Preparation method of intrinsically flame-retardant high-elasticity styrene-acrylic emulsion

Abstract

The application discloses a preparation method of an intrinsically flame-retardant high-elasticity styrene-acrylic emulsion, which comprises the following steps: preparing a phosphorus-nitrogen integrated functional compound by using glycine, polyformaldehyde and dimethyl phosphite as raw materials; performing acyl chloride modification on the phosphorus-nitrogen integrated functional compound by using sulfoxide chloride; preparing a high-flexibility flame-retardant monomer by reacting the acyl chloride modified phosphorus-nitrogen integrated functional compound with a phenolic hydroxyl cashew phenol; and finally preparing the flame-retardant high-elasticity styrene-acrylic emulsion by reacting the high-flexibility flame-retardant monomer, styrene, butyl acrylate and acrylic acid in a cationic etherified starch aqueous solution. The emulsion has the multiple advantages of flame retardation, high elasticity, soap-free, water resistance and the like, is green and environment-friendly, low in cost, and has a wide application value.

Description

Technical Field

[0001] This invention relates to a method for preparing an inherently flame-retardant, highly elastic styrene-acrylic emulsion. Background Technology

[0002] Styrene-acrylic emulsions are emulsions prepared by polymerization under specific conditions, primarily using styrene and acrylate monomers, with the addition of small amounts of other compounds and additives. Their low cost makes them widely used in coatings and related fields. Traditional emulsion polymerization methods, due to the large amount of emulsifier added, lead to a decline in emulsion quality, resulting in problems such as yellowing and foul odor. One solution is to reduce the amount of emulsifier used by employing soap-free emulsion polymerization methods. Starch, as a widely available, inexpensive, green, environmentally friendly, and renewable resource, is a good alternative to traditional emulsifiers. By grafting cationic starch onto styrene-acrylic emulsions, emulsion products with good water resistance and film-forming properties can be prepared.

[0003] On the other hand, with social development and increased emphasis on safety, there is a growing demand for styrene-acrylic emulsions in areas such as flame retardant fabrics. Higher elasticity and better flame retardant properties are hot topics in the industry. Cashew nut shell oil, an agricultural byproduct distilled from natural cashew nut shell oil, has advantages such as wide availability, low price, environmental friendliness, and renewability. Its unique long-chain structure provides excellent toughness, while the rigid benzene rings offer a balance of rigidity and flexibility, making it a focus of attention in recent years.

[0004] Flame-retardant, high-elasticity cashew nut shell powder (CPFP) can be prepared by modifying its phenolic hydroxyl groups. This CPFP is then introduced into a styrene-acrylic emulsion system to produce a highly elastic, inherently flame-retardant styrene-acrylic emulsion. This invention first etherifies starch to make it cationic starch, which is then used in the flame-retardant modified cashew nut shell powder, styrene, acrylate, and acrylic acid graft emulsion polymerization to prepare a styrene-acrylic emulsion with high flame retardancy, high water resistance, and high elasticity. The preparation of this inherently flame-retardant, high-elasticity styrene-acrylic emulsion provides a new approach to address this market demand. Summary of the Invention

[0005] The purpose of this invention is to provide an inherently flame-retardant, highly elastic styrene-acrylic emulsion.

[0006] To achieve the above objectives, the preparation method of the inherently flame-retardant high-elasticity styrene-acrylic emulsion of the present invention includes the following steps: first, a phosphorus-nitrogen integrated functional compound is prepared using glycine, paraformaldehyde, and dimethyl phosphite as raw materials; then, the phosphorus-nitrogen integrated functional compound is modified by acyl chloride; next, the acyl-modified phosphorus-nitrogen integrated functional compound is reacted with phenolic hydroxy cashew phenol to obtain a highly flexible flame-retardant monomer; finally, the highly flexible flame-retardant monomer, styrene, butyl acrylate, and acrylic acid are reacted in a cationic etherified starch aqueous solution to obtain the inherently flame-retardant high-elasticity styrene-acrylic emulsion.

