A flame-retardant composite color-spun yarn and its preparation method

Abstract

The present invention discloses a flame-retardant composite color-spun yarn and a preparation method thereof. Polyamic acid is formed by reacting 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine and a modified monomer, and then blended with a functional filler to obtain a spinning solution. The spinning solution is spun and imidized under high-temperature conditions to obtain reinforced fibers. The reinforced fibers are dyed to obtain dyed fibers. The dyed fibers are subjected to processes such as opening, carding, drawing, roving and spinning to obtain a pretreated yarn. The pretreated yarn is soaked in a ferric chloride solution, taken out and dried to obtain a color-spun yarn. When the color-spun yarn burns, the internal organic phosphorus can generate phosphoric anhydride and phosphide. The phosphoric anhydride can dehydrate and carbonize the color-spun yarn, forming a carbonized layer on the surface to isolate the external heat. At the same time, doping with silicon, nitrogen and boron elements further improves the compactness of the carbon layer and can release nitrogen and nitrogen dioxide gases, thereby reducing the oxygen content and enhancing the flame-retardant effect.

Description

Technical Field

[0001] The present invention relates to the technical field of colored spun yarn preparation, and specifically relates to a flame-retardant composite colored spun yarn and a preparation method thereof. Background Art

[0002] Colored spun yarn is to first dye the fibers into colored fibers, and then spin two or more different colored fibers after sufficient mixing to form a yarn with a unique mixed-color effect. Humans have a long history of using fiber materials. Natural fibers such as cotton, linen, silk, and wool, as well as synthetic fibers such as nylon, acrylic, and Teflon, have always been important heat-insulating materials for humans. Although synthetic fiber materials were born relatively late, their high performance, high strength, high precision, and other characteristics are not possessed by natural fiber materials. Therefore, most of the fabrics on the market today are composite fabrics prepared from synthetic fibers. However, synthetic fibers have poor flame retardancy. During combustion, they will produce dripping and even smoldering, resulting in secondary combustion, which narrows the scope of use of colored spun yarn. Summary of the Invention

[0003] The purpose of the present invention is to provide a flame-retardant composite colored spun yarn and a preparation method thereof, which solves the problem of poor flame retardancy of colored spun yarn at the present stage.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A preparation method of a flame-retardant composite colored spun yarn specifically includes the following steps:

[0006] Step S1: Mix the modified filler, 3-isocyanatopropylmethyldimethoxysilane, and toluene, and stir at a rotation speed of 120 - 150 r / min and a temperature of 25 - 30 °C for 3 - 5 h to obtain a functional filler. Mix 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, a modified monomer, and N,N-dimethylacetamide evenly, stir at a rotation speed of 120 - 150 r / min and a temperature of 40 - 45 °C for 3 - 5 h, then cool down to 0 °C and stir for 40 - 45 h, add the functional filler, and stir for 3 - 5 h to obtain a spinning solution.

[0007] Step S2: Under the condition of nitrogen with a pressure of 0.3 - 0.35 MPa, extrude the spinning solution through a spinneret with 100 holes and a diameter of 75 microns into a coagulation bath, and then keep it warm at 100 °C, 280 °C, and 350 °C for 1 h respectively to obtain reinforced fibers. Dye the reinforced fibers respectively to obtain dyed fibers. Perform the processes of opening, carding, drawing, roving, and spinning on the dyed fibers to obtain a pretreated yarn. Immerse the pretreated yarn in deionized water, keep it warm at 60 - 70 °C for 3 - 5 h, take it out and dry it to obtain a flame-retardant composite colored spun yarn.

[0008] Furthermore, the dosage ratio of the modified filler described in step S1 to 3-isocyanatopropylmethyldimethoxysilane is 1 g: 3 mL, and the dosage ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer, N,N-dimethylacetamide, and the functional filler is 55 mmol: 40 mmol: 15 mmol: 60 mL: 5 g.

[0009] Furthermore, the modified monomer is prepared by the following steps:

[0010] Step A1: Mix phosphorus oxychloride, 2,2-dimethylolpropionic acid, and N,N-dimethylformamide evenly, and carry out a reaction for 6 - 8 h under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 100 - 110 °C to obtain intermediate 1. Dissolve intermediate 1 in N,N-dimethylformamide, introduce nitrogen protection, stir and add formic acid under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 30 - 40 °C, and carry out a reaction for 4 - 6 h to obtain a phosphorus additive. Mix the phosphorus additive, KH550, dicyclohexylcarbodiimide, and N,N-dimethylformamide, and carry out a reaction for 3 - 5 h under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 30 - 40 °C to obtain a phosphorus modifier;

[0011] Step A2: Mix octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, tetramethylammonium hydroxide, and dimethyl sulfoxide evenly, introduce nitrogen protection, and carry out a reaction for 3 - 5 h under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 90 - 100 °C to obtain a diamine-terminated polysiloxane. Mix the diamine-terminated polysiloxane, the phosphorus modifier, and N,N-dimethylformamide evenly, introduce nitrogen protection, and carry out a reaction for 40 - 45 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 65 - 70 °C to obtain the modified monomer.

