Preparation method of nuclear radiation protection material

Abstract

The invention discloses a preparation method of a nuclear radiation protection material, and belongs to the technical field of nuclear radiation protection material preparation, and the process comprises the following steps: respectively plastifying natural rubber and chloroprene rubber; adding sulfur, an accelerant M, an accelerant D, zinc oxide, stearic acid, carbon black, an anti-aging agent A, bismuth powder, tungsten powder and praseodymium oxide into the plastified natural rubber, and mixing to prepare a natural rubber compound; adding magnesium oxide, stearic acid, carbon black, zinc oxide, an accelerant NA-22, an anti-aging agent D, rosin and coumarone resin into the plastified chloroprene rubber, and mixing to prepare chloroprene rubber compound; respectively cutting the natural rubber compound and the chloroprene rubber compound into particles with the particle size of less than or equal to 5cm, and dissolving the particles in an organic solvent to prepare natural rubber compound cement; coating, heating, drying and vulcanizing to obtain the nuclear radiation material. The material can shield rays under the condition of a wide energy section, and the radiation-proof effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of nuclear radiation protection materials, and more specifically to a method for preparing nuclear radiation protection materials. Background Art

[0002] Nowadays, nuclear science and technology have been widely used in the fields of aerospace, industry and agriculture, military, medical diagnosis and treatment. While bringing convenience to people's production and life, the corresponding risk of nuclear leakage is increasing. Nuclear leakage will produce radioactive substances, which will undergo radioactive linear decay and produce charged particles and rays. The most common charged particles and rays are alpha particles, beta particles, X-rays and gamma rays. External irradiation refers to irradiation from outside the body. The penetration distance of alpha particles in the air is only a few centimeters, and they cannot penetrate the surface of the skin, so alpha particles are considered to have no external irradiation hazards. β particles have stronger penetrating power than α particles, but higher energy β particles can only penetrate the skin a few millimeters, but they cause greater damage to the eyes, so except for the eyes, it can be considered that β particles do not cause external irradiation hazards. X-rays and gamma rays are both short-wavelength electromagnetic waves that can penetrate all organs in the body and can cause very serious external irradiation hazards. The energy of X-rays and gamma rays is an important factor in determining the degree of external irradiation hazards. Therefore, nuclear ray protection materials at home and abroad are mainly for the protection of X-rays and gamma rays. Common radiation sources are 241 Am, 133 8. 57 Co. 131 I etc.

[0003] Traditional X-ray and gamma-ray nuclear radiation shielding composite materials are concrete, ceramics and polymers containing lead or lead oxide. Traditional X-ray and gamma-ray nuclear radiation shielding composite materials are prone to aging and wear after long-term use. When lead powder falls off and enters the human body, it will cause blood lead poisoning in the human body. At the same time, lead itself has a high density, so traditional X-ray and gamma-ray nuclear radiation shielding composite materials have defects such as high toxicity, heavy weight, poor flexibility and difficult processing. RST Company in the United States has developed a gamma-ray shielding material containing tantalum fiber, which can achieve a protection efficiency of 50% under 130keV conditions. MI Company in Germany uses metal barium, cadmium, cesium metal particles and polyvinyl chloride substrates, combined with multi-layer overlapping technology of materials to prepare X-ray and gamma-ray protective clothing. Most of today's nuclear radiation composite materials still use rubber, epoxy resin, polyvinyl chloride (PVC), thermoplastic polyurethane (TPU) and the like as the matrix, and a single type of shielding particles as the functional component. The single type of functional component makes the nuclear radiation shielding material have a weak absorption area, and the radiation shielding effect under wide energy range conditions is not ideal.

