Methyl epoxy resin cured product and preparation method and application thereof, and methyl epoxy resin cured film and preparation method and application thereof

Abstract

The invention provides a methyl epoxy resin cured product and a preparation method and application thereof, and a methyl epoxy resin cured film and a preparation method and application thereof, and relates to the technical field of epoxy resin. According to the method, the methyl epichlorohydrin and the bisphenol A are used as initial raw materials, due to the existence of beta-methyl in the methyl epichlorohydrin, side reactions are few, and the prepared methyl epoxy resin is high in purity and low in total chlorine content. The methyl epoxy resin prepared by the invention contains methyl, so that the chemical solvent resistance and hydrophobic property of a methyl epoxy resin cured product are enhanced. Epoxy groups in the methyl epoxy resin react with the curing agent to form a cross-linked network, the curing efficiency and the curing degree are improved by adding the curing accelerator, the impact resistance, the tensile property and the bending resistance of a cured product are improved, meanwhile, the existence of methyl in the methyl epoxy resin enables the cross-linking density of the cured product to be reduced, and the curing effect of the cured product is improved. The arrangement regularity of the three-dimensional network structure is reduced, the brittleness is reduced, the toughness is enhanced, and the comprehensive mechanical property is excellent.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resins, and in particular to a methyl epoxy resin cured product and a preparation method and application thereof, a methyl epoxy resin cured film and a preparation method and application thereof. Background Art

[0002] Epoxy resins are widely used in coatings, construction, composite materials, electronics and other fields due to their excellent mechanical properties, chemical resistance, bonding properties and electrical insulation properties. Bisphenol A diglycidyl ether, which is obtained by reacting bisphenol A (BPA) and epichlorohydrin (ECH), accounts for about 90% of epoxy resins in the world and is an important general-purpose epoxy resin. However, the chemical solvent resistance of epoxy resin cured products obtained by curing existing epoxy resins needs to be further improved. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a methyl epoxy resin cured product and a preparation method and application thereof, a methyl epoxy resin cured film and a preparation method and application thereof. The methyl epoxy resin cured product and the methyl epoxy resin cured film provided by the present invention have excellent chemical solvent resistance.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing a methyl epoxy resin cured product, comprising the following steps:

[0006] Mixing bisphenol A, methyl epichlorohydrin and an etherification catalyst to carry out an etherification reaction to obtain bisphenol A methyl epichlorohydrin; the molar ratio of bisphenol A to methyl epichlorohydrin is 1:4-15;

[0007] The bisphenol A methyl chloroether alcohol, strong alkali solution and organic solvent are mixed to carry out epoxidation reaction to obtain methyl epoxy resin;

[0008] The methyl epoxy resin, curing agent and curing accelerator are mixed and cured to obtain a methyl epoxy resin cured product.

[0009] Preferably, the etherification catalyst comprises one or more of boron trifluoride etherate complex, tin tetrachloride, zinc perchlorate and quaternary ammonium salt; the mass of the etherification catalyst is 0.5-6% of the mass of bisphenol A;

[0010] The temperature of the etherification reaction is 50-110° C., and the time is 0.5-4 hours.

[0011] Preferably, the strong alkali in the strong alkali solution comprises an alkali metal hydroxide; the mass concentration of the strong alkali solution is 10-50%; the molar ratio of bisphenol A to the strong alkali is 1:1.8-2.2;

[0012] The organic solvent includes one or more of toluene, cyclohexane, dichloroethane and chloroform;

[0013] The temperature of the epoxidation reaction is 45-80° C. and the time is 1-6.5 hours.

[0014] Preferably, the curing accelerator includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol; the mass ratio of the methyl epoxy resin to the curing accelerator is 1:0.01-0.08;

[0015] The curing agent includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine; the mass ratio of the methyl epoxy resin to the curing agent is 1:0.2-0.45.

[0016] Preferably, the curing temperature is 70-230° C., and the heat preservation time is 3.5-10 hours.

[0017] The present invention also provides a methyl epoxy resin cured product obtained by the preparation method described in the above technical solution, wherein the methyl epoxy resin in the methyl epoxy resin cured product has a structure shown in Formula I:

[0018]

[0019] Among them, n is 0 to 0.8.

[0020] The present invention also provides a method for preparing a methyl epoxy resin cured film, comprising the following steps:

[0021] Prepare methyl epoxy resin according to the preparation method described in the above technical scheme;

[0022] The methyl epoxy resin, curing agent, curing accelerator and organic solvent are mixed, coated on the surface of a substrate and then cured to obtain a methyl epoxy resin cured film on the surface of the substrate.

