Epoxy resin, epoxy resin composition, curable composition, epoxy resin product and preparation method thereof

Abstract

The invention relates to the field of epoxy resin synthesis, and discloses an epoxy resin, an epoxy resin composition, a curable composition, an epoxy resin product and a preparation method thereof.The preparation method comprises the step that in the presence of a cosolvent, a bisphenol compound shown in the formula (1) and epoxy chloropropane make contact with a basic catalyst; the alkaline catalyst is an alkaline solution with the concentration of 35-70 wt%; the cosolvent is selected from at least two of a C6-C12 non-substituted aromatic compound, a C1-C4 alkyl monosubstituted or polysubstituted aromatic compound, a C2-C11 alcohol, a C4-C10 straight chain or branched chain ketone, a C4-C7 naphthenone and a C4-C10 ester. According to the preparation method, a high-concentration alkaline catalyst is used, and the wastewater discharge amount, COD and TOC are reduced. The epoxy resin product prepared from the epoxy resin prepared by the preparation method has excellent mechanical property, water absorption property, solvent resistance and insulating property. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of epoxy resin synthesis, and in particular to a method for preparing epoxy resin, the epoxy resin prepared by the method, an epoxy resin composition containing the epoxy resin, a curable composition, and an epoxy resin product obtained by curing the curable composition. Background Art

[0002] Epoxy resins are widely used, especially as insulating materials in electrical equipment, such as electrified railways, semiconductor substrates, transformers, substations, etc. With the development of new technologies, the electrical industry has put forward higher requirements for insulation performance and corrosion resistance, and requires epoxy resin insulation sheets to have low water absorption, high heat resistance, and excellent mechanical properties.

[0003] So far, diphenol propane epoxy resin is the epoxy resin with the largest output and the widest application. In the traditional process of producing diphenol propane epoxy resin, 10wt% NaOH solution is mainly used to react with diphenol propane in aqueous solution to generate BPA-Na + , and then BPA-Na + The method is characterized in that the obtained epoxy resin product has poor corrosion resistance and insulation, and has large wastewater discharge, COD (chemical oxygen demand) and TOC (total organic carbon), which are difficult to handle.

[0004] For example, the traditional one-step method for synthesizing solid epoxy resins discharges 2 tons / ton of high-NaCl wastewater per unit product, with COD reaching 20,000 mg / L and TOC of 5,500 mg / L, which increases the difficulty of wastewater treatment. The epoxy resin product has poor corrosion resistance and insulation properties. After immersion in water, the insulation resistance is 10,000 MΩ, the water absorption is >45 mg, and the solvent resistance △W is >0.08.

[0005] In summary, there is an urgent need for a method for preparing an epoxy resin with low wastewater discharge, COD and TOC and excellent product mechanical properties, anti-corrosion properties and insulation properties. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems of high wastewater discharge, high COD and TOC and poor product insulation and corrosion resistance in the epoxy resin preparation process in the prior art, and to provide an epoxy resin preparation method, epoxy resin, epoxy resin composition, curable composition and epoxy resin product. The preparation method can effectively reduce wastewater discharge, COD and TOC, and the product has excellent mechanical properties, corrosion resistance and insulation properties.

[0007] In order to achieve the above object, the first aspect of the present invention provides a method for preparing an epoxy resin, wherein the preparation method comprises contacting a bisphenol compound represented by formula (1) and epichlorohydrin with a basic catalyst in the presence of a co-solvent;

[0008]

[0009] In formula (1), R1 and R3 are each independently hydrogen, C1-C4 alkyl or substituted alkyl, Br or Cl; R2 is C1-C9 alkylene;

[0010] The alkaline catalyst is an alkaline solution with a concentration of 35-70wt%; the co-solvent is selected from at least two of C6-C12 non-substituted aromatic compounds, C1-C4 alkyl mono-substituted or poly-substituted aromatic compounds, C2-C11 alcohols, C4-C10 straight-chain or branched ketones, C4-C7 cycloalkanones and C4-C10 esters.

[0011] The second aspect of the present invention provides an epoxy resin prepared by the above preparation method.

[0012] The third aspect of the present invention provides an epoxy resin composition, wherein the epoxy resin composition comprises the above-mentioned epoxy resin and a novolac epoxy resin;

[0013] Wherein, based on the total weight of the epoxy resin composition, the content of the epoxy resin is 40-60wt%, and the content of the phenolic epoxy resin is 40-60wt%.

