Preparation method of silicon whisker copolymerized epoxy resin and silicon whisker copolymerized epoxy resin

Abstract

The invention provides a preparation method of silicon whisker copolymerized epoxy resin and the silicon whisker copolymerized epoxy resin, and relates to the technical field of epoxy resin.The preparation method comprises the steps that S100, raw materials including bisphenol A, bisphenol F, 5.5 dimethyl hydantoin, epichlorohydrin and isopropanol are put into a reaction kettle, heated, stirred and dissolved, and evenly mixed; controlling the reaction temperature, and preparing mixed epoxy resin of bisphenol A epoxy resin, bisphenol F epoxy resin and hydantoin epoxy resin under the action of a catalyst A; s200, after the mixed epoxy resin is prepared, adding a branching agent, silicon whiskers and a coupling agent into the reaction kettle; the preparation method comprises the following steps: adding bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin and silicon whiskers into a reaction kettle, controlling reaction conditions, dropwise adding a catalyst B to promote a branching reaction, and carrying out a branching coupling reaction on the bisphenol A epoxy resin, the bisphenol F epoxy resin, the hydantoin epoxy resin and the silicon whiskers in the reaction kettle to obtain the silicon whisker copolymerized epoxy resin. The silicon whisker copolymerized epoxy resin prepared by the invention can improve the underwater bonding performance with the surface of a base material.

Description

Technical Field

[0001] The present application relates to the technical field of epoxy resins, and in particular to a preparation method of a silicon whisker copolymerized epoxy resin and a silicon whisker copolymerized epoxy resin. Background Art

[0002] Epoxy resin is not a single pure compound, but a mixture of multiple molecular weights. It is a polycondensation product of epichlorohydrin and bisphenol (such as bisphenol A, bisphenol F, bisphenol S, etc.) or polyols. Due to different reaction temperatures, reaction times, proportions of materials involved in the reaction, and preparation methods, epoxy resins with different epoxy viscosities, epoxy equivalents, hydroxyl values, average molecular weights and molecular weight distribution melting points (solid resins), and thermal deformation temperatures of cured bodies can be produced. Therefore, the application conditions and application range of epoxy resins are wider. In addition, epoxy resins have excellent physical, mechanical and electrical insulation properties, bonding properties, and flexible use processes, which are irreplaceable by other thermosetting plastics. Therefore, it can be made into coatings, composite materials, casting materials, adhesives, molding materials, injection molding materials, etc., and has been widely used and promoted in various fields such as electronics, machinery, and engineering. At present, the main varieties of epoxy resins produced in my country include the following categories: (1) bisphenol A epoxy resin; (2) bisphenol F epoxy resin; (3) bisphenol S epoxy resin; (4) hydrogenated bisphenol A epoxy resin; (5) linear phenolic epoxy resin; (6) multifunctional glycidyl ether resin; (7) multifunctional glycidyl amine resin; (8) halogenated epoxy resin with special functions.

[0003] However, all of the above-mentioned epoxy resins have a unified hydrophobic property. Simply put, they cannot adhere to the surface with water. Therefore, when preparing and researching products for underwater applications (such as underwater epoxy adhesives, underwater epoxy repair adhesives, underwater epoxy repair mortars), underwater curing agents and additives with special properties are required, and they need to be selectively combined with epoxy resins to prepare functional materials with underwater curing operation capabilities, but the construction performance is poor. Currently, in order to improve the bonding performance of underwater epoxy adhesive products underwater, most research directions focus on researching underwater curing agents for epoxy resin curing, and there are no relevant research reports and patent publications on the adhesion of epoxy resins themselves to the surface of underwater substrates. Therefore, researching and producing epoxy resins that can adhere to the surfaces of various underwater substrates can effectively develop underwater epoxy application products, improve the various properties of underwater epoxy products, especially improve their bonding performance on the surface of underwater substrates. At the same time, it becomes very easy to configure and produce epoxy products with excellent underwater performance. It can further expand the application scope of epoxy resins, solve many problems existing in the construction, protection, maintenance, and repair of underwater buildings, and has far-reaching significance for the country's economic construction. Therefore, it is very necessary to research and solve the problem that epoxy resins themselves can have good adhesion properties on the surfaces of various underwater substrates, and it is also a frontier scientific and technological field in epoxy resin preparation.

[0004] Currently, there are the following problems: (1) Existing single-component epoxy resins do not have the performance of being able to break the water film on the surface of underwater substrates and effectively adhere to the surface of underwater substrates. (2) For existing single-component epoxy products, their flexibility, salt spray resistance, and bonding performance with the surface of underwater substrates are not ideal. (3) When configuring products with existing epoxy resins, to improve their comprehensive performance, several types of epoxy resins need to be compounded or modified to basically meet the design requirements of the products. Moreover, the configuration process and material ratio are complex, requiring a large amount of manpower and material resources, and the underwater construction performance is poor. Also, each time a type of epoxy resin is prepared, energy is consumed once, and the preparation of several types of epoxy resins consumes energy several times. The repeated consumption causes energy waste. And during the preparation process of each type of epoxy resin, some waste gas and wastewater are generated. For the preparation of several types of epoxy resins, the discharge of waste gas and wastewater is several times, which has a potential impact on the environment and is difficult to meet the requirements of modern green and environmental protection development. Summary of the Invention

[0005] The technical problem to be solved by this application is to propose a preparation method of silicon whisker copolymerized epoxy resin and silicon whisker copolymerized epoxy resin in view of the above deficiencies of the prior art.

