Silica sol modified emulsion and preparation method thereof

Abstract

The invention relates to the technical field of silica sol, and discloses a silica sol modified emulsion and a preparation method thereof.The preparation method comprises the steps that silica sol, an emulsifier SR-10, thiazole modified benzoxazine, sodium sulfonate modified thiazole and water are added into a reactor and stirred, and the silica sol modified emulsion is obtained after stirring is finished. Sulfur elements, nitrogen elements, silicon elements, benzoxazine structures and sodium sulfonate groups contained in thiazole modified benzoxazine and sodium sulfonate modified thiazole have good flame retardance; quaternary ammonium salts contained in thiazole modified benzoxazine and sodium sulfonate modified thiazole are adsorbed to the surfaces of thalli, and hydrophobic groups are inserted into lipoid layers, so that the permeability of cell membranes is changed, the membrane structure is destroyed, intracellular substances are leaked, bacterial death is caused, and a relatively good antibacterial effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of silica sol, in particular to a silica sol modified emulsion and a preparation method thereof. Background Art

[0002] The main component of silica sol is silicon dioxide (SiO2). Silica sol is a colloidal solution, odorless and non-toxic. Its colloidal particles are fine (10-20nm) and have a large specific surface area. The particles themselves are colorless and transparent and do not affect the original color of the covered object. However, its flame retardant and antibacterial effects are poor, which greatly limits its application and affects its use in many fields. For example, patent CN104961134B discloses silica sol and its preparation method. The silica sol of this invention has high purity and high stability, but its flame retardant and antibacterial properties have not been improved. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a silica sol modified emulsion and a preparation method thereof, which has good flame retardant and antibacterial effects.

[0004] (II) Technical solution To achieve the above-mentioned object, the present invention provides the following technical scheme: a silica sol-modified emulsion, comprising the following components by weight: 40-60 parts by weight of silica sol, 1-3 parts by weight of emulsifier SR-10, 5-10 parts by weight of thiazole-modified benzoxazine, 6-8 parts by weight of sodium sulfonate-modified thiazole, and 14-20 parts by weight of water.

[0005] The preparation method of the thiazole-modified benzoxazine is: (1) Add 5-aminoisophthalic acid and thionyl chloride to xylene solvent, stir evenly, heat to 75-90°C, react for 3-6 hours, and then remove the solvent by evaporation under reduced pressure to obtain intermediate 1; (2) Add 2-aminothiazole to an acetone solvent, then add the intermediate 1 and triethylamine catalyst, stir and mix, react at 80-100° C. for 6-12 hours, and after completion, cool to room temperature, filter, and wash to obtain a modified thiazole; (3) Add vinyl chloride and modified thiazole to N,N-dimethylformamide solvent, stir evenly, react at 70-95°C for 6-8h, and then distill under reduced pressure, wash and dry to obtain olefinated thiazole; (4) Add olefinated thiazole to N,N-dimethylamide solvent, stir and disperse, then add benzoin dimethyl ether photoinitiator and 1,3-propanedithiol, irradiate with 365 nm ultraviolet light at 20-40° C. for 2-4 h, centrifuge, wash with deionized water, and dry to obtain intermediate 2; (5) The intermediate 2, the aqueous solution of formaldehyde and phenol are added to a toluene solvent and fully dissolved to carry out a cyclization reaction at 65-90°C for 10-16 hours. After the reaction, the product is distilled under reduced pressure, washed with deionized water, and the crude product is recrystallized from dichloromethane to obtain a thiazole-modified benzoxazine.

[0006] The mass ratio of 5-aminoisophthalic acid to thionyl chloride in (1) is 1:2.2-2.6.

[0007] The mass ratio of 2-aminothiazole, intermediate 1 and triethylamine catalyst in (2) is 1.2-1.4:1:0.01-0.03.

[0008] The mass ratio of vinyl chloride to modified thiazole in (3) is 2.4-2.8:1.

[0009] The mass ratio of olefinated thiazole, benzoin dimethyl ether photoinitiator and 1,3-propanedithiol in (4) is 1:0.01-0.03:1.1-1.5.

[0010] The mass ratio of the intermediate 2, the aqueous solution of formaldehyde and the phenol in (5) is 1:1.3-1.4:1.2-1.5.