[0004] How to provide a radiation protection material with ideal radiation protection effect is a technical problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] In view of this, the present invention is proposed.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] An embodiment of the present invention provides a method for preparing a nuclear radiation protection material, the process comprising:

[0008] S1. Plastication: plasticize the natural rubber and chloroprene rubber respectively;

[0009] S2, natural rubber mixing: adding sulfur, accelerator M, accelerator D, zinc oxide, stearic acid, carbon black, antioxidant A, bismuth powder, tungsten powder, and praseodymium oxide to the plasticized natural rubber for mixing and preparing a natural rubber compound;

[0010] S3, chloroprene rubber mixing: adding magnesium oxide, stearic acid, carbon black, zinc oxide, accelerator NA-22, antioxidant D, rosin, and coumarone resin to the plasticized chloroprene rubber for mixing to prepare a chloroprene rubber mixture;

[0011] S4. Cut the natural rubber compound and the chloroprene compound into particles with a particle size of ≤5 cm respectively, and dissolve them in an organic solvent to obtain a natural rubber compound slurry; apply, heat, dry and vulcanize to obtain a nuclear radiation material.

[0012] Preferably, in S1, the mastication is performed at 60-100°C for 10-15 min.

[0013] Preferably, in S2, the weight parts of each component are 100 parts of natural rubber, 2-3 parts of sulfur, 1-1.5 parts of accelerator M, 0-1 parts of accelerator D, 4-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 15-25 parts of carbon black, 0.5-1.5 parts of antioxidant A, 100-150 parts of bismuth powder, 40-60 parts of tungsten powder, and 20-40 parts of praseodymium oxide;

[0014] More preferably, 100 parts of natural rubber, 2.5 parts of sulfur, 1.2 parts of accelerator M, 0.4 parts of accelerator D, 5 parts of zinc oxide, 1 part of stearic acid, 20 parts of carbon black, 1 part of antioxidant A, 120 parts of bismuth powder, 50 parts of tungsten powder, and 30 parts of praseodymium oxide.

[0015] Preferably, in S3, the weight proportions of the components are 100 parts of chloroprene rubber, 3-5 parts of magnesium oxide, 0-1 parts of stearic acid, 15-25 parts of carbon black, 4-6 parts of zinc oxide, 0-1 parts of accelerator NA-22, 0.5-1.5 parts of antioxidant D, 2-3 parts of rosin, and 2-3 parts of coumarone resin;

[0016] More preferably, 100 parts of chloroprene rubber, 4 parts of magnesium oxide, 0.5 parts of stearic acid, 20 parts of carbon black, 5 parts of zinc oxide, 0.5 parts of accelerator NA-22, 1 part of antioxidant D, 2.5 parts of rosin, and 2.5 parts of coumarone resin.

[0017] Preferably, the mixing temperature and time are 40-70° C. for 30-40 min.

[0018] Preferably, in S4, the natural rubber compound is dissolved in 120# solvent oil in a weight ratio of 1:(1.5-2.5) to prepare the natural rubber compound slurry; the chloroprene rubber compound is dissolved in toluene in a weight ratio of 1:3 to prepare the chloroprene rubber compound slurry.

[0019] Preferably, in S4, the coating is to coat at least one layer of adhesive on the base fabric, and each layer is heated and dried, the heating temperature is 80-100° C., and the drying time is 10-12 min, so as to obtain a composite layer blank.

[0020] More preferably, the front side of the base fabric is coated with one layer of chloroprene rubber mixed glue and five layers of natural rubber mixed glue from the inside to the outside; the back side of the base fabric is coated with one layer of chloroprene rubber mixed glue and five layers of natural rubber mixed glue from the inside to the outside; and the coating thickness of each glue is 0.05 mm;

[0021] More preferably, the base fabric is polyester fiber.

[0022] Preferably, in S4, the vulcanization is to place the composite layer blank at a temperature of 150-170°C and a vulcanization pressure of 20-40 kg / cm 2 The sulfidation reaction is carried out in an environment for 10-15 minutes to obtain a nuclear radiation protection material;

[0023] More preferably, the vulcanization temperature is 160°C and the vulcanization pressure is 30 kg / cm 2 , lasting 12 minutes.

[0024] Preferably, in S4, before vulcanization, sodium stearate is sprayed on the front and back surfaces of the composite layer blank. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1 This example is a preferred implementation of the present invention.

[0027] A method for preparing a nuclear radiation protection material comprises the following steps:

[0028] 1. Plastication: Plasticate the natural rubber and chloroprene rubber separately to make the raw rubber change from an elastomer into a plastic material. At the same time, the plasticity of the raw rubber is uniform, which can prepare for subsequent mixing. The plastication temperature is generally 60-100℃ and the time is 10-15min.

