Pressure-resistant and deformation-resistant plywood and preparation method thereof
Through nitriding and silicon modification treatment, the resin performance of plywood is improved, and combined with flame retardant epoxy resin and graphene, the lack of performance of plywood in high temperature and fire source environments is solved, and good flame retardant, high temperature resistance and Pressure and deformation resistance ensures its stability and safety in different application scenarios.
Patent Information
- Application Number
- CN202411547380.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-01-07
AI Technical Summary
Existing plywood is inadequate in flame retardant and high-temperature resistance when facing fire sources or high-temperature environments, resulting in fire spread and structural deformation, and is prone to permanent deformation under long-term loads, such as depression, warping or fracture, affecting its stability. and functional integrity.
Using a pressure-resistant and deformation-resistant plywood preparation method, the pre-product of epoxy resin is obtained by mixing bisphenol acid, epoxy chloride and catalyst, and the heat resistance and resistance of the resin are improved by nitriding and silicon modification treatment. The flameability is then mixed with flame retardant epoxy resin, sodium hydroxide, bentonite, coupling agent, thickener, curing agent and graphene to form an adhesive, coated onto a pine board and subjected to hot pressing curing.
The flame retardant performance, high temperature resistance and pressure resistance of plywood are significantly improved, ensuring that there is no deformation or fire spread in high temperature environments, and maintaining structural stability and functional integrity.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of plywood production, in particular to a pressure-resistant and deformation-resistant plywood and a preparation method thereof. Background Art
[0002] Plywood has important value in modern construction and manufacturing, which is mainly reflected in the following aspects: First, plywood has become an indispensable material in modern construction due to its excellent physical properties and stability. Compared with traditional solid wood materials, plywood has higher strength and stability due to its multi-layer structure and staggered fiber arrangement. This allows it to withstand greater loads and stresses in building structures such as walls, floors and roofs. Second, plywood's moisture resistance and deformation resistance also make it stable under various environmental conditions. In addition, in the field of interior decoration, plywood is widely used in furniture making, wall decoration and floor laying. Its excellent processing properties allow plywood to be made into furniture of various shapes and sizes, such as wardrobes, tables and cabinets. At the same time, the surface of plywood can be treated with various decorative treatments, including painting, filming or covering with high-grade wood grain paper to meet the needs of different styles and functions. Plywood's wear resistance and easy cleaning also make it excellent in places with high frequency of use, such as commercial spaces and home environments. Third, plywood has high production efficiency and relatively low cost, can be produced on a large scale, and is highly economical during transportation and installation. Due to its high strength and light weight, plywood has low transportation and construction costs, which can effectively shorten the construction project cycle and reduce overall costs.
[0003] However, in many application scenarios, such as interior decoration, public places and working environments, plywood materials may be exposed to fire sources. Therefore, it is necessary to improve the flame retardant properties of plywood materials to effectively slow down the spread of fire and protect the lives and property of personnel. In addition, in some special environments, such as industrial production workshops, high-temperature work areas or kitchens, the high-temperature resistance of plywood is particularly important. By improving the high-temperature resistance, it can be ensured that the plywood will not deform, crack or melt in a high-temperature environment, thereby maintaining its structural stability and functional integrity. In addition, the compression and deformation resistance of plywood determines its performance when subjected to long-term loads and pressure. This performance improvement can effectively prevent plywood from permanent deformation due to pressure during use, such as dents, warping or fractures. In furniture manufacturing, floor laying and building structures, enhanced compression and deformation resistance helps maintain the shape stability and structural integrity of plywood, avoiding unsightly and functional disorders caused by long-term use or heavy pressure.
[0004] In order to overcome the defects of the prior art, the present invention provides a pressure-resistant and deformation-resistant plywood and a preparation method thereof. Summary of the invention
[0005] The object of the present invention is to provide a pressure-resistant and deformation-resistant plywood and a preparation method thereof, so as to solve the problems in the prior art.
