Flame-retardant liquid and preparation method thereof

Abstract

The invention relates to the technical field of flame retardance, and discloses a flame-retardant liquid and a preparation method thereof.The flame-retardant liquid is obtained by adding zinc borate, a silicon-containing flame retardant and water into a reactor and stirring. The silicon element, the sulfur element, the phosphorus element and the zinc phytate in the silicon-containing flame retardant all have good flame retardant effects. When the silicon element is heated, a vitreous substance can be generated on the surface of the material, and substance transportation and energy transfer are isolated. Phosphorus can generate polyphosphoric acid and metaphosphoric acid which are high in dehydration property during combustion, and the polyphosphoric acid and the metaphosphoric acid are not prone to volatilization and can form a compact protective layer on the surface of the coating, so that the flame-retardant effect is achieved. The sulfur element contained in the polymer can promote the formation of a carbon layer on the surface of the polymer at a high temperature, and the carbon layer can be used as a heat and oxygen barrier layer, so that the combustion speed is reduced, and the flame-retardant effect is achieved. Zinc phytate also has good flame retardance, and meanwhile, an imidazole group in the zinc phytate has a good antibacterial effect.

Description

Technical Field

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

[0002] Flame retardant liquid plays a flame retardant role mainly through dipping, coating, spraying and curing packaging, and has a wide range of applications in the coating field. However, during use, it will be corroded by bacteria, thus affecting its normal use. Therefore, how to avoid this phenomenon is the key to solving the problem.

[0003] For example, patent CN106752885A discloses a flame retardant liquid and a preparation method thereof. The flame retardant liquid obtained by the present invention is a water-based flame retardant liquid, does not contain halogen and aldehyde substances, is used as a flame retardant coating, and has excellent flame retardant and weather resistance, but its antibacterial property is not improved. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies of the prior art, the present invention provides a flame retardant liquid and a preparation method thereof, which have good flame retardant and antibacterial effects.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a flame retardant liquid, comprising the following components by weight: 0.3-0.6 parts by weight of zinc borate, 3-4 parts by weight of a silicon-containing flame retardant, and 8-10 parts by weight of water.

[0008] Preferably, the preparation method of the silicon-containing flame retardant is:

[0009] Step 1: Add 5-8 parts by weight of octamethylcyclotetrasiloxane and 6-10 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.01-0.012 parts by weight of tetramethylammonium hydroxide catalyst, heat the reaction for 2-6 hours, cool and discharge after the reaction, and obtain a double-terminal epoxy silicone oil;

[0010] Step 2: Add Boc-L-cysteine ​​and double-terminal epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, continue to add tetrabutylammonium fluoride catalyst, react at 65-82°C for 5-8h, and then distill under reduced pressure, filter and wash to obtain intermediate 1;

[0011] Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, continue to add p-toluenesulfonic acid catalyst, react at 80-95°C for 6-10h, and after completion, filter and wash to obtain intermediate 2;

[0012] Step 4: Add intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, stir and react at 42-50° C. for 4-6 hours, filter the solvent after the reaction, and wash with distilled water and ethanol in sequence to obtain amino-modified imidazole silane;

[0013] Step 5: adding 9-12 parts by weight of zinc acetate to a deionized water solvent, heating to 76-90° C., adding 11-14 parts by weight of phytic acid thereto, mechanically stirring, and performing a reflux reaction at 85-95° C., washing after completion, and drying to obtain zinc phytate;

[0014] Step six: Add zinc phytate to ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 80-90°C for 1-2h, then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir and react at 82-95°C for 8-10h, filter and wash after completion, and dry to obtain a silicon-containing flame retardant.

[0015] Preferably, the reaction temperature in step 1 is 74-86°C.

[0016] Preferably, in step 2, the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil, and tetrabutylammonium fluoride catalyst is 1:0.4-0.6:0.02-0.03.

[0017] Preferably, in the step three, the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.23-1.46:1:0.021-0.035.

[0018] Preferably, in step 4, the mass ratio of intermediate 2 to trifluoroacetic acid is 1:0.2-0.3.

[0019] Preferably, the reflux reaction in step 5 is performed for 4-7 hours.

[0020] Preferably, in step six, the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazolylsilane, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.2-0.4:1.4-1.7:1:1.2-1.5.

[0021] Preferably, the flame retardant liquid is prepared by adding zinc borate, a silicon-containing flame retardant and water into a reactor and stirring for 3-6 minutes to obtain the flame retardant liquid.

