Low-cost X-ray protection material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of X-ray protection materials, and provides a low-cost X-ray protection material and a preparation method and application thereof. The protective material comprises the following components in parts by weight: 15-60 parts of modified silicon resin, 40-80 parts of functional powder and 0.01-1 part of a catalyst, the preparation method comprises the following steps: performing high-temperature molecular distillation devolatilization on the modified silicon resin, and fully mixing and shearing to obtain a uniform and stable matrix material; mixing the modifier with the functional powder, and after reacting for a period of time, coating the modifier on the surface of the functional powder to obtain modified functional powder; uniformly mixing a base material, the modified functional powder and a Karst platinum catalyst, and performing defoaming and pouring to obtain a protective material; the invention also provides a protective product. The protective product comprises the protective material. The composite material can meet the irradiation performance requirements of X rays, gamma rays and the like, and is good in comprehensive performance, good in flexibility, high in ductility, lead-free and non-toxic.

Description

Technical Field

[0001] The present invention relates to the technical field of X-ray shielding materials, and in particular to a low-cost X-ray shielding material and a preparation method and application thereof. Background Art

[0002] With the rapid development of the nuclear industry and the application of nuclear technology, the accompanying development of radiation shielding has garnered widespread attention, attracted significant investment and scientific research, and yielded a series of impressive results. In recent years, traditional X-ray shielding materials, primarily lead and lead compounds, have faced increasingly serious and difficult-to-solve challenges, such as heavy weight, high toxicity, and recycling difficulties. These products are gradually being replaced by new lead-free shielding materials. These materials, primarily based on a specific matrix material and doped with nano- and micron-sized rare earth functional particles such as bismuth oxide, yttrium oxide, europium oxide, and germanium oxide, have gained significant market recognition for their excellent radiation protection and overall performance. However, the high raw material and manufacturing costs of these materials have limited their potential for development, forcing them to forgo certain market segments in the shielding field.

[0003] Based on this, the traditional high-cost protective materials have greatly limited their practical application and engineering. Therefore, there is an urgent need for a low-cost and high-performance radiation protection material. Summary of the Invention

[0004] The purpose of the present invention is to provide a low-cost X-ray protection material and its preparation method and application. The material uses a specific silicone resin that is environmentally friendly and has good comprehensive performance as a matrix material. By doping functional powders with certain radiation shielding efficiency to replace the current expensive rare earth powders, a new low-cost radiation shielding material is prepared that meets the radiation performance requirements of X-rays, gamma rays, etc., has good comprehensive performance, good softness, high ductility, is lead-free and non-toxic, and can be flexibly applied.

[0005] The embodiments of the present invention are achieved through the following technical solutions:

[0006] The present invention provides a low-cost X-ray shielding material, which comprises the following components by weight: 15-60 parts of modified silicone resin, 40-80 parts of functional powder, and 0.01-1 part of catalyst.

[0007] The modified silicone resin is one or more of boron-containing silicone resin, silicone resin with low rigid group content or hydrogen-containing silicone resin;

[0008] The functional powder includes one or more of bismuth, barium, lanthanum, gadolinium, tantalum, tungsten and their compounds (such as oxides);

[0009] The catalyst is a Custer platinum catalyst.

[0010] Furthermore, the boron-containing silicone resin is a silicone resin in which a boron element is introduced into the silicon-oxygen main chain, and its preparation method is as follows: using methylboric acid or phenylboric acid as a boron source, an acid (such as concentrated sulfuric acid, trifluoromethanesulfonic acid, etc.) as a catalyst, and adding a certain proportion of silane (methyldichlorosilane, dimethyldichlorosilane, hexamethyldisiloxane or divinyltetramethylsiloxane) in a certain solvent system to prepare the boron-containing silicone resin; wherein the mass ratio of the boron source, the catalyst, and the silane is 3-10:1:1-5.

