Aramid fibrid / carbon fiber-based X-ray shielding paper as well as preparation method and application thereof
By using aramid precipitation fiber and carbon fiber-based materials, combined with Bi2O3 and La2O3 fillers, vacuum suction filtration and phenolic resin curing processes, the problems of poor structural strength and limited shielding performance of traditional X-ray shielding materials are solved, and efficient and lightweight X-ray shielding effect is achieved.
Patent Information
- Application Number
- CN202510384809.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-28
- Publication Date
- 2025-06-27
AI Technical Summary
Traditional X-ray shielding materials have problems such as poor structural strength, limited shielding efficiency and a lot of space.
Aramid precipitation fibers and carbon fiber-based materials were used as substrates, Bi2O3 and La2O3 were added as fillers, and shielding paper with excellent X-ray shielding properties and mechanical properties were prepared by vacuum suction filtration and phenolic resin curing processes.
It realizes the lightweight, efficient shielding, environmental tolerance and easy processing of X-ray shielding paper, which has more advantages than traditional materials.
Smart Images
Figure CN120211138A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of shielding materials, and particularly relates to an aramid precipitated fiber / carbon fiber-based X-ray shielding paper, a preparation method thereof, and an application thereof. Background Art
[0002] X-rays are a type of electromagnetic radiation with high penetrability and are widely used in fields such as clinical diagnosis, food processing, X-ray imaging, etc.; however, long-term or excessive exposure to X-rays may cause harm to human health; therefore, it is particularly important to develop efficient radiation protection materials.
[0003] Currently, traditional X-ray shielding materials mainly include lead-based materials, concrete-based materials, and metal-based materials. However, the above materials generally have limitations such as poor structural strength, limited shielding efficiency, and large occupied space; specifically, for lead-based materials, due to the certain chemical toxicity of lead, long-term contact or inhalation of lead dust may cause harm to human health, and lead has a large scattering amount for low-energy X-rays (such as X-rays with an energy of 40.0 - 80.0 keV), which may increase the radiation dose in the surrounding environment; for concrete-based materials, the shielding efficiency of pure concrete is limited, and for high-intensity X-ray radiation, a relatively thick concrete layer is required to achieve an effective shielding effect; in addition, the structural performance of concrete is poor and it is easily damaged by external forces, thereby affecting its shielding effect; for metal-based materials, they have a certain shielding ability for X-rays, but compared with lead-based materials, their shielding efficiency is lower, and a thicker shielding layer is required to achieve the same shielding effect. Some metal-based materials (such as iron) are prone to corrosion and oxidation in a humid environment, affecting their shielding efficiency and service life. Summary of the Invention
[0004] Aiming at the technical problems existing in the prior art, the present invention provides an aramid precipitated fiber / carbon fiber-based X-ray shielding paper, a preparation method thereof, and an application thereof, so as to solve the technical problems that traditional X-ray shielding materials generally have poor structural strength, limited shielding efficiency, and large occupied space.
[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: The present invention provides a preparation method of an aramid precipitated fiber / carbon fiber-based X-ray shielding paper, including: After soaking aramid precipitated fibers in water, carbon fibers are added to obtain an aramid precipitated / carbon fiber mixed suspension; Bi2O3 and La2O3 are added to the aramid precipitated / carbon fiber mixed suspension, and are fully defibrated and dispersed to obtain a slurry suspension; The slurry suspension is subjected to composite filtration treatment, cold pressing, and drying to obtain an aramid precipitated fiber / carbon fiber paper base; The aramid fibril / carbon fiber paper base is impregnated in a phenolic resin impregnating solution, and after hot pressing, an aramid fibril / carbon fiber-based X-ray shielding paper is obtained.
[0006] Furthermore, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 20wt%-40wt%, and the mass fraction of carbon fibers is 60wt%-80wt%.
[0007] Furthermore, during the process of subjecting the slurry suspension to composite suction filtration, cold pressing, and drying to obtain the aramid fibril / carbon fiber paper base, the cold pressing temperature is 25°C, the pressure is 4MPa, and the cold pressing time is 5-10min.
