Water-based flame-retardant latex and preparation method thereof

Abstract

The invention relates to the field of organic high-molecular polymers, and particularly discloses water-based flame-retardant latex and a preparation method thereof. The water-based flame-retardant latex is prepared from the following raw materials in parts by weight: 120 parts of water, 30 to 70 parts of butadiene, 5 to 20 parts of functional monomer, 0.5 to 3 parts of compound emulsifier, 0.3 to 1.5 parts of initiator, 0.3 to 0.8 part of terminator and 0.1 to 0.3 part of antioxidant, the functional monomer is prepared from acrylic ester, N-phenyl maleimide, triallyloxy methyl phosphine oxide and N, N-dimethyl propionamide. The water-based flame-retardant latex disclosed by the invention is relatively narrow in particle size distribution, relatively good in chemical stability and mechanical stability and relatively high in flame retardant property, and has an extremely high application prospect.

Description

Technical Field

[0001] The present invention relates to the field of organic high molecular polymers, and more specifically, to a water-based flame retardant latex and a preparation method thereof. Background Art

[0002] Water-based latex is a colloidal emulsion formed by dispersing polymer latex particles in water as a dispersion medium. Compared with solvent-based latex, water-based latex contains no or only a small amount of organic solvents, and almost no harmful volatile substances are released during use. It is more friendly to the environment and human health, and has obvious advantages such as environmental protection, non-toxicity, and easy operation. It is widely used in the fields of construction, coatings, adhesives, textiles, papermaking, etc.

[0003] As the application scope of water-based latex becomes wider and wider, people pay more and more attention to the flame retardant modification of water-based latex. At present, adding flame retardants to water-based latex is a common means to obtain excellent flame retardant properties. Flame retardants can be divided into halogen-containing flame retardants and phosphorus-containing flame retardants according to different flame retardant elements. Among them, phosphorus-containing flame retardants are the most widely used green flame retardants at this stage because they have the characteristics of exerting flame retardant effects in both gas phase and condensed phase, and will not release toxic and harmful gases during thermal decomposition.

[0004] However, at present, the phosphorus-containing flame retardants added to water-based latex are mostly additive flame retardants, such as triethyl phosphate, diethyl ethylphosphonate, etc., which will have a great influence on the crosslinking density of the water-based latex during the preparation process of the water-based latex, thereby reducing the various properties of the water-based latex. Summary of the invention

[0005] In order to solve the above technical problems, the present application provides an aqueous flame retardant latex and a preparation method thereof.

[0006] In the first aspect, the present application provides a water-based flame retardant latex, which adopts the following technical solution: A water-based flame retardant latex, the raw materials used include the following components in parts by weight: 120 parts water; Butadiene 30-70 parts; 30-50 parts of styrene; 5-20 parts of functional monomer; 0.5-3 parts of compound emulsifier; Initiator 0.3-1.5 parts; Terminator 0.3-0.8 parts; Antioxidant 0.1-0.3 parts; The functional monomers include acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide.

[0007] By adopting the above technical scheme, the present application adopts a mixture of acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide as functional monomers to participate in the polymerization reaction process, which can fully utilize the synergistic effect between these four reaction monomers to improve the crosslinking density of the water-based flame retardant latex, so that the water-based flame retardant latex has both high flame retardant properties and high mechanical properties.

[0008] Among them, the structural formula is The N-phenylmaleimide not only increases the crosslinking density of the water-based flame retardant latex, but also provides maleimide groups for the water-based flame retardant latex, and the maleimide groups can further enhance the mechanical properties and thermal stability of the water-based flame retardant latex.

[0009] Moreover, compared with the additive phosphorus-containing flame retardant, the structural formula is Triallyloxymethylphosphine oxide can directly participate in the polymerization reaction of water-based flame retardant latex, thus increasing the crosslinking density of the water-based flame retardant latex, improving the mechanical properties, and also enabling it to obtain a long-lasting and efficient flame retardant ability.

[0010] In addition to participating in the polymerization reaction as a functional monomer, N,N-dimethylpropionamide also plays a role in dissolving N-phenylmaleimide. At the same time, N,N-dimethylpropionamide can also improve the stability of the water-based flame retardant latex by increasing the hydrophilicity of the system and reducing the amount of compound emulsifier in the system.