[0011] The preparation method of the sodium sulfonate modified thiazole is: S1. Under a nitrogen atmosphere, 5-12 parts by weight of olefinated thiazole and 0.1-0.2 parts by weight of chloroplatinic acid catalyst were added to a reactor containing tetrahydrofuran solvent, stirred evenly, and 1,1,3,3-tetramethyldisiloxane was added thereto, reacted at 65-80°C for 40-65min, cooled to room temperature after completion, and an activated carbon adsorbent was added to remove the catalyst to obtain a modified silane; S2. 10-16 parts by weight of modified silane and 18-25 parts by weight of 1,3-propane sultone are dissolved in 1,4-dioxane solvent, and then a sodium hydroxide solution with a mass fraction of 3-5% is added dropwise, and the temperature is raised to 60-80°C for reaction for 6-13 hours. After the reaction, the solvent is removed by concentration under reduced pressure, and the crude product is recrystallized in ethanol to obtain sodium sulfonate modified thiazole.

[0012] The preparation method of the silica sol modified emulsion is as follows: silica sol, emulsifier SR-10, thiazole modified benzoxazine, sodium sulfonate modified thiazole, and water are added into a reactor, and stirred for 10-15 minutes, and then the silica sol modified emulsion is obtained.

[0013] 3. Beneficial technical effects The invention adds silica sol, emulsifier SR-10, thiazole-modified benzoxazine, sodium sulfonate-modified thiazole and water into a reactor, and stirs to obtain silica sol-modified emulsion.

[0014] The sulfur, nitrogen, silicon, benzoxazine structure and sodium sulfonate groups contained in thiazole-modified benzoxazine and sodium sulfonate-modified thiazole all have good flame retardancy; the sulfur element generates strong acidic substances when heated, which can promote the dehydration of the substrate into carbon, and play a good flame retardant effect. The nitrogen element contained therein can generate non-flammable gas when heated, dilute the concentration of flammable gas, and achieve the purpose of flame retardancy. The silicon element contained therein has a large silicon-oxygen bond energy, which can not only absorb more heat, but also absorb heat to produce a glass-like substance, which covers the surface of the material, isolates material transportation and energy transfer, and the benzoxazine therein will form a heat-resistant phenolic resin structure at high temperature, so that it has a good flame retardant effect; the sodium sulfonate group can promote the release of carbon dioxide and water at high temperature, thereby playing a flame retardant effect, and 2-aminothiazole reacts with intermediate 1, further increasing the degree of substitution of sulfur and nitrogen elements, and improving its flame retardant effect. The quaternary ammonium salt contained in thiazole-modified benzoxazine and sodium sulfonate-modified thiazole is adsorbed to the surface of bacteria, and the hydrophobic group is inserted into the lipid layer, which changes the permeability of the cell membrane, destroys the membrane structure, causes the leakage of intracellular substances, leads to bacterial death, and has a good antibacterial effect. DETAILED DESCRIPTION Example 1

[0015] (1) Add 5-aminoisophthalic acid and thionyl chloride to xylene solvent, wherein the mass ratio of 5-aminoisophthalic acid to thionyl chloride is 1:2.2, stir evenly, heat to 75°C, react for 3 hours, and then remove the solvent under reduced pressure to obtain intermediate 1; (2) Add 2-aminothiazole to an acetone solvent, and then add intermediate 1 and triethylamine catalyst thereto, wherein the mass ratio of 2-aminothiazole, intermediate 1, and triethylamine catalyst is 1.2:1:0.01, stir and mix, react at 80°C for 6 hours, and after reaction, cool to room temperature, filter, and wash to obtain modified thiazole; (3) Adding vinyl chloride and modified thiazole to N,N-dimethylformamide solvent, wherein the mass ratio of vinyl chloride to modified thiazole is 2.4:1, stirring evenly, reacting at 70°C for 6 hours, and then distilling under reduced pressure, washing and drying to obtain olefinated thiazole; (4) Add olefinated thiazole to N,N-dimethylamide solvent, stir and disperse, then add benzoin dimethyl ether photoinitiator and 1,3-propylene glycol, wherein the mass ratio of olefinated thiazole, benzoin dimethyl ether photoinitiator and 1,3-propylene glycol is 1:0.01:1.1, irradiate with 365 nm ultraviolet light at 20°C for 2 h, centrifuge, wash with deionized water, and dry to obtain intermediate 2; (5) adding intermediate 2, an aqueous solution of formaldehyde, and phenol into toluene solvent, wherein the mass ratio of intermediate 2, aqueous solution of formaldehyde, and phenol is 1:1.3:1.2, fully dissolving, and carrying out cyclization reaction at 65°C for 10 hours. After completion, distillation under reduced pressure is carried out, and the product is washed with deionized water. The crude product is recrystallized from dichloromethane to obtain thiazole-modified benzoxazine; (6) Under a nitrogen atmosphere, 5 parts by weight of olefinated thiazole and 0.1 parts by weight of chloroplatinic acid catalyst were added to a reaction kettle containing tetrahydrofuran solvent, and the mixture was stirred evenly. 1,1,3,3-tetramethyldisiloxane was added thereto, and the mixture was reacted at 65° C. for 40 min. After the reaction was completed, the mixture was cooled to room temperature, and an activated carbon adsorbent was added to remove the catalyst to obtain modified silane; (7) 10 parts by weight of modified silane and 18 parts by weight of 1,3-propane sultone were dissolved in 1,4-dioxane solvent, and then a 3% by weight sodium hydroxide solution was added dropwise, and the temperature was raised to 60° C. to react for 6 h. After the reaction, the solvent was removed by concentration under reduced pressure, and the crude product was recrystallized in ethanol to obtain sodium sulfonate modified thiazole; (8) 40 parts by weight of silica sol, 1 part by weight of emulsifier SR-10, 5 parts by weight of thiazole-modified benzoxazine, 6 parts by weight of sodium sulfonate-modified thiazole, and 14 parts by weight of water were added into a reactor and stirred for 10 minutes to obtain a silica sol-modified emulsion. Example 2