[0023] Preferably, the curing accelerator includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol; the mass ratio of the methyl epoxy resin to the curing accelerator is 1:0.01-0.08;

[0024] The curing agent includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine; the mass ratio of the methyl epoxy resin to the curing agent is 1:0.2-0.45;

[0025] The organic solvent includes one or more of acetone, chloroform and N,N-dimethylformamide;

[0026] The curing temperature is 70-230° C., and the heat preservation time is 3.5-10 hours.

[0027] The present invention also provides a methyl epoxy resin cured film prepared by the preparation method described in the above technical solution, wherein the methyl epoxy resin in the methyl epoxy resin cured film has a structure shown in Formula I:

[0028]

[0029] Among them, n is 0 to 0.8.

[0030] The present invention also provides the use of the methyl epoxy resin cured product or the methyl epoxy resin cured film described in the above technical solution in adhesives, coatings, building materials or electronic industries.

[0031] The present invention uses methyl epichlorohydrin and bisphenol A as initial raw materials, performs an etherification reaction in the presence of an etherification catalyst, and then performs an epoxidation reaction in the presence of a strong alkali solution to prepare a methyl epoxy resin. Due to the presence of a β-methyl group in methyl epichlorohydrin, fewer side reactions occur during the etherification reaction and the epoxidation reaction, and the purity of the prepared methyl epoxy resin is high; moreover, the toxicity and volatility of methyl epichlorohydrin are lower than those of epichlorohydrin, and the reaction process is safer and more environmentally friendly. The present invention can improve the reaction rate and the selectivity of the target product by adding an etherification catalyst, and the total chlorine content in the prepared methyl epoxy resin is low. The structure of the methyl epoxy resin prepared by the present invention contains a methyl group, which enhances the chemical solvent resistance and hydrophobicity of the methyl epoxy resin cured product and the methyl epoxy resin cured film (collectively referred to as a cured material). The epoxy groups in the methyl epoxy resin react with the curing agent to form a cross-linked network, and the curing efficiency and degree of curing are improved by adding a curing accelerator; at the same time, the presence of methyl in the methyl epoxy resin reduces the cross-linking density of the cured material, reduces the regularity of the three-dimensional network structure, and causes the brittleness of the cured material to decrease, and the impact resistance, tensile resistance and bending resistance are enhanced, and the comprehensive mechanical properties of the cured material are excellent. The methyl epoxy resin cured material and the methyl epoxy resin cured film prepared by the present invention have excellent chemical solvent resistance, comprehensive mechanical properties and hydrophobic properties, and have good application potential in the fields of adhesives, coatings, construction, composite materials, and the electronics industry.

[0032] Moreover, the preparation method of the methyl epoxy resin cured product and the methyl epoxy resin cured film provided by the present invention has simple process, simple operation, safety and environmental protection, and is suitable for industrial production. DETAILED DESCRIPTION

[0033] The present invention provides a method for preparing a methyl epoxy resin cured product, comprising the following steps:

[0034] Mixing bisphenol A, methyl epichlorohydrin and an etherification catalyst to carry out an etherification reaction to obtain bisphenol A methyl epichlorohydrin; the molar ratio of bisphenol A to methyl epichlorohydrin is 1:4-15;

[0035] The bisphenol A methyl chloroether alcohol, strong alkali solution and organic solvent are mixed to carry out epoxidation reaction to obtain methyl epoxy resin;

[0036] The methyl epoxy resin, curing agent and curing accelerator are mixed and cured to obtain a methyl epoxy resin cured product.

[0037] Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products in the art.

[0038] The invention mixes bisphenol A, methyl epichlorohydrin and an etherification catalyst, performs an etherification reaction, and obtains bisphenol A methyl epichlorohydrin.

[0039] In the present invention, the molar ratio of bisphenol A to methyl epichlorohydrin is 1:4-15, and in specific embodiments, it can be 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14 or 1:15. Due to the presence of β-methyl in methyl epichlorohydrin, the methyl epoxy resin is prepared by using it as a raw material, and the side reactions are few and the purity of the methyl epoxy resin is high; moreover, the toxicity and volatility of methyl epichlorohydrin are lower than those of epichlorohydrin, and the reaction process is safer and more environmentally friendly.

