Halogen-free flame-retardant vinyl ester resin and preparation method therefor, and composite resin

Abstract

The present invention relates to the field of organic polymer compounds, in particular to the field of C08 G 59 / 00, and more specifically to a halogen-free flame-retardant vinyl ester resin and a preparation method therefor, and a composite resin. The raw materials for preparing the composite resin at least comprise, in mass percent, 30-45% of a halogen-free flame-retardant vinyl ester resin, 40-50% of a high-temperature-resistant vinyl ester resin, 0.02-0.05% of a second polymerization inhibitor, 10-20% of a crosslinkable monomer, and 0-20% of an additive flame retardant, wherein the raw materials for preparing the halogen-free flame-retardant vinyl ester resin at least comprise, in mass percent, 40-60% of an epoxy resin, 13-18% of unsaturated monocarboxylic acid, 0.05-0.1% of a polymerization inhibitor, 0.5-0.7% of a catalyst, 24-35% of a crosslinking monomer, and 0.3-0.7% of a coupling agent. The composite resin provided by the present invention is resistant to high temperature and free of halogen, and has excellent mechanical properties and a simple and environmentally-friendly preparation process.

Description

Halogen-free flame-retardant vinyl ester resin, preparation method thereof, and composite resin Technical Field

[0001] The present invention belongs to the field of organic polymer compounds, in particular to the field of C08G59 / 00, and more specifically to a halogen-free flame-retardant vinyl ester resin, a preparation method thereof, and a composite resin. Background Art

[0002] Vinyl ester resin is made from epoxy resin and an unsaturated monocarboxylic acid containing double bonds. In the presence of catalysts and other additives, a ring-opening esterification reaction occurs during heating to produce oligomers containing unsaturated double bonds at either the terminal or pendant groups. This oligomer is then dissolved in a cross-linking monomer to form a free-radical-curing thermosetting resin. Vinyl ester resin combines the excellent corrosion resistance and mechanical properties of epoxy resin with the ease of processing and molding of unsaturated polyester resin. It has become the primary matrix material for corrosion-resistant fiberglass reinforced plastics (FRP) products and is widely used in various sectors of the national economy, including chemical engineering, metallurgy, and construction. However, due to its low oxygen index, typically only 19.8%, vinyl epoxy resin is flammable, making it difficult to meet the demands of specialized applications such as rail transit and shipping. Furthermore, the combustion process releases large amounts of toxic smoke, posing a serious safety hazard. Research has shown that adding flame retardants to the resin matrix can significantly improve its flame retardancy. The current mainstream solutions are as follows: 1) Additive flame retardants are dispersed into polymer materials through physical blending to exert their flame retardant effect. Additive flame retardants are widely used because they are used in large quantities and are relatively easy to handle. However, they generally have poor solubility in the matrix and are prone to phase separation during the curing process, making it difficult to achieve stable and balanced flame retardancy and mechanical properties. 2) Through molecular structure design or chemical modification, flame retardant elements are added to the reacting raw materials. These elements then react during the polymerization process and are incorporated into the main chain or side chain of the polymer, exerting a flame retardant effect. Reactive flame retardants are characterized by good flame retardant stability, are not easily lost, and have minimal impact on the material, but their operation and processing are relatively complex. Currently, the reactive flame retardant resins widely used on the market contain halogens, which are incompatible with halogen-free, environmentally friendly flame retardant technologies. However, as people become more environmentally conscious, many countries around the world have banned the use of halogen-containing flame retardants, as they release large amounts of corrosive and harmful gases during combustion. Furthermore, the high-temperature resistance of traditional vinyl resins is insufficient, making them inadequate for high-temperature use, limiting their scope of application. Therefore, developing a high-temperature-resistant, halogen-free, flame-retardant vinyl resin with a simple preparation process and easy industrialization is of great significance.

[0003] Prior art: Patent CN107383337A discloses a halogen-free flame-retardant vinyl ester resin, whose raw materials include phosphorus-containing epoxy resin, unsaturated monobasic acid, catalyst, polymerization inhibitor, and cross-linkable monomer. This vinyl ester resin does not produce toxic halogen-containing gases when burned, thus resolving the problem of deteriorating the physical properties of the composite material. Prior art: Patent CN111454463B discloses a flame-retardant phosphorylated carbon nanotube-modified acrylic resin material, whose raw materials include phosphorylated carbon nanotubes, epoxy resin, styrene, methyl methacrylate, methacrylic acid, etc. This acrylic resin material not only solves the problem of poor raw material compatibility but also has good flame retardant properties. However, these inventions struggle to simultaneously achieve strong flame retardancy, excellent mechanical properties, and low production costs.