[0011] By introducing boron into silicone resin for modification, boron atoms are embedded in the silicon-oxygen main chain (such as boron-doped silicone resin BSR) through Si-OB bonds to form a cross-linked network; this structure inhibits the breakage of the main chain at high temperatures and maintains structural integrity; and the synergistic effect of boron and silicon-oxygen chains can regulate surface energy and improve the wettability of functional powders and resins, thereby achieving better compatibility. In addition, the neutron capture cross section of the boron element and the synergistic effect of the functional powder greatly improve the neutron shielding efficiency of the composite material.

[0012] Furthermore, the silicone resin with low rigid group content is a silicone resin with a low molar content of rigid groups (such as phenyl, biphenyl, etc.) introduced into the side chain, and its preparation method is as follows: using phenylsiloxane or phenylchlorosilane as a benzene source, an acid (such as concentrated sulfuric acid, trifluoromethanesulfonic acid, etc.) as a catalyst, adding methyltrimethoxysilane and dimethyldimethoxysilane in a certain solvent system, and performing a hydrolysis polymerization reaction to obtain a silicone resin with a low phenyl content; wherein the mass ratio of the benzene source, the catalyst, the methyltrimethoxysilane, and the dimethyldimethoxysilane is 1-3:1:5-10:5-10.

[0013] By introducing rigid groups such as phenyl and biphenyl, the cross-linking density and conjugation effect of silicone resin are increased, and the thermal stability and mechanical properties are significantly improved. In addition, the polarity of the rigid group (such as the π electrons of the benzene ring) enhances the interaction between silicone resin and functional powder, enhances the interfacial bonding strength, and the hydrophobicity regulation of the rigid side chain improves the wettability and dispersibility of the functional powder, thereby making the dispersion with the matrix material, i.e., the modified silicone resin, more uniform and with higher bonding strength. This is mainly due to the rigid group increasing the molecular chain spacing and reducing the agglomeration effect of the functional powder. In addition, the biphenyl group and the neutron capture cross section of the functional powder synergize to significantly improve the X-ray shielding efficiency of the composite material.

[0014] Furthermore, the hydrogenated silicone resin is a low molecular weight methyl vinyl silicone resin containing branched vinyl groups, a branched hydrogenated silicone resin, such as DY-V411 vinyl silicone oil (branched type), high hydrogenated silicone oil (branched type) or methyl hydrogenated MQ silicone resin.

[0015] The present invention provides a method for preparing a low-cost X-ray shielding material, comprising the following steps:

[0016] S1. Pretreatment of modified silicone resin: After high-temperature molecular distillation and devolatilization at 100-200°C, the modified silicone resin is added to a reactor and thoroughly mixed and sheared to obtain a uniform and stable high-temperature resistant matrix material;

[0017] S2. Functional powder dispersion: The modifier is mixed with the functional powder, and after a period of reaction, the modifier is coated on the surface of the functional powder to obtain a modified functional powder; specifically, the modifier is: a coupling agent, a surfactant or a polymer;

[0018] S3. After uniformly mixing the base material obtained in S1, the modified functional powder obtained in S2 and the catalyst, degassing and pouring are performed to obtain a protective material.

[0019] More specifically, in S2, with respect to the modification method of functional powders using different modifiers, the present invention provides a coupling agent modification method:

[0020] First, the catalyst is added to a solvent (such as anhydrous ethanol) and stirred evenly, and then a coupling agent is added and stirred at room temperature for 30 minutes for hydrolysis activation to obtain a hydrolysis coupling agent solution;

[0021] Then, the functional powder was added to the solvent and ultrasonically dispersed for 20 minutes to obtain a functional powder suspension;

[0022] Subsequently, the hydrolysis coupling agent solution is slowly added to the dispersed functional powder suspension, and stirred at a speed of 300r / min in a constant temperature water bath at 75°C for 4 hours; after the reaction is completed, it is cooled to room temperature, separated by centrifugation, washed with solvent multiple times, and finally dried in a vacuum drying oven at 65°C for 8 hours.