[0040] In the present invention, the etherification catalyst preferably includes one or more of boron trifluoride etherate complex, tin tetrachloride, zinc perchlorate and quaternary ammonium salt, more preferably a mixed catalyst of boron trifluoride etherate and quaternary ammonium salt, boron trifluoride etherate or quaternary ammonium salt; the quaternary ammonium salt preferably includes one or more of benzyltrimethylammonium chloride, benzyltriethylammonium chloride and tetrabutylammonium bromide; the mass ratio of boron trifluoride etherate and quaternary ammonium salt in the mixed catalyst is preferably 1:0.3-0.7, and in specific embodiments it can be 1:0.3, 1:0.4, 1:0.5, 1:0.6 or 1:0.7. In the present invention, the mass of the etherification catalyst is 0.5-6% of the mass of bisphenol A, and in specific embodiments it can be 0.5%, 1%, 2%, 3%, 4%, 5% or 6%. The present invention can improve the reaction rate and the selectivity of the target product and reduce the total chlorine content in the methyl epoxy resin by adding the etherification catalyst and controlling the amount of the etherification catalyst.

[0041] In the present invention, the mixing preferably includes: mixing bisphenol A and methyl epichlorohydrin until dissolved, adding an etherification catalyst after heating and mixing; the temperature of the system after heating is preferably 50-70°C, and can be 65°C in a specific embodiment.

[0042] In the present invention, the temperature of the etherification reaction is preferably 50-110°C, and in specific embodiments it can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or 110°C; the time of the etherification reaction is preferably 0.5-4h, and in specific embodiments it can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h or 4h.

[0043] After the etherification reaction, the present invention preferably further comprises: recovering the methyl epichlorohydrin in the reaction solution obtained by the etherification reaction to obtain bisphenol A methyl chloroether alcohol. In the present invention, the recovery preferably comprises distillation, and the distillation temperature is preferably 80 to 145°C, and in specific embodiments, it can be 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 145°C; the vacuum degree of the distillation is preferably -0.06 to -0.1MPa, and in specific embodiments, it can be -0.06MPa, -0.07MPa, -0.08MPa, -0.09MPa or -0.1MPa. The methyl epichlorohydrin recovered by the present invention can be reused.

[0044] After obtaining bisphenol A methyl chloroether alcohol, the present invention mixes the bisphenol A methyl chloroether alcohol, a strong alkali solution and an organic solvent, and performs an epoxidation reaction to obtain a methyl epoxy resin.

[0045] In the present invention, the strong alkali in the strong alkali solution preferably includes an alkali metal hydroxide, and in a specific embodiment it can be at least one of NaOH and KOH; the mass concentration of the strong alkali solution is preferably 10-50%, and in a specific embodiment it can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% or 50%.

[0046] In the present invention, the molar ratio of bisphenol A to the strong alkali in the strong alkali solution is preferably 1:1.8-2.2, and in specific embodiments may be 1:1.8, 1:1.9, 1:2, 1:2.1 or 1:2.2.

[0047] In the present invention, the organic solvent preferably includes one or more of toluene, cyclohexane, dichloroethane and chloroform. In the present invention, the ratio of the amount of bisphenol A to the volume of the organic solvent is preferably 1 mol: 150-350 g, and in specific embodiments it can be 1: 150 g, 1 mol: 180 g, 1 mol: 200 g, 1 mol: 220 g, 1 mol: 250 g, 1 mol: 280 g, 1 mol: 300 g, 1 mol: 320 g or 1 mol: 350 g. In the present invention, the role of the organic solvent is to dilute the viscosity of the chloroether alcohol.

[0048] In the present invention, the mixing preferably comprises: mixing bisphenol A methyl chloroether alcohol and an organic solvent and then adding a strong alkali solution; when adding the strong alkali solution, the temperature of the system is preferably 45-60°C, and in a specific embodiment can be 45°C, 50°C, 55°C or 60°C.

[0049] In the present invention, the temperature of the epoxidation reaction is preferably 45-80°C, and in specific embodiments it can be 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, or 80°C; the time of the epoxidation reaction is preferably 1-6.5h, and in specific embodiments it can be 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, or 6.5h.

[0050] After the epoxidation reaction is completed, the present invention preferably further comprises: cooling the reaction system obtained by the epoxidation reaction to room temperature, filtering, separating alkaline water, washing the obtained organic phase with water until neutral, and removing the solvent by reduced pressure distillation to obtain methyl epoxy resin (liquid). In the present invention, the temperature of the reduced pressure distillation is preferably 65 to 150°C, and in specific embodiments, it can be 65°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C; the vacuum degree of the reduced pressure distillation is preferably -0.05 to -0.10MPa, and in specific embodiments, it can be -0.05MPa, -0.06MPa, -0.07MPa, -0.08MPa, -0.09MPa or -0.1MPa.

