Preparation method of solvent-free epoxy vinyl ester resin prepreg

Abstract

The invention discloses a preparation method of a solvent-free epoxy vinyl ester resin prepreg, and relates to the technical field of high polymer materials. According to the solvent-free epoxy vinyl ester resin prepreg prepared by the preparation method disclosed by the invention, a crosslinking monomer styrene is not introduced in the preparation process, so that volatilization and residue of styrene are reduced, and the solvent-free epoxy vinyl ester resin prepreg is environment-friendly, has high strength, is not added with solvents such as a styrene solution and the like, and can be used for preparing the solvent-free epoxy vinyl ester resin prepreg. And volatilization and residues in the preparation process are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a method for preparing a solvent-free epoxy vinyl ester resin prepreg. Background Art

[0002] Epoxy vinyl ester resin is a type of polymer with unsaturated double bonds at the end, which is synthesized from epoxy resin and unsaturated monobasic acid. The unsaturated monobasic acid is usually methacrylic acid or acrylic acid, and the epoxy resin is usually bisphenol A type or phenolic type epoxy resin. Epoxy vinyl ester resin is a thermosetting resin, which inherits the excellent properties of epoxy resin, has better curing and molding properties, and strong corrosion resistance.

[0003] Composite materials manufactured by continuous fiber prepreg have the advantages of high mechanical properties, good consistency, and hygienic working environment, and are widely used in high-tech fields such as aerospace. The demand for high-performance composite materials is increasing. At present, continuous fiber prepreg is mainly developed for aerospace equipment, and the manufactured composite components have excellent mechanical properties.

[0004] At present, when epoxy vinyl ester resin is used to prepare prepreg, styrene solution is mostly used, which causes more volatilization and residue, causing pollution. Therefore, the present invention studies and prepares a solvent-free epoxy vinyl ester resin for preparing solvent-free epoxy vinyl ester resin prepreg. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for preparing a solvent-free epoxy vinyl ester resin prepreg without a cross-linking monomer.

[0006] A technical solution proposed by the present invention to solve the above technical problems is: a method for preparing a solvent-free epoxy vinyl ester resin prepreg, comprising the following specific steps:

[0007] S1. The epoxy resin and the unsaturated monocarboxylic acid are heated to 90-100°C, stirred evenly, a catalyst is added, the temperature is raised to 120-130°C, the reaction is continued for 8-10 hours, an organic dicarboxylic acid anhydride is added, the reaction is continued for 1-2 hours, an inhibitor is added, the temperature is stirred evenly and cooled to obtain a solvent-free epoxy vinyl ester resin;

[0008] S2. After heating the epoxy vinyl ester resin obtained in step S1 to 60-90°C, add an initiator and a thickener, mix well and apply the mixture on a film, then cover the resin surface with glass fiber, and then cover it with another film coated with a solvent-free epoxy vinyl ester resin. Solvent-free epoxy vinyl ester resin prepreg is prepared by impregnation, degassing, compaction and aging.

[0009] Preferably, the epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin, and bisphenol S epoxy resin.

[0010] Preferably, the organic dicarboxylic acid anhydride is one or more of maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, glutaric anhydride, etc.; the unsaturated monocarboxylic acid is one or more of methacrylic acid, acrylic acid, crotonic acid, etc.

[0011] Preferably, the catalyst is one or more of benzylitrimethylammonium bromide, benzylitriphenylphosphine chloride, triphenylphosphine, and imidazole.

[0012] Preferably, the polymerization inhibitor is one or more of hydroquinone, p-benzoquinone and tert-butylcatechol; the thickener is one or more of magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, toluene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate.

[0013] Preferably, the initiator is a thermal initiator or an ultraviolet light initiator: the thermal initiator is one or more of tert-butyl perbenzoate, tert-butyl peroxyethyl octanoate, and benzoyl peroxide; the ultraviolet light initiator is one or more of methyl benzoylformate, hydroxyketone oligomer, phenyl dibenzophenone, and isopropylthioxanthone.

[0014] Preferably, the glass fiber is glass fiber cloth, glass fiber mat or chopped glass fiber filaments.

[0015] Preferably, the mass ratio of the epoxy resin, the unsaturated monocarboxylic acid, the catalyst and the organic dicarboxylic acid is 40-60:6-20:0.01-0.05:0-6.

[0016] Preferably, the mass ratio of the thickener, solvent-free epoxy vinyl ester resin and glass fiber cloth is 0.5-1:45-55:45-55, and the mass ratio of the thickener, solvent-free epoxy vinyl ester resin and glass fiber mat or chopped glass fiber yarn is 0.5-1.5:65-80:20-35; the amount of thermal initiator is 1.0% to 3.0% of the solvent-free epoxy vinyl ester resin, and the amount of ultraviolet light initiator is 0.1% to 0.5% of the solvent-free epoxy vinyl ester resin.