[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A method for preparing a pressure-resistant and deformation-resistant plywood comprises the following steps: Step 1: Mix diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride, react at 120-140°C for 2-3h under nitrogen environment, cool to 45-55°C after the reaction, add sodium hydroxide solution dropwise to the reaction system, continue to react for 5-6h, cool and centrifuge to obtain supernatant after the reaction, wash and rotary evaporate to obtain epoxy resin pre-product; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 70-80°C, condense and reflux and stir for 4-6 hours, then add 2-hydroxy-3-nitrobenzonitrile, continue to react for 3-4 hours, and after the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; Step 3: Mix the nitrilized epoxy resin and the solvent butyl acetate, heat and stir at 40-50°C until the intermediate is completely dissolved, then heat to 50-55°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 8-10 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; Step 4: Mix silicon-modified epoxy resin, flame-retardant epoxy resin, epichlorohydrin, sodium hydroxide, bentonite, coupling agent, thickener, curing agent, deionized water and graphene, and stir for 1-2 hours at a temperature of 25-30°C and a rotation speed of 2000-3000r / min to obtain an adhesive; dry several pine boards at 50-80°C, apply the adhesive to the surface of the pine boards, and then bond the pine boards together, and obtain plywood after hot pressing and curing at 200-230°C for 30-50min.
[0007] More optimally, in step 1, the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:(2.0-2.3):7.6.
[0008] More optimally, in step 2, the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:(1.0-1.2).
[0009] More optimally, in step three, the reaction mass ratio of the nitrilated epoxy resin and dimethyldichlorosilane is (8-10):1.
[0010] More optimally, in step four, the contents of the components of the adhesive are: in parts by mass, 40-50 parts of silicon-modified epoxy resin, 30-40 parts of flame-retardant epoxy resin, 15-25 parts of epichlorohydrin, 10-15 parts of sodium hydroxide, 5-10 parts of bentonite, 1-5 parts of coupling agent, 1-5 parts of thickener, 1-5 parts of curing agent, 50-60 parts of deionized water, and 3-8 parts of graphene; the coupling agent is a titanate coupling agent; the thickener is carboxymethyl cellulose; and the curing agent is dimethylimidazole.
[0011] More optimally, the preparation process of the flame retardant epoxy resin is as follows: melamine and deionized water are mixed, stirred at 90-95°C for 10-15 minutes, the pH is adjusted to 4.5-5.0, stirring is continued for 30-40 minutes, bisphenol A glycidyl ether type epoxy resin is added, the reaction is continued for 4-5 hours, and after the reaction is completed, the flame retardant epoxy resin is obtained by cooling in an ice water bath, filtering, washing and drying.
[0012] More optimally, the reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is (6.5-7.5):30:80.
[0013] Beneficial effects of the present invention: The feature of the present invention is that in step one, by adding diphenolic acid, epichlorohydrin, benzyltriethylammonium chloride and sodium hydroxide solution, diphenolic acid and epichlorohydrin undergo substitution reaction to prepare epoxy resin pre-product. In this step, the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is set to 1: (2.0-2.3): 7.6, so the hydroxyl group in the diphenolic acid is not completely reacted, and it can be further reacted with 2-hydroxy-3-nitrobenzonitrile containing nitro group in step two to prepare nitrified epoxy resin. In this step, the nitrile group is introduced into the epoxy resin structure, which can significantly improve the heat resistance and flame retardancy of the resin on the one hand, and the nitrile group can self-crosslink and epoxy resin to form a structure with an interpenetrating crosslinked network, thereby improving the curing crosslinking degree and heat resistance of the resin.
[0014] The present invention is characterized in that, in step three, by adding nitrilized epoxy resin, butyl acetate, dimethyldichlorosilane and dibutyltin dilaurate, a silicon-modified epoxy resin is prepared. The nitrilized epoxy resin added in this step is prepared by adding 2-hydroxy-3-nitrobenzene in step two, so the nitrilized epoxy resin also contains a certain amount of hydroxyl. In step three, the nitrilized epoxy resin reacts with dimethyldichlorosilane under the catalytic action of dibutyltin dilaurate to prepare a silicon-modified epoxy resin. In this step, organosilicon is further introduced into the epoxy resin structure, and the hydrophobicity, oxidation resistance and high temperature resistance of the epoxy resin can be improved by introducing organosilicon.
