Dicyclopentadiene modified waterborne epoxy ester resin and preparation method thereof

Abstract

The invention relates to epoxy resin. The dicyclopentadiene modified waterborne epoxy ester resin is prepared from the following components in parts by weight: 2 to 6 parts of unsaturated acid, 1 to 5 parts of acrylate monomer, 0.1 to 1 part of initiator, 40 to 65 parts of dicyclopentadiene modified epoxy ester intermediate, 10 to 30 parts of ethylene glycol monobutyl ether and 20 to 25 parts of styrene. The dicyclopentadiene modified water-based epoxy ester resin is applied to water-based epoxy ester paint, and the technical problems that the water-based epoxy ester paint is not high in hardness and poor in water resistance are solved. The invention also provides a preparation method of the dicyclopentadiene modified waterborne epoxy ester resin.

Description

Technical Field

[0001] The invention relates to an epoxy resin, in particular to a dicyclopentadiene modified waterborne epoxy ester resin and a preparation method thereof. Background Art

[0002] With the continuous progress of society and the rapid development of science and technology, in the automotive industry, fuel vehicles are gradually transitioning to electric vehicles. This change has promoted the growth of demand for related parts such as automobile chassis. As a key component of the automobile, the anti-corrosion protection of the automobile chassis is crucial and directly related to the safety and service life of the vehicle. At present, the industry mainly uses two-component water-based epoxy paint and water-based epoxy ester paint to solve the anti-corrosion protection of this component.

[0003] As an anti-corrosion coating, water-based epoxy ester paint is mainly made of fatty acids and epoxy resins as film-forming substances. It combines the respective advantages of drying vegetable oils and epoxy resins, and undergoes self-crosslinking reaction through air oxidation at room temperature, effectively improving the water resistance and weather resistance of the coating. However, due to the long-chain structural characteristics of a single fatty acid, even if the molecular weight increases during air oxidation and crosslinking, the resulting paint film is still relatively soft and the hardness increases slowly, making it difficult to meet the industry's demand for immediate packaging and stacking of automobile chassis after low-temperature baking. This limitation often requires customers to wait for several days before stacking workpieces, which seriously affects production efficiency. It is a long-standing pain point in the industry and has not been effectively resolved.

[0004] Although the industry has been exploring new methods to improve the hardness and water resistance of water-based epoxy ester paints, there are no reports on the use of dicyclopentadiene to modify water-based epoxy ester resins to improve their hardness and water resistance. As a compound with a rigid structure, dicyclopentadiene has unique air-oxidizing groups that can promote cross-linking reactions in the air under the action of a drying agent, which can effectively improve the hardness of the paint film in theory. However, how to effectively apply it to the modification of water-based epoxy ester resins to achieve a dual improvement in hardness and water resistance is still a technical problem that needs to be solved.

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a dicyclopentadiene-modified waterborne epoxy ester resin and a preparation method thereof.

[0006] The present invention aims to modify the water-based epoxy ester resin by introducing dicyclopentadiene and making full use of its rigid structure and air-oxidizing group characteristics, thereby effectively improving the drying speed, hardness and water resistance of the paint film, meeting the anti-corrosion protection needs of the automobile chassis, and solving the pain points of the prior art such as slow improvement of the paint film hardness and long waiting time for packaging and stacking. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a dicyclopentadiene-modified waterborne epoxy ester resin, which is applied to waterborne epoxy ester paint, and helps to solve the technical problems of low hardness and poor water resistance of waterborne epoxy ester paint. The present invention also provides a preparation method of the dicyclopentadiene-modified waterborne epoxy ester resin.

[0008] The technical solution adopted by the present invention to solve the above problems is as follows:

[0009] A dicyclopentadiene modified waterborne epoxy ester resin is prepared by raw materials comprising the following components by weight: 2-6 parts of unsaturated acid, 1-5 parts of acrylate monomers, 0.1-1 parts of initiator, 40-65 parts of dicyclopentadiene modified epoxy resin intermediate, 10-30 parts of ethylene glycol monobutyl ether and 20-25 parts of styrene.

[0010] Furthermore, the unsaturated acid is at least one of acrylic acid, methacrylic acid and maleic acid.