[0007] The preparation method of the inherently flame-retardant, highly elastic styrene-acrylic emulsion of the present invention includes the following specific steps:

[0008] (1) Mix paraformaldehyde, glycine and tetrahydrofuran and heat to 60-70℃, then add dimethyl phosphite dropwise. After the addition is complete, continue to keep the temperature and react until the reaction is complete. After the reaction is complete, remove the solvent tetrahydrofuran and obtain a light yellow viscous liquid, which is the phosphorus-nitrogen integrated functional compound. The code name of this phosphorus-nitrogen integrated functional compound is HOOC-NP2.

[0009] (2) Dissolve the phosphorus-nitrogen integrated functional compound in a solvent and add a catalyst. Add thionyl chloride dropwise at a temperature of 0-15℃. After the dropwise addition is complete, raise the temperature to 70-80℃ and continue to keep the reaction at this temperature until the reaction is complete to obtain a product solution. Add saturated saline and sodium hydroxide solution to the product solution to wash the product solution, and then separate the inorganic phase. Add anhydrous sodium sulfate to the organic phase for drying. After drying, separate the solid and liquid phases. Remove the solvent from the liquid product obtained from the solid-liquid separation to obtain the acyl chloride modified flame retardant functional monomer. The code of the acyl chloride modified flame retardant functional monomer is ClOC-NP2. The mass concentration of the sodium hydroxide solution is 5%. After washing, the organic phase and inorganic phase are generally separated by static layering. Then the inorganic phase is separated and the organic phase is retained.

[0010] (3) Mix phenolic hydroxy cashew phenol (CAS: 501-26-8) with a solvent and add triethylamine. Dissolve the acyl chloride-modified flame retardant functional monomer in the solvent to prepare a flame retardant functional monomer solution. Add the flame retardant functional monomer solution dropwise at -5℃. After the addition is complete, carry out a low-temperature reaction at -10-0℃, and then continue the reaction at 5-15℃ until the reaction is complete. After the reaction is complete, filter to obtain a liquid crude product. Wash the liquid crude product sequentially with acetic acid solution, NaOH solution, and saturated saline solution, and then dry it with anhydrous sodium sulfate. After drying, separate the solid and liquid to obtain a product solution. Remove the solvent from the product solution to obtain a light yellow viscous liquid, which is the high-flexibility flame retardant monomer. The mass concentrations of acetic acid solution and NaOH solution are 2% and 10%, respectively. The washing and drying operations are as follows: Add acetic acid solution to the liquid crude product for washing. After washing, let it stand and separate into layers. Separate the inorganic phase and retain the organic phase. Then add NaOH to the organic phase. The solution is washed, and after washing, it is allowed to stand and separate into layers, separating the inorganic phase and retaining the organic phase; then saturated saline solution is added to the organic phase for washing, and after washing, it is allowed to stand and separate into layers, separating the inorganic phase and retaining the organic phase; finally, anhydrous sodium sulfate is added to the organic phase for drying, and after drying, solid-liquid separation is performed.

[0011] (4) Mix starch and water, heat in a water bath to 40-60℃, add ammonia to adjust the pH to 8.5-10, add etherifying agent, keep warm and stir for 1-2 hours, add hydrogen peroxide, keep warm for 30-60 minutes, then heat to 70-90℃ and continue the reaction for 0.3-1 hours. After the reaction is complete, a transparent cationic etherified starch aqueous solution is obtained.

[0012] (5) Heat the cationic etherified starch aqueous solution to 60-85℃ in a water bath, add hydrogen peroxide and potassium persulfate aqueous solution dropwise, and keep the dropwise addition. Add high flexibility flame retardant monomer and styrene, and carry out a first polymerization reaction for 0.5-2 h. Then add butyl acrylate and acrylic acid, and carry out a second polymerization reaction for 0.5-2 h. At the same time as the second polymerization reaction is completed, add hydrogen peroxide and potassium persulfate aqueous solution dropwise. After the dropwise addition is completed, continue to keep the reaction at the temperature for 2-4 h. After the reaction is completed, adjust the pH of the reaction solution to 6-8 with ammonia water to obtain a slightly yellow milky white styrene-acrylic emulsion, which is the inherently flame retardant high elasticity styrene-acrylic emulsion.

[0013] The molar ratio of glycine, paraformaldehyde, and dimethyl phosphite is 1.0-1.2:2.0-4.0:4.0.