[0016] (1) Add 5-aminoisophthalic acid and thionyl chloride to xylene solvent, wherein the mass ratio of 5-aminoisophthalic acid to thionyl chloride is 1:2.6, stir evenly, heat to 90°C, react for 6 hours, and then remove the solvent by evaporation under reduced pressure to obtain intermediate 1; (2) Add 2-aminothiazole to an acetone solvent, and then add intermediate 1 and triethylamine catalyst thereto, wherein the mass ratio of 2-aminothiazole, intermediate 1, and triethylamine catalyst is 1.4:1:0.03, stir and mix, react at 100° C. for 12 h, and after reaction, cool to room temperature, filter, and wash to obtain modified thiazole; (3) Adding vinyl chloride and modified thiazole to N,N-dimethylformamide solvent, wherein the mass ratio of vinyl chloride to modified thiazole is 2.8:1, stirring evenly, reacting at 95°C for 8 hours, and then distilling under reduced pressure, washing and drying to obtain olefinated thiazole; (4) Add olefinated thiazole to N,N-dimethylamide solvent, stir and disperse, then add benzoin dimethyl ether photoinitiator and 1,3-propylene glycol, wherein the mass ratio of olefinated thiazole, benzoin dimethyl ether photoinitiator and 1,3-propylene glycol is 1:0.03:1.5, irradiate with 365 nm ultraviolet light at 40°C for 4 h, centrifuge, wash with deionized water, and dry to obtain intermediate 2; (5) adding intermediate 2, an aqueous solution of formaldehyde and phenol into toluene solvent, wherein the mass ratio of intermediate 2, aqueous solution of formaldehyde and phenol is 1:1.4:1.5, fully dissolving, and carrying out cyclization reaction at 90°C for 16 hours. After completion, distillation under reduced pressure is carried out, and the product is washed with deionized water. The crude product is recrystallized from dichloromethane to obtain thiazole-modified benzoxazine; (6) Under a nitrogen atmosphere, 12 parts by weight of olefinated thiazole and 0.2 parts by weight of chloroplatinic acid catalyst were added to a reaction kettle containing tetrahydrofuran solvent, and the mixture was stirred evenly. 1,1,3,3-tetramethyldisiloxane was added thereto, and the mixture was reacted at 80° C. for 65 min. After the reaction was completed, the mixture was cooled to room temperature, and an activated carbon adsorbent was added to remove the catalyst to obtain modified silane; (7) 16 parts by weight of modified silane and 25 parts by weight of 1,3-propane sultone were dissolved in 1,4-dioxane solvent, and then a 5% by weight sodium hydroxide solution was added dropwise, and the temperature was raised to 80° C. to react for 13 h. After the reaction, the solvent was removed by concentration under reduced pressure, and the crude product was recrystallized in ethanol to obtain sodium sulfonate modified thiazole; (8) 60 parts by weight of silica sol, 3 parts by weight of emulsifier SR-10, 10 parts by weight of thiazole-modified benzoxazine, 8 parts by weight of sodium sulfonate-modified thiazole, and 20 parts by weight of water were added into a reactor and stirred for 15 minutes to obtain a silica sol-modified emulsion. Example 3