[0008] Furthermore, during the process of subjecting the slurry suspension to composite suction filtration, cold pressing, and drying to obtain the aramid fibril / carbon fiber paper base, drying is carried out under vacuum conditions, and the drying temperature is 90-110°C.
[0009] Furthermore, the solid content of phenolic resin in the phenolic resin impregnating solution is 3%-10%, and the impregnation time is 10-15min.
[0010] Furthermore, during the process of impregnating the aramid fibril / carbon fiber paper base in the phenolic resin impregnating solution and obtaining the aramid fibril / carbon fiber-based X-ray shielding paper after hot pressing, the hot pressing temperature is 150°C, and the pressure is 10-15Mpa.
[0011] Furthermore, the basis weight of the aramid fibril / carbon fiber-based X-ray shielding paper is 200g / m 2 .
[0012] Furthermore, the thickness of the aramid fibril / carbon fiber-based X-ray shielding paper is 0.478-0.505mm.
[0013] The present invention also provides an aramid fibril / carbon fiber-based X-ray shielding paper, which is prepared by using the preparation method of the aramid fibril / carbon fiber-based X-ray shielding paper described above.
[0014] The present invention also provides an application of the aramid fibril / carbon fiber-based X-ray shielding paper, and the aramid fibril / carbon fiber-based X-ray shielding paper is used in the field of X-ray shielding.
[0015] Compared with the prior art, the beneficial effects of the present invention are: The preparation method of the aramid fibril carbon fiber-based X-ray shielding paper provided by the present invention uses a fiber paper-based material of aramid fibrils and carbon fibers as the matrix. By introducing Bi2O3 and La2O3, two high atomic number elements with synergistic effects, namely Bi and La, are used as fillers. A vacuum filtration combined with a phenolic resin curing process is adopted to obtain an X-ray shielding paper with excellent X-ray shielding performance and mechanical properties. Among them, the high toughness and impact resistance of aramid fibrils are utilized to complement the high rigidity of carbon fibers synergistically, forming a matrix with both strength and toughness, effectively supporting the X-ray fillers and avoiding the increase in brittleness caused by the addition of fillers. Using rare earth oxides La2O3 and Bi2O3 as dual-phase fillers, La2O3 is used to compensate for the weak absorption region of Bi2O3 for X-rays. Through the synergistic effect of the two high atomic number elements, La2O3 and Bi2O3, a high shielding efficiency in the entire X-ray energy range is achieved. Secondly, through the papermaking process, it is ensured that the fibers and fillers are evenly distributed, reducing filler agglomeration, avoiding local weak points in the shielding performance, and fixing the fillers by impregnating with phenolic resin so that the fillers are not easily detached. The present invention realizes multiple advantages of lightweight, high-efficiency shielding, environmental tolerance, and easy processability of the X-ray shielding paper, which is of great significance for promoting the industrial development of X-ray shielding materials. Description of the Drawings
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0017] Figure 1 It is the surface SEM image of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 1; Figure 2 It is the cross-sectional SEM image of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 1; Figure 3 It is the X-ray shielding efficiency diagram of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Examples 1-8. Detailed Embodiments
[0018] In order to make the technical problems, technical solutions and beneficial effects solved by this application more clearly understood, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application; obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.
[0019] The present invention provides a method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper, comprising the following steps: Step 1: Immerse aramid fibrid in water and then add carbon fiber to obtain an aramid fibrid / carbon fiber mixed suspension; in the aramid fibrid / carbon fiber mixed suspension, the mass fraction of aramid fibrid is 20wt%-40wt%, and the mass fraction of carbon fiber is 60wt%-80wt%.
[0020] Step 2: Add Bi2O3 and La2O3 to the aramid fibrid / carbon fiber mixed suspension, and fully disperse and deflocculate to obtain a slurry suspension.
[0021] Step 3: Perform composite filtration treatment on the slurry suspension, cold press, and dry to obtain aramid fibrid / carbon fiber paper substrate; among them, the cold press temperature is 25°C, the pressure is 4MPa, and the cold press time is 5-10min; drying is carried out under vacuum conditions, and the drying temperature is 90-110°C.