[0011] In summary, by introducing N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide, the present application can make the prepared water-based flame retardant latex have higher mechanical properties, better chemical stability and mechanical stability, stronger flame retardant properties, and has extremely high application prospects.

[0012] Preferably, the weight ratio of the acrylic acid ester, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide is (30-50):(10-15):(10-15):(30-40).

[0013] Through the above technical scheme, the present application optimizes the ratio between acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N, N-dimethylpropionamide, and gives full play to the synergistic effect between the components, so that the water-based flame retardant latex prepared has good mechanical properties, chemical stability, mechanical stability and flame retardant properties. And it has been proved by experiments that when the weight ratio of acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N, N-dimethylpropionamide is 50:10:10:30, the water-based flame retardant latex prepared has better water resistance and peel strength.

[0014] Preferably, the acrylic acid ester comprises one or more of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate. Preferably, the compound emulsifier includes at least two of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane.

[0015] Preferably, the compound emulsifier comprises sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane in a weight ratio of (30-50):(20-30):(30-40).

[0016] By adopting the above technical scheme, the present application adopts a certain ratio of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate (CAS No. 68603-42-9) and hydroxyl-terminated polydimethylsiloxane (CAS No. 70131-67-8) mixed as a compound emulsifier, which can give full play to the synergistic effect between the three, thereby effectively controlling the generation and growth process of latex particles, obtaining a latex with a more uniform particle size and a narrower distribution, improving the mechanical stability and chemical stability of the water-based flame retardant latex, and enhancing the product quality. In addition, the alkyl alcohol amide phosphate can also increase the phosphorus content of the water-based flame retardant latex, thereby exerting a synergistic effect with triallyloxymethylphosphine oxide, and further improving the flame retardant properties of the water-based flame retardant latex.

[0017] Preferably, the initiator is one of ammonium persulfate, sodium persulfate and potassium persulfate.

[0018] Preferably, the terminator is one of sodium thiocarbamide, acetone thiosemicarbazone, N,N-diethylhydroxylamine, triethylamine, and melamine.

[0019] Preferably, the antioxidant is one of tridecyl phosphite, tridodecyl phosphite, tritridecyl phosphite, pentaerythritol didecyl diphosphite and dioctadecyl diphosphite.

[0020] In a second aspect, the present application provides a method for preparing a water-based flame retardant latex, which adopts the following technical solution: A method for preparing an aqueous flame retardant latex comprises the following steps: S1. Seed emulsion synthesis 36 parts by weight of water, 6-14 parts by weight of butadiene, 6-10 parts by weight of styrene, 0.15-0.9 parts by weight of a composite emulsifier and 0.12-0.6 parts by weight of an initiator are mixed, and reacted at a temperature of 60-80° C. for 1-1.5 hours, and then heated to 85-90° C. and continued to react for 2-2.5 hours to obtain emulsion A; S2. Pre-emulsification Emulsifying 5-20 parts by weight of a functional monomer, 0.15-0.9 parts by weight of a compound emulsifier, 24-40 parts by weight of styrene and 48 parts by weight of water at a rotation speed of 1000-1500 r / min to obtain an emulsion B; S3. Polymerization Mix all emulsion A, 36 parts by weight of water and 0.2-1.2 parts by weight of compound emulsifier, heat to 80-95°C, then add 24-56 parts by weight of butadiene, all emulsion B and 0.18-0.9 parts by weight of initiator, keep warm for 1-2 hours, cool to 60-65°C after the reaction, and add 0.3-0.8 parts by weight of terminator; S4. Post-processing At a temperature below 40° C., 0.1-0.3 parts of an antioxidant is added to the product obtained in step S3 , and the mixture is mixed and then discharged to obtain a water-based flame retardant latex.

[0021] By adopting the above technical solution, the present application effectively controls the generation and growth process of latex particles, and the obtained water-based flame-retardant latex has a more uniform particle size and a narrower distribution, better chemical stability and mechanical stability, and stronger flame retardant performance.