[0014] A fourth aspect of the present invention provides a curable resin composition, wherein the curable resin composition comprises a first component and a second component, wherein the first component and the second component exist independently;

[0015] The first component includes the above-mentioned epoxy resin composition;

[0016] The second component includes a curing agent.

[0017] A fifth aspect of the present invention provides an epoxy resin product, wherein the epoxy resin product is obtained by mixing and curing the above-mentioned curable resin composition.

[0018] Through the above technical solution, the beneficial effects achieved by the present invention are as follows:

[0019] (1) The preparation method of the epoxy resin provided by the present invention adopts a specific solvent as a co-solvent, so that a high concentration of alkaline catalyst can be used in the preparation process of the diphenol propane epoxy resin, thereby improving the utilization rate of the alkaline catalyst, thereby effectively reducing the amount of wastewater discharged, COD and TOC; and the method can reduce the purity requirements for diphenol propane, without the need to specifically remove 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)propane and 2,2-bis-(4'-hydroxybenzene)propane therein.

[0020] (2) The epoxy resin product provided by the present invention has excellent mechanical properties, corrosion resistance and insulation properties. DETAILED DESCRIPTION

[0021] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0022] The first aspect of the present invention provides a method for preparing an epoxy resin, wherein the preparation method comprises contacting a bisphenol compound represented by formula (1) and epichlorohydrin with a basic catalyst in the presence of a cosolvent;

[0023]

[0024] In formula (1), R1 and R3 are each independently hydrogen, C1-C4 alkyl or substituted alkyl, Br or Cl; R2 is C1-C9 alkylene;

[0025] The alkaline catalyst is an alkaline solution with a concentration of 35-70wt%; the co-solvent is selected from at least two of C6-C12 non-substituted aromatic compounds, C1-C4 alkyl mono-substituted or poly-substituted aromatic compounds, C2-C11 alcohols, C4-C10 straight-chain or branched ketones, C4-C7 cycloalkanones and C4-C10 esters.

[0026] The present invention uses a cosolvent to enable the use of a high-concentration alkaline catalyst in the epoxy resin preparation process, thereby improving the utilization rate of the alkaline catalyst and effectively reducing the wastewater discharge, COD and TOC; and the method can reduce the purity requirement for diphenol propane, without the need to specifically remove 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)propane and 2,2-bis-(4'-hydroxybenzene)propane therein.

[0027] Preferably, the concentration of the alkaline solution is 40-65 wt %.

[0028] Preferably, the mass ratio of the alkaline catalyst to the epichlorohydrin is 0.5-1.5:1; the mass ratio of the co-solvent to the epichlorohydrin is 2-7:1.

[0029] Preferably, the mass ratio of the bisphenol compound to the epichlorohydrin is 1.3-2:1.

[0030] According to the present invention, the alkaline catalyst is selected from at least one of NaOH solution, KOH solution, Ba(OH)2 solution, Ca(OH)2 solution, NaHCO3 solution, Na2CO3 solution and triethanolamine.

[0031] Preferably, the alkaline catalyst is NaOH solution.

[0032] Preferably, in the presence of a co-solvent, the bisphenol compound represented by formula (1) and epichlorohydrin are contacted with an alkaline catalyst by adding the alkaline catalyst and / or the co-solvent to the bisphenol compound represented by formula (1) and epichlorohydrin in batches.

[0033] According to the present invention, the time interval between adding two adjacent batches is 10-180 minutes.

[0034] In the present invention, the inventors found that by adding alkaline catalysts in batches, epoxy resins with different weight average molecular weights can be obtained, further reducing wastewater discharge, COD and TOC.

[0035] In the present invention, the types of the alkaline catalysts added in batches may be the same or different.

[0036] More preferably, the concentration and / or amount of the alkaline catalyst in the latter batch is not less than the concentration and amount of the alkaline catalyst in the former batch.

[0037] Further preferably, the amount of the alkaline catalyst in the latter batch is 0-450 wt % greater than that in the former batch.

[0038] In the present invention, the inventors found that when the amount of the alkaline catalyst is increased, the reaction is carried out in an orderly gradient, the number average molecular weight of the epoxy resin can be controlled, and the epoxy resin products prepared therefrom meet the requirements of different number average molecular weights.

[0039] According to the present invention, preferably, the alkaline catalyst is added to the bisphenol compound represented by formula (1) and epichlorohydrin in 2-4 batches.

