Radiation-proof material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of radiation protection materials, and relates to an anti-radiation material as well as a preparation method and application thereof. The material is a non-woven fabric containing a functional coating on the surface, and is obtained by taking 30-70 parts of polypropylene resin, 30-70 parts of a metal substance, 0.5-1 part of a coupling agent, 0.1-0.3 part of a lubricating agent, 3-5 parts of a compatilizer, 1-3 parts of a dispersing agent and 0.1-0.3 part of an antioxidant as main raw materials through two times of granulation, melt spinning of granules into cloth, surface pretreatment and dip-coating of the functional coating. Effective components of the functional coating liquid take a prepolymer, Prussian blue, isopropanol and PEG2000 as raw materials, and the prepolymer is obtained by mixing hexamethylene diisocyanate, castor oil, acetone and dibutyltin dilaurate according to a ratio and then carrying out a heating reaction. The material can effectively protect electron radiation rays, and no foreign matter falls off; the cesium ion aerosol can be adsorbed, the situation that the cesium ion aerosol is inhaled into a human body to generate internal radiation is prevented, and the cesium ion aerosol can be widely applied to masks, protective clothing, operating gowns, surgical drapes or surgical drapes as a raw material.

Description

Technical Field

[0001] The invention belongs to the technical field of radiation protection materials and relates to a radiation protection material and a preparation method and application thereof. Background Art

[0002] With the development of industrial production, national defense, medical treatment, electricity and other fields, the use of nuclear energy and radioactive sources has become more and more widespread. However, in the process of nuclear technology development and utilization, there are problems such as nuclear radiation and leakage of radioactive materials. These nuclear radiations will ionize materials and will seriously endanger human life and health if not protected.

[0003] Radioactive substances are radioactive isotopes. Their nuclei are unstable and prone to spontaneous changes in nuclear composition or energy state, transforming into another nuclide, while releasing one or more rays. Most of the rays emitted by nuclear radioactive substances are high-energy rays, mainly alpha rays, beta rays, X-rays, gamma rays, etc. The main ways for radioactive substances to enter and exit the human body are inhalation, ingestion, skin, mucous membranes, and wounds. Radioactive nuclides may enter the surrounding environment in liquid, gaseous or aerosol form, pollute the air, etc., and then enter the human body through the respiratory tract, digestive tract, skin or wounds. The radiation of radioactive substances is a type of ionizing radiation. On October 27, 2017, the World Health Organization's International Agency for Research on Cancer published a preliminary list of carcinogens for reference, and ionizing radiation (all types) is on the list of Class I carcinogens.

[0004] 137Cs accounts for a large proportion of the total amount of radioactive substances. It is an aerosol with a half-life of up to 30.17 years and can release beta rays and gamma rays. After 137Cs in the environment enters the human body, it is easily absorbed and evenly distributed throughout the body. It is mainly retained in the soft tissues of the whole body, especially in the muscles, and has a lower concentration in bones and fat. A large amount of radioactive cesium ingested into the body can cause acute and chronic injuries. Radioactive substances not only work locally, but also affect the entire body. Radioactive substances can cause damage to the central nervous system, neuro-endocrine system and blood system; they can change vascular permeability, leading to bleeding and concurrent infection. The above phenomenon seriously damages the body's life functions and stops life activities.

[0005] Large doses of radioactive substances can cause pathological changes quickly, but at low doses, these changes are slow and accompanied by a latent period of varying lengths. When the radiation dose is below 150rad, the mortality rate is zero, but it is not without harmful effects. It often takes 20 years for some symptoms to appear. Radioactivity can also damage genetic material, mainly by causing gene mutations and chromosomal aberrations, causing one or even several generations to suffer.

[0006] The development and application of radiation protection materials is to protect humans from or reduce the harm of ionizing radiation. Radiation protection products can effectively form a barrier between the radiation source and personnel, reduce the radiation dose to the human body, and achieve the purpose of shielding protection.

[0007] Patent document 202211239501.6 uses tungsten powder as the core powder, coats polydopamine on its surface, and uses the adsorption and deposition properties of polydopamine to prepare a shielding outer shell on its surface to prepare a composite shielding powder; adds it to a silicone-modified emulsion to prepare an impregnation liquid, and performs two dips and two rolls on the surface of the base fabric to achieve surface shielding protection finishing of the base fabric. The protective fabric prepared by this method has excellent X-ray protection performance and excellent protective shielding effect.

[0008] Patent document 201210534855.3: After electron beam or plasma pre-irradiation treatment, rare earth nanopowders are grafted onto the treated textiles; or rare earth nanopowders or rare earth salts are doped into the textiles and co-irradiated on the textiles by electron beam or plasma; and finally baked to obtain neutron protective fabrics.