[0022] Step 4: Immerse the aramid fibrid / carbon fiber paper substrate in a phenolic resin impregnating solution for impregnation treatment, and hot press to obtain aramid fibrid / carbon fiber-based X-ray shielding paper; the solid content of phenolic resin in the phenolic resin impregnating solution is 3%-10%, and the impregnation time is 10-15min; the hot press temperature is 150°C, the pressure is 10-15Mpa; the basis weight of the aramid fibrid / carbon fiber-based X-ray shielding paper is 200g / m 2 , and the thickness is 0.478-0.505mm.
[0023] Preparation principle: The preparation method of the aramid fibril / carbon fiber-based X-ray shielding paper according to the present invention uses a fiber paper-based material composed of composite aramid fibrils and carbon fibers as the matrix; among them, carbon fibers have excellent properties of low density, high modulus, high strength, and electrical conductivity, and aramid fibrils have high toughness and impact resistance, which can complement the high rigidity advantage of carbon fibers and enhance synergistically to form a matrix with both strength and toughness, effectively supporting the X-ray filler and avoiding the increase in brittleness caused by the addition of the filler; rare earth oxides La2O3 and Bi2O3 are introduced as a two-phase filler. By virtue of the characteristics of Bi2O3 having a high atomic number, thermal stability, biocompatibility, and low toxicity, the L absorption edge of Bi2O3 is located at ~13 keV, and the K absorption edge is located at ~90 keV, while the K absorption edge of La2O3 is 38.9 - 63.3 keV, so as to compensate for the weak absorption region of X-rays of Bi2O3 and achieve the synergistic enhancement effect of making full use of the two high-atomic-number elements of Bi and La, and realizing high shielding efficiency within the entire X-ray energy range; secondly, a vacuum filtration combined with phenolic resin curing process is adopted to ensure the uniform distribution of fibers and fillers, reduce filler agglomeration, avoid local weak points in shielding performance, and fix the fillers by impregnating with phenolic resin, so that the fillers are not easily detached, and an X-ray shielding paper with excellent X-ray shielding performance and mechanical properties is obtained.
[0024] The aramid fibril / carbon fiber-based X-ray shielding paper prepared by the present invention has a uniform and dense internal structure, realizes high shielding efficiency within the entire X-ray energy range by using the synergistic effect of two high-Z elements, is lighter than traditional lead or metal-based shielding materials, and is suitable for the field of X-ray shielding; the present invention realizes multiple advantages of lightweight, high-efficiency shielding, environmental tolerance, and easy processability, and has important significance for promoting the industrial development of X-ray shielding materials.
[0025] Example 1 The present Example 1 provides a preparation method of an aramid fibril / carbon fiber-based X-ray shielding paper, which includes the following steps: Step 1: Tear the aramid fibrils, and add the aramid fibrils torn to a preset size into deionized water. After soaking for 3 h, add carbon fibers and stir to obtain an aramid fibril / carbon fiber mixed suspension; among them, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 20 wt%, and the mass fraction of carbon fibers is 80 wt%.
[0026] Step 2: Add 0.1 g of Bi2O3 and 0.1 g of La2O3 to the aramid fibril / carbon fiber mixed suspension in Step 1, and add 10 mL of PEO with a mass fraction of 1.5%, and fully disperse and loosen to obtain a slurry suspension.
[0027] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press and perform cold pressing at a cold pressing temperature of 25°C and a pressure of 4 MPa for 5 minutes to obtain a cold-pressed wet paper web.
[0028] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid fibril / carbon fiber paper substrate; wherein, the drying temperature is 90°C and the drying time is 10 minutes.
[0029] Step 5: Immerse the aramid fibril / carbon fiber paper substrate in Step 4 in a phenolic resin impregnating solution for 10 minutes to obtain an impregnated aramid fibril / carbon fiber paper substrate; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 3%.