[0006] A preparation method of silicon whisker copolymerized epoxy resin includes:

[0007] Step S100: Charge raw materials into the reactor, including bisphenol A, bisphenol F, 5,5-dimethylhydantoin, epichlorohydrin, and isopropanol, and heat and stir to dissolve and mix evenly; control the reaction temperature, and prepare a mixed epoxy resin of bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and hydantoin epoxy resin under the action of catalyst A;

[0008] Step S200: After the preparation of the mixed epoxy resin is completed, add a branching agent, silicon whiskers, and a coupling agent to the reactor; and control the reaction conditions, and dropwise add catalyst B to promote the branching reaction, so that the bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reactor undergo a branching coupling reaction to obtain silicon whisker copolymerized epoxy resin.

[0009] Optionally, step S100 specifically includes:

[0010] Step S101: Charge raw materials into the reactor, including bisphenol A, bisphenol F, 5,5-dimethylhydantoin, epichlorohydrin, and isopropanol, and heat and stir to dissolve and mix evenly;

[0011] Step S102: Control the reaction conditions, and dropwise add catalyst A to the reactor for the first time to generate a chlorohydrin ether intermediate in the reactor;

[0012] Step S103: After the generation of the chlorohydrin ether intermediate, stop dropping catalyst A, and carry out vacuum distillation to recover epichlorohydrin;

[0013] Step S104: After the recovery of epichlorohydrin is completed, dropwise add catalyst A to the reactor for the second time, control the temperature, and maintain the reaction until the preparation of the mixed resin including bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and hydantoin epoxy resin is completed.

[0014] Optionally, step S101 is specifically: Stir and heat up to 50°C - 70°C to dissolve and mix evenly the raw materials added to the reactor;

[0015] Step S102 is specifically: Continue to heat the reactor to 70°C - 90°C, maintain this temperature range, dropwise add catalyst A to the reactor for the first time, and react for 2 - 3 hours to prepare a chlorohydrin ether intermediate;

[0016] Step S103 is specifically: After the generation of the chlorohydrin ether intermediate, stop dropping catalyst A at this time, continue to maintain the temperature in the reactor at 70°C - 90°C, and carry out vacuum distillation to recover epichlorohydrin;

[0017] Step S104 specifically is: After the recovery of epichlorohydrin is completed, catalyst A is added dropwise to the reaction kettle for the second time, and the temperature is continuously maintained at 70°C - 90°C, and the reaction is carried out under normal pressure for 1 - 2 hours until the preparation of the mixed resin of bisphenol A epoxy resin, bisphenol F epoxy resin, and hydantoin epoxy resin is completed.

[0018] Optionally, the branching agent is polyether polyol or aliphatic polyol.

[0019] Optionally, step 200 includes:

[0020] Add the branching agent bisphenol A polyoxy polyether, silicon whiskers, and coupling agent to the reaction kettle; among them, bisphenol A polyoxy polyether is 10 - 20% of the entire reaction system, silicon whiskers are 1 - 5%, and the coupling agent is 0.1 - 1%;

[0021] Control the reaction conditions, raise the temperature in the reaction kettle to 120°C - 150°C, add catalyst B dropwise to promote the ring-opening grafting reaction between the epoxy group and the polyether hydroxyl group, and the reaction time is 1 - 2 hours, so that bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reaction kettle undergo grafting coupling to obtain a crude product of silicon whisker copolymerized epoxy resin.

[0022] Optionally, catalyst B is any one of imidazole catalysts, tertiary amine catalysts, and organometallic catalysts.

[0023] Optionally, it further includes the step: step S300, washing and filtering the silicon whisker copolymerized epoxy resin to remove the salt impurities in the reaction system to obtain purified silicon whisker copolymerized epoxy resin.

[0024] Optionally, step 300 includes:

[0025] Step S301, cool the temperature of the materials in the reaction kettle to room temperature, add water to wash away the generated sodium chloride and unreacted alkaline substances;

[0026] Step S302, separation and purification: Through filtration, decompression, distillation, and removal of the solvent, purified silicon whisker copolymerized epoxy resin is obtained.

[0027] Optionally, catalyst A is a 29% NaOH alkaline solution. The first dropwise addition of the NaOH alkaline solution is 66% of the total amount, and the second dropwise addition of the NaOH alkaline solution is 34% of the total amount. At the same time, after the first dropwise addition of the base is completed, epichlorohydrin is recovered.

[0028] Optionally, the respective raw materials and their corresponding mass parts are:

[0029] Bisphenol A, 40 - 80 parts;

[0030] Bisphenol F, 10 - 30 parts;

[0031] 5.5 - dimethylhydantoin, 10 - 30 parts;

[0032] Epichlorohydrin 110 - 120 parts;

[0033] Isopropanol, 10 - 20 parts;

[0034] Catalyst A (29% NaOH alkaline solution): 250 - 280 parts.

[0035] Optionally, the respective raw materials and corresponding parts by mass are:

[0036] Bisphenol A, 50 parts;

[0037] Bisphenol F, 30 parts;

[0038] 5.5 - dimethylhydantoin, 20 parts;

[0039] Epichlorohydrin, 115 parts;

[0040] Isopropanol, 15 parts;

[0041] Catalyst A (29% NaOH alkaline solution): 270 parts.

