A dual barrier layer tritium permeation resistant composite and method of making same

Abstract

The application discloses a kind of double barrier layer anti-tritium permeation composite material and preparation method thereof, belong to anti-tritium permeation composite material technical field.The double barrier layer anti-tritium permeation composite material includes protective layer / barrier layer 1 / barrier layer 2 / heat-seal layer in turn from outside to inside.The protective layer includes: low-density polyethylene resin, high-density polyethylene resin, maleic anhydride grafted polyethylene resin, antioxidant, heavy metal oxide, metal oxide.The barrier layer 1 is selected from EVOH resin with ethylene content of 25wt%-45wt%, the barrier layer 2 is selected from PVDC resin with methyl acrylate content of 5wt%-10wt%, and the heat-seal layer is selected from EVA resin with vinyl acetate content of 10wt%-20wt%.The double barrier layer anti-tritium permeation composite material has excellent low-temperature heat-sealability, anti-tritium permeability and interlayer bonding performance, and can resist low-energy beta radiation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anti-tritium permeation composite material, in particular to a double-barrier-layer anti-tritium permeation composite material and a preparation method thereof. BACKGROUND

[0002] Tritium is a low-energy emitter with high specific activity, which is a low-toxicity and difficult-to-protect radioactive nuclide. The main radiation hazards of tritium come from the internal irradiation hazards caused by direct inhalation and skin absorption. In the aspect of personal safety protection of tritium, tritium glove box and tritium protective clothing are the main protective equipment, which can reduce the penetration and harm of tritium to human body to a certain extent, and have an irreplaceable role in tritium technology and tritium protection.

[0003] When selecting tritium protective clothing, the permeability of the material is mainly considered. The tritium protective clothing is made of high molecular materials such as vulcanized rubber, cellophane, polyvinyl chloride and polyethylene. Since the tritium has a large permeability in the above materials, it cannot meet the performance requirements of tritium protective clothing. At present, it is urgent to develop a new type of anti-tritium permeation composite material to meet the performance requirements of high-performance anti-tritium clothing, which has important practical significance for the application of tritium protective clothing. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to provide a double-barrier-layer anti-tritium permeation composite material and a preparation method thereof. The double-barrier-layer anti-tritium permeation composite material has the advantages of good heat sealing, low tritium permeability and good chemical permeability resistance.

[0005] To achieve the above purposes, the technical scheme adopted by the present application is as follows:

[0006] The present application provides a double-barrier-layer anti-tritium permeation composite material, which comprises, from outside to inside, a protective layer, a barrier layer 1, a barrier layer 2 and a heat sealing layer.

[0007] The protective layer comprises the following components by weight:

[0008] Low-density polyethylene resin: 30-50 parts;

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

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

[0011] Antioxidant: 0.5-1 part;

[0012] Heavy metal oxide: 3-5 parts;

[0013] Metal oxide: 2-4 parts;

[0014] The barrier layer 1 is selected from EVOH resin with an ethylene content of 25wt%-45wt%.

[0015] The barrier layer 2 is selected from a PVDC resin with a methyl acrylate (MA) content of 5wt%-10wt%;

[0016] The heat-seal layer is selected from an EVA resin with a vinyl acetate (VA) content of 10wt%-20wt%.

[0017] The present application simultaneously introduces heavy metal oxides and metal oxides in the protective layer, and the two have a synergistic effect, so that the double-barrier layer tritium permeation-resistant composite material has excellent resistance to low-energy β irradiation.

[0018] In the above protective layer, the high-density polyethylene has a higher melting point and better heat resistance and mechanical strength, while the low-density polyethylene has better processability and flexibility, and the two can be modified complementarily.

[0019] The other components in the protective layer interact to improve the low-temperature heat-sealability, tritium permeation resistance, and interlayer bonding performance of the double-barrier layer tritium permeation-resistant composite material.

[0020] In addition, the double-barrier layer can better reduce the tritium permeation rate. Preferably, the total thickness of the double-barrier layer tritium permeation-resistant composite material is 0.15-0.2mm; more preferably, 0.15mm or 0.2mm.

[0021] Preferably, the thickness of the protective layer is 35%-40% of the total thickness of the double-barrier layer tritium permeation-resistant composite material; more preferably, 35% or 40%.