[0040] Preferably, the alkaline catalyst is added to the bisphenol compound represented by formula (1) and epichlorohydrin in four batches, and the third batch of alkaline catalyst is 0-200wt% of the amount of the second batch of alkaline catalyst, and the fourth batch of alkaline catalyst is 300-450wt% of the amount of the third batch of alkaline catalyst.

[0041] In the present invention, adding the co-solvent in batches can effectively control the viscosity of the reaction system, thereby reducing side reactions.

[0042] In the present invention, the types of the co-solvents added in batches may be the same or different.

[0043] According to the present invention, preferably, the co-solvent is added to the bisphenol compound represented by formula (1) and epichlorohydrin in 2-4 batches.

[0044] Preferably, the amount of the co-solvent used in the latter batch is not less than the amount of the co-solvent used in the former batch.

[0045] In a specific embodiment of the present invention, preferably, the co-solvent is added to the bisphenol compound represented by formula (1) and epichlorohydrin in two batches.

[0046] Furthermore, the co-solvent is selected from at least two of the solvents having polarities of 2-5 and 10-28.

[0047] In the present invention, co-solvents with different polarities are used in combination, so that 35-70wt% of a high-concentration alkaline catalyst can be used in the preparation process of the diphenol propane epoxy resin, thereby improving the utilization rate of the alkaline catalyst.

[0048] In the present invention, the polarity is obtained by looking up in a solvent handbook.

[0049] Furthermore, among the co-solvents, the polarity difference between different solvents is 7-21.

[0050] Preferably, the co-solvent is selected from at least two of the co-solvents selected from benzene, butanol, pentanol, hexanol, 2-pentanone and butanone.

[0051] More preferably, the co-solvent is selected from at least one of pentanol and benzene in a mass ratio of 1:7-10, hexanol and benzene in a mass ratio of 1:2-3, 2-pentanone and butanone in a mass ratio of 1:0.5-2, benzene and butanone in a mass ratio of 1:0.5-2, benzene and 2-pentanone in a mass ratio of 1:0.5-1.5, n-butanol and benzene in a mass ratio of 1:1.2-3, butanol and benzene in a mass ratio of 1:0.5-2, and pentanol and 2-pentanone in a mass ratio of 1:0.5-1.

[0052] According to the present invention, R1 and R3 may be hydrogen.

[0053] According to the present invention, R2 may be a C1-C6 alkylene group.

[0054] Preferably, the bisphenol compound is 2-(4'-hydroxyphenyl)-2-(2'-hydroxyphenyl)propane ( R1 and R3 are hydrogen, R2 is propylene), 2,2-bis-(4'-hydroxyphenyl)propane ( R1, R3 are hydrogen, R2 is propylene) and diphenol propane ( R1 and R3 are hydrogen, and R2 is propylene).

[0055] In the present invention, the use of a co-solvent enables the use of a high concentration of catalyst and reduces the requirements for raw materials. When the raw materials contain an appropriate amount of isomers of bisphenol A, a relatively high yield can still be maintained, thereby reducing the production cost.

[0056] Further preferably, based on the total weight of the bisphenol compound, the content of the diphenol propane is 96-98wt%, the content of the 2-(4'-hydroxyphenyl)-2-(2'-hydroxyphenyl) propane is 1-3wt%, and the content of 2,2-bis-(4'-hydroxyphenyl) propane is 0-1wt%. This content range makes it unnecessary to specially purify the raw materials.

[0057] According to the present invention, the contact conditions include: the time can be 10-120 minutes; the temperature can be 40-50° C. When the alkaline catalyst and / or co-solvent are added in batches, the temperature of each addition can be the same or different.

[0058] The second aspect of the present invention provides an epoxy resin prepared by the above preparation method.

[0059] Preferably, the number average molecular weight of the epoxy resin is 300 g / mol-2200 g / mol. The number average molecular weight of the epoxy resin is measured by gel chromatography.

[0060] Preferably, the softening point of the epoxy resin is 21-110° C. The softening point of the epoxy resin is tested according to the provisions of GB / T27809-2011.

[0061] Preferably, the melt viscosity of the epoxy resin at 150° C. is 200-4500 mPa·s. The melt viscosity of the epoxy resin is measured at 150° C. using a Brookfield cone and plate viscometer with a 2# rotor.

[0062] The third aspect of the present invention provides an epoxy resin composition, wherein the epoxy resin composition comprises the above-mentioned epoxy resin and a novolac epoxy resin;

[0063] Wherein, based on the total weight of the epoxy resin composition, the content of the epoxy resin is 40-60wt%, and the content of the phenolic epoxy resin is 40-60wt%.

