High-efficiency halogen-free plastic flame-retardant additive and preparation method thereof

Abstract

The invention discloses a high-efficiency halogen-free plastic flame-retardant additive and a preparation method thereof, and relates to the technical field of plastic additives, the high-efficiency halogen-free plastic flame-retardant additive is prepared from the following raw materials by weight: 35-45 parts of a modified porous nanoscale flame-retardant oxide / expanded graphite compound, 8-10 parts of organic phosphinic acid metal salt, 10-12 parts of a phosphorus synergist, 10-12 parts of a nitrogen synergist, and 3-5 parts of a coupling agent; the modified porous nanoscale flame-retardant oxide / expanded graphite compound is a porous nanoscale flame-retardant oxide / expanded graphite compound co-modified by 3-[N, N-dimethyl-[2-(2-methylpropyl-2-enoyloxy) ethyl] ammonium] propane-1-sulfonic acid inner salt, 2, 4, 6-trivinyl boroxane and diphenyl (4-vinyl phenyl) phosphine oxide. The additive is good in environmental protection property, remarkable in flame retardant effect, small in addition amount, good in compatibility with a plastic matrix and small in negative influence on mechanical properties of plastics.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic additives, and particularly relates to a high-efficiency non-halogen plastic flame retardant additive and a preparation method thereof. Background Art

[0002] Plastics are increasingly widely used and have penetrated all aspects of people's production and life. They are one of the indispensable materials in human production activities. However, due to their chemical composition, many plastics are extremely flammable. Once a fire occurs, the consequences are very serious. A large amount of toxic and harmful gases are generated during the combustion process, posing an extremely huge threat to humans themselves and their surrounding environment. Therefore, in order to improve the fire prevention performance of plastic products, a certain amount of flame retardant additives are usually added during their processing and molding.

[0003] At present, the plastic flame retardant additives on the market mainly include halogen-based flame retardant additives, phosphorus-based flame retardant additives, nitrogen-based flame retardant additives, and inorganic flame retardant additives. When plastic products containing halogen-based flame retardant additives burn, a large amount of highly toxic and carcinogenic gases such as dioxins will be released. These gases will not only cause serious pollution to the atmospheric environment but also accumulate in organisms, posing a long-term threat to the ecological system and human health. Although pure phosphorus-based flame retardant additives can improve the flame retardant performance of plastics to a certain extent, their flame retardant efficiency is still relatively low compared to halogen-based flame retardant additives. Moreover, when the addition amount is large, it will affect the processing performance of plastics, resulting in a decline in the surface quality of plastic products, such as flow marks and reduced gloss. Nitrogen-based flame retardant additives usually need to be used in combination with other flame retardant additives. When used alone, the flame retardant effect is poor, and irritating odors may be generated during high-temperature decomposition, affecting the use experience of the product. Inorganic flame retardant additives have the advantages of low cost, non-toxicity, and smokelessness. However, due to their large addition amount and problems such as compatibility, they will significantly reduce the mechanical properties and performance stability of plastics, making plastic products brittle and the impact strength drop significantly, and it is difficult to meet the application scenarios with high requirements for the comprehensive performance of materials.

[0004] For example, the Chinese invention patent with the authorization announcement number CN112724468B discloses a composite environmental protection flame retardant for PP and PP flame retardant plastics, which is obtained by mixing dimethyl trimethylsilylmethylphosphonate, pentaerythritol melamine phosphate, magnesium hydroxide, aluminum hydroxide, antimony trioxide, magnesium sulfate whisker non-halogen flame retardant, and graphene. However, the addition amount of this composite environmental protection flame retardant is relatively large, and 20% needs to be added to have a better flame retardant effect. Moreover, the price of antimony trioxide is relatively high and its environmental friendliness is poor.