[0012] Furthermore, the molar ratio of the phosphorus oxychloride to 2,2-dimethylolpropionic acid described in step A1 is 1:1, the molar ratio of intermediate 1 to formic acid is 1:1, and the molar ratio of the phosphorus additive, KH550, and dicyclohexylcarbodiimide is 1:1:1.1.

[0013] Furthermore, the molar ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide described in step A2 is 1.8:0.6:2:3, and the molar ratio of the double bond on the diamine-terminated polysiloxane to the phosphorus modifier is 1:1.

[0014] Further, the modified filler is prepared by the following steps:

[0015] Step B1: Mix melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve and methanol, stir and add hydrochloric acid solution under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 20 - 25 °C, and react for 3 - 5 h under the condition of heating to 65 - 70 °C to obtain Intermediate 2. Mix 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether and N,N-dimethylformamide evenly, and react for 2 - 4 h under the conditions of a rotation speed of 150 - 200 r / min and a temperature of 60 - 70 °C, then add sodium hydroxide solution, heat to 80 - 85 °C, and react for 4 - 6 h to obtain Intermediate 3;

[0016] Step B2: Mix Intermediate 3, sodium periodate, tetrahydrofuran and deionized water evenly, stir and add hydrochloric acid solution under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 25 - 30 °C, and react for 3 - 4 h to obtain Intermediate 4. Mix Intermediate 2, Intermediate 4, 5A molecular sieve and N,N-dimethylformamide evenly, and react for 10 - 15 h under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 60 - 70 °C to obtain Intermediate 5;

[0017] Step B3: Mix Intermediate 5, 2-aminoterephthalic acid and N,N-dimethylformamide, react for 4 - 6 h under the conditions of a rotation speed of 150 - 200 r / min, a temperature of 20 - 25 °C and a pH value of 11 - 12, then adjust the pH to acidic, heat to 85 - 90 °C, add DOPO, and continue to react for 6 - 8 h to obtain an organic ligand. Mix the organic ligand, samarium nitrate hexahydrate and N,N-dimethylformamide evenly, stir and add deionized water under the conditions of a rotation speed of 120 - 150 r / min and a temperature of 20 - 25 °C, stir for 20 - 30 min, then heat to 105 - 110 °C, and react for 10 - 15 h to obtain the modified filler.

[0018] Further, the dosage ratio of the melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve and hydrochloric acid solution described in Step B1 is 50 mmol:150 mmol:1 g:2 mL, the mass fraction of the hydrochloric acid solution is 10%, and the dosage ratio of the 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether and sodium hydroxide solution is 10 mmol:10 mmol:0.5 g:30 mL, and the mass fraction of the sodium hydroxide solution is 10%.

[0019] Further, the dosage ratio of intermediate 3, sodium periodate, tetrahydrofuran, deionized water and hydrochloric acid solution described in step B2 is 5 mmol: 15 mmol: 40 mL: 10 mL: 3.5 mL, the mass fraction of the hydrochloric acid solution is 5%, and the dosage ratio of intermediate 2, intermediate 4 and 5A molecular sieve is 10 mmol: 30 mmol: 2 g.

[0020] Further, the molar ratio of intermediate 5, 2-aminoterephthalic acid and DOPO described in step B3 is 1:3:3, and the dosage ratio of the organic ligand, samarium nitrate hexahydrate, N,N-dimethylformamide and deionized water is 1.5 mmol: 1 mmol: 50 mL: 5 mL.

[0021] The beneficial effects of the present invention: A flame-retardant composite color spinning yarn prepared by the present invention reacts 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine and a modified monomer to form polyamic acid, and then blends with a functional filler to obtain a spinning solution, spins and imidizes under high temperature conditions to obtain a reinforced fiber, dyes the reinforced fiber to obtain a dyed fiber, and performs the processes of opening, carding, drawing, roving and spinning on the dyed fiber to obtain a pretreated yarn. The pretreated yarn is soaked in a ferric chloride solution, taken out and dried to obtain a color spinning yarn. The modified monomer is prepared by reacting phosphorus oxychloride and 2,2-dimethylolpropionic acid, so that the chlorine atom site on phosphorus oxychloride reacts with the hydroxyl group on 2,2-dimethylolpropionic acid to obtain intermediate 1. Intermediate 1 is treated with formic acid to convert the P-Cl bond on intermediate 1 into a P-H bond to obtain a phosphorus additive. The phosphorus additive and KH550 are reacted so that the carboxyl group on the phosphorus additive reacts with the amino group on KH550 to obtain a phosphorus modifier. Octamethylcyclotetrasiloxane and 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane are ring-opened and then polymerized with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane to form a diamine-terminated polysiloxane. The diamine-terminated polysiloxane and the phosphorus modifier are reacted so that the double bond on the diamine-terminated polysiloxane reacts with the P-H bond on the phosphorus modifier to obtain a modified monomer.

