A flame-retardant epoxy vinyl ester resin and its preparation method

Abstract

The present invention discloses a flame-retardant epoxy vinyl ester resin and a preparation method thereof, belonging to the technical field of flame-retardant materials; the flame-retardant epoxy vinyl ester resin comprises the following components in parts by weight: 50-100 parts of epoxy vinyl ester resin, 1-10 parts of curing agent, 0.5-1.5 parts of accelerator, and 10-20 parts of modified talc powder; by adding modified talc powder to the formula, the mechanical and flame-retardant properties of the epoxy vinyl ester resin are significantly improved, and it can be applied to the field of flue gas desulfurization with high requirements for flame-retardant performance.

Description

Technical Field

[0001] The present invention relates to the technical field of flame retardant materials, and particularly relates to a flame retardant epoxy vinyl ester resin and a preparation method thereof. Background Art

[0002] Epoxy vinyl ester resin is prepared by the ring-opening addition chemical reaction of epoxy resin and unsaturated monobasic acid. It retains the basic chain segment of epoxy resin and has good process performance of unsaturated polyester resin. It inherits the excellent characteristics of epoxy resin, is more excellent in terms of curability and moldability, and can be dissolved in styrene and acrylic monomers. Due to having both the advantages of epoxy and unsaturation, its application fields are constantly expanding, and it is mainly applied in the chemical industry fields with demanding requirements such as chemical corrosion resistance, acid and alkali resistance, such as in the manufacture of new energy wind power generation, desulfurization and denitrification equipment in the environmental protection industry, the preparation of sewage pipes in the paper industry, and the applications in high-end fields such as cruise ships and high-speed rails. With the expansion of the application fields of vinyl ester resin, its application in some special fields requires flame retardant function, such as in the field of flue gas desulfurization.

[0003] Chinese patent document CN 110499004A discloses a ladder-shaped POSS modified vinyl ester resin containing both phenyl and vinyl and a preparation method thereof. The ladder-shaped POSS modified vinyl ester resin containing both phenyl and vinyl provided by this invention has good mechanical properties and low smoke and low heat release during the combustion process. The present invention provides a preparation method of the ladder-shaped POSS modified vinyl ester resin containing both phenyl and vinyl, with a simple process and short cycle, suitable for mass production. Only one flame retardant is added in the formula of this invention, and there is still room for further improvement in the mechanical and flame retardant properties of the vinyl ester resin prepared therefrom. Summary of the Invention

[0004] The main object of the present invention is to propose an epoxy vinyl ester resin with good mechanical and flame retardant properties. By adding modified talcum powder to the resin, the mechanical and flame retardant properties of the resin are significantly improved.

[0005] To achieve the above object, the present invention proposes a flame retardant epoxy vinyl ester resin, which comprises the following components in parts by weight: 50 - 100 parts of epoxy vinyl ester resin, 1 - 10 parts of curing agent, 0.5 - 1.5 parts of accelerator, and 10 - 20 parts of modified talcum powder.

[0006] Preferably, the curing agent is at least one of methyl ethyl ketone peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl perbenzoate, and cumene hydroperoxide.

[0007] Preferably, the accelerator is at least one of cobalt octoate, cobalt naphthenate, dimethylaniline, diethylaniline, dimethyl-p-toluidine, and triethylenediamine.

[0008] Preferably, the preparation method of the modified talc powder is as follows:

[0009] (1) Add talc powder to a 10 - 20 wt% dilute sulfuric acid aqueous solution, heat to 80 - 90 °C, react for 2 - 4 h, filter and collect the filter cake. Wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0010] (2) Prepare an aqueous solution of dopamine hydrochloride. Mix the pretreated talc powder with the aqueous solution of dopamine hydrochloride, then add Tris buffer solution, and react at 40 - 60 °C for 2 - 4 h. Filter and collect the solid, and dry to obtain polydopamine-coated talc powder;

[0011] (3) Disperse the polydopamine-coated talc powder in chloroform, add aminophenyl POSS, hydroxyethylidene diphosphonic acid, and epichlorohydrin, stir and mix evenly, and react at 50 - 80 °C for 4 - 6 h. After the reaction is completed, filter and collect the solid, and dry to obtain modified talc powder.