[0022] Preferably, the thickness of the barrier layer 1 is 10%-15% of the total thickness of the double-barrier layer tritium permeation-resistant composite material; more preferably, 10% or 15%. Preferably, the thickness of the barrier layer 2 is 10%-15% of the total thickness of the double-barrier layer tritium permeation-resistant composite material; more preferably, 10% or 15%. Preferably, the thickness of the heat-seal layer is 35%-40% of the total thickness of the double-barrier layer tritium permeation-resistant composite material; more preferably, 35% or 40%.

[0023] In some specific embodiments of the present application, the total thickness of the protective layer / barrier layer 1 / barrier layer 2 / heat-seal layer is 0.2mm, and the thicknesses of the protective layer, barrier layer 1, barrier layer 2, and heat-seal layer are 0.07mm, 0.03mm, 0.03mm, and 0.07mm, respectively.

[0024] In some embodiments of the present application, the total thickness of the protective layer / barrier layer 1 / barrier layer 2 / heat-seal layer is 0.15 mm, and the thicknesses of the protective layer, barrier layer 1, barrier layer 2, and heat-seal layer are 0.06 mm, 0.015 mm, 0.015 mm, and 0.06 mm, respectively. Preferably, the low-density polyethylene resin has a melt index of 1-3 g / 10 min.

[0025] Preferably, the high-density polyethylene resin has a melt index of 2-5 g / 10 min.

[0026] Preferably, the maleic anhydride grafted polyethylene resin has a melt index of 2-10 g / 10 min.

[0027] Preferably, the antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, dilauryl thiodipropionate, and tris(2,4-di-tert-butyl)phenyl phosphite.

[0028] Preferably, the heavy metal oxide is selected from one or more of tungsten oxide, tantalum oxide, and lead oxide.

[0029] Preferably, the metal oxide is selected from one or more of bismuth oxide, gadolinium oxide, and erbium oxide.

[0030] More preferably, the protective layer comprises, by weight parts, the following components:

[0031] Low-density polyethylene resin: 30 parts;

[0032] High-density polyethylene resin: 40 parts;

[0033] Maleic anhydride grafted polyethylene resin: 5 parts;

[0034] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester: 1 part;

[0035] Tungsten oxide: 5 parts;

[0036] Bismuth oxide: 2 parts;

[0037] The barrier layer 1 is selected from an EVOH resin having an ethylene content of 45 wt%.

[0038] The barrier layer 2 is selected from a PVDC resin having a methyl acrylate content of 10 wt%.

[0039] The heat-seal layer is selected from an EVA resin having a vinyl acetate content of 20 wt%.

[0040] Further preferably, the protective layer comprises, by weight parts, the following components:

[0041] Low density polyethylene resin with a melt index of 1 g / 10 min: 30 parts;

[0042] High density polyethylene resin with a melt index of 2 g / 10 min: 40 parts;

[0043] Maleic anhydride grafted polyethylene resin with a melt index of 2 g / 10 min: 5 parts;

[0044] β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 1 part;

[0045] Tungsten oxide: 5 parts;

[0046] Bismuth oxide: 2 parts;

[0047] Said barrier layer 1 is selected from EVOH resin with an ethylene content of 45 wt%;

[0048] Said barrier layer 2 is selected from PVDC resin with a methyl acrylate content of 10 wt%;

[0049] Said heat-seal layer is selected from EVA resin with a vinyl acetate content of 20 wt%. More preferably, said protective layer, by parts by weight, comprises the following ingredients:

[0050] Low density polyethylene resin with a melt index of 1 g / 10 min: 40 parts;

[0051] High density polyethylene resin with a melt index of 2 g / 10 min: 30 parts;

[0052] Maleic anhydride grafted polyethylene resin: 4 parts;

[0053] β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 0.75 parts;

[0054] Tungsten oxide: 4 parts;

[0055] Bismuth oxide: 3 parts;

[0056] Said barrier layer 1 is selected from EVOH resin with an ethylene content of 45 wt%;

[0057] Said barrier layer 2 is selected from PVDC resin with a methyl acrylate content of 10 wt%;

[0058] Said heat-seal layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0059] More preferably, said protective layer, by parts by weight, comprises the following ingredients: Low density polyethylene resin with a melt index of 1 g / 10 min: 40 parts;

[0060] High density polyethylene resin with a melt index of 2 g / 10 min: 30 parts;

[0061] Maleic anhydride grafted polyethylene resin with a melt index of 2 g / 10 min: 4 parts;

[0062] β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 0.75 parts;

[0063] Tungsten oxide: 4 parts;

[0064] Bismuth oxide: 3 parts;

