CN112898534B - Epoxy resin, preparation method thereof and application thereof in epoxy terrace - Google Patents

Abstract

The invention provides epoxy resin, a preparation method thereof and application thereof in an epoxy terrace, wherein the preparation method of the epoxy resin directly reacts the residual rectifying still of epoxy chloropropane with bisphenol A without converting substances in the residual rectifying still into epoxy chloropropane for reaction, so that the preparation and purification processes of the epoxy chloropropane are saved, the prepared epoxy resin has low viscosity, can be better applied to the epoxy terrace, and has wide application prospect.

Description

Epoxy resin, preparation method thereof and application thereof in epoxy terrace

Technical Field

The invention relates to the technical field of material synthesis and application, in particular to epoxy resin and a preparation method and application thereof.

Background

Epoxy resins are organic compounds containing more than two epoxy groups in the molecular chain or in the chain ends. The epoxy group is active, so that the epoxy group can react with various curing agents to form a cross-linked insoluble network structure, thereby having excellent cohesiveness and having a pasting effect on the surfaces of various materials.

Bisphenol A epoxy resin, which is diphenol propane epoxy resin prepared from bisphenol A and epoxy chloropropane, is the variety with the largest yield in glycidyl ether epoxy resin. For example, CN109553755a discloses a method for producing bisphenol a type epoxy resin to reduce the consumption of epichlorohydrin and CN109280152A discloses a process for producing high-purity bisphenol a type liquid epoxy resin, which both adopt bisphenol a and epichlorohydrin to prepare epoxy resin. The green development trend of the raw material epoxy chloropropane industry in the process is to adopt a hydrogen peroxide direct oxidation method, methanol is adopted as a solvent in the process, the generated epoxy chloropropane can further react with water or the solvent in the production process to generate impurities containing 1,3-dichloropropanol, 2,3-dichloropropanol, 1-chlorine-propylene glycol, 3-chlorine-1-methoxy-2-propanol, 1,2-epoxy-3-methoxypropane and the like, after most of the epoxy chloropropane is purified by rectification, the rest of the kettle containing 3-chlorine-1-methoxy-2-propanol, 1,3-dichloropropanol, 2,3-dichloropropanol and 1-chlorine-propylene glycol is treated as 'dangerous waste', so that the production cost is increased, and the aim of green production is not met.

CN111607067A discloses a method for synthesizing epoxy resin from epoxy chloropropane distillation kettle residue, the method prepares epoxy resin by firstly saponifying the epoxy chloropropane distillation kettle residue and then saponifying epoxy chloropropane obtained from the distillation kettle residue, but the method still purifies epoxy chloropropane and then prepares epoxy resin, and can not realize the utilization of other impurities in the distillation kettle residue.

Therefore, it is necessary to develop a method for synthesizing an epoxy resin from a still residue containing impurities.

Disclosure of Invention

In order to solve the technical problems, the invention provides the epoxy resin, the preparation method thereof and the application thereof in the epoxy floor, wherein the preparation method of the epoxy resin directly reacts the residual epoxy chloropropane in a rectifying still with the bisphenol A, so that the problem that the existing rectifying still residual treatment needs to firstly convert impurities into epoxy chloropropane, the process is complex, the extraction step of the epoxy chloropropane is not needed, the energy consumption is lower, and the resource utilization of waste liquid is more sufficient.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing an epoxy resin, the method comprising the steps of:

(1) Mixing the epoxy chloropropane and the rest of the epoxy chloropropane in a rectifying still to obtain a pre-reaction liquid;

(2) Mixing the pre-reaction liquid obtained in the step (1), bisphenol A and a condensing agent, and carrying out synthetic reaction to obtain epoxy resin;

the residual epoxy chloropropane rectifying still in the step (1) contains 1,2-epoxy-3-methoxypropane, 1,3-dichloropropanol and 2,3-dichloropropanol.

The invention contains 1,2-epoxy-3-methoxy propane, 1,3-dichloropropanol and 2,3-dichloropropanol, the rest of the rectifying still is mixed with epichlorohydrin and then directly reacts with bisphenol A under the action of a condensing agent, wherein 1,3-dichloropropanol and 2,3-dichloropropanol directly react with bisphenol A under the action of the condensing agent to synthesize epoxy resin, 1,2-epoxy-3-methoxy propane does not participate in the reaction, but does not produce byproducts, and the existence of 1,2-epoxy-3-methoxy propane, 1,3-dichloropropanol and 2,3-dichloropropanol is beneficial to improving the quality of the epoxy resin.

