the following components: TPEE elastomer: 30-50 parts, high-density polyethylene resin: 20-40 parts, maleic anhydride-grafted polyethylene resin: 3-5 parts, EVA resin: 10-20 parts, antioxidant: 0.5-1 part, rare earth oxide: 1-2 parts, and sensitizer: 1-2 parts. The molecular chains of the TPEE elastomer, high-density polyethylene resin, maleic anhydride-grafted polyethylene resin, and EVA resin in the protective layer are cross-linked. The barrier layer is selected from PVDC resin with a methyl acrylate content of 5wt%-10wt%, and the heat-sealing layer is selected from EVA resin with a vinyl acetate content of 10wt%-20wt%. The cross-linked modified tritium-permeable composite material of this invention exhibits low tritium permeability and excellent tensile strength, tear strength, and interlayer bonding performance. It has broad application prospects in the preparation of tritium protective clothing. Detailed Implementation

[0130] To further illustrate the present invention, the following detailed description of the crosslinked modified tritium-permeable composite material and its preparation method provided by the present invention is provided in conjunction with embodiments.

[0131] The raw materials used in the preparation of the crosslinked modified tritium-permeable composite material described below are all commercially available products.

[0132] Example 1

[0133] (1) Preparation of protective layer with modified resin

[0134] 30 parts of TPEE elastomer with a melt index of 5 g / min, 40 parts of high-density polyethylene with a melt index of 2 g / 10 min, 5 parts of maleic anhydride grafted polyethylene with a melt index of 2 g / 10 min, 20 parts of EVA resin with a vinyl acetate content of 20%, 1 part of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, 2 parts of cerium oxide, and 2 parts of triallyl isocyanurate.

[0135] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 400 rpm / min, the dispersion speed at 800 rpm / min, and the stirring time at 10 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 220℃ and a screw speed controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0136] (2) Preparation of cross-linked modified tritium-impermeable composite materials

[0137] Modified resin for the protective layer, PVDC resin with 10% MA (methyl acrylate) content, and EVA resin with 20% vinyl acetate content were added to three single-screw extruders A, B, and C in the co-extrusion molding unit, respectively. The die temperature of single-screw extruder A was 220℃, and the screw speed was 25 r / min; the die temperature of single-screw extruder B was 190℃, and the screw speed was 20 r / min; the die temperature of single-screw extruder C was 210℃, and the screw speed was 25 r / min. The polymer melt was extruded into the die head through the corresponding extruders for lamination to obtain a preform. The preform was cooled, stretched, and wound to obtain a 0.2 mm thick tritium-impermeable composite material (thickness ratio 35% / 30% / 35%).

[0138] The tritium-impermeable composite material was irradiated with an electron beam accelerator at a dose of 50 kGy to obtain a cross-linked modified tritium-impermeable composite material.

[0139] Example 2

[0140] (1) Preparation of protective layer with modified resin

[0141] 40 parts of TPEE elastomer with a melt index of 5 g / min, 30 parts of high-density polyethylene with a melt index of 2 g / 10 min, 4 parts of maleic anhydride-grafted polyethylene with a melt index of 2 g / 10 min, 15 parts of EVA resin with a vinyl acetate content of 20%, 0.75 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1.5 parts of cerium oxide, and 1.5 parts of triallyl isocyanurate.

[0142] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 400 rpm / min, the dispersion speed at 800 rpm / min, and the stirring time at 10 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 220℃ and a screw speed controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0143] (2) Preparation of cross-linked modified tritium-impermeable composite materials

[0144] Modified resin for the protective layer, PVDC resin with 10% MA (methyl acrylate) content, and EVA resin with 20% vinyl acetate content were added to three single-screw extruders A, B, and C in the co-extrusion molding unit, respectively. The die temperature of single-screw extruder A was 220℃, and the screw speed was 25 r / min; the die temperature of single-screw extruder B was 190℃, and the screw speed was 20 r / min; the die temperature of single-screw extruder C was 210℃, and the screw speed was 25 r / min. The polymer melt was extruded into the die head through the corresponding extruders for lamination to obtain a preform. The preform was cooled, stretched, and wound to obtain a 0.2 mm thick tritium-impermeable composite material (thickness ratio 35% / 30% / 35%).

[0145] The tritium-impermeable composite material was irradiated with an electron beam accelerator at a dose of 50 kGy to obtain a cross-linked modified tritium-impermeable composite material.

