Water-based polyaspartic acid ester resin and preparation method thereof

Abstract

The invention discloses a water-based polyaspartic acid ester resin and a preparation method thereof, and relates to the technical field of resin synthesis. The water-based polyaspartic acid ester resin is mainly prepared from the following resin raw materials: a polybasic primary amine compound, maleate and alkyl etherified monohydroxy polyether according to wherein molar ratio of (0.8-1.2):(1.6-3.6):(0.2-6.0), and has the advantages of good hydrophilicity, light color, convenience in construction and excellent weather resistance and yellowing resistance. The preparation method of the water-based polyaspartic acid ester resin comprises the following steps: addition, ester exchange, purification and the like, and has the advantages that oil-soluble resin can be converted into water-solubleresin, and VOC emission is reduced.

Description

technical field [0001] The invention relates to the technical field of resin synthesis, in particular to a water-based polyaspartic acid ester resin and a preparation method thereof. Background technique [0002] Polyaspartic acid ester resin is a high-solid low-viscosity resin containing secondary amino groups synthesized by the Michael addition reaction of polybasic primary amino compounds and maleic acid esters. The reaction formula is as follows: [0003] [0004] In the reaction formula, R is an alkyl group, and X is an aliphatic hydrocarbon group. Polyaspartic ester resin is combined with aliphatic isocyanate curing agent to prepare polyaspartic ester coatings with excellent mechanical properties and aging resistance. However, the polyaspartate resin prepared by this method is lipophilic and has poor water solubility, and its downstream coating products can only be organic solvent-based, which cannot be used in water-based coating systems, which limits its applicat...

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Problems solved by technology

This technical solution has the following defects: 1. When the selected catalyst performs transesterification or esterification reaction under high temperature conditions, the color of the product will be seriously deepened, and the residue of the catalyst will bring disadvantages to the construction performance of the downstream coating and the performance of the final product. 2. When the transesterification or esterification reaction is carried out under high temperature conditions, the double bonds in the maleic acid ester will be partially polymerized, which will produce polymer impurities, which will adversely affect the performance of downstream coatings; if additional The polymerization inhibitor will introduce new polymerization inhibitor impurities, which will also adversely affect the performance of downstream coatings; 3. If the maleic acid ester after transesterification or esterification is rectified to remove impurities, when used High-molecular-weight polyethylene / propylene glycol monoether is transesterified or esterified to produce maleic acid esters, and its product distillation will be accompanied by product decomposition, so only low-molecular-weight polyethylene / propylene glycol monoether raw materials can be used; Low molecular weight polyethylene / propylene glycol monoether raw materials, due to the low boiling point of low molecular weight polyethylene / propylene glycol monoether, are easy to run out, so the reaction temperature of transesterification or esterification should not be too high, and can only be used at lower temperatures transesterification or esterification reaction, which reduces the reaction rate of transesterification or esterification reaction, reduces the conversion rate of transesterification or esterification reaction

However, this technical solution has the following defects: 1. The steric hindrance of the secondary amino group obtained by the addition reaction of the primary amino compound and the unsaturated monocarboxylic acid is small, which causes the reactivity of the polyaspartic acid ester to be too high and the reaction is too high. Fast, short pot life, which is not conducive to the construction of subsequent coating products; 2. In the subsequent preparation of coatings, this technical solution needs to add an additional organic base to neutralize the carboxyl groups in the molecule, and the ammonia in the organic base will have peculiar smell, which will seriously Affect the constructability of the product; 3. The carboxyl group contained in the product of this technical solution will also affect the weather resistance and yellowing resistance of the product

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