[0022] In summary, this application has the following beneficial technical effects: 1. The water-based flame retardant latex of the present application has a narrow particle size distribution, good chemical stability and mechanical stability, strong flame retardant performance, and has extremely high application prospects; 2. The preparation method of the water-based flame-retardant latex of the present application has simple steps, is easy to operate, and is suitable for large-scale industrial production. DETAILED DESCRIPTION

[0023] The present application is further described in detail below using examples and comparative examples.

[0024] Since there is no significant difference in the effect of initiating the reaction among ammonium persulfate, sodium persulfate and potassium persulfate as initiators, sodium persulfate is used as an example for illustration in the specific embodiments of the present application.

[0025] Since there is no significant difference in the effect of terminating the reaction among sodium thiocarbamate, acetone thiosemicarbazone, N,N-diethylhydroxylamine, triethylamine and melamine as terminators, melamine is used as an example for illustration in the specific implementation of the present application.

[0026] Since there is no significant difference in the antioxidant effect of tridecyl phosphite, tridodecyl phosphite, tritridecyl phosphite, pentaerythritol didecyl diphosphite and dioctadecyl diphosphite as antioxidants, in the specific embodiment of the present application, tridecyl phosphite (antioxidant TDP, CAS No. 25448-25-3) is taken as an example for description.

[0027] Unless otherwise specified, the raw materials used in this application are all commercially available products, including: Triallyloxymethylphosphine oxide is made by our company. Its preparation method can refer to our company's invention patent with announcement number CN116284122A. Its structural formula is

[0028] Example 1 A method for preparing an aqueous flame retardant latex comprises the following steps: S1. Seed emulsion synthesis 36 kg of deionized water, 6 kg of butadiene, 10 kg of styrene, 0.9 kg of a composite emulsifier (0.45 kg of sodium dodecylbenzene sulfonate, 0.45 kg of hydroxyl-terminated polydimethylsiloxane) and 0.12 kg of sodium persulfate were mixed, reacted at 60° C. for 1.5 h, and then heated to 85° C. for further reaction for 2.5 h to obtain emulsion A; S2. Pre-emulsification 5 kg of functional monomer, 0.9 kg of composite emulsifier (0.45 kg of sodium dodecylbenzene sulfonate, 0.45 kg of hydroxyl-terminated polydimethylsiloxane), 40 kg of styrene and 48 kg of water were emulsified at a speed of 1000 r / min to obtain emulsion B; S3. Polymerization Mix all emulsion A, 36 kg water and 1.2 kg composite emulsifier (0.6 kg sodium dodecylbenzene sulfonate, 0.6 kg hydroxyl-terminated polydimethylsiloxane) and heat to 80°C, then add 24 kg butadiene, all emulsion B and 0.18 kg sodium persulfate to react for 2 hours. After the reaction, cool to 60°C and add 0.8 kg melamine; S4. Post-processing At a temperature below 40° C., 0.1 kg of tridecyl phosphite was added to the product obtained in step S3, and the mixture was mixed and then discharged to obtain an aqueous flame retardant latex.

[0029] Among them, the functional monomers include methyl acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide in a weight ratio of 50:10:10:30, specifically: 2.5 kg of methyl acrylate, 0.5 kg of N-phenylmaleimide, 0.5 kg of triallyloxymethylphosphine oxide, and 1.5 kg of N,N-dimethylpropionamide.