[0004] Summary of the Invention

[0005] In order to solve the above problems, the first aspect of the present invention provides a halogen-free flame retardant vinyl ester resin, the preparation raw materials of which include at least: 40-60% epoxy resin, 13-18% unsaturated monocarboxylic acid, 0.05-0.1% inhibitor, 0.5-0.7% catalyst, 24-35% cross-linking monomer, and 0.3-0.7% coupling agent in percentage by mass.

[0006] Preferably, the epoxy resin includes at least one of halogen-free flame-retardant epoxy resin, phenol biphenyl epoxy resin, phenol aralkane epoxy resin, and dicyclopentadiene phenol epoxy resin.

[0007] Further preferably, the epoxy resin includes at least one of phenol biphenyl epoxy resin, dicyclopentadiene phenol epoxy resin, and halogen-free flame retardant epoxy resin.

[0008] Preferably, the unsaturated monocarboxylic acid includes at least one of methacrylic acid, acrylic acid, and crotonic acid.

[0009] More preferably, the unsaturated monocarboxylic acid includes at least one of acrylic acid and methacrylic acid.

[0010] Preferably, the polymerization inhibitor includes at least one or more of tert-butylhydroquinone, 4-tert-butylcatechol, p-benzoquinone, hydroquinone, methylhydroquinone, and p-hydroxyanisole.

[0011] More preferably, the polymerization inhibitor includes p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone.

[0012] More preferably, the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is (3-6): (0.1-3): (0.5-4).

[0013] As an implementable solution, the mass ratios of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone may include 5.2:0.7:3.8, 5:0.7:3.7, 3.8:2.7:0.6, and 3.7:2.6:0.6.

[0014] Preferably, the catalyst includes at least one or more of trimethylamine, dimethyl sulfide, diethylene glycol dimethyl ether, triphenylphosphine, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyldimethylamine, imidazole, 1-methylimidazole, 2-ethyl-4-methylimidazole, and 2-heptadecylimidazole.

[0015] More preferably, the catalyst includes at least triphenylphosphine and benzyltrimethylammonium chloride.

[0016] More preferably, the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is (1-3):(4-6).

[0017] As an implementable case, the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride may include 2:5.9, 1.94:5.8, 1.5:4.4, and 1.5:4.3.

[0018] Preferably, the cross-linking monomer includes at least one or more of styrene, vinyltoluene, divinylbenzene, diallyl phthalate, TAIC, methyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and neopentyl glycol dimethacrylate.

[0019] Further preferably, the cross-linking monomer includes at least styrene.

[0020] Preferably, the coupling agent includes at least one or more of methyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, maleic acid amidopropyltriethoxysilane, and aminoethylaminopropyltrimethoxysilane.

[0021] More preferably, the coupling agent at least includes γ-(methacryloyloxy)propyltrimethoxysilane.

[0022] The present invention utilizes specific raw materials to produce a halogen-free flame-retardant vinyl ester resin. The main polymer components include an epoxy resin, an unsaturated monocarboxylic acid, and a crosslinking monomer. The epoxy resin and the unsaturated monocarboxylic acid containing double bonds are used as starting materials. In the presence of a catalyst and other additives, a ring-opening esterification reaction is performed by heating to produce oligomers containing unsaturated double bonds at the end or side groups. This oligomer is then dissolved in the crosslinking monomer to produce a free-radical-cured thermosetting resin. This resin combines the excellent corrosion resistance and mechanical properties of epoxy resins with the convenient processing and molding properties of unsaturated polyester resins. Wherein crosslinking monomer comprises vinylbenzene at least, and vinylbenzene is comparatively active, can polymerize at normal temperatures, therefore uses the polymerization inhibitor of single component to be difficult to effectively polymerization inhibition; P-Hydroxyanisole is the commonly used polymerization inhibitor of acrylic acid and ester monomer thereof, thereby it can catch free radical effectively and stop the carrying out of free radical chain reaction, its advantage is that the monomer that does not remove this polymerization inhibitor still can participate in polymerization, and little on the influence of polyreaction; The polyphenol type polymerization inhibitor inhibition is actually antioxidant, and easily oxidized to the phenol of quinone type structure, it is large as the reactive activity of Resorcinol and peroxy radical, and the inhibition activity is high, having the electron-pushing group on the phenyl ring such as 4-tert-butylcatechol then makes the reactive activity with peroxy radical high, and the inhibition activity is also strong, and the inhibition effect of tert-butylcatechol at high temperature is very poor, but at lower temperature slightly, its inhibition effect is 25 times higher than Resorcinol. The invention selects polyphenol polymerization inhibitors 4-tert-butylcatechol, hydroquinone and p-hydroxyanisole for compounding, and when the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol and hydroquinone is (3-6): (0.1-3): (0.5-4), not only can the polymerization be better inhibited, but also the progress of other reactions will not be affected, and the polymerization inhibition effect can be achieved even at high temperature. The polymerization inhibition effect of the compounded polymerization inhibitor is about 300 times that of a single polymerization inhibitor. By using the limited polymerization inhibitor, a halogen-free flame-retardant vinyl ester resin with a suitable molecular weight can be obtained, and the oxygen index of the resin can reach more than 32%. After being used as a raw material for preparing a composite resin, the resin can provide the composite resin with excellent flame retardant performance.