[0051] The methyl epoxy resin prepared by the invention has high purity and low total chlorine content, simple preparation process, environmental protection and safety, and is convenient for industrial production.

[0052] After obtaining the methyl epoxy resin, the present invention mixes the methyl epoxy resin, a curing agent and a curing accelerator, and performs curing to obtain a methyl epoxy resin cured product.

[0053] In the present invention, the curing accelerator preferably includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol. In the present invention, the mass ratio of the methyl epoxy resin to the curing accelerator is preferably 1:0.01-0.08, and in specific embodiments, it can be 1:0.01, 1:0.02, 1:0.03, 1:0.0, 1:0.05, 1:0.06, 1:0.07 or 1:0.08. By adding a curing accelerator, the present invention can improve the curing efficiency and curing degree, and enhance the impact resistance, tensile strength, bending resistance and chemical resistance of the methyl epoxy resin cured product.

[0054] In the present invention, the curing agent preferably includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine, etc. In the present invention, the mass ratio of the methyl epoxy resin to the curing agent is preferably 1:0.2-0.45, and in specific embodiments, it can be 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4 or 1:0.45.

[0055] The present invention has no particular limitation on the mixing as long as the raw materials can be mixed uniformly.

[0056] After the mixing, the present invention preferably further comprises: removing bubbles from the mixed material, and then performing subsequent curing. In the present invention, the degassing preferably comprises vacuum degassing; the vacuum degree of the vacuum degassing is preferably -0.09 to -0.1 MPa; the time of the vacuum degassing is preferably 10 to 40 minutes, and in a specific embodiment, it can be 10 minutes, 20 minutes, 30 minutes or 40 minutes.

[0057] In the present invention, the curing temperature is preferably 70-230°C, and the holding time is preferably 3.5-10h. In the present invention, the curing is preferably programmed curing, and the programmed curing preferably includes sequentially performing a first curing, a second curing, a third curing and a fourth curing; the first curing temperature is preferably 70-120°C, and in a specific embodiment it can be 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, and the holding time of the first curing is preferably 0.5-1.5h, and in a specific embodiment it can be 0.5h, 1h or 1.5h; the second curing temperature is preferably 125-145°C, and in a specific embodiment it can be 120°C, 125°C, 130°C, 135°C, 140°C or 145°C, and the holding time of the second curing is preferably The temperature of the third curing is preferably 150-170°C, and in a specific embodiment, it can be 150°C, 155°C, 160°C, 165°C or 170°C. The holding time of the third curing is preferably 2-5h, and in a specific embodiment, it can be 2h or 3h. The temperature of the fourth curing is preferably 175-230°C, and in a specific embodiment, it can be 170°C, 175°C, 180°C, 185°C, 190°C or 195°C. The holding time of the fourth curing is preferably 0.5-1.5h, and in a specific embodiment, it can be 0.5h, 1h or 1.5h. In the present invention, the curing is preferably carried out in a mold. The present invention has no special limitation on the mold, and a mold well known to those skilled in the art can be used.

[0058] After the curing is completed, the present invention preferably further comprises: cooling the cured product obtained by the curing to room temperature and then demolding to obtain a methyl epoxy resin cured product.

[0059] The present invention also provides a methyl epoxy resin cured product obtained by the preparation method described in the above technical solution, wherein the methyl epoxy resin in the methyl epoxy resin cured product has a structure shown in Formula I:

[0060]

[0061] Wherein, n is 0 to 0.8, and in specific embodiments may be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0062] Compared with existing epoxy resins, the mechanical properties of the methyl epoxy resin cured product provided by the present invention, such as impact resistance and tensile strength, are significantly improved, the chemical solvent resistance is improved, and the water absorption is significantly reduced, and it has greater application potential in the fields of adhesives, coatings, construction, composite materials, and the electronics industry.

[0063] The present invention also provides a method for preparing a methyl epoxy resin cured film, comprising the following steps:

[0064] Prepare methyl epoxy resin according to the preparation method described in the above technical scheme;

[0065] The methyl epoxy resin, curing agent, curing accelerator and organic solvent are mixed, coated on the surface of a substrate and then cured to obtain a methyl epoxy resin cured film on the surface of the substrate.