[0042] Optionally, bisphenol A polyoxy polyether is 10 - 20 parts of the whole reaction system, silicon whiskers are 2 - 7 parts, and coupling agent is 0.2 - 1 part.

[0043] On the other hand, the present application also provides a silicon whisker copolymerized epoxy resin, and the silicon whisker copolymerized epoxy resin is prepared by the above - mentioned preparation method.

[0044] The silicon whisker copolymerized epoxy resin prepared by the present application has certain hydrophobicity and hydrophilicity. It will not disperse during underwater construction, can break the water film on the surface of the underwater substrate, adhere to the surface of the underwater substrate, and obtain good adhesion. In addition, compared with conventional epoxy resins (for example, E44 epoxy resin, 128 epoxy resin), the silicon whisker copolymerized epoxy resin provided by the present application can improve the comprehensive performance of underwater epoxy products, mainly the adhesion performance of epoxy products to the substrate surface underwater, and plays a significant improvement role. In addition, the present application prepares several required epoxy resins in the reaction kettle at the same time, consuming less energy. For specific reference, see the description in the specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a flowchart of the preparation method of the silicon whisker copolymerized epoxy resin in the embodiment of the present application.

[0046] Figure 2 is another flowchart of the preparation method of the silicon whisker copolymerized epoxy resin in the embodiment of the present application.

[0047] Figure 3 It is another flow chart of the preparation method of the swelling silicon whisker copolymerized epoxy resin in the embodiments of the present application.

[0048] Figure 4 It is another flow chart of the preparation method of the silicon whisker copolymerized epoxy resin in the embodiments of the present application. Specific Embodiments

[0049] The following are specific embodiments of the present application. In combination with the accompanying drawings, the technical solutions of the present application will be further described, but the present application is not limited to these embodiments. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present application. Therefore, those skilled in the art should clearly understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, descriptions of known functions and configurations are omitted for clarity and conciseness.

[0050] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0051] The embodiments of the present application provide a preparation method of a silicon whisker copolymerized epoxy resin, and a silicon whisker copolymerized epoxy resin prepared by using the preparation method. The silicon whisker copolymerized epoxy resin can break the water film on the surface of the underwater substrate, and the preparation and preparation method of the epoxy resin with good adhesion performance can improve the various performances of underwater epoxy products, mainly the bonding performance between the epoxy products and the substrate surface underwater, and play a significant improvement role.

[0052] Figure 1 A flow chart of a preparation method of a silicon whisker copolymerized epoxy resin is shown. The preparation method at least includes step S100-step S200.

[0053] In step S100, raw materials including bisphenol A, bisphenol F, 5,5-dimethylhydantoin, epichlorohydrin, and isopropanol are put into a reaction kettle, heated and stirred to dissolve, and mixed evenly; the reaction temperature is controlled, and a mixed epoxy resin of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and hydantoin epoxy resin is prepared under the action of catalyst A.

[0054] In step S200, after the mixed epoxy resin is prepared, a branching agent, silicon whiskers, and a coupling agent are added to the reaction kettle; and the reaction conditions are controlled, and catalyst B is added dropwise to promote the branching reaction, so that the bisphenol A type epoxy resin, bisphenol F type epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reaction kettle carry out a branching coupling reaction to obtain a silicon whisker copolymerized epoxy resin.

[0055] In an embodiment of the present application, step S100 specifically includes step S101-step S104.

[0056] Step S101: Charge raw materials into the reaction kettle, including bisphenol A, bisphenol F, 5,5-dimethylhydantoin, epichlorohydrin, and isopropanol, and heat and stir to dissolve and mix evenly.

[0057] Step S102: Control the reaction conditions and add catalyst A dropwise to the reaction kettle for the first time to generate a chlorohydrin ether intermediate in the reaction kettle.

[0058] Step S103: After the chlorohydrin ether intermediate is generated, stop adding catalyst A dropwise, carry out vacuum distillation, and recover epichlorohydrin.

[0059] Step S104: After the recovery of epichlorohydrin is completed, add catalyst A dropwise to the reaction kettle for the second time, control the temperature, and maintain the reaction until a mixed resin including bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and hydantoin epoxy resin is prepared. For the prepared mixed resin, the epoxy value is controlled between 0.40 and 0.50 eq / 100g, and the organic chlorine is ≤ 0.1%.

[0060] For further reference Figure 2 Step S101 specifically is: Stir and heat up to 50°C - 70°C to dissolve and mix evenly the raw materials added to the reaction kettle.

[0061] Step S102 specifically is: Continue to heat up the reaction kettle to 70°C - 90°C, maintain this temperature range, add catalyst A dropwise to the reaction kettle for the first time, and react for 2 - 3 hours to prepare a chlorohydrin ether intermediate.

[0062] Step S103 specifically is: After the chlorohydrin ether intermediate is generated, stop adding catalyst A dropwise at this time, continue to maintain the temperature in the reaction kettle at 70°C - 90°C, and carry out vacuum distillation to recover epichlorohydrin.