[0009] Patent document 201510041324.4 provides a nuclear radiation proof composite flexible material, comprising: a non-woven fabric and a binder layer cross-linked and composited on the surface of the non-woven fabric; the non-woven fabric is made of polymer fibers and stainless steel fibers; the binder layer is formed by cross-linking an emulsion comprising acrylic resin PE resin, a cross-linking agent and water.

[0010] Patent document 201911304242.9 relates to an ionizing radiation protective suit. The protective suit includes an inner layer structure, an outer layer structure and an intermediate layer structure; the intermediate layer structure is a coating structure, and the coating used is composed of the following components and their weight parts: 40-50 parts of erbium oxide, 10-20 parts of bismuth oxide, 5-15 parts of nano titanium dioxide, 10-20 parts of water-soluble polyurethane, 20-30 parts of silicone gel, and 1-5 parts of polyethylene glycol. The protective suit of the present invention has excellent anti-ionizing radiation performance, especially anti-gamma ray performance.

[0011] Patent document 202211074776.9 discloses an ionizing radiation-proof sheath-core composite short fiber non-woven fabric and a preparation method thereof, which belongs to the technical field of nuclear radiation shielding material production. The non-woven fabric is mainly composed of material A and material B, wherein material A is a thermoplastic resin containing no or less shielding functional powder, and material B is a polymer containing more shielding functional powder. Material A is 10-50% by mass, of which 0-15% contains shielding functional powder, and material B is 50-90% by mass, of which 45-60% contains shielding functional powder. The present invention also relates to a method for preparing an ionizing radiation-proof sheath-core composite short fiber non-woven fabric. The short fiber non-woven fabric prepared by using the ionizing radiation-proof sheath-core composite short fiber non-woven fabric and its preparation method of the present invention has good nuclear radiation shielding performance.

[0012] Patent document 202110539545.X discloses a radioactive aerosol protective fabric and protective clothing, the radioactive aerosol protective fabric comprising a support layer, a barrier layer and a waterproof protective layer. The support layer has a radiation protection material. The barrier layers are fitted and connected in sequence, and the barrier layer and the support layer are fitted and connected; the barrier layer comprises an organic nanofiber layer, and N is 4-15. The waterproof protective layer is connected to the support layer or the barrier layer, and the waterproof protective layer comprises nylon cloth. The radioactive aerosol protective fabric of the present application is made of permeable material, is not easy to break, can block radioactive substances, and has good thermal physiological comfort, which meets the protection needs of workers in a nuclear radiation environment.

[0013] The prior art uses coating, grafting or blending methods to compound metals and their compounds with non-woven fabrics or fabrics to prepare radiation protection materials. Among them, the modified non-woven fabrics obtained by the blending method are prone to blockage and broken wires when the spinning die aperture is 0.20-0.35mm, which makes processing difficult. However, when the inorganic content is low, the protection effect of high-energy rays cannot meet the standard. Grafting or coating can only fill the surface of the non-woven fabric with inorganic materials, but the inside cannot be filled, and the radiation protection effect is not good. The processing technology of multi-layer composite and inorganic spraying in the middle is complicated, and the air permeability of the non-woven fabric is deteriorated and the processing cost is increased. Rubber and inorganic materials are blended and blended in an internal mixer, and the air permeability requirements of the product cannot be guaranteed. Most of the non-woven fabrics or products prepared by the invention only have a shielding effect on high-energy rays, but cannot protect aerogels in the air. Inhalation of the aerogel by the human body will also cause internal radiation, which is harmful to human health. Summary of the invention

[0014] Based on this, the object of the present invention is to provide a radiation protection material, which has an excellent shielding effect on radionuclide aerosols and high-energy rays.

[0015] The invention also provides a preparation method of the above material and application thereof.

[0016] To achieve the above object, the present invention adopts the following technical solutions: The invention provides a radiation protection material, comprising a non-woven fabric with a functional coating on the surface; the non-woven fabric comprises the following raw materials in parts by weight: 30-70 parts of polypropylene resin, 30-70 parts of metal substances, 0.5-1 parts of coupling agents, 0.1-0.3 parts of lubricants, 3-5 parts of compatibilizers, 1-3 parts of dispersants, and 0.1-0.3 parts of antioxidants; the raw materials are calculated in parts by weight.

[0017] Furthermore, the polypropylene resin has an isotactic index of 95%-99%, a melt index of 30-40 g / 10 min, a tensile elastic modulus of ≥1100 MPa, and a tensile breaking strain of ≥450%.

[0018] Furthermore, the metal substance has an average particle size of 1-5 μm and includes metals and / or metal compounds, the metal includes any one or more of tungsten, bismuth and samarium, and the metal compound includes any one or more of tungsten chloride, tungsten oxide, bismuth oxide and samarium oxide; the preferred metal substance is composed of tungsten powder and bismuth oxide or tungsten powder and samarium oxide, wherein the tungsten content is greater than 80%.