[0005] It can be seen that there is still a need in this field for a high-efficiency non-halogen plastic flame retardant additive with good environmental friendliness, significant flame retardant effect, small addition amount, good compatibility with the plastic matrix, and little negative impact on the mechanical properties of the plastic matrix, as well as a preparation method thereof. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a highly efficient non-halogen plastic flame retardant additive with excellent environmental protection, remarkable flame retardant effect, small addition amount, good compatibility with the plastic matrix, and little negative impact on the mechanical properties of the plastic matrix, and a preparation method thereof.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A highly efficient non-halogen plastic flame retardant additive is made from the following raw materials by weight: 35-45 parts of a modified porous nano-scale flame retardant oxide / expanded graphite composite, 8-10 parts of an organic metal hypophosphite, 10-12 parts of a phosphorus-based synergist, 10-12 parts of a nitrogen-based synergist, and 3-5 parts of a coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0009] Preferably, the coupling agent is any one or a combination of silane coupling agents KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0010] Preferably, the nitrogen-based synergist is one or more of melamine, melamine cyanurate, and ammonium polyphosphate.

[0011] Preferably, the phosphorus-based synergist is one or more of tricresyl phosphate, triphenyl phosphate, and resorcinol bis(diphenyl phosphate).

[0012] Preferably, the organic metal hypophosphite is aluminum hypophosphite.

[0013] Preferably, the preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite includes the following steps:

[0014] Step I: Disperse a zinc source, a silicon source, a magnesium source, a copper source, and a molybdenum source in an alcohol solvent, stir evenly, then slowly add sodium acetate, transfer the mixture to a hydrothermal reaction kettle with a polytetrafluoroethylene liner, and react at 195-220 °C for 15-20 h; take out the reaction kettle, wait for the reaction system to cool to room temperature, then wash it repeatedly with absolute ethanol and deionized water, then dry it in a vacuum drying oven at 85-95 °C for 10-20 h, and finally calcine it to obtain a porous nano-scale flame retardant oxide;

[0015] Step II: After uniformly mixing the porous nano-scale flame retardant oxide and expanded graphite, disperse them in N,N-dimethylformamide. Then add 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide and an initiator thereto. Under an inert gas atmosphere, stir and react at 60-70 °C for 3-5 hours. Then rotary evaporate to remove the solvent to obtain a modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0016] Preferably, in Step I, the zinc source is zinc nitrate; the silicon source is at least one of sodium silicate and silicon tetrachloride; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride.

[0017] Preferably, in Step I, the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent, and sodium acetate is (0.1-0.3):1:0.2:(0.1-0.3):0.1:(10-20):3.

[0018] Preferably, in Step I, the alcohol solvent is at least one of ethanol, ethylene glycol, and n-butanol.

[0019] Preferably, in Step I, the calcination temperature is 600-800 °C and the time is 4-6 h.

[0020] Preferably, in Step II, the mass ratio of the porous nano-scale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator is 3:1:(15-25):0.6:0.3:(0.3-0.5):(0.01-0.03).

[0021] Preferably, in Step II, the initiator is azobisisobutyronitrile.

[0022] Preferably, in Step II, the particle size of the expanded graphite is 100 mesh, the model is 8080200, and it is provided by Qingdao Baixing Graphite Co., Ltd.

[0023] Preferably, in Step II, the inert gas is any one of nitrogen, helium, neon, and argon.

[0024] Another object of the present invention is to provide a preparation method of the high-efficiency non-halogen plastic flame retardant aid, comprising the following steps: Mix each raw material according to weight parts, and ball mill and mix uniformly to obtain a high-efficiency non-halogen plastic flame retardant aid.

[0025] The beneficial effects produced by the above technical solutions are as follows:

[0026] (1) The preparation method of the high-efficiency non-halogen plastic flame retardant aid provided by the present invention only requires mixing the raw materials evenly. The process is simple, without special equipment, has high preparation efficiency, is suitable for continuous industrial production, and has high popularization and application value.

[0027] (2) The high-efficiency non-halogen plastic flame retardant aid provided by the present invention is made of the following raw materials by weight: 35-45 parts of modified porous nano-scale flame retardant oxide / expanded graphite composite, 8-10 parts of organic metal hypophosphite, 10-12 parts of phosphorus-based synergist, 10-12 parts of nitrogen-based synergist, and 3-5 parts of coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite. Through the synergistic effect of each raw material, the prepared flame retardant aid has good environmental protection, remarkable flame retardant effect, small addition amount, good compatibility with the plastic matrix, and little negative impact on the mechanical properties of the plastic matrix; it can form a stable carbonaceous layer on the plastic surface, effectively preventing the transfer of heat and oxygen, thereby significantly improving the flame retardant performance of the plastic. The high specific surface area of the modified porous nano-scale flame retardant oxide / expanded graphite composite can further improve the flame retardant effect; through the reasonable selection of its preparation raw materials and modifiers, the prepared flame retardant aid not only combines the advantages of various flame retardant active ingredients, but also can improve its compatibility with plastics, avoiding agglomeration or stratification during use, and then ensuring the processing performance and product quality of plastics.

