A method for preparing an epoxy resin water-based emulsion by phase inversion

Abstract

The application discloses a method for preparing an epoxy resin water-based emulsion by phase inversion, and comprises the following steps: (1) mixing epoxy resin A with epoxy resin B, and adding emulsifier C and emulsifier D into the epoxy resin mixture; (2) adding organic solvent ethylene glycol monobutyl ether, propylene glycol methyl ether or ethylene glycol tert-butyl ether into the epoxy resin and emulsifier mixture, and heating the mixture to a molten state; (3) stirring the molten mixture; (4) adding water into the mixture to perform titration, and performing phase inversion treatment; and (5) filtering after being cooled to room temperature to prepare the water-based epoxy emulsion. The two specific polyether-modified non-ionic epoxy resin emulsifiers C and D are added into the mixture of the epoxy resin A and B to perform phase inversion synthesis, the obtained water-based epoxy emulsion has high viscosity and good mechanical stability, can be applied to industrial large-scale production, has wide application prospect, and is favorable for popularization and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical coatings, in particular to a method for preparing an epoxy resin water-based emulsion by phase inversion. BACKGROUND

[0002] The water-based epoxy emulsion is a stable dispersion system obtained by dispersing epoxy resin in the form of particles or droplets in a medium with water as the continuous phase. Compared with traditional epoxy resin, it not only has good operation performance, but also meets the current environmental protection requirements. In addition, the outstanding advantages of water-based epoxy resin also lie in that it can be cured in a humid environment and at room temperature, and has reasonable curing time and high crosslinking density.

[0003] The phase inversion method is a relatively effective method for preparing polymer resin emulsion. Almost all polymer resins can be used to prepare corresponding emulsions by physical emulsification with the help of added emulsifiers. The epoxy resin and the emulsifier are uniformly mixed under shearing action by adopting the phase inversion method. With the increase of water in the system, the system undergoes a transition from water-in-oil to oil-in-water. After dilution, the epoxy emulsion is prepared. The phase inversion method for preparing the epoxy emulsion has the advantages of simple process and low cost, and is an ideal method for preparing the epoxy emulsion compared with other methods, which has important practical significance.

[0004] However, the water-based epoxy emulsion synthesized by the phase inversion method has many defects, such as large particle size and poor stability, which brings great difficulties to industrial mass production. In addition, the water-based epoxy emulsion synthesized by the phase inversion method has low viscosity and poor sag resistance, which seriously affects its application performance. Chinese invention patent CN109384941A introduces nonionic polyether chain segments into the main chain of epoxy resin, adds a mixture of water and organic solvent, a surfactant and an additive, and stirs at a predetermined temperature to finally prepare a water-based epoxy emulsion with a viscosity of 100-300. However, the water-based epoxy emulsion with a viscosity of 100-300 has poor sag resistance and low mechanical stability, which seriously affects its application performance. Therefore, it is urgent to develop a new method for preparing an epoxy resin water-based emulsion by phase inversion to solve the technical problems of low viscosity and poor stability of the synthesized emulsion in the prior art.

[0005] In view of this, the present application is proposed. SUMMARY

[0006] The purpose of the present application is to provide a method for preparing an epoxy resin water-based emulsion by phase inversion. Two specific polyether-modified nonionic epoxy resin emulsifiers C and D are added to the mixture of epoxy resins A and B for phase inversion synthesis, and the obtained water-based epoxy emulsion has high viscosity and good mechanical stability, which can be applied to industrial mass production and has broad application prospects, and is conducive to popularization and application.

[0007] To achieve the above object, the present application provides a method for preparing water-based emulsion of epoxy resin by phase inversion, comprising the following steps:

[0008] (1) mixing epoxy resin A and epoxy resin B with a mass ratio of 4-9:1, adding emulsifier C and emulsifier D with a mass ratio of 1-2:1 into the mixture of epoxy resin, the total amount of emulsifier C and emulsifier D being 0.15-0.20 times the total mass of epoxy resin A and epoxy resin B, the epoxy resin A being E20 or E51, the epoxy resin B being E44 or E51, the emulsifier C and D being respectively non-ionic epoxy resin emulsifier synthesized by polyene phenol modified polyoxyethylene ether and polyoxyethylene modified non-ionic epoxy resin emulsifier;

[0009] (2) adding organic solvent ethylene glycol monobutyl ether, propylene glycol methyl ether or ethylene glycol tert-butyl ether into the mixture of epoxy resin and emulsifier, and heating the mixture to a molten state;

[0010] (3) stirring the mixture in a molten state;

[0011] (4) adding water to the mixture for titration, and performing phase inversion treatment;

[0012] (5) filtering after cooling to room temperature to prepare water-based epoxy emulsion.

