Infusible shielding material and method of making same

Abstract

The application discloses a pourable shielding material and a preparation method thereof. The material comprises 80-100 parts by weight of an epoxy resin, 10-40 parts by weight of a curing agent, 1-20 parts by weight of a shielding auxiliary agent and 1-80 parts by weight of a filler, wherein the filler comprises magnesium hydroxide and aluminum hydroxide, and the epoxy resin comprises at least one of bisphenol A epoxy resin and bisphenol F epoxy resin. The pourable shielding material has excellent shielding effect, fluidity and low volume shrinkage, specifically, the viscosity of the material is 4000-6000 mPa.s, and the volume shrinkage is not more than 1%. The material can fully fill the gap between the main body, and no new structural gap is generated after curing, and is especially suitable for shielding structures of special-shaped regions or irregular regions, effectively improving the reliability and safety of the shielding structure, and cooperating with the main body shielding material, significantly improving the installation efficiency of the shielding body.

Description

Technical Field

[0001] The present invention belongs to the technical field of shielding materials, and in particular relates to a pourable shielding material and a preparation method thereof. Background Art

[0002] In the shielding design of nuclear technology devices, polyethylene, boron-containing polyethylene, or lead-boron polyethylene components are generally used as the primary shielding material. Gaps between the shielding materials are filled with shielding putty or connected through multiple curved splices to minimize their adverse effects on the shield. The shielding materials are machined together through the splices, which ensures high machining and installation precision. However, during actual installation, due to large dimensional errors in the surrounding steel structure, the gaps at the splice joints can exceed the designed values, necessitating the use of shielding putty. However, shielding putty is highly viscous and generally requires manual filling along the gaps, which reduces application efficiency and cannot guarantee that the putty will fill all gaps.

[0003] Traditional rigid shielding materials like polyethylene, boron-containing polyethylene, or lead-boron polyethylene are difficult to precisely machine and install in irregular shielding areas. Shielding putty is also difficult to apply, resulting in numerous structural gaps during installation. The traditional combination of rigid shielding materials and shielding putty is inefficient and incapable of fully filling any structural gaps. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, one purpose of the present invention is to propose a pourable shielding material and a preparation method thereof. The pourable shielding material has excellent shielding effect, fluidity and low volume shrinkage. Specifically, the viscosity of the material is 4000mPa·s~6000mPa·s, and the volume shrinkage is not more than 1%. The material can fully fill the gaps between the main bodies and will not produce new structural gaps after curing. It is particularly suitable for shielding structures in special-shaped areas or irregular areas, effectively improving the reliability and safety of the shielding structure, and in combination with the main body shielding material, significantly improving the installation efficiency of the shielding body.

