Shielding putty material for high-radiation area and preparation method thereof

Abstract

The invention discloses a shielding putty material for a high radiation area and a preparation method thereof, and the material comprises the following components in percentage by weight: 72 wt%-86 wt% of a shielding agent, 1 wt%-3.2 wt% of a curing agent, 3.4 wt%-9.5 wt% of a ternary compound flame retardant, 0.1 wt%-0.15 wt% of a dispersing agent, 0.02 wt%-0.07 wt% of a defoaming agent, 1.8 wt%-3.5 wt% of a liquid flame retardant and the balance of a resin matrix, the resin matrix comprises hydantoin epoxy resin and bisphenol A epoxy resin. The ternary compound flame retardant participates in the curing reaction of the epoxy resin, the liquid flame retardant plays a role in synergistically retarding flame and adjusting the viscosity of the putty, and after the high-filling surface modified shielding agent is added, the shielding putty material has the characteristics of good flame retardance, high adhesion, high temperature resistance, high shielding performance, convenience in construction and the like; and the material has excellent comprehensive performance, and can be widely applied to shielding of equipment, pipelines and radiation hotspots with medium and high radiation levels and filling of gaps and holes of shielding structures.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear radiation protection, and specifically relates to a shielding putty material for high radiation areas and a preparation method thereof. Background Art

[0002] With the rapid development of nuclear power, nuclear energy has been widely used in many fields such as national defense, industry, medical treatment, and shipping, and has become one of the indispensable energy sources. Since α, β, γ, X-rays and neutrons produced by nuclear radiation pose a threat to human health, issues such as nuclear radiation safety, radioactive contamination of nuclear waste and nuclear proliferation have received widespread attention, and the performance requirements for nuclear shielding materials have become increasingly higher.

[0003] For equipment, pipelines and radiation hot spots with medium and high radiation levels, as well as radiation problems in gaps and holes in shielding structures, a material with shielding effect is needed to play a role. It not only plays a repair role, but also needs to have shielding performance equivalent to that of the shielding body material, which can effectively improve the protective performance of the shielding system. This puts higher requirements on shielding putty materials. According to the complexity of the on-site working conditions, the viscosity of the putty needs to be flexibly adjusted, and the shielding putty also needs to maintain good flame retardant properties.

[0004] At present, the existing shielding putty materials mainly include the following: (1) Patent CN113372752A uses epoxy resin as the matrix, aluminum hydroxide as the flame retardant, and alicyclic amine as the curing agent. After adding shielding filler, a high-temperature resistant, high-adhesion, and flame-retardant shielding putty is obtained. However, the flame retardant efficiency of the single-component aluminum hydroxide is low, and there are problems such as a large amount of flame retardant added, a significant increase in the viscosity of the shielding putty, and a limited amount of shielding filler added. It is difficult to meet the requirements of neutron and photon shielding performance in medium and high radiation areas; (2) Patent CN113416443A obtains a shielding putty with adjustable viscosity by adding an active diluent, which has good shielding and bonding strength. However, since the active diluent belongs to an alkyl glycidyl ether, the flame retardancy of the shielding putty cannot be guaranteed; (3) Epoxy resin is selected as the matrix. Considering the cost issue, an additive flame retardant is used for modification. However, the compatibility of the flame retardant with the resin matrix is ​​poor, resulting in a significant decrease in mechanical properties.

[0005] In view of this, it is necessary to develop a shielding putty material and a preparation method thereof which is applied in high radiation areas, is easy to construct, and has excellent comprehensive performance. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a shielding putty material for high radiation areas and a preparation method thereof in view of the above-mentioned deficiencies in the prior art. The ternary composite flame retardant participates in the curing reaction of the epoxy resin, and the liquid flame retardant plays a role of synergistic flame retardancy and adjusting the viscosity of the putty. After adding a high-filling surface-modified shielding agent, the shielding putty material can have the characteristics of good flame retardancy, high adhesion, high temperature resistance, high shielding performance, and convenient construction. It has excellent comprehensive performance and can be widely used in shielding of equipment, pipelines and radiation hotspots with medium and high radiation levels, as well as filling gaps and holes in shielding structures.

[0007] The technical solution of the present invention to solve the above technical problems is:

[0008] According to one aspect of the present invention, a shielding putty material for high radiation areas comprises, by weight percentage, the following raw materials:

[0009] The invention comprises 72wt% to 86wt% of shielding agent, 1wt% to 3.2wt% of curing agent, 3.4wt% to 9.5wt% of ternary composite flame retardant, 0.1wt% to 0.15wt% of dispersant, 0.02%wt to 0.07wt% of defoaming agent, 1.8wt% to 3.5wt% of liquid flame retardant, and the balance is resin matrix, and the resin matrix comprises hyaluronic acid epoxy resin and bisphenol A epoxy resin.

[0010] Optionally, the hydantoin epoxy resin includes one or more of formula (1) to formula (3), which are as follows:

[0011]

[0012]

[0013] Among them, x, y, and z are all integers.

[0014] Optionally, the bisphenol A epoxy resin includes one or more of formula (4) to formula (5), which are as follows:

[0015]

[0016] Wherein, m and n are both integers.

[0017] Optionally, the hydantoin epoxy resin is:

[0018]

[0019] Among them, the epoxy value is between 0.52 and 0.74.

