CN116284640A - A kind of preparation method of flame-retardant water-based polyurethane finishing agent for polyester fabric - Google Patents

Abstract

The invention relates to the technical field of flame-retardant water-based polyurethane finishing agents, and discloses a method for preparing a flame-retardant water-based polyurethane finishing agent for polyester fabrics, comprising the following steps: mixing Exolit OP 550, polyethylene glycol 300, isoflurane Mix ketone diisocyanate and catalyst, heat and stir in a water bath, set the temperature at 80-90°C, and react for 1-3h; add dimethylolpropionic acid and pentaerythritol to extend the chain, then add triethanolamine to react, and then dropwise add sulfurous acid The ethanol aqueous solution of sodium hydrogen is capped to obtain flame-retardant water-based polyurethane; the polyester fabric after alkali treatment is irradiated with ultraviolet light under the trigger of a photoinitiator, and then N-methylolacrylamide is added for photografting to obtain modified polyester fabric ; Then carry out flame-retardant finishing to the modified polyester with the flame-retardant water-based polyurethane obtained. The flame retardant finished polyester fabric in the present invention can effectively flame retardant and anti-melt droplet, and its flame retardant performance will not be weakened by water washing.

Description

A kind of preparation method of flame-retardant water-based polyurethane finishing agent for polyester fabric

technical field

The invention belongs to the technical field of flame-retardant water-based polyurethane finishing agents, and more specifically relates to a preparation method of a flame-retardant water-based polyurethane finishing agent for polyester fabrics.

Background technique

Polyester fibers have high strength, high modulus, and low water absorption, and are widely used as civilian fabrics and industrial fabrics. However, polyester is easy to ignite. When burning, it melts and emits black smoke, curls, and melts into beads, causing great safety hazards in the application process.

Polyurethane is an organic polymer containing carbamate chain segment structural units prepared by the reaction of isocyanate and polyester or polyether polyol. Waterborne polyurethane is a polyurethane system in which water replaces organic solvents as the dispersion medium. Water-based polyurethane resin is a uniform emulsion formed by dispersing polyurethane in water. It has the advantages of non-combustibility, low odor, no pollution to the environment, energy saving, and convenient operation and processing. It is widely used as adhesives and coatings. Therefore, polyurethane can be used as an effective flame-retardant polyester fabric finish.

Contents of the invention

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a method for preparing a flame-retardant water-based polyurethane finishing agent for polyester fabrics, which can effectively flame-retardant and anti-droplet , and, while flame retardant, ensure that its flame retardant performance will not be weakened by washing.

To achieve the above object, the invention provides a method for preparing a flame-retardant water-based polyurethane finishing agent for polyester fabrics, comprising the following steps:

Step 1: Mix Exolit OP 550, polyethylene glycol 300, isophorone diisocyanate and catalyst, heat and stir in a water bath, set the temperature at 80-90°C, and react for 1-3 hours;

Step 2: Lower the set temperature to 70-80°C, add dimethylolpropionic acid and pentaerythritol, adjust the viscosity with a solvent, and react for 1-3 hours;

Step 3: Lower the set temperature to 50-60°C, add triethanolamine, and react for 0.5-1h;

Step 4: Put the reactant in step 3 in an ice-water bath at 0-5°C, add a solvent, and then add dropwise an aqueous ethanol solution containing sodium bisulfite, and react for 2-3 hours to obtain a flame-retardant water-based polyurethane;

Step 5: After the polyester fabric is subjected to alkali treatment, take it out for washing and drying;

Step 6: Under ultraviolet light irradiation and photoinitiator triggering, introduce N-methylolacrylamide to carry out photografting on the polyester fabric after alkali treatment to obtain modified polyester;

Step 7: After diluting the flame-retardant water-based polyurethane obtained in step 4 with water, add modified polyester, shake in a water bath at 40-50°C for 20-30min, then pre-bake at 70-75°C for 5-8min, and then heat it at 140°C Bake at -145°C for 3-8 minutes.

