A flame retardant used in flame retardant fabric and a preparation method thereof

Abstract

The invention relates to the technical field of flame retardants, and discloses a flame retardant applied to flame retardant cloth and a preparation method thereof; the invention adds silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, sulfur-modified imidazole, bisphenol A epoxy resin, and diethylenetriamine into a reactor, and stirs to obtain a flame retardant applied to flame retardant cloth. The flame retardant of the flame retardant cloth contains phosphorus, silicon, sulfur, and boron flame retardant elements; and imidazole and quaternary ammonium salt antibacterial groups; during the stirring process, the imidazole group will synergistically act with the diethylenetriamine to cure the epoxy resin, forming a cross-linked network between each other to improve its viscosity.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardants, in particular to a flame retardant applied to flame retardant cloth and a preparation method thereof. Background Art

[0002] Flame retardant science and technology is a science developed to meet the needs of social safety production and life, prevent fires, and protect people's lives and property. Flame retardant is the application of flame retardant technology in real life. It is a special chemical additive used to improve the combustion performance of combustible and flammable materials. It is widely used in the flame retardant processing of various types of decoration materials. It has good heat resistance, water solubility and stability, but its own antibacterial properties are poor, which limits its development. Therefore, how to avoid this phenomenon is the key to solving the problem. For example, patent CN113278200B discloses a phosphorus-containing flame retardant and its preparation method and use. The invention obtains a flame retardant by reacting 3-hydroxyphenylphosphoryl propionic acid and amine, which only meets the requirements of good water solubility and thermal stability, but its own antibacterial effect and viscosity are not improved. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies of the prior art, the present invention provides a flame retardant applied to flame retardant cloth and a preparation method thereof, which has good flame retardant and antibacterial effects and excellent viscosity.

[0005] (II) Technical solution

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a flame retardant applied to flame-retardant cloth, comprising the following components by weight: 6-8 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 7-15 parts by weight of sulfur-containing modified imidazole, 10-12 parts by weight of bisphenol A epoxy resin, and 1-2 parts by weight of diethylenetriamine.

[0007] Preferably, the preparation method of the silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazolium hypophosphite is:

[0008] (1) Add N-methylimidazole and 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 80-100° C. for 8-12 hours to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0009] (2) Add 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to the ethanol solvent, stir and mix evenly, add anhydrous sodium hypophosphite reaction system, react at 68-80°C for 4-6 hours, and prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite.

[0010] Preferably, the mass ratio of N-methylimidazole to 3-chloropropyltriethoxysilane in (1) is 1:1.2-1.4.

[0011] Preferably, the mass ratio of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to anhydrous sodium hypophosphite in (2) is 1.4-1.6:1.

[0012] Preferably, the preparation method of the sulfur-containing modified imidazole is:

[0013] S1. Add N-methylimidazole and 3-chloropropylene to N,N-dimethylformamide solvent, react at 75-90°C for 5-8h, and then distill under reduced pressure, wash and dry to obtain intermediate 1;

[0014] S2. Add intermediate 1 to methanol solvent, stir and disperse, then add mercaptoethylamine and benzoin dimethyl ether photoinitiator, irradiate with 365nm ultraviolet light at 35-45°C for 1.2-3.5h, centrifuge, wash and dry to obtain intermediate 2;

[0015] S3. Add intermediate 2 and boric acid to N,N-dimethylformamide solvent, mix thoroughly, react at 68-72°C for 4.5-6h, wash and dry, purify by chromatography, and obtain sulfur-containing modified imidazole.

[0016] Preferably, the mass ratio of the N,N-dimethylformamide solvent to N-methylimidazole and 3-chloropropylene in S1 is 1:1.3-1.7.

[0017] Preferably, the mass ratio of the intermediate 1, mercaptoethylamine and benzoin dimethyl ether photoinitiator in S2 is 1.1-1.25:1:0.2-0.25.

[0018] Preferably, the mass ratio of intermediate 2 to boric acid in S3 is 1:0.8-1.2.

[0019] Preferably, the preparation method of the flame retardant applied to flame retardant cloth is: adding silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, sulfur-modified imidazole, bisphenol A type epoxy resin, and diethylenetriamine into a reactor, stirring for 10-15 minutes, and obtaining the flame retardant applied to flame retardant cloth.

[0020] 3. Beneficial technical effects

[0021] The invention adds silicon ion liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, sulfur-containing modified imidazole, bisphenol A type epoxy resin and diethylenetriamine into a reactor and stirs the mixture to obtain a flame retardant for flame retardant cloth.