[0030] Step 6: Transfer the impregnated aramid fibril / carbon fiber paper substrate in Step 5 to a flat vulcanizer and perform hot pressing at a hot pressing temperature of 150°C and a pressure of 10 MPa for 15 minutes to obtain an aramid fibril / carbon fiber-based X-ray shielding paper with a thickness of 0.478 mm; wherein, the basis weight of the aramid fibril / carbon fiber-based X-ray shielding paper is 200 g / m 2 。
[0031] Performance testing: Perform performance testing on the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 1 of this embodiment, and the test results are as follows: The aramid fibril / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 57.4% - 70.8% in the range of 20 - 70 keV, and the tensile strength is 19.1 MPa; therefore, the aramid fibril / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0032] As shown in the appendix Figure 1-2 shown, the appendix Figure 1 shows the surface SEM image of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 1 of this embodiment, and the appendix Figure 2 shows the surface SEM image of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 1 of this embodiment; as can be seen from the appendix Figure 1-2 it can be seen that filler particles are distributed on the surface of the aramid fibril / carbon fiber-based X-ray shielding paper, and the cross-section of the aramid fibril / carbon fiber-based X-ray shielding paper has a highly ordered layered structure, which can effectively improve the mechanical strength of the composite paper.
[0033] Example 2 This Example 2 provides a method for preparing an aramid fibril / carbon fiber-based X-ray shielding paper, including the following steps: Step 1: Tear the aramid fibrillated fiber, add the torn aramid fibrillated fiber to deionized water, add carbon fiber after soaking for 4 h, and stir to obtain an aramid fibrillated fiber / carbon fiber mixed suspension; wherein, in the aramid fibrillated fiber / carbon fiber mixed suspension, the mass fraction of aramid fibrillated fiber is 20 wt%, and the mass fraction of carbon fiber is 80 wt%.
[0034] Step 2: Add 0.1 g of Bi2O3 and 0.1 g of La2O3 to the aramid fibrillated fiber / carbon fiber mixed suspension in Step 1, and add 20 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0035] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press, and perform cold pressing at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 10 min to obtain a cold-pressed wet paper web.
[0036] Step 4: Dry the cold-pressed wet paper web in Step 3 under vacuum conditions to obtain an aramid fibrillated fiber / carbon fiber paper substrate; wherein, the drying temperature is 90 °C and the drying time is 10 min.
[0037] Step 5: Immerse the aramid fibrillated fiber / carbon fiber paper substrate in Step 4 in a phenolic resin impregnating solution for 15 min to obtain an impregnated aramid fibrillated fiber / carbon fiber paper substrate; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 5%.
[0038] Step 6: Transfer the impregnated aramid fibrillated fiber / carbon fiber paper substrate in Step 5 to a flat vulcanizer, and perform hot pressing at a hot pressing temperature of 150 °C and a pressure of 10 MPa for 15 min to obtain an aramid fibrillated fiber / carbon fiber-based X-ray shielding paper with a thickness of 0.482 mm; wherein, the basis weight of the aramid fibrillated fiber / carbon fiber-based X-ray shielding paper is 200 g / m 2 。
[0039] Performance detection: Perform performance detection on the aramid fibrillated fiber / carbon fiber-based X-ray shielding paper prepared in Example 2, and the detection results are as follows: the aramid fibrillated fiber / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 59.1%-71.4% in the range of 20-70 keV, and the tensile strength is 18.4 MPa; therefore, the aramid fibrillated fiber / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0040] Example 3 Example 3 provides a method for preparing aramid fibril / carbon fiber-based X-ray shielding paper, which includes the following steps: Step 1: Tear the aramid fibrils, add the torn aramid fibrils with a preset size to deionized water, add carbon fibers after soaking for 3 h, and stir to obtain an aramid fibril / carbon fiber mixed suspension; wherein, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 20 wt%, and the mass fraction of carbon fibers is 80 wt%.
[0041] Step 2: Add 0.2 g of Bi2O3 and 0.2 g of La2O3 to the aramid fibril / carbon fiber mixed suspension in Step 1, and add 20 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0042] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press, and perform cold pressing at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 5 min to obtain a cold-pressed wet paper web.
[0043] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain aramid fibril / carbon fiber paper-based; wherein, the drying temperature is 110 °C and the drying time is 10 min.
[0044] Step 5: Immerse the aramid fibril / carbon fiber paper-based in Step 4 in a phenolic resin impregnating solution for 15 min to obtain an impregnated aramid fibril / carbon fiber paper-based; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 5%.