[0028] (3) The high-efficiency non-halogen plastic flame retardant aid provided by the present invention does not contain halogens and is safer and more environmentally friendly to use; the modified porous nano-scale flame retardant oxide / expanded graphite composite uses zinc source, silicon source, magnesium source, copper source, molybdenum source and expanded graphite as raw materials, and uses 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide as modifiers, so that the prepared flame retardant contains not only inorganic flame retardant active ingredients, but also flame retardant active ingredient amphoteric organic ion salt, cyclotriboroxane and phenylphosphine oxide structures. Under the action of various effects such as electronic effect, steric effect and conjugation effect, these structures can effectively improve the flame retardant effect and at the same time improve the compatibility with plastics, so that it can still achieve good flame retardant effect under less usage amount, and further reduce the negative impact on the mechanical properties of plastics. Detailed implementation mode

[0029] To enable those skilled in the art to better understand the technical solution of the present invention and make the above features, objectives, and advantages of the present invention clearer and easier to understand, the present invention will be further described below in conjunction with embodiments. The embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0030] Example 1

[0031] An efficient non-halogen plastic flame retardant aid is made from the following raw materials by weight: 35 parts of modified porous nano-scale flame retardant oxide / expanded graphite composite, 8 parts of organic metal hypophosphite, 10 parts of phosphorus-based synergist, 10 parts of nitrogen-based synergist, and 3 parts of coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0032] The coupling agent is silane coupling agent KH550; the nitrogen-based synergist is melamine; the phosphorus-based synergist is tricresyl phosphate; the organic metal hypophosphite is aluminum hypophosphite.

[0033] The preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite includes the following steps:

[0034] Step I: Disperse zinc source, silicon source, magnesium source, copper source, and molybdenum source in an alcohol solvent, stir evenly, then slowly add sodium acetate, transfer the mixture to a hydrothermal reaction kettle lined with polytetrafluoroethylene, and react at 195 °C for 15 h; take out the reaction kettle, repeatedly wash with absolute ethanol and deionized water after the reaction system cools to room temperature, then dry in a vacuum drying oven at 85 °C for 10 h, and finally calcine to obtain a porous nano-scale flame retardant oxide;

[0035] Step II: After mixing the porous nano-scale flame retardant oxide and expanded graphite evenly, disperse them in N,N-dimethylformamide, then add 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator thereto, stir and react for 3 hours under an inert gas atmosphere at 60 °C, then rotary evaporate to remove the solvent to obtain a modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0036] In Step I, the zinc source is zinc nitrate; the silicon source is sodium silicate; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent, and sodium acetate in Step I is 0.1:1:0.2:0.1:0.1:10:3; the alcohol solvent in Step I is ethanol; the calcination temperature in Step I is 600 °C and the time is 4 h.

[0037] In Step II, the mass ratio of the porous nano-scale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator is 3:1:15:0.6:0.3:0.3:0.01; the initiator in Step II is azobisisobutyronitrile; the particle size of the expanded graphite in Step II is 100 mesh, the model is 8080200, provided by Qingdao Baixing Graphite Co., Ltd.; the inert gas in Step II is nitrogen.

[0038] A preparation method of the high-efficiency non-halogen plastic flame retardant aid includes the following steps: Mix each raw material by weight, and after ball milling and mixing evenly, obtain the high-efficiency non-halogen plastic flame retardant aid.

[0039] Example 2

[0040] A high-efficiency non-halogen plastic flame retardant aid is made of the following raw materials by weight: 37 parts of modified porous nano-scale flame retardant oxide / expanded graphite composite, 8.5 parts of organic metal hypophosphite, 10.5 parts of phosphorus-based synergist, 10.5 parts of nitrogen-based synergist, and 3.5 parts of coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0041] The coupling agent is silane coupling agent KH560; the nitrogen-based synergist is melamine cyanurate; the phosphorus-based synergist is triphenyl phosphate; the organic metal hypophosphite is aluminum hypophosphite.