[0019] Furthermore, the compatibilizer includes maleic anhydride grafted PP, the grafting rate of the maleic anhydride grafted PP is 0.3-0.9%, and the melt index is 15-25g / 10min.

[0020] Furthermore, the dispersant includes liquid paraffin, preferably light liquid paraffin; the coupling agent includes isopropyl tri(dioctyl pyrophosphate) titanate or γ-(2,3-epoxypropoxy)propyltrimethoxysilane; the lubricant includes N-octadecyl-13-behenamide; the antioxidant includes a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 3:7-7:3, and the preferred mass ratio is 1:1.

[0021] The present invention further provides a method for preparing a radiation protection material, comprising the following steps: S1, primary granulation: mixing part of the metal substance and part of the dispersant with the remaining raw materials and then extruding and granulating; S2, secondary granulation: the granules in S1 are mixed with the remaining metal material and the remaining dispersant and then extruded and granulated; S3, preparation of non-woven fabric: melting and spinning the pellets in S2, blowing and stretching, web forming and hot rolling, slitting and winding to obtain non-woven fabric; S4, non-woven fabric dip coating: the non-woven fabric in S3 is dipped into the functional coating liquid after surface pretreatment, and the radiation protection material is obtained after drying.

[0022] Furthermore, the primary granulation described in S1 is to first mix the polypropylene resin and the compatibilizer to obtain A, mix 60%-80% of the total amount of the metal substance, the lubricant and the antioxidant to obtain B, then add 60%-80% of the total amount of the dispersant and the coupling agent to A in sequence and mix them to obtain C, and finally add B to C, mix them and extrude them for granulation.

[0023] Furthermore, the extrusion granulation processing parameters in S1 and S2 are: the extrusion granulation processing parameters in S1 and S2 are: zone one temperature 175℃±5℃, zone two temperature 185℃±5℃, zone three temperature 190℃±5℃, zone four temperature 190℃±5℃, zone five temperature 205℃±5℃, zone six temperature 205℃±5℃, die head temperature 195℃±5℃, the die mouth filter is double-layer, and the mesh sizes of the double-layer filter are 50±10 mesh and 100±10 mesh respectively.

[0024] Further, it is characterized in that the non-woven fabric preparation process parameters in S3 are: the temperature of zone 1 is 190℃±5℃, the temperature of zone 2 is 210℃±5℃, the temperature of zone 3 is 225℃±5℃, the temperature of zone 4 is 225℃±5℃, the temperature of zone 5 is 230℃±5℃, the temperature of die head is 220℃±5℃, the die mouth filter is three-layer, the mesh numbers of the three-layer filter are 50±10 mesh, 50±10 mesh, and 120±10 mesh from top to bottom, respectively, and there is a gap between each layer of the filter, and the gap height is 0.3-0.6mm. The height of the gap between each layer is the same or different, and preferably the gap height between each layer is the same.

[0025] Further, the surface pretreatment method in S4 includes corona treatment or plasma treatment, preferably corona treatment, and the corona treatment voltage is 10000-20000V / m 2 , frequency is 10-30 kHz; the dipping time is 0.5-3min, preferably 1min, and the drying temperature is 80-120℃.

[0026] Furthermore, the functional coating liquid in S4 contains 10-40% by mass of an active ingredient and 60-90% by mass of a diluent; the active ingredient is obtained by mixing 10-30 parts of a prepolymer, 4-10 parts of Prussian blue, 0.5 parts of isopropanol and 0.5-2 parts of PEG20000 as raw materials, and the prepolymer is mixed with hexamethylene diisocyanate, castor oil, acetone and dibutyltin dilaurate in a ratio of 1-2:2-4:0.7-1.0:0.003-0.005, preferably in a ratio of 1:2:0.8:0.004, and obtained by heating reaction; the raw materials are measured in parts by weight.

[0027] Furthermore, the castor oil in S4 is used after being subjected to vacuum drying and dehydration treatment at 80°C-110°C for 8-10 hours, and the acetone and isopropanol are added to a dry molecular sieve to remove water for 24 hours before use; the hexamethylene diisocyanate, castor oil, acetone and dibutyltin dilaurate are mixed in proportion, and reacted at a constant temperature of 80±5°C for 3-5 hours under nitrogen protection to obtain the prepolymer; the prepolymer, Prussian blue, isopropanol and PEG2000 are mixed in a homogenizer at a speed of 8000-130000 rpm to obtain the effective ingredient.

[0028] The present invention further provides a radiation protection composite material having a layered structure, which is obtained by compounding the radiation protection material with a non-woven fabric and / or a melt-blown fabric, wherein the number of composite layers of the non-woven fabric and the melt-blown fabric is ≥1.

[0029] Finally, the present invention provides an application of the radiation protection material as a raw material in masks, protective clothing, surgical gowns, surgical sheets or surgical drapes.