[0029] 2. Mixing: Mix the natural rubber and chloroprene rubber according to the formula requirements, at 40-70℃, for 30-40 minutes. The purpose is to add various additives to the raw rubber, so that the various properties of the mixed rubber meet the design requirements and meet the production process conditions, which is convenient for production. For example, reinforcing agents improve strength, plasticizers improve flow and hardness, special additives improve shielding efficiency, and other additives provide a good production process, etc. The specific formula is as follows:

[0030] Table 1 Natural rubber formula

[0031] Raw material name Proportion / mass PHR Natural rubber 100 sulfur 2.5 Accelerator M 1.2 Accelerator D 0.4 Zinc Oxide 5 Stearic acid 1 Carbon Black 20 Antioxidant A 1 Bismuth powder 120 Tungsten powder 50 Praseodymium oxide 30

[0032] Table 2 Neoprene formula

[0033]

[0034]

[0035] 3. Rubber mix crushing: Cut the mixed natural rubber and chloroprene rubber into particles with a diameter of less than 5 cm. The main purpose is to facilitate dissolution and stirring and speed up the dissolution speed.

[0036] 4. Preparation of slurry: dissolve the above crushed particles in respective organic solvents, wherein:

[0037] The natural rubber compound is dissolved in 120# in a weight ratio of 1:1.5 to prepare a natural compound slurry;

[0038] The chloroprene rubber compound is dissolved in toluene in a weight ratio of 1:3 to prepare a chloroprene rubber compound slurry;

[0039] 5. Filtering: Filter out the undissolved particles and impurities in the various slurries in step 4 respectively. The main purpose of filtering is to make the obtained slurry uniform and ensure that the slurry meets the requirements of the coating (coating).

[0040] 6. Coating: The front side of the base fabric (polyester fiber with a thickness of 0.15 mm is used in this embodiment) is coated with 1 layer of chloroprene rubber mixed glue and 5 layers of natural rubber mixed glue from the inside to the outside; the back side of the base fabric is coated with 1 layer of chloroprene rubber mixed glue and 5 layers of natural rubber mixed glue from the inside to the outside.

[0041] Specific;

[0042] ①Use chloroprene rubber mixed glue to coat the front of the base fabric once, and use continuous step-by-step heating in the oven to heat and dry it. Ensure that the solvent inside the glue evaporates as much as possible.

[0043] ②Use natural rubber mixed glue to coat twice. The oven adopts continuous step-by-step heating to heat and dry. Ensure that the solvent inside the glue evaporates as much as possible.

[0044] ③ After the front side of the base fabric is coated, the back side of the base fabric is coated from the inner layer to the outer layer using the same coating process.

[0045] In this embodiment, the single coating thickness of each adhesive layer is 0.05mm, and the coating process is carried out in the coating device. After each coating, it is heated and dried in a continuous oven at a temperature of 80°C for 8 minutes. In this way, a composite layer blank is obtained. It should be pointed out that during the coating process of the coating device, the coating thickness of each coating is generally between 0.04 and 0.06mm, and the coating thickness of each coating should not exceed 0.06mm, otherwise it is easy to cause the flow and uneven thickness of the adhesive.

[0046] 7. Spray rubber isolating agent on the front and back sides of the prepared composite layer blank to prevent adhesion between rubber and rubber.

[0047] 9. Vulcanization: The composite layer blank is vulcanized using a drum vulcanizer. The rubber surface is in direct contact with the stainless steel belt and the vulcanizing roller. The vulcanized rubber tape surface feels soft and sanitary, completely getting rid of the "dirty, messy and poor" image of the rubber tape products produced by talcum powder can vulcanization. The specific process is as follows:

[0048] ① Clean the vulcanizing roller and steel belt of the vulcanizer.

[0049] ② Set the vulcanization parameters, the vulcanization time is 10-15min, the vulcanization temperature is 160℃, and the vulcanization pressure is 30kg / cm 2 . Wait for the equipment to reach the vulcanization conditions of the product.

[0050] ③ The composite layer blank is smoothly fed into the vulcanizer. The composite layer blank contacts the vulcanizing roller and the steel belt, and a fluorine release agent is used to prevent the rubber from sticking to the roller and the steel belt.