[0146] Example 3

[0147] (1) Preparation of protective layer with modified resin

[0148] 50 parts of TPEE elastomer with a melt index of 5 g / min, 20 parts of high-density polyethylene with a melt index of 2 g / 10 min, 3 parts of maleic anhydride-grafted polyethylene with a melt index of 2 g / 10 min, 10 parts of EVA resin with a vinyl acetate content of 20%, 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, 1 part of cerium oxide, and 1 part of triallyl isocyanurate.

[0149] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 400 rpm / min, the dispersion speed at 800 rpm / min, and the stirring time at 10 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 220℃ and a screw speed controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0150] (2) Preparation of cross-linked modified tritium-impermeable composite materials

[0151] Modified resin for the protective layer, PVDC resin with 10% MA (methyl acrylate) content, and EVA resin with 20% vinyl acetate content were added to three single-screw extruders A, B, and C in the co-extrusion molding unit, respectively. The die temperature of single-screw extruder A was 220℃, and the screw speed was 25 r / min; the die temperature of single-screw extruder B was 190℃, and the screw speed was 20 r / min; the die temperature of single-screw extruder C was 210℃, and the screw speed was 25 r / min. The polymer melt was extruded into the die head through the corresponding extruders for lamination to obtain a preform. The preform was cooled, stretched, and wound to obtain a 0.2 mm thick tritium-impermeable composite material (thickness ratio 35% / 30% / 35%).

[0152] The tritium-impermeable composite material was irradiated with an electron beam accelerator at a dose of 50 kGy to obtain a cross-linked modified tritium-impermeable composite material.

[0153] Example 4

[0154] (1) Preparation of protective layer with modified resin

[0155] 30 parts of TPEE elastomer with a melt index of 10 g / min, 40 parts of high-density polyethylene with a melt index of 5 g / 10 min, 5 parts of maleic anhydride grafted polyethylene with a melt index of 10 g / 10 min, 20 parts of EVA resin with a vinyl acetate content of 10%, 1 part of dilaurate thiodipropionate, 2 parts of gadolinium oxide, and 2 parts of trimethylolpropane trimethacrylate.

[0156] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 200 rpm / min, the dispersion speed at 500 rpm / min, and the stirring time at 5 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 180℃ and a screw speed controlled at 50 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0157] (2) Preparation of cross-linked modified tritium-impermeable composite materials

[0158] In a co-extrusion molding unit, three single-screw extruders A, B, and C were respectively equipped with a modified resin for the protective layer, PVDC resin with 5% MA (methyl acrylate) content, and EVA resin with 10% vinyl acetate content. The die temperature of single-screw extruder A was 180℃, and the screw speed was 35 r / min; the die temperature of single-screw extruder B was 170℃, and the screw speed was 15 r / min; the die temperature of single-screw extruder C was 170℃, and the screw speed was 35 r / min. The polymer melt was extruded into the die head through the corresponding extruders for lamination to obtain a preform. The preform was cooled, stretched, and wound to obtain a 0.15 mm thick tritium-impermeable composite material (thickness ratio 40% / 20% / 40%).

[0159] The tritium-impermeable composite material was irradiated with an electron beam accelerator at a dose of 30 kGy to obtain a crosslinked modified tritium-impermeable composite material.

[0160] Example 5

[0161] (1) Preparation of protective layer with modified resin

[0162] 30 parts of TPEE elastomer with a melt index of 10 g / min, 40 parts of high-density polyethylene with a melt index of 5 g / 10 min, 5 parts of maleic anhydride-grafted polyethylene with a melt index of 10 g / 10 min, 20 parts of EVA resin with a vinyl acetate content of 10%, 1 part of tris(2,4-di-tert-butyl) phosphite, 2 parts of erbium oxide, and 2 parts of diphenylmethane bismaleimide.

[0163] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 200 rpm / min, the dispersion speed at 500 rpm / min, and the stirring time at 5 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 180℃ and a screw speed controlled at 50 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0164] (2) Preparation of cross-linked modified tritium-impermeable composite materials

[0165] In a co-extrusion molding unit, three single-screw extruders A, B, and C were respectively equipped with a modified resin for the protective layer, PVDC resin with 5% MA (methyl acrylate) content, and EVA resin with 10% vinyl acetate content. The die temperature of single-screw extruder A was 180℃, and the screw speed was 35 r / min; the die temperature of single-screw extruder B was 170℃, and the screw speed was 15 r / min; the die temperature of single-screw extruder C was 170℃, and the screw speed was 35 r / min. The polymer melt was extruded into the die head through the corresponding extruders for lamination to obtain a preform. The preform was cooled, stretched, and wound to obtain a 0.15 mm thick tritium-impermeable composite material (thickness ratio 40% / 20% / 40%).