[0012] Preferably, in step (1), the dosage ratio of talc powder to dilute sulfuric acid solution is 1 - 2 g: 30 - 40 mL.

[0013] Preferably, in step (2), the concentration of the aqueous solution of dopamine hydrochloride is 20 - 30 wt%; the dosage ratio of the pretreated talc powder, the aqueous solution of dopamine hydrochloride to Tris buffer solution is 1 g: 10 - 20 mL: 1 - 3 mL.

[0014] Preferably, in step (3), the mass ratio of polydopamine-coated talc powder, aminophenyl POSS, hydroxyethylidene diphosphonic acid, and epichlorohydrin is 10 - 18: 5 - 8: 3 - 5: 6 - 10.

[0015] Talc powder is an inorganic nano flame retardant. Adding talc powder to epoxy vinyl ester resin can improve the flame retardancy of the resin. Treating talc powder with dilute sulfuric acid is beneficial to enhancing its reaction activity. Then coating it with polydopamine can introduce active amino groups on the surface of talc powder. Finally, under the action of epichlorohydrin, aminophenyl POSS and hydroxyethylidene diphosphonic acid are grafted onto the surface of talc powder. By modifying talc powder, the high surface free energy of talc powder is reduced, its polarity is decreased, and its uniform dispersion in epoxy vinyl ester resin is improved, thereby improving the mechanical properties of epoxy vinyl ester resin. At the same time, polydopamine, hydroxyethylidene diphosphonic acid, and aminophenyl POSS can form a nitrogen-silicon-phosphorus synergistic flame retardancy. Hydroxyethylidene diphosphonic acid plays a role in the condensed phase to promote the carbonization of the matrix, while polydopamine generates incombustible gases in the gas phase to achieve the synergistic flame retardant effect. In addition, the cage structure in aminophenyl POSS makes the flame retardancy and thermal stability of the resin more excellent.

[0016] The present invention also discloses a preparation method of the above flame-retardant epoxy vinyl ester resin, which comprises the following steps:

[0017] Weigh each component according to the formula. After mixing the epoxy vinyl ester resin and the modified talc powder, stir evenly at 50-70°C to obtain mixture 1. Control the temperature of mixture 1 at 20-40°C, add a promoter and a curing agent to mixture 1, mix and stir evenly, then perform vacuum degassing treatment and curing to obtain the flame-retardant epoxy vinyl ester resin.

[0018] Preferably, the conditions for the vacuum degassing treatment are a vacuum degree of -0.01 to -0.09 MPa and a degassing time of 3-5 min.

[0019] Preferably, the flame-retardant epoxy vinyl ester resin can be applied to the resin matrix of composite materials, anticorrosive coatings, petroleum, chemical industry, environmental protection, building construction, transportation, aerospace, and flue gas desulfurization technology fields.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] (1) The epoxy vinyl ester resin of the present invention uses modified talc powder as a flame retardant, which has strong flame retardancy, good thermal stability, good compatibility with vinyl ester resin, and does not contain halogens itself. It can achieve the effects of flame retardancy, low toxicity, and smoke suppression at the same time. The preparation method is simple, suitable for industrial production, and can be applied to the resin matrix of composite materials, anticorrosive coatings, petroleum, chemical industry, environmental protection, building construction, transportation, aerospace, flue gas desulfurization and technology fields;

[0022] (2) By modifying the talc powder, the present invention reduces the high free energy on the surface of the talc powder, reduces its polarity, improves its uniform dispersion in the epoxy vinyl ester resin, thereby improving the mechanical properties of the epoxy vinyl ester resin. At the same time, polydopamine, hydroxyethylidene diphosphonic acid, and aminophenyl POSS can form a nitrogen-silicon-phosphorus synergistic flame retardancy. Hydroxyethylidene diphosphonic acid plays a role in the condensed phase to promote the carbonization of the matrix, while polydopamine generates non-combustible gases in the gas phase to achieve the synergistic flame retardancy effect. In addition, the cage structure in aminophenyl POSS makes the flame retardancy and thermal stability of the resin more excellent. Specific Embodiments

[0023] To avoid repetition, the items used in the following examples are all commercially available products without special instructions, and the methods used are all conventional methods without special instructions.