Preferably, the rectification kettle residue of the epichlorohydrin in the step (1) also contains 3-chloro-1-methoxy-2-propanol and/or 1-chloro-propylene glycol.

Preferably, the mass fraction of 2,3-dichloropropanol in the still residue of the rectifying still in step (1) is 15-45%, for example 15%, 19%, 22%, 25%, 29%, 32%, 35%, 39%, 42% or 45% and the like, but is not limited to the recited values, and other values not recited in this range are also applicable.

Preferably, the mass fraction of 1,3-dichlorohydrin in the still bottoms is 50-80%, for example, 50%, 54%, 57%, 60%, 64%, 67%, 70%, 74%, 77%, or 80%, etc., but is not limited to the recited values, and other values not recited in this range are also applicable.

Preferably, the mass fraction of 1,2-epoxy-3-methoxypropane in the still residue is 0.1 to 5%, and may be, for example, 0.1%, 0.7%, 1.2%, 1.8%, 2.3%, 2.9%, 3.4%, 4%, 4.5%, or 5%, but is not limited to the values listed, and other values not listed in this range are also applicable.

Preferably, the mass fraction of 3-chloro-1-methoxy-2-propanol and/or 1-chloro-propanediol in the distillation still residue is 0.1 to 5%, and may be, for example, 0.1%, 0.7%, 1.2%, 1.8%, 2.3%, 2.9%, 3.4%, 4%, 4.5%, or 5%, but is not limited to the above-mentioned values, and other values not listed in this range are also applicable.

Preferably, the rest of the distillation kettle in the step (1) is mixed with epichlorohydrin after distillation.

The pre-reaction liquid is prepared after the distillation, decoking and decoloring of the residue of the rectifying still, which is beneficial to improving the product quality of the epoxy resin.

Preferably, the distillation comprises: the distillation residue is heated and distilled at a temperature of 30 to 80 ℃ and the distillate is collected to obtain the distilled distillation residue, which may be 30 ℃, 36 ℃, 42 ℃, 47 ℃, 53 ℃, 58 ℃, 64 ℃, 69 ℃, 75 ℃ or 80 ℃, but is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.

Preferably, the mass ratio of the epichlorohydrin to the rest of the distillation still in step (1) is 1 to 4:1, and may be, for example, 1:1, 1.4.

The invention directly reacts the pre-reaction liquid containing the rest of the rectifying still with the bisphenol A to prepare the epoxy resin, and the existence of the impurity components can not only not reduce the quality of the epoxy resin but also reduce the viscosity of the prepared epoxy resin.

Preferably, in the step (2), the molar ratio of bisphenol a to epichlorohydrin in the pre-reaction solution is 1:2-10, and may be, for example, 1:2, 1.5, 1:3, 1.

Preferably, the molar ratio of the condensing agent to bisphenol a is 1 to 3:1, and may be, for example, 1:1, 1.3, 1.5, 1.7.

Preferably, the condensing agent comprises an alkaline solution and/or an alkaline solid.

Preferably, a surfactant is also added in step (2).

Preferably, the surfactant is a cationic surfactant.

Preferably, the surfactant comprises any one of benzyl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride or hexadecyl trimethyl ammonium chloride or a combination of at least two of the foregoing.

The amount of the surfactant added is preferably 0.5 to 2% by mass of bisphenol a, and may be, for example, 0.5%, 0.7%, 0.9%, 1%, 1.2%, 1.4%, 1.5%, 1.7%, 1.9%, or 2%, but is not limited to the above-mentioned values, and other values not mentioned in this range are also applicable.

Preferably, the synthesis reaction in step (2) comprises: and mixing the pre-reaction liquid, the bisphenol A and the surfactant, heating under a protective atmosphere, adding a condensing agent after the bisphenol A is dissolved, keeping the temperature to perform a synthesis reaction, and performing solid-liquid separation to obtain the epoxy resin.

Preferably, the protective atmosphere comprises argon and/or nitrogen.