[0011] Furthermore, the acrylic acid ester monomer is at least one of butyl acrylate, methyl methacrylate and isooctyl acrylate.

[0012] Furthermore, the initiator is at least one of benzoyl peroxide, tert-butyl perbenzoate, diisopropylbenzene peroxide, and di-tert-butyl peroxide.

[0013] Furthermore, the raw materials for preparing the dicyclopentadiene-modified epoxy resin intermediate include the following components in parts by weight: 15 to 25 parts of vegetable fatty acids, 30 to 45 parts of epoxy resins, 15 to 25 parts of dicyclopentadiene adducts, 0.1 to 0.3 parts of xylene, and 15 to 20 parts of ethylene glycol monobutyl ether.

[0014] Furthermore, the preparation method of the dicyclopentadiene modified epoxy lipid intermediate comprises the following steps:

[0015] A. Add dicyclopentadiene adduct, vegetable fatty acid, epoxy resin and xylene into a reactor according to the formula, mix, heat to 150-170°C to start condensation reflux, continue to heat to 210-220°C, and carry out heat preservation reaction;

[0016] B. When the acid value is less than or equal to 10 (mgKOH / g), remove xylene by vacuum distillation, then cool to 120-170°C, add ethylene glycol monobutyl ether, stir, filter, and obtain a dicyclopentadiene-modified epoxy resin intermediate.

[0017] Furthermore, the vegetable oil fatty acid is at least one of soybean oleic acid, linoleic acid, dehydrated ricinoleic acid and eleostearic acid.

[0018] Furthermore, the epoxy resin is at least one of E-51, E-44, E-20, and E-128.

[0019] Furthermore, the epoxy value of the epoxy resin is 0.09 to 0.15 mol / 100g.

[0020] Furthermore, the raw materials for preparing the dicyclopentadiene adduct include the following components in parts by weight: 55-65 parts of dicyclopentadiene, 30-35 parts of maleic anhydride, 5.5-7 parts of deionized water, and 0.008-0.01 parts of p-methoxyphenol.

[0021] Furthermore, the preparation method of the dicyclopentadiene adduct comprises: adding dicyclopentadiene, maleic anhydride and p-methoxyphenol into a reactor according to the formula amount, heating to 100-120° C., starting to drop deionized water, and keeping warm after the dropwise addition is completed until the acid value is less than or equal to 135 (mgKOH / g), thereby obtaining the dicyclopentadiene adduct.

[0022] The present invention also provides a method for preparing a dicyclopentadiene-modified waterborne epoxy ester resin, comprising the following steps:

[0023] S1. The unsaturated acid, the acrylate monomer, the initiator and the styrene are mixed to obtain a mixture;

[0024] S2. The dicyclopentadiene modified epoxy resin intermediate is added to the reactor, heated to 130 to 150 ° C, and the mixture obtained in step S1 is added dropwise while stirring, and the mixture is kept warm after the addition is completed;

[0025] S3. After the heat preservation is completed, the temperature is lowered, ethylene glycol monobutyl ether is added to adjust the solid content, and the mixture is filtered to obtain a dicyclopentadiene-modified water-based epoxy ester resin.

[0026] Furthermore, the insulation time is 1 to 4 hours.

[0027] The present invention has the following beneficial effects:

[0028] The present invention introduces dicyclopentadiene into the epoxy molecular chain to replace part of the drying oleic acid. Since dicyclopentadiene has a special rigid structure and air-oxidizable functional groups, the glass transition temperature of the epoxy ester resin synthesized by the dicyclopentadiene is higher than that of the epoxy ester resin synthesized entirely with the drying oleic acid. Under air oxidation, the double bonds in the molecular structure are oxidized and cross-linked, so that the molecular weight of the paint film surface becomes larger and the hardness is rapidly improved. In addition, in the process of preparing the water-based epoxy ester, the present invention adds acrylic acid and its ester monomers and grafts them onto the polymer molecular chain so that the polymer has a hydration effect, and the performance of the water-based epoxy ester resin is synergistically improved with dicyclopentadiene. The water-based epoxy ester resin is further applied to the preparation of water-based epoxy ester paint, which helps to solve the technical problems of low hardness and poor water resistance of the water-based epoxy ester paint, and can obtain a water-based epoxy ester paint with a paint film hardness, drying speed and water resistance that are one level higher than those of ordinary water-based epoxy ester paint. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are not limitations of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Unless otherwise specified, the test materials, reagents, methods and equipment used in the following examples are conventional test materials, reagents, methods and equipment in the technical field; unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources. The quantitative tests in the following examples were all repeated three times, and the data are the average or average ± standard deviation of the three repeated experiments.

