阅读说明：本技术 一种植物油酸改性环氧丙烯酸酯光固化树脂及其制备方法 (Vegetable oleic acid modified epoxy acrylate photocureable resin and preparation method thereof ) 是由 聂俊 王娅娴 方大为 马贵平 于 2020-07-14 设计创作，主要内容包括：本发明公开了一种植物油酸改性环氧丙烯酸酯光固化树脂及其制备方法。利用含有不饱和双键的植物油脂肪酸对缩水甘油醚型环氧树脂开环反应,制备环氧油树脂,同时在分子结构中形成羟基。利用生成的羟基与马来酸酐反应制备含羧基的半酯,再与甲基丙烯酸缩水甘油酯反应,制备获得具有光固化活性的植物油酸改性环氧丙烯酸酯树脂。含有长链油脂结构,对涂覆的基材以及加入的颜填料有良好的润湿性。常用的双酚A型环氧树脂与羧基开环后,其分子结构中的羟基数通常大于2,因此所制备的植物油酸改性环氧丙烯酸酯树脂的官能度可大于2。分子结构的不饱和脂肪酸可催化氧化固化交联,从而可形成双固化交联网络,进一步改善涂层性能。(The invention discloses vegetable oleic acid modified epoxy acrylate light-cured resin and a preparation method thereof. The method comprises the steps of utilizing vegetable oil fatty acid containing unsaturated double bonds to carry out ring-opening reaction on glycidyl ether type epoxy resin to prepare the epoxy oil resin, and simultaneously forming hydroxyl in a molecular structure. The generated hydroxyl reacts with maleic anhydride to prepare half ester containing carboxyl, and then the half ester reacts with glycidyl methacrylate to prepare the vegetable oleic acid modified epoxy acrylate resin with photocuring activity. Contains long-chain grease structure and has good wettability to coated base materials and added pigments and fillers. After the ring opening of the common bisphenol A epoxy resin and carboxyl, the number of hydroxyl groups in the molecular structure is usually more than 2, so that the functionality of the prepared vegetable oleic acid modified epoxy acrylate resin can be more than 2. Unsaturated fatty acid with molecular structure can catalyze, oxidize, solidify and crosslink, thereby forming a dual-curing crosslinking network and further improving the performance of the coating.)

1. The vegetable oleic acid modified epoxy acrylate light-cured resin is characterized by having the following chemical structural general formula:

wherein R1 is a fatty acid ester or acrylate structure;

r2 is-H or

2. The preparation method of the vegetable oleic acid modified epoxy acrylate photocureable resin is characterized by comprising the following steps:

1) weighing epoxy resin in a three-neck flask, adding vegetable oleic acid-based unsaturated fatty acid, adding 1-3 wt% of tetrabutylammonium bromide catalyst, stirring, introducing N₂Heating to 100-120 ℃, reacting at constant temperature for 2h, testing the acid value, cooling to 90-110 ℃ when the acid value is less than 10mgKOH/g, dropwise adding acrylic acid for dissolving 500ppm of p-hydroxyanisole, and reacting at constant temperature after dropwise adding until the acid value of the system is reduced to 10 mgKOH/g;

2) adding maleic anhydride into the reaction system in the step 1), reacting at 90-100 ℃, testing the acid value every 1h, adding glycidyl methacrylate into the reaction system when the acid value difference measured in two consecutive times is less than 5mgKOH/g, adding a polymerization inhibitor and a catalyst, reacting at 100-115 ℃ until the acid value of the system is less than 10mgKOH/g, stopping the reaction, and discharging when the temperature is cooled to 80 ℃.

3. The method for preparing the vegetable oil acid modified epoxy acrylate light-cured resin according to claim 2, wherein the epoxy resin in the step 1) is bisphenol A epoxy resin E51.

4. The method for preparing the vegetable oleic acid-modified epoxy acrylate photocurable resin according to claim 2, wherein the vegetable oleic acid-based unsaturated fatty acid in the step 1) is one or more of oleic acid, linoleic acid, linolenic acid and dehydrated ricinoleic acid.