Preferably, the heating temperature is 50 to 75 ℃, for example, 50 ℃, 53 ℃, 56 ℃, 59 ℃,62 ℃, 64 ℃, 67 ℃, 70 ℃, 73 ℃ or 75 ℃, but not limited to the cited values, and other values not listed in the range are also applicable.

Preferably, the synthesis reaction temperature is 55-65 ℃, for example, 55 ℃, 57 ℃, 58 ℃, 59 ℃,60 ℃, 61 ℃,62 ℃, 63 ℃, 64 ℃ or 65 ℃, but not limited to the cited values, in the scope of other values are also applicable.

Preferably, the pressure of the synthesis reaction is 0 to-0.1 MPa, and may be, for example, 0MPa, -0.02MPa, -0.03MPa, -0.05MPa, -0.08MPa, -0.09MPa or-0.1 MPa, but is not limited to the values listed above, and other values not listed above within this range are also applicable.

Preferably, the time of the synthesis reaction is 3 to 8 hours, for example, 3 hours, 3.4 hours, 4 hours, 4.4 hours, 5 hours, 5.4 hours, 5.7 hours, 6 hours, 6.5 hours, 7 hours, 7.4 hours or 8 hours, etc., but not limited to the recited values, and other values not recited in the range are also applicable.

Preferably, the addition of the condensing agent is carried out in 1 to 3 batches, which may be, for example, 1,2 or 3 batches.

As a preferable technical scheme of the invention, the preparation method comprises the following steps:

(1) Heating and distilling the residual distillation still of the epoxy chloropropane at the temperature of 30-80 ℃, and collecting fractions to obtain the distilled residual distillation still; mixing epoxy chloropropane and the rest of the rectifying still according to the mass ratio of 1-4:1 to obtain a pre-reaction liquid;

the rest of the epichlorohydrin rectifying still contains 1,2-epoxy-3-methoxypropane with the mass fraction of 0.1-5%, 1,3-dichloropropanol with the mass fraction of 50-80%, 2,3-dichloropropanol with the mass fraction of 15-45% and 3-chlorine-1-methoxy-2-propanol and/or 1-chlorine-propylene glycol optionally;

(2) Mixing the pre-reaction solution obtained in the step (1), bisphenol A and a surfactant, wherein the molar ratio of bisphenol A to epichlorohydrin in the pre-reaction solution is 1:2-10, the addition amount of the surfactant is 0.5-2% of the mass of bisphenol A, heating to 50-75 ℃ under a protective atmosphere, dissolving bisphenol A, adding a condensing agent for 1-3 times, wherein the condensing agent comprises an alkaline solution and/or an alkaline solid, the molar ratio of the condensing agent to bisphenol A is 1-3.

According to the invention, the epoxy chloropropane and the rest of the rectifying still are mixed and then react with the bisphenol A, so that the uniform mixing of all components in the rest of the rectifying still and the epoxy chloropropane is facilitated, and the prepared epoxy resin has better quality.

In a second aspect, the present invention provides an epoxy resin obtained by the method for preparing an epoxy resin according to the first aspect.

The epoxy resin prepared by the invention has low viscosity, high epoxy value and wide application prospect.

Preferably, the epoxy resin has a viscosity of 12700cps or less, and may be, for example, 10000cps, 10300cps, 10600cps, 10900cps, 11200cps, 11500cps, 11800cps, 12100cps, 12400cps, 12700cps, etc., but is not limited to the enumerated values, and other non-enumerated values within this range are also applicable.

Preferably, the epoxy value of the epoxy resin is not less than 0.40g epoxy group/100 g, and may be, for example, 0.40 epoxy group/100 g, 0.42 epoxy group/100 g, 0.45 epoxy group/100 g, 0.46 epoxy group/100 g, 0.50 epoxy group/100 g, 0.51 epoxy group/100 g or 0.52 epoxy group/100 g, but not limited to the above-mentioned values, and other values not listed in the range are also applicable.

In a third aspect, the present invention provides a use of the epoxy resin of the first aspect in an epoxy floor.