[0005] In one aspect, the present invention provides a pourable shielding material. According to an embodiment of the present invention, the pourable shielding material includes: 80 to 100 parts by weight of an epoxy resin, 10 to 40 parts by weight of a curing agent, 1 to 20 parts by weight of a shielding aid, and 1 to 80 parts by weight of a filler, wherein the filler includes magnesium hydroxide and aluminum hydroxide, and the epoxy resin includes at least one of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0006] The pourable shielding material according to the above-mentioned embodiments of the present application comprises 80-100 parts by weight of epoxy resin, 10-40 parts by weight of curing agent, 1-20 parts by weight of shielding aid and 1-80 parts by weight of filler. On the one hand, the epoxy resin reacts with the curing agent to make the material have certain mechanical properties, and based on 80-100 parts by weight of epoxy resin, if the curing agent is added too little, the material is not completely cured, resulting in tackiness on the surface of the material, and if the curing agent is added too much, the mechanical properties such as tensile strength of the material are reduced. The shielding aid is added in an appropriate amount to make the material have shielding performance meeting the requirements, and the shielding aid has an influence on the viscosity and flowability of the material, specifically, if the shielding aid is added too little, the shielding effect of the material is poor, and if the shielding aid is added too much, the viscosity of the system is too large and the flowability is greatly reduced, causing uneven mixing and affecting the reliability of the shielding effect. The epoxy resin comprises at least one of bisphenol A epoxy resin and bisphenol F epoxy resin, and by selecting the above-mentioned types of epoxy resin, the bisphenol A epoxy resin can give the system good mechanical properties and bonding properties, and the bisphenol F epoxy resin has low viscosity, and if the two types of epoxy resin are used together, an epoxy resin system with good flowability and high mechanical properties can be obtained. The filler comprises magnesium hydroxide and aluminum hydroxide, and by adding the filler, the material can have appropriate viscosity and flowability and reduce the material's volume shrinkage, specifically, the filler and the shielding aid cooperate with each other, the filler is distributed in the voids of the shielding aid, which can effectively reduce the volume shrinkage of the material, and at the same time, the interface action between the filler and the resin system is good, which is also conducive to reducing the viscosity of the material and improving the flowability, specifically, if the filler is added too much, the viscosity of the system increases and the flowability decreases, and if the filler is added too little, the interaction points between the filler and the resin system are too few, which cannot increase the flowability and reduce the volume shrinkage of the material, and at the same time, by controlling the amount of the filler within the above-mentioned range, the content of hydrogen elements in the shielding material can be increased, thereby further improving the ability of the material to shield neutrons. Thus, the pourable shielding material has excellent shielding effect, flowability and low volume shrinkage, specifically, the viscosity of the material is 4000 mPa·s-6000 mPa·s and the volume shrinkage is not greater than 1%, the material can fully fill the gaps between the main bodies, and after curing, new structural gaps will not be generated, which is especially suitable for shielding structures in irregular or irregular areas, effectively improving the reliability and safety of the shielding structure, and cooperating with the main shielding material, the installation efficiency of the shielding body is significantly improved.

[0007] In addition, the pourable shielding material according to the above-mentioned embodiments of the present application can also have the following technical features:

[0008] In some embodiments of the present application, the particle size of the filler is 1-50 μm. Thus, the flowability of the material can be optimized and the volume shrinkage of the material can be reduced.

[0009] In some embodiments of the present invention, the particle size of the shielding aid is 50 nm to 50 μm, thereby optimizing the fluidity of the material, improving the shielding performance of the material, and reducing the volume shrinkage of the material.

[0010] In some embodiments of the present invention, the curing temperature of the pourable shielding material is 15° C. to 30° C., and the curing time is 12 hours to 24 hours.

[0011] In some embodiments of the present invention, the shielding aid comprises at least one of boron carbide, boron powder, or boron nitride, thereby improving the shielding performance of the material.

[0012] In some embodiments of the present invention, the curing agent includes a modified aliphatic curing agent, and the modified aliphatic curing agent includes at least one of a 593 curing agent, a T31 curing agent, and a 7220 curing agent.

[0013] In some embodiments of the present invention, based on 80 to 100 parts by weight of the epoxy resin, the invention further comprises: at least one of 0 to 20 parts by weight of an active epoxy resin diluent, 0.1 to 1 part by weight of a defoaming agent, and 1 to 2 parts by weight of a dispersant.

[0014] In a second aspect of the present invention, a method for preparing the above-mentioned pourable shielding material is provided. According to an embodiment of the present invention, the method comprises:

[0015] The epoxy resin, shielding aid, filler and curing agent are mixed and stirred to obtain a pourable shielding material.

[0016] Therefore, the method can be used to prepare a pourable shielding material with excellent shielding effect, fluidity and low volume shrinkage.

[0017] In addition, the method for preparing a pourable shielding material according to the above embodiment of the present invention may also have the following technical features:

[0018] In some embodiments of the present invention, the method includes: mixing and stirring the epoxy resin, the shielding aid, and the filler to obtain component A; and mixing and stirring component A with the curing agent to obtain a pourable shielding material. Thus, the components can be evenly mixed to obtain a pourable shielding material with excellent uniformity.

[0019] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments with reference to the following drawings, in which:

[0021] Figure 1 is a cross-sectional view of the pourable shielding material after curing according to Example 1 of the present invention;

[0022] Figure 2 is a cross-sectional view of the pourable shielding material after curing according to Example 1 of the present invention;

[0023] Figure 3 is a cross-sectional view of the pourable shielding material after curing according to Comparative Example 1 of the present invention;

[0024] Figure 4 This is a top surface view of the pourable shielding material after curing in Comparative Example 3 of the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, which are intended to explain the present invention but are not to be construed as limiting the present invention.