[0022] The functional filler uses melamine and 3,4-dihydroxybenzaldehyde as raw materials, reacting the amino group on melamine with the aldehyde group on 3,4-dihydroxybenzaldehyde to obtain intermediate 2. React 4-hydroxyphenylboronic acid pinacol ester with epichlorohydrin, reacting the phenolic hydroxyl group on 4-hydroxyphenylboronic acid pinacol ester with the epoxy group on epichlorohydrin, and then closing the ring under the action of sodium hydroxide solution to form a new epoxy group, obtaining intermediate 3. Treat intermediate 3 with sodium periodate to transform the phenylboronic acid pinacol ester structure into a phenylboronic acid structure, obtaining intermediate 4. React intermediate 4 with intermediate 2, reacting the phenylboronic acid on intermediate 4 with the catechol structure on intermediate 2, obtaining intermediate 5. React intermediate 5 with 2-aminoterephthalic acid, reacting the epoxy group on intermediate 5 with the amino group on 2-aminoterephthalic acid, obtaining an organic ligand. React the organic ligand with samarium nitrate hexahydrate to form a samarium organic framework, obtaining a modified filler. Treat the modified filler with 3-isocyanatopropylmethyldimethoxysilane, reacting the hydroxyl group on the surface of the modified filler with the isocyanate group on 3-isocyanatopropylmethyldimethoxysilane, obtaining the functional filler.

[0023] When the colored spun yarn burns, the internal organic phosphorus can generate phosphoric anhydride and phosphide. The phosphoric anhydride can dehydrate and carbonize the colored spun yarn, forming a carbonized layer on the surface to isolate external heat. At the same time, doping with silicon, nitrogen, and boron elements further improves the compactness of the carbon layer, and can release nitrogen and nitrogen dioxide gases, thereby reducing the oxygen content and enhancing the flame retardancy effect. The organic framework containing rare earth metal samarium can reduce the generation of toxic smoke. When the pretreated yarn is soaked in deionized water, the siloxanes on the side chains of polyimide molecules and the siloxanes on the surface of the functionalized filler can hydrolyze and condense, and then form multiple carbon layers during the carbonization process, further enhancing the flame retardancy effect. Specific Embodiments

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] Example 1

[0026] A preparation method of a flame-retardant composite colored spun yarn specifically includes the following steps:

[0027] Step S1: Mix the modified filler, 3-isocyanatopropylmethyldimethoxysilane, and toluene, and stir for 3 h under the conditions of a rotation speed of 120 r / min and a temperature of 25 °C to obtain a functional filler. Mix 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer, and N,N-dimethylacetamide evenly, stir for 3 h under the conditions of a rotation speed of 120 r / min and a temperature of 40 °C, then cool down to 0 °C and stir for 40 h, add the functional filler, and stir for 3 h to obtain a spinning solution.

[0028] Step S2: Under the condition of nitrogen with a pressure of 0.3 MPa, extrude the spinning solution through a spinneret with 100 holes and a diameter of 75 microns into a coagulation bath, and then keep it warm for 1 h under the conditions of temperatures of 100 °C, 280 °C, and 350 °C respectively to obtain the reinforced fiber. Dye the reinforced fiber respectively to obtain the dyed fiber. Perform the processes of opening, carding, drawing, roving, and spinning on the dyed fiber to obtain the pretreated yarn. Immerse the pretreated yarn in deionized water, keep it warm for 3 h under the condition of a temperature of 60 °C, take it out and dry it to obtain the flame-retardant composite colored spun yarn.

[0029] The dosage ratio of the modified filler and 3-isocyanatopropylmethyldimethoxysilane described in Step S1 is 1 g:3 mL, and the dosage ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer, N,N-dimethylacetamide, and the functional filler is 55 mmol:40 mmol:15 mmol:60 mL:5 g.