[0030] The beneficial effects of the present invention are: 1. The radiation protection material provided by the present invention can effectively protect against electronic radiation rays by selecting appropriate blending aids and compound formulas, and contains a functional coating, without foreign matter falling off, reducing the risk of foreign matter being inhaled into the human body; it can adsorb cesium ion aerosols to prevent the aerosols of radiation ions from being inhaled into the human body and causing internal radiation. The cell survival rate of the material is more than 80% after cytotoxicity testing, and it is safe and non-toxic. The material can be widely used as a raw material in masks, protective clothing, surgical gowns, surgical sheets or surgical drapes.

[0031] 2. The preparation method of the radiation protection material provided by the present invention, by selecting the appropriate number of filter layers and pore size, the gap between the filter screens, the spinning process, and especially the secondary granulation step, can make the metal material with a diameter of 1-5 μm evenly dispersed in the plastic during granulation, and can be continuously spun through a 0.2-0.35 mm pore size spinning die. The maximum filling amount in the spinning bundle can reach 70%, which can effectively protect against radiation while reducing air resistance and ensuring the high air permeability of the non-woven fabric.

[0032] 3. The radiation-proof composite material provided by the present invention has the functions of filtering and shielding radiation, and can also ensure high air permeability and maintain breathability and comfort when used in protective products. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Attached Figure 1 This is a test diagram of the radiation protection material morphology in Example 1; Attached Figure 2 This is a diagram of the layered structure of the radiation protection composite material; Attached Figure 3 This is the X-ray shielding effect diagram of radiation protection composite material. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. The embodiments mentioned are all implemented on the premise of the technical solutions of the present invention, and detailed implementation processes are given, but it should be stated that the protection scope of the present invention is not limited to the following embodiments.

[0036] The radiation protection material provided by the present invention is a non-woven fabric with a functional coating on the surface, which is obtained by granulating twice, melt-spinning the pellets into cloth, pre-treating the surface and dipping the functional coating with 30-70 parts of polypropylene resin, 30-70 parts of metal substances, 0.5-1 parts of coupling agents, 0.1-0.3 parts of lubricants, 3-5 parts of compatibilizers, 1-3 parts of dispersants and 0.1-0.3 parts of antioxidants as main raw materials; the effective components of the functional coating liquid are prepolymer, Prussian blue, isopropanol and PEG2000 as raw materials, wherein the prepolymer is obtained by mixing hexamethylene diisocyanate, castor oil, acetone and dibutyltin dilaurate in proportion and then heating and reacting.

[0037] The raw materials used in the embodiments and comparative examples are described below, but are not limited to these raw materials. The raw materials in the present invention can be directly commercially available raw materials: The isotactic index of the polypropylene resin is 95%-99% of the mass fraction, the melt index is 30-40g / 10min, the tensile elastic modulus is ≥1100MPa, and the tensile fracture strain is ≥450%. The isotactic index of the polypropylene resin used in Examples 1-3 is 97%, and the melt index is 35 g / 10min. The average particle size of the metal substance is 1-5μm, and the preferred metal substance is composed of tungsten powder and bismuth oxide or tungsten powder and samarium oxide, wherein the tungsten content is greater than 80%. The compatibilizer includes maleic anhydride grafted PP, the grafting rate of maleic anhydride grafted PP is 0.3-0.9%, and the melt index is 15-25g / 10min. The grafting rates of maleic anhydride grafted PP used in Examples 1-3 are 0.4%, 0.6% and 0.8%, respectively, and the melt index is 20 g / 10min. The dispersant includes liquid paraffin, preferably light liquid paraffin; the coupling agent includes isopropyl tri(dioctyl pyrophosphate acyloxy) titanate or γ-(2,3-epoxypropoxy)propyl trimethoxy silane; the lubricant includes N-octadecyl-13-behenamide; the antioxidant includes a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 3:7-7:3, and the preferred mass ratio is 1:1.

[0038] The radiation protection composite material can be obtained by compounding the radiation protection material with non-woven fabric and / or melt-blown fabric, and has a layered structure, wherein the number of composite layers of non-woven fabric and melt-blown fabric is ≥1, and the gram weight of the non-woven fabric is preferably 25g / m 2 The preferred weight of meltblown fabric is 13-15 g / m 2 .

[0039] Radiation protection materials can effectively protect against electronic radiation without foreign matter falling off; they can absorb cesium ion aerosols to prevent aerosols from being inhaled into the human body to produce internal radiation. Radiation protection materials or radiation protection composite materials can be widely used as raw materials in masks, protective clothing, surgical gowns, surgical sheets or surgical drapes.