[0013] Preferably, in the step (2), the added amount of organic solvent is 0.06-0.15 times the total mass of epoxy resin.

[0014] Preferably, in the step (2), the heating temperature is 70-80℃.

[0015] Preferably, in the step (3), the stirring temperature is 60-70℃, the stirring speed is 1500-2000 rpm, and the stirring time is 15-20 min.

[0016] Preferably, in the step (4), the amount of water is 186-237 g, the titration speed is 5-15 g / min, the phase inversion treatment temperature is 70-80℃, and the emulsification time is 1.5-2 h.

[0017] Preferably, in the step (5), the solid content of the prepared water-based epoxy emulsion is 50-55%.

[0018] Preferably, in the step (1), the mass ratio of epoxy resin A to epoxy resin B is 23:2, the mass ratio of emulsifier C to emulsifier D is 3:2, and the total amount of emulsifier C and emulsifier D is 0.09 times the total mass of epoxy resin A and epoxy resin B.

[0019] Preferably, the amount of the organic solvent added in step (2) is 0.1 times the total mass of the epoxy resin.

[0020] The method for preparing the water-based emulsion of the epoxy resin by phase inversion has the following beneficial effects.

[0021] The inventor of the present application abandoned the traditional method of phase inversion synthesis using a single resin and a single emulsifier, and through a large number of experiments, it was surprisingly found that the mixture of epoxy resins A and B was added with two specific polyether-modified non-ionic epoxy resin emulsifiers C and D for phase inversion synthesis, and the interaction between the components could significantly improve the viscosity and mechanical stability of the water-based epoxy emulsion. In particular, emulsifiers C and D have good synergistic effect in improving the viscosity and stability of the synthesized emulsion, and unexpected technical effects are produced. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with specific examples to help understand the content of the present application.

[0023] The method for preparing the water-based emulsion of the epoxy resin by phase inversion provided by the present application comprises the following steps:

[0024] (1) Mix epoxy resin A and epoxy resin B in a mass ratio of 4-9:1, and add emulsifier C and emulsifier D in a mass ratio of 1-2:1 to the mixture of epoxy resins, the total amount of emulsifier C and emulsifier D being 0.15-0.20 times the total mass of epoxy resin A and epoxy resin B, the epoxy resin A being E20 or E51, the epoxy resin B being E44 or E51, the emulsifier C and D being non-ionic epoxy resin emulsifiers synthesized by polyene phenol modified polyoxyethylene ether and polyoxyethylene modified non-ionic epoxy resin emulsifier respectively; the mass ratio of epoxy resin A to epoxy resin B is 23:2, the mass ratio of emulsifier C to emulsifier D is 3:2, and the total amount of emulsifier C and emulsifier D is 0.09 times the total mass of epoxy resin A and epoxy resin B.

[0025] (2) Add an organic solvent, ethylene glycol monobutyl ether, propylene glycol methyl ether or ethylene glycol tert-butyl ether, to the mixture of epoxy resin and emulsifier, and heat the mixture to a molten state; the heating temperature is 70-80℃. The amount of the organic solvent added is 0.06-0.15 times the total mass of the epoxy resin. Preferably, the amount of the organic solvent added is 0.1 times the total mass of the epoxy resin.

[0026] (3) Stir the molten mixture; the stirring temperature is 60-70℃, the stirring speed is 1500-2000 revolutions per minute, and the stirring time is 15-20 minutes.

[0027] (4) water is added to the mixture for titration, and phase inversion treatment is performed; the water amount is 186-237 g, the titration speed is 5-15 g / min, the phase inversion treatment temperature is 70-80 °C, and the emulsification process time is 1.5-2 h.

[0028] (5) filtration is performed after being cooled to room temperature to prepare an aqueous epoxy emulsion. The solid content of the prepared aqueous epoxy emulsion is 50-55%.