[0051] ④After vulcanization is completed, a piece of chemical-resistant tape with neat appearance, uniform texture and good tightness is obtained.

[0052] Combining the above steps, the nuclear radiation protection material of the present invention can be produced. The material has 12 rubber layers on both sides except the base fabric, with a thickness of only 0.6 mm and a weight per unit area of ​​2800 g / m2 The physical and nuclear radiation protection ratio tests of this product have shown the following:

[0053] Table 3 Comparison of the test results and standard values ​​of various physical protection indicators of the finished fabric of Example 1:

[0054]

[0055] Table 4 Comparison of protection ratio of finished material in Example 1 and standard value

[0056]

[0057] It can be seen from Table 3 that the protective clothing fabric prepared in this embodiment has good physical and mechanical properties, and also has excellent heat resistance and cold resistance.

[0058] From Table 4, it can be seen that the protection ratio of the nuclear radiation protection material to the three kinds of gamma rays is not less than 30%, which shows that the shielding efficiency of the material to gamma rays is good. In addition, the adhesion strength between the base fabric and the rubber reaches 1.1kN / m, which shows that the bonding force between the base fabric and the rubber is relatively large, and there is basically no problem of delamination between the two.

[0059] Example 2

[0060] The process of this embodiment is basically the same as that of embodiment 1, and the main difference is that in this embodiment, the ratio of the metal powder added during the mixing process of the natural rubber is slightly changed. The details are as follows:

[0061] Table 5 Natural rubber formula

[0062] Raw material name Proportion / mass PHR Natural rubber 100 sulfur 2.5 Accelerator M 1.2 Accelerator D 0.4 Zinc Oxide 5 Stearic acid 1 Carbon Black 20 Antioxidant A 1 Bismuth powder 140 Tungsten powder 60 Praseodymium oxide 20

[0063] The following results were obtained by testing the protection ratio of the nuclear radiation protection material of Example 2:

[0064] Table 6 is a comparison of the protection ratio of the finished material of Example 2 and the standard value

[0065] Average energy / keV Protection ratio Index requirements 59.5 48.9％ ≥50％ 81 47.5％ ≥40％ 122 44.7％ ≥40％

[0066] The nuclear radiation protection material prepared in this embodiment 2 is different from the nuclear radiation protection material in embodiment 1. When the average energy is 59.5keV, its protection ratio decreases and cannot meet the 50% requirement. As the proportion of tungsten powder and bismuth powder increases, the protection ratios at average energies of 81keV and 122keV are improved.

[0067] Example 3

[0068] During the mixing process of natural rubber, the ratio of metal powder added is slightly changed. The details are as follows:

[0069] Table 7 Natural rubber formula

[0070] Raw material name Proportion / mass PHR Natural rubber 100 sulfur 2.5 Accelerator M 1.2 Accelerator D 0.4 Zinc Oxide 5 Stearic acid 1 Carbon Black 20 Antioxidant A 1 Bismuth powder 125 Tungsten powder 40 Praseodymium oxide 35

[0071] The following results were obtained by testing the protection ratio of the nuclear radiation protection material of Example 2:

[0072] Table 8 is a comparison of the protection ratio of the finished material of Example 3 and the standard value

[0073] Average energy / keV Protection ratio Index requirements 59.5 56.2％ ≥50％ 81 38.5％ ≥40％ 122 44.1％ ≥40％

[0074] The nuclear radiation protection material prepared in this embodiment 3 is different from the nuclear radiation protection material in embodiment 1. When the average energy is 59.5keV and 122keV, its protection ratio increases slightly, meeting the 50% requirement. As the proportion of tungsten powder decreases, its protection ratio decreases when the average energy is 81keV, and does not meet the protection ratio of 40%.