[0065] Said barrier layer 1 is selected from EVOH resin with an ethylene content of 45 wt%;

[0066] Said barrier layer 2 is selected from PVDC resin with a methyl acrylate content of 10 wt%;

[0067] Said heat-seal layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0068] More preferably, said protective layer comprises, by weight parts:

[0069] High density polyethylene resin: 20 parts;

[0070] Maleic anhydride grafted polyethylene resin with a melt index of 2 g / 10 min: 2 parts;

[0071] β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 0.5 parts;

[0072] Tungsten oxide: 3 parts;

[0073] Bismuth oxide: 4 parts;

[0074] Said barrier layer 1 is selected from EVOH resin with an ethylene content of 45 wt%;

[0075] Said barrier layer 2 is selected from PVDC resin with a methyl acrylate content of 10 wt%;

[0076] Said heat-seal layer is selected from EVA resin with a vinyl acetate content of 20 wt%.

[0077] Further preferably, said protective layer comprises, by weight parts:

[0078] Low density polyethylene resin with a melt index of 1 g / 10 min: 50 parts;

[0079] High density polyethylene resin with a melt index of 2 g / 10 min: 20 parts;

[0080] Maleic anhydride grafted polyethylene resin with a melt index of 2 g / 10 min: 2 parts;

[0081] β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester: 0.5 parts;

[0082] Tungsten oxide: 3 parts;

[0083] Bismuth oxide: 4 parts;

[0084] Said barrier layer 1 is selected from EVOH resins with an ethylene content of 45 wt%;

[0085] Said barrier layer 2 is selected from PVDC resins with a methyl acrylate content of 10 wt%;

[0086] Said heat-seal layer is selected from EVA resins with a vinyl acetate content of 20 wt%.

[0087] More preferably, said protective layer comprises, by weight parts:

[0088] Low-density polyethylene resin: 30 parts;

[0089] High-density polyethylene resin: 40 parts;

[0090] Maleic anhydride grafted polyethylene resin: 5 parts;

[0091] Dilauryl thiodipropionate: 1 part;

[0092] Tantalum oxide: 5 parts;

[0093] Gadolinium oxide: 2 parts;

[0094] Said barrier layer 1 is selected from EVOH resins with an ethylene content of 25 wt%;

[0095] Said barrier layer 2 is selected from PVDC resins with a methyl acrylate content of 5 wt%;

[0096] Said heat-seal layer is selected from EVA resins with a vinyl acetate content of 10 wt%.

[0097] Further preferably, said protective layer comprises, by weight parts:

[0098] Low-density polyethylene resin with a melt index of 3 g / 10 min: 30 parts;

[0099] High-density polyethylene resin with a melt index of 5 g / 10 min: 40 parts;

[0100] Maleic anhydride grafted polyethylene resin with a melt index of 10 g / 10 min: 5 parts;

[0101] Dilauryl thiodipropionate: 1 part;

[0102] Tantalum oxide: 5 parts;

[0103] Gadolinium oxide: 2 parts;

[0104] Said barrier layer 1 is selected from EVOH resins with ethylene content of 25 wt%;

[0105] Said barrier layer 2 is selected from PVDC resins with methyl acrylate content of 5 wt%;

[0106] Said heat-seal layer is selected from EVA resins with vinyl acetate content of 10 wt%. More preferably, according to the present application, said protective layer comprises, by weight parts:

[0107] Low density polyethylene resin with melt index of 3 g / 10 min: 30 parts;

[0108] High density polyethylene resin with melt index of 5 g / 10 min: 40 parts;

[0109] Maleic anhydride grafted polyethylene resin with melt index of 10 g / 10 min: 5 parts;

[0110] Tris(2,4-di-tert-butyl) phosphite: 1 part;

[0111] Lead oxide: 5 parts;

[0112] Erbium oxide: 2 parts;

[0113] Said barrier layer 1 is selected from EVOH resins with ethylene content of 25 wt%;

[0114] Said barrier layer 2 is selected from PVDC resins with methyl acrylate content of 5 wt%;

[0115] Said heat-seal layer is selected from EVA resins with vinyl acetate content of 10 wt%.