[0023] A second aspect of the present invention provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0024] Put the epoxy resin into the reactor, keep it warm at 80±2°C and stir to melt, then add the unsaturated monocarboxylic acid and the polymerization inhibitor, keep it warm at 80±2°C, stir for 0.3-0.8h, then add the catalyst, turn on the cooling water, control the heating rate of the reactor to be 18-22°C / h, and finally the reactor temperature reaches 115±2°C. Starting from the temperature reaching 105-110°C, test the epoxy value and acid value every 0.3-0.8h. The reaction end point is when the epoxy value is less than 0.02mol / 100g and the acid value is less than 14mgKOH / g. Then cool the temperature to 75-85°C, add the polymerization inhibitor, cross-linking monomer and coupling agent according to the mass ratio, and continue stirring for 0.5-1.0h to obtain a halogen-free flame retardant vinyl ester resin.

[0025] The third aspect of the present invention provides a composite resin, wherein the raw materials for preparing the composite resin include at least 30-45% halogen-free flame-retardant vinyl ester resin, 40-50% high-temperature resistant vinyl ester resin, 0.02-0.05% second polymerization inhibitor, 10-20% cross-linkable monomer, and 0-20% additive flame retardant in percentage by mass.

[0026] Preferably, the second polymerization inhibitor includes at least one of hydroquinone, 4-tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidinoxide, p-benzoquinone, p-hydroxyanisole and o-methylhydroquinone.

[0027] More preferably, the second polymerization inhibitor at least includes o-methylhydroquinone.

[0028] Preferably, the crosslinkable monomer includes at least one of styrene, trimethylolpropane triacrylate, trimethylolpropane tri(methacrylate), pentaerythritol triacrylate and dipentaerythritol hexaacrylate.

[0029] More preferably, the crosslinkable monomers are pentaerythritol triacrylate and trimethylolpropane triacrylate.

[0030] Preferably, the additive flame retardant includes at least one of antimony trioxide, aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, dimethyl methyl phosphate, triphenyl phosphate and DOPO.

[0031] As an implementable example, the additive flame retardant may include aluminum hydroxide.

[0032] The preparation method of the composite resin comprises the steps of uniformly mixing various raw materials.

[0033] The composite resin prepared by the present invention is prepared by compounding and cross-linking a halogen-free flame-retardant vinyl ester resin and a high-temperature resistant vinyl ester resin. The oxygen index of the halogen-free flame-retardant vinyl ester resin can reach 32%. The compounded composite resin not only has good flame retardancy, but also has an oxygen index of more than 28%. It is also resistant to high temperatures, with a glass transition temperature (Tg) of more than 190°C. In addition, the introduction of a cross-linkable monomer can further improve the mechanical properties of the composite resin, thereby extending the service life of the composite resin. The preparation method of the composite resin described in the present invention is simple, requiring only the uniform mixing of the raw materials. At the same time, the use of organic solvents is avoided, which not only enables low-cost and efficient preparation, but also is environmentally friendly. Beneficial effects

[0034] 1. The present invention synthesizes a halogen-free flame-retardant vinyl ester resin according to specific raw materials and their proportions. The oxygen index of the halogen-free flame-retardant vinyl ester resin can reach 32%. It can be blended with a high-temperature resistant vinyl ester resin to prepare a composite resin. The composite resin has good flame retardancy and an oxygen index of more than 28%. It is also resistant to high temperatures and has a glass transition temperature (Tg) of more than 190°C.

[0035] 2. The halogen-free flame-retardant vinyl ester resin prepared by the present invention has excellent flame retardant effect. Its own oxygen index can reach 32%. Moreover, since it does not contain halogen elements, it will not produce toxic halogen-containing gases at high temperatures and can be used in materials with high fire protection requirements.

[0036] 3. The molecular formula of the composite resin prepared by the present invention does not contain any halogen elements and is more environmentally friendly than the halogen-containing chemical flame-retardant vinyl ester resin on the market.

[0037] 4. The composite resin prepared by the present invention has excellent heat resistance and flame retardancy after compounding, and the mechanical properties and corrosion resistance do not decrease significantly.

[0038] 5. The composite resin prepared by the present invention has moderate viscosity and is suitable for composite material molding processes such as hand lay-up, vacuum infusion, resin transfer molding (RTM), pultrusion, etc., and has good wettability with carbon fiber or glass fiber.