[0026] In one aspect, the present invention provides a pourable shielding material. According to an embodiment of the present invention, the pourable shielding material includes: 80 to 100 parts by weight of an epoxy resin, 10 to 40 parts by weight of a curing agent, 1 to 20 parts by weight of a shielding aid, and 1 to 80 parts by weight of a filler, wherein the filler includes magnesium hydroxide and aluminum hydroxide, and the epoxy resin includes at least one of a bisphenol A epoxy resin and a bisphenol F epoxy resin.

[0027] The pourable shielding material according to the above embodiment of the present application comprises 80-100 parts by weight of epoxy resin, 10-40 parts by weight of curing agent, 1-20 parts by weight of shielding aid and 1-80 parts by weight of filler. The inventor finds that, on the one hand, the epoxy resin reacts with the curing agent to make the material have certain mechanical properties, and based on 80-100 parts by weight of epoxy resin, if the curing agent is added too little, the material does not fully cure, resulting in tackiness on the surface of the material, and the viscosity of the material is too large, and if the curing agent is added too much, the mechanical properties such as tensile strength of the material decrease. The shielding aid is added in an appropriate amount to make the material have shielding performance meeting the requirements, and the shielding aid has an influence on the viscosity and flowability of the material, specifically, if the shielding aid is added too little, the shielding effect of the material is poor, and if the shielding aid is added too much, the viscosity of the system is too large, the flowability is greatly reduced, causing uneven mixing and affecting the reliability of the shielding effect. The epoxy resin comprises at least one of bisphenol A epoxy resin and bisphenol F epoxy resin, by selecting the above types of epoxy resin, the bisphenol A epoxy resin can give the system good mechanical properties and bonding properties, the bisphenol F epoxy resin has relatively low viscosity, and if the two types of epoxy resin are used together, an epoxy resin system with good flowability and high mechanical properties can be obtained. The filler comprises magnesium hydroxide and aluminum hydroxide, by adding the filler, the material can have appropriate viscosity and flowability and reduce the material curing volume shrinkage, in particular, the filler and the shielding aid cooperate with each other, the filler is distributed in the voids of the shielding aid, which can effectively reduce the volume shrinkage of the material, and at the same time, the interface action between the filler and the resin system is good, which is also beneficial to reducing the viscosity of the material and improving the flowability, specifically, if the filler is added too much, the viscosity of the system increases and the flowability decreases, and if the filler is added too little, the interaction points between the filler and the resin system are too few, which cannot increase the flowability and reduce the volume shrinkage of the material, and at the same time, by controlling the amount of the filler within the above range, the content of hydrogen elements in the shielding material can be increased, thereby further improving the neutron shielding capacity of the material.

[0028] According to the embodiment of the present application, the curing temperature of the above pourable shielding material is 15-30°C, and the curing time is 12-24 hours. The curing speed of the material of the present application is moderate when the curing temperature is between 15-30°C, which can meet the normal construction and use requirements, when the temperature is lower than 15°C, the curing speed significantly decreases, and even the material does not cure, and when the temperature is higher than 30°C, the curing speed is too fast, and if the construction is not properly handled, the material may explode. Therefore, it is shown that the material can be effectively cured at room temperature, and the curing time is appropriate, and the material can be widely used for filling the gaps of various shielding bodies.

[0029] According to an embodiment of the present invention, the curing agent includes a modified aliphatic curing agent, and the modified aliphatic amine curing agent is usually reacted by aliphatic amine and epoxy resin, acrylate or polyisocyanate to reduce the volatility and toxicity of the aliphatic amine, improve the performance of the cured product, and reduce the impact of the environment (such as temperature, air humidity) on the performance of the cured product. Therefore, the present application preferably uses a modified aliphatic curing agent to improve the stability of the material. Further, the modified aliphatic curing agent includes but is not limited to at least one of 593 curing agent, T31 curing agent and 7220 curing agent. It should be noted that in order to improve the fluidity and good curing properties of the material, it is preferred that two or more modified aliphatic curing agents be mixed and used. Those skilled in the art can select the specific type and mixing type according to actual conditions, which will not be repeated here.