[0031] In some specific embodiments of the present invention, the raw materials for preparing the dicyclopentadiene adduct include the following components in parts by weight: 55-65 parts of dicyclopentadiene, 30-35 parts of maleic anhydride, 5.5-7 parts of deionized water, and 0.008-0.01 parts of p-methoxyphenol.

[0032] In some specific embodiments of the present invention, the preparation method of the dicyclopentadiene adduct comprises: adding dicyclopentadiene, maleic anhydride, and p-methoxyphenol into a reactor according to the formula amount, mixing, heating to 100-120° C., starting to drop deionized water, and keeping warm after the dropwise addition is completed until the acid value is less than or equal to 135 (mgKOH / g), thereby obtaining the dicyclopentadiene adduct.

[0033] In a specific embodiment, when preparing the dicyclopentadiene adduct, the specific amount of each component is shown in the following Table 1 (unit: weight part).

[0034] Table 1: Dicyclopentadiene adduct formulation

[0035] Components Dicyclopentadiene adduct a Dicyclopentadiene adduct b Dicyclopentadiene 60 100 Dicyclopentadiene solid content (%) 95 95 Maleic anhydride 33.2 33.2 Deionized water 6.8 6.8 p-Methoxyphenol 0.01 0.01

[0036] In some specific embodiments of the present invention, the raw materials for preparing the dicyclopentadiene-modified epoxy resin intermediate include the following components in parts by weight: 15 to 25 parts of vegetable fatty acids, 30 to 45 parts of epoxy resins, 15 to 25 parts of dicyclopentadiene adducts, 0.1 to 0.3 parts of xylene, and 15 to 20 parts of ethylene glycol monobutyl ether.

[0037] In some specific embodiments of the present invention, the vegetable oil fatty acid is at least one of soybean oleic acid, linoleic acid, dehydrated ricinoleic acid, and eleostearic acid.

[0038] In some specific embodiments of the present invention, the epoxy resin is at least one of E-51, E-44, E-20, and E-128.

[0039] In some specific embodiments of the present invention, the epoxy value of the epoxy resin is 0.09 to 0.15 mol / 100g.

[0040] In some specific embodiments of the present invention, the method for preparing the dicyclopentadiene modified epoxy lipid intermediate comprises the following steps:

[0041] A. Add dicyclopentadiene adduct, vegetable fatty acid, epoxy resin and xylene into the reactor according to the formula, heat to 150-170°C to start condensation reflux, continue to heat to 210-220°C, and carry out heat preservation reaction;

[0042] B. When the acid value is less than or equal to 10 (mgKOH / g), remove xylene by vacuum distillation, then cool to 120-170°C, add ethylene glycol monobutyl ether, stir, filter, and obtain a dicyclopentadiene-modified epoxy resin intermediate.

[0043] In a specific embodiment, when preparing the dicyclopentadiene-modified epoxy resin intermediate, the specific amount of each component is shown in Table 2 below (unit: parts by weight).

[0044] Table 2: Dicyclopentadiene modified epoxy resin intermediate formula

[0045]

[0046]

[0047] A dicyclopentadiene modified waterborne epoxy ester resin is prepared by raw materials comprising the following components by weight: 2-6 parts of unsaturated acid, 1-5 parts of acrylate monomers, 0.1-1 parts of initiator, 40-65 parts of dicyclopentadiene modified epoxy resin intermediate, 10-30 parts of ethylene glycol monobutyl ether and 20-25 parts of styrene.

[0048] In some specific embodiments of the present invention, the unsaturated acid is at least one of acrylic acid, methacrylic acid, and maleic acid.

[0049] In some specific embodiments of the present invention, the acrylic acid ester monomer is at least one of butyl acrylate, methyl methacrylate, and isooctyl acrylate.