[0063] Step S104 specifically is: After the recovery of epichlorohydrin is completed, add catalyst A dropwise to the reaction kettle for the second time, continue to maintain the temperature at 70°C - 90°C, maintain the reaction under normal pressure for 1 - 2 hours until a mixed resin of bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and hydantoin epoxy resin is prepared.

[0064] In steps S101 - S104, catalyst A is a 29% NaOH alkaline solution. The first addition of the NaOH alkaline solution is 66% of the total amount, and the second addition is 34% of the total amount. Meanwhile, after the first addition of the alkali is completed, epichlorohydrin is recovered. It should be noted that the main role of epichlorohydrin is to react with bisphenol A, bisphenol F, and 5,5 - dimethylhydantoin under the action of a catalyst to form a chlorohydrin ether intermediate. In this reaction stage, epichlorohydrin and the alkali act alternately. In the subsequent resin synthesis stage, the excess epichlorohydrin no longer participates in useful reactions. Also, in the pre - reaction stage, no epoxy resin is produced, the viscosity of the reaction system is low, and it is much easier to recover epichlorohydrin compared to the final stage of the reaction, and waste is reduced. Therefore, it is very ideal and cost - saving to recover epichlorohydrin in the middle of the entire preparation process.

[0065] Reference Figure 3 , in the embodiment of the present application, step 200 includes: adding a branching agent, bisphenol A polyoxy polyether, silicon whiskers, and a coupling agent to a reaction kettle; wherein, bisphenol A polyoxy polyether accounts for 10 - 20% of the entire reaction system, silicon whiskers account for 1 - 5%, and the coupling agent accounts for 0.1 - 1%; controlling the reaction conditions, raising the temperature in the reaction kettle to 120°C - 150°C, and adding catalyst B dropwise to promote the ring - opening grafting reaction between epoxy groups and polyether hydroxyl groups. The reaction time is 1 - 2 hours, so that bisphenol A - type epoxy resin, bisphenol F - type epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reaction kettle undergo grafting coupling to obtain a crude product of silicon whisker copolymerized epoxy resin.

[0066] Specifically, in step S200, in the branching reaction, the epoxy groups in the mixed epoxy resin react with the hydroxyl groups in bisphenol A polyoxy polyether to form new C - O - C bonds and generate a branched structure. Moreover, multiple epoxy groups and hydroxyl groups react alternately to form a functional resin with a branched structure - a crude product of silicon whisker copolymerized epoxy resin.

[0067] The branching agent in the preparation of the above - mentioned silicon whisker copolymerized epoxy resin can be polyether polyol or aliphatic polyol, and specifically bisphenol A polyoxy polyether is used.

[0068] Further, catalyst B is any one of imidazole - type catalysts, tertiary amine - type catalysts, and organometallic catalysts. In a specific technical solution, catalyst B can be selected as a quaternary ammonium salt catalyst - tetrabutylammonium bromide.

[0069] The method for preparing silicon whisker copolymerized epoxy resin provided by the embodiment of the present application further includes the step: step S300, washing and filtering the silicon whisker copolymerized epoxy resin to remove salt impurities in the reaction system, and obtaining purified silicon whisker copolymerized epoxy resin.

[0070] Further, referring to Figure 3 , step 300 includes: step S301 and step S302.

[0071] In step S301, the temperature of the materials in the reaction kettle is cooled to room temperature, and water washing is carried out to remove the generated sodium chloride and unreacted basic substances.

[0072] In step S302, separation and purification: through filtration, reduced pressure, distillation, and removal of the solvent, purified silicon whisker copolymerized epoxy resin is obtained.

[0073] It should be understood that the above preparation method of silicon whisker copolymerized epoxy resin involves step S100-step S300, Figure 4 and the flow chart shown includes step S100-step S300.

[0074] In the embodiments of the present application, the respective raw materials and corresponding parts by mass are: bisphenol A, 40-80 parts; bisphenol F, 10-30 parts; 5,5-dimethylhydantoin, 10-30 parts; epichlorohydrin, 110-120 parts; isopropanol, 10-20 parts; catalyst A (29% NaOH alkaline solution): 250-280 parts. Further, the respective raw materials and corresponding parts by mass are specifically: bisphenol A, 50 parts; bisphenol F, 30 parts; 5,5-dimethylhydantoin, 20 parts; epichlorohydrin, 115 parts; isopropanol, 15 parts; catalyst A (29% NaOH alkaline solution): 270 parts.

[0075] In addition, in step S200, bisphenol A polyoxy polyether is 10-20 parts of the whole reaction system, silicon whiskers are 2-7 parts, and the coupling agent is 0.2 part - 1 part. Further, bisphenol A polyoxy polyether is 15 parts of the whole reaction system, silicon whiskers are 3 parts, and the coupling agent is 0.5 part.

[0076] Example 1

[0077] The respective raw materials and corresponding parts by mass are: bisphenol A, 40-80 parts; bisphenol F, 10-30 parts; 5,5-dimethylhydantoin, 10-30 parts; epichlorohydrin, 110-120 parts; isopropanol, 10-20 parts; NaOH (29% aqueous solution), 250-280 parts; bisphenol A polyoxy polyether, 10-20 parts; silicon whiskers, 2-7 parts; coupling agent, 0.2 part - 1 part; tetraalkyl quaternary ammonium salt, 100 parts - 120 parts (30% aqueous solution).

