阅读说明：本技术 以氧基二琥珀酸为基础制备的环氧粉末涂料用消光固化剂 (Extinction curing agent for epoxy powder coating prepared on basis of oxydisuccinic acid ) 是由 张文娟 于 2020-06-23 设计创作，主要内容包括：本发明公开了一种以氧基二琥珀酸为基础制备的环氧粉末涂料用消光固化剂,涉及多元羧酸与咪唑啉胺基化合物成盐制备消光固化剂及其环氧粉末涂料中的应用技术领域,该消光固化剂以2,2’-氧基二琥珀酸与2位碳上含有取代基的咪唑啉为原料,在极性溶剂中依次经过回流反应、过滤和干燥制备出,其中咪唑啉2位碳上取代基为芳基或者C1-C10的支链或直链烷基或取代芳基；本发明提供的消光固化剂既能够用于1,2-环氧化物又能够用于固体环氧树脂的混合物固化产生消光作用,消光效果良好,机械性能稳定；耐高温,易制备白色或浅色涂料；当本发明提供的消光固化剂应用于混合型消光系统中,光泽对聚酯的敏感性较小,消光效果稳定。(The invention discloses a delustering curing agent for epoxy powder coating prepared on the basis of oxydisuccinic acid, which relates to the technical field of application of the delustering curing agent prepared by salifying polycarboxylic acid and imidazoline amino compounds and the epoxy powder coating thereof, wherein the delustering curing agent is prepared by taking 2, 2' -oxydisuccinic acid and imidazoline containing a substituent on 2-site carbon as raw materials and sequentially performing reflux reaction, filtration and drying in a polar solvent, wherein the substituent on the 2-site carbon of the imidazoline is aryl or C1-C10 branched chain or straight chain alkyl or substituted aryl; the extinction curing agent provided by the invention can be used for curing a mixture of 1, 2-epoxide and solid epoxy resin to generate an extinction effect, and has good extinction effect and stable mechanical property; high temperature resistance, and easy preparation of white or light-colored paint; when the extinction curing agent provided by the invention is applied to a mixed extinction system, the sensitivity of gloss to polyester is small, and the extinction effect is stable.)

1. The extinction curing agent for the epoxy powder coating is prepared on the basis of oxydisuccinic acid, and is characterized in that the curing agent is salt generated by the reaction of 2, 2' -oxydisuccinic acid and imidazoline containing a substituent on the 2-site carbon, wherein the substituent on the 2-site carbon of the imidazoline is aryl or one of branched chain or straight chain alkyl or substituted aryl of C1-C10.

2. The matted curing agent for epoxy powder coatings prepared on the basis of oxydisuccinic acid according to claim 1, wherein said imidazoline is 2-phenylimidazoline.

3. The matted curing agent for epoxy powder coatings prepared based on oxydisuccinic acid of claim 1 wherein said imidazoline is 2-methylimidazoline.

4. The matted curing agent for epoxy powder coatings prepared on the basis of oxydisuccinic acid according to claim 1, wherein said imidazoline is 2-ethyl imidazoline.

5. The matting curing agent for oxydisuccinic acid based epoxy powder coating material as claimed in claim 1, wherein the matting curing agent is prepared by the following steps:

(1) heating and refluxing 2, 2' -oxydisuccinic acid and imidazoline amine in a polar solvent, and cooling a reaction liquid system after the reaction is finished;

(2) and (2) filtering the reaction liquid system in the step (1), and drying the obtained solid to obtain the target product.

6. The matting curing agent for oxydisuccinic acid based epoxy powder coating material as claimed in claim 1, wherein the molar ratio of 2, 2' -oxydisuccinic acid to imidazoline in step (1) is 1: 1-4.

7. The matted curing agent for epoxy powder paint prepared based on oxydisuccinic acid according to claim 1, wherein the polar solvent in step (1) is one of methanol, ethanol, DMF or water.

Technical Field

The invention relates to the technical field of preparation of a flatting curing agent by salifying polycarboxylic acid and an imidazoline amino compound and application of the flatting curing agent in epoxy powder coating, in particular to a flatting curing agent for epoxy powder coating prepared on the basis of oxydisuccinic acid.