[0030] According to an embodiment of the present invention, the particle size of the filler is 1μm to 50μm. The inventors have found that by controlling the particle size of the filler within the above range, it is easy to disperse in the resin system, making the dispersed system more stable, and at the same time maintaining an appropriate viscosity of the dispersed resin system, which can effectively optimize the fluidity of the material and avoid precipitation or stratification. In addition, the volume shrinkage rate of the resin after curing can be reduced from 4% to 5% to below 1%. Therefore, the present application uses fillers with a particle size of 1μm to 50μm, which can optimize the fluidity of the material and reduce the volume shrinkage rate of the material.

[0031] According to an embodiment of the present invention, the particle size of the shielding aid is 50nm to 50μm. The inventors found that controlling the particle size of the shielding aid within the above range can not only improve the dispersibility of the resin system and optimize the fluidity of the material, but also ensure the shielding performance of the material with a smaller amount of shielding aid added, increase the hydrogen content of the material, thereby improving the shielding performance of the material, and the shielding aid and filler particle size distribution match, which can further reduce the volume shrinkage of the material during the resin curing process. Therefore, the shielding aid with a particle size of 50nm to 50μm used in this application can optimize the fluidity of the material, improve the shielding performance of the material, and reduce the volume shrinkage of the material. Furthermore, the shielding aid includes at least one of boron carbide, boron powder or boron nitride. The above-mentioned shielding aid has a very high thermal neutron absorption capacity and can absorb thermal neutrons after moderation. Therefore, the use of the above-mentioned shielding aid can improve the shielding performance of the material.

[0032] According to an embodiment of the present invention, based on 80 to 100 parts by weight of the epoxy resin, the composition further comprises: at least one of 0 to 20 parts by weight of an active epoxy resin diluent, 0.1 to 1 part by weight of a defoaming agent, and 1 to 2 parts by weight of a dispersant. The inventors have found that the active epoxy resin diluent can reduce the viscosity of the resin and increase the fluidity of the material, the defoaming agent can eliminate and prevent the generation of foam, which helps the reaction process to proceed smoothly and ensure the quality of the material, and the dispersant can make the components more evenly dispersed in the material system, thereby improving the quality of the material. It should be noted that the active epoxy resin diluent, defoaming agent, and dispersant are conventional materials in the art, and those skilled in the art can select them according to actual conditions. For example, the active epoxy resin diluent includes a bifunctional active diluent, and the active epoxy resin diluent includes but is not limited to alkyl glycidyl ether, alkylene glycidyl ether, or fatty glycidyl ether, etc., the defoaming agent includes but is not limited to polyether defoaming agent, silicone defoaming agent, etc., and the dispersant includes but is not limited to polyamide, polyacrylate salt, etc.

[0033] Therefore, the pourable shielding material has excellent shielding effect, fluidity and low volume shrinkage. Specifically, the viscosity of the material is 4000mPa·s~6000mPa·s, and the volume shrinkage is not more than 1%. The material can fully fill the gaps between the main bodies and will not produce new structural gaps after curing. It is particularly suitable for shielding structures in special-shaped or irregular areas, effectively improving the reliability and safety of the shielding structure, and in combination with the main body shielding material, significantly improving the installation efficiency of the shielding body.

[0034] In a second aspect of the present invention, a method for preparing the above-mentioned pourable shielding material is provided. According to an embodiment of the present invention, the method comprises:

[0035] The epoxy resin, shielding aid, filler and curing agent are mixed and stirred to obtain a pourable shielding material.

[0036] The epoxy resin reacts with the curing agent to impart certain mechanical properties to the material, while the shielding agent imparts shielding properties. The filler and other components (shielding agent, curing agent) work synergistically to significantly optimize the material's fluidity, reduce its volume shrinkage, and enhance its shielding effectiveness. This method can produce a pourable shielding material with excellent shielding effectiveness, fluidity, and low volume shrinkage.