[0022] The flame retardant of flame retardant cloth contains phosphorus, silicon, sulfur, boron flame retardant elements; and imidazole, quaternary ammonium salt antibacterial groups; the silicon element contained in it can form a glass-like substance on the surface of the material when burning, which hinders the material transfer and energy transport between the air and the substrate; the phosphorus element contained in it can generate polyphosphoric acid and metaphosphoric acid with strong dehydration properties, so that the material is dehydrated and carbonized. Since polyphosphoric acid and metaphosphoric acid are not easy to volatilize, they can form a dense protective layer on the surface of the polymer, which can not only isolate the contact between oxygen and the material, but also hinder the transfer of heat. When sulfur burns, it can accelerate the carbonization of the material and promote the formation of a dense carbon layer on the surface of the material, which has a flame retardant effect. Boron reacts with oxygen at high temperature to generate boric acid. Boric acid is a non-combustible substance that can dilute the oxygen concentration in the flame and reduce the combustion intensity of the flame. Boron and phosphorus work together in the condensed phase to form a more stable and continuous carbon layer, increase the residual carbon rate of the material, and enhance the heat insulation and oxygen isolation effects. During the stirring process, the imidazole group will synergistically work with diethylenetriamine to cure the epoxy resin, forming a cross-linked network between each other to increase its viscosity. DETAILED DESCRIPTION

[0023] Example 1

[0024] (1) Add 5 g of N-methylimidazole and 6 g of 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 80° C. for 8 h to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0025] (2) Add 2.8 g of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to 50 ml of ethanol solvent, stir and mix evenly, add 2 g of anhydrous sodium hypophosphite, react at 68 ° C for 4 h, and prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite;

[0026] (3) Add 4 g of N-methylimidazole and 5.2 g of 3-chloropropylene to 90 ml of N,N-dimethylformamide solvent, and react at 75 °C for 5 h. After reaction, distill under reduced pressure, wash and dry to obtain intermediate 1.

[0027] (4) Add 3.3 g of intermediate 1 to 60 ml of methanol solvent, stir and disperse, then add 3 g of mercaptoethylamine and 0.6 g of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 35 ° C for 1.2 h, centrifuge, wash and dry to obtain intermediate 2;

[0028] (5) Add 2.5 g of intermediate 2 and 2 g of boric acid to 75 ml of N,N-dimethylformamide solvent, mix thoroughly, and react at 68 °C for 4.5 h. After reaction, wash, dry, and chromatographically purify to obtain sulfur-containing modified imidazole;

[0029] (6) 6 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 7 parts by weight of sulfur-modified imidazole, 10 parts by weight of bisphenol A epoxy resin, and 1 part by weight of diethylenetriamine were added into a reactor and stirred for 10 minutes to obtain a flame retardant for flame retardant cloth.

[0030] Example 2

[0031] (1) Add 5 g of N-methylimidazole and 7 g of 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 100° C. for 12 h to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0032] (2) Add 3.2 g of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to 80 ml of ethanol solvent, stir and mix evenly, add 2 g of anhydrous sodium hypophosphite, and react at 80° C. for 6 h to prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite;

[0033] (3) Add 4 g of N-methylimidazole and 6.8 g of 3-chloropropylene to 100 ml of N,N-dimethylformamide solvent, react at 90 °C for 8 h, and then distill under reduced pressure, wash and dry to obtain intermediate 1;

[0034] (4) Add 3.75 g of intermediate 1 to 80 ml of methanol solvent, stir and disperse, then add 3 g of mercaptoethylamine and 0.75 g of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 45 ° C for 3.5 h, centrifuge, wash and dry to obtain intermediate 2;

[0035] (5) Add 2.5 g of intermediate 2 and 3 g of boric acid to 85 ml of N,N-dimethylformamide solvent, mix thoroughly, and react at 72 °C for 6 h. After reaction, wash, dry, and purify by chromatography to obtain sulfur-containing modified imidazole;

[0036] (6) 8 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 15 parts by weight of sulfur-modified imidazole, 12 parts by weight of bisphenol A epoxy resin, and 2 parts by weight of diethylenetriamine were added into a reactor and stirred for 15 minutes to obtain a flame retardant for flame retardant cloth.

[0037] Example 3

[0038] (1) Add 5 g of N-methylimidazole and 6.5 g of 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 90° C. for 8 h to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0039] (2) Add 3 g of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to 65 ml of ethanol solvent, stir and mix evenly, add 2 g of anhydrous sodium hypophosphite, and react at 74 ° C for 5 h to prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite;

[0040] (3) Add 4 g of N-methylimidazole and 6 g of 3-chloropropylene to 95 ml of N,N-dimethylformamide solvent, and react at 82 °C for 6.5 h. After reaction, distill under reduced pressure, wash and dry to obtain intermediate 1.