[0020] Optionally, the bisphenol A epoxy resin is:

[0021]

[0022] Among them, the epoxy value is between 0.48 and 0.54.

[0023] Optionally, the mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 4:1 to 15:1.

[0024] Optionally, the mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 5:1 to 12:1.

[0025] Optionally, the ternary composite flame retardant is a mixture of melamine grafted modified ammonium polyphosphate of formula (6), melamine cyanurate of formula (7), and triazine carbonizing agent of formula (8), specifically as follows:

[0026]

[0027] Optionally, the mass ratio of melamine grafted modified ammonium polyphosphate: melamine cyanurate: triazine carbon-forming agent in the ternary composite flame retardant is 4:1:2 to 5:1:5.

[0028] Optionally, the curing agent is an alicyclic amine curing agent.

[0029] Optionally, the alicyclic amine curing agent is isophoronediamine.

[0030] Optionally, the shielding agent is a mixture of one or more neutron shielding agents and photon shielding agents.

[0031] Optionally, the shielding agent is a mixture of one or more of boron carbide, hydroxy iron powder, and tungsten powder, and the particle size thereof is 2 to 5 μm.

[0032] Optionally, the dispersant is a mixture of one or more of γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and γ-glycidyloxypropyltrimethoxysilane.

[0033] Optionally, the defoaming agent is a silicon-based defoaming agent.

[0034] Optionally, the liquid flame retardant is an organophosphorus flame retardant.

[0035] According to another aspect of the present invention, there is provided a method for preparing a shielding putty material for a high radiation area, comprising:

[0036] Step S1, weighing hydantoin epoxy resin, bisphenol A epoxy resin, curing agent, ternary composite flame retardant, shielding agent, dispersant, defoaming agent, and liquid flame retardant respectively according to the weight percentages mentioned above;

[0037] Step S2, adding hydantoin epoxy resin, bisphenol A epoxy resin, and ternary composite flame retardant into a container, and mixing them evenly to obtain a first mixture;

[0038] Step S3, adding the shielding agent, dispersant, defoaming agent, and liquid flame retardant to the first mixture, and mixing them evenly to obtain a second mixture;

[0039] Step S4, adding the curing agent into the second mixture, and after vacuum stirring, obtaining a shielding putty material for high radiation areas.

[0040] Optionally, in step S2, the conditions for uniform mixing are: stirring at 23-30° C. and a rotation speed of 500-700 rpm for 20-30 min.

[0041] Optionally, in step S3, the conditions for uniform mixing are: stirring at 23-30° C. and a rotation speed of 30-70 rpm for 20-30 min.

[0042] Optionally, in step S4, the vacuum stirring conditions are: stirring for 10 to 20 minutes at 23 to 30° C., a rotation speed of 30 to 50 rpm, and a vacuum degree of ≤0.098 MPa.

[0043] Beneficial effects:

[0044] The shielding putty material for high radiation areas of the present invention and the preparation method thereof are obtained by compounding a low-viscosity, high-adhesion, non-flammable hyaluronic acid epoxy resin with a heat-resistant bisphenol A epoxy resin to obtain a resin matrix, and by introducing a low-addition amount of a ternary compounded high-efficiency flame retardant, the resin matrix is ​​flame-retardantly modified in coordination with a liquid flame retardant, so that the shielding putty material has good flame retardant properties. In addition, the liquid flame retardant has a wetting effect on the system, so that after adding a high-filled shielding filler, the shielding putty material has excellent bonding properties, high shielding properties, and convenient construction. Compared with the prior art, it has at least the following advantages:

[0045] (1) Different from the traditional hydroxide flame retardant and the binary compound phosphorus-nitrogen flame retardant, the ternary compound flame retardant used in the present invention can melt the flame retardant polymer first when the system is heated, and the melamine grafted modified ammonium polyphosphate will first be decomposed by heat to produce an acid with a strong dehydrating effect. As the temperature rises, the generated acid will undergo an esterification reaction with the macromolecular triazine carbonizing agent to dehydrate, and the generated water will gasify at high temperature. At the same time, high-purity melamine cyanurate will also produce ammonia (NH3) and carbon dioxide (CO2) when heated. The overflow of water vapor, NH3 and CO2 will cause the heated molten polymer to expand, and at the same time, it can also dilute the air and combustibles around the combustion reaction. The macromolecular triazine carbonizing agent is carbonized to form an expanded carbon layer under the dehydration effect of the acid generated by the melamine grafted modified ammonium polyphosphate. The continuous and dense expanded carbon layer can not only serve as a physical barrier to block heat transfer and mass transfer, but also the free radicals contained in it can form gaseous free radical reactions during the thermal degradation of the resin, which helps to terminate the free radical reaction chain in the thermal cracking of the epoxy resin and slow down the thermal degradation of the epoxy resin. The whole process has a flame retardant effect on the polymer from both the gas phase and the condensed phase, so that the shielding putty material of the present invention has good flame retardant properties, oxygen index>32, and vertical combustion reaches V0 level.

[0046] (2) Traditional ammonium polyphosphate is added to the resin by physical mixing, which has poor compatibility with the resin matrix and obvious reduction in mechanical properties. The present invention adopts melamine-grafted modified ammonium polyphosphate, which has good compatibility with epoxy resin. At the same time, the grafted side groups and the other two flame retardants contain amine groups, which can participate in the curing reaction of epoxy resin, improve the cross-linking density of the cured product, and thus make the material have good mechanical properties.