[0015] The feature of the present invention is that, in step 4, first, a flame retardant epoxy resin is prepared by adding melamine and bisphenol A glycidyl ether type epoxy resin. In this step, the amino group of melamine reacts with the hydroxyl group in the bisphenol A glycidyl ether type epoxy resin to prepare a flame retardant epoxy resin containing a large amount of flame retardant element nitrogen. Then, silicon-modified epoxy resin, flame retardant epoxy resin, epichlorohydrin, sodium hydroxide, bentonite, coupling agent, thickener, curing agent, deionized water and graphene are mixed to obtain an adhesive. After drying a number of pine boards, an adhesive is applied, and then the pine boards are bonded to each other, and plywood is obtained after hot pressing and curing. In summary, the plywood obtained by the present invention has good flame retardant properties, high temperature resistance, and pressure resistance and deformation resistance, and therefore has broad application prospects in the field of plywood production technology. DETAILED DESCRIPTION
[0016] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0017] Source of raw materials: Bisphenol A glycidyl ether type epoxy resin, provided by Jiangsu Nantong Xingchen Synthetic Materials Co., Ltd., industrial grade, viscosity 7000 (mPa.s, 25°C); titanate coupling agent, provided by Nanjing Xuanhao New Materials Technology Co., Ltd., model NXH-401; bentonite, provided by Shijiazhuang Baijiang Mineral Products Co., Ltd., particle size 325μm; graphene, provided by Jiangxi Shuobang New Materials Technology Co., Ltd., diameter 0.8μm; carboxymethyl cellulose, provided by Hebei Chaoyan Insulation Materials Co., Ltd., density 0.3g / ml; pine board, provided by Tianjin Zhongzhu Industrial Co., Ltd., thickness 10mm; in terms of mass parts, one portion is 1g.
[0018] Example 1: Step 1: diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride are mixed, reacted at 140°C for 3h under nitrogen environment, cooled to 55°C after the reaction, and then sodium hydroxide solution is added dropwise to the reaction system, and the reaction is continued for 6h. After the reaction is completed, the supernatant is cooled, centrifuged, washed, and rotary evaporated to obtain an epoxy resin pre-product; wherein the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:2.3:7.6; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 80°C, condense and reflux and stir for 6 hours, then add 2-hydroxy-3-nitrobenzonitrile, and continue to react for 4 hours. After the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; wherein the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:1.2; Step 3: Mix the nitrilized epoxy resin and solvent butyl acetate, heat and stir at 50°C until the intermediate is completely dissolved, then heat to 55°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 10 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; the reaction mass ratio of the nitrilized epoxy resin and dimethyldichlorosilane is 8:1; Step 4: Mix melamine and deionized water, stir at 95°C for 15 minutes, adjust the pH to 5.0, continue stirring for 40 minutes, add bisphenol A glycidyl ether type epoxy resin, continue reacting for 5 hours, and after the reaction is completed, cool in an ice water bath, filter, wash, and dry to obtain a flame retardant epoxy resin; wherein the reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is 6.5:30:80; 40g of silicon-modified epoxy resin, 30g of flame-retardant epoxy resin, 15g of epichlorohydrin, 10g of sodium hydroxide, 5g of bentonite, 1g of coupling agent, 1g of carboxymethyl cellulose, 1g of dimethylimidazole, 50g of deionized water and 5g of graphene were mixed, and stirred for 2h at a temperature of 30°C and a rotation speed of 3000r / min to obtain an adhesive; several pine boards were dried at 80°C, the adhesive was applied to the surface of the pine boards, and the pine boards were bonded together, and plywood was obtained after hot pressing and curing at 230°C for 50min.
