Modified waterborne epoxy resin

Abstract

The invention provides modified water-borne epoxy resin, which is prepared from the following raw materials in parts by weight: 100 parts of bisphenol A epoxy resin, 15 to 45 parts of epoxy group silane coupling agents, 25 to 41 parts of polyacrylic acid substances, 100 to 170 parts of amino modified silicone oil and 65 to 80 parts of solvents, the preparation method comprises the following steps: adding 1-6 parts of a first catalyst, 1-5 parts of a second catalyst and 1-5 parts of a third catalyst, bonding a siloxane group of an epoxy group silane coupling agent with a secondary hydroxyl group of bisphenol A epoxy resin, and carrying out a ring-opening reaction on a carboxyl group of a polyacrylic acid substance and an epoxy group of the grafted epoxy group silane coupling agent to obtain a grafted epoxy group silane coupling agent; the amino group of the amino modified silicone oil and the epoxy group of the bisphenol A epoxy resin are subjected to ring-opening reaction. According to the modified epoxy resin provided by the invention, through the synergistic effect of the bisphenol A epoxy resin, the epoxy silane coupling agent, the polyacrylic acid substance and the modified silicone oil, a cured film of the modified epoxy resin can have relatively good hardness, toughness, water resistance and corrosion resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin modification, and particularly relates to a modified waterborne epoxy resin. BACKGROUND

[0002] At present, the waterborne epoxy resin still has some defects after being cured into a film, for example, (1) insufficient toughness, which is prone to cracking due to internal stress; (2) poor moisture resistance and corrosion resistance; and (3) poor hardness, thereby resulting in poor wear resistance. The above defects limit the use of the waterborne epoxy resin outdoors. SUMMARY

[0003] In order to overcome the deficiencies of the prior art, the purpose of the present application is to provide a modified waterborne epoxy resin, which, through the synergistic effect of bisphenol A epoxy resin, epoxy-based silane coupling agent, polyacrylic substance and modified silicone oil, can make the cured film of the modified epoxy resin have good hardness, toughness, water resistance and corrosion resistance.

[0004] To solve the above problems, the technical scheme adopted by the present application is as follows: A modified waterborne epoxy resin, by weight, the raw materials of the modified waterborne epoxy resin include: 100 parts of bisphenol A epoxy resin, 15-45 parts of epoxy-based silane coupling agent, 25-41 parts of polyacrylic substance, 100-170 parts of amino-modified silicone oil, 65-80 parts of solvent, 1-6 parts of first catalyst, 1-5 parts of second catalyst and 1-5 parts of third catalyst. The siloxane group of the epoxy-based silane coupling agent is bonded to the secondary hydroxyl group of the bisphenol A epoxy resin, the carboxyl group of the polyacrylic substance is ring-opening reacted with the epoxy group of the grafted epoxy-based silane coupling agent, the polyacrylic substance is at least one of polyacrylic acid and polyalkyl acrylic acid, the amino group of the amino-modified silicone oil is ring-opening reacted with the epoxy group of the bisphenol A epoxy resin, the first catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the amino-modified silicone oil, the second catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the epoxy-based silane coupling agent, and the third catalyst is used to catalyze the grafted epoxy-based silane coupling agent and the polyacrylic substance.

[0005] In some possible implementation manners, the epoxy-based silane coupling agent is selected from gamma-glycidoxypropyltrimethoxysilane or 2-(3,4-epoxycyclohexyl) ethyl triethoxysilane coupling agent.

[0006] In some possible implementation manners, the polyacrylic substance is selected from polymethyl acrylic acid.

[0007] In some possible implementation manners, the modified group of the amino-modified silicone oil is an end amino group.

[0008] In some possible embodiments, the amino-modified silicone oil is selected from amino-terminated polydimethylsiloxane.

[0009] In some possible embodiments, the amino silane coupling agent is in a proportion of 20-35 parts by weight, the polyacrylic substance is in a proportion of 27-37 parts by weight, and the amino-modified silicone oil is in a proportion of 110-150 parts by weight.