The method for preparing the epoxy terrace by using the epoxy resin is not particularly limited, the steps or modes which can realize the operation and are conventionally adopted by the technical personnel in the field can be adopted, and the method can be properly adjusted on the conventional mode according to the actual situation, so that the method is not particularly limited. Preferably, the epoxy floor is obtained by adding a proper amount of curing agent or initiator into the synthesized epoxy resin according to the existing mature method and curing.

The epoxy resin prepared by the invention has the advantages of low viscosity, good fluidity and the like, and simultaneously, the invention recycles byproducts in the production, has simple synthesis process, and accords with the purposes of green production and changing waste into valuable.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) In the preparation method of the epoxy resin, the raw materials of the pre-reaction liquid are epichlorohydrin and impurities left in a rectifying still generated in the process of producing the epichlorohydrin; the popularization of the method can directly use the epoxy chloropropane which is not rectified for the synthesis of the special epoxy resin, thereby further reducing the production cost while improving the product value;

(2) The impurities in the residue of the rectifying still of the preparation method of the epoxy resin provided by the invention react with bisphenol A in one step under the action of the condensing agent to generate the special liquid epoxy resin with low viscosity and good fluidity, wherein the viscosity is less than or equal to 12637cps, and can be less than or equal to 11643cps under better conditions;

(3) The epoxy resin provided by the invention has low viscosity and high epoxy value, the epoxy value is more than 0.40g epoxy group/100 g, and the epoxy resin can be applied to various fields such as epoxy terraces and the like and has wide application prospect.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

1. Examples of the embodiments

Example 1

This embodiment provides a method for preparing an epoxy resin, including the steps of:

(1) Heating and distilling the distillation still residue of 120g of epoxy chloropropane at the temperature of 60 ℃, collecting fractions at the temperature of 60 ℃ to obtain 100g of distilled distillation still residue (2,3-dichloropropanol: 15wt%,1,3-dichloropropanol: 80wt%,1,2-epoxy-3-methoxypropane: 0.2wt%, 3-chloro-1-methoxy-2-propanol: 0.8wt%, 3-chloro-propanediol: 4 wt%); mixing 400g of epichlorohydrin with the rest of the rectifying still according to the mass ratio of 4:1 to obtain a pre-reaction liquid;

(2) Mixing 500g of the pre-reaction liquid in the step (1), 195.8g of bisphenol A and 2g of benzyltrimethylammonium chloride, stirring under a nitrogen atmosphere, heating to 55 ℃, slowly dropwise adding 10.32g of NaOH with the content of 50wt% after the bisphenol A is dissolved, controlling the reaction temperature to be 56 ℃, keeping the temperature at normal pressure for 3 hours after dropwise adding is finished, adjusting the kettle pressure to-0.08 MPa, heating the reaction to 62 ℃, slowly dropwise adding 113.3g of NaOH with the content of 50wt% after the reaction is finished within 3 hours, keeping the temperature at 65 ℃ for 1 hour, carrying out a synthetic reaction, and filtering and distilling under reduced pressure to obtain the epoxy resin.

Example 2

This example provides a process for producing an epoxy resin, which is the same as in example 1 except that the 65 ℃ fraction was collected in step (1) to obtain 100g of distilled still bottoms (2,3-dichloropropanol: 35wt%,1,3-dichloropropanol: 60wt%,1,2-epoxy-3-methoxypropane: 0.15wt%, 3-chloro-1-methoxy-2-propanol: 1.35wt%, 3-chloro-propanediol: 3.5 wt%).

Example 3

This example provides a method for producing an epoxy resin, which is the same as in example 1 except that the mass ratio of epichlorohydrin to the remainder of the still for rectification in step (1) is 1.5.

Example 4

This example provides a process for producing an epoxy resin, which was the same as that of example 1 except that the mass of bisphenol a in step (2) was 151.7 g.

Example 5

This example provides a method for preparing an epoxy resin, which is the same as that of example 1 except that "benzyltrimethylammonium chloride" was replaced with "cetyltrimethylammonium chloride" in step (2).

Example 6

This example provides a process for producing an epoxy resin, which was the same as in example 1 except that the reaction temperature and time in step (2) were adjusted.