[0041] (4) Add 3.5 g of intermediate 1 to 70 ml of methanol solvent, stir and disperse, then add 3 g of mercaptoethylamine and 0.67 g of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 40 ° C for 2.3 h, centrifuge, wash and dry to obtain intermediate 2;

[0042] (5) Add 2.5 g of intermediate 2 and 2.5 g of boric acid to 80 ml of N,N-dimethylformamide solvent, mix thoroughly, and react at 70 °C for 5.2 h. After reaction, wash, dry, and purify by chromatography to obtain sulfur-containing modified imidazole;

[0043] (6) 7 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 11 parts by weight of sulfur-modified imidazole, 11 parts by weight of bisphenol A epoxy resin, and 1.5 parts by weight of diethylenetriamine were added into a reactor and stirred for 12.5 minutes to obtain a flame retardant for flame retardant cloth.

[0044] Example 4

[0045] (1) Add 5 g of N-methylimidazole and 6 g of 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 80° C. for 8 h to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0046] (2) Add 2.8 g of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to 50 ml of ethanol solvent, stir and mix evenly, add 2 g of anhydrous sodium hypophosphite, react at 68 ° C for 4 h, and prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite;

[0047] (3) Add 4 g of N-methylimidazole and 6.8 g of 3-chloropropylene to 100 ml of N,N-dimethylformamide solvent, react at 90 °C for 8 h, and then distill under reduced pressure, wash and dry to obtain intermediate 1;

[0048] (4) Add 3.75 g of intermediate 1 to 80 ml of methanol solvent, stir and disperse, then add 3 g of mercaptoethylamine and 0.75 g of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 45 ° C for 3.5 h, centrifuge, wash and dry to obtain intermediate 2;

[0049] (5) Add 2.5 g of intermediate 2 and 2.5 g of boric acid to 80 ml of N,N-dimethylformamide solvent, mix thoroughly, and react at 70 °C for 5.2 h. After reaction, wash, dry, and purify by chromatography to obtain sulfur-containing modified imidazole;

[0050] (6) 7 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 11 parts by weight of sulfur-modified imidazole, 11 parts by weight of bisphenol A epoxy resin, and 1.5 parts by weight of diethylenetriamine were added into a reactor and stirred for 12.5 minutes to obtain a flame retardant for flame retardant cloth.

[0051] Example 5

[0052] (1) Add 5 g of N-methylimidazole and 7 g of 3-chloropropyltriethoxysilane into a reactor, introduce nitrogen protection, and react at 100° C. for 12 h to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride;

[0053] (2) Add 3.2 g of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to 80 ml of ethanol solvent, stir and mix evenly, add 2 g of anhydrous sodium hypophosphite, and react at 80° C. for 6 h to prepare silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite;

[0054] (3) Add 4 g of N-methylimidazole and 6 g of 3-chloropropylene to 95 ml of N,N-dimethylformamide solvent, and react at 82 °C for 6.5 h. After reaction, distill under reduced pressure, wash and dry to obtain intermediate 1.

[0055] (4) Add 3.5 g of intermediate 1 to 70 ml of methanol solvent, stir and disperse, then add 3 g of mercaptoethylamine and 0.67 g of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 40 ° C for 2.3 h, centrifuge, wash and dry to obtain intermediate 2;

[0056] (5) Add 2.5 g of intermediate 2 and 2 g of boric acid to 75 ml of N,N-dimethylformamide solvent, mix thoroughly, and react at 68 °C for 4.5 h. After reaction, wash, dry, and chromatographically purify to obtain sulfur-containing modified imidazole;

[0057] (6) 6 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 7 parts by weight of sulfur-modified imidazole, 10 parts by weight of bisphenol A epoxy resin, and 1 part by weight of diethylenetriamine were added into a reactor and stirred for 10 minutes to obtain a flame retardant for flame retardant cloth.

[0058] Comparative Example 1

[0059] The difference between this comparative example and Example 5 is that the silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazolium hypophosphite is not added.

[0060] Comparative Example 2

[0061] Compared with Example 5, this comparative example is characterized in that no sulfur-containing modified imidazole is added.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 5 is that no bisphenol A epoxy resin is added.

[0064] The limiting oxygen index of the material was tested using an oxygen index meter, and the combustion grade of the material was tested using a horizontal and vertical combustion instrument. The test results are shown in Table 1.