[0023] Among them, the coupling agent can be a silane coupling agent (preferably, silane coupling agent KH-560), a titanate coupling agent, etc., and the amount of silane coupling agent KH-560 is 3-8% of the mass of the functional powder; the solvent can be anhydrous ethanol, propanol and other commonly used organic solvents, and the amount is 5-10 times the mass of the functional powder; the catalyst can be dibutyltin dilaurate, and the amount is 1% of the mass of the silane coupling agent.

[0024] That is, coupling agents are used to modify and disperse functional powders. Taking silane coupling agents as an example, one end of the coupling agent can react chemically with hydroxyl groups on the powder surface (hydroxyl groups may exist on the surface of bismuth oxide and lanthanum oxide) to form a chemical bond; the other end can react with active groups in the matrix material. The coupling agent establishes a "bridge" between the powder and the matrix, not only improving the dispersion of the powder in the matrix but also strengthening the bonding between the powder and the matrix. The presence of the coupling agent can also change the surface energy of the powder particles, reducing the tendency of the particles to agglomerate. For example, a titanate coupling agent can change the surface of the powder from hydrophilic to lipophilic, greatly improving the dispersibility of the powder when used in an oily system.

[0025] In addition, the present invention also provides a surfactant modification method, which is as follows:

[0026] A surfactant is added to a solvent and heated to completely dissolve it. The functional powder is then added and ultrasonically dispersed for 15-30 minutes. The mixture is then stirred in a constant temperature water bath at 40-70°C at a speed of 150-300 r / min for reaction for 1-2 hours. After the reaction is completed, the mixture is cooled to room temperature, centrifuged, washed multiple times with a solvent, and dried in a vacuum drying oven at 50-80°C for 3-8 hours. The surfactant may be selected from stearic acid, sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether, etc., with the amount thereof being 3-8% of the mass of the functional powder. The solvent may be selected from commonly used organic solvents such as anhydrous ethanol and propanol, with the amount thereof being 5-10 times the mass of the functional powder.

[0027] In addition, the present invention also provides a polymer coating modification method, which is as follows:

[0028] The polymer is added to deionized water, heated until completely dissolved, cooled to 50-80°C, functional powder is added, ultrasonic dispersion is carried out for 10-30 minutes, and then stirred in a constant temperature water bath at 50-80°C at a speed of 200-500r / min for 2-4 hours. After the reaction is completed, separation is carried out by filtration, washing with deionized water multiple times, and drying in a vacuum drying oven at 50-80°C for 5-10 hours.

[0029] The polymer can be polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethylene imine, polyacrylamide, etc., and its dosage is 5-10% of the mass of the functional powder; deionized water is used as a solvent, and its dosage is 10-15 times the mass of the functional powder.

[0030] The present invention also provides a protective product, which includes the above-mentioned protective material; more specifically, the protective product can be protective equipment related to head protection, respiratory protection, eye protection, face protection, hearing protection, hand protection, foot protection and body protection, such as protective clothing, protective gloves, protective hats, etc.

[0031] The technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0032] The protective material prepared by the present invention has good fluidity, high stability, and adjustable density, and can provide good shielding performance in all energy regions; and the casting and molding is rapid, reliable, flexible and changeable, and can be injection-molded into sheets and blocks for stacking and use, or can be directly cast and applied to the interior of various complex protective devices, which is conducive to practical engineering applications, has low cost, and has strong commercial value. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0034] Example 1

[0035] A low-cost X-ray shielding material, comprising the following components by weight: 40 parts of modified silicone resin, 55 parts of functional powder, and 0.06 parts of Custer platinum catalyst.