[0064] Preferably, based on the total weight of the epoxy resin composition, the content of the epoxy resin is 50-60wt%, and the content of the novolac epoxy resin is 40-50wt%.

[0065] Preferably, the structure of the phenolic epoxy resin is as shown in formula (2),

[0066]

[0067] In formula (2), R4 and R9 are each independently hydrogen, C1-C4 alkyl or substituted alkyl; R5, R6, R7, and R8 are each independently hydrogen, C1-C4 alkyl or substituted alkyl.

[0068] A fourth aspect of the present invention provides a curable resin composition, wherein the curable resin composition comprises a first component and a second component, wherein the first component and the second component exist independently;

[0069] The first component includes the above-mentioned epoxy resin composition;

[0070] The second component includes a curing agent.

[0071] In the present invention, there is no particular limitation on the equipment for mixing the epoxy resin composition. Conventional equipment in the art can be used to mix the first component and the second component in the epoxy resin composition, such as a twin-screw extruder or a stirrer, as long as the first component and the second component can be fully mixed.

[0072] According to the present invention, the amount of the second component is 3-10 parts by weight relative to 100 parts by weight of the first component.

[0073] According to the present invention, the curing agent is selected from at least one of dicyandiamide, dimethylimidazole, dimethylbenzylamine, linear phenolic resin and adipic acid dihydrazide.

[0074] Furthermore, the curing agent is dicyandiamide, dimethylimidazole and dimethylbenzylamine.

[0075] Furthermore, the mass ratio of dicyandiamide, dimethylimidazole and dimethylbenzylamine is 20-40:0.2-0.8:1.

[0076] A fifth aspect of the present invention provides an epoxy resin product, wherein the epoxy resin product is obtained by mixing and curing the above-mentioned curable resin composition.

[0077] In the present invention, the epoxy resin product has excellent mechanical properties, anti-corrosion properties and insulation properties.

[0078] In the present invention, the anti-corrosion performance is reflected in water absorption and solvent resistance, and the solvent is ethyl acetate.

[0079] In some embodiments of the present invention, the curing temperature is 150-200° C. and the curing time is 20-60 min.

[0080] Preferably, the insulation resistance of the epoxy resin product after immersion in water is 50000-500000 MΩ. The insulation resistance of the epoxy resin product after immersion in water is tested according to the provisions of GB / T1363.2-2009.

[0081] Preferably, the mass change rate of the epoxy resin product after being immersed in ethyl acetate at 90° C. for 0.5 h is not greater than 0.03%. The mass change rate of the epoxy resin product is measured according to GB / T1303.2-2009.

[0082] The epoxy resin product provided by the present invention can be applied to machinery, electronics and electrical applications.

[0083] The present invention will be described in detail below through examples.

[0084] The number average molecular weight of the epoxy resin was measured by gel chromatography.

[0085] Epoxy resin yield = (actual epoxy resin yield / theoretical epoxy resin yield)*100%.

[0086] The COD value of wastewater is tested in accordance with the provisions of HJ 828-2017.

[0087] The TOC value of wastewater is measured by total organic carbon analyzer using the subtraction method.

[0088] The flexural strength of epoxy resin products is tested in accordance with the provisions of GB / T1303.4-2009.

[0089] The water absorption of epoxy resin products is tested in accordance with the provisions of GB / T1303.2-2009.

[0090] The solvent resistance of epoxy resin products was tested in accordance with the provisions of GB / T11547-2008, and the test solution was ethyl acetate.

[0091] The insulation resistance of epoxy resin products after immersion in water shall be tested in accordance with the provisions of GB / T1303.2-2009.

[0092] The raw materials used in the embodiments, test examples and comparative examples are all commercially available.

[0093] Example I - Epoxy Resin

[0094] Example I-1

[0095] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were added to a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was stirred for 2 hours. Add 86 g of butanone and 86 g of 2-pentanone, heat to 45°C, add 5 g of 60 wt% caustic soda after the diphenol propane is fully dissolved, maintain for 60 minutes, add 86 g of butanone, 86 g of 2-pentanone and 6 g of 60 wt% caustic soda, maintain for 60 minutes; add 10 g of 60 wt% caustic soda, maintain for 10 minutes, add 35 g of 60 wt% caustic soda, maintain for 120 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin A1.