[0116] More preferably, according to the present application, said protective layer comprises, by weight parts:

[0117] Low density polyethylene resin with melt index of 3 g / 10 min: 30 parts;

[0118] High density polyethylene resin with melt index of 5 g / 10 min: 40 parts;

[0119] Maleic anhydride grafted polyethylene resin with melt index of 10 g / 10 min: 5 parts;

[0120] Tris(2,4-di-tert-butyl) phosphite: 1 part;

[0121] Lead oxide: 5 parts;

[0122] Erbium oxide: 2 parts;

[0123] Said barrier layer 1 is selected from EVOH resins with ethylene content of 25 wt%;

[0124] The barrier layer 2 is selected from a PVDC resin with a methyl acrylate content of 5wt%;

[0125] The heat-sealing layer is selected from an EVA resin with a vinyl acetate content of 10wt%. The present application also provides a preparation method of a double-barrier-layer tritium-permeation-resistant composite material, comprising the following steps:

[0126] 1) mixing low-density polyethylene, high-density polyethylene, maleic anhydride grafted polyethylene, an antioxidant, a heavy metal oxide, and a metal oxide, and then extruding and granulating to obtain a modified resin for a protective layer;

[0127] 2) extruding the modified resin for a protective layer obtained in step 1), an EVOH resin with an ethylene content of 25%-45%, a PVDC resin with a methyl acrylate content of 5-10%, and an EVA resin with a vinyl acetate content of 10wt%-20wt% to obtain a modified resin film for a protective layer, an EVOH resin film, a PVDC resin film, and an EVA resin film, respectively, and then sequentially laminating from the outside to the inside, and then performing cooling, drawing, and winding to obtain a double-barrier-layer tritium-permeation-resistant composite material.

[0128] The double-barrier-layer tritium-permeation-resistant composite material is prepared by the above preparation method.

[0129] Preferably, in step 1), the extrusion temperature is 180-220℃. In some specific embodiments of the present application, the extrusion temperature is preferably 180℃ or 220℃.

[0130] Preferably, in step 1), the screw rotation speed during extrusion is 50-70rpm / min.

[0131] In the above preparation method, in step 2), the extrusion temperature of the modified resin film for a protective layer is preferably 180-220℃, and the screw rotation speed is preferably 25-35r / min.

[0132] In some specific embodiments of the present application, the extrusion temperature of the modified resin film for a protective layer is 180℃, and the screw rotation speed is preferably 35r / min.

[0133] In some specific embodiments of the present application, the extrusion temperature of the modified resin film for a protective layer is 220℃, and the screw rotation speed is preferably 25r / min.

[0134] In the above preparation method, in step 2), the extrusion temperature of the EVOH resin film is preferably 190-220℃, and the screw rotation speed is preferably 10-15r / min.

[0135] In some specific embodiments of the present application, the extrusion temperature of the EVOH resin film is 220℃, and the screw rotation speed is preferably 15r / min.

[0136] In some embodiments of the present application, the extrusion temperature of the EVOH resin film is 190°C, and the screw rotation speed is preferably 10 r / min.

[0137] The extrusion temperature of the PVDC resin film in the step 2) is preferably 170-190°C, and the screw rotation speed is preferably 10-15 r / min.

[0138] In some embodiments of the present application, the extrusion temperature of the PVDC resin film is 190°C, and the screw rotation speed is preferably 15 r / min.

[0139] In some embodiments of the present application, the extrusion temperature of the PVDC resin film is 170°C, and the screw rotation speed is preferably 10 r / min.

[0140] The extrusion temperature of the EVA resin film in the step 2) is preferably 180-220°C, and the screw rotation speed is preferably 25-35 r / min.

[0141] In some embodiments of the present application, the extrusion temperature of the EVA resin film is 180°C, and the screw rotation speed is preferably 35 r / min.

[0142] In some embodiments of the present application, the extrusion temperature of the EVA resin film is 220°C, and the screw rotation speed is preferably 25 r / min.

[0143] The present application also provides a tritium permeation prevention equipment comprising the double-barrier-layer tritium permeation prevention composite material or the double-barrier-layer tritium permeation prevention composite material prepared by the preparation method.

[0144] The tritium permeation prevention equipment includes but is not limited to protective clothing, protective gloves, etc.