[0036] The modified silicone resin includes boron-containing silicone resin and hydrogen-containing silicone resin, wherein the hydrogen-containing silicone resin is DY-V411 vinyl silicone oil; the boron-containing silicone resin is a silicone resin with boron elements introduced into the siloxane main chain, and the preparation method thereof is as follows: using methylboric acid as a boron source and trifluoromethanesulfonic acid as a catalyst, adding methyldichlorosilane in an anhydrous ethanol solvent system and reacting for 1 hour to obtain the boron-containing silicone resin; the mass ratio of methylboric acid, trifluoromethanesulfonic acid and methyldichlorosilane is 5:1:4;

[0037] The functional powder includes bismuth oxide, barium oxide, lanthanum oxide, gadolinium oxide, tantalum oxide and tungsten powder in equal proportions.

[0038] A method for preparing a low-cost X-ray shielding material comprises the following steps:

[0039] S1. The modified silicone resin was subjected to high-temperature molecular distillation and devolatilization at 150°C, added to the reactor, and thoroughly mixed and sheared to obtain a uniform and stable high-temperature resistant matrix material;

[0040] S2. First, dibutyltin dilaurate was added to anhydrous ethanol and stirred evenly, and then a silane coupling agent KH-560 was added. The mixture was stirred at room temperature of 25°C for 30 minutes for hydrolysis activation. The functional powder was then added to anhydrous ethanol and ultrasonically dispersed for 20 minutes. The mass of dibutyltin dilaurate was 8 times the mass of the functional powder. The hydrolyzed silane coupling agent solution was then slowly added to the dispersed bismuth oxide powder ethanol suspension. The mixture was stirred in a constant temperature water bath at 75°C at a speed of 300 r / min for 4 hours. After the reaction was completed, the mixture was cooled to room temperature, separated by centrifugation, washed with anhydrous ethanol several times, and finally dried in a vacuum drying oven at 65°C for 8 hours to obtain a modified functional powder.

[0041] S3. The base material obtained in S1, the modified functional powder obtained in S2 and the catalyst are uniformly mixed, and then deaerated and cast to obtain the protective material.

[0042] Example 2

[0043] A low-cost X-ray shielding material, comprising the following components by weight: 50 parts of modified silicone resin, 60 parts of functional powder, and 0.05 parts of Custer platinum catalyst.

[0044] The modified silicone resin is a silicone resin with a low rigid group content. Its preparation method is as follows: using phenylsiloxane as a benzene source, methyltrimethoxysilane and dimethyldimethoxysilane are added in the presence of anhydrous ethanol solvent and concentrated sulfuric acid as a catalyst, and subjected to a hydrolysis polymerization reaction for 1 hour to obtain a silicone resin with a low phenyl content. The mass ratio of phenylsiloxane, concentrated sulfuric acid, methyltrimethoxysilane, and dimethyldimethoxysilane is 2:1:8:8;

[0045] The functional powder includes bismuth oxide, barium oxide, lanthanum oxide, gadolinium oxide, tantalum oxide and tungsten powder in equal proportions.

[0046] A method for preparing a low-cost X-ray shielding material comprises the following steps:

[0047] S1. The modified silicone resin was subjected to high-temperature molecular distillation and devolatilization at 150°C, added to the reactor, and thoroughly mixed and sheared to obtain a uniform and stable high-temperature resistant matrix material;

[0048] S2. First, stearic acid was added to anhydrous ethanol and heated to 50°C to completely dissolve it. The functional powder was then added, wherein the mass of stearic acid was 5% of the mass of the functional powder. After ultrasonic dispersion for 15 minutes, the mixture was stirred in a constant temperature water bath at 50°C at a speed of 200 r / min for 2 hours. After the reaction was completed, the mixture was cooled to room temperature, separated by centrifugation, washed three times with anhydrous ethanol, and dried in a vacuum drying oven at 60°C for 5 hours to obtain the modified functional powder.