[0047] (3) The shielding putty material of the present invention, the added liquid flame retardant can, on the one hand, cooperate with the ternary composite flame retardant to perform flame retardant modification, and on the other hand, can adjust the viscosity of the system, thereby increasing the processability of the system and increasing the wettability between the resin and the bonding substrate, thereby improving the bonding strength of the shielding putty material.

[0048] (4) The shielding putty material of the present invention has active groups on the surface of the hydroxyl iron powder used. At the same time, the shielding agent modified by the dispersant has good interfacial compatibility with the epoxy resin and has no obvious aggregation, which is conducive to the preparation of a shielding putty material with uniform density. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic diagram of a method for preparing a shielding putty material for high radiation areas according to an embodiment of the present invention;

[0050] Figure 2 This is a scanning electron microscope image of the shielding putty material in Preparation Example 1 of the present invention.

[0051] Figure 3 The test specimens for the tensile properties, bending properties, Vicat softening point, oxygen index, vertical combustion, etc. of the shielding putty material for high radiation areas in Preparation Example 1 of the present invention;

[0052] Figure 4 The shielding performance test sample of the shielding putty material for high radiation area in Preparation Example 1 of the present invention;

[0053] Figure 5 The sample after vertical combustion performance of the shielding putty material for high radiation area in Preparation Example 1 of the present invention;

[0054] Figure 6 This is the vertical combustion performance test result of the shielding putty material for high radiation areas in Preparation Example 1 of the present invention.

[0055] Figure 7 This is the limiting oxygen index performance test result of the shielding putty material for high radiation areas in Preparation Example 1 of the present invention. DETAILED DESCRIPTION

[0056] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0057] The shielding putty material in the prior art uses a single component of aluminum hydroxide, which has low flame retardant efficiency, a large amount of flame retardant added, a significant increase in the viscosity of the shielding putty, and a limited amount of shielding filler. It is difficult to meet the requirements of neutron and photon shielding performance in medium and high radiation areas; or, because the active diluent used is an alkyl glycidyl ether, the flame retardancy of the shielding putty cannot be guaranteed; or, there is poor compatibility between the flame retardant and the resin matrix, resulting in a significant decrease in mechanical properties. The present invention provides a shielding putty material for high radiation areas, which is calculated by weight percentage.

[0058] The material composition includes:

[0059] The invention comprises 72wt% to 86wt% of shielding agent, 1wt% to 3.2wt% of curing agent, 3.4wt% to 9.5wt% of ternary composite flame retardant, 0.1wt% to 0.15wt% of dispersant, 0.02%wt to 0.07wt% of defoaming agent, 1.8wt% to 3.5wt% of liquid flame retardant, and the balance is a resin matrix, and the matrix comprises hyaluronic acid epoxy resin and bisphenol A epoxy resin.

[0060] Accordingly, the present invention also provides a method for preparing a shielding putty material for high radiation areas, comprising:

[0061] Step S1, weighing hydantoin epoxy resin, bisphenol A epoxy resin, curing agent, ternary composite flame retardant, shielding agent, dispersant, defoaming agent, and liquid flame retardant respectively according to the weight percentages mentioned above;

[0062] Step S2, adding hydantoin epoxy resin, bisphenol A epoxy resin, and ternary composite flame retardant into a container, and mixing them evenly to obtain a first mixture;

[0063] Step S3, adding the shielding agent, dispersant, defoaming agent, and liquid flame retardant to the first mixture, and mixing them evenly to obtain a second mixture;

[0064] Step S4, adding the curing agent into the second mixture, and after vacuum stirring, obtaining a shielding putty material for high radiation areas.

[0065] Example 1

[0066] like Figure 1 As shown, this embodiment discloses a shielding putty material for high radiation areas, and its raw material composition includes, by weight percentage:

[0067] The invention comprises 72wt% to 86wt% of shielding agent, 1wt% to 3.2wt% of curing agent, 3.4wt% to 9.5wt% of ternary composite flame retardant, 0.1wt% to 0.15wt% of dispersant, 0.02%wt to 0.07wt% of defoaming agent, 1.8wt% to 3.5wt% of liquid flame retardant, and the balance is a resin matrix, and the matrix comprises hyaluronic acid epoxy resin and bisphenol A epoxy resin.

[0068] In some embodiments, the hydantoin epoxy resin includes one or more of formula (1) to formula (3).

[0069] Specifically, formulas (1)-(3) are as follows:

[0070]

[0071]

[0072] Among them, x, y, and z are all integers.

[0073] In some embodiments, the bisphenol A epoxy resin includes one or more of formula (4) to formula (5).

[0074] Specifically, equations (4)-(5) are as follows:

[0075]

[0076] Wherein m and n are both integers.

[0077] In some more preferred embodiments, the hydantoin epoxy resin has a structural formula of formula (1) and an epoxy value between 0.52 and 0.74.

[0078]

[0079] In some more preferred embodiments, the bisphenol A epoxy resin has a structural formula of formula (4) and an epoxy value between 0.48 and 0.54.

[0080]

[0081] In some embodiments, the mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 4:1 to 15:1, and this mass ratio can ensure that the hydantoin epoxy resin can fully reduce the viscosity of the bisphenol A epoxy resin.