[0050] In some specific embodiments of the present invention, the initiator is at least one of benzoyl peroxide, tert-butyl perbenzoate, diisopropylbenzene peroxide, and di-tert-butyl peroxide.

[0051] In some specific embodiments of the present invention, a method for preparing a dicyclopentadiene-modified waterborne epoxy ester resin comprises the following steps:

[0052] S1. The unsaturated acid, the acrylate monomer, the initiator and the styrene are mixed to obtain a mixture;

[0053] S2. The dicyclopentadiene modified epoxy resin intermediate is added to the reactor, heated to 130 to 150 ° C, and the mixture obtained in step S1 is added dropwise while stirring, and the mixture is kept warm after the addition is completed;

[0054] S3. After the heat preservation is completed, the temperature is lowered, ethylene glycol monobutyl ether is added to adjust the solid content, and the mixture is filtered to obtain a dicyclopentadiene-modified water-based epoxy ester resin.

[0055] In some specific embodiments of the present invention, the insulation time is 1 to 4 hours.

[0056] In a specific embodiment, the method for preparing the dicyclopentadiene-modified waterborne epoxy ester resin in embodiments 1 to 5 comprises the following steps:

[0057] S1. 3.5 parts of acrylic acid, 1 part of butyl acrylate and 3.5 parts of methyl methacrylate, 1.5 parts of benzoyl peroxide and 25 parts of styrene were mixed to obtain a mixture;

[0058] S2. Add 45 parts of dicyclopentadiene modified epoxy resin intermediate into the reactor, heat to 130-150°C, add dropwise the mixture obtained in step S1 while stirring, and keep warm for 1-4h after the addition is completed;

[0059] S3. After the heat preservation is completed, the temperature is lowered, 20.5 parts of ethylene glycol monobutyl ether are added to adjust the solid content, and the mixture is filtered to obtain a dicyclopentadiene-modified water-based epoxy ester resin.

[0060] The method for preparing waterborne epoxy resin in Comparative Example 1 can be obtained in the same manner.

[0061] Table 3: Dicyclopentadiene modified waterborne epoxy ester resin formulations of Examples 1 to 5

[0062] raw material Dosage Dicyclopentadiene modified epoxy resin intermediate 45 acrylic acid 3.5 Butyl acrylate 1 Methyl Methacrylate 3.5 Benzoyl peroxide 1.5 Styrene 25 Ethylene glycol monobutyl ether 20.5 total 100

[0063] The dicyclopentadiene modified waterborne epoxy ester resins prepared in Examples 1 to 5 and the waterborne epoxy resin prepared in Comparative Example 1 were respectively formulated into waterborne industrial anticorrosive coatings for performance comparison tests. The specific formula of the waterborne industrial anticorrosive coating is shown in Table 4 below (unit: kg).

[0064] Table 4: Water-based industrial anti-corrosion coating formulation

[0065]

[0066]

[0067] Among them, the performance test method is as follows:

[0068] (1) Adhesion: According to GB / T1720-1988, the cross-cut method is used for testing;

[0069] (2) Hardness: The hardness of the paint film is measured according to the paint and clear pencil method of GB / T6739-2006;

[0070] (3) Water resistance: Tested in accordance with the provisions of GB / T1733-93;

[0071] (4) Resistance to artificial aging: Test in accordance with the provisions of GB / T16422.4-2014 Sunlight-resistant carbon arc lamp aging test standard.

[0072] The above performances were tested in accordance with relevant international standards, and the test methods were all commonly used evaluation methods by those skilled in the art. The performance test results are shown in Table 5.

[0073] Table 5: Performance test results of embodiments and comparative examples

[0074]

[0075]

[0076] As can be seen from Table 5, after the rigid structure of dicyclopentadiene is introduced into the epoxy molecular chain, the hardness of the paint film is increased to more than the H level, because dicyclopentadiene has an air oxidation group, and in the presence of a drier, the group can cause the paint film to undergo a cross-linking reaction in the air, so that the hardness of the paint film is significantly improved. If the addition of dicyclopentadiene increases, the hardness of the paint film can be increased to the 3H level, but it is worth noting that with the increase in the addition of dicyclopentadiene, the viscosity of the water-based epoxy ester resin will also increase therewith, and too high viscosity is not conducive to the production of water-based epoxy ester paint, and the greater the viscosity of the water-based epoxy ester resin, the higher the risk of its coking. In addition, with the continuous improvement of the hardness of the paint film, its tolerance time to 5% neutral salt spray is also extended therewith, which proves that the introduction of dicyclopentadiene improves the various properties of the paint film.