[0029] Example 1

[0030] (1) 190 g of epoxy resin A E20 is mixed with 10 g of epoxy resin B E51, 20 g of emulsifier C and 20 g of emulsifier D are mixed and then added to the epoxy resin mixture, wherein the emulsifiers C and D are respectively a non-ionic epoxy resin emulsifier synthesized by polyene phenol modified polyoxyethylene ether and a non-ionic epoxy resin emulsifier modified by polyoxyethylene;

[0031] (2) 12 g of propylene glycol methyl ether is added to the mixture of the epoxy resin and the emulsifier, and the mixture is heated to a molten state at 80 °C;

[0032] (3) the mixture is stirred at 60 °C, the stirring speed is 2000 rpm, and the stirring time is 15 min;

[0033] (4) 186 g of water is added for titration at 80 °C, the titration speed is 15 g / min, and the emulsification process time is 1.5 h;

[0034] (5) filtration is performed after being cooled to room temperature to prepare an aqueous epoxy emulsion with a solid content of 55%.

[0035] Example 2

[0036] (1) 200 g of epoxy resin A E51 is mixed with 50 g of epoxy resin B E44, and then 25 g of emulsifier C and 12.5 g of emulsifier D are added, wherein the emulsifiers C and D are respectively a non-ionic epoxy resin emulsifier synthesized by polyene phenol modified polyoxyethylene ether and a non-ionic epoxy resin emulsifier modified by polyoxyethylene;

[0037] (2) 37.5 g of ethylene glycol tert-butyl ether is added to the mixture of the epoxy resin and the emulsifier, and the mixture is heated to a molten state at 70 °C;

[0038] (3) the molten state is stirred at 70 °C, the stirring speed is 1500 rpm, and the stirring time is 20 min;

[0039] (4) 237 g of water is added for titration at 70 °C, the titration speed is 5 g / min, and the phase inversion time is 2 h;

[0040] (5) cooled to room temperature and filtered to produce an aqueous epoxy emulsion having a solid content of 50%.

[0041] Example 3

[0042] (1) 230 g of epoxy resin A E20 was mixed with 20 g of epoxy resin B E44, and 25.5 g of emulsifier C and 17 g of emulsifier D were added to the mixture, the emulsifier C and D being a non-ionic epoxy resin emulsifier synthesized from a polyene phenol modified polyoxyethylene ether and a non-ionic epoxy resin emulsifier modified by polyoxyethylene, respectively;

[0043] (2) 25 g of propylene glycol methyl ether was added to the mixture of epoxy resin and emulsifier, and the mixture was heated to a molten state at 75°C;

[0044] (3) the molten state was stirred at 65°C at a stirring speed of 1750 rpm for 17.5 min;

[0045] (4) 212 g of water was added to the mixture at 75°C at a titration speed of 10 g / min, and the phase inversion time was 1.75 h;

[0046] (5) cooled to room temperature and filtered to produce an aqueous epoxy emulsion having a solid content of 52.5%.

[0047] Comparative Example 1

[0048] (1) 190 g of epoxy resin A E20 was mixed with 10 g of epoxy resin B E51, and 40 g of emulsifier C was added to the mixture of epoxy resin, the emulsifier C being a non-ionic epoxy resin emulsifier synthesized from a polyene phenol modified polyoxyethylene ether;

[0049] (2) 12 g of propylene glycol methyl ether was added to the mixture of epoxy resin and emulsifier, and the mixture was heated to a molten state at 80°C;

[0050] (3) the mixture was stirred at 60°C at a stirring speed of 2000 rpm for 15 min;

[0051] (4) 186 g of water was added to the mixture at 80°C at a titration speed of 15 g / min, and the emulsification time was 1.5 h;

[0052] (5) cooled to room temperature and filtered to produce an aqueous epoxy emulsion.

[0053] Comparative Example 2

[0054] (1) 190 g of epoxy resin A E20 was mixed with 10 g of epoxy resin B E51, and 40 g of emulsifier D was added to the mixture of epoxy resin, the emulsifier D being a non-ionic epoxy resin emulsifier modified by polyoxyethylene;

[0055] (2) 12 g of propylene glycol methyl ether was added to the mixture of epoxy resin and emulsifier, and the mixture was heated to a molten state at 80°C;

[0056] (3) The mixture was stirred at 60°C at a stirring speed of 2000 rpm for 15 min;

[0057] (4) 186 g of water was added dropwise at 80°C at a dropping speed of 15 g / min, and the emulsification process lasted for 1.5 h;

[0058] (5) Filtration was performed after being cooled to room temperature to obtain the waterborne epoxy emulsion.