[0030] The described modified monomer is prepared by the following steps:

[0031] Step A1: Mix phosphorus oxychloride, 2,2-bis(hydroxymethyl)propionic acid, and N,N-dimethylformamide evenly, and react for 6 h under the conditions of a rotation speed of 120 r / min and a temperature of 100 °C to obtain Intermediate 1. Dissolve Intermediate 1 in N,N-dimethylformamide, protect it with nitrogen, stir and add formic acid under the conditions of a rotation speed of 150 r / min and a temperature of 30 °C, and react for 4 h to obtain a phosphorus additive. Mix the phosphorus additive, KH550, dicyclohexylcarbodiimide, and N,N-dimethylformamide, and react for 3 h under the conditions of a rotation speed of 120 r / min and a temperature of 30 °C to obtain a phosphorus modifier.

[0032] Step A2: Mix octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, tetramethylammonium hydroxide, and dimethyl sulfoxide evenly. Under the protection of nitrogen, react for 3 h at a rotation speed of 120 r / min and a temperature of 90 °C to obtain diamine-terminated polysiloxane. Mix the diamine-terminated polysiloxane, phosphorus modifier, and N,N-dimethylformamide evenly. Under the protection of nitrogen, react for 40 h at a rotation speed of 150 r / min and a temperature of 65 °C to obtain the modified monomer.

[0033] The molar ratio of phosphorus oxychloride to 2,2-dimethylolpropionic acid described in Step A1 is 1:1, the molar ratio of Intermediate 1 to formic acid is 1:1, and the molar ratio of phosphorus additive, KH550, and dicyclohexylcarbodiimide is 1:1:1.1.

[0034] The molar ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide described in Step A2 is 1.8:0.6:2:3, and the molar ratio of the double bond on the diamine-terminated polysiloxane to the phosphorus modifier is 1:1.

[0035] The modified filler is prepared by the following steps:

[0036] Step B1: Mix melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve, and methanol. Under the condition of a rotation speed of 120 r / min and a temperature of 20 °C, stir and add hydrochloric acid solution, and react for 3 h under the condition of heating to 65 °C to obtain Intermediate 2. Mix 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl etherate, and N,N-dimethylformamide evenly. React for 2 h under the condition of a rotation speed of 150 r / min and a temperature of 60 °C, then add sodium hydroxide solution, and react for 4 h by heating to 80 °C to obtain Intermediate 3;

[0037] Step B2: Mix Intermediate 3, sodium periodate, tetrahydrofuran, and deionized water evenly. Under the condition of a rotation speed of 120 r / min and a temperature of 25 °C, stir and add hydrochloric acid solution, and react for 3 h to obtain Intermediate 4. Mix Intermediate 2, Intermediate 4, 5A molecular sieve, and N,N-dimethylformamide evenly. React for 10 h under the condition of a rotation speed of 120 r / min and a temperature of 60 °C to obtain Intermediate 5;

[0038] Step B3: Mix intermediate 5, 2-aminoterephthalic acid and N,N-dimethylformamide, react at a rotation speed of 150 r / min, a temperature of 20 °C, and a pH value of 11 for 4 h, then adjust the pH to acidic, raise the temperature to 85 °C, add DOPO, and continue to react for 6 h to obtain an organic ligand. Mix the organic ligand, samarium nitrate hexahydrate and N,N-dimethylformamide evenly, stir and add deionized water under the conditions of a rotation speed of 120 r / min and a temperature of 20 °C, stir for 20 min, then raise the temperature to 105 °C and react for 10 h to obtain the modified filler.

[0039] The dosage ratio of melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve and hydrochloric acid solution described in Step B1 is 50 mmol: 150 mmol: 1 g: 2 mL, the mass fraction of the hydrochloric acid solution is 10%, and the dosage ratio of 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether and sodium hydroxide solution is 10 mmol: 10 mmol: 0.5 g: 30 mL, and the mass fraction of the sodium hydroxide solution is 10%.

[0040] The dosage ratio of intermediate 3, sodium periodate, tetrahydrofuran, deionized water and hydrochloric acid solution described in Step B2 is 5 mmol: 15 mmol: 40 mL: 10 mL: 3.5 mL, the mass fraction of the hydrochloric acid solution is 5%, and the dosage ratio of intermediate 2, intermediate 4 and 5A molecular sieve is 10 mmol: 30 mmol: 2 g.

[0041] The molar ratio of intermediate 5, 2-aminoterephthalic acid and DOPO described in Step B3 is 1:3:3, and the dosage ratio of the organic ligand, samarium nitrate hexahydrate, N,N-dimethylformamide and deionized water is 1.5 mmol: 1 mmol: 50 mL: 5 mL.