[0022] 3. Beneficial technical effects

[0023] The present invention adds zinc borate, silicon-containing flame retardant and water into a reactor and stirs to obtain a flame retardant liquid. The thiol group in Boc-L-cysteine ​​and the epoxy group in the double-terminal epoxy silicone oil are subjected to a ring-opening reaction to generate a hydroxyl group, and a carboxyl group is introduced at the same time (and the degree of substitution of the sulfur element is increased, further improving its flame retardant effect) to obtain an intermediate 1; the carboxyl group in the intermediate 1 and the hydroxyl group in 4-hydroxyethylimidazole are subjected to an esterification reaction to obtain an intermediate 2, and further deprotected with trifluoroacetic acid to obtain an amino-modified imidazolyl silane; zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazolyl silane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are reacted to obtain a silicon-containing flame retardant.

[0024] Silicon, sulfur, phosphorus and zinc phytate in silicon-containing flame retardants all have good flame retardant effects. When heated, silicon can produce a glassy substance on the surface of the material to isolate material transport and energy transfer. When burned, phosphorus can generate polyphosphoric acid and metaphosphoric acid with strong dehydration properties. Since polyphosphoric acid and metaphosphoric acid are not easy to volatilize, they can form a dense protective layer on the surface of the coating, thus playing a flame retardant role. The sulfur element contained in it can promote the formation of a carbon layer on the surface of the polymer at high temperature. This carbon layer can serve as a barrier layer for heat and oxygen, thereby slowing down the combustion rate and playing a flame retardant role. The zinc phytate in it also has good flame retardancy, and the imidazole group in it has a good antibacterial effect. DETAILED DESCRIPTION

[0025] Example 1

[0026] Step 1: Add 5 parts by weight of octamethylcyclotetrasiloxane and 6 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.01 parts by weight of tetramethylammonium hydroxide catalyst, heat to 74°C and react for 2 hours, then cool and discharge the material after the reaction to obtain a double-terminal epoxy silicone oil;

[0027] Step 2: Add Boc-L-cysteine ​​and double-ended epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, and continue to add tetrabutylammonium fluoride catalyst, wherein the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil and tetrabutylammonium fluoride catalyst is 1:0.4:0.02, react at 65°C for 5h, and then perform reduced pressure distillation after completion, filter and wash to obtain intermediate 1;

[0028] Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.23:1:0.021, react at 80°C for 6h, and after completion, filter and wash to obtain intermediate 2;

[0029] Step 4: adding intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, wherein the mass ratio of intermediate 2 to trifluoroacetic acid is 1:0.2, stirring and reacting at 42° C. for 4 hours, filtering the solvent after the reaction, washing with distilled water and ethanol in turn, to obtain amino-modified imidazole silane;

[0030] Step 5: adding 9 parts by weight of zinc acetate to a deionized water solvent, heating to 76° C., adding 11 parts by weight of phytic acid thereto, mechanically stirring, and performing a reflux reaction at 85° C. for 4 hours. After completion, washing and drying are performed to obtain zinc phytate;

[0031] Step 6: Add zinc phytate to an ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 80°C for 1h, and then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, wherein the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazole silane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.2:1.4:1:1.2, stir and react at 82°C for 8h, filter and wash after completion, and dry to obtain a silicon-containing flame retardant;

[0032] Step 7: Add 0.3 parts by weight of zinc borate, 3 parts by weight of a silicon-containing flame retardant, and 8 parts by weight of water into a reactor and stir for 3 minutes to obtain a flame retardant liquid.

[0033] Example 2

[0034] Step 1: Add 8 parts by weight of octamethylcyclotetrasiloxane and 10 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.012 parts by weight of tetramethylammonium hydroxide catalyst, heat to 86°C and react for 6 hours, then cool and discharge the material after the reaction to obtain a double-terminal epoxy silicone oil;

[0035] Step 2: Add Boc-L-cysteine ​​and double-ended epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, and continue to add tetrabutylammonium fluoride catalyst, wherein the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil and tetrabutylammonium fluoride catalyst is 1:0.6:0.03, react at 82°C for 8h, and then perform reduced pressure distillation after completion, filter and wash to obtain intermediate 1;

[0036] Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.46:1:0.035, react at 95°C for 10 hours, and after completion, filter and wash to obtain intermediate 2;

[0037] Step 4: adding intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, wherein the mass ratio of intermediate 2 to trifluoroacetic acid is 1:0.3, stirring and reacting at 50° C. for 6 hours, filtering the solvent after the reaction, washing with distilled water and ethanol in turn, to obtain amino-modified imidazole silane;

[0038] Step 5: adding 12 parts by weight of zinc acetate to a deionized water solvent, heating to 90° C., and continuously adding 14 parts by weight of phytic acid thereto, mechanically stirring, and performing a reflux reaction at 95° C. for 4-7 hours, washing after completion, and drying to obtain zinc phytate;

[0039] Step 6: Add zinc phytate to an ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 90°C for 2h, and then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, wherein the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazole silane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.4:1.7:1:1.5, stir and react at 95°C for 10h, filter and wash after completion, and dry to obtain a silicon-containing flame retardant;

[0040] Step 7: Add 0.6 parts by weight of zinc borate, 4 parts by weight of silicon-containing flame retardant, and 10 parts by weight of water into a reactor and stir for 6 minutes to obtain a flame retardant liquid.