[0039] 6. The composite resin of the present invention has a simple production process, low cost, and is easy to industrialize. The preparation process is relatively green and environmentally friendly, avoids the use of organic solvents, and has a good market promotion prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG1 is a DSC curve of the halogen-free flame-retardant vinyl ester resin prepared in Example 1, wherein the oxygen index of the halogen-free flame-retardant vinyl ester resin alone is 32%.

[0041] FIG2 is a DSC curve diagram of the composite resin prepared in Example 1.

[0042] FIG3 is a DSC curve diagram of the composite resin prepared in Example 2.

[0043] FIG4 is a DSC curve diagram of the composite resin prepared in Example 3.

[0044] FIG5 is a DSC curve diagram of the composite resin prepared in Example 4.

[0045] FIG6 is a DSC curve diagram of the composite resin prepared in Example 5.

[0046] FIG7 is a DSC curve diagram of the composite resin prepared in Example 6.

[0047] FIG8 is a DSC curve diagram of the composite resin prepared in Comparative Example 1.

[0048] FIG9 is a DSC curve diagram of the composite resin prepared in Comparative Example 1. DETAILED DESCRIPTION

[0049] Example 1

[0050] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are 56.8% epoxy resin, 16.9% unsaturated monocarboxylic acid, 0.086% polymerization inhibitor, 0.69% catalyst, 25% cross-linking monomer, and 0.524% coupling agent in percentage by mass.

[0051] The epoxy resin is phenol biphenyl epoxy resin SQXN-324 (purchased from Shandong Shengquan New Materials Co., Ltd.).

[0052] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0053] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 5.2:0.7:3.8.

[0054] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 2:5.9.

[0055] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0056] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0057] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0058] Phenol biphenyl epoxy resin was placed in a reactor and heated to 80°C to melt. Then, p-hydroxyanisole and 4-tert-butylcatechol were added and maintained at 80°C with stirring for 10 minutes. Methacrylic acid was added and stirred thoroughly. Triphenylphosphine and benzyltrimethylammonium chloride were then added. Cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final temperature reached 115°C. Starting at 110°C, the epoxy and acid values ​​were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.021 eq / 100g and the acid value dropped to 14 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0059] A third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin are as follows in percentage by mass: 34.99% halogen-free flame-retardant vinyl ester resin, 48.98% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, and 16% cross-linkable monomer.

[0060] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0061] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7.5:8.5.

[0062] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No.: 150-76-5) is added. The reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was stirred at room temperature for 5 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 5 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 5 hours. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0063] The composite resin is prepared by uniformly mixing the raw materials.

[0064] The DSC curve of the halogen-free flame-retardant vinyl ester resin prepared in this example is shown in FIG1 , wherein the oxygen index of the halogen-free flame-retardant vinyl ester resin alone is 32%.

[0065] The DSC curve of the composite resin prepared in this example is shown in FIG2 .

[0066] Example 2

[0067] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are 58.9% epoxy resin, 14.7% unsaturated monocarboxylic acid, 0.085% inhibitor, 0.70% catalyst, 25.16% cross-linking monomer, and 0.455% coupling agent in percentage by mass.

[0068] The epoxy resin is phenol biphenyl epoxy resin SQXN-324 (purchased from Shandong Shengquan New Materials Co., Ltd.).

[0069] The unsaturated monocarboxylic acid is acrylic acid (CAS No.: 79-10-7).

[0070] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 5.0:0.7:3.7.

[0071] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.94:5.8.

[0072] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0073] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0074] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0075] Phenol biphenyl epoxy resin was placed in a reactor and heated to 80°C to melt. Then, p-hydroxyanisole and 4-tert-butylcatechol were added and maintained at 80°C with stirring for 10 minutes. Acrylic acid was added and stirred thoroughly. After adding triphenylphosphine and benzyltrimethylammonium chloride, the cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final reactor temperature reached 115°C. Starting at 110°C, the epoxy value and acid value were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.021 eq / 100g and the acid value dropped to 15 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0076] A third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin include 34.99% halogen-free flame-retardant vinyl ester resin, 48.98% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, and 16% cross-linkable monomer.

[0077] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0078] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7.5:8.5.

[0079] The additive flame retardant is aluminum hydroxide (CAS No.: 21645-51-2).

[0080] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0081] The composite resin is prepared by uniformly mixing the raw materials.

[0082] The DSC curve of the composite resin prepared in this example is shown in FIG3 .

[0083] Example 3

[0084] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are, by weight percentage, 56.84% epoxy resin, 16.91% unsaturated monocarboxylic acid, 0.085% polymerization inhibitor, 0.69% catalyst, 24.98% cross-linking monomer, and 0.495% coupling agent.

[0085] The epoxy resin is phenol biphenyl epoxy resin SQXN-324 (purchased from Shandong Shengquan New Materials Co., Ltd.).

[0086] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0087] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 5.2:0.7:3.8.

[0088] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 2:5.9.