[0010] In some possible embodiments, the bisphenol A epoxy resin: the amino silane coupling agent: the polyacrylic substance is in a proportion of 20:5-6:6-7 by weight.

[0011] In some possible embodiments, the bisphenol A epoxy resin: the amino-modified silicone oil is in a proportion of 5:6-7 by weight.

[0012] In some possible embodiments, the first catalyst is selected from dibutyltin dilaurate, the second catalyst is selected from alkyl titanate catalysts, and the third catalyst is selected from tertiary amine catalysts.

[0013] In some possible embodiments, the modified waterborne epoxy resin is prepared by the following steps: The bisphenol A epoxy resin is dissolved in a solvent, stirred, and heated to 110-130°C, then the amino-modified silicone oil and the first catalyst are added for reaction, the reaction temperature is 110-130°C, and the reaction time is 4-6 hours; The stirring is maintained and the temperature is lowered to 30-50°C, then the epoxy-based silane coupling agent and the second catalyst are added for reaction, the reaction temperature is 35-50°C, and the reaction time is 3-5 hours; The stirring is maintained and the temperature is raised to 80-120°C, then the polyacrylic substance and the third catalyst are added for reaction, the reaction temperature is 100-130°C, and the reaction time is 3-4 hours.

[0014] Compared with the prior art, the present application has the following advantages: In the present application, by introducing the epoxy-based silane coupling agent and the polyacrylic substance into the bisphenol A epoxy resin, a crosslinked structure can be formed on one side of the repeating unit of the epoxy resin, thereby facilitating the improvement of the hardness of the cured film of the modified epoxy resin. In addition, by grafting the acrylic substance with the coupling agent, the synergistic effect of the coupling agent and the polyacrylic substance on flexibility can be exerted, thereby avoiding excessive rigidity of the epoxy resin. Furthermore, the introduction of the silicone oil substance into the main chain can synergistically exert its flexibility, water resistance, and corrosion resistance. Therefore, through the synergistic effect of the bisphenol A epoxy resin, the epoxy-based silane coupling agent, the polyacrylic substance, and the modified silicone oil, the cured film of the modified epoxy resin can have good hardness, flexibility, water resistance, and corrosion resistance. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of the present application.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0017] Some embodiments of the present application will be described in detail below. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0018] An embodiment of the present application provides a modified waterborne epoxy resin. Raw materials of the modified waterborne epoxy resin include, by weight parts, 100 parts of bisphenol A epoxy resin, 15-45 parts of epoxy-based silane coupling agent, 25-41 parts of polyacrylic substance, 100-170 parts of amino-modified silicone oil, 65-80 parts of solvent, 1-6 parts of first catalyst, 1-5 parts of second catalyst and 1-5 parts of third catalyst. Exemplarily, the solvent can be at least one of benzene and toluene. A siloxane group of the epoxy-based silane coupling agent is bonded with a secondary hydroxyl group of the bisphenol A epoxy resin, so as to realize epoxy resin grafting. A carboxyl group of the polyacrylic substance is ring-opening reacted with an epoxy group of the grafted epoxy-based silane coupling agent, so as to realize crosslinking of the polyacrylic substance and the epoxy resin. The polyacrylic substance is at least one of polyacrylic acid and polyalkyl acrylic acid. An amino group of the amino-modified silicone oil is ring-opening reacted with an epoxy group of the bisphenol A epoxy resin. The first catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the amino-modified silicone oil, the second catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the epoxy-based silane coupling agent, and the third catalyst is used to catalyze the grafted epoxy-based silane coupling agent and the polyacrylic substance.