Specifically, the step (2) is to mix 500g of the pre-reaction liquid obtained in the step (1), 195.8g of bisphenol A and 2g of benzyltrimethylammonium chloride, stir the mixture in a nitrogen atmosphere, heat the mixture to 58 ℃, slowly add 10.32g of NaOH with the content of 50wt% after the bisphenol A is dissolved, control the reaction temperature to 60 ℃, keep the temperature for 2 hours under normal pressure after the addition is finished, adjust the kettle pressure to-0.08 MPa, heat the reaction to 62 ℃, slowly add 113.3g of NaOH with the content of 50wt% in a dropwise manner within 3 hours, keep the temperature for 2 hours at 65 ℃, perform a synthetic reaction, and obtain the epoxy resin through filtration and reduced pressure distillation.

Example 7

This example provides a method for preparing an epoxy resin, which is the same as in example 1 except that the alkali solution is added at one time in step (2).

Specifically, the step (2) is to mix 500g of the pre-reaction liquid in the step (1), 195.8g of bisphenol A and 2g of benzyltrimethylammonium chloride, stir in a nitrogen atmosphere, heat to 55 ℃, adjust the kettle pressure to-0.08 MPa after the bisphenol A is dissolved, slowly add 123.6g of NaOH with the content of 50wt% dropwise, control the reaction temperature to be 62 ℃, finish dropwise addition within 3 hours, keep the temperature at 62 ℃ for 3 hours, perform synthetic reaction, and obtain the epoxy resin through filtration and reduced pressure distillation.

Example 8

This embodiment provides a method for preparing an epoxy resin, including the steps of:

(1) Heating and distilling the distillation kettle residue of 110g of epoxy chloropropane at the temperature of 80 ℃, collecting fractions at the temperature of 80 ℃ to obtain 100g of distilled distillation kettle residue (2,3-dichloropropanol: 40wt%,1,3-dichloropropanol: 50wt%,1,2-epoxy-3-methoxypropane: 5wt%, 3-chloro-1-methoxy-2-propanol: 1.5wt%, 3-chloro-propanediol: 3.5 wt%); mixing 100g of epichlorohydrin with the rest of the rectifying still according to the mass ratio of 1:1 to obtain a pre-reaction liquid;

(2) Mixing 200g of the pre-reaction liquid in the step (1), 200g of bisphenol A and 1.4g of benzyltrimethylammonium chloride, stirring under an argon atmosphere, heating to 75 ℃, slowly dropwise adding 70g of NaOH with the content of 40wt% after the bisphenol A is dissolved, controlling the reaction temperature to be 55 ℃, keeping the temperature for 2 hours at normal pressure after the dropwise adding is finished, adjusting the kettle pressure to-0.05 MPa, heating the reaction to 65 ℃, slowly dropwise adding 93g of NaOH with the content of 45wt% after the reaction is finished, keeping the temperature for 2 hours at 60 ℃, carrying out synthetic reaction, and filtering and distilling under reduced pressure to obtain the epoxy resin.

Example 9

This embodiment provides a method for preparing an epoxy resin, including the steps of:

(1) Heating and distilling the distillation still residue of 120g of epoxy chloropropane at 45 ℃, collecting the fraction at 45 ℃ to obtain 100g of distilled distillation still residue (2,3-dichloropropanol: 25wt%,1,3-dichloropropanol: 70wt%,1,2-epoxy-3-methoxypropane: 1.5wt%, 3-chloro-1-methoxy-2-propanol: 0.5wt%, 3-chloro-propanediol: 3 wt%); mixing 300g of epichlorohydrin with the rest of the rectifying still according to the mass ratio of 3:1 to obtain a pre-reaction liquid;

(2) Mixing 400g of the pre-reaction liquid in the step (1), 185g of bisphenol A and 4g of benzyltrimethylammonium chloride, stirring under a nitrogen atmosphere, heating to 50 ℃, slowly dropwise adding 93g of NaOH with the content of 35wt% after the bisphenol A is dissolved, controlling the reaction temperature to be 57 ℃, keeping the temperature at normal pressure for 3h after the dropwise adding is finished, adjusting the kettle pressure to-0.1 MPa, heating to 65 ℃ for reaction, slowly dropwise adding 139g of NaOH with the content of 35wt% after the dropwise adding is finished within 2h, keeping the temperature at 65 ℃ for 2h, carrying out synthetic reaction, and filtering and distilling under reduced pressure to obtain the epoxy resin.