[0017] (1) Add 5-aminoisophthalic acid and thionyl chloride to xylene solvent, wherein the mass ratio of 5-aminoisophthalic acid to thionyl chloride is 1:2.4, stir evenly, heat to 80°C, react for 4 hours, and then remove the solvent by vacuum evaporation to obtain intermediate 1; (2) Add 2-aminothiazole to an acetone solvent, and then add intermediate 1 and triethylamine catalyst thereto, wherein the mass ratio of 2-aminothiazole, intermediate 1, and triethylamine catalyst is 1.2-1.4:1:0.01-0.03, stir and mix, react at 90° C. for 9 h, and after reaction, cool to room temperature, filter, and wash to obtain modified thiazole; (3) Adding vinyl chloride and modified thiazole to N,N-dimethylformamide solvent, wherein the mass ratio of vinyl chloride to modified thiazole is 2.6:1, stirring evenly, reacting at 82°C for 7 hours, and then distilling under reduced pressure, washing and drying to obtain olefinated thiazole; (4) Add olefinated thiazole to N,N-dimethylamide solvent, stir and disperse, then add benzoin dimethyl ether photoinitiator and 1,3-propylene glycol, wherein the mass ratio of olefinated thiazole, benzoin dimethyl ether photoinitiator and 1,3-propylene glycol is 1:0.02:1.3, irradiate with 365 nm ultraviolet light at 30°C for 3 h, centrifuge, wash with deionized water, and dry to obtain intermediate 2; (5) adding intermediate 2, an aqueous solution of formaldehyde and phenol into toluene solvent, wherein the mass ratio of intermediate 2, aqueous solution of formaldehyde and phenol is 1:1.35:1.4, fully dissolving, and carrying out cyclization reaction at 80°C for 13 hours. After completion, distillation under reduced pressure is carried out, and the crude product is washed with deionized water and recrystallized from dichloromethane to obtain thiazole-modified benzoxazine; (6) Under a nitrogen atmosphere, 8 parts by weight of olefinated thiazole and 0.15 parts by weight of chloroplatinic acid catalyst were added to a reaction kettle containing tetrahydrofuran solvent, and the mixture was stirred evenly. 1,1,3,3-tetramethyldisiloxane was added thereto, and the mixture was reacted at 74° C. for 53 min. After the reaction was completed, the mixture was cooled to room temperature, and an activated carbon adsorbent was added to remove the catalyst to obtain modified silane; (7) 13 parts by weight of modified silane and 22 parts by weight of 1,3-propane sultone were dissolved in 1,4-dioxane solvent, and then a 4% by weight sodium hydroxide solution was added dropwise, and the temperature was raised to 70° C. to react for 10 h. After the reaction, the solvent was removed by concentration under reduced pressure, and the crude product was recrystallized in ethanol to obtain sodium sulfonate modified thiazole; (8) 50 parts by weight of silica sol, 2 parts by weight of emulsifier SR-10, 7 parts by weight of thiazole-modified benzoxazine, 7 parts by weight of sodium sulfonate-modified thiazole, and 16 parts by weight of water were added into a reactor and stirred for 12.5 minutes to obtain a silica sol-modified emulsion.

[0018] Comparative Example 1 Compared with Example 3, this comparative example does not add thiazole-modified benzoxazine.

[0019] Comparative Example 2 Compared with Example 3, this comparative example does not add sodium sulfonate to modify the thiazole.

[0020] The oxygen index of the silica sol modified emulsion was tested using an oxygen index tester, and the combustion grade of the silica sol modified emulsion was tested using a horizontal and vertical combustion tester.

[0021] Table 1: Flame retardancy tests.

[0022] project Oxygen index (%) UL-94 Example 1 32 V-0 Example 2 33 V-0 Example 3 31 V-0 Comparative Example 1 20 V-1 Comparative Example 2 21 V-1 It can be seen from Table 1 that Examples 1-3 of the present invention have better flame retardant effects than Comparative Examples 1-2.

[0023] With Staphylococcus aureus, Escherichia coli, and Candida albicans as the test bacteria, a bacterial suspension with a concentration of 1×105 CFU / mL was prepared, 1.2 mL of the bacterial suspension was transferred to a sterilized culture dish containing MH broth medium, and then the silica sol modified latex sample was attached to the surface of the culture medium, and cultured at 42°C for 15 hours in a constant temperature incubator, and the diameter of the inhibition zone was measured after culture. The test results are shown in Table 1.