[0019] In the present application, by introducing an epoxy-based silane coupling agent and a polyacrylic substance on the bisphenol A epoxy resin, a cross-linked structure can be formed on one side of the repeating unit of the epoxy resin, thereby facilitating the improvement of the hardness of the modified epoxy resin cured film. In addition, by grafting the acrylic substance with the coupling agent, the synergistic effect of the coupling agent and the polyacrylic substance on flexibility can also be exerted, thereby avoiding excessive rigidity of the epoxy resin. In addition, the introduction of silicone oil substances on the main chain can synergistically exert their flexibility, water resistance and corrosion resistance. Therefore, through the synergistic effect of the bisphenol A epoxy resin, the epoxy-based silane coupling agent, the polyacrylic substance and the modified silicone oil, the modified epoxy resin cured film can have better hardness, toughness, water resistance and corrosion resistance.

[0020] In some embodiments, the epoxy-based silane coupling agent is selected from γ-glycidoxypropyltrimethoxysilane or 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane coupling agent. The γ-glycidoxypropyltrimethoxysilane, due to the presence of ether bond, on the one hand facilitates the appropriate improvement of the toughness of the cross-linked part, and on the other hand facilitates the assistance of the ring-opening reaction of the epoxy group thereon. The 2-(3,4-epoxycyclohexyl)ethyl triethoxysilane coupling agent, due to the introduction of cyclohexane group and the shortening of the flexible chain part, facilitates the assistance of the improvement of the rigidity of the cross-linked part, thereby facilitating the improvement of the hardness of the modified waterborne epoxy resin cured film.

[0021] In some embodiments, the polyacrylic substance is selected from polymethacrylic acid. The selection of the above-mentioned polyacrylic substance, on the one hand, facilitates the appropriate improvement of the rigidity, and on the other hand, also facilitates the reduction of water absorption.

[0022] In some embodiments, the modification group of the amino-modified silicone oil is an amino end group, thereby facilitating the improvement of toughness and the improvement of reaction efficiency.

[0023] In some embodiments, the amino-modified silicone oil is selected from amino-terminated polydimethylsiloxane, thereby facilitating the further improvement of toughness and the improvement of reaction efficiency.

[0024] In some embodiments, the fraction of the amino silane coupling agent is 20-35 parts by weight, the fraction of the polyacrylic substance is 27-37 parts by weight, and the fraction of the amino-modified silicone oil is 110-150 parts by weight.

[0025] In some embodiments, the bisphenol A epoxy resin: the amino silane coupling agent: the polyacrylic substance is 20:5-6:6-7 by weight.

[0026] The selection of the above-mentioned ratio facilitates the further improvement of the hardness, toughness, water resistance and corrosion resistance of the modified epoxy resin cured film.

[0027] In some embodiments, the first catalyst is dibutyltin dilaurate, the second catalyst is an alkyl titanate catalyst such as tetrabutyl titanate, and the third catalyst is a tertiary amine catalyst such as triethylamine or N,N-dimethylbenzylamine.

[0028] In some embodiments, the modified waterborne epoxy resin is prepared by the following steps. Bisphenol A epoxy resin is dissolved in a solvent, stirred and heated to 110-130°C, then amino-modified silicone oil and a first catalyst are added for reaction at a temperature of 110-130°C for 4-6 hours.

[0029] After maintaining stirring and cooling to 30-50°C, an epoxy-based silane coupling agent and a second catalyst are added for reaction at a temperature of 35-50°C for 3-5 hours.

[0030] After maintaining stirring and heating to 80-120°C, a polyacrylic substance and a third catalyst are added for reaction at a temperature of 100-130°C for 3-4 hours. The preparation method provided herein has the advantages of relatively mild conditions and easy operation.

[0031] The following is specifically described by way of detailed examples.