[0049] S3. The base material obtained in S1, the modified functional powder obtained in S2 and the catalyst are uniformly mixed, and then deaerated and cast to obtain the protective material.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that: a low-cost X-ray shielding material, calculated by weight, includes the following components: 30 parts of modified silicone resin, 70 parts of functional powder, and 0.03 parts of Custer platinum catalyst.

[0052] In a method for preparing a low-cost X-ray shielding material, step S2 adopts the following method: PVA is added to 10 times the mass of deionized water, wherein the mass of PVA is 1.5 times the mass of the functional powder, heated to 90°C and stirred to dissolve, cooled to 60°C after complete dissolution, the above-mentioned functional powder is added, ultrasonically dispersed for 20 minutes, and then stirred in a constant temperature water bath at 60°C at a speed of 300 r / min for 3 hours; after the reaction is completed, separated by filtration, washed with deionized water 3 times, and dried in a vacuum drying oven at 70°C for 7 hours to obtain a modified functional powder.

[0053] Comparative Example 1

[0054] The difference between this comparative example and Example 1 is that the silicone resin in the protective material is methyldichlorosilane, that is, no modification treatment is performed.

[0055] Comparative Example 2

[0056] The difference between this comparative example and Example 1 is that the method for preparing the protective material does not contain step S2, that is, the functional powder is not modified.

[0057] Experimental Example 1

[0058] The protective materials obtained in each embodiment and comparative example were subjected to X-ray shielding performance tests, each of which was tested three times and the average value was taken. The test results are shown in Table 1.

[0059] Test method: In accordance with GBZ / T 147-2002 "Determination of attenuation properties of X-ray protective materials", the operation is as follows: Place the detector 3.0mm away from the X-ray (120kV), and the rays are incident from a direction perpendicular to the detector surface. Measure the dose rate without sample and after the protective material samples obtained from various embodiments and comparative examples. Calculate the lead equivalent of the sample based on the shielding rate of the standard lead sheet.

[0060] Table 1 - X-ray shielding test results

[0061]

[0062]

[0063] It can be seen from the data in Table 1 that the protective material prepared by the present invention has excellent radiation protection performance and can meet the irradiation performance requirements of X-rays. In addition, the cost of the matrix material and functional particle material used is relatively low, the manufacturing cost is low, and it has good development potential and commercial value.

[0064] However, since the base material of the protective material of Comparative Example 1 has not been modified, the bonding force between the functional material and the base material is poor and unstable, resulting in poor shielding performance.

[0065] In Comparative Example 2, since the functional powder has not been modified, the overall compatibility of the functional powder is poor, the dispersion is uneven, the dispersion in the matrix material is poor and the bonding force is poor, which greatly affects the functional powder from exerting its due shielding performance. The shielding effect and density in different energy zones need to be limited, especially the supplementary absorption in the low energy zone. Therefore, in the test of X-ray shielding performance, the effect is poor.

[0066] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A low-cost X-ray shielding material, characterized in that: The composition includes the following components by weight: 15-60 parts of modified silicone resin, 40-80 parts of functional powder, and 0.01-1 parts of Custer platinum catalyst; The modified silicone resin is one or more of boron-containing silicone resin, silicone resin with low rigid group content or hydrogen-containing silicone resin; The functional powder includes one or more of bismuth, barium, lanthanum, gadolinium, tantalum, tungsten and compounds thereof.

2. The low-cost X-ray shielding material according to claim 1, characterized in that: The boron-containing silicone resin is a silicone resin in which a boron element is introduced into the silicon-oxygen main chain. The preparation method thereof is as follows: using methylboric acid or phenylboric acid as a boron source and an acid as a catalyst, silane is added in a solvent system and reacted for a period of time to obtain the boron-containing silicone resin; wherein the mass ratio of the boron source, catalyst, and silane is 3-10:1:1-5.