[0040] Example 1 The preparation of radiation protection material comprises the following steps: (1) Add 30 kg of polypropylene resin and 3 kg of maleic anhydride grafted PP into a high-speed mixer, then pour in 2.1 kg of liquid paraffin and mix evenly in the high-speed mixer; (2) Add 1 kg of isopropyl tri(dioctyl pyrophosphate) titanate to step (1) and mix well in a high-speed mixer; (3) 49 kg of tungsten powder, 0.3 kg of N-octadecyl-13-behenamide, 0.05 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 0.05 kg of tris(2,4-di-tert-butylphenyl) phosphite were mixed evenly, added to step (2), and mixed evenly in a high-speed mixer; (4) The mixture obtained in step (3) is pelletized in an extruder with the following processing parameters: The temperature of zone 1 is 175℃, the temperature of zone 2 is 185℃, the temperature of zone 3 is 190℃, the temperature of zone 4 is 190℃, the temperature of zone 5 is 205℃, the temperature of zone 6 is 205℃, the temperature of die head is 195℃, the filter screen at the die mouth is double-layer, the mesh numbers of the filter screen are 50 mesh and 100 mesh respectively, and the pellets are obtained by extruder processing; (5) First add 0.9 kg of liquid paraffin to the pellets obtained in step (4) in a high-speed mixer and mix evenly, then add 21 kg of tungsten powder and mix evenly. Then repeat the process parameters of step (4) to process and granulate to obtain the final pellets; (6) The pellets obtained in step (5) are melt-spun on a non-woven fabric machine with the following processing parameters: The temperature of zone 1 is 190℃, the temperature of zone 2 is 210℃, the temperature of zone 3 is 225℃, the temperature of zone 4 is 225℃, the temperature of zone 5 is 230℃, the temperature of die head is 220℃, the filter screen is three layers, the mesh numbers from top to bottom are: 50 mesh, 50 mesh, 120 mesh, there is a gap between each layer of the filter screen, the gap height is 0.3mm; (7) The spinneret is blown and stretched, hot rolled into a web, and slit and rolled to obtain a non-woven fabric; (8) The non-woven anti-radiation layer prepared in step (7) is subjected to corona treatment at a voltage of 15000 V / m 2 , frequency is 20 kHz; (9) The castor oil was dried and dehydrated at 80°C in vacuum for 9 hours, and acetone and isopropanol were added to a dry molecular sieve to remove water for 24 hours; (10) adding hexamethylene diisocyanate, castor oil treated in step (9), acetone, and dibutyltin dilaurate into a reaction kettle in a ratio of 10:20:8:0.04, protecting with nitrogen, stirring at a constant speed, slowly heating to 80° C., and reacting for 4 hours at a constant temperature to obtain a prepolymer; (11) Add 20 parts of the prepolymer prepared in step (10), 8 parts of Prussian blue, 0.5 parts of isopropanol, and 1.5 parts of PEG2000 into a homogenizer and mix them evenly. The speed of the homogenizer is 13,000 rpm. Add acetone to the homogenous mixture for dilution. The mixed solution accounts for 30% of the total weight of the coating solution. A final coating solution is obtained. (12) The surface-treated non-woven fabric obtained in step (8) is immersed in the functional coating in step (11), and dried in an oven at 80-120° C. to obtain a radiation protection material.

[0041] Example 2 The preparation of radiation protection material comprises the following steps: (1) Add 70 kg of polypropylene resin and 5 kg of maleic anhydride grafted PP into a high-speed mixer, then pour in 0.7 kg of liquid paraffin and mix evenly in the high-speed mixer; (2) Add 0.5 kg of γ-(2,3-epoxypropoxy)propyltrimethoxysilane to step (1) and mix well in a high-speed mixer; (3) 18 kg of tungsten powder, 3 kg of samarium oxide, 0.1 kg of N-octadecyl-13-behenamide, 0.05 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 0.05 kg of tris(2,4-di-tert-butylphenyl) phosphite were mixed evenly, and then added to step (2), and mixed evenly in a high-speed mixer; (4) The mixture obtained in step (3) is pelletized in an extruder with the following processing parameters: The temperature of zone 1 is 178°C, the temperature of zone 2 is 186°C, the temperature of zone 3 is 192°C, the temperature of zone 4 is 191°C, the temperature of zone 5 is 206°C, the temperature of zone 6 is 207°C, the temperature of die head is 197°C, the die mouth filter is double-layer, the filter mesh numbers are 50 mesh and 100 mesh respectively, and the pellets are obtained by extruder processing; (5) First add 0.3 kg of liquid paraffin to the pellets obtained in step (4) in a high-speed mixer and mix evenly, then add 9 kg of tungsten powder and mix evenly. Then repeat the process parameters of step (4) to process and granulate to obtain the final pellets; (6) The pellets obtained in step (5) are melt-spun on a non-woven fabric machine with the following processing parameters: The temperature of zone 1 is 191℃, the temperature of zone 2 is 211℃, the temperature of zone 3 is 223℃, the temperature of zone 4 is 227℃, the temperature of zone 5 is 234℃, the temperature of die head is 224℃, the filter screen is three-layer, the mesh numbers from top to bottom are: 50 mesh, 50 mesh, 120 mesh, there is a gap between each layer of the filter screen, the gap height is 0.5mm; (7) The spinneret is blown and stretched, hot rolled into a web, and slit and rolled to obtain a non-woven fabric; (8) The non-woven anti-radiation layer prepared in step (7) is subjected to corona treatment at a voltage of 11000 V / m 2 , frequency is 15 kHz; (9) The castor oil was dried and dehydrated at 80°C in vacuum for 9 hours, and acetone and isopropanol were added to a dry molecular sieve to remove water for 24 hours; (10) adding hexamethylene diisocyanate, castor oil treated in step (9), acetone, and dibutyltin dilaurate into a reaction kettle in a ratio of 10:20:8:0.04, protecting with nitrogen, stirring at a constant speed, slowly heating to 80° C., and reacting for 4 hours at a constant temperature to obtain a prepolymer; (11) Add 30 parts of the prepolymer prepared in step (10), 10 parts of Prussian blue, 0.5 parts of isopropanol, and 2 parts of PEG2000 into a homogenizer and mix them evenly. The speed of the homogenizer is 12000 rpm. Add acetone into the homogenous mixture for dilution. The mixed solution accounts for 20% of the total weight of the coating liquid. A final coating liquid is obtained. (12) The surface-treated non-woven fabric obtained in step (8) is immersed in the functional coating in step (11), and dried in an oven at 80-120° C. to obtain a radiation protection material.