[0066] In the present invention, the curing accelerator preferably includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol. In the present invention, the mass ratio of the methyl epoxy resin to the curing accelerator is preferably 1:0.01-0.08, and in specific embodiments, it can be 1:0.01, 1:0.02, 1:0.03, 1:0.0, 1:0.05, 1:0.06, 1:0.07 or 1:0.08. By adding a curing accelerator, the present invention can improve the curing efficiency and curing degree, and further enhance the impact resistance, tensile strength, bending resistance and chemical resistance of the methyl epoxy resin cured film.

[0067] In the present invention, the curing agent preferably includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine, etc. In the present invention, the mass ratio of the methyl epoxy resin to the curing agent is preferably 1:0.2-0.45, and in specific embodiments, it can be 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4 or 1:0.45.

[0068] In the present invention, the organic solvent preferably includes one or more of acetone, chloroform and N,N-dimethylformamide. In the present invention, the mass ratio of the methyl epoxy resin to the organic solvent is preferably 1:0.2-0.4, and in specific embodiments, it can be 1:0.2, 1:0.3 or 1:0.4.

[0069] The present invention has no particular limitation on the mixing as long as the raw materials can be mixed uniformly.

[0070] In the present invention, the coating preferably includes spraying.

[0071] In the present invention, the curing temperature is preferably 70-230°C, and the holding time is preferably 3.5-10h. In the present invention, the curing is preferably programmed curing, and the programmed curing preferably includes sequentially performing a first curing, a second curing, a third curing and a fourth curing; the first curing temperature is preferably 70-120°C, and in a specific embodiment it can be 70°C, 80°C, 90°C, 100°C, 110°C or 120°C, and the holding time of the first curing is preferably 0.5-1.5h, and in a specific embodiment it can be 0.5h, 1h or 1.5h; the second curing temperature is preferably 125-145°C, and in a specific embodiment it can be 120°C, 125°C, 130°C, 135°C, 140°C or 145°C, and the holding time of the second curing is preferably The temperature of the third curing is preferably 150-170°C, and in a specific embodiment, it can be 150°C, 155°C, 160°C, 165°C or 170°C. The holding time of the third curing is preferably 2-5h, and in a specific embodiment, it can be 2h or 3h. The temperature of the fourth curing is preferably 175-230°C, and in a specific embodiment, it can be 170°C, 175°C, 180°C, 185°C, 190°C or 195°C. The holding time of the fourth curing is preferably 0.5-1.5h, and in a specific embodiment, it can be 0.5h, 1h or 1.5h. In the present invention, the curing is preferably carried out in a mold. The present invention has no special limitation on the mold, and a mold well known to those skilled in the art can be used.

[0072] After the curing is completed, the present invention preferably further comprises: cooling the cured product obtained by the curing to room temperature and then demolding to obtain a methyl epoxy resin cured product.

[0073] The present invention also provides a methyl epoxy resin cured film prepared by the preparation method described in the above technical solution, wherein the methyl epoxy resin in the methyl epoxy resin cured product has a structure shown in Formula I:

[0074]

[0075] Wherein, n is 0 to 0.8, and in specific embodiments may be 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0076] Compared with existing epoxy resins, the mechanical properties of the methyl epoxy resin cured film provided by the present invention, such as impact resistance and tensile strength, are significantly improved, the chemical solvent resistance is improved, and the water absorption is significantly reduced, and it has greater application potential in the fields of adhesives, coatings, construction, composite materials, and the electronics industry.

[0077] The present invention also provides the use of the methyl epoxy resin cured film or the methyl epoxy resin cured product described in the above technical solution in adhesives, coatings, composite materials, building materials or electronic industries. In the present invention, the electronic industry preferably includes electronic components or microelectronic packaging materials.

[0078] The structure of the raw material methyl epoxy resin used in the present invention contains methyl groups, which enhances the chemical solvent resistance and hydrophobicity of the methyl epoxy resin cured product and the methyl epoxy resin cured film (collectively referred to as the cured material). The epoxy group in the methyl epoxy resin reacts with the curing agent to form a cross-linked network, and the curing efficiency and degree of curing are improved by adding a curing accelerator; at the same time, the presence of methyl groups in the methyl epoxy resin reduces the cross-linking density of the cured material, reduces the regularity of the arrangement of the three-dimensional network structure, causes the brittleness of the cured material to decrease, and enhances the impact resistance, tensile strength and bending resistance, and the comprehensive mechanical properties of the cured material are excellent. The methyl epoxy resin cured product and the methyl epoxy resin cured film prepared by the present invention have excellent chemical solvent resistance, comprehensive mechanical properties and hydrophobicity, and have good application potential in the fields of adhesives, coatings, construction, composite materials, and the electronics industry.