[0024] The sources of some raw materials used in the present invention are as follows:

[0025] Epoxy vinyl ester resin, bisphenol A type, purchased from Shandong Ruiding Chemical Co., Ltd.

[0026] Talc powder, with a hardness of 5.5 HB and a density of 2.45 g / cm 3 , purchased from Marlene Mineral Products Processing Factory in Lingshou County.

[0027] Aminophenyl POSS, purchased from Angxing New Carbon Materials Co., Ltd. in Changzhou

[0028] Hydroxyethylidene diphosphonic acid, with the model number 220 - 552 - 8, purchased from Shandong New Kinetic Energy Chemical Co., Ltd.

[0029] Example 1

[0030] A preparation method of a flame - retardant epoxy vinyl ester resin, comprising the following steps:

[0031] Mix 70 g of bisphenol A epoxy vinyl ester resin and 16.5 g of modified talc powder, and stir evenly at 60 °C to obtain mixture 1; control the temperature of mixture 1 at 30 °C, add 1.2 g of cobalt isooctanoate and 6.8 g of methyl ethyl ketone peroxide to mixture 1, mix and stir evenly, and perform vacuum degassing treatment at a vacuum degree of - 0.06 MPa for 5 min and then cure to obtain the flame - retardant epoxy vinyl ester resin.

[0032] The preparation method of the modified talc powder is as follows:

[0033] (1) Add 16 g of talc powder to 350 mL of 20 wt% dilute sulfuric acid aqueous solution, heat to 80 °C and react for 3 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0034] (2) Prepare an aqueous solution of dopamine hydrochloride with a concentration of 30 wt%, mix 15 g of pretreated talc powder with 200 mL of dopamine hydrochloride aqueous solution, add 30 mL of Tris buffer solution, react at 50 °C for 3 h, filter and collect the solid matter and dry to obtain polydopamine - coated talc powder;

[0035] (3) Disperse 16.8 g of polydopamine - coated talc powder in 200 mL of chloroform, add 6.5 g of aminophenyl POSS, 4.3 g of hydroxyethylidene diphosphonic acid, and 8.2 g of epichlorohydrin, stir and mix evenly, react at 80 °C for 6 h, after the reaction is completed, filter, collect the solid matter and dry to obtain modified talc powder.

[0036] Example 2

[0037] A preparation method of a flame - retardant epoxy vinyl ester resin, comprising the following steps:

[0038] Mix 50 g of bisphenol A epoxy vinyl ester resin and 10.3 g of modified talc powder, and stir evenly at 50 °C to obtain mixture 1; control the temperature of mixture 1 to 20 °C, add 0.5 g of cobalt isooctanoate and 1.5 g of methyl ethyl ketone peroxide to mixture 1, mix and stir evenly, and carry out vacuum degassing treatment at a vacuum degree of -0.01 MPa for 3 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0039] The preparation method of the modified talc powder is as follows:

[0040] (1) Add 12 g of talc powder to 300 mL of 10 wt% dilute sulfuric acid aqueous solution, heat to 80 °C and react for 2 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0041] (2) Prepare a 20 wt% dopamine hydrochloride aqueous solution, mix 15 g of pretreated talc powder with 200 mL of dopamine hydrochloride aqueous solution, add 30 mL of Tris buffer solution, react at 50 °C for 3 h, filter and collect the solid, and dry to obtain polydopamine-coated talc powder;

[0042] (3) Disperse 10 g of polydopamine-coated talc powder in 200 mL of chloroform, add 5.3 g of amine phenyl POSS, 3 g of hydroxyethylidene diphosphonic acid, and 6 g of epichlorohydrin, stir and mix evenly, react at 50 °C for 6 h, after the reaction is completed, filter, collect the solid and dry to obtain modified talc powder.