5. The method for preparing the vegetable oleic acid-modified epoxy acrylate photocurable resin according to claim 2, wherein the molar ratio of the vegetable oleic acid-based unsaturated fatty acid to the acrylic acid in the step 1) is 1: 0.5-1, wherein the molar ratio of the total carboxyl of the epoxy resin to the added vegetable oleic acid-based unsaturated fatty acid and acrylic acid is 1: 1-1.05.

6. The method for preparing the vegetable oleic acid-modified epoxy acrylate photocurable resin according to claim 2, wherein maleic anhydride is added in step 2) in an amount of 30 to 50% of the total molar number of the vegetable oleic acid-based unsaturated fatty acid and acrylic acid added in step 1); glycidyl methacrylate was added equimolar to the measured acid number.

7. The method for preparing the vegetable oil acid modified epoxy acrylate photocuring resin as claimed in claim 2, wherein the polymerization inhibitor in the step 2) is p-hydroxyanisole, and the addition amount of the polymerization inhibitor is 0.1-0.5 wt% of glycidyl methacrylate.

8. The method for preparing the vegetable oil acid modified epoxy acrylate photocuring resin according to claim 2, wherein the catalyst in the step 2) is one or a mixture of tetrabutylammonium bromide, tetramethylammonium chloride or triphenylphosphine, and the addition amount of the catalyst is 1-3 wt% of the total mass of the reaction system.

Technical Field

The invention belongs to the field of preparation of resin for a light-cured coating, and particularly relates to vegetable oleic acid modified epoxy acrylate light-cured resin and a preparation method thereof.

Technical Field

The photo-curing coating is a coating which utilizes ultraviolet light to decompose a photoinitiator to generate active species and initiate monomer polymerization so as to cure a coating. The adopted resin has low molecular weight, and small molecular monomers are used as reactive diluents, so that the coating system has low content of organic volatile matters and is environment-friendly. With the increasing emphasis on environmental protection, the research on environmental-friendly coatings is increasing. The variety of resins for photo-curable coating materials is increasing, and the resins used in large amounts include epoxy acrylate resins, polyester acrylate resins, urethane acrylate resins, and the like. However, with the expansion of the application field of the photo-curing coating and the gradual increase of the requirements on the performance of the photo-curing coating, the demand for the photo-curing resin with high performance is increasingly urgent.

Epoxy resins are one of the resin types commonly used in coating resins. However, cured films of aromatic ring-containing epoxy resins are generally poor in flexibility and the coatings are easily brittle. The variety of modified epoxy resins aiming at the brittleness problem of the epoxy resin is more, for example, vegetable oil acid dimer acid is adopted to open the epoxy resin, and a flexible fatty chain is introduced into the structure of the epoxy resin. However, due to the chain extension reaction, the molecular weight of the epoxy resin is greatly increased, and the viscosity of the reaction system is improved, so that the dosage of the solvent is increased, and the environment friendliness is not facilitated. Chinese patent CN 104710598A discloses another method for modifying epoxy resin with vegetable oleic acid: vegetable oleic acid is adopted to react with epoxy resin, part of epoxy groups are reserved for crosslinking and curing of the epoxy resin, and meanwhile, part of epoxy groups are sacrificed to react with flexible oleic acid to obtain flexibility. The modified epoxy resin prepared by this reaction is similar to the epoxy oil resin.

The epoxy oil resin is modified by vegetable oleic acid, and the cured coating of the epoxy oil resin has the characteristics of high adhesiveness, good mechanical strength, high flexibility of alkyd resin and good performance adjustability of the epoxy resin. The epoxy oil resin is prepared by the ring-opening oxygen reaction of vegetable oil acid. The prepared resin is crosslinked by catalytic oxidation curing to form a crosslinked network. However, compared with the epoxy resin system cured by the traditional epoxy curing agent, the strength of the epoxy oil resin cured film is obviously reduced, the crosslinking density is small, and the application range is limited.

Disclosure of Invention

The invention aims to provide vegetable oleic acid modified epoxy acrylate light-cured resin and a preparation method thereof.