[0096] Example I-2

[0097] 60g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were added to a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was stirred for 2 hours. Add 122g of benzene and 52g of n-hexanol, heat to 50°C, and after the diphenol propane is fully dissolved, add 5g of 45wt% caustic soda, maintain for 60 minutes, add 122g of benzene, 52g of n-hexanol and 10g of 45wt% caustic soda, maintain for 120 minutes; add 10g of 45wt% caustic soda, maintain for 30 minutes, add 31g of 45wt% caustic soda, maintain for 140 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin A3.

[0098] Example I-3

[0099] 152g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 2,2-bis-(4'-hydroxybenzene)-propane and 228g of a mixture of diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and 278g of benzene was added. g, 30g of n-pentanol, heated to 50°C, after the diphenol propane is fully dissolved, 15g of 50wt% caustic soda is added, maintained for 90 minutes, 178g of benzene, 20g of n-pentanol and 25g of 50wt% caustic soda are added, maintained for 120 minutes; 25g of 50wt% caustic soda is added, maintained for 60 minutes, and then 84g of 50wt% caustic soda is added, the temperature is controlled at 60°C, maintained for 180 minutes, washed with water to remove NaCl, recovered the solvent, and obtained epoxy resin A3.

[0100] Example I-4

[0101] 63g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were added to a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the reaction mixture was stirred for 2 hours. Add 106 g of benzene and 71 g of 2-pentanone, heat to 50°C, add 6 g of 45 wt% caustic soda after the diphenol propane is fully dissolved, maintain for 30 minutes, add 106 g of benzene, 71 g of 2-pentanone and 10 g of 45 wt% caustic soda, maintain for 60 minutes; add 12 g of 45 wt% caustic soda, maintain for 60 minutes, add 50 g of 45 wt% caustic soda, maintain for 150 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin A4.

[0102] Example I-5

[0103] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane are put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane is 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane is 1wt%, and the content of diphenol propane is 96wt%. 37g of butanone and 74g of benzene are added, and the mixture is heated to 45°C. After the diphenol propane is fully dissolved, 6g of 60wt% caustic soda is added and maintained for 60 minutes. 37g of butanone, 74g of benzene and 8g of 60wt% caustic soda are added and maintained for 60 minutes. 11g of 60wt% caustic soda is added and maintained for 10 minutes. 35g of 60wt% caustic soda is added and maintained for 120 minutes. The mixture is washed with water to remove NaCl, and the solvent is recovered to obtain epoxy resin A5.

[0104] Example I-6

[0105] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, and the content of diphenol propane was 96wt%. , add 25g of n-butanol and 50g of benzene, heat to 45°C, after the diphenol propane is fully dissolved, add 6g of 60wt% caustic soda, maintain for 60 minutes, add 25g of n-butanol, 50g of benzene and 8g of 60wt% caustic soda, maintain for 60 minutes; add 11g of 60wt% caustic soda, maintain for 10 minutes, add 35g of 60wt% caustic soda, maintain for 120 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin A6.

[0106] Example I-7

[0107] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, and the content of diphenol propane was 96wt%. , add 68g of n-butanol and 68g of benzene, heat to 45°C, after the diphenol propane is fully dissolved, add 5g of 60wt% caustic soda, maintain for 60 minutes, add 68g of n-butanol, 68g of benzene and 6g of 60wt% caustic soda, maintain for 60 minutes; add 10g of 60wt% caustic soda, maintain for 10 minutes, add 35g of 60wt% caustic soda, maintain for 120 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin A7.

[0108] Example I-8

[0109] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was added. 92g of n-pentanol and 46g of 2-pentanone were heated to 45°C. After the diphenol propane was fully dissolved, 5g of 60wt% caustic soda was added and maintained for 60 minutes. Then, 92g of n-pentanol, 46g of 2-pentanone and 6g of 60wt% caustic soda were added and maintained for 60 minutes. 10g of 60wt% caustic soda was added and maintained for 10 minutes. Then, 35g of 60wt% caustic soda was added and maintained for 120 minutes. The NaCl was removed by washing with water and the solvent was recovered to obtain epoxy resin A8.

[0110] Example I-9

[0111] 58 g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114 g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3 wt %, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1 wt %, and the content of diphenol propane was 96 wt %. 86 g of butanone and 86 g of 2-pentanone were added, and the mixture was heated to 45° C. After the diphenol propane was fully dissolved, 56 g of 60 wt % caustic soda was added and maintained for 60 minutes. 86 g of butanone and 86 g of 2-pentanone were added and maintained for 60 minutes. The mixture was washed with water to remove NaCl, and the solvent was recovered to obtain epoxy resin A9.