Background

It is known that epoxy resins can be cured with various curing agents such as dicyandiamide, polybasic acids, hydrazides, boron trifluoride compounds, substituted dicyandiamide, etc., but in the case of special requirements such as low gloss, matte, etc., it is necessary to use a special curing agent or other methods to obtain the epoxy resin. The industry generally prepares the curing agent by four methods:

(1) adding inorganic filler or polymer powder such as calcium carbonate, pulvis Talci or polytetrafluoroethylene powder;

(2) dry mixing the powder with different reactivity;

(3) modifying the resin;

(4) is realized by adopting a special curing agent containing special amino and carboxyl functional groups.

Of the above four methods, the method (1) affects the spray property and the mechanical properties are difficult to be secured. The gloss reproducibility of the coating in the method (2) is not good, and it is difficult to ensure a uniform and stable gloss of the coating film. Modification of the resin in the process (3) may increase the cost or affect the flow properties of the resin. Method (4) is a commonly used, effective method for reducing gloss. The German patent Offenlegungss Chrift 2324696 describes a process for making a curing agent from a polyacid and an organic amine. It is a mono-or poly-salt formed from pyromellitic acid or trimellitic acid and cyclic amidines. The resin cured by the curing agent has the characteristics of good fluidity, stable gloss and the like, so that the curing agent is widely applied. However, the disadvantages of such curing agents are also evident, such as easy yellowing during baking and poor mechanical properties, so that the preparation of white or light-colored powder coatings with such curing agents is limited. Furthermore, the curing agent is sensitive to the dependence of gloss on polyester in the mixed system. Therefore, the invention provides a extinction curing agent for epoxy powder coating prepared on the basis of oxydisuccinic acid.

Disclosure of Invention

The invention aims to provide a delustering curing agent for epoxy powder coating prepared on the basis of oxydisuccinic acid, which solves the problems in the background technology.

In order to achieve the above object, the present invention provides a matting curing agent for epoxy powder coating prepared based on oxydisuccinic acid, which is a salt produced by the reaction of 2, 2' -oxydisuccinic acid (shown in formula 1) and imidazoline (shown in formula 2) containing substituent on 2-position carbon,

formula 1

Formula 2Wherein, R in the formula 2 is aryl or one of C1-C10 branched chain or straight chain alkyl or substituted aryl.

Preferably, the imidazoline having a substituent at the 2-carbon is 2-phenylimidazoline.

Preferably, the imidazoline is 2-methylimidazoline.

Preferably, the imidazoline is 2-ethylimidazoline.

Preferably, the preparation method of the extinction curing agent comprises the following steps:

(1) heating and refluxing polycarboxylic acid and imidazoline amine in a polar solvent, and cooling a reaction liquid system to normal temperature after the reaction is finished; wherein the refluxing time is determined by the solvent, the heating refluxing time is 2-4 hours, and the refluxing time at room temperature is different from dozens of hours to dozens of hours;

(2) and (2) filtering the reaction liquid system in the step (1), drying the obtained solid to obtain a target product, and recycling the mother liquid obtained by filtering.

Preferably, the molar ratio of the polycarboxylic acid to the imidazoline in the step (1) is 1: 1-4.

Preferably, the polar solvent in the step (1) is one of methanol, ethanol, DMF or water.

The above-described matting curing agents can be used both for 1, 2-epoxides and for mixtures of solid epoxy resins. The 1, 2-epoxide is an aliphatic, alicyclic, aromatic or heterocyclic compound which is solid at room temperature, and the 1, 2-epoxide may further contain a substituent which does not undergo a side reaction under the conditions of the present invention, such as a hydroxyl group, an aryl group, an ether group, a bromo group, and the like. The solid epoxy resin molecule must contain more than one epoxy group, the epoxy equivalent is 700-1400 ℃, the softening point is 85-110 ℃, and when the extinction curing agent is applied to the solid epoxy resin, the dosage of the extinction curing agent is 9-12% of the mass of the epoxy resin.

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

(1) the extinction effect is good, and the mechanical property is stable;

(2) good high temperature resistance, easy preparation of white or light-colored paint;

(3) in the mixed type extinction system, the glossiness is less sensitive to the polyester, and the extinction effect is stable.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.