In the present invention, Exolit OP 550, polyethylene glycol and isophorone diisocyanate are first subjected to polyester reaction at high temperature, then dimethylol propionic acid and pentaerythritol are added for chain extension, and then sodium bisulfite is used for water-based polyurethane End-blocking to prepare flame-retardant water-based polyurethane. Polyurethane chain extension with dimethylol propionic acid and pentaerythritol has better durability, because the degree of crosslinking after chain extension is greater, and the proportion of grafted end is higher, so its combination with modified polyester is better . However, using sodium bisulfite for end-capping, the end-capped polyurethane can be better combined with the polyester fabric, improving the binding stability, and avoiding the loss of the flame-retardant effect of the polyester after washing. Next, when the flame-retardant water-based polyurethane is used in polyester fabrics, the surface of the polyester fabrics is subjected to ultraviolet light, and N-methylolacrylamide is grafted, which not only makes the polyester fabrics resistant to melting droplets when burning, but also the introduced hydroxyl groups can be It reacts with water-based polyurethane during post-treatment, and it is flame-retardant while ensuring that its flame-retardant performance will not be weakened by washing.

The flame-retardant water-based polyurethane emulsion prepared by the present invention has high solid content and good water solubility. The water-based flame-retardant polyurethane is finished on the modified polyester fabric, which can effectively flame-retardant and anti-melt droplet. Black smoke, green and environmental protection. The flame retardant finished polyester fabric is tested according to the GB 5455-1997 method for vertical combustion of the fabric, the afterburning time is 0 seconds, the smoldering time is 0 seconds, the damaged length is 44mm-46mm, the limiting oxygen index is 27%-29%, and it is washed 50 times After that, the flame retardant effect is still significant.

Further preferably, in step 1, the phosphorus content in the Exolit OP 550 is 16%-18%, the density at 25°C is 1.3g/cm ³ , and the hydroxyl value is 170mg KOH/g.

Further preferably, in step 1, the mass ratio of Exolit OP 550, isophorone diisocyanate and polyethylene glycol 300 is 1:1:0.5; the catalyst is dibutyltin dilaurate.

Further preferably, in step 2, the added amount of dimethylolpropionic acid is 10-11% of the total mass of raw materials in step 1; the added amount of pentaerythritol is 7-8% of the total mass of raw materials in step 1 .

In addition, in step 2, when the temperature of the water bath is adjusted to 70-80°C, the drug cannot be added immediately. The drug can only be added when the system temperature also drops to 70-80°C. During this period, a small amount of solvent is used to adjust the viscosity of the system to prevent the system from solidifying.

Further preferably, in step 3, the ratio of triethanolamine to dimethylolpropionic acid is 1:1.

The purpose of adding triethanolamine in step 3 is to replace the carboxyl group of dimethylol propionic acid, neutralize the dimethylol propionic acid added therein, and increase the hydrophilicity of polyurethane.

Further preferably, in step 4, the ratio of sodium bisulfite to isophorone diisocyanate is 1:1.

Further preferably, in step 5, the alkali treatment of the polyester fabric is as follows: placing the polyester fabric in NaOH with a mass concentration of 40-45g/L and cetyl trimethylmethanol with a mass concentration of 0.5-1g/L In the finishing solution of ammonium bromide, immerse in a water bath at 80-85°C for 50-60min.

Further preferably, in step six, the added amount of the photoinitiator is 2-10% of the polyester fabric mass. It is optimized to account for 2-5% of the total mass of the polyester fabric, and further optimized to account for 3% of the total mass of the polyester fabric.

Further preferably, in step 6, the irradiation time of the ultraviolet light is 3-10 minutes.

Further preferably, in step seven, when the flame-retardant water-based polyurethane is diluted with water, the mass ratio of it to water is 1:2-3.

Compared with the prior art, the present invention has the following advantages: finishing the water-based flame-retardant polyurethane on the modified polyester fabric can effectively flame-retardant and anti-melt droplet, the fabric will be extinguished immediately after leaving the fire, and there will be no black smoke when burning, which is green and environmentally friendly , and, while flame retardant, ensure that its flame retardant performance will not be weakened by washing.

Detailed ways

The technical contents and effects of the present invention will be described in further detail below in conjunction with the examples, but the present invention is not limited thereby.

Example 1

Step 1: Weigh 40g of Exolit OP 550, 20g of polyethylene glycol 300 and 41g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 7.4g of pentaerythritol and 10.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 15mL Dissolve 10.5g of dimethylolpropionic acid, and NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask cools down to 75°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 11.6g of triethanolamine, and when the temperature of the system in the three-necked flask has dropped to 55°C, add triethanolamine to the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 18.7g of sodium bisulfite and dissolve it in 290mL of deionized water, then add 33mL of ethanol and mix evenly, then drop the ethanol aqueous solution containing sodium bisulfite into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water, soak 1000g of polyester cloth after alkali treatment in the obtained solution, , using MUA-165 ultraviolet irradiation device, irradiated with ultraviolet light with a UV irradiance of 3800mW/cm ² , N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes.