[0045] Step 6: Transfer the impregnated aramid fibril / carbon fiber paper-based in Step 5 to a flat vulcanizer, and perform hot pressing at a hot pressing temperature of 150 °C and a pressure of 10 MPa for 15 min to obtain aramid fibril / carbon fiber-based X-ray shielding paper with a thickness of 0.481 mm; wherein, the basis weight of the aramid fibril / carbon fiber-based X-ray shielding paper is 200 g / m 2 .
[0046] Performance detection: Perform performance detection on the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 3, and the detection results are as follows: the aramid fibril / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 61.5%-76.8% in the range of 20-70 keV, and the tensile strength is 15.1 MPa; therefore, the aramid fibril / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0047] Example 4 Example 4 provides a method for preparing aramid precipitated fiber / carbon fiber-based X-ray shielding paper, which includes the following steps: Step 1: Tear the aramid precipitated fibers, add the aramid precipitated fibers torn to a preset scale into deionized water, add carbon fibers after soaking for 4 h, and stir to obtain an aramid precipitated / carbon fiber mixed suspension; wherein, in the aramid precipitated / carbon fiber mixed suspension, the mass fraction of aramid precipitated fibers is 30 wt%, and the mass fraction of carbon fibers is 70 wt%.
[0048] Step 2: Add 0.2 g of Bi2O3 and 0.2 g of La2O3 into the aramid precipitated / carbon fiber mixed suspension in Step 1, and add 15 mL of PEO with a mass fraction of 1.5%, and fully disperse and loosen to obtain a slurry suspension.
[0049] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press, and perform cold pressing at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 10 min to obtain a cold-pressed wet paper web.
[0050] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid precipitated fiber / carbon fiber paper base; wherein, the drying temperature is 110 °C and the drying time is 10 min.
[0051] Step 5: Immerse the aramid precipitated fiber / carbon fiber paper base in Step 4 in a phenolic resin impregnating solution for 10 min to obtain an impregnated aramid precipitated fiber / carbon fiber paper base; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 5%.
[0052] Step 6: Transfer the impregnated aramid precipitated fiber / carbon fiber paper base in Step 5 to a flat vulcanizer, and perform hot pressing at a hot pressing temperature of 150 °C and a pressure of 15 MPa for 15 min to obtain aramid precipitated fiber / carbon fiber-based X-ray shielding paper with a thickness of 0.483 mm; wherein, the basis weight of the aramid precipitated fiber / carbon fiber-based X-ray shielding paper is 200 g / m 2 .
[0053] Performance testing: The performance of the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 4 was tested, and the test results were as follows: The aramid fibril / carbon fiber-based X-ray shielding paper achieved an X-ray attenuation efficiency of 60.3% - 75.6% in the range of 20 - 70 keV, and the tensile strength was 15.9 MPa. Therefore, the aramid fibril / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0054] Example 5 This Example 5 provides a method for preparing an aramid fibril / carbon fiber-based X-ray shielding paper, which includes the following steps: Step 1: Tear the aramid fibrils, and add the torn aramid fibrils with a preset size to deionized water. After soaking for 3 h, add carbon fibers and stir to obtain an aramid fibril / carbon fiber mixed suspension. Among them, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 30 wt%, and the mass fraction of carbon fibers is 70 wt%.
[0055] Step 2: Add 0.3 g of Bi2O3 and 0.3 g of La2O3 to the aramid fibril / carbon fiber mixed suspension in Step 1, and add 15 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0056] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web. Then, transfer the composite wet paper web to a cold press and perform cold pressing at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 10 min to obtain a cold-pressed wet paper web.
[0057] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid fibril / carbon fiber paper substrate. Among them, the drying temperature is 110 °C, and the drying time is 10 min.
[0058] Step 5: Immerse the aramid fibril / carbon fiber paper substrate in Step 4 in a phenolic resin impregnating solution for 15 min to obtain an impregnated aramid fibril / carbon fiber paper substrate. Among them, the solid content of phenolic resin in the phenolic resin impregnating solution is 5%.