[0042] The preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite includes the following steps:

[0043] Step Ⅰ: Disperse zinc source, silicon source, magnesium source, copper source, and molybdenum source in an alcohol solvent. After stirring evenly, slowly add sodium acetate, transfer the mixture to a hydrothermal reaction kettle lined with polytetrafluoroethylene, and react at 200 °C for 16 h; take out the reaction kettle, and after the reaction system cools to room temperature, wash it repeatedly with absolute ethanol and deionized water, then dry it in a vacuum drying oven at 87 °C for 13 h, and finally calcine it to obtain a porous nano-scale flame retardant oxide;

[0044] Step Ⅱ: Mix the porous nano-scale flame retardant oxide and expanded graphite evenly, disperse them in N,N-dimethylformamide, then add 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and an initiator, and stir and react at 63 °C for 3.5 h in an inert gas atmosphere, then rotary evaporate to remove the solvent to obtain a modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0045] In Step Ⅰ, the zinc source is zinc nitrate; the silicon source is silicon tetrachloride; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; in Step Ⅰ, the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent, and sodium acetate is 0.15:1:0.2:0.15:0.1:13:3; in Step Ⅰ, the alcohol solvent is ethylene glycol; in Step Ⅰ, the calcination temperature is 650 °C and the time is 4.5 h.

[0046] In Step Ⅱ, the mass ratio of the porous nano-scale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator is 3:1:17:0.6:0.3:0.35:0.015; in Step Ⅱ, the initiator is azobisisobutyronitrile; in Step Ⅱ, the particle size of the expanded graphite is 100 mesh, the model is 8080200, provided by Qingdao Baixing Graphite Co., Ltd.; in Step Ⅱ, the inert gas is helium.

[0047] A preparation method of the high-efficiency non-halogen plastic flame retardant aid includes the following steps: Mix each raw material by weight, and after ball milling and mixing evenly, obtain the high-efficiency non-halogen plastic flame retardant aid.

[0048] Example 3

[0049] An efficient non-halogen plastic flame retardant aid is made from the following raw materials by weight: 40 parts of modified porous nano-scale flame retardant oxide / expanded graphite composite, 9 parts of organic metal hypophosphite, 11 parts of phosphorus-based synergist, 11 parts of nitrogen-based synergist, and 4 parts of coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0050] The coupling agent is silane coupling agent KH570; the nitrogen-based synergist is ammonium polyphosphate; the phosphorus-based synergist is resorcinol bis(diphenyl phosphate); the organic metal hypophosphite is aluminum hypophosphite.

[0051] The preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite includes the following steps:

[0052] Step I: Disperse zinc source, silicon source, magnesium source, copper source, and molybdenum source in an alcohol solvent, stir evenly, then slowly add sodium acetate, transfer the mixture to a hydrothermal reaction kettle with a polytetrafluoroethylene liner, and react at 210 °C for 18 h; take out the reaction kettle, after the reaction system cools to room temperature, wash it repeatedly with anhydrous ethanol and deionized water, then dry it in a vacuum drying oven at 90 °C for 15 h, and finally calcine to obtain a porous nano-scale flame retardant oxide;

[0053] Step II: Mix the porous nano-scale flame retardant oxide and expanded graphite evenly, disperse them in N,N-dimethylformamide, then add 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide and initiator thereto, stir and react at 65 °C for 4 hours in an inert gas atmosphere, then rotary evaporate to remove the solvent to obtain the modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0054] In Step I, the zinc source is zinc nitrate; the silicon source is sodium silicate; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; in Step I, the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent, and sodium acetate is 0.2:1:0.2:0.2:0.1:15:3; in Step I, the alcohol solvent is n-butanol; in Step I, the calcination temperature is 700 °C and the time is 5 h.