[0032] Example 1 A modified waterborne epoxy resin, characterized in that the raw materials of the modified waterborne epoxy resin include, by weight: 100 parts of bisphenol A epoxy resin (E-51, brand Baling, manufacturer Baling Petrochemical), 15 parts of an epoxy-based silane coupling agent (γ-glycidoxypropyltrimethoxysilane, CAS No. 2530-83-8), 25 parts of a polyacrylic substance (polyacrylic acid, CAS No. 9007-20-9), 100 parts of amino-modified silicone oil (ammonia-terminated polydimethylsiloxane, brand Kermel), 65 parts of a solvent (toluene, brand Nantian), 1 part of a first catalyst (dibutyltin dilaurate, CAS No. 77-58-7, Shandong Yuanjin New Materials), 1 part of a second catalyst (tetrabutyl titanate, EC No. 227-006-8, Merck Life Sciences), and 1 part of a third catalyst (triethylamine, EC No. 204-469-4, Merck Life Sciences).

[0033] The siloxane group of the epoxy-based silane coupling agent is bonded to the secondary hydroxyl group of the bisphenol A epoxy resin, the carboxyl group of the polyacrylic substance is ring-opening reacted with the epoxy group of the grafted epoxy-based silane coupling agent, the amino group of the amino-modified silicone oil is ring-opening reacted with the epoxy group of the bisphenol A epoxy resin, the first catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the amino-modified silicone oil, the second catalyst is used to catalyze the reaction of the bisphenol A epoxy resin and the epoxy-based silane coupling agent, and the third catalyst is used to catalyze the grafted epoxy-based silane coupling agent and the polyacrylic substance.

[0034] Specifically, the modified waterborne epoxy resin is obtained by the following steps.

[0035] The bisphenol A epoxy resin is dissolved in a solvent, stirred and heated to 120°C, then the amino-modified silicone oil and the first catalyst are added for reaction, the reaction temperature is 125°C, and the reaction time is 5.2 hours.

[0036] After stirring and cooling to 45°C, the epoxy-based silane coupling agent and the second catalyst are added for reaction, the reaction temperature is 45°C, and the reaction time is 4.3 hours.

[0037] After stirring and heating to 110°C, the polyacrylic substance and the third catalyst are added for reaction, the reaction temperature is 120°C, and the reaction time is 3.5 hours.

[0038] Example 2 The difference from Example 1 is that the epoxy-based silane coupling agent is selected as 2-(3,4-epoxycyclohexyl) ethyl triethoxysilane coupling agent (CAS number: 10217-34-2, Hubei Jianchu Biomedicine Co., Ltd.), in step 2 of the preparation method, after stirring and cooling to 30°C, the epoxy-based silane coupling agent and the second catalyst are added for reaction, the reaction temperature is 35°C, and the reaction time is 5 hours, in step 3 of the preparation method, after stirring and heating to 80°C, the polyacrylic substance and the third catalyst are added for reaction, the reaction temperature is 100°C, and the reaction time is 4 hours.

[0039] Example 3 The difference from Example 1 is that the polyacrylic substance is selected as polymethacrylic acid (CAS number: 25087-26-7, Macklin), in step 3 of the preparation method, after stirring and heating to 120°C, the polyacrylic substance and the third catalyst are added for reaction, the reaction temperature is 130°C, and the reaction time is 3 hours, and the third catalyst is selected as N,N-dimethylbenzylamine.

[0040] Example 4 The difference from Example 1 is that the fraction of the amino silane coupling agent is 20 parts, the fraction of the polyacrylic substance is 26 parts, the fraction of the amino-modified silicone oil is 105 parts, the fraction of the solvent is 67 parts, the fraction of the first catalyst is 1.5 parts, the fraction of the second catalyst is 1.7 parts, and the fraction of the third catalyst is 2 parts by weight.

[0041] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 110°C, after which the amino-modified silicone oil and the first catalyst are added to react, the reaction temperature is 120°C, and the reaction time is 6 hours.

[0042] In Step 2, stirring is maintained and the temperature is lowered to 50°C, after which the epoxy-based silane coupling agent and the second catalyst are added to react, the reaction temperature is 50°C, and the reaction time is 3 hours.

[0043] In Step 3, stirring is maintained and the temperature is warmed to 80°C, after which the polyacrylic substance and the third catalyst are added to react, the reaction temperature is 100°C, and the reaction time is 4 hours.