[0082] In some more preferred embodiments, the mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 5:1 to 12:1, which can ensure low viscosity of the system while ensuring that the cured product has good heat resistance.

[0083] In some embodiments, the ternary composite flame retardant is a mixture of melamine grafted modified ammonium polyphosphate, melamine cyanurate, and triazine carbon-forming agent, and the ternary composite flame retardant has the synergistic effect of condensed phase flame retardancy and gas phase flame retardancy, and can improve the flame retardant properties of the material. In addition, it can also participate in the curing reaction of the resin, exist in the system in a chemically bonded manner, increase the crosslinking density, and maintain good mechanical properties.

[0084] Specifically, the melamine grafted modified ammonium polyphosphate, melamine cyanurate, and triazine carbon-forming agent are shown in formula (6), formula (7), and formula (8), respectively.

[0085]

[0086] In some more preferred embodiments, the mass ratio of melamine grafted modified ammonium polyphosphate: melamine cyanurate: triazine carbon former in the ternary composite flame retardant is 4:1:2 to 5:1:5, which can make the ternary composite flame retardant have good flame retardant synergistic effect.

[0087] In some embodiments, the curing agent is an alicyclic amine curing agent.

[0088] In some more preferred embodiments, the alicyclic amine curing agent is an isophorone diamine curing agent, which has the characteristics of high hydrogen content, high strength after curing, easy operation, and room temperature curing. The amount used in this method is 1wt% to 3.2wt% of the total weight of the formula. Such a ratio can ensure the operability of the material and the strength of the material after curing.

[0089] In some embodiments, the shielding agent is a mixture of one or more of a neutron shielding agent and a photon shielding agent.

[0090] In some more specific embodiments, the shielding agent is a mixture of one or more of boron carbide, hydroxy iron powder, and tungsten powder, for example, tungsten powder alone, and a compound mixture of hydroxy iron powder and boron carbide, with a particle size of 2 to 5 μm, which can shield both neutrons and gamma rays.

[0091] In some embodiments, the dispersant is a mixture of one or more of γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0092] In some embodiments, the defoaming agent is a silicon-based defoaming agent.

[0093] In some embodiments, the liquid flame retardant is an organophosphorus flame retardant.

[0094] The shielding putty material for high radiation areas of this embodiment is obtained by compounding a low-viscosity, high-adhesion, non-flammable hyaluronic acid epoxy resin with a heat-resistant bisphenol A epoxy resin to obtain a resin matrix. By introducing a low amount of a ternary compounded high-efficiency flame retardant, the resin matrix is ​​flame-retardantly modified with a liquid flame retardant, so that the shielding putty material has good flame retardant properties. In addition, the liquid flame retardant has a wetting effect on the system, so that after adding a high-filling shielding agent, the shielding putty material is endowed with excellent bonding properties, high shielding properties, and convenient construction. The comprehensive performance is excellent. Compared with the prior art, it has at least the following advantages:

[0095] (1) Different from the traditional hydroxide flame retardant and the binary compound phosphorus-nitrogen flame retardant, the ternary compound flame retardant used in this embodiment can melt the flame retardant polymer first when the system is heated, and the melamine grafted modified ammonium polyphosphate will first decompose into an acid with a strong dehydrating effect when heated. As the temperature rises, the generated acid will undergo an esterification reaction with the macromolecular triazine carbonizing agent to dehydrate, and the generated water will gasify at high temperature. At the same time, high-purity melamine cyanurate will also produce ammonia (NH3) and carbon dioxide (CO2) when heated. The overflow of water vapor, NH3 and CO2 will cause the heated molten polymer to expand, and at the same time, it can also dilute the air and combustibles around the combustion reaction. The macromolecular triazine carbonizing agent is carbonized to form an expanded carbon layer under the dehydration effect of the acid generated by the melamine grafted modified ammonium polyphosphate. The continuous and dense expanded carbon layer can not only serve as a physical barrier to block heat transfer and mass transfer, but also the free radicals contained in it can form gaseous free radical reactions during the thermal degradation of the resin, which helps to terminate the free radical reaction chain in the thermal cracking of the epoxy resin and slow down the thermal degradation of the epoxy resin. The whole process has a flame retardant effect on the polymer from both the gas phase and the condensed phase, so that the shielding putty material of the present invention has good flame retardant properties, oxygen index>32, and vertical combustion reaches V0 level.

[0096] (2) Traditional ammonium polyphosphate is added to the resin by physical mixing, which has poor compatibility with the resin matrix and obvious reduction in mechanical properties. This embodiment uses melamine-grafted modified ammonium polyphosphate, which has good compatibility with epoxy resin. At the same time, the grafted side groups and the other two flame retardants contain amine groups, which can participate in the curing reaction of epoxy resin, improve the cross-linking density of the cured product, and thus make the material have good mechanical properties. The mechanism of the curing reaction is as follows:

[0097]

[0098] (3) In the shielding putty material of this embodiment, the added liquid flame retardant, on the one hand, serves the purpose of synergizing the ternary composite flame retardant for flame retardant modification; on the other hand, it can adjust the viscosity of the system, thereby increasing the processability of the system and increasing the wettability between the resin and the bonding substrate, thereby improving the bonding strength of the shielding putty material.