[0024] Table 2: Antimicrobial testing.

[0025]

[0026] It can be seen from Table 2 that Examples 1-3 of the present invention have better antibacterial effects than Comparative Examples 1-2.

[0027] 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 silica sol modified emulsion, characterized in that: The invention comprises the following components by weight: 40-60 parts by weight of silica sol, 1-3 parts by weight of emulsifier SR-10, 5-10 parts by weight of thiazole-modified benzoxazine, 6-8 parts by weight of sodium sulfonate-modified thiazole, and 14-20 parts by weight of water.

2. The silica sol modified emulsion according to claim 1, characterized in that: The preparation method of the thiazole-modified benzoxazine is: (1) Add 5-aminoisophthalic acid and thionyl chloride to xylene solvent, stir evenly, heat to 75-90°C, react for 3-6 hours, and then remove the solvent by evaporation under reduced pressure to obtain intermediate 1; (2) Add 2-aminothiazole to an acetone solvent, then add the intermediate 1 and triethylamine catalyst, stir and mix, react at 80-100° C. for 6-12 hours, and after completion, cool to room temperature, filter, and wash to obtain a modified thiazole; (3) Add vinyl chloride and modified thiazole to N,N-dimethylformamide solvent, stir evenly, react at 70-95°C for 6-8h, and then distill under reduced pressure, wash and dry to obtain olefinated thiazole; (4) Add olefinated thiazole to N,N-dimethylamide solvent, stir and disperse, then add benzoin dimethyl ether photoinitiator and 1,3-propanedithiol, irradiate with 365 nm ultraviolet light at 20-40° C. for 2-4 h, centrifuge, wash with deionized water, and dry to obtain intermediate 2; (5) The intermediate 2, the aqueous solution of formaldehyde and phenol are added to a toluene solvent and fully dissolved to carry out a cyclization reaction at 65-90°C for 10-16 hours. After the reaction, the product is distilled under reduced pressure, washed with deionized water, and the crude product is recrystallized from dichloromethane to obtain a thiazole-modified benzoxazine.

3. The silica sol modified emulsion according to claim 2, characterized in that: The mass ratio of 5-aminoisophthalic acid to thionyl chloride in (1) is 1:2.2-2.

6.

4. The silica sol modified emulsion according to claim 2, characterized in that: The mass ratio of 2-aminothiazole, intermediate 1 and triethylamine catalyst in (2) is 1.2-1.4:1:0.01-0.

03.

5. The silica sol modified emulsion according to claim 2, characterized in that: The mass ratio of vinyl chloride to modified thiazole in (3) is 2.4-2.8:

1.

6. The silica sol modified emulsion according to claim 2, characterized in that: The mass ratio of olefinated thiazole, benzoin dimethyl ether photoinitiator and 1,3-propanedithiol in (4) is 1:0.01-0.03:1.1-1.

5.

7. The silica sol modified emulsion according to claim 2, characterized in that: The mass ratio of the intermediate 2, the aqueous solution of formaldehyde and the phenol in (5) is 1:1.3-1.4:1.2-1.

5.

8. The silica sol modified emulsion according to claim 1, characterized in that: The preparation method of the sodium sulfonate modified thiazole is: S1. Under a nitrogen atmosphere, 5-12 parts by weight of olefinated thiazole and 0.1-0.2 parts by weight of chloroplatinic acid catalyst were added to a reactor containing tetrahydrofuran solvent, stirred evenly, and 1,1,3,3-tetramethyldisiloxane was added thereto, reacted at 65-80°C for 40-65min, cooled to room temperature after completion, and an activated carbon adsorbent was added to remove the catalyst to obtain a modified silane; S2. 10-16 parts by weight of modified silane and 18-25 parts by weight of 1,3-propane sultone are dissolved in 1,4-dioxane solvent, and then a sodium hydroxide solution with a mass fraction of 3-5% is added dropwise, and the temperature is raised to 60-80°C for reaction for 6-13 hours. After the reaction, the solvent is removed by concentration under reduced pressure, and the crude product is recrystallized in ethanol to obtain sodium sulfonate modified thiazole.

9. A method for preparing a silica sol-modified emulsion according to any one of claims 1 to 8, characterized in that: The preparation method of the silica sol modified emulsion is as follows: silica sol, emulsifier SR-10, thiazole modified benzoxazine, sodium sulfonate modified thiazole, and water are added into a reactor, and stirred for 10-15 minutes, and then the silica sol modified emulsion is obtained.

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