阅读说明：本技术 一种支化改性的多官能度环氧丙烯酸酯光固化树脂及其制备方法 (Branched modified multifunctional epoxy acrylate light-cured resin and preparation method thereof ) 是由 汤峰 陈广凯 欧阳晓勇 于 2020-08-18 设计创作，主要内容包括：本发明属于树脂低聚物的合成领域,涉及一种支化改性的多官能度环氧丙烯酸酯光固化树脂及其制备方法；具体操作是利用环氧树脂及环氧丙烯酸酯分子结构中的羟基与酸酐反应制备含羧基的半酯,再与小分子量的环氧树脂、丙烯酸开环氧反应而在环氧丙烯酸酯树脂的侧链上接枝不同取代度的含丙烯酸双键的侧链,通过调节接枝度可调节树脂的官能度,从而调节树脂固化后材料的性能；本发明引入酸酐改性环氧丙烯酸酯树脂,通过调节羧酸与环氧树脂反应的投料比和投料次序,实现了环氧丙烯酸酯树脂的高度支化,所制备的树脂固化速率极快,交联密度高,具有良好的机械性能；解决了目前其固化膜脆性较大、耐候性较差的问题。(The invention belongs to the field of synthesis of resin oligomers, and relates to a branched modified multifunctional epoxy acrylate light-cured resin and a preparation method thereof; the specific operation is that hydroxyl in the molecular structures of epoxy resin and epoxy acrylate reacts with acid anhydride to prepare half ester containing carboxyl, then the half ester reacts with epoxy resin with small molecular weight and acrylic acid ring-opening oxygen to graft acrylic acid double bond-containing side chains with different degrees of substitution on the side chains of the epoxy acrylate resin, and the functionality of the resin can be adjusted by adjusting the degree of grafting, so that the performance of the cured material of the resin can be adjusted; according to the invention, the anhydride modified epoxy acrylate resin is introduced, and the high branching of the epoxy acrylate resin is realized by adjusting the feeding ratio and the feeding sequence of the reaction of carboxylic acid and the epoxy resin, so that the prepared resin has the advantages of extremely high curing rate, high crosslinking density and good mechanical property; solves the problems of larger brittleness and poorer weather resistance of the current curing film.)

1. A branched modified multifunctional epoxy acrylate light-cured resin is characterized in that the chemical structural formula is as follows:

r is

wherein x and (x + y) are (0.2-0.5) and 1.

2. The method for preparing the branched and modified multifunctional epoxy acrylate light-cured resin according to claim 1, comprising the following steps:

(1) heating the epoxy resin A to 90-110 ℃, adding a catalyst, then dropwise adding acrylic acid dissolving 500ppm of p-hydroxyanisole polymerization inhibitor, monitoring the acid value of a reaction system, adding anhydride into the reaction system when the acid value is less than 10mgKOH/g, continuing the reaction, measuring the acid value at certain intervals, and preparing the carboxyl-containing epoxy acrylate resin B when the acid value difference measured twice is less than 10 mgKOH/g;

(2) adding epoxy resin C and acrylic acid into the carboxyl-containing epoxy acrylate resin B prepared in the step (1), and reacting at the temperature of 90-110 ℃; and when the reaction is carried out until the acid value of the system is less than 5mgKOH/g, stopping the reaction, and preparing the obtained product, namely the branched modified multifunctional epoxy acrylate light-cured resin.

3. The method for preparing the branched and modified multifunctional epoxy acrylate photocuring resin as claimed in claim 2, wherein in the step (1), the mass ratio of the epoxy resin A, the propylene dissolved with 500ppm of p-hydroxyanisole polymerization inhibitor, the catalyst and the anhydride is 100: 14.4-36.7: 0.5-1: 12.3-37.

4. The method for preparing the branched and modified multifunctional epoxy acrylate light-cured resin according to claim 2 or 3, wherein the epoxy resin A is one or more of epoxy resins E51, E44, E30 or E20.

5. The method for preparing the branched modified multifunctional epoxy acrylate light-cured resin according to claim 2 or 3, wherein the acid anhydride is one or more of maleic anhydride, phthalic anhydride or succinic anhydride.

6. The method for preparing the branched modified multifunctional epoxy acrylate light-cured resin according to claim 2 or 3, wherein the catalyst is one or a mixture of tetrabutylammonium bromide, tetramethylammonium chloride or triphenylphosphine; the adding amount of the catalyst is 0.5-1.0 wt% of the total mass of the system.

7. The method for preparing a branched modified multifunctional epoxy acrylate photocurable resin according to claim 2, wherein in step (1), the time interval is 1 h.

8. The method for preparing the branched modified multifunctional epoxy acrylate photocurable resin according to claim 2, wherein in the step (2), the epoxy resin C is epoxy resin E51.

9. The method for preparing the branched and modified multifunctional epoxy acrylate photocurable resin according to claim 2, wherein in the step (2), the mass ratio of the carboxyl group-containing epoxy acrylate resin B, the epoxy resin C and the acrylic acid is (100-150): (25-100): (10-36).

Technical Field

The invention belongs to the field of synthesis of resin oligomers, and particularly relates to a branched modified multifunctional epoxy acrylate light-cured resin and a preparation method thereof.