[0041] Example 3

[0042] Step 1: Add 6 parts by weight of octamethylcyclotetrasiloxane and 8 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.01 parts by weight of tetramethylammonium hydroxide catalyst, heat to 76°C and react for 4 hours, then cool and discharge after the reaction to obtain a double-terminal epoxy silicone oil;

[0043] Step 2: Add Boc-L-cysteine ​​and double-ended epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, and continue to add tetrabutylammonium fluoride catalyst, wherein the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil and tetrabutylammonium fluoride catalyst is 1:0.5:0.02, react at 75°C for 7h, and then perform reduced pressure distillation after completion, filter and wash to obtain intermediate 1;

[0044] Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.24:1:0.021, react at 86°C for 80h, and after completion, filter and wash to obtain intermediate 2;

[0045] Step 4: adding intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, wherein the mass ratio of intermediate 2 to trifluoroacetic acid is 1:0.2, stirring and reacting at 45° C. for 5 hours, filtering the solvent after the reaction, washing with distilled water and ethanol in turn, to obtain amino-modified imidazole silane;

[0046] Step 5: adding 11 parts by weight of zinc acetate to a deionized water solvent, heating to 85° C., and continuing to add 12 parts by weight of phytic acid thereto, mechanically stirring, and reflux reacting at 90° C. for 6 hours, washing after completion, and drying to obtain zinc phytate;

[0047] Step 6: Add zinc phytate to an ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 85°C for 2h, and then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, wherein the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazole silane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.3:1.6:1:1.3, stir and react at 90°C for 9h, filter and wash after the reaction, and dry to obtain a silicon-containing flame retardant;

[0048] Step 7: Add 0.5 parts by weight of zinc borate, 3 parts by weight of silicon-containing flame retardant, and 9 parts by weight of water into a reactor and stir for 5 minutes to obtain a flame retardant liquid.

[0049] Example 4

[0050] Step 1: Add 5 parts by weight of octamethylcyclotetrasiloxane and 6 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.01 parts by weight of tetramethylammonium hydroxide catalyst, heat to 74°C and react for 2 hours, then cool and discharge the material after the reaction to obtain a double-terminal epoxy silicone oil;

[0051] Step 2: Add Boc-L-cysteine ​​and double-ended epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, and continue to add tetrabutylammonium fluoride catalyst, wherein the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil and tetrabutylammonium fluoride catalyst is 1:0.4:0.02, react at 65°C for 5h, and then perform reduced pressure distillation after completion, filter and wash to obtain intermediate 1;

[0052] Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, and continue to add p-toluenesulfonic acid catalyst, wherein the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.46:1:0.035, react at 95°C for 10 hours, and after completion, filter and wash to obtain intermediate 2;

[0053] Step 4: adding intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, wherein the mass ratio of intermediate 2 to trifluoroacetic acid is 1:0.3, stirring and reacting at 50° C. for 6 hours, filtering the solvent after the reaction, washing with distilled water and ethanol in turn, to obtain amino-modified imidazole silane;

[0054] Step 5: adding 11 parts by weight of zinc acetate to a deionized water solvent, heating to 85° C., and continuing to add 12 parts by weight of phytic acid thereto, mechanically stirring, and reflux reacting at 90° C. for 6 hours, washing after completion, and drying to obtain zinc phytate;

[0055] Step 6: Add zinc phytate to an ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 85°C for 2h, and then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, wherein the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazole silane and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.3:1.6:1:1.3, stir and react at 90°C for 9h, filter and wash after the reaction, and dry to obtain a silicon-containing flame retardant;

[0056] Step 7: Add 0.5 parts by weight of zinc borate, 3 parts by weight of silicon-containing flame retardant, and 9 parts by weight of water into a reactor and stir for 5 minutes to obtain a flame retardant liquid.

[0057] Comparative Example 1

[0058] Compared with Example 4, the difference in this comparative example is that amino-modified imidazole silane is used instead of the silicon-containing flame retardant.

[0059] Test: The flame retardant liquid prepared in Examples 1-4 was evenly coated on a pine board of 40 cm×60 cm×2 cm, with a coating thickness of 4 mm. After the flame retardant liquid dried, the fire rating of each template was tested.

[0060] Table 1: Flame retardancy tests.

[0061] project Fire rating Example 1 UL94V-0 Example 2 UL94V-0 Example 3 UL94V-0 Example 4 UL94V-0 Comparative Example 1 UL94V-1

[0062] It can be seen from Table 1 that the flame retardant effects of Examples 1-4 are better than those of Comparative Example 1, which indicates that the flame retardant liquid prepared by the present invention has good flame retardant effect.