[0055] In Step II, the mass ratio of the porous nano-scale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator is 3:1:20:0.6:0.3:0.4:0.02; the initiator in Step II is azobisisobutyronitrile; the particle size of the expanded graphite in Step II is 100 mesh, the model is 8080200, provided by Qingdao Baixing Graphite Co., Ltd.; the inert gas in Step II is neon.

[0056] A preparation method of the high-efficiency non-halogen plastic flame retardant aid includes the following steps: Mix the raw materials according to weight parts, and after ball milling and mixing evenly, obtain the high-efficiency non-halogen plastic flame retardant aid.

[0057] Example 4

[0058] A high-efficiency non-halogen plastic flame retardant aid is made of the following raw materials by weight: 43 parts of modified porous nano-scale flame retardant oxide / expanded graphite composite, 9.5 parts of organic metal hypophosphite, 11.5 parts of phosphorus-based synergist, 11.5 parts of nitrogen-based synergist, and 4.5 parts of coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0059] The coupling agent is a mixture of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 in a mass ratio of 1:2:3; the nitrogen-based synergist is a mixture of melamine, melamine cyanurate, and ammonium polyphosphate in a mass ratio of 1:3:5; the phosphorus-based synergist is a mixture of tricresyl phosphate, triphenyl phosphate, and resorcinol bis(diphenyl phosphate) in a mass ratio of 1:1:2; the organic metal hypophosphite is aluminum hypophosphite.

[0060] The preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite includes the following steps:

[0061] Step I: Disperse the zinc source, silicon source, magnesium source, copper source, and molybdenum source in an alcohol solvent, stir evenly, slowly add sodium acetate, transfer the mixture to a hydrothermal reaction kettle with a polytetrafluoroethylene liner, and react at 215°C for 19 h; take out the reaction kettle, and after the reaction system cools to room temperature, wash it repeatedly with absolute ethanol and deionized water, then dry it in a vacuum drying oven at 93°C for 18 h, and finally calcine to obtain the porous nano-scale flame retardant oxide;

[0062] Step Ⅱ: After uniformly mixing the porous nano flame retardant oxide and expanded graphite, disperse them in N,N-dimethylformamide. Then add 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide and an initiator thereto, and stir and react at 68 °C under an inert gas atmosphere for 4.5 hours. Then rotary evaporate to remove the solvent to obtain a modified porous nano flame retardant oxide / expanded graphite composite.

[0063] The zinc source in Step Ⅰ is zinc nitrate; the silicon source is sodium silicate; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent and sodium acetate in Step Ⅰ is 0.25:1:0.2:0.25:0.1:18:3; the alcohol solvent in Step Ⅰ is a mixture of ethanol, ethylene glycol and n-butanol in a mass ratio of 2:1:1; the calcination temperature in Step Ⅰ is 750 °C and the time is 5.5 h.

[0064] The mass ratio of the porous nano flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide and initiator in Step Ⅱ is 3:1:23:0.6:0.3:0.45:0.025; the initiator in Step Ⅱ is azobisisobutyronitrile; the particle size of the expanded graphite in Step Ⅱ is 100 mesh and the model is 8080200, provided by Qingdao Baixing Graphite Co., Ltd.; the inert gas in Step Ⅱ is argon.

[0065] A preparation method of the high-efficiency non-halogen plastic flame retardant aid includes the following steps: Mix each raw material by weight, and ball mill and mix uniformly to obtain the high-efficiency non-halogen plastic flame retardant aid.

[0066] Example 5

[0067] A high-efficiency non-halogen plastic flame retardant aid is made from the following raw materials by weight: 45 parts of modified porous nano flame retardant oxide / expanded graphite composite, 10 parts of organic metal hypophosphite, 12 parts of phosphorus-based synergist, 12 parts of nitrogen-based synergist, 5 parts of coupling agent; the modified porous nano flame retardant oxide / expanded graphite composite is a 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide co-modified porous nano flame retardant oxide / expanded graphite composite.

[0068] The coupling agent is silane coupling agent KH550; the nitrogen-based synergist is melamine; the phosphorus-based synergist is tricresyl phosphate; the metal organic hypophosphite is aluminum hypophosphite.