[0014] In step (1), after removing the solvent tetrahydrofuran, the following treatment is required: first, wash with a small amount of water, then dry with anhydrous sodium sulfate, and finally perform solid-liquid separation. The pale yellow viscous liquid obtained after solid-liquid separation is the phosphorus-nitrogen integrated functional compound. The washing and drying operation is as follows: after washing with water, let it stand to separate into layers, separate the inorganic phase and retain the organic phase, and then add anhydrous sodium sulfate to the organic phase for drying.

[0015] In steps (1), (2), and (3), the dropping rate is 1-2 seconds / drop; in step (1), the time for continuing the reaction at a constant temperature after the dropping is completed is 7-9 hours; in step (2), the time for continuing the reaction at a constant temperature after the dropping is completed is 1-2 hours; in step (3), the time for both the low-temperature reaction and the temperature-controlled reaction after the dropping is completed is 7-9 hours.

[0016] In step (2), the molar ratio of thionyl chloride to the phosphorus-nitrogen integrated functional compound is 1.1-1.2:1.

[0017] In step (2), the catalyst is N,N-dimethylformamide (DMF), n-dodecyltrimethylammonium chloride, pyridine, or triethylamine; the amount of catalyst used is 3-6% of the mass of thionyl chloride.

[0018] In step (3), the molar ratio of phenolic hydroxy cashew phenol to acyl chloride modified flame retardant functional monomer is 1:1.0-1.2; the amount of triethylamine used is 0.5-1.2 times the mass of phenolic hydroxy cashew phenol.

[0019] In step (4), the mass ratio of starch to water is 1:1-1:4, the etherifying agent is 2,3-epoxypropyltrimethylammonium chloride or 3-chloro-2-hydroxypropyltrimethylammonium chloride, the amount of etherifying agent is 5%-20% of the starch mass, the concentration of hydrogen peroxide is 2-3%, and the amount of hydrogen peroxide is 0.5-2 times the starch mass.

[0020] In step (5), the amount of high-flexibility flame-retardant monomer used is 10%-30% of the mass of cationic etherified starch aqueous solution, the amount of styrene used is 0.5-5 times the mass of high-flexibility flame-retardant monomer, the amount of butyl acrylate used is 0.3-2 times the mass of high-flexibility flame-retardant monomer, and the amount of acrylic acid used is 0.05-0.5 times the mass of high-flexibility flame-retardant monomer; the amount of potassium persulfate used is 2%-10% of the total mass of high-flexibility flame-retardant monomer, styrene, butyl acrylate, and acrylic acid; the concentration of hydrogen peroxide is 2-3%, and the amount used is 0.3-1 times the total mass of high-flexibility flame-retardant monomer, styrene, butyl acrylate, and acrylic acid.

[0021] In step (2), the solvent is dichloroethane or chloroform; in step (3), the solvent is dichloroethane or chloroform.

[0022] In step (1), the amount of tetrahydrofuran used as a solvent is limited to the point that it can completely dissolve paraformaldehyde and glycine during the reaction. However, in order to ensure smooth flow of the system during stirring and make the reaction more balanced within the system, the amount of tetrahydrofuran can be increased appropriately. Similarly, in steps (2) and (3), the amount of solvent used is also limited to the point that it can completely dissolve the raw materials. However, in order to ensure smooth flow of the system during stirring and make the reaction more balanced within the system, the amount of solvent used in steps (2) and (3) can be increased appropriately.

[0023] The reaction process in step (1) is shown in the following equation:

[0024] .

[0025] The reaction processes in steps (2) and (3) are shown in the following equation:

[0026] .

[0027] The reaction process in step (5) is shown in the following formula:

[0028] .