Example 10

This example provides a process for producing an epoxy resin, which is the same as in example 1 except that the temperature of the thermal distillation in step (1) was 42 ℃ and a fraction at 42 ℃ was collected to obtain 100g of distilled still bottoms (2,3-dichloropropanol: 20wt%,1,3-dichloropropanol: 75wt%,1,2-epoxy-3-methoxypropane: 0.5wt%, 3-chloro-1-methoxy-2-propanol: 1wt%, 3-chloro-propanediol: 3.5 wt%).

Example 11

This example provides a process for producing an epoxy resin, which is the same as in example 1 except that the temperature of the thermal distillation in step (1) was 85 ℃ and a fraction at 85 ℃ was collected to obtain 100g of distilled still bottoms (2,3-dichloropropanol: 30wt%,1,3-dichloropropanol: 65wt%,1,2-epoxy-3-methoxypropane: 0.3wt%, 3-chloro-1-methoxy-2-propanol: 0.7wt%, 3-chloro-propanediol: 4 wt%).

2. Comparative example

Comparative example 1

This comparative example provides a process for the preparation of an epoxy resin, which is identical to that of example 1, except that step (1) is not carried out, and step (2) is carried out by directly using 500 epichlorohydrin as the pre-reaction liquid.

Comparative example 2

This comparative example provides a method of preparing an epoxy resin, which is the method provided in example 6 of CN111607067 a.

3. Test and results

The properties of the specialty epoxy resins prepared using the above examples were tested.

Method for measuring viscosity: reference is made to GB12007.4.

Epoxy value test method: according to the GB/T1677-2008 (hydrochloric acid-acetone method) standard for measuring the epoxy value of the plasticizer, sodium hydroxide standard solution is adopted to titrate an acetone hydrochloride solution in which an epoxy resin sample is dissolved, and a cresol red and thymol blue mixed indicator is used as an indicator.

The test results of the above examples and comparative examples are shown in table 1.

TABLE 1

From table 1, the following points can be seen:

(1) It can be seen from the comprehensive examples 1-11 that, in the examples 1-11, the pre-reaction liquid mixed with epichlorohydrin after the distillation of epichlorohydrin is used to directly react with bisphenol a to generate epoxy resin, the process is simple, the by-product in the production of epichlorohydrin can be recycled, the environmental pressure is relieved, the epoxy value of the prepared epoxy resin is more than 0.40g epoxy group/100 g, the viscosity of the liquid epoxy resin is less than or equal to 12637cps, and can be less than or equal to 11643cps under better conditions, and the epoxy resin has good industrial application value;

(2) It can be seen from the combination of examples 1 to 2 and examples 10 to 11 that the change of the residual components in the rectifying still has little influence on the product quality of the epoxy resin, and the epoxy resin with excellent product quality can be obtained;

(3) It can be seen from the combination of examples 1,3 and 1.5 that the mass ratio of the epichlorohydrin to the residue of the rectification kettle in examples 1 and 3 is 4:1 and 1.5, respectively, the viscosity of the epoxy resin in examples 1 and 3 is 12305cps and 11643cps, respectively, the epoxy value can also reach 0.486g epoxy group/100 g and 0.503g epoxy group/100 g, while the viscosity of the epoxy resin in comparative example 1 is up to 12931cps and all the epoxy chloropropane is required to be used, and the cost is high, thereby showing that the invention adopts the direct reaction after the residue of the rectification kettle is mixed with the epoxy chloropropane, the presence of organic alcohol impurities in the residue of the rectification kettle can reduce the viscosity of the epoxy resin product to obtain the epoxy resin with low viscosity, the cost is significantly reduced and the viscosity of the epoxy resin is reduced;

(4) It can be seen from the synthesis of example 11 and comparative example 2 that example 11 employs a method in which the distillation still residue is directly reacted with bisphenol a, and compared with comparative example 2 in which the distillation still residue is saponified and vacuum distilled and separated to be converted into epichlorohydrin, in example 11, no more distillation steps are required, the process is simpler, the viscosity is 11235cps, in comparative example 2, the process is more complicated, the energy consumption is higher, liquid-liquid separation after saponification is accompanied by waste liquid generation, and the viscosity of the prepared epoxy resin is 11805cps, thereby indicating that the method for directly reacting the distillation still residue provided by the present invention not only saves the process, but also further reduces the viscosity of the epoxy resin, and widens the application prospect of the epoxy resin.