[0042] Example 3 The preparation of radiation protection material comprises the following steps: (1) Add 50 kg of polypropylene resin and 5 kg of maleic anhydride grafted PP into a high-speed mixer, then pour in 1.4 kg of liquid paraffin and mix evenly in the high-speed mixer; (2) Add 0.8 kg of isopropyl tri(dioctyl pyrophosphate) titanate to step (1) and mix well in a high-speed mixer; (3) 30 kg of tungsten powder, 5 kg of bismuth oxide, 0.3 kg of N-octadecyl-13-behenamide, 0.075 kg of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and 0.075 kg of tris(2,4-di-tert-butylphenyl) phosphite were mixed evenly, added to step (2), and mixed evenly in a high-speed mixer; (4) The mixture obtained in step (3) is pelletized in an extruder with the following processing parameters: The temperature of zone 1 is 179°C, the temperature of zone 2 is 183°C, the temperature of zone 3 is 192°C, the temperature of zone 4 is 193°C, the temperature of zone 5 is 207°C, the temperature of zone 6 is 206°C, the temperature of die head is 196°C, the filter screen at the die mouth is double-layer, the mesh numbers of the filter screen are 50 mesh and 100 mesh respectively, and the pellets are obtained by extruder processing; (5) First add 0.6 kg of liquid paraffin to the pellets obtained in step (4) in a high-speed mixer and mix evenly, then add 15 kg of tungsten powder and mix evenly. Then repeat the process parameters of step (4) to process and granulate to obtain the final pellets; (6) The pellets obtained in step (5) are melt-spun on a non-woven fabric machine with the following processing parameters: The temperature of zone 1 is 187℃, the temperature of zone 2 is 208℃, the temperature of zone 3 is 228℃, the temperature of zone 4 is 224℃, the temperature of zone 5 is 232℃, the temperature of die head is 220℃, the filter screen is three-layer, the mesh numbers of the filter screen from top to bottom are: 50 mesh, 50 mesh, 120 mesh, there is a gap between each layer of the filter screen, the gap height is 0.6mm; (7) The spinneret is blown and stretched, hot rolled into a web, and slit and rolled to obtain a non-woven fabric; (8) The non-woven anti-radiation layer prepared in step (7) is subjected to corona treatment at a voltage of 13000 V / m 2 , frequency is 18 kHz; (9) The castor oil was dried and dehydrated at 80°C in vacuum for 9 hours, and acetone and isopropanol were added to a dry molecular sieve to remove water for 24 hours; (10) adding hexamethylene diisocyanate, castor oil treated in step (9), acetone, and dibutyltin dilaurate into a reaction kettle in a ratio of 10:20:8:0.04, protecting with nitrogen, stirring at a constant speed, slowly heating to 80° C., and reacting for 4 hours at a constant temperature to obtain a prepolymer; (11) Add 10 parts of the prepolymer prepared in step (10), 4 parts of Prussian blue, 0.5 parts of isopropanol, and 0.5 parts of PEG2000 into a homogenizer and mix them evenly. The speed of the homogenizer is 11000 rpm. Add acetone to the homogenous mixture for dilution. The mixed solution accounts for 10% of the total weight of the coating liquid. A final coating liquid is obtained. (12) The surface-treated non-woven fabric obtained in step (8) is immersed in the functional coating in step (11), and dried in an oven at 80-120° C. to obtain a radiation protection material.