[0079] In order to further illustrate the present invention, a methyl epoxy resin cured product and its preparation method and application, a methyl epoxy resin cured film and its preparation method and application provided by the present invention are described in detail below in combination with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0080] Example 1

[0081] The preparation method of methyl epoxy resin is as follows: add bisphenol A and methyl epichlorohydrin, stir until dissolved and evenly dispersed, heat to 65°C, add boron trifluoride ether, mix evenly, heat to 90°C and keep warm for 3h, recover methyl epichlorohydrin by reduced pressure distillation at 130°C and vacuum degree of -0.098MPa to obtain bisphenol A methyl chloroether alcohol; add toluene, control the temperature at 50°C, dropwise add 20wt% strong alkali solution, heat to 60°C, keep warm for 4h, after the reaction is finished, stand and cool, filter, separate alkali water, wash the obtained organic phase with water until neutral, remove the solvent by reduced pressure distillation at 120°C and vacuum degree of -0.098MPa to obtain liquid methyl epoxy resin, the epoxy value is 0.50mol / 100g, and the total chlorine content is 800ppm. The molar ratio of bisphenol A, methyl epichlorohydrin and sodium hydroxide is 1:10:2, the mass of boron trifluoride ether is 2% of the mass of bisphenol A, and the usage ratio of bisphenol A and toluene is 1 mol:200 g.

[0082] The preparation of the methyl epoxy resin cured product is as follows: methyl epoxy resin, diaminodiphenyl sulfone and 2-methylimidazole are mixed uniformly at a mass ratio of 100:27:5, bubbles are removed by vacuuming, and the mixture is transferred into a mold. The mixture is cured at 110°C for 1 hour, at 130°C for 1 hour, at 165°C for 3 hours, and at 185°C for 1 hour (the program curing conditions are recorded as: 110°C×1h+130°C×1h+165°C×3h+185°C×1h), cooled to room temperature, and demolded to obtain the methyl epoxy resin cured product.

[0083] Example 2

[0084] The preparation method of methyl epoxy resin is as follows: add bisphenol A and methyl epichlorohydrin, stir until dissolved and evenly dispersed, add benzyltrimethylammonium chloride when the temperature is raised to 65°C, mix evenly, raise the temperature to 90°C and keep warm for 3 hours, and recover methyl epichlorohydrin by reduced pressure distillation at 130°C and a vacuum degree of -0.098MPa to obtain bisphenol A methyl chloroether alcohol; add toluene, control the temperature at 50°C, dropwise add 20wt% strong alkali solution, raise the temperature to 60°C, keep warm for 4 hours, and after the reaction is completed, stand and cool, filter, separate the alkaline water, wash the obtained organic phase with water until neutral, and remove the solvent by reduced pressure distillation at 120°C and a vacuum degree of -0.098MPa to obtain a liquid methyl epoxy resin with an epoxy value of 0.46mol / 100g and a total chlorine content of 950ppm. The molar ratio of bisphenol A, methyl epichlorohydrin and sodium hydroxide is 1:10:2, the mass of benzyltrimethylammonium chloride is 2.5% of the mass of bisphenol A, and the usage ratio of bisphenol A and toluene is 1 mol:200 g.

[0085] The preparation of the methyl epoxy resin cured product is as follows: methyl epoxy resin, diaminodiphenyl sulfone and 2-methylimidazole are uniformly mixed in a mass ratio of 100:27:5, bubbles are removed by vacuuming, the mixture is transferred into a mold, and the mixture is cured under the conditions of 110°C×1h+130°C×1h+165°C×3h+185°C×1h, cooled to room temperature, and demolded to obtain the methyl epoxy resin cured product.

[0086] Example 3

[0087] The preparation method of methyl epoxy resin is as follows: add bisphenol A and methyl epichlorohydrin, stir until dissolved and evenly dispersed, add boron trifluoride etherate and benzyltrimethylammonium chloride when the temperature is raised to 65°C, mix evenly, raise the temperature to 90°C and keep warm for 3 hours, and recover methyl epichlorohydrin by reduced pressure distillation at 130°C and a vacuum degree of -0.098MPa to obtain bisphenol A methyl chloroether alcohol; add toluene, control the temperature at 50°C, dropwise add 20wt% strong alkali solution, raise the temperature to 60°C, keep warm for reaction for 4 hours, and after the reaction is completed, stand and cool, filter, separate the alkali water, wash the obtained organic phase with water until neutral, and remove the solvent by reduced pressure distillation at 120°C and a vacuum degree of -0.098MPa to obtain a liquid methyl epoxy resin with an epoxy value of 0.52mol / 100g and a total chlorine content of 650ppm. Among them, the molar ratio of bisphenol A, methyl epichlorohydrin and sodium hydroxide is 1:10:2, the mass of boron trifluoride ether is 2% of the mass of bisphenol A, the mass of benzyltrimethylammonium chloride is 1% of the mass of bisphenol A, and the usage ratio of bisphenol A and toluene is 1 mol:200g.