[0112] Example I-10

[0113] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was added. 86 g of butanone and 86 g of 2-pentanone were heated to 45°C. After the diphenol propane was fully dissolved, 14 g of 60 wt% caustic soda was added and maintained for 60 minutes. 86 g of butanone, 86 g of 2-pentanone and 14 g of 60 wt% caustic soda were added and maintained for 60 minutes. 14 g of 60 wt% caustic soda was added and maintained for 10 minutes. 14 g of 60 wt% caustic soda was added and maintained for 120 minutes. NaCl was removed by washing with water and the solvent was recovered to obtain epoxy resin A10.

[0114] Example I-11

[0115] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was added. 40 g of butanone and 132 g of 2-pentanone were heated to 45°C. After the diphenol propane was fully dissolved, 5 g of 60 wt% caustic soda was added and maintained for 60 minutes. 40 g of butanone, 132 g of 2-pentanone and 6 g of 60 wt% caustic soda were added and maintained for 60 minutes. 10 g of 60 wt% caustic soda was added and maintained for 10 minutes. 35 g of 60 wt% caustic soda was added and maintained for 120 minutes. NaCl was removed by washing with water and the solvent was recovered to obtain epoxy resin A11.

[0116] Example I-12

[0117] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was added. 123 g of butanone and 49 g of 2-pentanone were heated to 45°C. After the diphenol propane was fully dissolved, 5 g of 60 wt% caustic soda was added and maintained for 60 minutes. 123 g of butanone, 49 g of 2-pentanone and 6 g of 60 wt% caustic soda were added and maintained for 60 minutes. 10 g of 60 wt% caustic soda was added and maintained for 10 minutes. 35 g of 60 wt% caustic soda was added and maintained for 120 minutes. NaCl was removed by washing with water and the solvent was recovered to obtain epoxy resin A12.

[0118] Comparative Example I-1

[0119] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane are put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane is 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane is 1wt%, and the content of diphenol propane is 96wt%. 172g of benzene is added, and the mixture is heated to 45°C. After the diphenol propane is fully dissolved, 5g of 60wt% caustic soda is added and maintained for 60 minutes. 172g of benzene and 6g of 60wt% caustic soda are added and maintained for 60 minutes. 10g of 60wt% caustic soda is added and maintained for 10 minutes. 35g of 60wt% caustic soda is added and maintained for 120 minutes. The mixture is washed with water to remove NaCl, and the solvent is recovered to obtain epoxy resin DA1.

[0120] Comparative Example I-2

[0121] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were put into a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and 154g of isopropanol was added. .8g, 17.2g of propylene glycol methyl ether, heated to 45°C, after the diphenol propane is fully dissolved, add 5g of 60wt% caustic soda, maintain for 60 minutes, add 154.8g of isopropanol, 17.2g of propylene glycol methyl ether and 6g of 60wt% caustic soda, maintain for 60 minutes; add 10g of 60wt% caustic soda, maintain for 10 minutes, add 35g of 60wt% caustic soda, maintain for 120 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin DA2.

[0122] Comparative Example I-3

[0123] 58g of epichlorohydrin, 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane, 114g of a mixture of 2,2-bis-(4'-hydroxybenzene)-propane and diphenol propane were added to a reaction kettle, wherein the content of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)-propane was 3wt%, the content of 2,2-bis-(4'-hydroxybenzene)-propane was 1wt%, the content of diphenol propane was 96wt%, and the mixture was stirred for 2 hours. Add 86 g of butanone and 86 g of 2-pentanone, heat to 45°C, add 5 g of 30 wt% caustic soda after the diphenol propane is fully dissolved, maintain for 60 minutes, add 86 g of butanone, 86 g of 2-pentanone and 6 g of 30 wt% caustic soda, maintain for 60 minutes; add 10 g of 30 wt% caustic soda, maintain for 10 minutes, add 35 g of 30 wt% caustic soda, maintain for 120 minutes, wash with water to remove NaCl, recover the solvent, and obtain epoxy resin DA3.

[0124] Comparative Example I-4

[0125] The epoxy resin was prepared according to the traditional process, specifically: 180g of water, 90g of 30wt% caustic soda, and 114g of diphenol propane were put into a reactor, the temperature was controlled at 50°C, maintained for 60 minutes, 61g of epichlorohydrin was added, maintained for 180 minutes, 200g of toluene was added, maintained for 120 minutes, NaCl was removed by washing with water, and the solvent was recovered to obtain epoxy resin DA4. 2200t / t of wastewater was discharged, and the COD of the untreated wastewater was 21300mg / L.