[0089] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0090] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0091] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0092] Phenol biphenyl epoxy resin was placed in a reactor and heated to 80°C to melt. Then, p-hydroxyanisole and 4-tert-butylcatechol were added and maintained at 80°C with stirring for 10 minutes. Methacrylic acid was added and stirred thoroughly. Triphenylphosphine and benzyltrimethylammonium chloride were then added. Cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final temperature reached 115°C. Starting at 110°C, the epoxy and acid values ​​were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.021 eq / 100g and the acid value dropped to 14 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0093] The third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin are 30% halogen-free flame-retardant vinyl ester resin, 44.97% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, 15% cross-linkable monomer, and 10% additive flame retardant.

[0094] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0095] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7:8.

[0096] The additive flame retardant is aluminum hydroxide (model: ON-908) (CAS number: 21645-51-2).

[0097] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0098] The composite resin is prepared by uniformly mixing the raw materials.

[0099] The DSC curve of the composite resin prepared in this example is shown in FIG4 .

[0100] Example 4

[0101] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are, by weight percentage, 49.91% epoxy resin, 15.68% unsaturated monocarboxylic acid, 0.082% polymerization inhibitor, 0.68% catalyst, 33.11% cross-linking monomer, and 0.538% coupling agent.

[0102] The epoxy resin is dicyclopentadiene phenol epoxy resin and halogen-free flame retardant epoxy resin; the mass ratio of the dicyclopentadiene phenol epoxy resin to the halogen-free flame retardant epoxy resin is 26:16.96.

[0103] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0104] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 3.8:2.7:0.6.

[0105] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.5:4.4.

[0106] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0107] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0108] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0109] Dicyclopentadiene phenol epoxy resin and halogen-free flame-retardant epoxy resin were placed in a reactor, heated to 80°C and melted. Then, p-hydroxyanisole and 4-tert-butylcatechol were added. The mixture was kept at 80°C and stirred for 10 minutes. Methacrylic acid was added and, after stirring evenly, triphenylphosphine and benzyltrimethylammonium chloride were added. The cooling water was turned on and the reactor heating rate was controlled at 20°C / h, with the final reactor temperature reaching 115°C. Starting at 110°C, the epoxy value and acid value were tested every 0.5h. The reaction endpoint was reached when the epoxy value dropped to 0.02eq / 100g and the acid value dropped to 15mgKOH / g. The temperature was then lowered to 80°C, hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added, and stirring was continued for 1.0h to obtain a halogen-free flame-retardant vinyl ester resin.

[0110] A third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin are as follows in percentage by mass: 35.99% halogen-free flame-retardant vinyl ester resin, 47.48% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, and 16.5% cross-linkable monomer.

[0111] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0112] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 8.0:8.5.

[0113] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0114] The composite resin is prepared by uniformly mixing the raw materials.

[0115] The DSC curve of the composite resin prepared in this example is shown in FIG5 .

[0116] Example 5

[0117] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are 51.91% epoxy resin, 13.66% unsaturated monocarboxylic acid, 0.083% inhibitor, 0.7% catalyst, 33.11% cross-linking monomer, and 0.537% coupling agent in percentage by mass.

[0118] The epoxy resin is dicyclopentadiene phenol epoxy resin and halogen-free flame retardant epoxy resin; the mass ratio of the dicyclopentadiene phenol epoxy resin to the halogen-free flame retardant epoxy resin is 26:16.96.

[0119] The unsaturated monocarboxylic acid is acrylic acid (CAS No.: 79-10-7).

[0120] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 3.7:2.6:0.6.

[0121] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.5:4.3.

[0122] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0123] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0124] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0125] Dicyclopentadiene phenol epoxy resin and halogen-free flame-retardant epoxy resin were placed in a reactor and heated to 80°C to melt. Then, p-hydroxyanisole and 4-tert-butylcatechol were added and the mixture was maintained at 80°C with stirring for 10 minutes. Acrylic acid was added and stirred thoroughly. After that, triphenylphosphine and benzyltrimethylammonium chloride were added. The cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final temperature reached 115°C. Starting at 110°C, the epoxy and acid values ​​were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.02 eq / 100g and the acid value dropped to 15 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0126] A third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin are as follows in percentage by mass: 35.99% halogen-free flame-retardant vinyl ester resin, 47.48% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, and 16.5% cross-linkable monomer.

[0127] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0128] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 8.0:8.5.

[0129] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0130] The composite resin is prepared by uniformly mixing the raw materials.

[0131] The DSC curve of the composite resin prepared in this example is shown in FIG6 .

[0132] Example 6

[0133] The first aspect of this embodiment provides a halogen-free flame-retardant vinyl ester resin, the raw materials for its preparation are, by weight percentage, 49.91% epoxy resin, 15.68% unsaturated monocarboxylic acid, 0.082% polymerization inhibitor, 0.68% catalyst, 33.11% cross-linking monomer, and 0.538% coupling agent.