[0166] The tritium-impermeable composite material was irradiated with an electron beam accelerator at a dose of 30 kGy to obtain a crosslinked modified tritium-impermeable composite material.

[0167] Comparative Example 1

[0168] (1) Preparation of protective layer with modified resin

[0169] 30 parts of TPEE elastomer with a melt index of 5 g / min, 40 parts of high-density polyethylene with a melt index of 2 g / 10 min, 5 parts of maleic anhydride grafted polyethylene with a melt index of 2 g / 10 min, 20 parts of EVA resin with a vinyl acetate content of 20%, 1 part of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester, and 2 parts of cerium oxide.

[0170] Weigh the raw materials according to the above proportions and pour them into a mixer. Control the stirring speed at 400 rpm / min, the dispersion speed at 800 rpm / min, and the stirring time at 10 min. After mixing evenly, add the above raw materials to a twin-screw extruder at a temperature controlled at 220℃ and a screw speed controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0171] (2) Preparation of uncrosslinked modified tritium-permeable composite material

[0172] Modified resin for the protective layer, PVDC resin with 10% MA (methyl acrylate) content, and EVA resin with 20% vinyl acetate content were added to three single-screw extruders A, B, and C in the co-extrusion molding unit, respectively. The die temperature of single-screw extruder A was 220℃, and the screw speed was 25 r / min; the die temperature of single-screw extruder B was 190℃, and the screw speed was 20 r / min; the die temperature of single-screw extruder C was 210℃, and the screw speed was 25 r / min. The polymer melt was extruded into the die head of the corresponding extruder for stacking to obtain a preform. The preform was cooled, stretched, and wound to obtain a comparative sample 1 with a thickness of 0.2 mm (thickness ratio of 35% / 30% / 35%).

[0173] Comparative Example 2

[0174] TPEE elastomer with a melt index of 5 g / min, PVDC resin with 10% MA (methyl acrylate) content, and EVA resin with 20% vinyl acetate content were added to three single-screw extruders A, B, and C in a co-extrusion molding unit, respectively. The die temperature of single-screw extruder A was 220℃, and the screw speed was 25 r / min; the die temperature of single-screw extruder B was 190℃, and the screw speed was 20 r / min; the die temperature of single-screw extruder C was 210℃, and the screw speed was 25 r / min. The polymer melt was extruded into the die head through the corresponding extruder for stacking to obtain a preform. The preform was cooled, stretched, and wound to obtain a comparative sample 2 with a thickness of 0.2 mm (thickness percentages of 35% / 30% / 35%).

[0175] The performance of the crosslinked modified tritium-permeable composite materials prepared in Examples 1-5 and Comparative Examples 1-2 was tested, and the test results are shown in Table 1.

[0176] Table 1. Performance test results of cross-linked modified tritium-permeable composite materials

[0177]

[0178] Note: All test samples were tested after being irradiated with a dose of 30 kGy.

[0179] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A crosslinked modified tritium permeation resistant composite material, characterized in that, The protective layer, the barrier layer and the heat-sealing layer are sequentially arranged from outside to inside. The protective layer comprises the following components by weight: TPEE elastomer: 30-50 parts; High-density polyethylene resin: 20-40 parts; Maleic anhydride grafted polyethylene resin: 3-5 parts; EVA resin: 10-20 parts; Antioxidant: 0.5-1 part; Rare earth oxide: 1-2 parts; Sensitizer: 1-2 parts; The molecular chains of the TPEE elastomer, the high-density polyethylene resin, the maleic anhydride grafted polyethylene resin and the EVA resin are crosslinked with each other; The barrier layer is selected from a PVDC resin with a methyl acrylate content of 5wt%-10wt%; The heat-sealing layer is selected from an EVA resin with a vinyl acetate content of 10wt%-20wt%.

2. The crosslinking modified, tritium impermeable composite of claim 1, wherein, The total thickness of the crosslinked modified anti-tritium permeation composite material is 0.15-0.2 mm; The thickness of the protective layer is 35%-40% of the total thickness of the crosslinked modified anti-tritium permeation composite material; The thickness of the barrier layer is 20%-30% of the total thickness of the crosslinked modified anti-tritium permeation composite material; The thickness of the heat-sealing layer is 35%-40% of the total thickness of the crosslinked modified anti-tritium permeation composite material.