[0088] The preparation of the methyl epoxy resin cured product is as follows: methyl epoxy resin, diaminodiphenyl sulfone and 2-methylimidazole are uniformly mixed in a mass ratio of 100:27:5, bubbles are removed by vacuuming, and the mixture is transferred into a mold. The mixture is cured under the conditions of 110°C × 1h + 130°C × 1h + 165°C × 3h + 185°C × 1h, cooled to room temperature, and demolded to obtain the methyl epoxy resin cured product.

[0089] Comparative Example 1

[0090] The methyl epoxy resin and diaminodiphenyl sulfone prepared in Example 3 were uniformly mixed in a mass ratio of 100:27, bubbles were removed by vacuuming, and the mixture was transferred into a mold. The mixture was cured under the conditions of 140°C × 1h + 160°C × 2h + 185°C × 4h + 200°C × 1h, cooled to room temperature, and demolded to obtain a methyl epoxy resin cured product.

[0091] Comparative Example 2

[0092] Bisphenol A epoxy resin (E51), diaminodiphenyl sulfone and 2-methylimidazole were mixed uniformly in a mass ratio of 100:31:5, and the bubbles were removed by vacuuming, and the mixture was transferred into a mold. The mixture was cured under the conditions of 110℃×1h+130℃×1h+165℃×3h+185℃×1h, cooled to room temperature, and demolded to obtain a methyl epoxy resin cured product. The mixture was cooled to room temperature, and demolded to obtain a bisphenol A epoxy resin cured product. The molar ratio of epoxy resin to diaminodiphenyl sulfone in Comparative Example 2 and Examples 1 to 3 was the same, which was 2:1.

[0093] Test Example 1

[0094] The performance test results of each epoxy resin cured product prepared in Examples 1 to 3 and Comparative Examples 1 to 2 are shown in Table 1. Among them, the impact strength test method is GB / T 1843-2008 Determination of the cantilever beam impact strength of plastics. The bending performance (bending strength and bending modulus) test method is GB / T 9341-2008 Determination of the bending performance of plastics. The tensile performance (tensile strength, tensile modulus and elongation at break) test method is GB / T1040.2-2022 Determination of the tensile properties of plastics. The water absorption test method is GB / T 1034-2008 Determination of the water absorption of plastics.

[0095] Table 1 Mechanical properties test results of epoxy resin cured products

[0096]

[0097] As shown in Table 1, the methyl epoxy resin provided by the present invention can significantly improve the mechanical properties and impact strength of the methyl epoxy resin cured product, wherein the impact strength of the methyl epoxy resin cured product can reach 38.41 kJ / m 2 , tensile strength can reach 77.36MPa, flexural strength can reach 121.10MPa, flexural modulus can reach 3.31GPa, tensile modulus can reach 1.43GPa, elongation at break can reach 4.55%, water absorption rate is as low as 1.77%, with good comprehensive mechanical properties and hydrophobic properties. At the same time, the introduction of curing accelerator improves the curing efficiency and curing degree of methyl epoxy resin cured product, thus having better comprehensive performance.

[0098] Example 4

[0099] The methyl epoxy resin, diaminodiphenyl sulfone and 2-methylimidazole prepared in Example 3 were added to a beaker in a mass ratio of 100:27:5, and acetone was added and stirred until uniformly mixed to obtain a mixture. The mixture was evenly sprayed onto a tinplate sheet and cured under the conditions of 110°C × 1h + 130°C × 1h + 165°C × 3h + 185°C × 1h to obtain a methyl epoxy resin cured film. The mass ratio of methyl epoxy resin to acetone was 1:0.3.

[0100] Comparative Example 3

[0101] Add bisphenol A epoxy resin (E51), diaminodiphenyl sulfone and 2-methylimidazole into a beaker in a mass ratio of 100:31:5, add acetone, stir until mixed evenly, and keep the viscosity low. Spray the mixture evenly onto a tinplate sheet, and program cure at 110°C × 1h + 130°C × 2h + 165°C × 3h + 185°C × 1h to obtain a bisphenol A epoxy resin cured film. Among them, the mass ratio of methyl epoxy resin to acetone is 1:0.3. The molar ratio of epoxy resin to diaminodiphenyl sulfone in Comparative Example 3 and Example 4 is the same, both 2:1.