[0078] In this embodiment, the respective raw materials and corresponding parts by mass are:

[0079] The first group of materials

[0080] Bisphenol A, 50 parts;

[0081] Bisphenol F, 30 parts;

[0082] 5,5 - Dimethylhydantoin, 20 parts;

[0083] Epichlorohydrin, 115 parts;

[0084] Isopropanol, 15 parts;

[0085] NaOH (29% aqueous solution), 178 parts (66% added for the first time in the pre - reaction stage);

[0086] NaOH (29% aqueous solution), 92 parts (34% added for the second time in the post - reaction stage).

[0087] The second group of materials

[0088] Bisphenol A polyoxy polyether, 15 parts;

[0089] Silicon whiskers, 3 parts;

[0090] Coupling agent, 0.5 part;

[0091] Tetraalkyl quaternary ammonium salt, 110 parts (30% aqueous solution)

[0092] Catalyst A is NaOH (29% aqueous solution).

[0093] Specifically, the first step: Weigh accurately 50 parts of bisphenol A, 30 parts of bisphenol F, 20 parts of 5,5 - dimethylhydantoin and other materials and add them to a stirring reaction kettle. Stir and heat up to 50°C - 70°C to fully dissolve the raw materials in the reaction kettle and stir evenly. Continue to heat up the reaction kettle. When the temperature reaches 70°C, fill it with nitrogen. Under nitrogen protection, dropwise add 178 parts of NaOH (29% aqueous solution) catalyst, control the temperature between 70°C - 90°C, and maintain the reaction for 1.5 hours. At this time, carry out vacuum distillation to recover epichlorohydrin. Continue to dropwise add NaOH (29% aqueous solution), control the temperature between 70°C - 90°C, and maintain the reaction for 1 hour to generate a mixed solution of bisphenol A - type epoxy resin, bisphenol F - type epoxy resin, and hydantoin epoxy resin.

[0094] The second step: Weigh accurately and put 15 parts of bisphenol A polyoxy polyether, 3 parts of silicon whiskers, 0.5 part of coupling agent and other raw materials into the reaction kettle, and stir evenly. Raise the temperature to 120°C, and start to dropwise add 110 parts of quaternary ammonium salt catalyst B, tetraalkyl quaternary ammonium salt, to promote the branching reaction, and maintain the reaction time for 1 hour to carry out graft coupling of bisphenol A - type epoxy resin, bisphenol F - type epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reaction kettle to obtain a crude product of silicon whisker copolymerized epoxy resin.

[0095] Third step: Cool the materials in the reactor to room temperature, add water to wash away the generated sodium chloride and unreacted alkaline substances; Separation and purification: Obtain purified silicon whisker copolymerized epoxy resin by filtration, decompression, distillation, and removal of the solvent.

[0096] Example 2

[0097] The respective raw materials and corresponding parts by mass are as follows: bisphenol A, 40 - 80 parts; bisphenol F, 10 - 30 parts; 5,5 - dimethylhydantoin, 10 - 30 parts; epichlorohydrin, 110 - 120 parts; isopropanol, 10 - 20 parts; NaOH (29% aqueous solution), 250 - 280 parts; bisphenol A polyoxy polyether, 10 - 20 parts; silicon whiskers, 2 - 7 parts; coupling agent, 0.2 - 1 part; tetraalkyl quaternary ammonium salt, 100 - 120 parts (30% aqueous solution).

[0098] In this example, the respective raw materials and corresponding parts by mass are:

[0099] The first group of materials

[0100] Bisphenol A, 30 parts;

[0101] Bisphenol F, 50 parts;

[0102] 5,5 - dimethylhydantoin, 20 parts;

[0103] Epichlorohydrin, 120 parts;

[0104] Isopropanol, 20 parts;

[0105] NaOH (29% aqueous solution), 178 parts (66% added for the first time in the pre - reaction stage);

[0106] NaOH (29% aqueous solution) 92 parts (34% added for the first time in the post - reaction stage).

[0107] The second group of materials

[0108] Bisphenol A polyoxy polyether, 20 parts;

[0109] Silicon whiskers, 5 parts;

[0110] Coupling agent, 0.7 part;

[0111] Tetraalkyl quaternary ammonium salt, 110 parts (30% aqueous solution);

[0112] Specifically, the first step: accurately weigh 30 parts of bisphenol A, 50 parts of bisphenol F, 20 parts of 5,5-dimethylhydantoin and other materials, add them to a stirring reaction kettle, stir and heat up to 50°C - 70°C to fully dissolve the raw materials in the reaction kettle and stir evenly; continue to heat up the reaction kettle, when the temperature reaches 70°C, fill it with nitrogen, and under the protection of nitrogen, dropwise add 178 parts of NaOH (29% aqueous solution) catalyst, control the temperature between 70°C - 90°C, and maintain the reaction for 1.5 hours; at this time, carry out vacuum distillation to recover epichlorohydrin; continue to dropwise add 92 parts of NaOH (29% aqueous solution), control the temperature between 70°C - 90°C, and maintain the reaction for 1 hour to generate a mixed solution of bisphenol A epoxy resin, bisphenol F epoxy resin, and hydantoin epoxy resin.