[0126] The number average molecular weight, softening point, melt viscosity, wastewater COD, and TOC of the treated wastewater of the epoxy resins obtained in Examples I-1 to I-12 and Comparative Examples I-1 to I-4 are shown in Table 1.

[0127] Table 1

[0128]

[0129] It can be seen from the results in Table 1 that the preparation method provided by the present invention has less wastewater discharge, lower COD value and TOC value. Specifically, compared with the comparative example I-4 using the traditional process, the wastewater discharge of Examples I-1 to I-12 is reduced by 52wt%, 49wt%, 49wt%, 48wt%, 47wt%, 51wt%, 48wt%, 50wt%, 43wt%, 44wt%, 43wt% and 42wt%, respectively.

[0130] Furthermore, the preparation method provided by the present invention can be used to prepare epoxy resins with different number average molecular weights, and it is difficult to control the number average molecular weight of epoxy resins by traditional processes.

[0131] Example II - Epoxy Resin Composition

[0132] Take 55 parts by weight of the epoxy resins obtained in Examples I-1 to I-12 and Comparative Examples I-1 to I-4 and 45 parts by weight of a phenolic epoxy resin, where the phenolic epoxy resin is an o-cresol epoxy resin, to obtain epoxy resin compositions B1-B12 and DB1-DB4.

[0133] Example III - Curable Composition

[0134] Take 50 parts by weight of the epoxy resin composition of Example II and 7 parts by weight of a curing agent consisting of dicyandiamide, dimethylbenzylamine and dimethylimidazole in a mass ratio of 11:0.3:0.1 to obtain curable compositions C1-C12 and DC1-DC4.

[0135] Test example-epoxy resin products

[0136] The curable composition of Example III was kept at 200°C for 20 minutes and was found to be completely cured after being taken out, thereby obtaining epoxy resin products P1-P12 and DP1-DP4. The bending strength, water absorption, solvent resistance and insulation resistance after immersion in water of the epoxy resin products were tested, and the results are shown in Table 2.

[0137] Table 2

[0138]

[0139]

[0140] *Water absorption refers to the difference in quality before and after water absorption.

[0141] *△W is the mass difference before and after solvent immersion (g).

[0142] It can be seen from the results in Table 2 that, compared with DP1-DP4, the epoxy resin products P1-P12 obtained by curing the curable composition comprising the epoxy resin prepared by the preparation method provided by the present invention have better mechanical properties, anti-corrosion properties and insulation properties.

[0143] In addition, the epoxy resin product obtained by curing the curable composition comprising the epoxy resin prepared by the preparation method provided by the present invention also has excellent mechanical properties, specifically, the bending strength is greater than 400 MPa.

[0144] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing an epoxy resin, characterized in that: The preparation method comprises contacting the bisphenol compound represented by formula (1) and epichlorohydrin with a basic catalyst in the presence of a co-solvent; In formula (1), R1 and R3 are each independently hydrogen, C1-C4 alkyl or substituted alkyl, Br or Cl; R2 is C1-C9 alkylene; The alkaline catalyst is an alkaline solution with a concentration of 35-70wt%; the co-solvent is selected from at least two of C6-C12 non-substituted aromatic compounds, C1-C4 alkyl mono-substituted or poly-substituted aromatic compounds, C2-C11 alcohols, C4-C10 straight-chain or branched ketones, C4-C7 cycloalkanones and C4-C10 esters.

2. The preparation method according to claim 1, wherein The concentration of the alkaline solution is 40-65wt%; Preferably, the mass ratio of the alkaline catalyst to the epichlorohydrin is 0.5-1.5:1; the mass ratio of the co-solvent to the epichlorohydrin is 2-7:1; Preferably, the mass ratio of the bisphenol compound to the epichlorohydrin is 1.3-2:1; Preferably, the alkaline catalyst is selected from at least one of NaOH solution, KOH solution, Ba(OH)2 solution, Ca(OH)2 solution, NaHCO3 solution, Na2CO3 solution and triethanolamine.