[0145] Compared with the prior art, the double-barrier layer anti-tritium permeation composite material provided by the application comprises, from outside to inside, a protective layer, a barrier layer 1, a barrier layer 2 and a heat-sealing layer. The protective layer comprises, by weight, the following components: 30-50 parts of low-density polyethylene resin, 20-40 parts of high-density polyethylene resin, 3-5 parts of maleic anhydride grafted polyethylene resin, 0.5-1 part of antioxidant, 3-5 parts of heavy metal oxide and 2-4 parts of metal oxide. The barrier layer 1 is selected from EVOH resin with an ethylene content of 25wt%-45wt%, the barrier layer 2 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 double-barrier layer anti-tritium permeation composite material has excellent low-temperature heat-sealing property, anti-tritium permeation property and interlayer bonding property, and has the ability to resist low-energy beta irradiation. In the preparation of tritium protection equipment, the double-barrier layer anti-tritium permeation composite material has a wide application prospect. DETAILED DESCRIPTION

[0146] In order to further illustrate the application, the double-barrier layer anti-tritium permeation composite material and the preparation method thereof provided by the application are described in detail below in combination with examples.

[0147] Example 1

[0148] (1) Preparation of modified resin for protective layer

[0149] 30 parts of low-density polyethylene with a melt index of 1g / 10min, 40 parts of high-density polyethylene with a melt index of 2g / 10min, 5 parts of maleic anhydride grafted polyethylene with a melt index of 2g / 10min, 1 part of β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate, 5 parts of tungsten oxide and 2 parts of bismuth oxide.

[0150] The raw materials are weighed according to the above proportions, poured into a mixer, the stirring speed is controlled at 400rpm / min, the dispersion speed is controlled at 800rpm / min, and the stirring time is controlled at 10min. After mixing uniformly, the above raw materials are added to a double-screw extruder, the temperature is controlled at 220℃, and the screw speed is controlled at 70rpm / min. Mixing and granulation are carried out to obtain the modified resin for the protective layer.

[0151] (2) Preparation of double-barrier layer anti-tritium permeation composite material

[0152] The modified resin for the protective layer, EVOH resin with an ethylene content of 45%, PVDC resin with a MA (methyl acrylate) content of 10%, and EVA resin with a VA content of 20% were respectively added to four single-screw extruders A, B, C, and D of a co-extrusion device. The temperature of the body of the single-screw extruder A was 220°C, and the screw rotation speed was 25 r / min; the temperature of the body of the single-screw extruder B was 220°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder C was 190°C, and the screw rotation speed was 15 r / min; and the temperature of the body of the single-screw extruder D was 220°C, and the screw rotation speed was 25 r / min. The polymer melts were respectively extruded into the die by the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding treatment to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 35% / 15% / 15% / 35%) with a thickness of 0.2 mm.

[0153] Example 2

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

[0155] Low-density polyethylene with a melt index of 1 g / 10 min 40 parts, high-density polyethylene with a melt index of 2 g / 10 min 30 parts, maleic anhydride grafted polyethylene with a melt index of 2 g / 10 min 4 parts, β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate 0.75 parts, tungsten oxide 4 parts, and bismuth oxide 3 parts.

[0156] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 400 rpm / min, the dispersion speed was controlled at 800 rpm / min, and the stirring time was controlled at 10 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 220°C, and the screw rotation speed was controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0157] (2) Preparation of the double-barrier layer anti-tritium permeation composite material

[0158] The modified resin for the protective layer, EVOH resin with an ethylene content of 45%, PVDC resin with a MA (methyl acrylate) content of 10%, and EVA resin with a VA content of 20% were respectively added to four single-screw extruders A, B, C, and D of a co-extrusion device. The temperature of the body of the single-screw extruder A was 220°C, and the screw rotation speed was 25 r / min; the temperature of the body of the single-screw extruder B was 220°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder C was 190°C, and the screw rotation speed was 15 r / min; and the temperature of the body of the single-screw extruder D was 220°C, and the screw rotation speed was 25 r / min. The polymer melts were respectively extruded into the die by the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding treatment to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 35% / 15% / 15% / 35%) with a thickness of 0.2 mm.

[0159] Example 3

[0160] (1) Preparation of the modified resin for the protective layer

[0161] Low-density polyethylene with a melt index of 1 g / 10 min 50 parts, high-density polyethylene with a melt index of 2 g / 10 min 20 parts, maleic anhydride grafted polyethylene with a melt index of 2 g / 10 min 2 parts, β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate 0.5 parts, tungsten oxide 3 parts, and bismuth oxide 4 parts.