[0017] A technical solution proposed by the present invention to solve the above technical problems is: a prepreg prepared by a method for preparing a solvent-free epoxy vinyl ester resin prepreg.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0019] The solvent-free epoxy vinyl ester resin prepreg prepared by the present invention does not introduce a cross-linking monomer such as styrene during the preparation process. Instead, the epoxy vinyl ester resin is heated to a certain temperature to reduce its viscosity, thereby reducing the volatilization and residue of the cross-linking monomer. While being environmentally friendly, the solvent-free epoxy vinyl ester resin prepreg still has high strength. DETAILED DESCRIPTION

[0020] The present invention is described in detail below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above content of the present invention. Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art.

[0021] Example 1

[0022] The preparation method of solvent-free epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0023] The bisphenol A epoxy resin and methacrylic acid were heated to 90°C, stirred evenly, benyltrimethylammonium bromide was added, the temperature was raised to 120°C, and the reaction was continued for 10 hours. The mass ratio of bisphenol A epoxy resin, methacrylic acid, and benyltrimethylammonium bromide was 40:6:0.01. 200 ppm of hydroquinone was added, stirred evenly, and the temperature was lowered to obtain a solvent-free epoxy vinyl ester resin.

[0024] After the epoxy vinyl ester resin prepared in the above step is heated to 60° C., a thermal initiator tert-butyl perbenzoate and a thickener toluene diisocyanate are added, mixed evenly and coated on a film, and then glass fiber cloth is covered on the resin surface, the mass ratio of the initiator, toluene diisocyanate, solvent-free epoxy vinyl ester resin and glass fiber cloth is 0.5:0.5:45:55, and then covered with another film coated with solvent-free epoxy vinyl ester resin, and a solvent-free epoxy vinyl ester resin prepreg is prepared by impregnation, degassing, compaction and aging.

[0025] Example 2

[0026] The preparation method of solvent-free epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0027] The bisphenol A epoxy resin and methacrylic acid were heated to 92°C, stirred evenly, benyltrimethylammonium bromide was added, the temperature was raised to 120°C, reacted for 10 hours, maleic anhydride was added, the mass ratio of bisphenol A epoxy resin, methacrylic acid, benyltrimethylammonium bromide and maleic anhydride was 40:6:0.01:3, the reaction was continued for 1 hour, 200 ppm of hydroquinone was added, stirred evenly and cooled to obtain a solvent-free epoxy vinyl ester resin;

[0028] After the epoxy vinyl ester resin prepared in the above step is heated to 70° C., a thermal initiator tert-butyl perbenzoate and a thickener magnesium oxide are added, mixed evenly and coated on a film, and then glass fiber cloth is covered on the resin surface, the mass ratio of the initiator, magnesium oxide, solvent-free epoxy vinyl ester resin and glass fiber cloth is 0.6:0.5:50:50, and then covered with another film coated with solvent-free epoxy vinyl ester resin, and a solvent-free epoxy vinyl ester resin prepreg is prepared by impregnation, degassing, compaction and aging.

[0029] Example 3

[0030] The preparation method of solvent-free epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0031] The bisphenol F epoxy resin and methacrylic acid were heated to 95°C, stirred evenly, benyl triphenyl phosphine chloride was added, the temperature was raised to 125°C, reacted for 8 hours, phthalic anhydride was added, the mass ratio of bisphenol F epoxy resin, methacrylic acid, benyl triphenyl phosphine chloride and phthalic anhydride was 50:10:0.02:5, the reaction was continued for 1.5 hours, 200 ppm of p-benzoquinone was added, stirred evenly and cooled to obtain a solvent-free epoxy vinyl ester resin;

[0032] After heating the epoxy vinyl ester resin prepared in the above step to 80° C., adding ultraviolet light initiator hydroxyketone oligomer and thickener magnesium oxide, mixing evenly and coating on a film, then covering the resin surface with glass fiber felt, the mass ratio of initiator, magnesium oxide, solvent-free epoxy vinyl ester resin and glass fiber felt is 0.1:1.0:70:30, and then covering with another film coated with solvent-free epoxy vinyl ester resin, and preparing a solvent-free epoxy vinyl ester resin prepreg through impregnation, degassing, compaction and aging.