[0077] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0078] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0079] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A dicyclopentadiene modified waterborne epoxy ester resin, characterized in that: The preparation raw materials include the following components by weight: 2-6 parts of unsaturated acid, 1-5 parts of acrylate monomers, 0.1-1 parts of initiator, 40-65 parts of dicyclopentadiene modified epoxy resin intermediate, 10-30 parts of ethylene glycol monobutyl ether, and 20-25 parts of styrene.

2. The dicyclopentadiene modified waterborne epoxy ester resin according to claim 1, characterized in that: The unsaturated acid is at least one of acrylic acid, methacrylic acid and maleic acid.

3. The dicyclopentadiene modified waterborne epoxy ester resin according to claim 1, characterized in that: The acrylic acid ester monomer is at least one of butyl acrylate, methyl methacrylate and isooctyl acrylate.

4. The dicyclopentadiene modified waterborne epoxy ester resin according to claim 1, characterized in that: The initiator is at least one of benzoyl peroxide, tert-butyl perbenzoate, dicumyl peroxide and di-tert-butyl peroxide.

5. The dicyclopentadiene modified waterborne epoxy ester resin according to claim 1, characterized in that: The raw materials for preparing the dicyclopentadiene modified epoxy resin intermediate include the following components in parts by weight: 15-25 parts of vegetable fatty acid, 30-45 parts of epoxy resin, 15-25 parts of dicyclopentadiene adduct, 0.1-0.3 parts of xylene, and 15-20 parts of ethylene glycol monobutyl ether.

6. The dicyclopentadiene-modified waterborne epoxy ester resin according to claim 5, characterized in that: The preparation method of the dicyclopentadiene modified epoxy lipid intermediate comprises the following steps: A. Add dicyclopentadiene adduct, vegetable fatty acid, epoxy resin and xylene into the reactor according to the formula, heat to 150-170°C to start condensation reflux, continue to heat to 210-220°C, and carry out heat preservation reaction; B. When the acid value is less than or equal to 10 (mgKOH / g), remove xylene by vacuum distillation, then cool to 120-170°C, add ethylene glycol monobutyl ether, stir, filter, and obtain a dicyclopentadiene-modified epoxy resin intermediate.

7. The dicyclopentadiene-modified waterborne epoxy ester resin according to claim 5, characterized in that: The vegetable oil fatty acid is at least one of soybean oleic acid, linoleic acid, dehydrated ricinoleic acid and eleostearic acid.

8. The dicyclopentadiene-modified waterborne epoxy ester resin according to claim 5, characterized in that: The raw materials for preparing the dicyclopentadiene adduct include the following components in parts by weight: 55-65 parts of dicyclopentadiene, 30-35 parts of maleic anhydride, 5.5-7 parts of deionized water, and 0.008-0.01 parts of p-methoxyphenol.

9. The dicyclopentadiene-modified waterborne epoxy ester resin according to claim 8, characterized in that: The preparation method of the dicyclopentadiene adduct comprises: adding dicyclopentadiene, maleic anhydride and p-methoxyphenol into a reactor according to the formula amount, mixing, heating to 100-120° C., starting to drop deionized water, and keeping the temperature after the drop addition is completed until the acid value is less than or equal to 135 (mgKOH / g), thereby obtaining the dicyclopentadiene adduct.

10. A method for preparing a dicyclopentadiene-modified waterborne epoxy ester resin according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. The unsaturated acid, the acrylate monomer, the initiator and the styrene are mixed to obtain a mixture; S2. Add the dicyclopentadiene modified epoxy resin intermediate into the reactor, heat to 130-150°C, add dropwise the mixture obtained in step S1 while stirring, and keep warm after the addition is complete; S3. After the heat preservation is completed, the temperature is lowered, ethylene glycol monobutyl ether is added to adjust the solid content, and the mixture is filtered to obtain a dicyclopentadiene-modified water-based epoxy ester resin.

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