[0113] The second step: accurately weigh and put 20 parts of bisphenol A polyoxy polyether, 5 parts of silicon whiskers, 0.7 part of coupling agent and other raw materials into the reaction kettle, and stir evenly; raise the temperature to 120°C, start to dropwise add 110 parts of quaternary ammonium salt catalyst B - tetraalkyl quaternary ammonium salt to promote the branching reaction, maintain the reaction time for 1 hour, and carry out graft coupling of bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin, and silicon whiskers generated in the reaction kettle to obtain a crude product of silicon whisker copolymerized epoxy resin.

[0114] The third step: cool the temperature of the materials in the reaction kettle to room temperature, add water to wash away the generated sodium chloride and unreacted alkaline substances; separate and purify: through filtration, vacuum, distillation, and remove the solvent to obtain purified silicon whisker copolymerized epoxy resin.

[0115] In the embodiment of the present application, the main chemical reaction formulas for the generation of the mixed resin are as follows:

[0116] ⑴ Chemical reaction formula for the generation of bisphenol A epoxy resin

[0117] Chemical reaction expression for the generation of bisphenol A epoxy resin from bisphenol A and epichlorohydrin in the presence of an alkaline catalyst (such as sodium hydroxide):

[0118] ① Addition reaction (generating a chlorohydrin ether intermediate):

[0119] C6H4(OH)2(C(CH3)2)+2C3H5C l O→C6H4(OCH2CH(OH)CH2)2(C(CH3)2)+2HCl;

[0120] ② Cyclization reaction (generating bisphenol A epoxy resin): C6H4(OCH2CH(OH)CH2)2(C(CH3)2)+2NaOH→C6H4(OCH2CH(O)CH2)2(C(CH3)2)+2NaC l+2H2O;

[0121] ⑵ Chemical reaction formula for the generation of hydantoin epoxy resin

[0122] 5,5 - dimethylhydantoin reacts with epichlorohydrin in the presence of a basic catalyst (such as sodium hydroxide) to form hydantoin epoxy resin. Its chemical reaction is divided into two main stages:

[0123] ① Addition reaction (formation of chlorohydrin intermediate):

[0124] C5H6N2O2 + 2C3H5ClO → C5H4(N(CH2CH(OH)CH2)N)(C(CH3)2) + 2HCl;

[0125] ② Cyclization reaction (formation of hydantoin epoxy resin): C5H4(N(CH2CH(OH)CH2)N)(C(CH3)2) + 2NaOH → C5H4(N(CH2CH(O)CH2)N)(C(CH3)2) + 2NaCl + 2H2O;

[0126] ⑶ Chemical reaction formula for the formation of bisphenol F epoxy resin

[0127] Bisphenol F reacts with epichlorohydrin in the presence of a basic catalyst (such as sodium hydroxide) to form bisphenol F epoxy resin; its chemical reaction is similar to that of bisphenol A epoxy resin, but the reactant is bisphenol F, and its molecular structure is: C6H4(OH)-CH2-C6H4(OH);

[0128] ① Addition reaction (formation of chlorohydrin ether intermediate): C6H4(OH)-CH2-C6H4(OH) + 2C3H5ClO → C6H4(OCH2CH(OH)CH2)-CH2-C6H4(OCH2CH(OH)CH2) + 2HCl;

[0129] ② Cyclization reaction (formation of epoxy resin):

[0130] C6H4(OCH2CH(OH)CH2)-CH2-C6H4(OCH2CH(OH)CH2) + 2HCl + 2NaOH → C6H4(OCH2CH(O)CH2)-CH2-C6H4(OCH2CH(O)CH2) + 2NaCl + 2H2O;

[0131] ⑷ The complete chemical reaction of the branching reaction of mixed resins such as bisphenol A epoxy resin, hydantoin epoxy resin, and bisphenol F epoxy resin with bisphenol A polyoxy polyether and silane coupling agent to form silicon whisker copolymer epoxy resin is relatively complex, involving ring-opening reactions of epoxy resins, copolymerization with bisphenol A polyoxy polyether, hydrolysis and condensation of silane coupling agents, and other reaction and structural steps; the main chemical reaction formula for the formed silicon whisker copolymer epoxy resin is summarized as:

[0132] R1-(Epoxy)+R2-(Polyether)+R3-Si(OEt)3+H2O→R1-(Epoxy)-R2-(Polyether)-R3-Si-O-Si-network;

[0133] Wherein:

[0134] R1 represents the mixed epoxy resin skeleton, such as bisphenol A, bisphenol F, and hydantoin structure;

[0135] R2 is the structure of bisphenol A polyoxy polyether;

[0136] R3 represents the organic part of the silane coupling agent.

[0137] An embodiment of the present application also provides a silicon whisker copolymerized epoxy resin, and the silicon whisker copolymerized epoxy resin is prepared by the above preparation method.

[0138] The silicon whisker copolymerized epoxy resin prepared in the present application has certain hydrophobicity and hydrophilicity. The surface energy on the surface of the underwater substrate can break the water film, attach to the surface of the underwater substrate, and obtain good adhesion. In addition, compared with conventional epoxy resins (for example, E44 epoxy resin, 128 epoxy resin), the silicon whisker copolymerized epoxy resin provided in the present application can improve the various properties of underwater epoxy products, mainly the adhesion performance between the epoxy products and the substrate surface underwater, which plays a significant improvement role.