[0075] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0076] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a nuclear radiation protection material, characterized in that the process include: S1. Plastication: plasticize the natural rubber and chloroprene rubber respectively; S2, natural rubber mixing: adding sulfur, accelerator M, accelerator D, zinc oxide, stearic acid, carbon black, antioxidant A, bismuth powder, tungsten powder, and praseodymium oxide to the plasticized natural rubber for mixing and preparing a natural rubber compound; S3, chloroprene rubber mixing: adding magnesium oxide, stearic acid, carbon black, zinc oxide, accelerator NA-22, antioxidant D, rosin, and coumarone resin to the plasticized chloroprene rubber for mixing to prepare a chloroprene rubber mixture; S4. Cut the natural rubber compound and the chloroprene compound into particles with a particle size of ≤5 cm respectively, and dissolve them in an organic solvent to obtain a natural rubber compound slurry; apply, heat, dry and vulcanize to obtain a nuclear radiation material.

2. The method for preparing a nuclear radiation protection material according to claim 1, characterized in that: In S1, the mastication is performed at 60-100°C for 10-15 minutes.

3. The method for preparing a nuclear radiation protection material according to claim 1, characterized in that: In S2, the weight proportions of the components are 100 parts of natural rubber, 2-3 parts of sulfur, 1-1.5 parts of accelerator M, 0-1 parts of accelerator D, 4-6 parts of zinc oxide, 0.5-1.5 parts of stearic acid, 15-25 parts of carbon black, 0.5-1.5 parts of antioxidant A, 100-150 parts of bismuth powder, 40-60 parts of tungsten powder, and 20-40 parts of praseodymium oxide; Preferably, the composition comprises 100 parts of natural rubber, 2.5 parts of sulfur, 1.2 parts of accelerator M, 0.4 parts of accelerator D, 5 parts of zinc oxide, 1 part of stearic acid, 20 parts of carbon black, 1 part of antioxidant A, 120 parts of bismuth powder, 50 parts of tungsten powder and 30 parts of praseodymium oxide.

4. The method for preparing a nuclear radiation protection material according to claim 1, characterized in that: In S3, the weight proportions of the components are 100 parts of chloroprene rubber, 3-5 parts of magnesium oxide, 0-1 parts of stearic acid, 15-25 parts of carbon black, 4-6 parts of zinc oxide, 0-1 parts of accelerator NA-22, 0.5-1.5 parts of antioxidant D, 2-3 parts of rosin, and 2-3 parts of coumarone resin; Preferably, the composition comprises 100 parts of chloroprene rubber, 4 parts of magnesium oxide, 0.5 parts of stearic acid, 20 parts of carbon black, 5 parts of zinc oxide, 0.5 parts of accelerator NA-22, 1 part of antioxidant D, 2.5 parts of rosin and 2.5 parts of coumarone resin.

5. A method for preparing a nuclear radiation protection material according to any one of claims 1 to 4, characterized in that: The mixing temperature and time are 40-70°C for 30-40 minutes.

6. The method for preparing a nuclear radiation protection material according to claim 1, characterized in that: In S4, the natural rubber compound is dissolved in 120# solvent oil in a weight ratio of 1:(1.5-2.5) to prepare a natural rubber compound slurry; the chloroprene rubber compound is dissolved in toluene in a weight ratio of 1:3 to prepare a chloroprene compound slurry.

7. The method for preparing a nuclear radiation protection material according to claim 6, characterized in that: In S4, the coating is to coat at least one layer of adhesive on the base fabric, and each layer is heated and dried at a temperature of 80-100° C. for a drying time of 10-12 minutes, thereby obtaining a composite layer blank. Preferably, the front side of the base fabric is coated with one layer of chloroprene rubber mixed glue and five layers of natural rubber mixed glue from the inside to the outside; the back side of the base fabric is coated with one layer of chloroprene rubber mixed glue and five layers of natural rubber mixed glue from the inside to the outside; and the coating thickness of each glue is 0.05 mm; Preferably, the base fabric is polyester fiber.

8. The method for preparing a nuclear radiation protection material according to claim 7, characterized in that: In S4, the vulcanization is to place the composite layer blank at a temperature of 150-170°C and a vulcanization pressure of 20-40kg / cm 2 The sulfidation reaction is carried out in an environment for 10-15 minutes to obtain a nuclear radiation protection material; Preferably, the vulcanization temperature is 160°C and the vulcanization pressure is 30 kg / cm 2 , lasting 12 minutes.

9. The method for preparing a nuclear radiation protection material according to claim 7, characterized in that: In S4, before vulcanization, sodium stearate is sprayed on the front and back sides of the composite layer blank.

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