[0019] Example 2: Step 1: diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride are mixed, reacted at 130°C for 2.5h under nitrogen environment, cooled to 50°C after the reaction, and then sodium hydroxide solution is added dropwise to the reaction system, and the reaction is continued for 5.5h. After the reaction is completed, the supernatant is cooled, centrifuged, washed, and rotary evaporated to obtain an epoxy resin pre-product; wherein the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:2.3:7.6; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 75°C, condense and reflux and stir for 5 hours, then add 2-hydroxy-3-nitrobenzonitrile, and continue to react for 3.5 hours. After the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; wherein the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:1.2; Step 3: Mix the nitrilized epoxy resin and solvent butyl acetate, heat and stir at 45°C until the intermediate is completely dissolved, then heat to 53°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 9 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; the reaction mass ratio of the nitrilized epoxy resin and dimethyldichlorosilane is 2:1.5; Step 4: Mix melamine and deionized water, stir at 93°C for 12 minutes, adjust the pH to 4.7, continue stirring for 35 minutes, add bisphenol A glycidyl ether type epoxy resin, continue to react for 4.5 hours, and after the reaction is completed, cool in an ice water bath, filter, wash, and dry to obtain a flame retardant epoxy resin; wherein the reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is 6.5:30:80; 40g of silicon-modified epoxy resin, 30g of flame-retardant epoxy resin, 15g of epichlorohydrin, 10g of sodium hydroxide, 5g of bentonite, 1g of coupling agent, 1g of carboxymethyl cellulose, 1g of dimethylimidazole, 50g of deionized water and 5g of graphene were mixed, and stirred for 1.5h at a temperature of 27°C and a rotation speed of 2500r / min to obtain an adhesive; several pine boards were dried at 45°C, the adhesive was applied to the surface of the pine boards, and the pine boards were bonded together, and plywood was obtained after hot pressing and curing at 210°C for 40min.
[0020] Example 3: Step 1: diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride are mixed, reacted at 120°C for 2h under nitrogen environment, cooled to 45°C after the reaction, and then sodium hydroxide solution is added dropwise to the reaction system, and the reaction is continued for 5h. After the reaction is completed, the supernatant is cooled, centrifuged, washed, and rotary evaporated to obtain an epoxy resin pre-product; wherein the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:2.3:7.6; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 70°C, condense and reflux and stir for 4 hours, then add 2-hydroxy-3-nitrobenzonitrile, and continue to react for 3 hours. After the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; wherein the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:1.2; Step 3: Mix the nitrilized epoxy resin and solvent butyl acetate, heat and stir at 40°C until the intermediate is completely dissolved, then heat to 50°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 8 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; the reaction mass ratio of the nitrilized epoxy resin and dimethyldichlorosilane is 2:1.5; Step 4: Mix melamine and deionized water, stir at 90°C for 10 minutes, adjust the pH to 4.5, continue stirring for 30 minutes, add bisphenol A glycidyl ether type epoxy resin, continue to react for 4 hours, and after the reaction is completed, cool in an ice water bath, filter, wash, and dry to obtain a flame retardant epoxy resin; wherein the reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is 6.5:30:80; 40g of silicon-modified epoxy resin, 30g of flame-retardant epoxy resin, 15g of epichlorohydrin, 10g of sodium hydroxide, 5g of bentonite, 1g of coupling agent, 1g of carboxymethyl cellulose, 1g of dimethylimidazole, 50g of deionized water and 5g of graphene were mixed, and stirred for 1h at a temperature of 25°C and a rotation speed of 2000r / min to obtain an adhesive; several pine boards were dried at 50°C, the adhesive was applied to the surface of the pine boards, and the pine boards were bonded together, and plywood was obtained after hot pressing and curing at 200°C for 30min.
[0021] Comparative Example 1: The modification treatment of the epoxy resin pre-product in step 2 and step 3 is removed, and the rest is the same as Example 1, and the specific steps are as follows: Step 1: diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride are mixed, and reacted at 140° C. for 3 hours under a nitrogen environment. After the reaction is completed, the temperature is cooled to 55° C., and then sodium hydroxide solution is added dropwise to the reaction system, and the reaction is continued for 6 hours. After the reaction is completed, the supernatant is cooled, centrifuged, washed, and rotary evaporated to obtain an epoxy resin pre-product; wherein the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:2.3:7.6; Step 2: Mix melamine and deionized water, stir at 95°C for 15 minutes, adjust the pH to 5.0, continue stirring for 40 minutes, add bisphenol A glycidyl ether type epoxy resin, continue reacting for 5 hours, and after the reaction is completed, cool in an ice water bath, filter, wash, and dry to obtain a flame retardant epoxy resin; wherein the reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is 6.5:30:80; 40g of epoxy resin preproduct, 30g of flame retardant epoxy resin, 15g of epichlorohydrin, 10g of sodium hydroxide, 5g of bentonite, 1g of coupling agent, 1g of carboxymethyl cellulose, 1g of dimethylimidazole, 50g of deionized water and 5g of graphene were mixed, and stirred for 2h at a temperature of 30°C and a rotation speed of 3000r / min to obtain an adhesive; several pine boards were dried at 80°C, the adhesive was applied to the surface of the pine boards, and then the pine boards were bonded together, and plywood was obtained after hot pressing and curing at 230°C for 50min.