Example 2

Step 1: Weigh 50g of Exolit OP 550, 25g of polyethylene glycol 300 and 50g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 9.1g of pentaerythritol and 13.8g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 20mL Dissolve 13.8g of dimethylolpropionic acid, NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 75°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 15.3g of triethanolamine, and when the temperature of the system in the three-necked flask cools down to 55°C, add triethanolamine to the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 22.9g of sodium bisulfite and dissolve it in 300mL of deionized water, then add 33mL of ethanol and mix evenly, then drop the ethanol aqueous solution containing sodium bisulfite into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water, soak 1000g of polyester cloth after alkali treatment in the obtained solution, and initiate the reaction in the photoinitiator TPO Next, the MUA-165 ultraviolet irradiation device is used to irradiate with ultraviolet light with a UV irradiance of 3800mW/cm ² , and N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes.

Example 3

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 11.0g of pentaerythritol and 16.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 25mL Dissolve 16.5g of dimethylolpropionic acid, NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 75°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 18.4g of triethanolamine, and when the system in the three-necked flask cools down to 55°C, add triethanolamine into the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 28.1g of sodium bisulfite and dissolve it in 330mL of deionized water, then add 33mL of ethanol and mix well, then add the ethanol aqueous solution containing sodium bisulfite dropwise into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water, soak 1000g of polyester cloth after alkali treatment in the solution, and initiate Next, the MUA-165 ultraviolet irradiation device is used to irradiate with ultraviolet light with a UV irradiance of 3800mW/cm ² , and N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes.

Comparative example 1 (untreated polyester cloth)

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 11.0g of pentaerythritol and 16.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 25mL Dissolve 16.5g of dimethylolpropionic acid, and NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 70°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 18.4g of triethanolamine, and when the system in the three-necked flask cools down to 55°C, add triethanolamine into the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 28.1g of sodium bisulfite and dissolve it in 330mL of deionized water, then add 33mL of ethanol and mix well, then add the ethanol aqueous solution containing sodium bisulfite dropwise into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a long strip of dry and clean polyester cloth with a width of 30mm and a mass of 30g and soak it in the working Shake in a water bath at 40°C for 30 minutes, then pre-bake at 70°C for 5 minutes in an oven, and then bake at 140°C for 4 minutes.

Comparative example 2 (polyurethane is not end-capped by sodium bisulfite)

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 11.0g of pentaerythritol and 16.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 25mL Dissolve 16.5g of dimethylolpropionic acid, and NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 70°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 18.4g of triethanolamine, and when the system in the three-necked flask cools down to 55°C, add triethanolamine into the three-necked flask and react for 0.5h.

Step 4: Put the three-neck flask in an ice-water bath, cool the system down to 3°C, then add 330mL of deionized water, emulsify for 30min, and obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water, soak 1000g of polyester cloth after alkali treatment in the obtained solution, and initiate the reaction in the photoinitiator TPO Next, the MUA-165 ultraviolet irradiation device is used to irradiate with ultraviolet light with a UV irradiance of 3800mW/cm ² , and N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes. Comparative example 3 (the addition of sodium bisulfite for polyurethane end capping is too little)

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 11.0g of pentaerythritol and 16.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 25mL Dissolve 16.5g of dimethylolpropionic acid, and NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 70°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 18.4g of triethanolamine, and when the system in the three-necked flask cools down to 55°C, add triethanolamine into the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 14.05g of sodium bisulfite and dissolve it in 330mL of deionized water, then add 33mL of ethanol and mix evenly, then drop the ethanol aqueous solution containing sodium bisulfite into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water, soak 1000g of polyester cloth after alkali treatment in the obtained solution, , using MUA-165 ultraviolet irradiation device, irradiated with ultraviolet light with a UV irradiance of 3800mW/cm ² , N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes. Comparative example 4 (polyurethane is to adopt butanediol chain extension)

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without turning off the stirrer, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 27.5g of butanediol, and use 35mL of N-methylpyrrolidone (NMP) to dissolve 16.5g of Dimethylol propionic acid was dissolved, and NMP was used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask was lowered to 70°C, the above-mentioned weighed medicine was added into the three-necked flask, and the reaction was continued for 2 hours.

Step 3: Without turning off the agitator, adjust the temperature of the constant temperature water bath to 55°C, weigh 18.4g of triethanolamine, and when the system in the three-necked flask cools down to 55°C, add triethanolamine into the three-necked flask and react for 0.5h.