[0030] Example 2 A method for preparing an aqueous flame retardant latex comprises the following steps: S1. Seed emulsion synthesis 36 kg of deionized water, 6 kg of butadiene, 10 kg of styrene, 0.9 kg of a composite emulsifier (0.45 kg of sodium dodecylbenzene sulfonate, 0.45 kg of hydroxyl-terminated polydimethylsiloxane) and 0.12 kg of sodium persulfate were mixed, reacted at 60° C. for 1.5 h, and then heated to 85° C. for further reaction for 2.5 h to obtain emulsion A; S2. Pre-emulsification 5 kg of functional monomer, 0.9 kg of composite emulsifier (0.45 kg of sodium dodecylbenzene sulfonate, 0.45 kg of hydroxyl-terminated polydimethylsiloxane), 40 kg of styrene and 48 kg of water were emulsified at a speed of 1000 r / min to obtain emulsion B; S3. Polymerization Mix all emulsion A, 36 kg water and 1.2 kg composite emulsifier (0.6 kg sodium dodecylbenzene sulfonate, 0.6 kg hydroxyl-terminated polydimethylsiloxane) and heat to 80°C, then add 24 kg butadiene, all emulsion B and 0.18 kg sodium persulfate to react for 2 hours. After the reaction, cool to 60°C and add 0.8 kg melamine; S4. Post-processing At a temperature below 40° C., 0.1 kg of tridecyl phosphite was added to the product obtained in step S3, and the mixture was mixed and then discharged to obtain an aqueous flame retardant latex.

[0031] Among them, the functional monomers include methyl acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide in a weight ratio of 30:15:15:40, specifically: 1.5kg of methyl acrylate, 0.75kg of N-phenylmaleimide, 0.75kg of triallyloxymethylphosphine oxide and 2kg of N,N-dimethylpropionamide.

[0032] Example 3 A method for preparing an aqueous flame retardant latex comprises the following steps: S1. Seed emulsion synthesis 36 kg of deionized water, 14 kg of butadiene, 6 kg of styrene, 0.15 kg of a composite emulsifier (0.075 kg of sodium dodecylbenzene sulfonate, 0.075 kg of hydroxyl-terminated polydimethylsiloxane) and 0.6 kg of sodium persulfate were mixed, reacted at 80° C. for 1 h, then heated to 90° C. for further reaction for 2 h, to obtain emulsion A; S2. Pre-emulsification 20 kg of functional monomer, 0.15 kg of composite emulsifier (0.075 kg of sodium dodecylbenzene sulfonate, 0.075 kg of hydroxyl-terminated polydimethylsiloxane), 24 kg of styrene and 48 kg of water were emulsified at a speed of 1500 r / min to obtain emulsion B; S3. Polymerization Mix all emulsion A, 36 kg water and 0.2 kg composite emulsifier (0.1 kg sodium dodecylbenzene sulfonate, 0.1 kg hydroxyl-terminated polydimethylsiloxane) and heat to 95°C, then add 56 kg butadiene, all emulsion B and 0.9 kg sodium persulfate and keep warm for 1 hour. After the reaction, cool to 65°C and add 0.3 kg melamine; S4. Post-processing At a temperature below 40° C., 0.3 kg of tridecyl phosphite was added to the product obtained in step S3, and the mixture was mixed and then discharged to obtain an aqueous flame retardant latex.

[0033] Among them, the functional monomers include methyl acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide in a weight ratio of 50:10:10:30, specifically: 10kg of methyl acrylate, 2kg of N-phenylmaleimide, 2kg of triallyloxymethylphosphine oxide, and 6kg of N,N-dimethylpropionamide.

[0034] Example 4 A method for preparing an aqueous flame retardant latex comprises the following steps: S1. Seed emulsion synthesis 36 kg of deionized water, 14 kg of butadiene, 6 kg of styrene, 0.15 kg of a composite emulsifier (0.075 kg of sodium dodecylbenzene sulfonate, 0.075 kg of hydroxyl-terminated polydimethylsiloxane) and 0.6 kg of sodium persulfate were mixed, reacted at 80° C. for 1 h, then heated to 90° C. for further reaction for 2 h, to obtain emulsion A; S2. Pre-emulsification 20 kg of functional monomer, 0.15 kg of composite emulsifier (0.075 kg of sodium dodecylbenzene sulfonate, 0.075 kg of hydroxyl-terminated polydimethylsiloxane), 24 kg of styrene and 48 kg of water were emulsified at a speed of 1500 r / min to obtain emulsion B; S3. Polymerization Mix all emulsion A, 36 kg water and 0.2 kg composite emulsifier (0.1 kg sodium dodecylbenzene sulfonate, 0.1 kg hydroxyl-terminated polydimethylsiloxane) and heat to 95°C, then add 56 kg butadiene, all emulsion B and 0.9 kg sodium persulfate and keep warm for 1 hour. After the reaction, cool to 65°C and add 0.3 kg melamine; S4. Post-processing At a temperature below 40° C., 0.3 kg of tridecyl phosphite was added to the product obtained in step S3, and the mixture was mixed and then discharged to obtain an aqueous flame retardant latex.