[0139] According to the test standards for bond strength and compressive strength: "Test Methods for Properties of Resin Castings" GB / T 2567-2021, "Epoxy Resin Grouting Materials for Foundation and Foundation Treatment" JC / T 2379-2016, "Test Methods for the Strength of Cement Mortar (ISO Method)" GB / T 17671-2021, the underwater adhesives and underwater anti-abrasion coatings prepared with the silicon whisker copolymerized epoxy resin and underwater curing agent provided in the present application are tested, and the bond strength is above 3.4 MPa, and the compressive strength is above 50 MPa.

[0140] Comparison of the main properties between the silicon whisker copolymerized epoxy resin prepared in the present application and conventional epoxy resins (for example, E44 epoxy resin, 128 epoxy resin):

[0141] (1) Underwater adhesion: The silicon whisker copolymerized epoxy resin can break the water film on the surface of the underwater substrate and attach to the surface of the underwater substrate; conventional epoxy resins cannot attach to the surface of the substrate with water at all.

[0142] (2) Underwater bonding performance: The underwater adhesive prepared with silicon whisker copolymerized epoxy resin and underwater curing agent 8410 (underwater curing agent 8410 is the best underwater epoxy curing agent currently) is used for the specimens bonded by underwater eight-shaped molds. The bonding strength is ≥3.4 MPa, the highest is >5 MPa, and generally it is between 4 - 5 MPa. However, for the specimens of the eight-shaped molds bonded by conventional epoxy resin and underwater curing agent 8410 underwater, only the bonding strength ≥1.5 MPa is satisfied.

[0143] (3) Flexibility: ⑴ For the underwater adhesive prepared with silicon whisker copolymerized epoxy resin and underwater curing agent 8410, its compressive strength is ≥50 MPa, but the compression specimens are not damaged and can recover in a short time, indicating that the flexibility of its cured body is very good; although the compressive strength of underwater curing agent 8410 and conventional epoxy resin is ≥60 MPa, the specimens will break after the compression test, indicating that the cured material is very brittle. ⑵ The underwater adhesive prepared with silicon whisker copolymerized epoxy resin and underwater curing agent 8410 can be cast into a 2-mm-thick sheet, which can be rolled into a Φ50-mm circle and can be repeated without cracks; however, for the underwater adhesive prepared with underwater curing agent 8410 and conventional epoxy resin, when cast into a 2-mm-thick sheet, it will break as long as it is bent.

[0144] (4) Workability: The underwater coating prepared with silicon whisker copolymerized epoxy resin and underwater curing agent 8410 has good coating performance on the underwater substrate surface, without dispersion, blistering or peeling; while the coating prepared with underwater curing agent 8410 and conventional epoxy resin has poor coating performance on the underwater substrate surface and disperses and floats.

[0145] (5) All underwater products prepared with silicon whisker copolymerized epoxy resin and underwater curing agent 8410 are pollution-free to water quality. Some grades of conventional epoxy resin cannot be used in drinking water pools.

[0146] (6) The conventional coating prepared with silicon whisker copolymerized epoxy resin is resistant to ultraviolet irradiation, while conventional epoxy resin is not.

[0147] The silicon whisker copolymerized epoxy resin prepared in this application has certain hydrophobicity and hydrophilicity. It will not disperse during underwater construction, can break the water film on the underwater substrate surface, adhere to the underwater substrate surface, and obtain good bonding performance. In addition, compared with conventional epoxy resins (for example, E44 epoxy resin, 128 epoxy resin), the silicon whisker copolymerized epoxy resin provided in this application can improve the comprehensive performance of underwater epoxy products, mainly the bonding performance between epoxy products and the substrate surface underwater, and plays a significant improvement role.

[0148] In addition, it should be understood that by using the solutions of the prior art, bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin, silicon whiskers and the branching agent bisphenol A polyoxy polyether can be directly added into the reaction kettle for grafting and coupling reaction, and silicon whisker copolymerized epoxy resin can also be obtained, but the preparation cost is high and energy is wasted. In this application, several required epoxy resins are prepared simultaneously in the reaction kettle, and the energy consumption is less.

[0149] In the above embodiments of the present application, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0150] In the above embodiments of the present application, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0151] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined. It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0152] The specific embodiments described herein are merely illustrative of the technical solutions of the present application. Those skilled in the art to which the present application pertains can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, but will not deviate from the scope defined by the claims of the present application.

Claims

1. A method for preparing a silicon whisker copolymer epoxy resin, characterized in that: include: Step S100, putting raw materials including bisphenol A, bisphenol F, 5.5 dimethyl hydantoin, epichlorohydrin, and isopropyl alcohol into a reaction kettle, and heating and stirring to dissolve and mix evenly; controlling the reaction temperature, and preparing a mixed epoxy resin of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and hydantoin epoxy resin under the action of catalyst A; Step S200, after the mixed epoxy resin is prepared, a branching agent, silicon whiskers, and a coupling agent are added to the reactor; and the reaction conditions are controlled, and a catalyst B is added dropwise to promote a branching reaction, so that the bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin, and silicon whiskers in the reactor undergo a branching and coupling reaction to obtain a silicon whisker copolymerized epoxy resin.