[0022] Comparative Example 2: The preparation step of the flame retardant epoxy resin in step 4 is removed, and the rest is the same as Example 1, and the specific steps are as follows: Step 1: diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride are mixed, and reacted at 140° C. for 3 hours under a nitrogen environment. After the reaction is completed, the temperature is cooled to 55° C., and then sodium hydroxide solution is added dropwise to the reaction system, and the reaction is continued for 6 hours. After the reaction is completed, the supernatant is cooled, centrifuged, washed, and rotary evaporated to obtain an epoxy resin pre-product; wherein the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:2.3:7.6; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 80°C, condense and reflux and stir for 6 hours, then add 2-hydroxy-3-nitrobenzonitrile, and continue to react for 4 hours. After the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; wherein the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:1.2; Step 3: Mix the nitrilized epoxy resin and solvent butyl acetate, heat and stir at 50°C until the intermediate is completely dissolved, then heat to 55°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 10 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; the reaction mass ratio of the nitrilized epoxy resin and dimethyldichlorosilane is 8:1; Step 4: Mix 40g of silicon-modified epoxy resin, 15g of epichlorohydrin, 10g of sodium hydroxide, 5g of bentonite, 1g of coupling agent, 1g of carboxymethyl cellulose, 1g of dimethylimidazole, 50g of deionized water and 5g of graphene, and stir for 2h at a temperature of 30°C and a rotation speed of 3000r / min to obtain an adhesive; dry several pine boards at 80°C, apply the adhesive to the surface of the pine boards, and then bond the pine boards together, and obtain plywood after hot pressing and curing at 230°C for 50min.
[0023] Detection test: Thermal stability test: The adhesive prepared by the present invention was cured at 200°C and used as a sample. The test was performed with reference to a TGA4000 thermogravimetric analyzer. The test range of the sample was from 30°C to 800°C, the heating rate was 10°C / min, the test atmosphere was N2, and the thermal stability of the sample was analyzed by testing the temperature corresponding to the maximum mass loss.
[0024] Flame retardant performance test: The adhesive prepared by the present invention was cured at 200°C as a sample, and the combustion characteristics of the sample were tested using a vertical combustion instrument in accordance with ISO-5660-1-2022 standard. The size of the test sample was 100mm×100m×3mm. The results are shown in the following table: Conclusion: The dosage of Examples 1 to 3 remains unchanged, and only some reaction parameters are modified. From the experimental data, it can be seen that the various properties of the samples have no obvious fluctuations.
[0025] Comparative Example 1: The modification treatment of the epoxy resin pre-product in step 2 and step 3 is removed, and the rest is the same as Example 1. It can be seen from the experimental data that compared with Example 1, T max The temperature of the epoxy resin was reduced to 403℃, and the combustion grade was V-1. The reasons were as follows: in step 2 and step 3, the epoxy resin pre-product was subjected to nitrification treatment and silicon modification treatment in sequence to obtain a silicon-modified epoxy resin with an interpenetrating cross-linked network structure. This structure can effectively improve the high temperature resistance and thermal stability of the sample, and the modified resin also contains flame retardant elements N and Si. Therefore, the modification treatment of the epoxy resin pre-product in step 2 and step 3 was removed, and the thermal stability and flame retardancy were reduced, so T max Reduced, combustion level is V-1.