[0043] Example 3

[0044] A preparation method of a flame-retardant epoxy vinyl ester resin, comprising the following steps:

[0045] Mix 100 g of bisphenol A epoxy vinyl ester resin and 20 g of modified talc powder, and stir evenly at 70 °C to obtain mixture 1; control the temperature of mixture 1 to 40 °C, add 1.5 g of cobalt isooctanoate and 10 g of methyl ethyl ketone peroxide to mixture 1, mix and stir evenly, and carry out vacuum degassing treatment at a vacuum degree of -0.09 MPa for 5 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0046] The preparation method of the modified talc powder is as follows:

[0047] (1) Add 20 g of talc powder to 400 mL of 20 wt% dilute sulfuric acid aqueous solution, heat to 90 °C and react for 2 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0048] (2) Prepare an aqueous solution of dopamine hydrochloride with a concentration of 20 wt%. Mix 15 g of pretreated talc powder with 200 mL of the dopamine hydrochloride aqueous solution, then add 30 mL of Tris buffer solution, and react at 50 °C for 3 h. Filter and collect the solid, and dry it to obtain polydopamine-coated talc powder;

[0049] (3) Disperse 18 g of polydopamine-coated talc powder in 200 mL of chloroform, add 8 g of amine phenyl POSS, 5 g of hydroxyethylidene diphosphonic acid, and 10 g of epichlorohydrin, stir and mix evenly, and react at 80 °C for 4 h. After the reaction is completed, filter and collect the solid, and dry it to obtain modified talc powder.

[0050] Comparative Example 1

[0051] A preparation method of a flame-retardant epoxy vinyl ester resin is similar to that of Example 1, except that the talc powder is not modified, and specifically includes the following steps:

[0052] Mix 70 g of bisphenol A epoxy vinyl ester resin and 16.5 g of talc powder, and stir evenly at 60 °C to obtain Mixture 1; control the temperature of Mixture 1 to 30 °C, add 1.2 g of cobalt isooctanoate and 6.8 g of methyl ethyl ketone peroxide to Mixture 1, mix and stir evenly, and carry out vacuum degassing treatment at a vacuum degree of -0.06 MPa for 5 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0053] Comparative Example 2

[0054] A preparation method of a flame-retardant epoxy vinyl ester resin is similar to that of Example 1, except that the pretreated talc powder in the modified talc powder is not coated with polydopamine, and specifically includes the following steps:

[0055] Mix 70 g of bisphenol A epoxy vinyl ester resin and 16.5 g of modified talc powder, and stir evenly at 60 °C to obtain Mixture 1; control the temperature of Mixture 1 to 30 °C, add 1.2 g of cobalt isooctanoate and 6.8 g of methyl ethyl ketone peroxide to Mixture 1, mix and stir evenly, and carry out vacuum degassing treatment at a vacuum degree of -0.06 MPa for 5 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0056] The preparation method of the modified talc powder is as follows:

[0057] (1) Add 16 g of talc powder to 350 mL of 20 wt% dilute sulfuric acid aqueous solution, heat to 80 °C and react for 3 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0058] (2) Disperse 16.8 g of pretreated talc powder in 200 mL of chloroform, add 6.5 g of amine phenyl POSS, 4.3 g of hydroxyethylidene diphosphonic acid, and 8.2 g of epichlorohydrin, stir and mix evenly, heat and stir at 80 °C for 6 h. After the reaction is completed, filter and collect the solid, and dry it to obtain modified talc powder.