[0063] The flame retardant liquid was dissolved and cast into a film to make a thin sheet with a radius of 1 cm; then the bacteria were transferred to a sterile culture medium using an inoculation loop to prepare a bacterial suspension with a concentration of 106 CFU / mL, and then 0.5 mL of the bacterial suspension was transferred dropwise to a culture dish containing beef extract peptone culture medium, and after shaking evenly, the thin sheet was added and cultured in a constant temperature incubator. The diameter of the inhibition zone was measured after 48 h of culture.

[0064] Table 2: Antimicrobial testing.

[0065] project Escherichia coli (mm) Staphylococcus aureus (mm) Example 1 15.6 15.3 Example 2 16.5 16.6 Example 3 16.1 15.1 Example 4 15.4 15.6 Comparative Example 1 10.3 10.2

[0066] It can be seen from Table 2 that the flame retardant liquid Examples 1-4 of the present invention have better antibacterial effects than Comparative Example 1.

[0067] 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 liquid, characterized in that: The invention comprises the following components by weight: 0.3-0.6 parts by weight of zinc borate, 3-4 parts by weight of a silicon-containing flame retardant, and 8-10 parts by weight of water; The preparation method of the silicon-containing flame retardant is: Step 1: Add 5-8 parts by weight of octamethylcyclotetrasiloxane and 6-10 parts by weight of 1,3-diglycidyloxypropyl-1,1,3,3-tetramethyldisiloxane into a reaction kettle, introduce nitrogen protection, then continue to add 0.01-0.012 parts by weight of tetramethylammonium hydroxide catalyst, heat the reaction for 2-6 hours, cool and discharge after the reaction, and obtain a double-terminal epoxy silicone oil; Step 2: Add Boc-L-cysteine ​​and double-terminal epoxy silicone oil to N,N-dimethylformamide solvent, stir to dissolve, continue to add tetrabutylammonium fluoride catalyst, react at 65-82°C for 5-8h, and then distill under reduced pressure, filter and wash to obtain intermediate 1; Step 3: Add 4-hydroxyethylimidazole and intermediate 1 to acetone solvent, stir and mix, continue to add p-toluenesulfonic acid catalyst, react at 80-95°C for 6-10h, and after completion, filter and wash to obtain intermediate 2; Step 4: Add intermediate 2 to a dichloromethane solution containing trifluoroacetic acid, stir and react at 42-50° C. for 4-6 hours, filter the solvent after the reaction, and wash with distilled water and ethanol in sequence to obtain amino-modified imidazole silane; Step 5: adding 9-12 parts by weight of zinc acetate to a deionized water solvent, heating to 76-90° C., adding 11-14 parts by weight of phytic acid thereto, mechanically stirring, and performing a reflux reaction at 85-95° C., washing after completion, and drying to obtain zinc phytate; Step six: Add zinc phytate to ethanol solvent, stir and disperse, then add 3,4-dihydroxybenzaldehyde and amino-modified imidazole silane, reflux at 80-90°C for 1-2h, then continue to add 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stir and react at 82-95°C for 8-10h, filter and wash after completion, and dry to obtain a silicon-containing flame retardant.

2. The flame retardant liquid according to claim 1, characterized in that: The reaction temperature in step 1 is 74-86°C.

3. The flame retardant liquid according to claim 1, characterized in that: In the step 2, the mass ratio of Boc-L-cysteine, double-ended epoxy silicone oil and tetrabutylammonium fluoride catalyst is 1:0.4-0.6:0.02-0.

03.

4. The flame retardant liquid according to claim 1, characterized in that In the step 3, the mass ratio of 4-hydroxyethylimidazole, intermediate 1, and p-toluenesulfonic acid catalyst is 1.23-1.46:1:0.021-0.

035.

5. The flame retardant liquid according to claim 1, characterized in that: In the step 4, the mass ratio of the intermediate 2 to trifluoroacetic acid is 1:0.2-0.

3.

6. The flame retardant liquid according to claim 1, characterized in that: In the step 5, the reflux reaction is performed for 4-7 hours.

7. The flame retardant liquid according to claim 1, characterized in that: In the step six, the mass ratio of zinc phytate, 3,4-dihydroxybenzaldehyde, amino-modified imidazole silane, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 0.2-0.4:1.4-1.7:1:1.2-1.

5.

8. A method for preparing a flame retardant liquid according to any one of claims 1 to 7, characterized in that: The method for preparing the flame retardant liquid is as follows: zinc borate, a silicon-containing flame retardant and water are added into a reactor, and stirred for 3-6 minutes to obtain the flame retardant liquid.