[0037] According to an embodiment of the present invention, the method includes: mixing the epoxy resin, the shielding agent, and the filler to obtain component A; and mixing component A with the curing agent to obtain a pourable shielding material. By first uniformly mixing the other components, except the curing agent, before reacting with the curing agent, the uniformity of the components in the material system and the completeness of the reaction can be improved, thereby further enhancing the overall performance of the material. It should be noted that when more than one curing agent is used, the various curing agents should be uniformly mixed before reacting with component A. Specifically, the multiple curing agents are mixed in proportion, vacuumed, and stirred at room temperature at a speed of 100 to 500 rpm for 10 to 30 minutes to ensure thorough mixing of the curing agents. Those skilled in the art will appreciate that component A may also include at least one of an active epoxy resin diluent, a defoamer, and a dispersant. Therefore, at least one of the active epoxy resin diluent, defoamer, and dispersant can be mixed with the epoxy resin, shielding agent, and filler before being mixed with the curing agent.

[0038] According to an embodiment of the present invention, the epoxy resin, shielding aid, and filler are stirred and mixed, and a vacuum may be applied. The stirring speed is 100 to 1500 r / min at room temperature, and the stirring time is 30 to 60 minutes to ensure that the components are fully mixed. Furthermore, the mixed components are mixed with a curing agent, and the stirring speed is 200 to 500 r / min at room temperature, and the stirring time is 10 to 30 minutes to ensure that the curing agent is fully mixed to form a pourable shielding material.

[0039] The present invention is described below with reference to specific examples. It should be noted that these examples are merely illustrative and do not limit the present invention in any way.

[0040] Example 1

[0041] The pourable shielding material includes the following components: 50 parts by weight of bisphenol A epoxy resin, 50 parts by weight of bisphenol F epoxy resin, 30 parts by weight of aliphatic curing agent (7220 curing agent), 2 parts by weight of 10μm boron carbide powder, 50 parts by weight of 50μm aluminum hydroxide, 0.5 parts by weight of defoaming agent (polyether defoaming agent), and 2 parts by weight of wetting and dispersing agent (polyamide).

[0042] The preparation method comprises the following steps:

[0043] 1) bisphenol A resin, bisphenol F resin, boron carbide powder, aluminum hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 800 r / min for 90 min;

[0044] 2) Mix the various curing agents and stir mechanically at 200 r / min for 30 min;

[0045] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 250 r / min for 15 minutes to prepare a pourable shielding material.

[0046] 4) When in use, manually pour the shielding space with a height of 1.2m and a gap width of 2 to 4mm. The pouring can be done in two times, with each pouring height of about 600mm.

[0047] refer to Figure 1 and Figure 2 The pourable shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and not layered. Figure 2 It can be seen that when the cross section is cut open, the top and bottom are uniform and the color is consistent.

[0048] Example 2

[0049] The pourable shielding material includes the following components: 50 parts by weight of bisphenol A epoxy resin, 30 parts by weight of bisphenol F epoxy resin, 20 parts by weight of active epoxy resin diluent (D732), 35 parts by weight of aliphatic curing agent (same as Example 1), 5 parts by weight of 1 μm boron carbide powder, 30 parts by weight of 5 μm aluminum hydroxide, 0.5 parts by weight of defoaming agent (same as Example 1), and 1 part by weight of wetting and dispersing agent (same as Example 1).

[0050] The preparation method comprises the following steps:

[0051] 1) bisphenol A resin, bisphenol F resin, boron carbide powder, aluminum hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 1200 r / min for 60 min;

[0052] 2) Mix the various curing agents and stir mechanically at 500 r / min for 15 minutes;

[0053] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 500 r / min for 10 minutes to prepare a pourable shielding material.

[0054] 4) When in use, manually pour the shielding space with a height of 1.2m and a gap width of 2 to 4mm. The pouring can be done in two times, with each pouring height of about 600mm.

[0055] The perfusible shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and non-stratified.

[0056] Example 3

[0057] The pourable shielding material includes the following components: 90 parts by weight of bisphenol F epoxy resin, 10 parts by weight of active epoxy resin diluent (same as Example 2), aliphatic curing agent (25 parts by weight of 7220 curing agent, 5 parts by weight of 593 curing agent), 1 part by weight of 50nm boron carbide powder, 20 parts by weight of 1μm aluminum hydroxide, 0.5 parts by weight of defoaming agent (same as Example 1), and 1.5 parts by weight of wetting and dispersing agent (same as Example 1).