[0042] Example 2

[0043] A preparation method of a flame-retardant composite color spinning yarn specifically includes the following steps:

[0044] Step S1: Mix the modified filler, 3-isocyanatopropylmethyldimethoxysilane and toluene, stir at a rotation speed of 120 - 150 r / min and a temperature of 25 °C for 4 h to obtain a functional filler. Mix 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer and N,N-dimethylacetamide evenly, stir at a rotation speed of 150 r / min and a temperature of 40 °C for 4 h, then cool down to 0 °C, stir for 45 h, add the functional filler, and stir for 4 h to obtain a spinning solution;

[0045] Step S2: Under the condition of nitrogen with a pressure of 0.3 MPa, the spinning solution is extruded into a coagulation bath through a spinneret with 100 holes and a diameter of 75 microns, and then kept at 100 °C, 280 °C and 350 °C for 1 h respectively to obtain reinforced fibers. The reinforced fibers are dyed respectively to obtain dyed fibers. The dyed fibers are subjected to processes of opening, carding, drawing, roving and spinning to obtain pretreated yarns. The pretreated yarns are soaked in deionized water and kept at 65 °C for 4 h, taken out and dried to obtain flame-retardant composite colored spun yarns.

[0046] The dosage ratio of the modified filler described in Step S1 to 3-isocyanatopropylmethyldimethoxysilane is 1 g:3 mL, and the dosage ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, modified monomer, N,N-dimethylacetamide and functional filler is 55 mmol:40 mmol:15 mmol:60 mL:5 g.

[0047] The modified monomer is prepared by the following steps:

[0048] Step A1: Phosphorus oxychloride, 2,2-dimethylolpropionic acid and N,N-dimethylformamide are mixed evenly and reacted for 7 h under the conditions of a rotation speed of 120 r / min and a temperature of 105 °C to obtain Intermediate 1. Intermediate 1 is dissolved in N,N-dimethylformamide, nitrogen is introduced for protection, and formic acid is added with stirring under the conditions of a rotation speed of 150 r / min and a temperature of 35 °C and reacted for 5 h to obtain a phosphorus additive. The phosphorus additive, KH550, dicyclohexylcarbodiimide and N,N-dimethylformamide are mixed and reacted for 4 h under the conditions of a rotation speed of 120 r / min and a temperature of 35 °C to obtain a phosphorus modifier;

[0049] Step A2: Octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, tetramethylammonium hydroxide and dimethyl sulfoxide are mixed evenly, nitrogen is introduced for protection, and reacted for 4 h under the conditions of a rotation speed of 150 r / min and a temperature of 95 °C to obtain a diamine-terminated polysiloxane. The diamine-terminated polysiloxane, phosphorus modifier and N,N-dimethylformamide are mixed evenly, nitrogen is introduced for protection, and reacted for 45 h under the conditions of a rotation speed of 150 r / min and a temperature of 65 °C to obtain a modified monomer.

[0050] The molar ratio of phosphorus oxychloride to 2,2-dimethylolpropionic acid described in Step A1 is 1:1, the molar ratio of Intermediate 1 to formic acid is 1:1, and the molar ratio of the phosphorus additive, KH550 and dicyclohexylcarbodiimide is 1:1:1.1.

[0051] The molar ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide described in Step A2 is 1.8:0.6:2:3, and the molar ratio of the double bonds on the diamine-terminated polysiloxane to the phosphorus modifier is 1:1.

[0052] The modified filler described above is prepared by the following steps:

[0053] Step B1: Mix melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve, and methanol, stir and add hydrochloric acid solution under the conditions of a rotation speed of 120 r / min and a temperature of 25 °C, and react for 4 h under the condition of heating to 65 °C to obtain Intermediate 2. Mix 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether, and N,N-dimethylformamide evenly, and react for 3 h under the conditions of a rotation speed of 150 r / min and a temperature of 65 °C, then add sodium hydroxide solution, heat to 80 °C, and react for 5 h to obtain Intermediate 3;

[0054] Step B2: Mix Intermediate 3, sodium periodate, tetrahydrofuran, and deionized water evenly, stir and add hydrochloric acid solution under the conditions of a rotation speed of 150 r / min and a temperature of 25 °C, and react for 5 h to obtain Intermediate 4. Mix Intermediate 2, Intermediate 4, 5A molecular sieve, and N,N-dimethylformamide evenly, and react for 15 h under the conditions of a rotation speed of 120 r / min and a temperature of 65 °C to obtain Intermediate 5;

[0055] Step B3: Mix Intermediate 5, 2-aminoterephthalic acid, and N,N-dimethylformamide, react for 5 h under the conditions of a rotation speed of 200 r / min, a temperature of 20 °C, and a pH value of 11, then adjust the pH to acidic, heat to 85 °C, add DOPO, and continue to react for 7 h to obtain an organic ligand. Mix the organic ligand, samarium nitrate hexahydrate, and N,N-dimethylformamide evenly, stir and add deionized water under the conditions of a rotation speed of 150 r / min and a temperature of 20 °C, stir for 25 min, then heat to 110 °C, and react for 10 h to obtain the modified filler.