[0099] (4) The shielding putty material of this embodiment uses hydroxyl iron with active groups on its surface. The shielding agent modified with a dispersant has good interfacial compatibility with the epoxy resin and has no obvious aggregation, which is conducive to the preparation of a shielding putty material with uniform density.

[0100] Example 2

[0101] This embodiment discloses a method for preparing a shielding putty material for high radiation areas, comprising:

[0102] Step S1, weighing hydantoin resin, bisphenol A epoxy resin, curing agent, ternary composite flame retardant, shielding agent, dispersant, defoaming agent, and liquid flame retardant respectively according to the weight percentages described in the above Example 1;

[0103] Step S2, adding hydantoin resin, bisphenol A epoxy resin, and ternary composite flame retardant into a container, and mixing them evenly to obtain a first mixture;

[0104] Step S3, adding the shielding agent, dispersant, defoaming agent, and liquid flame retardant to the first mixture, and mixing them evenly to obtain a second mixture;

[0105] Step S4, adding a curing agent into the second mixture, stirring in vacuum, and curing reaction of the phenolic formaldehyde and the curing agent to obtain a shielding putty material for high radiation areas having a three-dimensional network structure.

[0106] In some embodiments, the conditions for uniform mixing in step S2 are: stirring at 23-30° C. and a rotation speed of 500-700 rpm for 20-30 min;

[0107] In some embodiments, the conditions for uniform mixing in step S3 are: stirring at 23-30° C. and a rotation speed of 30-70 rpm for 20-30 min.

[0108] In some embodiments, the vacuum stirring conditions in step S4 are: stirring for 10 to 20 minutes at 23 to 30° C., a rotation speed of 30 to 50 rpm, and a vacuum degree of ≤0.098 MPa. The specific construction can be carried out according to different working conditions.

[0109] The preparation method of the shielding putty material for high radiation areas of this embodiment is to compound the low viscosity, high adhesion, non-flammable hyaluronic acid epoxy resin with the heat-resistant bisphenol A epoxy resin to obtain the matrix resin, and the treated high-filling shielding agent is evenly dispersed in the matrix, and the liquid flame retardant and the ternary compound flame retardant in the system are synergistically flame retardant. In addition, the amine group contained in the ternary compound flame retardant participates in the curing reaction of the epoxy resin and exists in the system in the form of chemical bonds. The prepared shielding putty material has good flame retardancy, high adhesion, high temperature resistance, high shielding performance, and convenient construction. Several groups of specific preparations are provided below to describe the preparation method of the shielding putty material for high radiation areas of this embodiment in detail, as follows:

[0110] Preparation Example 1

[0111] Step S1, weighing 10wt% of hydantoin epoxy resin (hydantoin epoxy resin of formula (1), epoxy value 0.70-0.74), 2wt% of bisphenol A epoxy resin (model E51, epoxy value 0.48-0.54), 3.2wt% of isophorone diamine curing agent, 9.5wt% of ternary composite flame retardant (melamine grafted modified ammonium polyphosphate: melamine cyanurate: macromolecular carbon forming agent mass ratio of 5:1:5), 71wt% of hydroxy iron powder, 1wt% of boron carbide powder, 0.15wt% of dispersant (γ-aminopropyltriethoxysilane), 0.02wt% of defoamer (silicon defoamer, model HS-028), and 3.5wt% of liquid flame retardant (organophosphorus flame retardant, model CRP-002) respectively by weight percentage;

[0112] Step S2, adding the above-mentioned hydantoin epoxy resin of formula (1), E51, and the ternary composite flame retardant into a container, stirring for 25 minutes at 25° C. and a rotation speed of 600 rpm to obtain a first mixture;

[0113] Step S3, adding hydroxy iron powder, boron carbide powder, γ-aminopropyl triethoxysilane, silicon-based defoamer HS-028, and organophosphorus-based liquid flame retardant CRP-002 to the first mixture, and stirring for 30 minutes at 25° C. and a rotation speed of 70 rpm to obtain a second mixture;

[0114] Step S4, adding isophorone diamine curing agent into the second mixture, stirring for 10 minutes at 23° C., rotation speed 30 rpm, and vacuum degree ≤ 0.098 MPa, to obtain a shielding putty material for high radiation areas.

[0115] Figure 2 From the scanning electron microscope image of the material prepared in this preparation example, it can be seen that the shielding agent is evenly dispersed and has good interface bonding with the resin matrix.

[0116] Figure 3 The test specimens prepared in this preparation example are used for testing tensile properties, bending properties, Vicat softening point, oxygen index, vertical combustion, etc.;

[0117] Figure 4 This is a shielding performance test sample with a diameter of 11 cm and a thickness of 2 cm prepared in this preparation example.

[0118] Figure 5 The vertical combustion performance test specimen of the material prepared in this preparation example, the test data are as follows Figure 6 As shown, the vertical combustion level is at V0.

[0119] Figure 7 This is the test result of the limiting oxygen index performance of the material prepared in this preparation example. The oxygen index is 35.91%.