[0058] The preparation method comprises the following steps:

[0059] 1) Mix bisphenol A resin, bisphenol F resin, boron carbide powder, aluminum hydroxide, defoamer and wetting dispersant, and stir mechanically at 1500 r / min for 50 min;

[0060] 2) Mix the various curing agents and stir mechanically at 300 r / min for 30 min;

[0061] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 300 r / min for 20 minutes to prepare a pourable shielding material.

[0062] 4) When in use, the shielding space with a height of 0.8m and a gap width of 2 to 4mm can be manually poured in place at one time.

[0063] The perfusible shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and non-stratified.

[0064] Example 4

[0065] The pourable shielding material includes the following components: 60 parts by weight of bisphenol A epoxy resin, 30 parts by weight of bisphenol F epoxy resin, 10 parts by weight of active epoxy resin diluent (same as Example 2), 32 parts by weight of aliphatic curing agent (same as Example 1), 2 parts by weight of 100nm boron nitride powder, 70 parts by weight of magnesium hydroxide with a particle size of 45μm, 0.6 parts by weight of defoaming agent (same as Example 1), and 1.5 parts by weight of wetting and dispersing agent (same as Example 1).

[0066] The preparation method comprises the following steps:

[0067] 1) bisphenol A resin, bisphenol F resin, boron nitride powder, magnesium hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 1500 r / min for 60 min;

[0068] 2) Mix the various curing agents and stir mechanically at 400 rpm for 15 minutes;

[0069] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 500 r / min for 20 minutes to prepare a pourable shielding material.

[0070] The perfusible shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and non-stratified.

[0071] Example 5

[0072] The pourable shielding material includes the following components: 50 parts by weight of bisphenol A epoxy resin, 40 parts by weight of bisphenol F epoxy resin, 10 parts by weight of active epoxy resin diluent (same as Example 2), 10 parts by weight of aliphatic curing agent (same as Example 1), 10 parts by weight of 30 μm boron carbide powder, 80 parts by weight of magnesium hydroxide with a particle size of 30 μm, 0.5 parts by weight of defoaming agent (same as Example 1), and 2 parts by weight of wetting and dispersing agent (same as Example 1).

[0073] The preparation method comprises the following steps:

[0074] 1) bisphenol A resin, bisphenol F resin, boron carbide powder, magnesium hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 1500 r / min for 50 min;

[0075] 2) Mix the various curing agents and stir mechanically at 400 rpm for 12 minutes;

[0076] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 500 r / min for 20 minutes to prepare a pourable shielding material.

[0077] The perfusible shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and non-stratified.

[0078] Example 6

[0079] The pourable shielding material includes the following components: 50 parts by weight of bisphenol A epoxy resin, 50 parts by weight of bisphenol F epoxy resin, 40 parts by weight of aliphatic curing agent (same as Example 1), 20 parts by weight of 50 μm boron powder, 1 part by weight of magnesium hydroxide with a particle size of 1 μm, 0.5 parts by weight of defoaming agent (same as Example 1), and 1.5 parts by weight of wetting and dispersing agent (same as Example 1).

[0080] The preparation method comprises the following steps:

[0081] 1) bisphenol A resin, bisphenol F resin, boron carbide powder, magnesium hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 1200 r / min for 70 min;

[0082] 2) Mix the various curing agents and stir mechanically at 500 r / min for 15 minutes;

[0083] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 500 r / min for 20 minutes to prepare a pourable shielding material.

[0084] The perfusible shielding material prepared by the above method has good fluidity, and the cross section of the material after solidification is uniform and non-stratified.

[0085] Comparative Example 1

[0086] The difference between the pourable shielding material components of Comparative Example 1 and Example 1 is that there is no aluminum hydroxide in Comparative Example 1.

[0087] The preparation method of Comparative Example 1 is the same as that of Example 1.

[0088] The cross-sectional view of the cured pourable shielding material prepared in Comparative Example 1 is as follows: Figure 3 As shown, from Figure 3 It can be seen that when the cross section is cut open, the upper and lower layers have obvious differences in color.