[0029] The advantages of this invention are that the prepared product simultaneously possesses multiple advantages such as flame retardancy, high elasticity, soap-free properties, and water resistance. Firstly, the flame-retardant function of this copolymer originates from the abundant flame-retardant groups in the high-phosphorus flame retardant with reactive functional groups; it is rich in phosphorus, halogen-free, environmentally friendly, and has a high char formation rate. Secondly, the high elasticity and toughening effect comes from the flexible groups in the functional monomer HOOC-NP2 and the large number of flexible segments in cashew nut shell phenol. Thirdly, the soap-free synthesis avoids the yellowing and foul odor problems caused by high emulsifier content. Fourthly, the water resistance is improved due to the cationization of starch. Fifthly, the inherently flame-retardant and high-elasticity emulsion of this invention allows for free adjustment of the proportions of flame-retardant groups, cashew nut shell phenol, styrene, acrylic acid, etc., and a reasonable proportion can optimize the copolymer's performance. This product is green, environmentally friendly, and low-cost, and has wide application value. Attached Figure Description

[0030] Figure 1 The infrared spectrum of the product obtained in step (1) of Example 1;

[0031] Figure 2 The nuclear magnetic resonance spectrum of the product obtained in step (1) of Example 1 is shown. Detailed Implementation

[0032] The feasibility of the technical solution of the present invention is illustrated by the following examples, but the scope of protection of the present invention should not be limited to the specific examples below. Example 1

[0033] (1) In a three-necked flask equipped with a stirrer, thermometer and reflux condenser, add 252 g (2.8 mol) paraformaldehyde, 152 g (2.0 mol) glycine and 400 mL tetrahydrofuran. Stir the reaction mixture and heat it to 66 °C. Then slowly add 440 g (4.0 mol) dimethyl phosphite dropwise over 1 hour, one drop every 1-2 seconds. After the addition is complete, continue the reaction at about 66 °C for 8 hours. After the reaction is complete, remove the solvent by rotary evaporation to obtain the crude product. Wash the crude product with 60 mL of water. After washing, allow it to stand and separate into layers. Separate the inorganic phase and add anhydrous sodium sulfate to the organic phase for drying. After drying, filter to obtain 782 g of pale yellow transparent liquid, which is the phosphorus-nitrogen integrated functional compound (HOOC-NP2).

[0034] (2) In a 500ml three-necked flask equipped with a stirrer, thermometer and reflux condenser, add 329g (1.0mol) HOOC-NP2 and 150 mL dichloroethane, add 6.0 g DMF as catalyst, keep the temperature at about 10℃, slowly add 130.9 g (1.1mol) thionyl chloride to the reaction flask, one drop every 1-2 seconds. After the addition is complete, heat with stirring and slowly raise the temperature to 75℃. Continue stirring and keep the reaction at 75℃ for 1.5h. After the reaction is complete, the product solution is obtained. Add saturated saline and 5% sodium hydroxide solution to the product solution for washing. After washing, let it stand to separate the layers, separate the inorganic phase and add anhydrous sodium sulfate to the organic phase for drying. After filtration, a dichloroethane solution of acyl chloride modified flame retardant functional monomer is obtained. Rotary evaporation is used to remove the solvent dichloroethane to obtain the acyl chloride modified flame retardant functional monomer (ClOC-NP2).

[0035] (3) Mix 30.25g (0.1mol) of commercially available phenolic hydroxycatechol with 100ml of dichloroethane solvent and add to the reaction flask. Add 20.2g (0.2mol) of triethylamine. Dissolve 34.55g (0.1mol) of the prepared ClOC-NP2 in 50ml of dichloroethane at a constant temperature of -5℃ and add it dropwise to the reaction flask at a rate of 2 drops / s. After the addition is complete, maintain the low temperature for 8h. Then raise the temperature to 10℃ and continue to maintain the temperature for 8h until the reaction is complete. After the reaction is complete, filter to obtain a crude liquid product. Wash the crude liquid product successively with 2% acetic acid solution, 10% NaOH solution, and saturated saline solution. Then dry it with anhydrous sodium sulfate. Finally, perform solid-liquid separation and remove the solvent by rotary evaporation to obtain a light yellow viscous liquid, which is the high-flexibility flame-retardant monomer.

[0036] (4) Add 40g of starch and 120g of water to a four-necked reaction flask equipped with temperature control and mechanical stirring. Heat the flask to 55°C in a water bath, add an appropriate amount of ammonia to adjust the pH to 9, then add 5g of etherifying agent 2,3-epoxypropyltrimethylammonium chloride, keep warm and stir for 1.5h, then add 30g of 3% hydrogen peroxide, keep warm for 45min, then heat to 85°C and continue the reaction for 0.5h. After the reaction is complete, a transparent cationic etherified starch aqueous solution is obtained.