In conclusion, the method for preparing the epoxy resin from the by-product produced from the epichlorohydrin can recycle the by-product, and the prepared special epoxy resin has the epoxy value of more than 0.40g epoxy group/100 g and the viscosity of less than or equal to 12637cps, meets the market demand and can be better applied to the field of epoxy terraces.

The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (21)

1. The preparation method of the epoxy resin is characterized by comprising the following steps of:

(1) Mixing the residual of the distillation kettle of the epoxy chloropropane and the epoxy chloropropane, distilling the residual of the distillation kettle, and mixing the distilled residual of the distillation kettle with the epoxy chloropropane, wherein the mass ratio of the epoxy chloropropane to the residual of the distillation kettle is 1-4:1, and obtaining a pre-reaction liquid;

(2) Mixing the pre-reaction liquid obtained in the step (1), bisphenol A and a condensing agent, and carrying out synthetic reaction to obtain epoxy resin;

the residual epoxy chloropropane rectifying still in the step (1) contains 1,2-epoxy-3-methoxypropane, 1,3-dichloropropanol and 2,3-dichloropropanol, the mass fraction of 2,3-dichloropropanol in the residual epoxy chloropropane rectifying still is 15-45%, and the mass fraction of 1,3-dichloropropanol is 50-80%.

2. The process according to claim 1, wherein the distillation residue of epichlorohydrin in step (1) further contains 3-chloro-1-methoxy-2-propanol and/or 1-chloro-propylene glycol.

3. The preparation method according to claim 1, wherein the mass fraction of 1,2-epoxy-3-methoxypropane in the distillation still residue in step (1) is 0.1 to 5%.

4. The preparation method according to claim 2, wherein the mass fraction of 3-chloro-1-methoxy-2-propanol and/or 1-chloro-propylene glycol in the still residue in the step (1) is 0.1 to 5%.

5. The production method according to claim 1, wherein the distillation in step (1) comprises: and heating and distilling the distillation kettle residue at the temperature of 30-80 ℃, and collecting fractions to obtain the distilled distillation kettle residue.

6. The method according to claim 1, wherein the molar ratio of bisphenol A to epichlorohydrin in the pre-reaction solution in step (2) is 1:2 to 10.

7. The method according to claim 1, wherein the molar ratio of the condensing agent to the bisphenol A is 1 to 3:1.

8. The production method according to claim 1, wherein the condensing agent includes an alkaline solution and/or an alkaline solid.

9. The method according to claim 1, wherein a surfactant is further added in the step (2).

10. The method according to claim 9, wherein the surfactant is a cationic surfactant.

11. The method of claim 9, wherein the surfactant comprises any one of benzyl trimethyl ammonium chloride, octadecyl trimethyl ammonium chloride, or hexadecyl trimethyl ammonium chloride, or a combination of at least two thereof.

12. The method according to claim 9, wherein the surfactant is added in an amount of 0.5 to 2% by mass based on the bisphenol A.

13. The method according to claim 9, wherein the synthesis reaction in step (2) comprises: mixing the pre-reaction liquid, bisphenol A and a surfactant, heating under a protective atmosphere, adding a condensing agent after the bisphenol A is dissolved, carrying out heat preservation for synthetic reaction, and carrying out solid-liquid separation to obtain the epoxy resin.

14. The method of claim 13, wherein the protective atmosphere comprises argon and/or nitrogen.

15. The method of claim 13, wherein the heating temperature is 50 to 75 ℃.

16. The method according to claim 13, wherein the incubation temperature of the synthesis reaction is 55 to 65 ℃.

17. The method according to claim 13, wherein the pressure of the synthesis reaction is 0 to-0.1 MPa.

18. The method according to claim 13, wherein the synthesis reaction time is 3 to 8 hours.

19. The method according to claim 13, wherein the condensing agent is added in 1 to 3 batches.

20. The method as claimed in claim 1, wherein the viscosity of the epoxy resin of step (2) is 12700cps or less.

21. The method according to claim 1, wherein the epoxy value of the epoxy resin in the step (2) is not less than 0.40g epoxy group/100 g.