[0033] Example 4

[0034] The preparation method of solvent-free epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0035] The phenol novolac epoxy resin and acrylic acid were heated to 100°C, stirred evenly, triphenylphosphine was added, the temperature was raised to 125°C, and after reacting for 8 hours, tetrahydrophthalic anhydride was added, the mass ratio of phenol novolac epoxy resin, acrylic acid, triphenylphosphine and tetrahydrophthalic anhydride was 60:10:0.03:5, the reaction was continued for 2 hours, 200 ppm of tert-butyl catechol was added, stirred evenly and cooled to obtain a solvent-free epoxy vinyl ester resin;

[0036] After the epoxy vinyl ester resin prepared in the above step is heated to 90° C., an ultraviolet light initiator phenyl benzophenone and a thickener magnesium oxide are added, mixed evenly and coated on a film, and then short glass fiber filaments are evenly spread on the resin surface, and the mass ratio of the initiator, magnesium oxide, solvent-free epoxy vinyl ester resin and short glass fiber filaments is 0.15:1.0:70:30, and then covered with another film coated with solvent-free epoxy vinyl ester resin, and a solvent-free epoxy vinyl ester resin prepreg is prepared by impregnation, degassing, compaction and aging.

[0037] Comparative Example 1

[0038] The preparation method of the general solvent-based epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0039] Raise the temperature of bisphenol F epoxy resin and methacrylic acid to 95°C, stir evenly, add benyl triphenyl phosphine chloride, raise the temperature to 120°C, react for 8 hours, add phthalic anhydride, the mass ratio of bisphenol F epoxy resin, methacrylic acid, benyl triphenyl phosphine chloride and phthalic anhydride is 50:8:0.02:5, continue to react for 1.5 hours, add 0.02 times the mass of bisphenol F epoxy resin as inhibitor hydroquinone and 0.6 times the mass of bisphenol F epoxy resin as cross-linking monomer styrene, cool down and stir evenly to obtain a universal solvent-based epoxy vinyl ester resin;

[0040] Add ultraviolet light initiator hydroxyketone oligomer and thickener magnesium oxide to the epoxy vinyl ester resin prepared in the above step, mix well and apply on a film, then cover the resin surface with glass fiber cloth, the mass ratio of initiator, magnesium oxide, solvent-based epoxy vinyl ester resin and glass fiber cloth is 0.1:0.5:50:50, then cover with another film coated with solvent-based epoxy vinyl ester resin, and prepare solvent-based epoxy vinyl ester resin prepreg through impregnation, degassing, compaction and aging.

[0041] Comparative Example 2

[0042] The preparation method of the general solvent-based epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0043] The bisphenol F epoxy resin and methacrylic acid were heated to 95°C, stirred evenly, benyl triphenyl phosphine chloride was added, the temperature was raised to 125°C, reacted for 10 hours, phthalic anhydride was added, the mass ratio of bisphenol F epoxy resin, methacrylic acid, benyl triphenyl phosphine chloride and phthalic anhydride was 50:8:0.02:4, the reaction was continued for 1.5 hours, 0.02 times the mass of the bisphenol F epoxy resin as a polymerization inhibitor hydroquinone and 0.7 times the mass of the bisphenol F epoxy resin as a cross-linking monomer styrene were added, the temperature was lowered and stirred evenly, and a universal solvent-based epoxy vinyl ester resin was prepared;

[0044] Add thermal initiator tert-butyl perbenzoate and thickener magnesium oxide to the epoxy vinyl ester resin prepared in the above step, mix well and apply on a film, then cover the resin surface with glass fiber mat, the mass ratio of initiator, magnesium oxide, solvent-based epoxy vinyl ester resin and glass fiber mat is 1.0:0.8:70:30, and then cover with another film coated with solvent-based epoxy vinyl ester resin, and prepare solvent-based epoxy vinyl ester resin prepreg through impregnation, defoaming, compaction and aging.

[0045] Comparative Example 3

[0046] The preparation method of the general solvent-based epoxy vinyl ester resin prepreg in this embodiment is as follows:

[0047] The bisphenol F epoxy resin and methacrylic acid were heated to 95°C, stirred evenly, benyl triphenyl phosphine chloride was added, the temperature was raised to 125°C, reacted for 10 hours, phthalic anhydride was added, the mass ratio of bisphenol F epoxy resin, methacrylic acid, benyl triphenyl phosphine chloride and phthalic anhydride was 50:8:0.02:4, the reaction was continued for 1.5 hours, 0.02 times the mass of the bisphenol F epoxy resin as a polymerization inhibitor hydroquinone and 0.8 times the mass of the bisphenol F epoxy resin as a cross-linking monomer styrene were added, the temperature was lowered and stirred evenly, and a universal solvent-based epoxy vinyl ester resin was prepared;

[0048] Add ultraviolet light initiator hydroxyketone oligomer and thickener magnesium oxide to the epoxy vinyl ester resin prepared in the above step, mix well and apply on a film, then evenly spread chopped glass fiber on the surface of the resin, the mass ratio of initiator, magnesium oxide, solvent-based epoxy vinyl ester resin and chopped glass fiber is 0.1:0.6:70:30, and then cover with another film coated with solvent-based epoxy vinyl ester resin, and prepare solvent-based epoxy vinyl ester resin prepreg by impregnation, degassing, compaction and aging.