[0035] Among them, the functional monomers include butyl acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide in a weight ratio of 30:15:15:40, specifically: 6kg of butyl acrylate, 3kg of N-phenylmaleimide, 3kg of triallyloxymethylphosphine oxide, and 8kg of N,N-dimethylpropionamide.

[0036] Example 5 A method for preparing a water-based flame retardant latex, which is different from Example 4 in that: the compound emulsifiers in steps S1, S2, and S3 are all compound emulsifiers mixed with sodium dodecylbenzene sulfonate and alkyl alcohol amide phosphate, and the rest are the same as Example 4. Among them, the weight ratio of sodium dodecylbenzene sulfonate to alkyl alcohol amide phosphate is 1:1, specifically: in step S1, 0.075 kg of sodium dodecylbenzene sulfonate and 0.075 kg of alkyl alcohol amide phosphate; in step S2, 0.075 kg of sodium dodecylbenzene sulfonate and 0.075 kg of alkyl alcohol amide phosphate; in step S3, 0.1 kg of sodium dodecylbenzene sulfonate and 0.1 kg of alkyl alcohol amide phosphate.

[0037] Example 6 A method for preparing a water-based flame retardant latex, which is different from Example 4 in that: the compound emulsifiers in steps S1, S2, and S3 are all compound emulsifiers mixed with alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane, and the rest are the same as Example 4. Among them, the weight ratio of alkyl alcohol amide phosphate to hydroxyl-terminated polydimethylsiloxane is 1:1, specifically: in step S1, 0.075 kg of alkyl alcohol amide phosphate and 0.075 kg of hydroxyl-terminated polydimethylsiloxane; in step S2, 0.075 kg of alkyl alcohol amide phosphate and 0.075 kg of hydroxyl-terminated polydimethylsiloxane; in step S3, 0.1 kg of alkyl alcohol amide phosphate and 0.1 kg of hydroxyl-terminated polydimethylsiloxane.

[0038] Example 7 A method for preparing a water-based flame retardant latex, which is different from that of Example 4 in that the compound emulsifiers in steps S1, S2 and S3 are all compound emulsifiers mixed with sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane, and the rest are the same as those in Example 4. The weight ratio of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane is 50:20:30, specifically: in step S1, 0.075kg of sodium dodecylbenzene sulfonate, 0.03kg of alkyl alcohol amide phosphate and 0.045kg of hydroxyl-terminated polydimethylsiloxane; in step S2, 0.075kg of sodium dodecylbenzene sulfonate, 0.03kg of alkyl alcohol amide phosphate and 0.045kg of hydroxyl-terminated polydimethylsiloxane; in step S3, 0.1kg of sodium dodecylbenzene sulfonate, 0.04kg of alkyl alcohol amide phosphate and 0.06kg of hydroxyl-terminated polydimethylsiloxane.

[0039] Example 8 A method for preparing a water-based flame retardant latex, which is different from that of Example 4 in that the compound emulsifiers in steps S1, S2 and S3 are all compound emulsifiers mixed with sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane, and the rest are the same as those in Example 4. Among them, the weight ratio of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane is 30:30:40, specifically: in step S1, 0.045kg of sodium dodecylbenzene sulfonate, 0.045kg of alkyl alcohol amide phosphate and 0.06kg of hydroxyl-terminated polydimethylsiloxane; in step S2, 0.045kg of sodium dodecylbenzene sulfonate, 0.045kg of alkyl alcohol amide phosphate and 0.06kg of hydroxyl-terminated polydimethylsiloxane; in step S3, 0.06kg of sodium dodecylbenzene sulfonate, 0.06kg of alkyl alcohol amide phosphate and 0.08kg of hydroxyl-terminated polydimethylsiloxane.