[0056] The dosage ratio of melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve, and hydrochloric acid solution described in Step B1 is 50 mmol:150 mmol:1 g:2 mL, the mass fraction of the hydrochloric acid solution is 10%, and the dosage ratio of 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether, and sodium hydroxide solution is 10 mmol:10 mmol:0.5 g:30 mL, and the mass fraction of the sodium hydroxide solution is 10%.

[0057] The dosage ratio of intermediate 3, sodium periodate, tetrahydrofuran, deionized water and hydrochloric acid solution described in step B2 is 5 mmol: 15 mmol: 40 mL: 10 mL: 3.5 mL. The mass fraction of the hydrochloric acid solution is 5%. The dosage ratio of intermediate 2, intermediate 4 and 5A molecular sieve is 10 mmol: 30 mmol: 2 g.

[0058] The molar ratio of intermediate 5, 2-aminoterephthalic acid and DOPO described in step B3 is 1:3:3. The dosage ratio of the organic ligand, samarium nitrate hexahydrate, N,N-dimethylformamide and deionized water is 1.5 mmol: 1 mmol: 50 mL: 5 mL.

[0059] Example 3

[0060] A preparation method of a flame-retardant composite color-spun yarn specifically includes the following steps:

[0061] Step S1: Mix the modified filler, 3-isocyanatopropylmethyldimethoxysilane and toluene, and stir at a rotation speed of 150 r / min and a temperature of 30 °C for 5 h to obtain a functional filler. Mix 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer and N,N-dimethylacetamide evenly, stir at a rotation speed of 150 r / min and a temperature of 45 °C for h, then cool down to 0 °C, stir for 45 h, add the functional filler, and stir for 5 h to obtain a spinning solution.

[0062] Step S2: Under the condition of nitrogen with a pressure of 0.35 MPa, extrude the spinning solution through a spinneret with 100 holes and a diameter of 75 microns into a coagulation bath, and then keep it warm at 100 °C, 280 °C and 350 °C for 1 h respectively to obtain strengthened fibers. Dye the strengthened fibers respectively to obtain dyed fibers. Perform the processes of opening, carding, drawing, roving and spinning on the dyed fibers to obtain a pretreated yarn. Immerse the pretreated yarn in deionized water, keep it warm at 70 °C for 5 h, take it out and dry it to obtain the flame-retardant composite color-spun yarn.

[0063] The dosage ratio of the modified filler and 3-isocyanatopropylmethyldimethoxysilane described in step S1 is 1 g: 3 mL. The dosage ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, the modified monomer, N,N-dimethylacetamide and the functional filler is 55 mmol: 40 mmol: 15 mmol: 60 mL: 5 g.

[0064] The modified monomer is prepared by the following steps:

[0065] Step A1: Mix phosphorus oxychloride, 2,2-dimethylolpropionic acid, and N,N-dimethylformamide evenly. React for 8 h under the conditions of a rotation speed of 150 r / min and a temperature of 110 °C to obtain Intermediate 1. Dissolve Intermediate 1 in N,N-dimethylformamide, protect it by introducing nitrogen, stir and add formic acid under the conditions of a rotation speed of 200 r / min and a temperature of 40 °C, and react for 6 h to obtain a phosphorus additive. Mix the phosphorus additive, KH550, dicyclohexylcarbodiimide, and N,N-dimethylformamide, and react for 5 h under the conditions of a rotation speed of 150 r / min and a temperature of 40 °C to obtain a phosphorus modifier;

[0066] Step A2: Mix octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, tetramethylammonium hydroxide, and dimethyl sulfoxide evenly, protect it by introducing nitrogen, and react for 5 h under the conditions of a rotation speed of 150 r / min and a temperature of 100 °C to obtain a diamine-terminated polysiloxane. Mix the diamine-terminated polysiloxane, the phosphorus modifier, and N,N-dimethylformamide evenly, protect it by introducing nitrogen, and react for 45 h under the conditions of a rotation speed of 200 r / min and a temperature of 70 °C to obtain a modified monomer.

[0067] The molar ratio of phosphorus oxychloride to 2,2-dimethylolpropionic acid described in Step A1 is 1:1, the molar ratio of Intermediate 1 to formic acid is 1:1, and the molar ratio of the phosphorus additive, KH550, and dicyclohexylcarbodiimide is 1:1:1.1.

[0068] The molar ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and tetramethylammonium hydroxide described in Step A2 is 1.8:0.6:2:3, and the molar ratio of the double bond on the diamine-terminated polysiloxane to the phosphorus modifier is 1:1.