[0059] Comparative Example 3

[0060] A preparation method of a flame-retardant epoxy vinyl ester resin is similar to that of Example 1, except that amine phenyl POSS is not added to the modified talc powder, and the specific steps are as follows:

[0061] Mix 70 g of bisphenol A epoxy vinyl ester resin and 16.5 g of modified talc powder, and stir evenly at 60 °C to obtain Mixture 1; control the temperature of Mixture 1 to 30 °C, add 1.2 g of cobalt isooctanoate and 6.8 g of methyl ethyl ketone peroxide to Mixture 1, mix and stir evenly, and carry out vacuum degassing treatment at a vacuum degree of -0.06 MPa for 5 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0062] The preparation method of the modified talc powder is as follows:

[0063] (1) Add 16 g of talc powder to 350 mL of 20 wt% dilute sulfuric acid aqueous solution, heat to 80 °C and react for 3 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and dry to obtain pretreated talc powder;

[0064] (2) Prepare an aqueous solution of dopamine hydrochloride with a concentration of 30 wt%, mix 15 g of pretreated talc powder with 200 mL of dopamine hydrochloride aqueous solution, add 30 mL of Tris buffer solution, and react at 50 °C for 3 h. Filter and collect the solid, and dry it to obtain polydopamine-coated talc powder;

[0065] (3) Disperse 16.8 g of polydopamine-coated talc powder in 200 mL of chloroform, add 4.3 g of hydroxyethylidene diphosphonic acid and 8.2 g of epichlorohydrin, stir and mix evenly, stir at 80 °C for 6 h. After the reaction is completed, filter and collect the solid, and dry it to obtain modified talc powder.

[0066] Comparative Example 4

[0067] A preparation method of a flame-retardant epoxy vinyl ester resin is similar to that of Example 1, except that hydroxyethylidene diphosphonic acid is not added to the modified talc powder, and the specific steps are as follows:

[0068] Mix 70 g of bisphenol A epoxy vinyl ester resin and 16.5 g of modified talc powder, and stir evenly at 60 °C to obtain Mixture 1; control the temperature of Mixture 1 at 30 °C, add 1.2 g of cobalt isooctanoate and 6.8 g of methyl ethyl ketone peroxide to Mixture 1, mix and stir evenly, and perform vacuum degassing treatment at a vacuum degree of -0.06 MPa for 5 min, and then cure to obtain the flame-retardant epoxy vinyl ester resin.

[0069] The preparation method of the modified talc powder is as follows:

[0070] (1) Add 16 g of talc powder to 350 mL of 20 wt% dilute sulfuric acid aqueous solution, heat to 80 °C and react for 3 h, filter and collect the filter cake, wash the filter cake with water until the pH value is neutral, and then dry to obtain pretreated talc powder;

[0071] (2) Prepare a dopamine hydrochloride aqueous solution with a concentration of 30 wt%, mix 15 g of pretreated talc powder with 200 mL of dopamine hydrochloride aqueous solution, add 30 mL of Tris buffer solution, react at 50 °C for 3 h, filter and collect the solid matter, and dry to obtain polydopamine-coated talc powder;

[0072] (3) Disperse 16.8 g of polydopamine-coated talc powder in 200 mL of chloroform, add 6.5 g of amine phenyl POSS and 8.2 g of epichlorohydrin, stir and mix evenly, stir at 80 °C for 6 h, after the reaction is completed, filter, collect the solid matter, and dry to obtain modified talc powder.

[0073] Performance testing

[0074] Pour the flame-retardant epoxy vinyl ester resins prepared in Examples 1-3 and Comparative Examples 1-4 into a mold according to the standard size to prepare test specimens. The smoke density is tested according to the ISO5659-2 standard, and a 50 kW / m radiation cone is selected 2 、flameless; the heat release test is carried out using a cone calorimeter according to the ISO5660-1 standard, and the radiation power is 50 kW / m 2 ; the mechanical properties of the resin casting are tested according to the GB / T2567-2021 standard, and the specimen size is 100 mm × 15 mm × 4 mm. The performance test results of the flame-retardant epoxy vinyl ester resin are shown in Table 1:

[0075] Table 1 Performance test results of flame-retardant epoxy vinyl ester resin

[0076]

[0077]

[0078] It can be seen from the experimental data in Table 1 that the flame-retardant epoxy vinyl ester resin prepared in the embodiment of the present invention has good mechanical and flame-retardant properties.