[0044] Example 5 The difference from Example 1 is that the fraction of the amino silane coupling agent is 20 parts, the fraction of the polyacrylic substance is 27 parts, the fraction of the amino-modified silicone oil is 110 parts, the fraction of the solvent is 68 parts, the fraction of the first catalyst is 1.8 parts, the fraction of the second catalyst is 1.7 parts, and the fraction of the third catalyst is 2 parts by weight.

[0045] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 113°C, after which the amino-modified silicone oil and the first catalyst are added to react, the reaction temperature is 121°C, and the reaction time is 5.5 hours.

[0046] In Step 2, stirring is maintained and the temperature is lowered to 48°C, after which the epoxy-based silane coupling agent and the second catalyst are added to react, the reaction temperature is 50°C, and the reaction time is 3.2 hours.

[0047] In Step 3, stirring is maintained and the temperature is warmed to 85°C, after which the polyacrylic substance and the third catalyst are added to react, the reaction temperature is 105°C, and the reaction time is 3.7 hours.

[0048] Example 6 The difference from Example 1 is that the fraction of the amino silane coupling agent is 25 parts, the fraction of the polyacrylic substance is 30 parts, the fraction of the amino-modified silicone oil is 120 parts, the fraction of the solvent is 71 parts, the fraction of the first catalyst is 3.2 parts, the fraction of the second catalyst is 2.5 parts, and the fraction of the third catalyst is 3.5 parts by weight.

[0049] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 110°C, after which the amino-modified silicone oil and the first catalyst are added and reacted, with a reaction temperature of 110°C and a reaction time of 6 hours.

[0050] In Step 2, stirring is maintained and the temperature is lowered to 50°C, after which the epoxy-based silane coupling agent and the second catalyst are added and reacted, with a reaction temperature of 45°C and a reaction time of 4.1 hours.

[0051] In Step 3, stirring is maintained and the temperature is warmed to 95°C, after which the polyacrylic substance and the third catalyst are added and reacted, with a reaction temperature of 100°C and a reaction time of 4 hours.

[0052] Example 7 The difference from Example 1 is that the amino silane coupling agent is 30 parts, the polyacrylic substance is 35 parts, the amino-modified silicone oil is 140 parts, the solvent is 75 parts, the first catalyst is 4.1 parts, the second catalyst is 3.7 parts, and the third catalyst is 3.8 parts, by weight.

[0053] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 125°C, after which the amino-modified silicone oil and the first catalyst are added and reacted, with a reaction temperature of 120°C and a reaction time of 4.5 hours.

[0054] In Step 2, stirring is maintained and the temperature is lowered to 38°C, after which the epoxy-based silane coupling agent and the second catalyst are added and reacted, with a reaction temperature of 39°C and a reaction time of 4.8 hours.

[0055] In Step 3, stirring is maintained and the temperature is warmed to 101°C, after which the polyacrylic substance and the third catalyst are added and reacted, with a reaction temperature of 105°C and a reaction time of 3.7 hours.

[0056] Example 8 The difference from Example 7 is that the amino silane coupling agent is 35 parts, the polyacrylic substance is 37 parts, the amino-modified silicone oil is 150 parts, the solvent is 75 parts, the first catalyst is 4.3 parts, the second catalyst is 3.9 parts, and the third catalyst is 3.9 parts, by weight.

[0057] Example 9 The difference from Example 1 is that the fraction of the amino silane coupling agent is 45 parts, the fraction of the polyacrylic substance is 41 parts, the fraction of the amino-modified silicone oil is 170 parts, the fraction of the solvent is 80 parts, the fraction of the first catalyst is 6 parts, the fraction of the second catalyst is 5 parts, and the fraction of the third catalyst is 5 parts by weight.

[0058] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 122°C, after which the amino-modified silicone oil and the first catalyst are added to react, the reaction temperature is 127°C, and the reaction time is 5 hours.