[0134] The epoxy resin is dicyclopentadiene phenol epoxy resin and halogen-free flame retardant epoxy resin; the mass ratio of the dicyclopentadiene phenol epoxy resin to the halogen-free flame retardant epoxy resin is 26:16.96.

[0135] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0136] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 3.8:2.7:0.6.

[0137] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.5:4.4.

[0138] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0139] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0140] A second aspect of this embodiment provides a method for preparing a halogen-free flame-retardant vinyl ester resin, comprising the following steps:

[0141] Dicyclopentadiene phenol epoxy resin and halogen-free flame-retardant epoxy resin were placed in a reactor, heated to 80°C and melted. Then, p-hydroxyanisole and 4-tert-butylcatechol were added. The mixture was kept at 80°C and stirred for 10 minutes. Methacrylic acid was added and stirred until uniform. Triphenylphosphine and benzyltrimethylammonium chloride were added. The cooling water was turned on and the reactor temperature was raised at a rate of 20°C / h until the final reactor temperature reached 115°C. Starting at 110°C, the epoxy value and acid value were tested every 0.5h. The reaction was terminated when the epoxy value dropped to 0.021eq / 100g and the acid value dropped to 14mgKOH / g. The temperature was then lowered to 80°C, hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added, and stirring was continued for 1.0h to obtain a halogen-free flame-retardant vinyl ester resin.

[0142] The third aspect of this embodiment provides a composite resin, wherein the raw materials for preparing the composite resin are as follows in percentage by mass: 30% halogen-free flame-retardant vinyl ester resin, 44.985% high-temperature resistant vinyl ester resin, 0.015% second polymerization inhibitor, 15% cross-linkable monomer, and 10% additive flame retardant.

[0143] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0144] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7:8.

[0145] The additive flame retardant is aluminum hydroxide (model: ON-908) (CAS number: 21645-51-2).

[0146] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0147] The composite resin is prepared by uniformly mixing the raw materials.

[0148] The DSC curve of the composite resin prepared in this example is shown in FIG7 .

[0149] Comparative Example 1

[0150] The first aspect of this comparative example provides a halogen-free flame retardant vinyl ester resin, the raw materials for its preparation are 54.01% epoxy resin, 18.27% unsaturated monocarboxylic acid, 0.09% inhibitor, 0.75% catalyst, 26.37% crosslinking monomer, and 0.51% coupling agent in percentage by mass.

[0151] The epoxy resin is a phosphorus-containing epoxy resin (DOPO-HQ type modified phenolic epoxy);

[0152] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0153] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 4.4:3.6:0.6.

[0154] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.9:5.6.

[0155] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0156] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0157] The second aspect of this comparative example provides a method for preparing a halogen-free flame-retardant vinyl ester resin, which comprises the following steps:

[0158] A phosphorus-containing epoxy resin was added to a reactor according to the appropriate ratio. The temperature was raised to 80°C and stirred for a period of time until the temperature stabilized. Then, p-hydroxyanisole and 4-tert-butylcatechol were added. The temperature was maintained at 80°C and stirred for 10 minutes. Methacrylic acid was added and stirred thoroughly. After that, triphenylphosphine and benzyltrimethylammonium chloride were added. The cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final temperature reached 115°C. Starting at 110°C, the epoxy value and acid value were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.025 eq / 100g and the acid value dropped to 14 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0159] The third aspect of this comparative example provides a composite resin, wherein the raw materials for preparing the composite resin are as follows in percentage by mass: 34.99% halogen-free flame-retardant vinyl ester resin, 48.98% high-temperature resistant vinyl ester resin, 0.03% second polymerization inhibitor, and 16% crosslinkable monomer.

[0160] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0161] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7.5:8.5.

[0162] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No. : 79-41-4), 1.13Kg of triphenylphosphine (CAS No.: 603-35-0) and 4.14Kg of benzyltrimethylammonium chloride (CAS No.: 56-93-9), open the cooling water, control the reactor heating rate to 20°C / h, and finally the reactor temperature reaches 115°C. Starting from the temperature reaching 110°C, the epoxy value and acid value are tested every 0.5h. The reaction endpoint is when the epoxy value drops to 0.02eq / 100g and the acid value drops to 14mgKOH / g, to obtain a high temperature resistant vinyl ester resin prepolymer. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0163] The composite resin is prepared by uniformly mixing the raw materials.

[0164] The DSC curve of the composite resin prepared in this comparative example is shown in FIG8 .

[0165] Comparative Example 2

[0166] The first aspect of this comparative example provides a halogen-free flame retardant vinyl ester resin, the raw materials for its preparation are 54.01% epoxy resin, 18.27% unsaturated monocarboxylic acid, 0.09% inhibitor, 0.75% catalyst, 26.37% crosslinking monomer, and 0.51% coupling agent in percentage by mass.