[0089] Comparative Example 2

[0090] The difference between the components of the pourable shielding material of Comparative Example 2 and Example 1 is that in Comparative Example 2, 90 parts by weight of 45 μm aluminum hydroxide are contained.

[0091] The preparation method of Comparative Example 2 is the same as that of Example 1.

[0092] Comparative Example 3

[0093] The pourable shielding material includes the following components: 70 parts by weight of bisphenol A epoxy resin, 20 parts by weight of bisphenol F epoxy resin, 10 parts by weight of active epoxy resin diluent (same as Example 2), 37 parts by weight of aliphatic curing agent (same as Example 1), 2 parts by weight of 100 nm boron powder, 120 parts by weight of magnesium hydroxide with a particle size of 5 μm, 0.5 parts by weight of defoaming agent (same as Example 1), and 5 parts by weight of wetting and dispersing agent (same as Example 1).

[0094] The preparation method comprises the following steps:

[0095] 1) bisphenol A resin, bisphenol F resin, boron carbide powder, magnesium hydroxide, defoaming agent and wetting dispersant were mixed and mechanically stirred at 1000 r / min for 60 min;

[0096] 2) Mix the various curing agents and stir mechanically at 500 r / min for 10 min;

[0097] 3) The materials prepared in step 1) and step 2) were mixed, and mechanically stirred at 500 r / min for 20 minutes to prepare a pourable shielding material.

[0098] The pourable shielding material of Comparative Example 3 has high viscosity and poor fluidity, and the surface of the material after solidification is uneven, such as Figure 4 shown.

[0099] Comparative Example 4

[0100] The difference between the components of the pourable shielding material of Comparative Example 4 and Example 1 is that Comparative Example 4 uses 50 parts by weight of bisphenol F epoxy resin and 50 parts by weight of multifunctional glycidylamine epoxy resin (tetraglycidyldiaminodiphenylmethane epoxy resin).

[0101] The preparation method of Comparative Example 4 is the same as that of Example 1.

[0102] The shielding material of Comparative Example 4 has high viscosity and poor fluidity and cannot be used for filling narrow gaps.

[0103] The specific component weight ratios of the pourable shielding materials of Examples 1-6 and Comparative Examples 1-3 are shown in Table 1.

[0104] Table 1

[0105]

[0106]

[0107] The performance of the shielding materials of Examples 1-6 and Comparative Examples 1-4 was measured using the following method:

[0108] (1) The density of the material is tested in accordance with GB / T1033.1-2008 standard using the immersion method.

[0109] Material density: ρ = m 空 / (m 空 -m 水 )

[0110] Test method:

[0111] Use an analytical balance to measure the mass m of the material in air 空 ;

[0112] Immerse the material completely in water and measure the mass m of the material in water. 水 ;

[0113] Calculate the density of the material according to the formula.

[0114] (2) The volume shrinkage of the material is calculated as follows:

[0115] Curing shrinkage = (1-ρ 前 / ρ 后 )×100%

[0116] Where: 前 : Density before curing, tested by liquid pycnometer method;

[0117] ρ 后 : Density after curing is tested by immersion method.

[0118] Test method:

[0119] Take a 10ml pycnometer, fill it with deionized water, and record the mass m1 at this time;

[0120] After drying and cooling the pycnometer, fill it with the mixed pourable shielding material and record the mass m2 at this time. Then ρ 前 =m2 / m1×ρ 水 (Usually, the density of water is 1.0g / cm 3 calculate);

[0121] The density test method of the pourable shielding material after curing is the same as above;

[0122] Calculate the curing shrinkage of the material according to the above formula.

[0123] (3) The neutron shielding coefficient of the material is determined with reference to the standard CYSXY0009-2022 for the determination of the attenuation performance of neutron ray shielding putty.

[0124] (4) The bonding strength of the material is determined according to the method for determining the tensile shear strength of adhesives in GB / T 7124-2008. For rigid materials, iron sheets are used and the test is conducted after the sample is completely cured for 24 hours.

[0125] (5) The viscosity of the material is tested using a rotary digital viscometer at room temperature, using a 3# rotor and an automatic speed mode.