[0026] Comparative Example 2: The preparation step of the flame-retardant epoxy resin in step 4 is removed, and the rest is the same as Example 1. It can be seen from the experimental data that compared with Example 1, the combustion grade is V-1. The reason is analyzed as follows: the flame-retardant epoxy resin contains a large amount of flame-retardant element N. Therefore, after the flame-retardant epoxy resin is removed, the flame retardancy is reduced, and the combustion grade is V-1.
[0027] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process method article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process method article or device.
[0028] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for preparing a pressure-resistant and deformation-resistant plywood, characterized in that: The following steps are involved: Step 1: Mix diphenolic acid, epichlorohydrin and catalyst benzyltriethylammonium chloride, react at 120-140°C for 2-3h under nitrogen environment, cool to 45-55°C after the reaction, add sodium hydroxide solution dropwise to the reaction system, continue to react for 5-6h, cool and centrifuge to obtain supernatant after the reaction, wash and rotary evaporate to obtain epoxy resin pre-product; Step 2: Mix the epoxy resin pre-product, potassium carbonate and dimethyl sulfoxide, heat to 70-80°C, condense and reflux and stir for 4-6 hours, then add 2-hydroxy-3-nitrobenzonitrile, continue to react for 3-4 hours, and after the reaction is completed, pour the reaction product into deionized water to obtain a solid product, and then crush, wash and vacuum dry to obtain a nitrified epoxy resin; Step 3: Mix the nitrilized epoxy resin and the solvent butyl acetate, heat and stir at 40-50°C until the intermediate is completely dissolved, then heat to 50-55°C, add dimethyldichlorosilane and dibutyltin dilaurate, and continue to react for 8-10 hours. After the reaction is completed, wash and distill under reduced pressure to obtain a silicon-modified epoxy resin; Step 4: Mix silicon-modified epoxy resin, flame-retardant epoxy resin, epichlorohydrin, sodium hydroxide, bentonite, coupling agent, thickener, curing agent, deionized water and graphene, and stir for 1-2 hours at a temperature of 25-30°C and a rotation speed of 2000-3000r / min to obtain an adhesive; dry several pine boards at 50-80°C, apply the adhesive to the surface of the pine boards, and then bond the pine boards together, and obtain plywood after hot pressing and curing at 200-230°C for 30-50min.
2. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 1, characterized in that: In step 1, the reaction molar ratio of diphenolic acid, epichlorohydrin and sodium hydroxide is 1:(2.0-2.3):7.
6.
3. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 1, characterized in that: In step 2, the reaction molar ratio of the epoxy resin pre-product and 2-hydroxy-3-nitrobenzonitrile is 1:(1.0-1.2).
4. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 1, characterized in that: In step 3, the reaction mass ratio of the nitrilated epoxy resin and dimethyldichlorosilane is (8-10):
1.
5. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 1, characterized in that: In step 4, the contents of each component of the adhesive are: by mass, 40-50 parts of silicon-modified epoxy resin, 30-40 parts of flame-retardant epoxy resin, 15-25 parts of epichlorohydrin, 10-15 parts of sodium hydroxide, 5-10 parts of bentonite, 1-5 parts of coupling agent, 1-5 parts of thickener, 1-5 parts of curing agent, 50-60 parts of deionized water, and 3-8 parts of graphene; the coupling agent is a titanate coupling agent; the thickener is carboxymethyl cellulose; and the curing agent is dimethylimidazole.
6. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 5, characterized in that: Preparation process of flame retardant epoxy resin: melamine and deionized water are mixed, stirred at 90-95°C for 10-15 minutes, pH is adjusted to 4.5-5.0, stirring is continued for 30-40 minutes, bisphenol A glycidyl ether type epoxy resin is added, and the reaction is continued for 4-5 hours. After the reaction is completed, the flame retardant epoxy resin is obtained by cooling in an ice water bath, filtering, washing and drying.
7. The method for preparing a pressure-resistant and deformation-resistant plywood according to claim 6, characterized in that: The reaction mass ratio of melamine, bisphenol A glycidyl ether type epoxy resin and deionized water is (6.5-7.5):30:
80.
8. A pressure-resistant and deformation-resistant plywood, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 7.