阅读说明：本技术 一种低粘度水性环氧乳液的制备方法 (Preparation method of low-viscosity water-based epoxy emulsion ) 是由 蒋峰 孙祥 杨颖� 陈铭铸 俞孝伟 宋桂成 侯晶晶 于 2019-09-03 设计创作，主要内容包括：本发明公开了一种低粘度水性环氧乳液的制备方法,首先在N2保护下,聚氧化乙烯类化合物与环氧固化剂进行反应,得到水性环氧乳化剂,再用该乳化剂和固体环氧树脂、助溶剂混合并进行高速剪切,加入去离子水在剪切力的作用下制备得到水性环氧乳液。本发明采用外加乳化剂法制备水性环氧乳液,安全环保,且乳化剂分子中含有类环氧链段,与环氧树脂有着较好的相似相溶性,制备得到的水性环氧乳液粘度低且稳定性好,方便使用。(the invention discloses a preparation method of low-viscosity water-based epoxy emulsion, which comprises the steps of firstly, under the protection of N2, reacting a polyoxyethylene compound with an epoxy curing agent to obtain a water-based epoxy emulsifier, then mixing the emulsifier, solid epoxy resin and a cosolvent, carrying out high-speed shearing, and adding deionized water to prepare the water-based epoxy emulsion under the action of shearing force. The invention adopts an external emulsifier method to prepare the water-based epoxy emulsion, is safe and environment-friendly, has better similar intermiscibility with epoxy resin because the emulsifier molecule contains an epoxy-like chain segment, and has low viscosity, good stability and convenient use.)

1. a preparation method of a low-viscosity water-based epoxy emulsion is characterized by comprising the following steps:

1) in N₂under protection, heating and dehydrating the polyoxyethylene compound for 2 hours, and then adding the epoxy curing agent for full mixing;

2) in the mixed system in the step 1), carrying out heat preservation reaction for 2-4 h to obtain an emulsifier product;

3) mixing the emulsifier product obtained in the step 2) with solid epoxy resin and cosolvent, and stirring and heating until the system is uniform;

4) In the system of the step 3), deionized water is dripped within 2 hours at a certain temperature for shearing and emulsification, and after the dripping is finished, the water-based epoxy emulsion product is obtained by heat preservation and shearing and emulsification.

2. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the polyoxyethylene compounds in step 1) are polyethylene glycol, polypropylene glycol and polyethylene glycol glycidyl ether, polypropylene glycol glycidyl ether.

3. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the epoxy curing agent in step 1) is a fatty amine, a modified amine, or an acid anhydride.

4. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the molar ratio of the polyoxyethylene compound to the epoxy curing agent in the step 1) is 1:3 to 1: 1.

5. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the reaction temperature of the step 2) is 100 ℃ to 140 ℃.

6. the method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the solid epoxy resin in the step 3) is any one or a mixture of two or more of No. 1-4 solid epoxy resins; the cosolvent is one or a mixed solvent of two or more of alcohol solvents and ether solvents.

7. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the mass ratio of the emulsifier, the solid epoxy resin and the cosolvent in the step 3) is 1: 6-8: 2.

8. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the shear emulsification temperature in the step 4) is 40 ℃ to 80 ℃ and the heat-preserving shear emulsification time is 0.5h to 1 h.

9. the method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the linear shear rate in step 4) is 8-15 m/s.

10. The method for preparing a low viscosity aqueous epoxy emulsion according to claim 1, wherein the amount of deionized water added in the step 4) is 50-100% by mass of the solid epoxy resin.

Technical Field

The invention relates to a preparation method of a low-viscosity water-based epoxy emulsion, belonging to the field of new technology development of chemical products.

Background

the epoxy resin is one of three general thermosetting resins, has excellent technological properties, mechanical properties and physical properties, and is widely applied to the fields of mechano-electronics, aerospace, traffic, building and the like. Currently, 40% of epoxy resins are used in coatings worldwide, and most epoxy resins are insoluble in water, so most of the epoxy resin coatings commonly used at present are solvent-based. And the defects of flammability, explosiveness, toxicity, environmental pollution and the like of the organic solvent bring much inconvenience to storage, transportation and construction. With the progress of society, the continuous improvement of the requirements of people on the environmental quality and the continuous perfection of environmental protection standards and regulations of various countries, environment-friendly green chemicals and materials containing no or less Volatile Organic Compounds (VOC) and Harmful Air Pollutants (HAP) are widely concerned, and environment-friendly water-based epoxy resin is produced and is more and more emphasized by people and is rapidly developed.

the viscosity of the water-based epoxy emulsion products in the current market is generally higher, the stability is poor, and the development requirements of the industries such as water-based epoxy terrace, paint and the like are difficult to meet. The water-based epoxy emulsion prepared by the invention has low viscosity, good stability and extremely convenient use, and is suitable for large-scale popularization and application.

disclosure of Invention

The invention aims to overcome the defects of the existing product and provides a preparation method of a water-based epoxy emulsion with low viscosity and good stability.

in order to achieve the purpose, the invention provides the technical scheme that: a preparation method of low-viscosity water-based epoxy emulsion comprises the following steps,

1) Under the protection of N2, heating and dehydrating a polyoxyethylene compound for 2 hours, and then adding an epoxy curing agent for full mixing;

2) In the mixed system in the step 1), carrying out heat preservation reaction for 2-4 h to obtain an emulsifier product;

3) Mixing the emulsifier product obtained in the step 2) with solid epoxy resin and cosolvent, and stirring and heating until the system is uniform;

4) In the system of the step 3), deionized water is dripped within 2 hours at a certain temperature for shearing and emulsification, and after the dripping is finished, the water-based epoxy emulsion product is obtained by heat preservation and shearing and emulsification.

in step 1) of the above method, the polyoxyethylene-based compound is polyethylene glycol, polypropylene glycol, and polyethylene glycol glycidyl ether, polypropylene glycol glycidyl ether.

In step 1) of the above method, the epoxy curing agent is preferably a fatty amine, a modified amine, or an acid anhydride.

in step 1) of the above method, the molar ratio of the polyoxyethylene-based compound to the epoxy curing agent is preferably 1:3 to 1: 1.

In step 2) of the above method, the reaction temperature is preferably maintained at 100 ℃ to 140 ℃.

In the step 3) of the method, the solid epoxy resin is any one of No. 1-4 solid epoxy resins or a mixture of two or more of the solid epoxy resins; the cosolvent is one or a mixed solvent of two or more of alcohol solvents and ether solvents.

In the above method, preferably, the mass ratio of the emulsifier, the solid epoxy resin, and the cosolvent in step 3) is 1: 6-8: 2.

The shearing and emulsifying temperature in the step 4) of the method is 40-80 ℃, and the heat preservation shearing and emulsifying time is 0.5-1 h.

The linear shearing speed in the step 4) of the method is 8-15 m/s.

preferably, the amount of the deionized water added in the step 4) of the method is 50 to 100 percent of the mass of the solid epoxy resin.

compared with the prior art, the invention has the beneficial effects that: the water-based epoxy emulsion is prepared by an external emulsifier method, a polyoxyethylene chain segment and an epoxy curing agent are introduced into the emulsifier, the water-based epoxy emulsion has good similar compatibility with bisphenol A epoxy resin, and the prepared water-based epoxy emulsion has good stability and can meet the requirements of various applications.

Detailed Description

The following further describes the embodiments of the present invention. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.