Step 4: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 28.1g of sodium bisulfite and dissolve it in 330mL of deionized water, then add 33mL of ethanol and mix well, then add the ethanol aqueous solution containing sodium bisulfite dropwise into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 5: Alkali treatment is carried out to the polyester fabric, take 1000g of dry and clean polyester cloth, and arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L. solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 6: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water. After soaking 1000g of polyester cloth after alkali treatment in the solution, under the triggering of photoinitiator TPO, , using MUA-165 ultraviolet irradiation device, irradiated with ultraviolet light with a UV irradiance of 3800mW/cm ² , N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 7: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 4, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes.

Comparative example 5 (do not add triethanolamine in polyurethane preparation)

Step 1: Weigh 60g of Exolit OP 550, 30g of polyethylene glycol 300 and 60g of isophorone diisocyanate into a three-necked flask with a stirrer, fix the three-necked flask in a constant temperature water bath, and set the temperature to 85°C, then add 0.05 g of dibutyltin dilaurate catalyst with a purity of 95%, start stirring to make the materials fully mixed, and react for 2 hours.

Step 2: Without closing the agitator, adjust the temperature of the constant temperature water bath to 75°C, and wait for the system in the three-necked flask to cool down; weigh 11.0g of pentaerythritol and 16.5g of dimethylolpropionic acid, and use N-methylpyrrolidone ( NMP) 25mL Dissolve 16.5g of dimethylolpropionic acid, and NMP is used to adjust the viscosity of the system; when the temperature of the system in the three-necked flask is lowered to 70°C, add the above-mentioned medicines weighed into the three-necked flask, and continue the reaction for 2h.

Step 3: Put the three-necked flask into an ice-water bath, cool the system down to 3° C., and add 10 mL of ethyl acetate. Weigh 28.1g of sodium bisulfite and dissolve it in 330mL of deionized water, then add 33mL of ethanol and mix well, then add the ethanol aqueous solution containing sodium bisulfite dropwise into the three-necked flask with a constant pressure dropping funnel, and react for 2.5h , to obtain flame-retardant water-based polyurethane.

Step 4: Alkali treatment is carried out on the polyester fabric, take 1000g of dry and clean polyester cloth, arrange the polyester fabric in a finishing place where the mass concentration of NaOH is 40g/L and the mass concentration of cetyltrimethylammonium bromide active agent is 1g/L solution, and heated in a water bath at 80°C, the polyester cloth was soaked in the finishing solution for 50 minutes, then taken out, washed and dried.

Step 5: Weigh 30g of photoinitiator TPO and 30g of N-methylolacrylamide and dissolve them with 1000mL of deionized water. Soak 1000g of polyester cloth after alkali treatment in the solution, and under the triggering of photoinitiator TPO, , using MUA-165 ultraviolet irradiation device, irradiated with ultraviolet light with a UV irradiance of 3800mW/cm ² , N-methylolacrylamide will photograft polyester to obtain modified polyester.

Step 6: Measure 30mL of the flame-retardant water-based polyurethane obtained in step 3, and then add 60mL of deionized water to complete the configuration of the working solution; take a strip-shaped modified polyester with a width of 30mm and a mass of 30g and soak it in the working solution , shaking in a water bath at 40°C for 30 minutes, then pre-baked in an oven at 70°C for 5 minutes, and then baked at 140°C for 4 minutes.

Table 1

In Table 1, the flame retardant effect is the vertical combustion test of the fabric according to the standard GB 5455-1997; the flame retardant effect after 50 times of washing is compared with the flame retardant effect before washing, and the water-bath ratio of each time is 1:20.

As can be seen from Table 1, it can be seen from the comparison of Example 1 and Comparative Example 1 that the polyester cloth is modified and grafted with N-methylol acrylamide, which can effectively resist the droplet, and the hydroxyl on the modified polyester can be compared with the capped The flame-retardant water-based polyurethane reacts more firmly, increases the washing resistance, and still has flame-retardant properties after 50 times of washing. From the comparison of Example 1 and Comparative Example 2, it can be seen that although the uncapped polyurethane has a flame retardant effect, it cannot react with the hydroxyl groups on the modified polyester, so that the flame retardant effect of the modified polyester disappears after washing. From the comparison of Example 1 and Comparative Example 3, it can be seen that the amount of end-blocking agent added is reduced, and the polyurethane is not completely blocked, so the amount of polyurethane reacted with modified polyester will also be reduced, and the flame-retardant effect will be lower after 50 times of washing. Difference. From the comparison of Example 1 and Comparative Example 4, it can be seen that the polyurethane with dimethylol propionic acid and pentaerythritol for chain extension has better durability, because the degree of crosslinking after chain extension is greater, and the proportion of grafted end caps is higher , so its combination with modified polyester is better. However, after using 1,4-butanediol for chain extension, the durability of polyurethane becomes poor, and the flame-retardant effect is poor after 50 times of washing. By contrasting Example 5 with Comparative Example 5, it can be seen that triethanolamine mainly neutralizes the dimethylol propionic acid added therein and increases the hydrophilicity of polyurethane during the preparation of polyurethane. triethanolamine, the resulting polyurethane has poor hydrophilicity. During the finishing process of modified polyester, the water solubility is poor and the bonding effect is poor, so the flame retardant effect is significantly reduced, and the flame retardant effect disappears after washing.