3. The preparation method according to claim 1 or 2, wherein: In the presence of a co-solvent, the bisphenol compound represented by formula (1) and epichlorohydrin are contacted with a basic catalyst by adding the basic catalyst and / or the co-solvent to the bisphenol compound represented by formula (1) and epichlorohydrin in batches; Preferably, the time interval between the addition of two adjacent batches is 10-180 minutes; Preferably, the concentration and / or amount of the alkaline catalyst in the latter batch is not less than the concentration and / or amount of the alkaline catalyst in the former batch; Further preferably, the amount of the alkaline catalyst in the latter batch is 10-450 wt % greater than that in the former batch.

4. The preparation method according to claim 3, wherein The alkaline catalyst and / or co-solvent are added to the bisphenol compound represented by formula (1) and epichlorohydrin in 2-4 batches; Preferably, the alkaline catalyst is added to the bisphenol compound represented by formula (1) and epichlorohydrin in four batches, and the third batch of alkaline catalyst is 100-200wt% of the amount of the second batch of alkaline catalyst, and the fourth batch of alkaline catalyst is 300-450wt% of the amount of the third batch of alkaline catalyst.

5. The preparation method according to any one of claims 1 to 4, wherein: The co-solvent is selected from at least two solvents having polarities of 2-5 and 10-28; Preferably, the co-solvent is selected from at least two of benzene, butanol, pentanol, hexanol, 2-pentanone and butanone; Preferably, the co-solvent is selected from at least one of pentanol and benzene in a mass ratio of 1:7-10, hexanol and benzene in a mass ratio of 1:2-3, 2-pentanone and butanone in a mass ratio of 1:0.5-2, benzene and butanone in a mass ratio of 1:0.5-2, benzene and 2-pentanone in a mass ratio of 1:0.5-1.5, n-butanol and benzene in a mass ratio of 1:1.2-3, butanol and benzene in a mass ratio of 1:0.5-2, and pentanol and 2-pentanone in a mass ratio of 1:0.5-1.

6. The preparation method according to any one of claims 1 to 5, wherein: The bisphenol compound is at least one of 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene) propane, 2,2-bis-(4'-hydroxybenzene) propane and diphenol propane; Preferably, based on the total weight of the bisphenol compound, the content of the diphenol propane is 96-98wt%, the content of the 2-(4'-hydroxybenzene)-2-(2'-hydroxybenzene)propane is 1-3wt%, and the content of 2,2-bis-(4'-hydroxybenzene)propane is 0-1wt%.

7. The preparation method according to any one of claims 1 to 6, wherein: The contact conditions include: time of 10-120 min; temperature of 30-70°C.

8. An epoxy resin obtained by the preparation method according to any one of claims 1 to 7.

9. The epoxy resin according to claim 8, wherein The number average molecular weight of the epoxy resin is 300 g / mol-2300 g / mol, preferably 700 g / mol-2300 g / mol; Preferably, the softening point of the epoxy resin is 20-110°C, preferably 60-100°C; Preferably, the melt viscosity of the epoxy resin at 150° C. is 200-4500 mPa·s, preferably 300-2000 mPa·s.

10. An epoxy resin composition, characterized in that The epoxy resin composition comprises the epoxy resin according to claim 8 or 9 and a novolac epoxy resin; Wherein, based on the total weight of the epoxy resin composition, the content of the epoxy resin is 40-60wt%, preferably 50-60wt%, and the content of the phenolic epoxy resin is 40-60wt%, preferably 40-50wt%.

11. A curable resin composition, characterized in that The curable resin composition comprises a first component and a second component, wherein the first component and the second component exist independently; The first component comprises the epoxy resin composition of claim 10; The second component includes a curing agent.

12. The curable resin composition according to claim 11, wherein The amount of the second component is 3-10 parts by weight relative to 100 parts by weight of the first component; Preferably, the curing agent is selected from at least one of dicyandiamide, dimethylimidazole, dimethylbenzylamine, linear phenolic resin and adipic acid dihydrazide; Preferably, the curing agent is dicyandiamide, dimethylimidazole and dimethylbenzylamine, and the mass ratio of the dicyandiamide, dimethylimidazole and dimethylbenzylamine is 20-40:0.2-1:

1.

13. An epoxy resin product, characterized in that: The epoxy resin product is obtained by mixing and curing the curable resin composition according to claim 11 or 12.

14. The epoxy resin product according to claim 13, wherein: The insulation resistance of the epoxy resin product after immersion in water is 50000-500000 MΩ; Preferably, the mass change difference of the epoxy resin product after being immersed in ethyl acetate at 90° C. for 0.5 h is no more than 0.03%.

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