[0069] The modified filler is prepared by the following steps:

[0070] Step B1: Mix melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve, and methanol, stir and add hydrochloric acid solution under the conditions of a rotation speed of 150 r / min and a temperature of 25 °C, and react for 5 h under the condition of heating to 70 °C to obtain Intermediate 2. Mix 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl etherate, and N,N-dimethylformamide evenly, react for 4 h under the conditions of a rotation speed of 200 r / min and a temperature of 70 °C, then add sodium hydroxide solution, heat to 85 °C, and react for 6 h to obtain Intermediate 3;

[0071] Step B2: Mix intermediate 3, sodium periodate, tetrahydrofuran and deionized water evenly. Under the conditions of a rotation speed of 150 r / min and a temperature of 30 °C, stir and add hydrochloric acid solution, and react for 4 h to obtain intermediate 4. Mix intermediate 2, intermediate 4, 5A molecular sieve and N,N-dimethylformamide evenly. Under the conditions of a rotation speed of 150 r / min and a temperature of 70 °C, react for 15 h to obtain intermediate 5;

[0072] Step B3: Mix intermediate 5, 2-aminoterephthalic acid and N,N-dimethylformamide. Under the conditions of a rotation speed of 200 r / min, a temperature of 25 °C and a pH value of 12, react for 6 h, then adjust the pH to acidic, raise the temperature to 90 °C, add DOPO, and continue to react for 8 h to obtain an organic ligand. Mix the organic ligand, samarium nitrate hexahydrate and N,N-dimethylformamide evenly. Under the conditions of a rotation speed of 150 r / min and a temperature of 25 °C, stir and add deionized water. After stirring for 30 min, raise the temperature to 110 °C and react for 15 h to obtain a modified filler.

[0073] The dosage ratio of melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve and hydrochloric acid solution described in Step B1 is 50 mmol: 150 mmol: 1 g: 2 mL. The mass fraction of the hydrochloric acid solution is 10%. The dosage ratio of 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether and sodium hydroxide solution is 10 mmol: 10 mmol: 0.5 g: 30 mL. The mass fraction of the sodium hydroxide solution is 10%.

[0074] The dosage ratio of intermediate 3, sodium periodate, tetrahydrofuran, deionized water and hydrochloric acid solution described in Step B2 is 5 mmol: 15 mmol: 40 mL: 10 mL: 3.5 mL. The mass fraction of the hydrochloric acid solution is 5%. The dosage ratio of intermediate 2, intermediate 4 and 5A molecular sieve is 10 mmol: 30 mmol: 2 g.

[0075] The molar ratio of intermediate 5, 2-aminoterephthalic acid and DOPO described in Step B3 is 1:3:3. The dosage ratio of the organic ligand, samarium nitrate hexahydrate, N,N-dimethylformamide and deionized water is 1.5 mmol: 1 mmol: 50 mL: 5 mL.

[0076] Comparative Example 1

[0077] In this comparative example, no modified monomer was added compared with Example 1, and the other steps were the same.

[0078] Comparative Example 2

[0079] In this comparative example, compared with Example 1, diamine-terminated polysiloxane was used to replace the modified monomer, and the remaining steps were the same.

[0080] Comparative Example 3

[0081] In this comparative example, compared with Example 1, modified filler was used to replace the functional filler, and the remaining steps were the same.

[0082] Comparative Example 4

[0083] In this comparative example, compared with Example 1, intermediate 5 was not added, and the remaining steps were the same.

[0084] The colored spun yarns prepared in Examples 1-3 and Comparative Examples 1-4 were made into specimens under Condition A according to the standard of GB / T5455-2014, and the afterflame time, smoldering time and damage length were detected. The detection results are shown in the following table.

[0085]

[0086] It can be seen from the above table that this application has a good flame retardant effect.