[0069] The preparation method of the modified porous nano-scale flame retardant oxide / expanded graphite composite comprises the following steps:

[0070] Step I: Dispersing a zinc source, a silicon source, a magnesium source, a copper source, and a molybdenum source in an alcohol solvent, stirring evenly, slowly adding sodium acetate, transferring the mixture to a hydrothermal reaction kettle with a polytetrafluoroethylene liner, and reacting at 220 °C for 20 h; taking out the reaction kettle, repeatedly washing with absolute ethanol and deionized water after the reaction system cools to room temperature, then drying in a vacuum drying oven at 95 °C for 20 h, and finally roasting to obtain a porous nano-scale flame retardant oxide;

[0071] Step II: After mixing the porous nano-scale flame retardant oxide and expanded graphite evenly, dispersing them in N,N-dimethylformamide, then adding 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and an initiator, stirring and reacting at 70 °C for 5 h in an inert gas atmosphere, and then rotary evaporating to remove the solvent to obtain a modified porous nano-scale flame retardant oxide / expanded graphite composite.

[0072] In Step I, the zinc source is zinc nitrate; the silicon source is silicon tetrachloride; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent, and sodium acetate in Step I is 0.3:1:0.2:0.3:0.1:20:3; the alcohol solvent in Step I is ethanol; the roasting temperature in Step I is 800 °C and the time is 6 h.

[0073] In Step II, the mass ratio of the porous nano-scale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate inner salt, 2,4,6-trivinylcyclotriboroxane, diphenyl(4-vinylphenyl)phosphine oxide, and initiator is 3:1:25:0.6:0.3:0.5:0.03; the initiator in Step II is azobisisobutyronitrile; the particle size of the expanded graphite in Step II is 100 mesh, the model is 8080200, and it is provided by Qingdao Baixing Graphite Co., Ltd.; the inert gas in Step II is argon.

[0074] A preparation method of the high-efficiency non-halogen plastic flame retardant aid comprises the following steps: mixing each raw material according to parts by weight, and ball-milling and mixing evenly to obtain the high-efficiency non-halogen plastic flame retardant aid.

[0075] Comparative Example 1

[0076] An efficient non-halogen plastic flame retardant aid and its preparation method, which is basically the same as Example 1, except that an equal amount of silicon source is used to replace the molybdenum source; an equal amount of 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate is used to replace 2,4,6-trivinylcyclotriboroxane.

[0077] Comparative Example 2

[0078] An efficient non-halogen plastic flame retardant aid and its preparation method, which is basically the same as Example 1, except that an equal amount of silicon source is used to replace the copper source; an equal amount of 2,4,6-trivinylcyclotriboroxane is used to replace 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate.

[0079] The performance tests of the efficient non-halogen plastic flame retardant aids prepared in Examples 1-5 and Comparative Examples 1-2 were carried out respectively. The test results are shown in Table 1, and the test methods are as follows: The efficient non-halogen plastic flame retardant aids prepared in each example were added to polypropylene resin (PP), and the mass ratio of the efficient non-halogen plastic flame retardant aid to PP was 10:90. The PP was the general-purpose homopolypropylene of grade T30S. The limiting oxygen index test was carried out according to GB / T 2406.2-2009 "Plastics - Determination of burning behavior by the oxygen index method - Part 2: Ambient temperature test", and the evaluation of the flame retardant grade referred to UL94-2023; the tensile property test was carried out with reference to GB / T1040.2-2006.

[0080] As can be seen from Table 1, compared with the comparative examples, the efficient non-halogen plastic flame retardant aid disclosed in the embodiments of the present invention has a better flame retardant effect and less negative impact on the mechanical properties of plastics; the combined use of molybdenum source, copper source, silicon source, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium] propane-1-sulfonate and 2,4,6-trivinylcyclotriboroxane is beneficial to improving the above properties.