[0079] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A flame retardant epoxy vinyl ester resin, characterized in that: The invention comprises the following components in parts by weight: 50-100 parts of epoxy vinyl ester resin, 1-10 parts of curing agent, 0.5-1.5 parts of accelerator, and 10-20 parts of modified talc; The preparation method of the modified talcum powder is as follows: (1) adding talc powder to a 10-20wt% dilute sulfuric acid aqueous solution, heating to 80-90°C and reacting for 2-4h, filtering and collecting the filter cake, washing the filter cake with water until the pH value is neutral, and then drying to obtain pretreated talc powder; (2) preparing a dopamine hydrochloride aqueous solution, mixing the pretreated talc powder with the dopamine hydrochloride aqueous solution, adding a Tris buffer, reacting at 40-60° C. for 2-4 hours, filtering and collecting the solid, and drying to obtain a polydopamine-coated talc powder; (3) Dispersing the polydopamine-coated talc in chloroform, adding aminophenyl POSS, hydroxyethylidene diphosphonic acid, and epichlorohydrin, stirring and mixing evenly, reacting at 50-80°C for 4-6 hours, and after the reaction is completed, filtering, collecting the solids, and drying to obtain modified talc.

2. The flame retardant epoxy vinyl ester resin according to claim 1, characterized in that: The curing agent is at least one of methyl ethyl ketone peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl perbenzoate, and cumene hydroperoxide.

3. The flame retardant epoxy vinyl ester resin according to claim 1, characterized in that: The accelerator is at least one of cobalt isooctanoate, cobalt naphthenate, dimethylaniline, diethylaniline, dimethyl-p-methylaniline and triethylenediamine.

4. The flame retardant epoxy vinyl ester resin according to claim 1, characterized in that: In the step (1), the ratio of talcum powder to dilute sulfuric acid solution is 1-2 g: 30-40 mL.

5. The flame retardant epoxy vinyl ester resin according to claim 1, characterized in that: The concentration of the dopamine hydrochloride aqueous solution in step (2) is 20-30wt%; the dosage ratio of the pretreated talcum powder, dopamine hydrochloride aqueous solution and Tris buffer is 1g:10-20mL:1-3mL.

6. The flame retardant epoxy vinyl ester resin according to claim 1, characterized in that: In the step (3), the mass ratio of polydopamine-coated talcum powder, aminophenyl POSS, hydroxyethylidene diphosphonic acid, and epichlorohydrin is 10-18:5-8:3-5:6-10.

7. A method for preparing the flame retardant epoxy vinyl ester resin according to any one of claims 1 to 6, characterized in that: The steps include: Weigh each component according to the formula, mix the epoxy vinyl ester resin and modified talc, and stir evenly at 50-70° C. to obtain a mixture 1; control the temperature of the mixture 1 to be 20-40° C., add an accelerator and a curing agent to the mixture 1, mix and stir evenly, perform vacuum degassing treatment, and cure to obtain the flame-retardant epoxy vinyl ester resin.

8. The preparation method according to claim 7, characterized in that: The vacuum degassing treatment conditions are as follows: vacuum degree is -0.01~-0.09MPa, and degassing time is 3-5min.

9. Use of the flame retardant epoxy vinyl ester resin according to any one of claims 1 to 6, characterized in that: Used in resin matrix of composite materials, anti-corrosion coatings, petroleum, chemical industry, environmental protection, housing construction, transportation, aerospace and flue gas desulfurization technology fields.

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