[0087] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. A method for preparing a flame-retardant composite color-spun yarn, characterized in that: Specifically, it includes the following steps: Step S1: Mix and stir the modified filler, 3-isocyanatopropylmethyldimethoxysilane, and toluene to obtain a functional filler. Mix and stir 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, a modified monomer, and N,N-dimethylacetamide, and add the functional filler to obtain a spinning solution. Step S2: Keep at a high temperature to obtain reinforced fibers. Dye the reinforced fibers respectively to obtain dyed fibers. Perform the processes of opening, carding, drawing, roving, and spinning on the dyed fibers to obtain a pretreated yarn. Immerse the pretreated yarn in deionized water, take it out and dry it to obtain a flame-retardant composite colored spun yarn. The modified monomer is prepared by the following steps: Step A1: Mix and react phosphorus oxychloride, 2,2-dimethylolpropionic acid, and N,N-dimethylformamide to obtain Intermediate 1. Dissolve Intermediate 1 in N,N-dimethylformamide, protect it by introducing nitrogen, stir and add formic acid at a rotation speed of 150 - 200 r / min and a temperature of 30 - 40 °C, and react for 4 - 6 h to obtain a phosphorus additive. Mix the phosphorus additive, KH550, dicyclohexylcarbodiimide, and N,N-dimethylformamide, and react at a rotation speed of 120 - 150 r / min and a temperature of 30 - 40 °C for 3 - 5 h to obtain a phosphorus modifier. Step A2: Mix octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, tetramethylammonium hydroxide, and dimethyl sulfoxide evenly, protect it by introducing nitrogen, and react at a rotation speed of 120 - 150 r / min and a temperature of 90 - 100 °C for 3 - 5 h to obtain a diamine-terminated polysiloxane. Mix the diamine-terminated polysiloxane, the phosphorus modifier, and N,N-dimethylformamide evenly, protect it by introducing nitrogen, and react at a rotation speed of 150 - 200 r / min and a temperature of 65 - 70 °C for 40 - 45 h to obtain a modified monomer. The modified filler is prepared by the following steps: Step B1: Mix and stir melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve, and methanol, and add hydrochloric acid solution, then raise the temperature for reaction to obtain Intermediate 2. After mixing and reacting 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl etherate, and N,N-dimethylformamide, add sodium hydroxide solution and raise the temperature for reaction to obtain Intermediate 3. Step B2: Mix Intermediate 3, sodium periodate, tetrahydrofuran, and deionized water, stir and add hydrochloric acid solution, and react to obtain Intermediate 4. Mix and react Intermediate 2, Intermediate 4, 5A molecular sieve, and N,N-dimethylformamide to obtain Intermediate 5. Step B3: After mixing intermediate 5, 2-aminoterephthalic acid and N,N-dimethylformamide for reaction, adjust the pH to acidic, raise the temperature and add DOPO, and continue the reaction to obtain an organic ligand. Mix the organic ligand, samarium nitrate hexahydrate and N,N-dimethylformamide, stir and add deionized water, and carry out the reaction to obtain a modified filler.

2. The preparation method of a flame-retardant composite color-spun yarn according to claim 1, characterized in that: The dosage ratio of the modified filler described in Step S1 to 3-isocyanatopropylmethyldimethoxysilane is 1 g: 3 mL, and the dosage ratio of 3,3',4,4'-biphenyltetracarboxylic dianhydride, p-phenylenediamine, modified monomer, N,N-dimethylacetamide and functional filler is 55 mmol: 40 mmol: 15 mmol: 60 mL: 5 g.

3. The preparation method of a flame-retardant composite color spinning yarn according to claim 1, characterized in that: The molar ratio of phosphorus oxychloride to 2,2-dimethylolpropionic acid described in Step A1 is 1:1, the molar ratio of intermediate 1 to formic acid is 1:1, and the molar ratio of phosphorus additive, KH550 and dicyclohexylcarbodiimide is 1:1:1.

1.

4. The preparation method of a flame-retardant composite color-spun yarn according to claim 1, wherein: The molar ratio of octamethylcyclotetrasiloxane, 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane and tetramethylammonium hydroxide described in Step A2 is 1.8:0.6:2:3, and the molar ratio of the double bond on the diamine-terminated polysiloxane to the phosphorus modifier is 1:

1.

5. The preparation method of a flame-retardant composite color-spun yarn according to claim 1, characterized in that: The dosage ratio of melamine, 3,4-dihydroxybenzaldehyde, 4A molecular sieve and hydrochloric acid solution described in Step B1 is 50 mmol: 150 mmol: 1 g: 2 mL, and the dosage ratio of 4-hydroxyphenylboronic acid pinacol ester, epichlorohydrin, boron trifluoride diethyl ether and sodium hydroxide solution is 10 mmol: 10 mmol: 0.5 g: 30 mL.

6. The preparation method of a flame-retardant composite color-spun yarn according to claim 1, characterized in that: The dosage ratio of intermediate 3, sodium periodate, tetrahydrofuran, deionized water and hydrochloric acid solution described in Step B2 is 5 mmol: 15 mmol: 40 mL: 10 mL: 3.5 mL, and the dosage ratio of intermediate 2, intermediate 4 and 5A molecular sieve is 10 mmol: 30 mmol: 2 g.

7. The preparation method of a flame-retardant composite color-spun yarn according to claim 1, characterized in that: The molar ratio of intermediate 5, 2-aminoterephthalic acid and DOPO described in Step B3 is 1:3:3, and the dosage ratio of the organic ligand, samarium nitrate hexahydrate, N,N-dimethylformamide and deionized water is 1.5 mmol: 1 mmol: 50 mL: 5 mL.

8. A flame-retardant composite colored spun yarn, characterized in that: Prepared by the preparation method according to any one of Claims 1-7.

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