[0037] (5) Add 160g of cationic etherified starch aqueous solution to a four-necked reaction flask equipped with temperature control and mechanical stirring. Heat the flask to 70°C in a water bath, and add hydrogen peroxide and potassium persulfate aqueous solution dropwise while maintaining the dropwise addition. Add 20g of high-flexibility flame-retardant monomer and 50g of styrene, and carry out a prepolymerization reaction for 1 hour. Then add 25g of butyl acrylate and 5g of acrylic acid, and carry out a repolymerization reaction for 1 hour. At the same time as the repolymerization reaction is completed, add hydrogen peroxide and potassium persulfate aqueous solution dropwise. After the dropwise addition is completed, continue to keep the reaction at the temperature for 3 hours. After the reaction is completed, adjust the pH of the reaction solution to 8 with ammonia water to obtain a slightly yellowish milky white styrene-acrylic emulsion, which is the inherently flame-retardant high-elasticity styrene-acrylic emulsion. The mass concentration of hydrogen peroxide is 3%, and the amount used is 50g; the amount of potassium persulfate is 5g, and the concentration of the potassium persulfate aqueous solution is 20%. Example 2

[0038] (1) In a three-necked flask equipped with a stirrer, thermometer and reflux condenser, add 252 g (2.8 mol) paraformaldehyde, 152 g (2.0 mol) glycine and 400 mL tetrahydrofuran. Stir the reaction mixture and heat it to 66 °C. Then slowly add 440 g (4.0 mol) dimethyl phosphite dropwise over 1 hour, one drop every 1-2 seconds. After the addition is complete, continue the reaction at about 66 °C for 8 hours. After the reaction is complete, remove the solvent by rotary evaporation to obtain the crude product. Wash the crude product with 60 mL of water. After washing, allow it to stand and separate into layers. Separate the inorganic phase and add anhydrous sodium sulfate to the organic phase for drying. After drying, filter to obtain 782 g of pale yellow transparent liquid, which is the phosphorus-nitrogen integrated functional compound (HOOC-NP2).

[0039] (2) In a 500ml three-necked flask equipped with a stirrer, thermometer and reflux condenser, add 329g (1.0mol) HOOC-NP2 and 100 mL dichloroethane, add 7.0 g DMF as catalyst, keep the temperature at about 10℃, slowly add 142.8 g (1.2mol) thionyl chloride to the reaction flask, one drop every 1-2 seconds. After the addition is complete, heat with stirring and slowly raise the temperature to 75℃. Continue stirring and keep the reaction at 75℃ for 1.5h. After the reaction is complete, the product solution is obtained. Add saturated saline and 5% sodium hydroxide solution to the product solution for washing. After washing, let it stand to separate the layers, separate the inorganic phase and add anhydrous sodium sulfate to the organic phase for drying. After filtration, the dichloroethane solution of the acyl chloride modified flame retardant functional monomer is obtained. The solvent dichloroethane is removed by rotary evaporation to obtain the acyl chloride modified flame retardant functional monomer (ClOC-NP2).

[0040] (3) Mix 30.25g (0.1mol) of commercially available phenolic hydroxy cashew phenol with 100ml of dichloroethane solvent and add it to the reaction flask. Add 20.2g (0.2mol) of triethylamine. Dissolve the above-prepared ClOC-NP234.55g (0.1mol) in 50ml of dichloroethane at a constant temperature of -5℃ and add it to the reaction flask at a dropping rate of 2 drops / s. After the addition is completed, keep the reaction at a low temperature for 6h. Then raise the temperature to 15℃ and continue to keep the reaction at a high temperature for 6h. After the reaction is completed, filter to obtain a liquid crude product. Wash the liquid crude product with 2% acetic acid solution, 10% NaOH solution and saturated saline solution in sequence. Then dry it with anhydrous sodium sulfate. Finally, perform solid-liquid separation and remove the solvent by rotary evaporation to obtain a light yellow viscous liquid, which is the high-flexibility flame retardant monomer.