[0059] Step 6: Transfer the impregnated aramid fibril / carbon fiber paper substrate in Step 5 to a flat vulcanizer and perform hot pressing at a hot pressing temperature of 150 °C and a pressure of 10 MPa for 15 min to obtain an aramid fibril / carbon fiber-based X-ray shielding paper with a thickness of 0.485 mm. Among them, the basis weight of the aramid fibril / carbon fiber-based X-ray shielding paper is 200 g / m 2 .
[0060] Performance detection: Perform performance detection on the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 5. The detection results are as follows: The aramid fibril / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 65.5% - 80.8% in the range of 20 - 70 keV, and the tensile strength is 14.1 MPa. Therefore, the aramid fibril / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0061] Example 6 This Example 6 provides a preparation method of aramid fibril / carbon fiber-based X-ray shielding paper, including the following steps: Step 1: Tear the aramid fibrils, and add the aramid fibrils torn to a preset size into deionized water. After soaking for 4 h, add carbon fibers and stir to obtain an aramid fibril / carbon fiber mixed suspension; wherein, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 40 wt%, and the mass fraction of carbon fibers is 60 wt%.
[0062] Step 2: Add 0.3 g of Bi2O3 and 0.3 g of La2O3 to the aramid fibril / carbon fiber mixed suspension in Step 1, and add 20 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0063] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press and perform cold pressing at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 5 min to obtain a cold-pressed wet paper web.
[0064] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid fibril / carbon fiber paper base; wherein, the drying temperature is 110 °C and the drying time is 10 min.
[0065] Step 5: Immerse the aramid fibril / carbon fiber paper base in Step 4 in a phenolic resin impregnating solution for 15 min to obtain an impregnated aramid fibril / carbon fiber paper base; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 5%.
[0066] Step 6: Transfer the impregnated aramid fibril / carbon fiber paper base in Step 5 to a flat vulcanizer and perform hot pressing at a hot pressing temperature of 150 °C and a pressure of 15 MPa for 15 min to obtain an aramid fibril / carbon fiber-based X-ray shielding paper with a thickness of 0.491 mm; wherein, the basis weight of the aramid fibril / carbon fiber-based X-ray shielding paper is 200 g / m2 。
[0067] Performance testing: Perform performance testing on the aramid fibril / carbon fiber-based X-ray shielding paper prepared in Example 6. The test results are as follows: The aramid fibril / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 66.3% - 80.3% in the range of 20 - 70 keV, and the tensile strength is 15.8 MPa. Therefore, the aramid fibril / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0068] Example 7 Example 7 provides a preparation method of aramid fibril / carbon fiber-based X-ray shielding paper, including the following steps: Step 1: Tear the aramid fibrils, and add the torn aramid fibrils to deionized water. After soaking for 4 h, add carbon fibers and stir to obtain an aramid fibril / carbon fiber mixed suspension; wherein, in the aramid fibril / carbon fiber mixed suspension, the mass fraction of aramid fibrils is 40 wt%, and the mass fraction of carbon fibers is 60 wt%.
[0069] Step 2: Add 0.4 g of Bi2O3 and 0.4 g of La2O3 to the aramid fibril / carbon fiber mixed suspension in Step 1, and add 20 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0070] Step 3: Use a vacuum filtration device to perform composite filtration on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press and perform cold pressing at a cold pressing temperature of 25°C and a pressure of 4 MPa for 10 min to obtain a cold-pressed wet paper web.
[0071] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid fibril / carbon fiber paper substrate; wherein, the drying temperature is 90°C and the drying time is 10 min.
[0072] Step 5: Immerse the aramid fibril / carbon fiber paper substrate in Step 4 in a phenolic resin impregnating solution for 10 min to obtain an impregnated aramid fibril / carbon fiber paper substrate; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 10%.
[0073] Step 6: Transfer the impregnated aramid nanofiber / carbon fiber paper base in Step 5 to a flat vulcanizing machine, and perform hot pressing treatment at a hot pressing temperature of 150 °C and a pressure of 15 MPa for 15 min to obtain an aramid nanofiber / carbon fiber-based X-ray shielding paper with a thickness of 0.494 mm; wherein, the basis weight of the aramid nanofiber / carbon fiber-based X-ray shielding paper is 200 g / m 2 .