[0043] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that 14 kg of tungsten powder is added in step (3), 6 kg of tungsten powder is added in step (5), and after the non-woven fabric is obtained in step (7), no pretreatment and coating process are performed, and the mask sample is directly obtained according to step (13).

[0044] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the mesh numbers of the die filter screens used in step (4) are 100 mesh and 50 mesh respectively, and the filter screens in step (6) are three layers, with the mesh numbers from top to bottom being 120 mesh, 50 mesh, and 50 mesh respectively, and a gap is left between each layer of the filter screen, and the gap height is 0.1 mm.

[0045] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that step (4) and step (5) are combined into one, and secondary granulation is not performed.

[0046] Implementation effect analysis In the present invention, Comparative Examples 1-3 all correspond to Example 1. Comparative Example 1 does not perform pretreatment and coating processes. Comparative Example 2 has different filter screen specifications and models, which will lead to unstable spinning and frequent wire breakage during the production process, especially when there is no gap between the filter screens, the extrusion pressure of the equipment increases, and the hole blockage is serious. Comparative Example 3 does not perform secondary granulation, so the metal compound cannot be evenly dispersed, and frequent wire breakage occurs during the production process, resulting in low production efficiency and huge production costs.

[0047] The radiation protection material in Example 1 was tested by scanning electron microscope to observe the dispersion of metal substances in the polypropylene resin matrix. The results are as follows: Figure 1 As shown in the figure, the white spherical particles are metal substances, and the dark background color is the polypropylene resin matrix. The metal substances are well combined with the matrix and are evenly dispersed.

[0048] The radiation protection materials in Examples 1-3 are Figure 2 In the manner shown, the non-woven fabric layer and the melt-blown fabric layer are laminated to obtain a radiation-proof composite material. Figure 2 In the composite method, the radiation protection material is replaced with the material obtained in Comparative Example 1 to obtain a composite material, which is used as a control sample. The radiation protection composite material and the control sample are tested for safety, aerosol shielding effect and X-ray shielding effect, respectively, and the test results are shown in the following table.

[0049] Safety test: Cytotoxicity test was conducted according to GB-16886.

[0050] Aerogel shielding effect test: Place the sample in an environment with a relative humidity of 85±5% and a temperature of 38±2.5℃ for 25±1h for pretreatment; then place it in an environment with a relative humidity of 30±10% and a temperature of 25±5℃, cesium chloride aerosol [particle number median diameter (CMD)]: 0.075±0.020μm; the geometric standard deviation of particle distribution is ≤1.86, and the concentration is ≤200 mg / m 3 The test was carried out in an environment with an air flow rate of 30 ± 2 L / min and a cross-sectional area of ​​100 cm 3 , for continuous testing.

[0051] X-ray shielding effect test: The radiation shielding composite material was tested under a portable X-ray instrument. The results are as follows: Figure 3 As shown in the figure, an opaque black area appears, indicating that the radiation protection composite material can effectively block X-rays and has a significant shielding effect on X-rays. Under the conditions of temperature 20.3℃, relative humidity 25%, and air pressure 94.5kPa, the X-ray shielding efficiency of the sample was measured in accordance with "GBZ / T147-2002 Determination of attenuation performance of X-ray protection materials".

[0052] As can be seen from the table, the radiation-proof material prepared by the preparation method provided by the present invention, by selecting suitable blending aids and compounding formulas, contains a functional coating at the same time, giving the material excellent safety and radiation protection performance. Among them, the X-ray shielding efficiency can reach up to 92%, which can effectively protect the electron radiation rays, and no foreign matter falls off, reducing the risk of foreign matter being inhaled into the human body; it can adsorb cesium ion aerosols, and the filtration efficiency can reach up to more than 96%, which can effectively prevent the aerosol of radiation ions from being inhaled into the human body to cause internal radiation. The material has been tested for cytotoxicity, and the cell survival rate is more than 80%, which is safe and non-toxic. The material can be widely used as a raw material in masks, protective clothing, surgical gowns, surgical sheets or surgical drapes, which can effectively block the high-energy rays in the atmosphere from causing external radiation to the human body, and prevent the human body from being damaged by high-energy radiation for a long time in a radiation environment. Especially when applied to radiation-proof masks, it can effectively filter out aerosol ions containing radiation in the environment to prevent long-term inhalation and accumulation in the human body to cause internal radiation damage. A radiation-proof composite material can be obtained by compounding radiation-proof material with non-woven fabric and / or melt-blown fabric. This material has the function of filtering and shielding radiation while ensuring high air permeability. When used in protective products, it can maintain breathability and comfort.