[0041] (4) Add 60g of starch and 120g of water to a four-necked reaction flask equipped with temperature control and mechanical stirring. Heat the flask to 55°C in a water bath, add an appropriate amount of ammonia to adjust the pH to about 9, then add 10g of etherifying agent 2,3-epoxypropyltrimethylammonium chloride, keep warm and stir for 1.5h, then add 45g of hydrogen peroxide, keep warm for 45min, then heat to 85°C and continue the reaction for 0.5h. After the reaction is complete, a transparent cationic etherified starch aqueous solution is obtained.

[0042] (5) Add 180 g of cationic etherified starch aqueous solution to a four-necked reaction flask equipped with temperature control and mechanical stirring. Heat the flask to 70°C in a water bath, and add hydrogen peroxide and potassium persulfate aqueous solution dropwise while maintaining the dropwise addition. Add 40 g of highly flexible flame-retardant monomer and 35 g of styrene, and carry out a prepolymerization reaction for 1.5 h. Then add 20 g of butyl acrylate and 5 g of acrylic acid, and carry out a repolymerization reaction for 1.5 h. At the same time as the repolymerization reaction is completed, add hydrogen peroxide and potassium persulfate aqueous solution dropwise. After the dropwise addition is completed, continue to keep the reaction at the temperature for 3 h. After the reaction is completed, adjust the pH of the reaction solution to 8 with ammonia water to obtain a slightly yellowish milky white styrene-acrylic emulsion, which is the inherently flame-retardant high-elasticity styrene-acrylic emulsion. The mass concentration of hydrogen peroxide is 3%, and the amount used is 60 g; the amount of potassium persulfate is 6 g, and the concentration of the potassium persulfate aqueous solution is 10%. Example 3

[0043] Bisphenol A-bis(diphenyl phosphate) (BDP), resorcinol (diphenyl phosphate) (RDP), ammonium polyphosphate type II (APP), piperazine pyrophosphate (PPAP), aluminum hydroxide, triazine charring agent (CFA), and epoxy resin were mixed in a mass ratio of 3.5:2.0:2.0:3.0:2.5:2.0:2.0 to prepare a mixture of the above materials with a total mass of 15.0g. The mixture was then added to a mixing container. Then, 26g of the inherently flame-retardant high-elasticity styrene-acrylic emulsion of Example 1 of this invention, 15g of water, 0.4g of emulsifier, and 0.4g of defoamer were added and stirred until evenly dispersed to obtain the flame-retardant coating adhesive.

[0044] The flame-retardant coating adhesive was scraped onto the back of the fabric (the fabric was natural white polyester fabric with a weight of 200g, i.e., the weight of each square meter of fabric was 200g), and baked (150℃, 180s) to obtain a low-smoke toxicity, high-efficiency flame-retardant polyester sofa textile fabric (sample 1), with a weight gain of 98.8g (i.e., the weight of the coating adhesive coated per square meter of fabric was 98.8g). Example 4

[0045] Bisphenol A-bis(diphenyl phosphate) (BDP), resorcinol (diphenyl phosphate) (RDP), ammonium polyphosphate type II (APP), piperazine pyrophosphate (PPAP), aluminum hydroxide, triazine charring agent (CFA), and epoxy resin were mixed in a mass ratio of 3.5:2.0:2.0:3.0:2.5:2.0:2.0 to prepare a mixture of the above materials with a total mass of 15.0g. The mixture was then added to a mixing container. Then, 26g of conventional commercially available 716 acrylate emulsion, 15g of water, 0.4g of emulsifier, and 0.4g of defoamer were added and stirred until evenly dispersed to obtain a flame-retardant coating adhesive (this formula does not contain the inherently flame-retardant high-elasticity styrene-acrylic emulsion of this invention).