The above-mentioned embodiments of the present invention are only examples for illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other variations and modifications in various forms can be made on the basis of the above description. All the implementation manners cannot be exhaustively listed here. All obvious changes or changes derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims (10)

1. A preparation method for a flame-retardant water-based polyurethane finishing agent for polyester fabrics, characterized in that, comprising the following steps: Step 1: Mix Exolit OP 550, polyethylene glycol 300, isophorone diisocyanate and catalyst, heat and stir in a water bath, set the temperature at 80-90°C, and react for 1-3 hours; Step 2: Lower the set temperature to 70-80°C, add dimethylolpropionic acid and pentaerythritol, adjust the viscosity with a solvent, and react for 1-3 hours; Step 3: Lower the set temperature to 50-60°C, add triethanolamine, and react for 0.5-1h; Step 4: Put the reactant in step 3 in an ice-water bath at 0-5°C, add a solvent, and then add dropwise an aqueous ethanol solution containing sodium bisulfite, and react for 2-3 hours to obtain a flame-retardant water-based polyurethane; Step 5: After the polyester fabric is subjected to alkali treatment, take it out for washing and drying; Step 6: Under ultraviolet light irradiation and photoinitiator triggering, introduce N-methylolacrylamide to carry out photografting on the polyester fabric after alkali treatment to obtain modified polyester; Step 7: After diluting the flame-retardant water-based polyurethane obtained in step 4 with water, add modified polyester, shake in a water bath at 40-50°C for 20-30min, then pre-bake at 70-75°C for 5-8min, and then heat it at 140°C Bake at -145°C for 3-8 minutes. 2. the preparation method of the flame-retardant aqueous polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 1, the content of phosphorus in the described Exolit OP 550 is 16%-18%, 25 ℃ The lower density is 1.3g/cm ³ , and the hydroxyl value is 170mg KOH/g. 3. the preparation method of the flame-retardant aqueous polyurethane finishing agent for polyester fabric as claimed in claim 1 or 2, is characterized in that, in step 1, described Exolit OP 550, isophorone diisocyanate, polyethylene glycol The mass ratio of alcohol 300 is 1:1:0.5; the catalyst is dibutyltin dilaurate. 4. the preparation method of the flame-retardant water-based polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 2, the addition of described dimethylol propionic acid is the total mass of raw materials in step 1 10-11% of 10-11%; the addition of the pentaerythritol is 7-8% of the total mass of raw materials in step one. 5. the preparation method of the flame-retardant aqueous polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 3, the ratio of the amount of substance of described triethanolamine and dimethylol propionic acid is 1:1. 6. the preparation method of the flame-retardant aqueous polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 4, the amount of the substance of described sodium bisulfite and isophorone diisocyanate The ratio is 1:1. 7. the preparation method of the flame-retardant waterborne polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 5, described polyester fabric is carried out alkali treatment as: placing polyester fabric in containing mass concentration In the finishing solution of 40-45g/L NaOH and 0.5-1g/L cetyltrimethylammonium bromide, soak in a water bath at 80-85°C for 50-60min. 8. the preparation method of the flame-retardant aqueous polyurethane finishing agent for polyester fabric as claimed in claim 1, is characterized in that, in step 6, the addition amount of described photoinitiator is the 2-10% of polyester fabric quality. 9. The preparation method of the flame-retardant water-based polyurethane finishing agent for polyester fabric as claimed in claim 1 or 8, characterized in that, in step 6, the irradiation time of the ultraviolet light is 3-10min. 10. the preparation method of the flame-retardant water-based polyurethane finishing agent that is used for polyester fabric as claimed in claim 1, is characterized in that, in step 7, when described flame-retardant water-based polyurethane is diluted with water, its mass ratio with water is 1 : 2-3.