[0120] Preparation Example 2

[0121] Step S1, weighing 8wt% of hydantoin epoxy resin (hydantoin epoxy resin of formula (1), epoxy value 0.70-0.74), 1wt% of bisphenol A epoxy resin (model E44, epoxy value 0.41-0.47), 1.8wt% of isophorone diamine curing agent, 3.4wt% of ternary composite flame retardant (melamine grafted modified ammonium polyphosphate: melamine cyanurate: macromolecular carbon forming agent mass ratio of 4:1:2), 84wt% of tungsten powder, 0.1wt% of dispersant (γ-methacryloxypropyltrimethoxysilane), 0.02wt% of defoamer (silicon defoamer, model: HS-018), and 1.8wt% of liquid flame retardant (organophosphorus flame retardant, model: CRP-002) respectively by weight percentage;

[0122] Step S2, adding the above-mentioned hydantoin epoxy resin of formula (1), E44, and the ternary composite flame retardant into a container, stirring for 30 minutes at 30° C. and a rotation speed of 700 rpm to obtain a first mixture;

[0123] Step S3, adding tungsten powder, γ-methacryloxypropyltrimethoxysilane, silicon-based defoamer HS-018, and organophosphorus-based flame retardant CRP-001 to the first mixture, stirring at 30° C. and 55 rpm for 25 minutes to obtain a second mixture;

[0124] Step S4, adding isophorone diamine curing agent into the second mixture, stirring for 20 minutes at 30° C., rotation speed 50 rpm, and vacuum degree ≤ 0.098 MPa, to obtain a shielding putty material for high radiation areas.

[0125] Preparation Example 3

[0126] Step S1, weighing 6wt% of hydantoin epoxy resin (hydantoin epoxy resin of formula (2), epoxy value 0.52-0.55), 0.5wt% of bisphenol A epoxy resin (model: E51, epoxy value 0.48-0.54), 1wt% of isophorone diamine curing agent, 5wt% of ternary composite flame retardant (melamine grafted modified ammonium polyphosphate: melamine cyanurate: macromolecular carbon forming agent mass ratio of 4:1:4), 81wt% of tungsten powder, 3wt% of hydroxy iron powder, 2wt% of boron carbide, 0.13wt% of dispersant (γ-glycidyloxypropyltrimethoxysilane), 0.07wt% of silicon-based defoaming agent (model: HS-027), and 2.0wt% of organic phosphorus-based liquid flame retardant (dimethyl methylphosphonate) respectively by weight percentage;

[0127] Step S2, adding the above-mentioned hydantoin epoxy resin of formula (2), E51, and the ternary composite flame retardant into a container, stirring for 20 minutes at 23° C. and a rotation speed of 500 rpm to obtain a first mixture;

[0128] Step S3, adding tungsten powder, hydroxy iron powder, boron carbide, γ-glycidyloxypropyltrimethoxysilane, silicon-based defoamer HS-027, and dimethyl methylphosphonate to the mixture 1 of step 2, and stirring for 20 minutes at 23° C. and a rotation speed of 30 rpm to obtain a second mixture;

[0129] Step S4, adding isophorone diamine curing agent into the mixture 2 of step 3, stirring for 15 minutes at 25° C., rotation speed 40 rpm, and vacuum degree ≤ 0.098 MPa, to obtain a shielding putty material for high radiation areas.

[0130] Preparation Example 4

[0131] Step S1, weighing 8wt% of hydantoin epoxy resin (hydantoin epoxy resin of formula (3), epoxy value 0.70-0.74), 2wt% of bisphenol A epoxy resin (1wt% model: E51, epoxy value 0.48-0.54; 1wt% model: E44, epoxy value 0.41-0.47), 2.4wt% of isophorone diamine curing agent, 9wt% of ternary composite flame retardant (melamine bonding agent), Modified ammonium polyphosphate: melamine cyanurate: macromolecular carbonizing agent (mass ratio is 4:1:3), 76wt% tungsten powder, 0.12wt% dispersant (0.06wt% γ-glycidyloxypropyltrimethoxysilane; 0.06wt% γ-aminopropyltriethoxysilane), 0.05wt% silicon-based defoamer (model: HS-027), 2.5wt% organic phosphorus-based liquid flame retardant (dimethyl methylphosphonate);

[0132] Step S2, adding the above-mentioned hydantoin epoxy resin of formula (3), E51, E44, and the ternary composite flame retardant into a container, stirring for 20 minutes at 23° C. and a rotation speed of 500 rpm to obtain a first mixture;

[0133] Step S3, adding tungsten powder, γ-glycidyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, silicon-based defoamer HS-027, and dimethyl methylphosphonate to the mixture 1 of step 2, and stirring for 20 minutes at 23° C. and a rotation speed of 30 rpm to obtain a second mixture;

[0134] Step S4, adding isophorone diamine curing agent into the mixture 2 of step 3, stirring for 15 minutes at 25° C., rotation speed 40 rpm, and vacuum degree ≤ 0.098 MPa, to obtain a shielding putty material for high radiation areas.