[0074] Performance testing: Perform performance testing on the aramid nanofiber / carbon fiber-based X-ray shielding paper prepared in Example 7. The test results are as follows: The aramid nanofiber / carbon fiber-based X-ray shielding paper achieves an X-ray attenuation efficiency of 68.5% - 81.8% in the range of 20 - 70 keV, and the tensile strength is 12.9 MPa; therefore, the aramid nanofiber / carbon fiber-based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0075] Example 8 Example 8 provides a preparation method of an aramid nanofiber / carbon fiber-based X-ray shielding paper, including the following steps: Step 1: Tear the aramid nanofibers, and add the torn aramid nanofibers to deionized water. After soaking for 3 h, add carbon fibers and stir to obtain an aramid nanofiber / carbon fiber mixed suspension; wherein, in the aramid nanofiber / carbon fiber mixed suspension, the mass fraction of aramid nanofibers is 40 wt%, and the mass fraction of carbon fibers is 60 wt%.
[0076] Step 2: Add 0.5 g of Bi2O3 and 0.5 g of La2O3 to the aramid nanofiber / carbon fiber mixed suspension in Step 1, and add 20 mL of PEO with a mass fraction of 1.5%, and fully disperse to obtain a slurry suspension.
[0077] Step 3: Use a vacuum filtration device to perform composite filtration treatment on the slurry suspension in Step 2 to obtain a composite wet paper web; then, transfer the composite wet paper web to a cold press and perform cold pressing treatment at a cold pressing temperature of 25 °C and a pressure of 4 MPa for 10 min to obtain a cold-pressed wet paper web.
[0078] Step 4: Under vacuum conditions, dry the cold-pressed wet paper web in Step 3 to obtain an aramid nanofiber / carbon fiber paper base; wherein, the drying temperature is 110 °C and the drying time is 10 min.
[0079] Step 5: Immerse the aramid precipitated fiber / carbon fiber paper substrate in step 4 in a phenolic resin impregnating solution for 15 min to obtain an impregnated aramid precipitated fiber / carbon fiber paper substrate; wherein, the solid content of phenolic resin in the phenolic resin impregnating solution is 10%.
[0080] Step 6: Transfer the impregnated aramid precipitated fiber / carbon fiber paper substrate in step 5 to a flat vulcanizing machine and perform hot pressing treatment at a hot pressing temperature of 150 °C and a pressure of 15 MPa for 15 min to obtain an aramid precipitated fiber / carbon fiber based X-ray shielding paper with a thickness of 0.505 mm; wherein, the basis weight of the aramid precipitated fiber / carbon fiber based X-ray shielding paper is 200 g / m 2 .
[0081] Performance testing: Perform performance testing on the aramid precipitated fiber / carbon fiber based X-ray shielding paper prepared in Example 8 of this embodiment. The test results show that the aramid precipitated fiber / carbon fiber based X-ray shielding paper achieves an X-ray attenuation efficiency of 69.3% - 85.5% in the range of 20 - 70 keV, and the tensile strength is 11.1 MPa; therefore, the aramid precipitated fiber / carbon fiber based X-ray shielding paper has good X-ray shielding efficiency and mechanical strength, and excellent comprehensive performance.
[0082] As shown in the Figure 3 attachment, the Figure 3 attachment gives the X-ray shielding efficiency diagram of the aramid precipitated fiber / carbon fiber based X-ray shielding paper prepared in Examples 1 - 8 of the present invention; wherein, x L y B is the abbreviation of the aramid precipitated fiber / carbon fiber based X-ray shielding paper with different loadings of Bi2O3 and La2O3; L represents La2O3, and B represents Bi2O3; x represents the loading of La2O3, x taking values from [0 g, 0.5 g]; y represents the loading of Bi2O3, y taking values from [0 g, 0.5 g]; it can be seen from the Figure 3 attachment that as the tube voltage decreases (X-ray energy decreases), the X-ray shielding efficiency (AE%) of the aramid precipitated fiber / carbon fiber based X-ray shielding paper increases significantly, and low-energy X-rays are more easily absorbed by the material, while high-energy X-rays have stronger penetrability; in addition, when the filler increases from 0 g (no filler) to 0.5 g, the shielding efficiency gradually increases.