3. The low-cost X-ray shielding material according to claim 1, characterized in that: The silicone resin with low rigid group content is a silicone resin with a low molar content of rigid groups introduced into the side chain. The preparation method thereof is as follows: phenylsiloxane or phenylchlorosilane is used as a benzene source, an acid is used as a catalyst, methyltrimethoxysilane and dimethyldimethoxysilane are added to a solvent system, and after hydrolysis and polymerization reaction, a silicone resin with low phenyl content is obtained; wherein the mass ratio of the benzene source, the catalyst, the methyltrimethoxysilane, and the dimethyldimethoxysilane is 1-3:1:5-10:5-10.

4. The low-cost X-ray shielding material according to claim 1, characterized in that: The hydrogen-containing silicone resin is a low-molecular-weight methyl vinyl silicone resin containing branched vinyl groups or a branched hydrogen-containing silicone resin.

5. A method for preparing a low-cost X-ray shielding material according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. After the modified silicone resin is subjected to high-temperature molecular distillation and devolatilization, it is added to the reactor and thoroughly mixed and sheared to obtain a uniform and stable matrix material; S2. The modifier is mixed with the functional powder, and after a period of reaction, the modifier is coated on the surface of the functional powder to obtain a modified functional powder; S3. After uniformly mixing the base material obtained in S1, the modified functional powder obtained in S2 and the Custer platinum catalyst, degassing and pouring are performed to obtain a protective material.

6. The method for preparing a low-cost X-ray shielding material according to claim 5, characterized in that: In S2, the modifier is a coupling agent, a surfactant or a polymer.

7. The method for preparing a low-cost X-ray shielding material according to claim 6, characterized in that: The modifier is a coupling agent, and the preparation method of the modified functional powder is: First, dibutyltin dilaurate is added to a solvent and stirred evenly, and then a coupling agent is added and stirred at room temperature for hydrolysis activation to obtain a hydrolysis coupling agent solution; Then, the functional powder is added to the solvent and ultrasonically dispersed for a period of time to obtain a functional powder suspension; Subsequently, the hydrolysis coupling agent solution is slowly added to the dispersed functional powder suspension, and stirred in a constant temperature water bath to react for a period of time; After the reaction is completed, the mixture is cooled to room temperature, centrifuged, washed, and dried; wherein the coupling agent is a silane coupling agent or a titanate coupling agent, and the amount of the coupling agent is 3-8wt% of the mass of the functional powder; the solvent is anhydrous ethanol or propanol, and the volume amount thereof is 5-10 times the mass of the functional powder; the amount of dibutyltin dilaurate is 1-5wt% of the mass of the coupling agent.

8. The method for preparing a low-cost X-ray shielding material according to claim 6, characterized in that: The modifier is a surfactant, and the preparation method of the modified functional powder is as follows: adding the surfactant to a solvent, heating it to completely dissolve it, then adding the functional powder, ultrasonicating it for a period of time, and stirring and reacting it in a constant temperature water bath for a period of time; after the reaction, cooling it to room temperature, centrifuging it, washing it, and drying it; wherein the surfactant is stearic acid, sodium dodecylbenzenesulfonate, and polyoxyethylene alkyl ether, and the amount thereof is 3-8wt% of the mass of the functional powder; the solvent is anhydrous ethanol or propanol, and the volume amount thereof is 5-10 times the mass of the functional powder.

9. The method for preparing a low-cost X-ray shielding material according to claim 6, characterized in that: The modifier is a polymer, and the preparation method of the modified functional powder is as follows: adding the polymer to deionized water, heating until completely dissolved, cooling, adding the functional powder, ultrasonically dispersing for a period of time, and then stirring and reacting in a constant temperature water bath for a period of time; after the reaction is completed, cooling to room temperature, centrifugation, washing, and drying; wherein the polymer is polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol, polyethylene imine, or polyacrylamide, and the amount thereof is 5-10wt% of the mass of the functional powder.

10. A protective product, characterized in that: The protective article comprises the protective material according to any one of claims 1 to 4.

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