[0135] Preparation Example 5

[0136] Step S1, weighing 15wt% of hydantoin epoxy resin (5wt% of hydantoin epoxy resin of formula (1), epoxy value 0.70-0.74; 5wt% of hydantoin epoxy resin of formula (2), epoxy value 0.52-0.55; 5wt% of hydantoin epoxy resin of formula (3), epoxy value 0.70-0.74), 1wt% of bisphenol A epoxy resin (model: E44, epoxy value 0.41-0.47), 2.5wt% of isocyanate, ... Phorone diamine curing agent, 6wt% ternary composite flame retardant (melamine grafted modified ammonium polyphosphate: melamine cyanurate: macromolecular carbonizing agent mass ratio of 5:1:4), 70wt% tungsten powder, 3wt% hydroxy iron powder, 2wt% boron carbide, 0.14wt% dispersant (γ-aminopropyltriethoxysilane), 0.04wt% silicon-based defoaming agent (model: HS-027), 2.5wt% organic phosphorus liquid flame retardant (dimethyl methylphosphonate);

[0137] Step S2, adding the above-mentioned hyaluronic acid epoxy resin of formula (1), hyaluronic acid epoxy resin of formula (2), hyaluronic acid epoxy resin of formula (3), E44, and ternary composite flame retardant into a container, stirring for 20 minutes at 23° C. and a rotation speed of 500 rpm to obtain a first mixture;

[0138] Step S3, adding tungsten powder, hydroxy iron powder, boron carbide, γ-glycidyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, silicon-based defoamer HS-027, and dimethyl methylphosphonate to the mixture 1 of step 2, and stirring for 20 minutes at 23° C. and a rotation speed of 30 rpm to obtain a second mixture;

[0139] Step S4, adding isophorone diamine curing agent into the mixture 2 of step 3, stirring for 15 minutes at 25° C., rotation speed 40 rpm, and vacuum degree ≤ 0.098 MPa, to obtain a shielding putty material for high radiation areas.

[0140] Comparative Example 1

[0141] Compared with Preparation Example 1, the difference is that the 12 wt % flame retardant in this comparative example is all aluminum hydroxide flame retardant.

[0142] The aluminum hydroxide in this formula has low flame retardant efficiency, an oxygen index of 25.2%, and stepless vertical combustion. After adding aluminum hydroxide, the viscosity of the system increases significantly, the material is difficult to shape, the tensile strength is 15.7MPa, the flexural strength is 26.8MPa, and the mechanical properties are low.

[0143] Comparative Example 2

[0144] Compared with Preparation Example 1, the difference is that in this comparative example, the mass ratio of melamine grafted modified ammonium polyphosphate: melamine cyanurate in the 9.5wt% composite flame retardant is changed to 5:1.

[0145] In this formula, no macromolecular carbonizing agent is added, and the synergistic flame retardant effect of melamine-grafted modified ammonium polyphosphate and melamine cyanurate is insufficient, and vertical combustion reaches V0 with an oxygen index of 28.3%.

[0146] Comparative Example 3

[0147] Compared with Preparation Example 1, the difference is that in this comparative example, the mass ratio of melamine grafted modified ammonium polyphosphate: melamine cyanurate: macromolecular carbon-forming agent in 9.5wt% ternary composite flame retardant is 5:1:4, thereby reducing the amount of macromolecular carbon-forming agent added.

[0148] In this formula, the amount of macromolecular carbonizing agent added is insufficient, the vertical combustion is V0 level, and the oxygen index is 31.5%.

[0149] Comparative Example 4

[0150] Compared with Preparation Example 1, the formula composition of this comparative example is changed to 19.4wt% polyethylene, 1.48wt% boron carbide, and 79% lead powder commonly used in the prior art.

[0151] In this formula, the hydrogen content is high and the neutron shielding coefficient is high (2.29), but the material cannot be bonded, and the mechanical properties, Vicat softening point, and flame retardant properties (oxygen index 21.4%, vertical combustion grade is stepless) are all lower than those of Preparation Example 1.

[0152] Comparative Example 5

[0153] Compared with Preparation Example 2, the difference is that in this comparative example, 3.4 wt% of the ternary composite flame retardant is replaced by all melamine-grafted modified ammonium polyphosphate.

[0154] In this formula, the melamine-grafted modified ammonium polyphosphate has good compatibility with the resin, excellent mechanical properties, and vertical combustion is V0 level, but the flame retardant effect is not enough, and the oxygen index is 30.8% (<32%).

[0155] Comparative Example 6

[0156] Compared with Preparation Example 2, the difference is that in this comparative example, the organic phosphorus liquid flame retardant is changed to 4.0 wt %.

[0157] In this formula, the oxygen index reaches 32%, but too much organic phosphorus liquid flame retardant is added, resulting in a significant decrease in the mechanical properties of the material, with a tensile strength of 16.2 MPa.

[0158] Product effect test:

[0159] The performance of the shielding putty materials for high radiation areas prepared in Preparation Examples 1 to 5 and the materials prepared in Comparative Examples 1 to 6 were tested. The test standards of the comparative examples and the preparation examples were the same. The test results are shown in Tables 1 and 2.

[0160] Table 1 Preparation Example Test Results

[0161]

[0162]

[0163] Table 2 Comparative Example Test Results

[0164]

[0165] It can be seen from Table 1 that the Vicat softening points of the shielding putty materials prepared in Preparation Examples 1 to 5 are all above 200°C, and the linear expansion coefficients are all lower than 1×10 -4 K -1 , the bonding strength is above 10MPa, indicating that the material of the present invention has good thermal properties and good bonding strength, which is conducive to the use of repair and bonding conditions; in addition, due to the joint action of the ternary compound flame retardant and the liquid flame retardant, the material combustion level of the shielding putty materials prepared in Preparation Example 1-Preparation Example 5 all reaches V0 level, and the oxygen index is above 32%, which has good fire retardant performance and greatly improves the safety of material use. The ternary compound flame retardant participates in the resin curing reaction, and the material has good mechanical properties. It is worth mentioning that the 2cm shielding putty material has excellent radiation shielding effect, so it can be widely used in equipment, pipelines and radiation hotspot shielding with medium and high radiation levels, as well as filling gaps and holes in shielding structures.