[0083] The aramid fibril / carbon fiber-based X-ray shielding paper provided by the present invention, its preparation method and application use a fiber paper-based material with excellent mechanical properties as the matrix, introduce two high atomic number elements, La and Bi, with a synergistic effect as fillers, and adopt a vacuum filtration combined with phenolic resin curing process to ensure the uniform distribution of fibers and fillers, reduce filler agglomeration, avoid local weak points in the shielding performance, and fix the fillers by impregnating with phenolic resin so that the fillers are not easily detached, obtaining an X-ray shielding paper with excellent X-ray shielding performance and mechanical properties; the aramid fibril / carbon fiber-based X-ray shielding paper prepared by the present invention has a uniform and dense internal structure, utilizes the synergistic effect of La and Bi to achieve high shielding efficiency in the entire X-ray energy range, is lighter than traditional lead or metal-based shielding materials, and is suitable for the new field of X-ray shielding.
[0084] The above embodiments are only one of the implementation manners capable of implementing the technical solution of the present invention. The scope of protection required by the present invention is not only limited by this embodiment, but also includes any changes, substitutions and other implementation manners that are easily conceivable by any person skilled in the art within the technical scope disclosed by the present invention.
Claims
1. A method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper, characterized in that: include: After immersing aramid fiber precipitation in water, carbon fiber is added to obtain aramid fiber precipitation / carbon fiber mixed suspension; Adding Bi2O3 and La2O3 to the aramid precipitate / carbon fiber mixed suspension, fully dispersing and dispersing them to obtain a slurry suspension; The slurry suspension is subjected to composite suction filtration, cold pressing, and drying to obtain aramid fiber precipitate / carbon fiber paper base; The aramid fibrid / carbon fiber paper base is immersed in a phenolic resin impregnation solution, and then hot-pressed to obtain the aramid fibrid / carbon fiber-based X-ray shielding paper.
2. The method for preparing an aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: In the aramid fiber precipitation / carbon fiber mixed suspension, the mass fraction of aramid fiber precipitation is 20wt%-40wt%, and the mass fraction of carbon fiber is 60wt%-80wt%.
3. The method for preparing an aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The slurry suspension is subjected to composite suction filtration, cold pressing, and drying to obtain the aramid fiber precipitation / carbon fiber paper base, wherein the cold pressing temperature is 25° C., the pressure is 4 MPa, and the cold pressing time is 5-10 min.
4. The method for preparing an aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The slurry suspension is subjected to composite suction filtration, cold pressing, and drying to obtain the aramid fibrid / carbon fiber paper base, and the drying is performed under vacuum conditions at a drying temperature of 90-110°C.
5. The method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The solid content of phenolic resin in the phenolic resin impregnation solution is 3%-10%, and the impregnation time is 10-15 minutes.
6. The method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The aramid fibrid / carbon fiber paper base is immersed in a phenolic resin impregnation solution and hot-pressed to obtain the aramid fibrid / carbon fiber-based X-ray shielding paper, wherein the hot-pressing temperature is 150° C. and the pressure is 10-15 MPa.
7. The method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The aramid fibrid / carbon fiber based X-ray shielding paper has a basis weight of 200 g / m 2 .
8. The method for preparing aramid fibrid / carbon fiber-based X-ray shielding paper according to claim 1, characterized in that: The thickness of the aramid fibrid / carbon fiber-based X-ray shielding paper is 0.478-0.505 mm.
9. Aramid fibrid / carbon fiber based X-ray shielding paper, characterized in that: The aramid fibrid / carbon fiber-based X-ray shielding paper is prepared by the method for preparing the aramid fibrid / carbon fiber-based X-ray shielding paper according to any one of claims 1 to 8.
10. The use of an aramid fibrid / carbon fiber-based X-ray shielding paper as claimed in claim 9, characterized in that: The aramid fibrid / carbon fiber-based X-ray shielding paper is used in the field of X-ray shielding.