[0167] The epoxy resin is a phosphorus-containing epoxy resin (DOPO-HQ type modified phenolic epoxy);

[0168] The unsaturated monocarboxylic acid is methacrylic acid (CAS No.: 79-41-4).

[0169] The polymerization inhibitor is p-hydroxyanisole (CAS No.: 150-76-5), 4-tert-butylcatechol (CAS No.: 98-29-3), and hydroquinone (CAS No.: 123-31-9); the mass ratio of p-hydroxyanisole, 4-tert-butylcatechol, and hydroquinone is 4.4:3.6:0.6.

[0170] The catalyst is triphenylphosphine (CAS No.: 603-35-0) and benzyltrimethylammonium chloride (CAS No.: 56-93-9); the mass ratio of triphenylphosphine to benzyltrimethylammonium chloride is 1.9:5.6.

[0171] The cross-linking monomer is styrene (CAS No.: 100-42-5).

[0172] The coupling agent is γ-(methacryloyloxy)propyltrimethoxysilane (CAS No.: 2530-85-0).

[0173] The second aspect of this comparative example provides a method for preparing a halogen-free flame-retardant vinyl ester resin, which comprises the following steps:

[0174] A phosphorus-containing epoxy resin was added to a reactor according to the appropriate ratio. The temperature was raised to 80°C and stirred for a period of time until the temperature stabilized. Then, p-hydroxyanisole and 4-tert-butylcatechol were added. The temperature was maintained at 80°C and stirred for 10 minutes. Methacrylic acid was added and stirred thoroughly. After that, triphenylphosphine and benzyltrimethylammonium chloride were added. The cooling water was turned on and the reactor temperature was raised at a rate of 20°C / hour until the final temperature reached 115°C. Starting at 110°C, the epoxy value and acid value were measured every 0.5 hours. The reaction was terminated when the epoxy value dropped to 0.025 eq / 100g and the acid value dropped to 14 mgKOH / g. The temperature was then lowered to 80°C, and hydroquinone, styrene, and γ-(methacryloyloxy)propyltrimethoxysilane were added. Stirring was continued for 1.0 hour to obtain a halogen-free flame-retardant vinyl ester resin.

[0175] The third aspect of this comparative example provides a composite resin, the raw materials for preparing the composite resin are as follows in percentage by mass: 30% halogen-free flame retardant vinyl ester resin, 44.985% high temperature resistant vinyl ester resin, 0.015% second polymerization inhibitor, 15% crosslinkable monomer, and 10% additive flame retardant.

[0176] The second polymerization inhibitor is o-methylhydroquinone (CAS No.: 95-71-6).

[0177] The additive flame retardant is aluminum hydroxide (ON-908) (CAS No.: 21645-51-2).

[0178] The crosslinkable monomers are pentaerythritol triacrylate (CAS No.: 3524-68-3) and trimethylolpropane triacrylate (CAS No.: 15625-89-5), and the mass ratio of pentaerythritol triacrylate to trimethylolpropane triacrylate is 7:8.

[0179] The preparation method of the high temperature resistant vinyl ester resin is as follows: 279.7 kg of phenol novolac epoxy resin SQPN-048 (purchased from Shandong Shengquan New Materials Co., Ltd.) and 45.8 kg of multifunctional epoxy resin AG-80 (purchased from Shanghai Huayi Resin Co., Ltd.) are put into a reactor, heated to 80 ° C and melted, and then 0.22 kg of p-hydroxyanisole (CAS No.: 150-76-5) is added, kept warm at 80 ± 2 ° C, stirred for 0.5 h, and 161.7 kg of methacrylic acid (CAS No.: 150-76-5) is added. The reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was stirred at room temperature for 2 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was stirred at room temperature for 5 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 5 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 3 hours. The reaction mixture was stirred at room temperature for 5 hours. The temperature was lowered to 80°C, and 0.26 kg of 4-tert-butylcatechol (CAS No.: 98-29-3), 0.045 kg of hydroquinone (CAS No.: 123-31-9), 288.6 kg of styrene (CAS No.: 100-42-5), 150.9 kg of trimethylolpropane triacrylate (CAS No.: 15625-89-5), 47.4 kg of triallyl cyanurate (CAS No.: 101-37-1), and 5.0 kg of γ-(methacryloyloxy)propyltrimethoxysilane KH570 (CAS No.: 2530-85-0) were added. The mixture was stirred for 1 hour to obtain a high temperature resistant vinyl ester resin.

[0180] The composite resin is prepared by uniformly mixing the raw materials.

[0181] The DSC curve of the composite resin prepared in this comparative example is shown in FIG9 .