[0162] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 400 rpm / min, the dispersion speed was controlled at 800 rpm / min, and the stirring time was controlled at 10 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 220°C, and the screw rotation speed was controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0163] (2) Preparation of the anti-tritium permeation composite material with double barrier layers

[0164] The modified resin for the protective layer, EVOH resin with an ethylene content of 45%, PVDC resin with a MA (methyl acrylate) content of 10%, and EVA resin with a VA content of 20% were respectively added to four single-screw extruders A, B, C, and D of a co-extrusion device. The temperature of the body of the single-screw extruder A was 220°C, and the screw rotation speed was 25 r / min; the temperature of the body of the single-screw extruder B was 220°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder C was 190°C, and the screw rotation speed was 15 r / min; and the temperature of the body of the single-screw extruder D was 220°C, and the screw rotation speed was 25 r / min. The polymer melts were respectively extruded into the die by the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding treatment to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 35% / 15% / 15% / 35%) with a thickness of 0.2 mm.

[0165] Example 4

[0166] (1) Preparation of the modified resin for the protective layer

[0167] Low-density polyethylene with a melt index of 3 g / 10 min 30 parts, high-density polyethylene with a melt index of 5 g / 10 min 40 parts, maleic anhydride grafted polyethylene with a melt index of 10 g / 10 min 5 parts, dilauryl thiodipropionate 1 part, tantalum oxide 5 parts, and gadolinium oxide 2 parts.

[0168] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 200 rpm / min, the dispersion speed was controlled at 500 rpm / min, and the stirring time was controlled at 5 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 180°C, and the screw rotation speed was controlled at 50 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0169] (2) Preparation of the anti-tritium permeation composite material with double barrier layers

[0170] The modified resin for the protective layer, EVOH resin with an ethylene content of 25%, PVDC resin with a MA (methyl acrylate) content of 5%, and EVA resin with a VA content of 10% were respectively added to four single-screw extruders A, B, C, and D of a co-extrusion device. The temperature of the body of the single-screw extruder A was 180°C, and the screw rotation speed was 35 r / min; the temperature of the body of the single-screw extruder B was 190°C, and the screw rotation speed was 10 r / min; the temperature of the body of the single-screw extruder C was 170°C, and the screw rotation speed was 10 r / min; and the temperature of the body of the single-screw extruder D was 180°C, and the screw rotation speed was 35 r / min. The polymer melts were respectively extruded into the die by the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 40% / 10% / 10% / 40%) with a thickness of 0.15 mm.

[0171] Example 5

[0172] (1) Preparation of the modified resin for the protective layer

[0173] Low-density polyethylene with a melt index of 3 g / 10 min 30 parts, high-density polyethylene with a melt index of 5 g / 10 min 40 parts, maleic anhydride grafted polyethylene with a melt index of 10 g / 10 min 5 parts, tris (2, 4-di-tert-butyl) phenyl phosphite 1 part, lead oxide 5 parts, and erbium oxide 2 parts.

[0174] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 200 rpm / min, the dispersion speed was controlled at 500 rpm / min, and the stirring time was controlled at 5 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 180°C, and the screw rotation speed was controlled at 50 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0175] (2) Preparation of the anti-tritium permeation composite material with double barrier layers

[0176] The modified resin for the protective layer, EVOH resin with an ethylene content of 25%, PVDC resin with a MA (methyl acrylate) content of 5%, and EVA resin with a VA content of 10% were respectively added to four single-screw extruders A, B, C, and D of a co-extrusion device. The temperature of the body of the single-screw extruder A was 180°C, and the screw rotation speed was 35 r / min; the temperature of the body of the single-screw extruder B was 190°C, and the screw rotation speed was 10 r / min; the temperature of the body of the single-screw extruder C was 170°C, and the screw rotation speed was 10 r / min; and the temperature of the body of the single-screw extruder D was 180°C, and the screw rotation speed was 35 r / min. The polymer melts were respectively extruded into the die by the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 40% / 10% / 10% / 40%) with a thickness of 0.15 mm.

[0177] Comparative Example 1

[0178] (1) Preparation of the modified resin for the protective layer

[0179] 30 parts of low-density polyethylene with a melt index of 1 g / 10 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, 1 part of β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate, 5 parts of tungsten oxide, and 2 parts of bismuth oxide.