Background

The epoxy acrylate resin curing film has good adhesive force to various base materials due to the fact that a molecular structure contains a large number of hydroxyl groups and ether bond structures; the cured film has excellent chemical resistance, so that the epoxy resin is applied to the field of various protective coatings. For metal corrosion, it is commonly used as an anti-rust primer because it has good alkali resistance against alkali substances generated from a cathode during metal corrosion. Due to the excellent properties and wide application of epoxy resins, epoxy acrylate resins are an important member of photopolymerizable resins in the preparation of photopolymerizable resins.

Epoxy groupIs a ternary ring structure containing oxygen atoms, and is easy to generate ring-opening reaction due to higher ring tension; these reactions are commonly used for curing and modifying epoxy resins. The reaction of opening epoxy by carboxyl in the preparation process of the epoxy acrylate resin is most widely applied, and the carboxyl can be opened epoxy under the catalysis of quaternary ammonium salt or triphenyl phosphine, such as opening epoxy by acrylic acid; the carboxyl anion can also be produced under alkaline conditions, and the reaction can be carried out by a nucleophilic reaction mechanism. As the basic catalyst, 2-phenylimidazole, dimethylbenzylamine and the like are generally used. A large number of hydroxyl groups in the epoxy resin structure can also be used for modifying the epoxy resin; for example, an epoxy resin is subjected to a ring-opening reaction with an acid anhydride to prepare an alkali-soluble epoxy acrylate resin having a certain carboxyl group.

Epoxy resins, while having excellent properties, still have deficiencies. Bisphenol A type epoxy resin contains a large number of benzene rings in a molecular structure, and a cured film of the bisphenol A type epoxy resin is high in brittleness and poor in weather resistance; in addition, the molecular structure contains a large number of hydroxyl groups, resulting in a high viscosity of the epoxy resin. According to the invention, acrylic acid and anhydride are adopted, a simple carboxyl ring-opening oxygen reaction is utilized, and the epoxy acrylate resin with high branching and polyfunctionality is designed and prepared through different feeding sequences and feeding ratios; the resin has the advantages of extremely high curing speed, high crosslinking density and good mechanical properties.

Disclosure of Invention

Aiming at overcoming the defects in the prior art, the invention aims to provide a branched modified multifunctional epoxy acrylate light-cured resin and a preparation method thereof. The invention aims to design and prepare the epoxy acrylate resin with different branching degrees so as to obtain the epoxy acrylate resin with adjustable crosslinking density, and the related raw materials are easy to obtain in the market, have reasonable cost and are suitable for large-scale mass production.

The present invention achieves the above-described object by the following technical means.

The invention firstly provides a branched modified multifunctional epoxy acrylate light-cured resin, which has the following chemical structural formula:

r isAny one of the above;

wherein x and (x + y) are (0.2-0.5) and 1.

R is a group corresponding to the added anhydride and is selected according to the type of the added anhydride.

The invention also provides a preparation method of the branched modified multifunctional epoxy acrylate light-cured resin, which comprises the following specific steps:

(1) heating the epoxy resin A to 90-110 ℃, adding a catalyst, then dropwise adding acrylic acid dissolving 500ppm of p-hydroxyanisole polymerization inhibitor, monitoring the acid value of a reaction system, adding anhydride into the reaction system when the acid value is less than 10mgKOH/g, continuing the reaction, measuring the acid value at certain intervals, and preparing the carboxyl-containing epoxy acrylate resin B when the acid value difference measured twice is less than 10 mgKOH/g;

(2) adding epoxy resin C and acrylic acid into the carboxyl-containing epoxy acrylate resin B prepared in the step (1), and reacting at the temperature of 90-110 ℃; and when the reaction is carried out until the acid value of the system is less than 5mgKOH/g, stopping the reaction, and preparing the obtained product, namely the branched modified multifunctional epoxy acrylate light-cured resin.

Further, in the step (1), the epoxy resin A is one or more of epoxy resin E51, E44, E30 or E20.

Further, in the step (1), the catalyst is one or a mixture of tetrabutylammonium bromide, tetramethylammonium chloride and triphenylphosphine; the adding amount of the catalyst is 0.5-1.0 wt% of the total mass of the system.

Further, in the step (1), the acid anhydride is one or more of maleic anhydride, phthalic anhydride or succinic anhydride.

Further, in the step (1), the mass ratio of the epoxy resin A, propylene dissolved with 500ppm of p-hydroxyanisole polymerization inhibitor, catalyst and acid anhydride is 100 (14.4-36.7): (0.5-1): (12.3-37).

Further, in the step (1), the interval is 1 h.

Further, in the step (2), the epoxy resin C is epoxy resin E51.

Further, in the step (2), the mass ratio of the carboxyl-containing epoxy acrylate resin B, the epoxy resin C and the acrylic acid is (100-150) to (25-100): (10-36).

The invention has the advantages and technical effects that:

(1) the process is simple and controllable, and the modified raw material is an anhydride compound, so that the raw material is wide in source and low in cost.

(2) According to the invention, acrylic acid and anhydride are adopted, a simple carboxyl ring-opening oxygen reaction is utilized, and the epoxy acrylate resin with high branching and polyfunctionality is designed and prepared through different feeding sequences and feeding ratios, so that the prepared resin has the advantages of extremely high curing rate, high crosslinking density and good mechanical property; solves the problems of larger brittleness and poorer weather resistance of the current curing film.

Drawings

FIG. 1 is an IR spectrum of a resin prepared in example 1 of the present invention.

Detailed Description

The invention is further illustrated by the following examples.