[0081] Table 1

[0082] Test Items Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Tensile Strength (MPa) 39.1 39.4 39.6 40.1 40.5 38.5 38.9 Limiting Oxygen Index (%) 35.2 35.6 36.3 36.6 37.1 29.4 28.9 Flame Retardant Grade V-0 V-0 V-0 V-0 V-0 V-1 V-1

[0083] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A highly efficient non-halogen flame retardant additive for plastics, characterized in that: The invention is prepared from the following raw materials in parts by weight: 35-45 parts of a modified porous nano-scale flame retardant oxide / expanded graphite composite, 8-10 parts of an organic phosphinate metal salt, 10-12 parts of a phosphorus-based synergist, 10-12 parts of a nitrogen-based synergist, and 3-5 parts of a coupling agent; the modified porous nano-scale flame retardant oxide / expanded graphite composite is a porous nano-scale flame retardant oxide / expanded graphite composite co-modified by 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2,4,6-trivinyl cycloboroxane, and diphenyl (4-vinylphenyl) phosphine oxide.

2. The high-efficiency non-halogen flame retardant additive for plastics according to claim 1, characterized in that: The coupling agent is any one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570, or a combination of several of them; the nitrogen-based synergist is one or more of melamine, melamine cyanurate, and ammonium polyphosphate.

3. The high-efficiency non-halogen flame retardant additive for plastics according to claim 1, characterized in that: The phosphorus-based synergist is one or more of tricresyl phosphate, triphenyl phosphate, and resorcinol bis(diphenyl phosphate); and the organic phosphinate metal salt is aluminum phosphinate.

4. The high-efficiency non-halogen flame retardant additive for plastics according to claim 1, characterized in that: The preparation method of the modified porous nano-scale flame-retardant oxide / expanded graphite composite comprises the following steps: Step I: Disperse the zinc source, silicon source, magnesium source, copper source and molybdenum source in an alcohol solvent, stir evenly, slowly add sodium acetate, transfer the mixture to a polytetrafluoroethylene-lined hydrothermal reactor, and react at 195-220° C. for 15-20 hours; take out the reactor, and after the reaction system is cooled to room temperature, repeatedly wash it with anhydrous ethanol and deionized water, then dry it in a vacuum drying oven at 85-95° C. for 10-20 hours, and finally calcine to obtain a porous nano-scale flame retardant oxide; Step II: After the porous nano-scale flame retardant oxide and expanded graphite are uniformly mixed, they are dispersed in N,N-dimethylformamide, and then 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2,4,6-trivinylcycloboroxine, diphenyl (4-vinylphenyl) phosphine oxide and initiator are added thereto, and the reaction is stirred at 60-70° C. in an inert gas atmosphere for 3-5 hours, and then the solvent is removed by rotary evaporation to obtain a modified porous nano-scale flame retardant oxide / expanded graphite composite.

5. The high-efficiency non-halogen flame retardant additive for plastics according to claim 4, characterized in that: The zinc source in step I is zinc nitrate; the silicon source is at least one of sodium silicate and silicon tetrachloride; the magnesium source is magnesium nitrate; the copper source is copper chloride; the molybdenum source is molybdenum chloride; the mass ratio of the zinc source, silicon source, magnesium source, copper source, molybdenum source, alcohol solvent and sodium acetate in step I is (0.1-0.3):1:0.2:(0.1-0.3):0.1:(10-20):

3.

6. The high-efficiency non-halogen flame retardant additive for plastics according to claim 4, characterized in that: The alcohol solvent in step I is at least one of ethanol, ethylene glycol and n-butanol; the calcination temperature in step I is 600-800° C. and the calcination time is 4-6 hours.

7. The high-efficiency non-halogen flame retardant additive for plastics according to claim 4, characterized in that: The mass ratio of the porous nanoscale flame retardant oxide, expanded graphite, N,N-dimethylformamide, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, 2,4,6-trivinyl cycloboroxine, diphenyl (4-vinylphenyl) phosphine oxide, and initiator in step II is 3:1:(15-25):0.6:0.3:(0.3-0.5):(0.01-0.03).

8. The high-efficiency non-halogen flame retardant additive for plastics according to claim 4, characterized in that: The initiator in step II is azobisisobutyronitrile; the particle size of the expanded graphite in step II is 100 mesh, and the model is 8080200.

9. The high-efficiency non-halogen flame retardant additive for plastics according to claim 4, characterized in that: The inert gas in step II is any one of nitrogen, helium, neon and argon.

10. A method for preparing a high-efficiency non-halogen flame retardant additive for plastics according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: mixing the raw materials according to weight parts, and evenly mixing them by ball milling to obtain a high-efficiency non-halogen flame retardant additive for plastics.