[0046] The above flame-retardant coating adhesive was scraped onto the back of the fabric (the fabric is natural white polyester fabric with a weight of 200g, that is, the weight of each square meter of fabric is 200g), and baked (150℃, 180s) to obtain a low smoke toxicity and high efficiency flame-retardant polyester sofa textile fabric (sample 2), with a weight gain of 100.6g (that is, the weight of the coating adhesive is 100.6g per square meter of fabric). Example 5

[0047] Bisphenol A-bis(diphenyl phosphate) (BDP), resorcinol (diphenyl phosphate) (RDP), ammonium polyphosphate type II (APP), piperazine pyrophosphate (PPAP), aluminum hydroxide, triazine charring agent (CFA), and epoxy resin were mixed in a mass ratio of 3.5:2.0:2.0:3.0:2.5:2.0:2.0 to prepare a mixture of the above materials with a total mass of 15.0g. The mixture was then added to a mixing container. Then, 26g of the inherently flame-retardant high-elasticity styrene-acrylic emulsion of Example 2 of this invention, 15g of water, 0.4g of emulsifier, and 0.4g of defoamer were added and stirred until evenly dispersed to obtain the flame-retardant coating adhesive.

[0048] The flame-retardant coating adhesive was scraped onto the back of the fabric (the fabric was natural white polyester fabric with a weight of 200g, i.e., the weight of each square meter of fabric was 200g), and baked (150℃, 180s) to obtain a low-smoke toxicity, high-efficiency flame-retardant polyester sofa textile fabric (sample 3), with a weight gain of 99.6g (i.e., the weight of the coating adhesive was 99.6g per square meter of fabric).

[0049] Based on tactile feedback, Samples 1 and 3, which incorporated the inherently flame-retardant, high-elasticity styrene-acrylic emulsion of this invention, were noticeably softer due to the presence of flexible segments such as cashew phenol; while Sample 2, without the additive, was harder. In practical applications, softer fabrics better meet market demands. Softness ranking: Sample 3 > Sample 1, and both are significantly softer than Sample 2.

[0050] Referring to the BS5852 flame retardancy test standard, samples 1, 2, and 3 were respectively covered with specified polyurethane foam and placed under a specified burner for ignition. The butane flame height was 35 mm, and after the flame was stabilized for 30 seconds, the samples were continuously burned with the flame for 20 seconds to test their flame retardancy performance. The test results are shown in Table 1.

[0051]

[0052] As can be clearly seen from the table, the flame-retardant coating adhesive with the inherently flame-retardant high-elasticity styrene-acrylic emulsion provided by the present invention has a significant flame-retardant effect.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Any equivalent substitutions or partial improvements made under the technical essence of the present invention shall be considered to be within the protection scope of the present invention.

Claims

1. A method for preparing a high-elasticity, inherently flame-retardant styrene-acrylic emulsion, characterized by The method comprises the following steps: The method comprises the following steps:

2. The preparation method of the intrinsic flame-retardant high-elasticity styrene-acrylic emulsion according to claim 1, characterized in that (1) mixing polyformaldehyde, glycine and tetrahydrofuran and heating to 60-70 DEG C, then adding dimethyl phosphite dropwise, and continuing to heat until the reaction is complete; after the reaction is completed, removing the solvent tetrahydrofuran to obtain a light yellow viscous liquid, which is a phosphorus-nitrogen integrated functional compound; (2) dissolving the phosphorus-nitrogen integrated functional compound in a solvent and adding a catalyst, and then adding chlorosulfuric acid dropwise at a temperature of 0-15 DEG C; after the dropwise addition is completed, heating to 70-80 DEG C and continuing to heat until the reaction is complete to obtain a product solution; washing the product solution with saturated brine and sodium hydroxide solution, then separating the inorganic phase, adding anhydrous sodium sulfate to the organic phase for drying, and after the drying is completed, separating the solid and liquid phases, removing the solvent from the liquid product obtained by the solid-liquid separation to obtain an acyl chloride modified flame-retardant functional monomer; (3) mixing the phenolic hydroxyl cardanol with a solvent and adding triethylamine, dissolving the acyl chloride modified flame-retardant functional monomer in a solvent to prepare a flame-retardant functional monomer solution, and then adding the flame-retardant functional monomer solution dropwise at a temperature of -10-0 DEG C; after the dropwise addition is completed, first performing a low-temperature reaction at a temperature of -10-0 DEG C, and then continuing to heat until the reaction is complete at a temperature of 5-15 DEG C; after the reaction is completed, filtering to obtain a liquid crude product, washing the liquid crude product with acetic acid solution, NaOH solution and saturated brine in sequence, then drying with anhydrous sodium sulfate, and after the drying is completed, separating the solid and liquid phases to obtain a product solution, and removing the solvent from the product solution to obtain a light yellow viscous liquid, which is a high-flexibility flame-retardant monomer; (4) mixing starch and water, heating the water bath to 40-60 DEG C, adding ammonia water to adjust the pH value to 8.5-10, adding an etherification agent, adding hydrogen peroxide after heating and stirring for 1-2 h, continuing to heat for 30-60 min, then heating to 70-90 DEG C and continuing to react for 0.3-1 h, and after the reaction is completed, obtaining a transparent cationic etherified starch aqueous solution; ​ (5) the cationic etherified starch aqueous solution is warmed to 60-85℃ in a water bath, and an aqueous solution of hydrogen peroxide and potassium peroxydisulfate is added dropwise, the dropping state is maintained, high-flexibility flame-retardant monomers and styrene are added, a first polymerization reaction is performed for 0.5-2 h, then butyl acrylate and acrylic acid are added, a second polymerization reaction is performed for 0.5-2 h, the second polymerization reaction is completed at the same time as the completion of the dropping of the aqueous solution of hydrogen peroxide and potassium peroxydisulfate, the dropping is completed, and a post-reaction is continued for 2-4 h, the reaction is completed, the pH of the reaction completion liquid is adjusted to 6-8 with ammonia water, a slightly yellowish white styrene-acrylic emulsion is obtained, and the styrene-acrylic emulsion is a high-elasticity styrene-acrylic emulsion of intrinsic flame retardance.

3. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: The molar ratio of the glycine, the paraformaldehyde, and the dimethyl phosphite is 1.0-1.2:2.0-4.0:4.

0.

4. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (1), the step (2), and the step (3), the dropping speed is 1-2 seconds / drop; in the step (1), the post-reaction time after the completion of the dropping is 7-9 h; in the step (2), the post-reaction time after the completion of the dropping is 1-2 h; and in the step (3), the low-temperature reaction and the post-reaction time after the completion of the dropping are both 7-9 h.

5. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (2), the molar ratio of the thionyl chloride to the phosphorus-nitrogen integrated functional compound is 1.1-1.2:

1.

6. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (2), the catalyst is N,N-dimethylformamide, n-dodecyl trimethylammonium chloride, pyridine, or triethylamine; and the catalyst is used in an amount of 3-6% of the mass of the thionyl chloride.

7. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (3), the molar ratio of the phenolic hydroxyl cashew phenol to the acyl chloride-modified flame-retardant functional monomer is 1:1.0-1.2, and the amount of triethylamine is 0.5-1.2 times the mass of the phenolic hydroxyl cashew phenol.

8. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (4), the mass ratio of the starch to water is 1:1-1:4, the etherifying agent is 2,3-epoxypropyl trimethylammonium chloride or 3-chloro-2-hydroxypropyl trimethylammonium chloride, the amount of the etherifying agent is 5%-20% of the mass of the starch, and the concentration of the hydrogen peroxide is 2-3%, and the amount of the hydrogen peroxide is 0.5-2 times the mass of the starch.

9. The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (5), the amount of the high-flexibility flame-retardant monomer is 10%-30% of the mass of the cationic etherified starch aqueous solution, the amount of the styrene is 0.5-5 times the mass of the high-flexibility flame-retardant monomer, the amount of the butyl acrylate is 0.3-2 times the mass of the high-flexibility flame-retardant monomer, the amount of the acrylic acid is 0.05-0.5 times the mass of the high-flexibility flame-retardant monomer, the amount of the potassium peroxydisulfate is 2%-10% of the total mass of the high-flexibility flame-retardant monomer, the styrene, the butyl acrylate, and the acrylic acid, the concentration of the hydrogen peroxide is 2-3%, and the amount of the hydrogen peroxide is 0.3-1 times the total mass of the high-flexibility flame-retardant monomer, the styrene, the butyl acrylate, and the acrylic acid. 10.The preparation method of the intrinsically flame-retardant high-elasticity styrene-acrylic emulsion according to claim 2, characterized in that: In the step (2), the solvent is dichloroethane or chloroform; and in the step (3), the solvent is dichloroethane or chloroform.

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