2. The preparation method of silicon whisker copolymer epoxy resin according to claim 1, wherein Step S100 specifically includes: Step S101, adding raw materials including bisphenol A, bisphenol F, 5.5 dimethyl hydantoin, epichlorohydrin, and isopropyl alcohol into a reaction kettle, and heating and stirring to dissolve and mix evenly; Step S102, controlling the reaction conditions, and adding catalyst A to the reactor for the first time to generate a chlorohydrin ether intermediate in the reactor; Step S103, when the chlorohydrin ether intermediate is generated, stop adding the catalyst A, and perform vacuum distillation to recover epichlorohydrin; Step S104: After the recovery of epichlorohydrin is completed, catalyst A is added dropwise to the reactor for the second time, the temperature is controlled, and the reaction is maintained until the mixed resin including bisphenol A epoxy resin, bisphenol F epoxy resin, and hydantoin epoxy resin is prepared.

3. The preparation method of silicon whisker copolymer epoxy resin according to claim 2, characterized in that, Step S101 specifically includes: stirring and heating to 50°C-70°C to dissolve and evenly mix the raw materials added to the reactor; Step S102 specifically comprises: continuing to heat the reactor to 70° C.-90° C., maintaining this temperature range, dripping catalyst A into the reactor for the first time, and reacting for 2-3 hours to prepare a chlorohydrin ether intermediate; Step S103 specifically includes: when the chlorohydrin ether intermediate is generated, the dropwise addition of catalyst A is stopped, the temperature in the reactor is maintained at 70° C.-90° C., and the epichlorohydrin is recovered by distillation under reduced pressure; Step S104 is specifically as follows: after the recovery of epichlorohydrin is completed, catalyst A is added dropwise to the reactor for the second time, the temperature continues to be maintained at 70°C-90°C, and the reaction is maintained at normal pressure for 1-2 hours until the mixed resin of bisphenol A epoxy resin, bisphenol F epoxy resin and hydantoin epoxy resin is prepared.

4. The preparation method of silicon whisker copolymer epoxy resin according to claim 1, wherein The branching agent is polyether polyol or aliphatic polyol.

5. The preparation method of silicon whisker copolymer epoxy resin according to claim 4, characterized in that, Step 200 includes: Add branching agent bisphenol A polyoxyethylene, silicon whiskers and coupling agent into the reaction kettle; wherein bisphenol A polyoxyethylene accounts for 10-20% of the entire reaction system, silicon whiskers account for 1-5%, and coupling agent accounts for 0.1-1%; The reaction conditions are controlled, the temperature in the reactor is raised to 120° C.-150° C., and catalyst B is added dropwise to promote a ring-opening grafting reaction between epoxy groups and polyether hydroxyl groups. The reaction time is 1-2 hours, so that the bisphenol A epoxy resin, bisphenol F epoxy resin, hydantoin epoxy resin and silicon whiskers in the reactor are graft-coupled to obtain a crude silicon whisker copolymerized epoxy resin.

6. The method for preparing a silicon whisker copolymer epoxy resin according to claim 1, wherein Catalyst B is any one of an imidazole catalyst, a tertiary amine catalyst, and an organic metal catalyst.

7. The method for preparing a silicon whisker copolymer epoxy resin according to claim 1, wherein The method further comprises the following steps: Step S300, washing and filtering the silicon whisker copolymerized epoxy resin to remove salt impurities in the reaction system, and obtaining a purified silicon whisker copolymerized epoxy resin.

8. The method for preparing a silicon whisker copolymer epoxy resin according to claim 7, wherein: Step 300 includes: Step S301, cooling the temperature of the materials in the reactor to room temperature, adding water to wash and remove the generated sodium chloride and unreacted alkaline substances; Step S302, separation and purification: obtaining purified silicon whisker copolymerized epoxy resin by filtering, reducing pressure, distilling, and removing solvent.

9. The method for preparing a silicon whisker copolymer epoxy resin according to claim 2, wherein: Catalyst A is a 29% NaOH alkaline solution. The first drop of NaOH alkaline solution is 66% of the total amount, and the second drop of NaOH alkaline solution is 34% of the total amount. After the first drop of alkali is completed, epichlorohydrin is recovered.

10. The method for preparing the silicon whisker copolymerized epoxy resin according to any one of claims 1 to 9, characterized in that: The raw materials and their corresponding mass parts are: Bisphenol A, 40-80 parts; Bisphenol F, 10-30 parts; 5.5 dimethyl hydantoin, 10-30 parts; Epichlorohydrin 110-120 parts; Isopropyl alcohol, 10-20 parts; Catalyst A (29% NaOH alkaline solution): 250-280 parts.

11. The method for preparing a silicon whisker copolymerized epoxy resin according to claim 10, wherein: The raw materials and their corresponding mass parts are: Bisphenol A, 50 parts; Bisphenol F, 30 parts; 5.5 dimethyl hydantoin, 20 parts; Epichlorohydrin, 115 parts; Isopropyl alcohol, 15 parts; Catalyst A (29% NaOH alkaline solution): 270 parts.

12. The method for preparing the silicon whisker copolymer epoxy resin according to claim 5, wherein: The bisphenol A polyoxyethylene polyether accounts for 10-20 parts of the entire reaction system, the silicon whisker accounts for 2-7 parts, and the coupling agent accounts for 0.2 parts to 1 part.

13. A silicon whisker copolymer epoxy resin, characterized in that: The silicon whisker copolymerized epoxy resin is prepared by the preparation method according to any one of claims 1 to 12.

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