[0126] The performance measurement results of the shielding materials of Examples 1-6 and Comparative Examples 1-4 are shown in Table 2.

[0127] Table 2

[0128]

[0129]

[0130] From the data in Table 2, it can be seen that the H content of Examples 1-6 is all above 0.90 g / cm 3The neutron shielding coefficients are all no less than 2.2, indicating that the materials of the present application have excellent shielding properties. Comparative Example 1 does not contain fillers. Although the viscosity of the material of Comparative Example 1 is relatively low, the volume shrinkage of the material of Comparative Example 1 is significantly higher than that of the material of the embodiment. The amount of filler added in Comparative Examples 2 and 3 exceeds the scope of this application. Although Comparative Examples 2 and 3 have good volume shrinkage, their viscosity increases significantly, indicating that excessive addition of fillers can significantly reduce the fluidity of the material. Comparative Example 4 changes the type of resin, using a tetrafunctional epoxy resin instead of bisphenol A epoxy resin. As a result, the viscosity of the system increases significantly, the fluidity of the material decreases, and it cannot be used for filling narrow gaps. This is due to the high viscosity of the multifunctional epoxy resin itself. At room temperature, the multifunctional epoxy resin is close to a solid state and lacks fluidity. During use, it is usually necessary to heat the multifunctional epoxy resin to reduce its viscosity, thereby improving its processing performance. In summary, the materials of the present application have suitable fluidity and low volume shrinkage while ensuring good shielding effect.

[0131] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0132] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A pourable shielding material, characterized in that include: 80-100 parts by weight of an epoxy resin, 10-40 parts by weight of a curing agent, 1-20 parts by weight of a shielding aid, 1-80 parts by weight of a filler, 0-20 parts by weight of an active epoxy resin diluent, 0.1-1 parts by weight of a defoamer, and 1-2 parts by weight of a dispersant, wherein the filler comprises magnesium hydroxide and aluminum hydroxide, and the epoxy resin comprises at least one of a bisphenol A epoxy resin and a bisphenol F epoxy resin; The particle size of the filler is 1 μm to 50 μm; The shielding aid comprises at least one of boron carbide, boron powder or boron nitride; The active epoxy resin diluent includes alkyl glycidyl ether or alkylene glycidyl ether; The defoamer includes a polyether defoamer; The dispersant includes polyamide; The particle size of the shielding aid is 50nm~50μm; The curing agent includes a modified aliphatic curing agent, and the modified aliphatic curing agent includes at least one of a 593 curing agent and a 7220 curing agent; The viscosity of the pourable shielding material is 4000mPa·s to 6000mPa·s.

2. A pourable shielding material, characterized in that include: 80-100 parts by weight of an epoxy resin, 10-40 parts by weight of a curing agent, 1-20 parts by weight of a shielding aid, 1-80 parts by weight of a filler, 0-20 parts by weight of an active epoxy resin diluent, 0.1-1 parts by weight of a defoamer, and 1-2 parts by weight of a dispersant, wherein the filler comprises magnesium hydroxide and aluminum hydroxide, and the epoxy resin comprises at least one of a bisphenol A epoxy resin and a bisphenol F epoxy resin; The particle size of the filler is 1 μm to 50 μm; The shielding aid comprises at least one of boron carbide, boron powder or boron nitride; The active epoxy resin diluent includes fatty glycidyl ether; The defoamer includes a polyether defoamer; The dispersant includes polyamide; The particle size of the shielding aid is 50nm~50μm; The curing agent includes a modified aliphatic curing agent, and the modified aliphatic curing agent includes at least one of a 593 curing agent and a 7220 curing agent; The viscosity of the pourable shielding material is 4000mPa·s to 6000mPa·s.

3. The material according to claim 1 or 2, characterized in that The curing temperature of the pourable shielding material is 15° C. to 30° C., and the curing time is 12 hours to 24 hours.

4. A method for preparing the pourable shielding material according to any one of claims 1 to 3, characterized in that: include: Mixing and stirring the epoxy resin, the shielding aid, the filler, the active epoxy resin diluent, the defoamer and the dispersant to obtain component A; The component A and the curing agent are mixed and stirred to obtain the pourable shielding material.

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