[0049] Effect example

[0050] The solvent-free and general solvent-based epoxy vinyl ester resin prepregs prepared in the examples and comparative examples were cured into flat plates for mechanical property testing. Table 1 shows the performance analysis results of the epoxy vinyl ester resin prepregs prepared in Examples 1 to 4 of the present invention and Comparative Examples 1 to 3:

[0051] Table 1

[0052] Tensile strength(MPa) Bending strength(MPa) volatility Example 1 310 410 No volatile Example 2 285 380 No volatile Example 3 75 170 No volatile Example 4 70 160 No volatile Comparative Example 1 290 380 Styrene volatile Comparative Example 2 70 165 Styrene volatile Comparative Example 3 66 155 Styrene volatile

[0053] By comparing the experimental data of the examples with the comparative examples in Table 1, it can be clearly found that compared with the general solvent-based epoxy vinyl ester resin prepreg, the strength of the solvent-free epoxy vinyl ester resin prepreg prepared using Examples 1 to 4 is not reduced, and there is no styrene volatilization, which is environmentally friendly.

[0054] The solvent-free epoxy vinyl ester resin prepreg prepared by the present invention does not introduce a cross-linking monomer such as styrene during the preparation process, and there is no volatilization and residue of the cross-linking monomer. While being environmentally friendly, the solvent-free epoxy vinyl ester resin prepreg still has high strength.

[0055] Obviously, the above embodiments are merely examples for clearly illustrating the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. However, these obvious changes or modifications derived from the spirit of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for preparing a solvent-free epoxy vinyl ester resin prepreg, characterized in that: The specific steps include: S1. The epoxy resin and the unsaturated monocarboxylic acid are heated to 90-100°C, stirred evenly, a catalyst is added, the temperature is raised to 120-130°C, the reaction is continued for 8-10 hours, an organic dicarboxylic acid anhydride is added, the reaction is continued for 1-2 hours, an inhibitor is added, the mixture is stirred evenly and the temperature is lowered to obtain a solvent-free epoxy vinyl ester resin; S2. After heating the epoxy vinyl ester resin obtained in step S1 to 60-90°C, add an initiator and a thickener, mix well and apply the mixture on a film, then cover the resin surface with glass fiber, and then cover it with another film coated with a solvent-free epoxy vinyl ester resin. Solvent-free epoxy vinyl ester resin prepreg is prepared by impregnation, degassing, compaction and aging.

2. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The epoxy resin is one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin and bisphenol S epoxy resin.

3. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The organic dicarboxylic anhydride is one or more of maleic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, glutaric anhydride, etc.; the unsaturated monocarboxylic acid is one or more of methacrylic acid, acrylic acid, crotonic acid, etc.

4. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The catalyst is one or more of benzylitrimethylammonium bromide, benzylitriphenylphosphine chloride, triphenylphosphine and imidazole.

5. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The polymerization inhibitor is one or more of hydroquinone, p-benzoquinone and tert-butylcatechol; the thickener is one or more of magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, toluene diisocyanate, diphenylmethane diisocyanate and hexamethylene diisocyanate.

6. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The initiator is a thermal initiator or an ultraviolet light initiator: the thermal initiator is one or more of tert-butyl perbenzoate, tert-butyl peroxyethyl octanoate, and benzoyl peroxide; the ultraviolet light initiator is one or more of methyl benzoylformate, hydroxyketone oligomer, phenyl dibenzophenone, and isopropylthioxanthone.

7. The method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1, characterized in that: The glass fibers are glass fiber cloth, glass fiber mat or chopped glass fiber filaments.

8. A method for preparing a solvent-free epoxy vinyl ester resin prepreg according to any one of claims 1 to 7, characterized in that: The mass ratio of the epoxy resin, the unsaturated monocarboxylic acid, the catalyst and the organic dicarboxylic acid is 40-60:6-20:0.01-0.05:0-6.

9. A method for preparing a solvent-free epoxy vinyl ester resin prepreg according to any one of claims 1 to 7, characterized in that: The mass ratio of the thickener, solvent-free epoxy vinyl ester resin and glass fiber cloth is 0.5-1:45-55:45-55, and the mass ratio of the thickener, solvent-free epoxy vinyl ester resin and glass fiber mat or chopped glass fiber yarn is 0.5-1.5:65-80:20-35; the amount of thermal initiator is 1.0%-3.0% of the solvent-free epoxy vinyl ester resin, and the amount of ultraviolet light initiator is 0.1%-0.5% of the solvent-free epoxy vinyl ester resin.

10. A prepreg prepared by the method for preparing a solvent-free epoxy vinyl ester resin prepreg according to claim 1.