[0059] In Step 2, stirring is maintained and the temperature is lowered to 40°C, after which the epoxy-based silane coupling agent and the second catalyst are added to react, the reaction temperature is 45°C, and the reaction time is 4.5 hours.

[0060] In Step 3, stirring is maintained and the temperature is warmed to 108°C, after which the polyacrylic substance and the third catalyst are added to react, the reaction temperature is 115°C, and the reaction time is 4 hours.

[0061] Comparative Example 1 The difference from Example 1 is that the fraction of the amino silane coupling agent is 14 parts, the fraction of the polyacrylic substance is 24 parts, the fraction of the amino-modified silicone oil is 90 parts, the fraction of the solvent is 65 parts, the fraction of the first catalyst is 1 part, the fraction of the second catalyst is 1 part, and the fraction of the third catalyst is 1 part by weight.

[0062] In Step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred, and warmed to 114°C, after which the amino-modified silicone oil and the first catalyst are added to react, the reaction temperature is 117°C, and the reaction time is 6 hours.

[0063] In Step 2, stirring is maintained and the temperature is lowered to 44°C, after which the epoxy-based silane coupling agent and the second catalyst are added to react, the reaction temperature is 48°C, and the reaction time is 4.5 hours.

[0064] In Step 3, stirring is maintained and the temperature is warmed to 113°C, after which the polyacrylic substance and the third catalyst are added to react, the reaction temperature is 115°C, and the reaction time is 4 hours.

[0065] Comparative Example 2 The difference from Example 1 is that the fraction of the amino silane coupling agent is 45 parts, the fraction of the polyacrylic substance is 46 parts, the fraction of the amino-modified silicone oil is 171 parts, the fraction of the solvent is 81 parts, the fraction of the first catalyst is 6 parts, the fraction of the second catalyst is 5 parts, and the fraction of the third catalyst is 5 parts by weight.

[0066] In step 1 of the preparation method, the bisphenol A epoxy resin is dissolved in the solvent, stirred and heated to 124℃, then the amino-modified silicone oil and the first catalyst are added for reaction, the reaction temperature is 126℃, and the reaction time is 5.3 hours.

[0067] In step 2, stirring is maintained and the temperature is lowered to 41℃, then the epoxy-based silane coupling agent and the second catalyst are added for reaction, the reaction temperature is 46℃, and the reaction time is 4.7 hours.

[0068] In step 3, stirring is maintained and the temperature is raised to 107℃, then the polyacrylic substance and the third catalyst are added for reaction, the reaction temperature is 116℃, and the reaction time is 3.7 hours.

[0069] Comparative Example 3 The difference from Example 1 is that the epoxy-based silane coupling agent, the polyacrylic substance, the second catalyst and the third catalyst are not added. Correspondingly, steps 2 and 3 are not included in the preparation method.

[0070] Comparative Example 4 The difference from Example 1 is that the amino-modified silicone oil and the first catalyst are not added, and correspondingly, step 1 is not included in the preparation method.

[0071] The test results of the above examples and comparative examples are shown in the following table.

[0072]

[0073] Among them, the water resistance, acid resistance and alkali resistance are measured by the percentage of the increased mass after corresponding water treatment, acid treatment and alkali treatment to the mass before treatment. In water treatment, saturated water treatment is performed, in acid treatment, 5% sulfuric acid is soaked for 7 days, and in alkali treatment, saturated sodium hydroxide is soaked for 7 days. The hardness is measured by a Shore hardness tester. The bonding strength is determined by GB / T16777-2008, the unit is MPa, the tensile strength is determined by a universal testing machine, the test condition temperature is room temperature, the tensile rate is 10mm / min, and the unit of the tensile strength is MPa. The flexibility is determined by GB / T1731-1993. The modified epoxy resin is cured by epoxy resin curing agent 593, the addition amount of the epoxy resin curing agent 593 is 15%-20% of the total mass of the modified epoxy resin and water (specifically, the modified epoxy resin and water are mixed by stirring to prepare an aqueous emulsion, the ratio of the total mass of the raw materials of water and modified epoxy resin is 1:1, then the curing agent is added and mixed uniformly while stirring, and after mixing, the coating is left to cure into a film), the curing time is selected to be 1 day to meet the actual curing and drying.