[0180] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 400 rpm / min, the dispersion speed was controlled at 800 rpm / min, and the stirring time was controlled at 10 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 220°C, and the screw rotation speed was controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0181] (2) Preparation of Comparative Sample 1

[0182] The modified resin for the protective layer, EVOH resin with ethylene content of 45%, and EVA resin with VA content of 20% were added into four single-screw extruders A, B, C, and D of a co-extrusion device, respectively. The temperature of the body of the single-screw extruder A was 220°C, and the screw rotation speed was 25 r / min; the temperature of the body of the single-screw extruder B was 220°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder C was 220°C, and the screw rotation speed was 15 r / min; and the temperature of the body of the single-screw extruder D was 220°C, and the screw rotation speed was 25 r / min. The polymer melts were extruded into the die from the corresponding extruders for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing, and winding to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 35% / 15% / 15% / 35%) with a thickness of 0.2 mm.

[0183] Comparative Example 2

[0184] (1) Preparation of the modified resin for the protective layer

[0185] Low-density polyethylene with a melt index of 1 g / 10 min 30 parts, high-density polyethylene with a melt index of 2 g / 10 min 40 parts, maleic anhydride grafted polyethylene with a melt index of 2 g / 10 min 5 parts, β-(3,5-di-tert-butyl-4-hydroxyphenyl) octadecyl propionate 1 part, tungsten oxide 5 parts, and bismuth oxide 2 parts.

[0186] The raw materials were weighed according to the above proportions, poured into a mixer, the stirring speed was controlled at 400 rpm / min, the dispersion speed was controlled at 800 rpm / min, and the stirring time was controlled at 10 min. After mixing uniformly, the above raw materials were added to a twin-screw extruder, the temperature was controlled at 220°C, and the screw rotation speed was controlled at 70 rpm / min for mixing and granulation to obtain the modified resin for the protective layer.

[0187] (2) Preparation of Comparative Sample 2

[0188] The modified resin for the protective layer, the PVDC resin with 10% of MA (methyl acrylate) content and the EVA resin with 20% of VA content were respectively added into four single-screw extruders A, B, C and D of the co-extrusion device. The temperature of the body of the single-screw extruder A was 220°C, and the screw rotation speed was 25 r / min; the temperature of the body of the single-screw extruder B was 190°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder C was 190°C, and the screw rotation speed was 15 r / min; the temperature of the body of the single-screw extruder D was 220°C, and the screw rotation speed was 25 r / min. The polymer melt was respectively extruded into the die by the corresponding extruder for lamination to obtain a film blank, and the film blank was subjected to cooling, drawing and winding treatment to obtain a multi-layer structure anti-tritium permeation composite material (thickness ratio 35% / 15% / 15% / 35%) with a thickness of 0.2 mm.

[0189] Comparative Example 3

[0190] The same as Example 1, except that the EVOH resin (barrier layer 1) with an ethylene content of 45% was replaced by an HDPE resin.

[0191] Comparative Example 4

[0192] The same as Example 2, except that no heavy metal oxide (tungsten oxide) and metal oxide (bismuth oxide) were added in the protective layer.

[0193] The properties of the double-barrier anti-tritium permeation composite materials prepared in the above Examples 1-5 and Comparative Examples 1-4 were tested, and the test results are shown in Table 1.

[0194] Table 1. Test results of the properties of the double-barrier anti-tritium permeation composite materials

[0195]

[0196] The above examples are only used to help understand the method of the present application and its core idea. It should be noted that for those skilled in the art, without departing from the principles of the present application, the present application can be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A dual barrier layer tritium permeation resistant composite material, characterized by, The protective layer / barrier layer 1 / barrier layer 2 / heat-sealing layer are sequentially arranged from outside to inside; The protective layer comprises the following components by weight: Low-density polyethylene resin: 30-50 parts; High-density polyethylene resin: 20-40 parts; Maleic anhydride grafted polyethylene resin: 3-5 parts; Antioxidant: 0.5-1 part; Heavy metal oxide: 3-5 parts; Metal oxide: 2-4 parts; The barrier layer 1 is selected from EVOH resin with ethylene content of 25wt%-45wt%; The barrier layer 2 is selected from PVDC resin with methyl acrylate content of 5wt%-10wt%; The heat-sealing layer is selected from EVA resin with vinyl acetate content of 10wt%-20wt%; The heavy metal oxide is selected from one or more of tungsten oxide, tantalum oxide, and lead oxide; The metal oxide is selected from one or more of bismuth oxide, gadolinium oxide, and erbium oxide.

2. The dual barrier layer tritium permeation resistant composite of claim 1, wherein, The total thickness of the double-barrier-layer 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 double-barrier-layer anti-tritium-permeation composite material; The thickness of the barrier layer 1 is 10%-15% of the total thickness of the double-barrier-layer anti-tritium-permeation composite material; The thickness of the barrier layer 2 is 10%-15% of the total thickness of the double-barrier-layer anti-tritium-permeation composite material; The thickness of the heat-sealing layer is 35%-40% of the total thickness of the double-barrier-layer anti-tritium-permeation composite material.

