Dyed fabric wet rubbing fastness improver and preparation method thereof

Abstract

The invention relates to the technical field of textile printing and dyeing, in particular to a dyed fabric wet rubbing fastness improver and a preparation method thereof. The preparation method comprises the following steps: firstly, preparing a polyurethane prepolymer from polytetrahydrofuran ether glycol and diisocyanate, then preparing a polyurethane intermediate from micromolecular diol 1, 4-butanediol and a tertiary amine type diol chain extender N-butyl diethanol amine as chain extenders, then preparing polyurethane from diethyl iminodiacetate as an end-capping reagent, and finally preparing the polyurethane prepolymer. And finally, bromobutane is used as a quaternization reagent to prepare cationic polyurethane, the cationic polyurethane and acrylamide are polymerized and crosslinked under the action of an initiator to prepare the dyed fabric wet rubbing fastness improver, and an organic silicon chain segment is introduced into a polyurethane prepolymer molecular chain, so that the dyed fabric wet rubbing fastness improver is prepared. The prepared wet rubbing fastness improver for the dyed fabric can effectively improve the wet rubbing fastness of the dyed fabric, and meanwhile, the dyed fabric treated by the wet rubbing fastness improver for the dyed fabric has good softness.

Description

Technical Field

[0001] The present invention relates to the technical field of textile printing and dyeing, and particularly relates to a wet rubbing fastness improver for dyed fabrics and a preparation method thereof. Background Art

[0002] Reactive dyes have various characteristics such as bright color, low price, and convenient use, and are widely used in the field of fabric dyeing. However, reactive dye molecules have high water solubility, and the wet rubbing fastness of fabrics dyed with reactive dyes is poor, and it is necessary to improve the wet rubbing fastness of dyed fabrics.

[0003] Chinese Patent CN101492883B discloses a polymer wet rubbing fastness improver, which is a copolymer formed by 2-acrylamide-2-methylpropanesulfonic acid, acrylamide, dimethyldiallylammonium chloride, dimethyldiallylammonium, high molecular weight PVP, and an emulsifier through an initiator. The cationic groups, the molecular attraction between the fiber, the reactive groups, and the film-forming property of the colloid protective agent PE are used to improve the dyeing fastness and rubbing fastness of fabrics during the textile dyeing process. However, the cationic groups are only provided by dimethyldiallylammonium chloride, the content of cationic groups is low, and the reaction raw material 2-acrylamide-2-methylpropanesulfonic acid contains anionic groups, which can weaken the cationicity of the wet rubbing fastness improver and have a weak binding ability with water-soluble dyes containing anionic groups. In addition, the film formed by the acrylic polymer will make the hand feeling of the fabric hard and reduce the wearing comfort of the fabric. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a wet rubbing fastness improver for dyed fabrics to solve the problems that the binding ability between the wet rubbing fastness improver and the fabric in the prior art needs to be improved and the hand feeling of the fabric is reduced.

[0005] In order to achieve the above object, the technical scheme adopted by the present invention is as follows:

[0006] A preparation method of a wet rubbing fastness improver for dyed fabrics includes the following steps:

[0007] Step 1: Mix polytetrahydrofuran ether glycol with hydroxyl-terminated vinyl fluorosilicone oil, add diisocyanate and dibutyltin dilaurate, react, and after the reaction is completed, cool down and filter to obtain an organosilicon-modified polyurethane prepolymer;

[0008] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer, react, and after the reaction is completed, obtain a polyurethane intermediate;

[0009] Step 3: Add the polyurethane intermediate to acetonitrile. After stirring and dispersing, add diethyl iminodiacetate and triethylamine, and react. After the reaction is completed, perform rotary evaporation, washing, filtration, and drying to obtain polyurethane.

[0010] Step 4: Add the polyurethane and bromobutane to chloroform and react. After the reaction is completed, perform rotary evaporation, add deionized water, and purify and separate to obtain a cationic polyurethane solution.

[0011] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, raise the temperature to the set temperature, dropwise add the initiator solution, and react. After the reaction is completed, cool down to obtain a wet rubbing fastness improver for dyed fabrics.

[0012] Preferably, in Step 1: The mass ratio of the diisocyanate, polytetrahydrofuran ether glycol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is (38 - 42):(10 - 15):(12 - 16):(0.1 - 0.3), and the reaction conditions are to react at a temperature of 85 - 95 °C for 2 - 3 h.

[0013] Preferably, the diisocyanate includes hexamethylene diisocyanate.