[0040] Comparative Example 1 The difference from Example 4 is that in step S2, the functional monomers include methyl acrylate and butyl acrylate in a ratio of 1:1, specifically: 10 kg of methyl acrylate and 10 kg of butyl acrylate, and the rest are the same as Example 4.

[0041] Comparative Example 2 The difference from Example 4 is that in step S2, the functional monomers include butyl acrylate and N,N-dimethylpropionamide in a ratio of 7:3, specifically: 14 kg of butyl acrylate and 6 kg of N,N-dimethylpropionamide, and the rest are the same as Example 4.

[0042] Comparative Example 3 The difference from Example 4 is that in step S2, the functional monomers include butyl acrylate and triallyloxymethyl phosphine oxide in a ratio of 7:3, specifically: 14 kg of butyl acrylate and 6 kg of triallyloxymethyl phosphine oxide, and the rest are the same as Example 4.

[0043] Comparative Example 4 The difference from Example 4 is that in step S2, the functional monomers include butyl acrylate, N-phenylmaleimide and N,N-dimethylpropionamide in a ratio of 4:3:3, specifically: 8 kg of butyl acrylate, 6 kg of N-phenylmaleimide, and 6 kg of N,N-dimethylpropionamide, and the rest are the same as Example 4.

[0044] Comparative Example 5 The difference from Example 4 is that in step S2, the functional monomers include butyl acrylate, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide in a ratio of 4:3:3, specifically: 8 kg of butyl acrylate, 6 kg of triallyloxymethylphosphine oxide, and 6 kg of N,N-dimethylpropionamide, and the rest are the same as Example 4.

[0045] Performance Testing 1. Referring to GB / T 2406.2-2009 standard, the above embodiments and comparative examples were made into samples with a shape of 100 mm×10 mm×4 mm and then tested for limiting oxygen index (LOI, %). The test results are shown in Table 1. 2. With reference to GB / T 26843-2011 carpet backing peel strength determination standard, a microcomputer-controlled electronic universal testing machine was used to test the peel strength (N) of the water-based flame retardant latex prepared in the above embodiments and comparative examples. The test results are shown in Table 1. 3. With reference to SH / T 1151-1992 (2005) standard, the mechanical stability (%) of the water-based flame retardant latex prepared in the above embodiments and comparative examples was tested. The test results are shown in Table 1. 4. Referring to SH / T 1608-1995 standard, the chemical stability (%) of the water-based flame retardant latex prepared in the above examples and comparative examples was tested. The test results are shown in Table 1; 5. The particle size of the water-based flame retardant latex prepared in the above examples and comparative examples was measured using a Malvern 3000 laser particle size analyzer, and the number average particle size (d.nm) was recorded in Table 1.

[0046] Table 1 Performance test results Data Analysis: As can be seen from Table 1, the limiting oxygen index of the water-based flame retardant latex prepared in the present application is 35.8-37.9%, the peel strength is 42.8-45.7N, the mechanical stability is 0.039-0.068%, the chemical stability has passed the test, and the number average particle size is 423.6-567.7nm. The test data show that the water-based flame retardant latex prepared in the present application has a narrow particle size distribution, good chemical stability and mechanical stability, and has good flame retardant properties and mechanical properties, and has a very high application prospect.

[0047] Among them, by comparing Examples 1-2 and 3-4, it can be seen that when the weight ratio of acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide is 50:10:10:30, the obtained water-based flame retardant latex has better water resistance and peel strength.

[0048] By comparing the test data of Examples 4-8, it can be seen that the particle size distribution of the water-based flame retardant latex prepared in Examples 7-8 is narrower, the mechanical stability is higher, and the flame retardant properties and mechanical properties are stronger. The test data show that Examples 7-8 use a certain ratio of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane to mix and match, which can give full play to the synergistic effect between the three, thereby effectively controlling the generation and growth process of latex particles, obtaining a latex with a more uniform particle size and a narrower distribution, improving the mechanical stability and chemical stability of the water-based flame retardant latex, and further improving the flame retardant properties of the water-based flame retardant latex.