[0053] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those 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 radiation protection material, characterized in that: The invention comprises a non-woven fabric with a functional coating on the surface; the non-woven fabric comprises the following raw materials in parts by weight: 30-70 parts of polypropylene resin, 30-70 parts of metal substances, 0.5-1 parts of coupling agents, 0.1-0.3 parts of lubricants, 3-5 parts of compatibilizers, 1-3 parts of dispersants, and 0.1-0.3 parts of antioxidants; the raw materials are measured in parts by weight.

2. The radiation protection material according to claim 1, characterized in that: The polypropylene resin has an isotactic index of 95%-99%, a melt index of 30-40 g / 10 min, a tensile elastic modulus of ≥1100 MPa, and a tensile breaking strain of ≥450%.

3. The radiation protection material according to claim 1, characterized in that: The compatibilizer includes maleic anhydride grafted PP, the grafting rate of the maleic anhydride grafted PP is 0.3-0.9%, and the melt index is 15-25g / 10min.

4. The radiation protection material according to claim 1, characterized in that: The metal substance has an average particle size of 1-5 μm and includes metals and / or metal compounds. The metal includes any one or more of tungsten, bismuth and samarium. The metal compound includes any one or more of tungsten chloride, tungsten oxide, bismuth oxide and samarium oxide.

5. The radiation protection material according to claim 1, characterized in that: The dispersant includes liquid paraffin; the coupling agent includes isopropyl tri(dioctyl pyrophosphate acyloxy) titanate or γ-(2,3-epoxypropoxy)propyl trimethoxy silane; the lubricant includes N-octadecyl-13-behenamide; and the antioxidant includes a mixture of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and tris(2,4-di-tert-butylphenyl) phosphite in a mass ratio of 3:7-7:

3.

6. A method for preparing the radiation protection material according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, primary granulation: mixing part of the metal substance and part of the dispersant with the remaining raw materials and then extruding and granulating; S2, secondary granulation: the granules in S1 are mixed with the remaining metal material and the remaining dispersant and then extruded and granulated; S3, preparation of non-woven fabric: melting and spinning the pellets in S2, blowing and stretching, web forming and hot rolling, slitting and winding to obtain non-woven fabric; S4, non-woven fabric dip coating: the non-woven fabric in S3 is dipped into the functional coating liquid after surface pretreatment, and the radiation protection material is obtained after drying.

7. The preparation method according to claim 6, characterized in that: The primary granulation described in S1 is to first mix the polypropylene resin and the compatibilizer to obtain A, mix 60%-80% of the total amount of the metal substance, the lubricant and the antioxidant to obtain B, then add 60%-80% of the total amount of the dispersant and the coupling agent to A in turn and mix them to obtain C, and finally add B to C, mix them and extrude them for granulation.

8. The preparation method according to claim 6, characterized in that: The extrusion granulation processing parameters in S1 and S2 are: zone one temperature 175℃±5℃, zone two temperature 185℃±5℃, zone three temperature 190℃±5℃, zone four temperature 190℃±5℃, zone five temperature 205℃±5℃, zone six temperature 205℃±5℃, die head temperature 195℃±5℃, the die mouth filter is double-layer, and the mesh sizes of the double-layer filter are 50±10 mesh and 100±10 mesh, respectively.

9. The preparation method according to claim 6, characterized in that: The process parameters for preparing the non-woven fabric in S3 are as follows: temperature of zone 1 is 190°C±5°C, temperature of zone 2 is 210°C±5°C, temperature of zone 3 is 225°C±5°C, temperature of zone 4 is 225°C±5°C, temperature of zone 5 is 230°C±5°C, temperature of die head is 220°C±5°C, the die mouth filter is three-layered, the mesh numbers of the three-layer filter are 50±10 mesh, 50±10 mesh, and 120±10 mesh from top to bottom, respectively, there is a gap between each layer of the filter, and the gap height is 0.3-0.6mm.

10. The preparation method according to claim 6, characterized in that: The functional coating liquid in S4 contains 10-40% by mass of an effective ingredient and 60-90% by mass of a diluent; the effective ingredient is obtained by mixing 10-30 parts of a prepolymer, 4-10 parts of Prussian blue, 0.5 parts of isopropanol and 0.5-2 parts of PEG2000 as raw materials, and the prepolymer is mixed with hexamethylene diisocyanate, castor oil, acetone and dibutyltin dilaurate in a ratio of 1-2:2-4:0.7-1.0:0.003-0.005, and is obtained by reacting at a constant temperature of 80±5°C for 3-5 hours under nitrogen protection; the raw materials are measured in parts by weight.

11. A radiation protection composite material, characterized in that: It has a layered structure and is obtained by compounding the radiation protection material according to any one of claims 1 to 5 with a non-woven fabric and / or a meltblown fabric, wherein the number of composite layers of the non-woven fabric and the meltblown fabric is ≥1.

12. Use of the radiation protection material according to any one of claims 1 to 5 as a raw material in masks, protective clothing, surgical gowns, surgical sheets or surgical drapes.

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