3. The crosslinking modified, tritium impermeable composite of claim 1, wherein, The melt index of the TPEE elastomer is 5-10 g / 10min; The melt index of the high-density polyethylene resin is 2-5 g / 10min; The melt index of the maleic anhydride grafted polyethylene resin is 2-10 g / 10min; The antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate, dilauryl thiodipropionate and tris(2,4-di-tert-butyl) phenyl phosphite; The rare earth oxide is selected from one or more of cerium oxide, gadolinium oxide and erbium oxide; The sensitizer is selected from one or more of triallyl isocyanurate, trimethylolpropane trimethacrylate and diphenylmethane bismaleimide.

4. The crosslinked modified, tritium-permeation-resistant composite material according to any one of claims 1 to 3, characterized in that The protective layer comprises the following components by weight: TPEE elastomer: 30 parts; High-density polyethylene resin: 40 parts; Maleic anhydride grafted polyethylene resin: 5 parts; EVA resin: 20 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate: 1 part; Cerium oxide: 2 parts; Triallyl isocyanurate: 2 parts; The barrier layer is selected from a PVDC resin with a methyl acrylate content of 10wt%; The heat-sealing layer is selected from an EVA resin with a vinyl acetate content of 20wt%.

5. The crosslinked modified, tritium-permeation-resistant composite material according to any one of claims 1 to 3, characterized in that The protective layer comprises the following components by weight: TPEE elastomer: 40 parts; High-density polyethylene resin: 30 parts; Maleic anhydride grafted polyethylene resin: 4 parts; EVA resin: 15 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate: 0.75 parts; Cerium oxide: 1.5 parts; Triallyl isocyanurate: 1.5 parts; The barrier layer is selected from a PVDC resin with a methyl acrylate content of 10wt%; The heat-sealing layer is selected from an EVA resin with a vinyl acetate content of 20wt%.

6. The crosslinked modified, tritium-permeation-resistant composite material according to any one of claims 1 to 3, characterized in that The protective layer comprises the following components by weight: TPEE elastomer: 50 parts; High density polyethylene resin: 20 parts; Maleic anhydride grafted polyethylene resin: 3 parts; EVA resin: 10 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 0.5 parts; Cerium oxide: 1 part; Triallyl isocyanurate: 1 part; The barrier layer is selected from PVDC resin with 10wt% of methyl acrylate content; The heat-seal layer is selected from EVA resin with 20wt% of vinyl acetate content.

7. The crosslinked modified, tritium-permeation-resistant composite material according to any one of claims 1 to 3, characterized in that The protective layer comprises the following ingredients by weight parts: TPEE elastomer: 30 parts; High density polyethylene resin: 40 parts; Maleic anhydride grafted polyethylene resin: 5 parts; EVA resin: 20 parts; Dilauryl thiodipropionate: 1 part; Gadolinium oxide: 2 parts; Trimethylolpropane trimethacrylate: 2 parts; The barrier layer is selected from PVDC resin with 10wt% of methyl acrylate content; The heat-seal layer is selected from EVA resin with 20wt% of vinyl acetate content.

8. A method of producing the crosslinked modified anti-tritium permeation composite material according to any one of claims 1 to 7, characterized by, The steps include: 1) mixing TPEE elastomer, high density polyethylene, maleic anhydride grafted polyethylene, EVA resin, antioxidant, rare earth oxide and sensitizer, extruding and granulating to obtain modified resin; 2) extruding the modified resin obtained above, PVDC resin film with 5wt%-10wt% of methyl acrylate content and EVA resin film with 10wt%-20wt% of vinyl acetate content respectively to obtain modified resin film, PVDC resin film and EVA resin film, then laminating them in turn, and then preparing cross-linked modified anti-tritium permeation composite material by irradiation cross-linking.

9. The production method according to claim 8, characterized by, The temperature of extrusion in step 1) is 180°C-220°C; The screw rotation speed of extrusion is 50-70 rpm / min; The dose of irradiation treatment in step 2) is 30-50 kGy.

10. A tritium permeation resistant apparatus, characterized by, The cross-linked modified anti-tritium permeation composite material prepared by the preparation method of any one of claims 1-7 or 8-9. The cross-linked modified anti-tritium permeation composite material prepared by the preparation method of any one of claims 1-7 or 8-9.

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