[0102] Test Example 2

[0103] The performance test results of the epoxy resin cured films prepared in Example 4 and Comparative Example 3 are shown in Table 2. The hardness test method is to use the hand-drawing method to test the hardness of the epoxy cured film, using Chinese pencils, and the pencil hardness levels from low to high are 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, and 9H. The solvent rubbing resistance test method is GB / T 23989-2009 coating solvent rubbing resistance determination method.

[0104] Table 2 Test results of chemical solvent resistance of epoxy resin cured film

[0105] Cured film hardness Acetone wiping times THF wiping resistance Toluene wiping resistance Example 4 5～6H 141 times 122 times 100 times Comparative Example 3 3H 82 times 89 times 76 times

[0106] It can be seen from Table 2 that the methyl epoxy resin cured film provided by the present invention has good chemical solvent resistance.

[0107] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a methyl epoxy resin cured product, characterized in that: The following steps are involved: Mixing bisphenol A, methyl epichlorohydrin and an etherification catalyst to carry out an etherification reaction to obtain bisphenol A methyl epichlorohydrin; the molar ratio of bisphenol A to methyl epichlorohydrin is 1:4-15; The bisphenol A methyl chloroether alcohol, strong alkali solution and organic solvent are mixed to carry out epoxidation reaction to obtain methyl epoxy resin; The methyl epoxy resin, curing agent and curing accelerator are mixed and cured to obtain a methyl epoxy resin cured product.

2. The preparation method according to claim 1, characterized in that: The etherification catalyst comprises one or more of boron trifluoride ether complex, tin tetrachloride, zinc perchlorate and quaternary ammonium salt; the mass of the etherification catalyst is 0.5-6% of the mass of bisphenol A; The temperature of the etherification reaction is 50-110° C., and the time is 0.5-4 hours.

3. The preparation method according to claim 1, characterized in that: The strong alkali in the strong alkali solution includes alkali metal hydroxide; the mass concentration of the strong alkali solution is 10-50%; the molar ratio of bisphenol A to the strong alkali is 1:1.8-2.2; The organic solvent includes one or more of toluene, cyclohexane, dichloroethane and chloroform; The temperature of the epoxidation reaction is 45-80° C. and the time is 1-6.5 hours.

4. The preparation method according to claim 1, characterized in that: The curing accelerator includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol; the mass ratio of the methyl epoxy resin to the curing accelerator is 1:0.01-0.08; The curing agent includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine; the mass ratio of the methyl epoxy resin to the curing agent is 1:0.2-0.

45.

5. The preparation method according to claim 1 or 4, characterized in that: The curing temperature is 70-230° C., and the heat preservation time is 3.5-10 hours.

6. The methyl epoxy resin cured product obtained by the preparation method according to any one of claims 1 to 5, wherein the methyl epoxy resin in the methyl epoxy resin cured product has a structure shown in Formula I: in, n is 0 to 0.

8.

7. A method for preparing a methyl epoxy resin cured film, characterized in that: The following steps are involved: Prepare methyl epoxy resin according to the preparation method according to any one of claims 1 to 3; The methyl epoxy resin, curing agent, curing accelerator and organic solvent are mixed, coated on the surface of a substrate and then cured to obtain a methyl epoxy resin cured film on the surface of the substrate.

8. The preparation method according to claim 7, characterized in that: The curing accelerator includes one or more of 2-methylimidazole, 2-ethylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol; the mass ratio of the methyl epoxy resin to the curing accelerator is 1:0.01-0.08; The curing agent includes one or more of diaminodiphenylmethane, diaminodiphenyl sulfone, diethylenetriamine, isophoronediamine and polyetheramine; the mass ratio of the methyl epoxy resin to the curing agent is 1:0.2-0.45; The organic solvent includes one or more of acetone, chloroform, and N,N-dimethylformamide; The curing temperature is 70-230° C., and the heat preservation time is 3.5-10 hours.

9. The methyl epoxy resin cured film prepared by the preparation method according to claim 7 or 8, wherein the methyl epoxy resin in the methyl epoxy resin cured film has a structure shown in Formula I: in, n is 0 to 0.

8.

10. Use of the methyl epoxy resin cured product according to claim 6 or the methyl epoxy resin cured film according to claim 9 in adhesives, coatings, building materials or electronics industries.

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