[0065] Table 1: Flame retardancy tests.

[0066]

[0067] As can be seen from Table 1, Examples 1-5 and Comparative Example 3 of the present invention have better flame retardant effects than Comparative Examples 1 and 2; because Examples 1-5 and Comparative Example 3 contain flame retardant systems such as silicon, phosphorus, sulfur, and boron, but Comparative Example 1 only contains sulfur and boron, and Comparative Example 2 only contains silicon and phosphorus, so the flame retardant effect is poor.

[0068] Using Staphylococcus aureus, Escherichia coli or Candida albicans as the test bacteria, 0.5 mL of the bacterial suspension of the test bacteria (concentration of 1×106 CFU / mL) was added to a sterile culture dish containing beef extract peptone medium, and then the flame retardant sample applied to the flame retardant cloth was attached to the surface of the culture medium, and cultured in a constant temperature incubator at 37°C for 24 hours. After culture, the diameter of the inhibition zone was measured.

[0069] Table 2: Antimicrobial testing.

[0070]

[0071] It can be seen from Table 2 that Examples 1-5 and Comparative Example 3 of the present invention have better antibacterial effects than Comparative Examples 1 and 2.

[0072] The viscosity test was carried out using a NDJ-8S digital viscometer at room temperature. The test standard was GB / T22235-2008. The test results are shown in Table 3.

[0073] Table 3: Adhesion testing.

[0074]

[0075] As can be seen from Table 3, Examples 1-5 and Comparative Examples 1-2 of the present invention have better viscosity than Comparative Example 3, because Examples 1-5 and Comparative Example 1-2 contain imidazole groups that will cooperate with diethylenetriamine and epoxy resin to cure to form a cross-linked network, thereby increasing its viscosity. Comparative Example 3 does not contain epoxy resin, so its viscosity is poor.

[0076] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flame retardant for flame retardant fabric, characterized in that: The invention comprises the following components by weight: 6-8 parts by weight of silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, 7-15 parts by weight of sulfur-modified imidazole, 10-12 parts by weight of bisphenol A epoxy resin, and 1-2 parts by weight of diethylenetriamine; The preparation method of the silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazolium hypophosphite is as follows: (1) adding N-methylimidazole and 3-chloropropyltriethoxysilane into a reactor, introducing nitrogen protection, and reacting at 80-100° C. for 8-12 hours to obtain 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride; (2) adding 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to an ethanol solvent, stirring and mixing evenly, adding anhydrous sodium hypophosphite reaction system, reacting at 68-80° C. for 4-6 hours, and preparing silicon-containing ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite; The mass ratio of N-methylimidazole to 3-chloropropyltriethoxysilane in (1) is 1:1.2-1.4; The mass ratio of 1-(3-triethoxysilylpropyl)-3-methylimidazole chloride to anhydrous sodium hypophosphite in (2) is 1.4-1.6:1; The preparation method of the sulfur-containing modified imidazole is: S1. Add N-methylimidazole and 3-chloropropylene to N,N-dimethylformamide solvent, react at 75-90°C for 5-8h, and then distill under reduced pressure, wash and dry to obtain intermediate 1; S2. Add intermediate 1 to methanol solvent, stir and disperse, then add mercaptoethylamine and benzoin dimethyl ether photoinitiator, irradiate with 365nm ultraviolet light at 35-45°C for 1.2-3.5h, centrifuge, wash and dry to obtain intermediate 2; S3. Add intermediate 2 and boric acid to N,N-dimethylformamide solvent, mix thoroughly, react at 68-72°C for 4.5-6h, wash and dry, purify by chromatography, and obtain sulfur-containing modified imidazole; The mass ratio of N-methylimidazole to 3-chloropropylene in S1 is 1:1.3-1.7; The mass ratio of intermediate 1, mercaptoethylamine and benzoin dimethyl ether photoinitiator in S2 is 1.1-1.25:1:0.2-0.25; The mass ratio of the intermediate 2 to the boric acid in S3 is 1:0.8-1.

2.

2. A method for preparing a flame retardant for flame retardant cloth according to claim 1, characterized in that: The preparation method of the flame retardant applied to flame retardant cloth is as follows: silicon ionic liquid 1-(3-triethoxysilylpropyl)-3-methylimidazole hypophosphite, sulfur-containing modified imidazole, bisphenol A type epoxy resin, and diethylenetriamine are added into a reactor, and stirred for 10-15 minutes to obtain the flame retardant applied to flame retardant cloth.

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