[0074] The above embodiments are only the preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and substitutions made by those skilled in the art based on the present application shall fall within the scope of protection of the present application.

Claims

1. A modified waterborne epoxy resin, characterized in that, By weight, the raw materials of the modified waterborne epoxy resin include: 100 parts of bisphenol A epoxy resin, 15-45 parts of epoxy-based silane coupling agent, 25-41 parts of polyacrylic acid material, 100-170 parts of amino-modified silicone oil, 65-80 parts of solvent, 1-6 parts of first catalyst, 1-5 parts of second catalyst and 1-5 parts of third catalyst. The siloxane group of the epoxy-based silane coupling agent is bonded to the secondary hydroxyl group of the bisphenol A epoxy resin, the carboxyl group of the polyacrylic acid substance undergoes a ring-opening reaction with the epoxy group of the grafted epoxy-based silane coupling agent, the polyacrylic acid substance is selected from at least one of polyacrylic acid and polyalkylacrylic acid, the amino group of the amino-modified silicone oil undergoes a ring-opening reaction with the epoxy group of the bisphenol A epoxy resin, the first catalyst is used to catalyze the reaction between the bisphenol A epoxy resin and the amino-modified silicone oil, the second catalyst is used to catalyze the reaction between the bisphenol A epoxy resin and the epoxy-based silane coupling agent, and the third catalyst is used to catalyze the reaction between the grafted epoxy-based silane coupling agent and the polyacrylic acid substance.

2. The modified waterborne epoxy resin as described in claim 1, characterized in that, The epoxy-based silane coupling agent is selected from γ-glycidyl etheroxypropyltrimethoxysilane or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane coupling agent.

3. The modified waterborne epoxy resin as described in claim 2, characterized in that, The polyacrylic acid material is selected from polymethacrylic acid.

4. The modified waterborne epoxy resin as described in claim 3, characterized in that, The modifying group of the amino-modified silicone oil is a terminal amino group.

5. The modified waterborne epoxy resin as described in claim 4, characterized in that, The amino-modified silicone oil is selected from amino-terminated polydimethylsiloxane.

6. The modified waterborne epoxy resin as described in claim 4, characterized in that, By weight, the aminosilane coupling agent comprises 20-35 parts, the polyacrylic acid substance comprises 27-37 parts, and the amino-modified silicone oil comprises 110-150 parts.

7. The modified waterborne epoxy resin as described in claim 6, characterized in that, The ratio of bisphenol A epoxy resin, aminosilane coupling agent, and polyacrylic acid material by weight is 20:5-6:6-7.

8. The modified waterborne epoxy resin as described in claim 7, characterized in that, The ratio of bisphenol A epoxy resin to amino-modified silicone oil by weight is 5:6-7.

9. The modified waterborne epoxy resin as described in claim 1, characterized in that, The first catalyst is dibutyltin dilaurate, the second catalyst is a titanate alkyl ester catalyst, and the third catalyst is a tertiary amine catalyst.

10. The modified waterborne epoxy resin according to any one of claims 1-9, characterized in that, The modified waterborne epoxy resin was prepared by the following steps: Bisphenol A epoxy resin is dissolved in a solvent, stirred and heated to 110-130℃, then amino-modified silicone oil and the first catalyst are added to carry out the reaction at 110-130℃ for 4-6 hours. After maintaining stirring and cooling to 30-50℃, add epoxy-based silane coupling agent and second catalyst to carry out the reaction. The reaction temperature is 35-50℃ and the reaction time is 3-5 hours. After stirring and heating to 80-120℃, add polyacrylic acid substances and a third catalyst to carry out the reaction. The reaction temperature is 100-130℃ and the reaction time is 3-4 hours.

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