3. The dual barrier layer tritium permeation resistant composite of claim 1, wherein, The low-density polyethylene resin has a melt index of 1-3 g / 10min; The high-density polyethylene resin has a melt index of 2-5 g / 10min; The maleic anhydride grafted polyethylene resin has a melt index of 2-10 g / 10min.

4. The dual barrier layer tritium permeation resistant composite of claim 1, wherein, The antioxidant is selected from one or more of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, dilauryl thiodipropionate, and tris(2,4-di-tert-butyl)phenyl phosphite.

5. The biliayer tritium permeation barrier composite of any of claims 1-4, wherein, The protective layer comprises the following components by weight: Low-density polyethylene resin: 30 parts; High-density polyethylene resin: 40 parts; Maleic anhydride grafted polyethylene resin: 5 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester: 1 part; Tungsten oxide: 5 parts; Bismuth oxide: 2 parts; The barrier layer 1 is selected from EVOH resin with ethylene content of 45wt%; The barrier layer 2 is selected from PVDC resin with methyl acrylate content of 10wt%; The heat-sealing layer is selected from EVA resin with vinyl acetate content of 20wt%.

6. The dual barrier layer tritium permeation resistant composite of any of claims 1-4, wherein, The protective layer comprises the following components by weight: Low-density polyethylene resin: 40 parts; High-density polyethylene resin: 30 parts; Maleic anhydride grafted polyethylene resin: 4 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester: 0.75 parts; Tungsten oxide: 4 parts; Bismuth oxide: 3 parts; The barrier layer 1 is selected from EVOH resin with ethylene content of 45wt%; The barrier layer 2 is selected from PVDC resin with methyl acrylate content of 10wt%; The heat-sealing layer is selected from EVA resin with vinyl acetate content of 20wt%.

7. A dual barrier layer tritium permeation resistant composite material, characterized by, from outside to inside, it includes protective layer / barrier layer 1 / barrier layer 2 / heat-sealing layer in turn; The protective layer comprises the following ingredients by weight: Low-density polyethylene resin: 50 parts; High-density polyethylene resin: 20 parts; Maleic anhydride grafted polyethylene resin: 2 parts; β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid octadecyl ester: 0.5 parts; Tungsten oxide: 3 parts; Bismuth oxide: 4 parts; The barrier layer 1 is selected from EVOH resin with ethylene content of 45wt%; The barrier layer 2 is selected from PVDC resin with methyl acrylate content of 10wt%; The heat-sealing layer is selected from EVA resin with vinyl acetate content of 20wt%.

8. The biliayer tritium permeation barrier composite of any of claims 1-4, wherein, The protective layer comprises the following ingredients by weight: Low-density polyethylene resin: 30 parts; High-density polyethylene resin: 40 parts; Maleic anhydride grafted polyethylene resin: 5 parts; Dilauryl thiodipropionate: 1 part; Tantalum oxide: 5 parts; Gadolinium oxide: 2 parts; The barrier layer 1 is selected from EVOH resin with ethylene content of 25wt%; The barrier layer 2 is selected from PVDC resin with methyl acrylate content of 5wt%; The heat-sealing layer is selected from EVA resin with vinyl acetate content of 10wt%.

9. A method of making a biliayer tritium permeation barrier composite material according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: 1) mixing low-density polyethylene, high-density polyethylene, maleic anhydride grafted polyethylene, antioxidant, heavy metal oxide and metal oxide, extruding and granulating to obtain modified resin for protective layer; 2) extruding the modified resin for protective layer, EVOH resin with ethylene content of 25%-45%, PVDC resin with methyl acrylate content of 5-10% and EVA resin with vinyl acetate content of 10wt%-20wt% respectively to obtain modified resin film for protective layer, EVOH resin film, PVDC resin film and EVA resin film, then laminating from outside to inside in turn, and then cooling, drawing and winding to obtain double-barrier-layer anti-tritium-permeation composite material.

10. A tritium permeation resistant apparatus, characterized by, The double-barrier-layer anti-tritium-permeation composite material prepared by the method of any one of claims 1-8 or the method of claim 9. The double-barrier-layer anti-tritium-permeation composite material prepared by the method of any one of claims 1-8 or the method of claim 9.

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