[0182] Performance Testing

[0183] 1. Glass transition temperature (Tg) test

[0184] Test object: Composite resins prepared in Examples 1-6 and Comparative Examples 1-2

[0185] Test standard: GB / T 19466.2-2004; perform in accordance with Plastics - Differential Scanning Calorimetry (DSC) Part 2 - Determination of Glass Transition Temperature, and record the results in Table 1

[0186] 2. Limiting oxygen index test

[0187] Test object: Composite resins prepared in Examples 1-6 and Comparative Examples 1-2

[0188] Test standard: GB / T2406.2-2009; perform the test according to Plastics - Determination of Combustion Behavior by Oxygen Index Method Part 2 - Room Temperature Test, and record the results in Table 1

[0189] Table 1

[0190] 3. Mechanical properties test

[0191] Test object: Composite resins prepared in Examples 1-6 and Comparative Examples 1-2

[0192] The test method and test results are shown in Table 2. Six samples of the heat-resistant vinyl ester resin of each embodiment and comparative example were prepared in parallel, and the average value was taken for the test.

[0193] Table 2

[0194] From the above data, it can be seen that the high-temperature resistant halogen-free flame-retardant vinyl ester resin has good flame retardant properties and can meet the requirements of flame retardancy. At the same time, it has almost no effect on the mechanical properties of the product and can be normally used in the application of flame-retardant vinyl ester resin fiberglass products.

Claims

1. A halogen-free flame-retardant vinyl ester resin, characterized in that: The raw materials for preparation at least include, by mass percentage, 40-60% of epoxy resin, 13-18% of unsaturated monocarboxylic acid, 0.05-0.1% of polymerization inhibitor, 0.5-0.7% of catalyst, 24-35% of crosslinking monomer and 0.3-0.7% of coupling agent.

2. The halogen-free flame-retardant vinyl ester resin according to claim 1, characterized in that: The epoxy resin at least includes one or more of halogen-free flame-retardant epoxy resin, phenol biphenyl epoxy resin, phenol aromatic alkane epoxy resin, and dicyclopentadiene phenol epoxy resin.

3. The halogen-free flame-retardant vinyl ester resin according to claim 1, characterized in that: The polymerization inhibitor includes p-hydroxyanisole, 4-tert-butylcatechol and hydroquinone.

4. The halogen-free flame-retardant vinyl ester resin according to claim 3, characterized in that: The mass ratio of p-hydroxyanisole, 4-tert-butylcatechol and hydroquinone is (3-6): (0.1-3): (0.5-4).

5. The halogen-free flame-retardant vinyl ester resin according to claim 1, characterized in that: The catalyst comprises at least one or more of trimethylamine, dimethyl sulfide, diethylene glycol dimethyl ether, triphenylphosphine, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyldimethylamine, imidazole, 1-methylimidazole, 2-ethyl-4-methylimidazole, and 2-heptadecylimidazole.

6. The halogen-free flame-retardant vinyl ester resin according to claim 1, characterized in that: The cross-linking monomers include at least one or more of styrene, vinyl toluene, divinyl benzene, diallyl phthalate, TAIC, methyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, and neopentyl glycol dimethacrylate.

7. A method for preparing a halogen-free flame-retardant vinyl ester resin according to any one of claims 1 to 6, characterized in that: The following steps are involved: Put the epoxy resin into the reactor, keep it warm at 80±2℃, stir and melt, add unsaturated monocarboxylic acid and inhibitor, keep it warm at 80±2℃, stir for 0.3-0.8h, then add the catalyst, turn on the cooling water, control the heating rate of the reactor to 18-22℃ / h, and finally the reactor temperature reaches 115±2℃. When the temperature reaches 105-110℃, test the epoxy value and acid value every 0.3-0.8h. The reaction end point is when the epoxy value is less than 0.02mol / 100g and the acid value is less than 14mgKOH / g. Then cool it to 75-85℃, add inhibitor, cross-linking monomer and coupling agent according to the mass ratio, and continue stirring for 0.5-1.0h to obtain halogen-free flame retardant vinyl ester resin.

8. A composite resin comprising the halogen-free flame-retardant vinyl ester resin according to any one of claims 1 to 6, characterized in that: The raw materials for preparing the composite resin include at least 30-45% of halogen-free flame-retardant vinyl ester resin, 40-50% of high-temperature resistant vinyl ester resin, 0.02-0.05% of a second polymerization inhibitor, 10-20% of a cross-linkable monomer, and 0-20% of an additive flame retardant in terms of mass percentage.

9. The composite resin according to claim 8, characterized in that The crosslinkable monomers include at least one or more of styrene, trimethylolpropane triacrylate, trimethylolpropane tri(methacrylate), pentaerythritol triacrylate and dipentaerythritol hexaacrylate.

10. The composite resin according to claim 8, characterized in that The second polymerization inhibitor includes at least one of hydroquinone, 4-tert-butylcatechol, 4-hydroxy-2,2,6,6-tetramethylpiperidinoxide, p-benzoquinone, p-hydroxyanisole and o-methylhydroquinone.

Images