[0049] The limiting oxygen index of the water-based flame retardant latex obtained in Comparative Examples 1-5 is 17.0-34.0%, the peel strength is 34.3-40.6N, the mechanical stability is 0.081-0.125%, the chemical stability is tested, and the number average particle size is 608.7-786.6nm. The test data show that the performance of the water-based flame retardant latex obtained in Comparative Examples 1-5 is worse than that of Example 4, which shows that the present application can make the particle size of the latex more uniform and narrowly distributed by introducing N-phenylmaleimide, triallyloxymethylphosphine oxide and N, N-dimethylpropionamide into the functional monomer, which significantly improves the mechanical properties, mechanical stability and flame retardant properties of the water-based flame retardant latex. And from the data comparison of Comparative Examples 1-5 and Example 4, it can be seen that N-phenylmaleimide, triallyloxymethylphosphine oxide and N, N-dimethylpropionamide need to be used simultaneously to give full play to the synergistic effect between each other.

[0050] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A water-based flame retardant latex, characterized in that: The raw materials used include the following components in parts by weight: 120 parts water; Butadiene 30-70 parts; 30-50 parts of styrene; 5-20 parts of functional monomer; 0.5-3 parts of compound emulsifier; Initiator 0.3-1.5 parts; Terminator 0.3-0.8 parts; Antioxidant 0.1-0.3 parts; The functional monomers include acrylate, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide.

2. The water-based flame retardant latex according to claim 1, characterized in that: The weight ratio of the acrylic acid ester, N-phenylmaleimide, triallyloxymethylphosphine oxide and N,N-dimethylpropionamide is (30-50): (10-15): (10-15): (30-40).

3. The water-based flame retardant latex according to claim 1, characterized in that: The acrylic acid ester includes one or more of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, hydroxyethyl acrylate and hydroxyethyl methacrylate.

4. The water-based flame retardant latex according to claim 1, characterized in that: The compound emulsifier comprises at least two of sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane.

5. The water-based flame retardant latex according to claim 4, characterized in that: The compound emulsifier comprises sodium dodecylbenzene sulfonate, alkyl alcohol amide phosphate and hydroxyl-terminated polydimethylsiloxane in a weight ratio of (30-50): (20-30): (30-40).

6. The water-based flame retardant latex according to claim 1, characterized in that: The initiator is one of ammonium persulfate, sodium persulfate and potassium persulfate.

7. The water-based flame retardant latex according to claim 1, characterized in that: The terminator is one of sodium thiamethoxam, acetone thiosemicarbazone, N,N-diethylhydroxylamine, triethylamine and melamine.

8. The water-based flame retardant latex according to claim 1, characterized in that: The antioxidant is one of tridecyl phosphite, tridodecyl phosphite, tritridecyl phosphite, pentaerythritol didecyl diphosphite and dioctadecyl diphosphite.

9. A method for preparing the water-based flame retardant latex according to claim 1, characterized in that: The following steps are involved: S1. Seed emulsion synthesis 36 parts by weight of water, 6-14 parts by weight of butadiene, 6-10 parts by weight of styrene, 0.15-0.9 parts by weight of a composite emulsifier and 0.12-0.6 parts by weight of an initiator are mixed, and reacted at a temperature of 60-80° C. for 1-1.5 hours, and then heated to 85-90° C. and continued to react for 2-2.5 hours to obtain emulsion A; S2. Pre-emulsification Emulsifying 5-20 parts by weight of a functional monomer, 0.15-0.9 parts by weight of a compound emulsifier, 24-40 parts by weight of styrene and 48 parts by weight of water at a rotation speed of 1000-1500 r / min to obtain an emulsion B; S3. Polymerization Mix all emulsion A, 36 parts by weight of water and 0.2-1.2 parts by weight of compound emulsifier, heat to 80-95°C, then add 24-56 parts by weight of butadiene, all emulsion B and 0.18-0.9 parts by weight of initiator, keep warm for 1-2 hours, cool to 60-65°C after the reaction, and add 0.3-0.8 parts by weight of terminator; S4. Post-processing At a temperature below 40° C., 0.1-0.3 parts of an antioxidant is added to the product obtained in step S3 , and the mixture is mixed and then discharged to obtain a water-based flame retardant latex.

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