The technical scheme adopted by the invention for solving the technical problems is as follows:

the chemical structural general formula of the vegetable oleic acid modified epoxy acrylate light-cured resin is as follows:

wherein R1 is a fatty acid ester or acrylate structure;

r2 is-H or

The preparation method of the vegetable oleic acid modified epoxy acrylate photocureable resin comprises the following steps:

1) weighing epoxy resin in a three-neck flask, adding vegetable oleic acid-based unsaturated fatty acid, adding 1-3 wt% of tetrabutylammonium bromide catalyst, stirring, introducing N₂Heating to 100-120 ℃, reacting at constant temperature for 2h, testing the acid value, cooling to 90-110 ℃ when the acid value is less than 10mgKOH/g, dropwise adding acrylic acid for dissolving 500ppm of p-hydroxyanisole, and reacting at constant temperature after dropwise adding until the acid value of the system is reduced to 10 mgKOH/g;

2) adding maleic anhydride into the reaction system in the step 1), reacting at 90-100 ℃, testing the acid value every 1h, adding glycidyl methacrylate into the reaction system when the acid value difference measured in two consecutive times is less than 5mgKOH/g, adding a polymerization inhibitor and a catalyst, reacting at 100-115 ℃ until the acid value of the system is less than 10mgKOH/g, stopping the reaction, and discharging when the temperature is cooled to 80 ℃.

Preferably, the epoxy resin in the step 1) is bisphenol a epoxy resin E51.

Specifically, the vegetable oil acid radical unsaturated fatty acid in the step 1) is one or more of oleic acid, linoleic acid and dehydrated ricinoleic acid.

Preferably, the molar ratio of the vegetable oil acid-based unsaturated fatty acid to the acrylic acid in the step 1) is 1: 0.5-1, wherein the molar ratio of the total carboxyl of the epoxy resin to the added vegetable oleic acid-based unsaturated fatty acid and acrylic acid is 1: 1-1.05.

Preferably, in the step 2), maleic anhydride is added according to 30-50% of the total mole number of the vegetable oleic acid-based unsaturated fatty acid and the acrylic acid added in the step 1); glycidyl Methacrylate (GMA) was added equimolar to the measured acid number.

Preferably, the polymerization inhibitor in the step 2) is p-hydroxyanisole, and the addition amount of the polymerization inhibitor is 0.1-0.5 wt% of glycidyl methacrylate; the catalyst is one or a mixture of more of tetrabutylammonium bromide, tetramethylammonium chloride or triphenylphosphine, and the addition amount of the catalyst is 1-3 wt% of the total mass of the reaction system.

Taking oleic acid as an example, the reaction process according to the charging ratio of oleic acid to acrylic acid of 1:1 is as follows:

the grafting position and the grafting rate of the maleic anhydride are not fixed, and the grafting degree can be adjusted through the reaction batch ratio, so that the grafting rate of the GMA is adjusted.

The invention has the following beneficial effects: the invention utilizes the hydroxyl of the epoxy oil resin structure to graft methacrylate double bonds on the side chain of the molecular structure, thus preparing the vegetable oleic acid modified epoxy acrylate resin. Vegetable oil fatty acid is introduced into the molecular structure, so that the brittleness problem of the epoxy acrylate is improved. Contains long-chain grease structure and has good wettability to coated base materials and added pigments and fillers. After the ring opening of the common bisphenol A epoxy resin and carboxyl, the number of hydroxyl groups in the molecular structure is usually more than 2, so that the functionality of the prepared vegetable oleic acid modified epoxy acrylate resin can be more than 2. The molecular structure contains an unsaturated fatty acid structure, can be cured by adopting a catalytic oxidation drying method, and can obtain a dual-curing cross-linked network by combining photocuring, so that the performance is more excellent; the grafted vegetable oil long carbon chain structure plays a plasticizing role and can obviously reduce the viscosity of the epoxy acrylate resin.

Drawings

FIG. 1 is an IR spectrum of a vegetable oil-modified epoxy acrylate resin prepared according to example 1.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.