[0059] Implementation effect

[0060] The emulsions of Examples 1-3 and Comparative Example 1-2 were subjected to emulsion performance testing according to the following method, and the test results are shown in Table 1.

[0061] Viscosity: The viscosity of the emulsion was tested according to the national standard GB / T11175-2002.

[0062] Mechanical stability: The mechanical stability of the emulsion was tested according to the national standard GB / T11175-2002.

[0063] Table 1: Emulsion performance test results

[0064]

[0065] As can be seen from Table 1, the mixture of epoxy resins A and B was added with two specific polyether-modified non-ionic epoxy resin emulsifiers C and D for phase inversion synthesis, and the interaction between the components can significantly improve the viscosity and mechanical stability of the waterborne epoxy emulsion. Since the viscosity and mechanical stability of the waterborne epoxy emulsion of Examples 1-3 are significantly better than those of Comparative Example 1-2, it is proved that the emulsifiers C and D have good synergistic effect in improving the viscosity and stability of the synthesized emulsion, and the invention produces unexpected technical effects.

[0066] The specific examples are applied in this paper to elaborate the inventive concept in detail, and the above examples are only used to help understand the core idea of the invention. It should be noted that any obvious modification, equivalent replacement or other improvement made by those skilled in the art without departing from the inventive concept should be included in the protection scope of the invention.

Claims

1. A process for the preparation of an aqueous-based emulsion of an epoxy resin by phase inversion, characterized in that, The method comprises the following steps: (1) mixing epoxy resin A and epoxy resin B with a mass ratio of 4-19:1, adding emulsifier C and emulsifier D with a mass ratio of 1-2:1 into the epoxy resin mixture, the total amount of emulsifier C and emulsifier D being 0.15-0.20 times the total mass of epoxy resin A and epoxy resin B, the epoxy resin A being E20 or E51, the epoxy resin B being E44 or E51, the emulsifier C and D being non-ionic epoxy resin emulsifiers synthesized by polyene phenol modified polyoxyethylene ether and polyoxyethylene modified non-ionic epoxy resin emulsifier respectively; (2) adding organic solvent ethylene glycol monobutyl ether, propylene glycol methyl ether or ethylene glycol tert-butyl ether into the epoxy resin and emulsifier mixture, heating the mixture to a molten state, the amount of organic solvent being 0.06-0.15 times the total mass of epoxy resin; (3) stirring the molten mixture; (4) adding water to the mixture for titration, and performing phase inversion treatment; (5) filtering after cooling to room temperature to prepare an aqueous epoxy emulsion, the solid content of the prepared aqueous epoxy emulsion being 50-55%.

2. The method of claim 1, wherein the epoxy resin water-based emulsion is prepared by phase inversion. In the step (2), the heating temperature is 70-80℃.

3. The method of claim 1, wherein the epoxy resin water-based emulsion is prepared by a phase inversion method, and the method is characterized by, In the step (3), the stirring temperature is 60-70℃, the stirring speed is 1500-2000 rpm, and the stirring time is 15-20 min.

4. The method of claim 1, wherein the epoxy resin water-based emulsion is prepared by a phase inversion method, and the method is characterized by, In the step (4), the amount of water is 186-237 g, the titration speed is 5-15 g / min, the phase inversion treatment temperature is 70-80℃, and the emulsification time is 1.5-2 h.

5. The method of claim 1, wherein the epoxy resin water-based emulsion is prepared by a phase inversion method, and the method is characterized by, In the step (1), the mass ratio of the epoxy resin A to the epoxy resin B is 23:2, the mass ratio of the emulsifier C to the emulsifier D is 3:2, and the total amount of the emulsifier C and the emulsifier D is 0.17 times the total mass of the epoxy resin A and the epoxy resin B.

6. The method of claim 1, wherein the epoxy resin water-based emulsion is prepared by a phase inversion method. In the step (2), the amount of the organic solvent is 0.1 times the total mass of the epoxy resin.

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