[0166] It can be seen from Table 1 and Table 2 that when the same amount of flame retardant is added, the oxygen index is less than 32 when the amount of single-function flame retardant, binary flame retardant and carbon-forming agent added is insufficient. Poor system processability, excessive amount of liquid flame retardant, and addition of unmodified flame retardant will all lead to a decrease in the mechanical properties of the material, with a tensile strength of less than 20MPa.

[0167] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A shielding putty material for high radiation areas, characterized in that: The raw material composition includes, by weight percentage: The invention comprises 72wt% to 86wt% of shielding agent, 1wt% to 3.2wt% of curing agent, 3.4wt% to 9.5wt% of ternary composite flame retardant, 0.1wt% to 0.15wt% of dispersant, 0.02%wt to 0.07wt% of defoaming agent, 1.8wt% to 3.5wt% of liquid flame retardant, and the balance is resin matrix, and the resin matrix comprises hyaluronic acid epoxy resin and bisphenol A epoxy resin.

2. The shielding putty material for high radiation areas according to claim 1, characterized in that: The hydantoin epoxy resin comprises one or more of formula (1) to formula (3), Among them, x, y, and z are all integers.

3. The shielding putty material for high radiation areas according to claim 1, characterized in that: The bisphenol A type epoxy resin includes one or more of formula (4) to formula (5), Wherein, m and n are both integers.

4. The shielding putty material for high radiation areas according to claim 1, characterized in that: The hydantoin epoxy resin is: Among them, the epoxy value is between 0.52 and 0.

74.

5. The shielding putty material for high radiation areas according to claim 1, characterized in that: The bisphenol A type epoxy resin is: Among them, the epoxy value is between 0.48 and 0.

54.

6. The shielding putty material for high radiation areas according to claim 1, characterized in that: The mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 4:1 to 15:

1.

7. The shielding putty material for high radiation areas according to claim 1, characterized in that: The mass ratio of the hydantoin epoxy resin to the bisphenol A epoxy resin is 5:1 to 12:

1.

8. The shielding putty material for high radiation areas according to claim 1, characterized in that: The ternary composite flame retardant is a mixture of melamine grafted modified ammonium polyphosphate of formula (6), melamine cyanurate of formula (7), and a triazine carbonizing agent of formula (8).

9. The shielding putty material for high radiation areas according to claim 8, characterized in that: The mass ratio of melamine grafted modified ammonium polyphosphate: melamine cyanurate: triazine carbon former in the ternary composite flame retardant is 4:1:2-5:1:

5.

10. The shielding putty material for high radiation areas according to claim 1, characterized in that: The curing agent is an alicyclic amine curing agent.

11. The shielding putty material for high radiation areas according to claim 10, characterized in that: The alicyclic amine curing agent is isophorone diamine.

12. The shielding putty material for high radiation areas according to claim 1, characterized in that: The shielding agent is a mixture of one or more of a neutron shielding agent and a photon shielding agent.

13. The shielding putty material for high radiation areas according to claim 12, characterized in that: The shielding agent is a mixture of one or more of boron carbide, hydroxy iron powder and tungsten powder, and its particle size is 2-5 μm.

14. The shielding putty material for high radiation areas according to claim 1, characterized in that: The dispersant is a mixture of one or more of γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane and γ-glycidyloxypropyltrimethoxysilane.

15. The shielding putty material for high radiation areas according to claim 1, characterized in that: The defoaming agent is a silicon-based defoaming agent.

16. The shielding putty material for high radiation areas according to claim 1, characterized in that: The liquid flame retardant is an organic phosphorus flame retardant.

17. A method for preparing a shielding putty material for high radiation areas, characterized in that: include: Step S1, weighing hydantoin epoxy resin, bisphenol A epoxy resin, curing agent, ternary composite flame retardant, shielding agent, dispersant, defoaming agent, and liquid flame retardant respectively according to the weight percentages described in any one of claims 1 to 16; Step S2, adding hydantoin epoxy resin, bisphenol A epoxy resin, and ternary composite flame retardant into a container, and mixing them evenly to obtain a first mixture; Step S3, adding the shielding agent, dispersant, defoaming agent, and liquid flame retardant to the first mixture, and mixing them evenly to obtain a second mixture; Step S4, adding the curing agent into the second mixture, and after vacuum stirring, obtaining a shielding putty material for high radiation areas.

18. The shielding putty material for high radiation areas according to claim 17, characterized in that: In step S2, the conditions for uniform mixing are: stirring at 23-30° C. and a rotation speed of 500-700 rpm for 20-30 min.

19. The shielding putty material for high radiation areas according to claim 17, characterized in that: In step S3, the conditions for uniform mixing are: stirring at 23-30° C. and a rotation speed of 30-70 rpm for 20-30 min.

20. The shielding putty material for high radiation areas according to claim 17, characterized in that: In step S4, the vacuum stirring conditions are: stirring for 10 to 20 minutes at 23 to 30° C., a rotation speed of 30 to 50 rpm, and a vacuum degree of ≤0.098 MPa.

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