[0014] Preferably, the hydroxyl-terminated vinyl fluorosilicone oil in Step 1 is prepared by the following steps:

[0015] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, add deionized water, a base catalyst, and cyclodextrin, and react. After the reaction is completed, neutralize and purify to obtain hydroxyl-terminated vinyl fluorosilicone oil.

[0016] Preferably, the mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, the base catalyst, and cyclodextrin is 46.9:(8 - 12):(10 - 15):(3 - 6):(0.03 - 0.05):(0.005 - 0.01), and the reaction conditions are to react at a temperature of 40 - 60 °C for 1 - 3 h.

[0017] Preferably, the base catalyst includes potassium hydroxide.

[0018] Preferably, in Step 2: The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is (130 - 150):(1 - 2):(0.5 - 1), and the reaction conditions are to react at a temperature of 45 - 55 °C for 1 - 3 h.

[0019] Preferably, in the step 3, the mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is (65 - 82):(1200 - 1600):(3 - 5):(0.5 - 1), and the reaction conditions are to react at a temperature of 50 - 70 °C for 1 - 2 h.

[0020] Preferably, in the step 4, the mass ratio of the polyurethane, bromobutane, and chloroform is 100:(15 - 20):(800 - 1200), the reaction conditions are to reflux and react at a temperature of 60 - 80 °C for 2 - 4 h, and the addition amount of deionized water is 1 - 2 times the mass of chloroform.

[0021] Preferably, in the step 5, the mass ratio of the cationic polyurethane solution, acrylamide, and initiator solution is 100:(2 - 4):(3 - 5), the dropping time of the initiator solution is 30 - 60 min, and the reaction conditions are to react at a set temperature for 1 - 3 h;

[0022] The set temperature is 60 - 80 °C.

[0023] Preferably, the initiator solution includes an aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride, and the aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride includes a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride.

[0024] The present invention also discloses a wet rubbing fastness improver for dyed fabrics prepared by using the preparation method of the wet rubbing fastness improver for dyed fabrics as described above.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The wet rubbing fastness improver in the present invention is a cationic aqueous polyurethane wet rubbing fastness improver. First, a polyurethane prepolymer is prepared from polytetrahydrofuran glycol and diisocyanate, and then a polyurethane intermediate is prepared by using small molecule glycol 1,4-butanediol and tertiary amine type glycol chain extender N-butyl diethanolamine as chain extenders. The polyurethane intermediate reacts with a capping agent to obtain a polyurethane. Further, the polyurethane reacts with a quaternization reagent, and the tertiary amine group in the chain extender molecule is converted into a quaternary ammonium salt to obtain a cationic polyurethane. The cationic groups combine with water-soluble dyes containing anionic groups (such as carboxyl groups, sulfonic acid groups, etc.) to form salts, and the floating color is fixed on the fiber surface;

[0027] In the present invention, due to the presence of flexible molecular chains of polyether polyols in the polyurethane molecules, the polyurethane has good toughness and flexibility, and has little influence on the hand feeling of the fabric after film formation. In addition, when preparing the polyurethane prepolymer, hydroxyl-terminated vinyl fluorosilicone oil is introduced. The introduction of the silicone molecular chain can endow the fabric with good softness and smoothness, improve the hand feeling of the fabric, reduce the friction coefficient on the fabric surface, and make the dye not easily fall off due to friction; the introduction of silicone can reduce the surface energy of the fabric, improve the hydrophobic effect, and thus improve the wet rubbing fastness of the dyed fabric; the introduction of vinyl enables the cationic polyurethane to crosslink and copolymerize with the crosslinking agent acrylamide under the action of an initiator. The formed macromolecular network structure has the characteristics of forming a film horizontally and being cationic longitudinally. The film formation can isolate the dye from the outside and hinder the transfer and staining of water solubility; the introduction of organic fluorides can also improve the hydrophobic performance of the fabric and further improve the wet rubbing fastness of the dyed fabric;

[0028] In the present invention, diethyl iminodiacetate is used as the capping agent for the polyurethane intermediate. The imino group reacts with the isocyanate group. While protecting the active group isocyanate group, the imino group is converted into a tertiary amine group. When the polyurethane reacts with the quaternization reagent, more quaternary ammonium salt structures can be formed, and the binding ability with water-soluble dyes is stronger. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is the process flow chart for the preparation of the wet rubbing fastness improver for dyed fabrics in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] Example 1

[0031] This example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, including the following steps:

[0032] Step 1: Mix polytetrahydrofuran ether diol with hydroxyl-terminated vinyl fluorosilicone oil, add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran ether diol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is 38:10:12:0.1. React at 85 °C for 3 h. After the reaction is completed, cool down to below 10 °C and filter to obtain an organosilicon-modified polyurethane prepolymer;

[0033] Among them, the hydroxyl-terminated vinyl fluorosilicone oil is prepared through the following steps:

[0034] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, and add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:8:10:3:0.03:0.005. React at 40 °C for 3 h. After the reaction, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180 °C and evacuate to obtain hydroxyl-terminated vinyl fluorosilicone oil;

[0035] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is 130:1:0.5. React at 45 °C for 3 h. After the reaction, obtain a polyurethane intermediate;

[0036] Step 3: Add the polyurethane intermediate to acetonitrile. After stirring and dispersing, add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 65:1200:3:0.5. React at 50 °C for 2 h. After the reaction, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and dry in a vacuum drying oven at 50 °C for 24 h to obtain polyurethane;

[0037] Step 4: Add the polyurethane to chloroform. After stirring and dissolving, add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:15:800. React under reflux at 60 °C for 4 h. After the reaction, rotary evaporate to remove chloroform at 40 °C. Add deionized water twice the mass of bromobutane to the residue and stir at a stirring speed of 200 r / min for 30 min. Let it stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution;

[0038] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, heat up to 60 °C and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 30 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:2:3. React at 60 °C for 3 h. After the reaction, cool down to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0039] Example 2

[0040] This example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, including the following steps:

[0041] Step 1: Mix polytetrahydrofuran ether glycol with hydroxyl-terminated vinyl fluorosilicone oil, add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran ether glycol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is 42:15:16:0.3. React at 95°C for 2 h. After the reaction is completed, cool down to below 10°C and filter to obtain an organosilicon-modified polyurethane prepolymer;

[0042] Among them, the hydroxyl-terminated vinyl fluorosilicone oil is prepared through the following steps:

[0043] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:12:15:6:0.05:0.01. React at 60°C for 1 h. After the reaction is completed, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180°C and evacuate to obtain hydroxyl-terminated vinyl fluorosilicone oil;

[0044] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is 150:2:1. React at 55°C for 1 h. After the reaction is completed, obtain a polyurethane intermediate;

[0045] Step 3: Add the polyurethane intermediate to acetonitrile, stir and disperse it, then add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 82:1600:5:1. React at 70°C for 1 h. After the reaction is completed, rotary evaporate to remove acetonitrile at 40°C. Wash the residue with cyclohexane, filter, and place it in a vacuum drying oven at 50°C for drying for 24 h to obtain polyurethane;

[0046] Step 4: Add the polyurethane to chloroform, stir to dissolve it, then add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:20:1200. React under reflux at 80°C for 2 h. After the reaction is completed, rotary evaporate to remove chloroform at 40°C. Add deionized water with a mass 1 time that of bromobutane to the residue, stir at a stirring speed of 200 r / min for 30 min, let it stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution;

[0047] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, heat up to 80 °C, and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 60 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:4:5. React at 80 °C for 1 h. After the reaction is completed, cool down to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0048] Example 3

[0049] This example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, which includes the following steps:

[0050] Step 1: Mix polytetrahydrofuran ether glycol with hydroxyl-terminated vinyl fluorosilicone oil, add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran ether glycol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is 39:11:13:0.15. React at 90 °C for 2.5 h. After the reaction is completed, cool down to below 10 °C and filter to obtain an organosilicon-modified polyurethane prepolymer.

[0051] Among them, the hydroxyl-terminated vinyl fluorosilicone oil is prepared through the following steps:

[0052] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:9:11:4:0.04:0.006. React at 50 °C for 2 h. After the reaction is completed, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180 °C and evacuate to obtain the hydroxyl-terminated vinyl fluorosilicone oil.

[0053] Step 2: Add N-butyl diethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyl diethanolamine, and 1,4-butanediol is 135:1.2:0.6. React at 50 °C for 2 h. After the reaction is completed, obtain a polyurethane intermediate.

[0054] Step 3: Add the polyurethane intermediate into acetonitrile. After stirring and dispersing, add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 69:1300:3.5:0.6. React at 60 °C for 1.5 h. After the reaction is completed, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and dry in a vacuum drying oven at 50 °C for 24 h to obtain polyurethane;

[0055] Step 4: Add the polyurethane into chloroform. After stirring and dissolving, add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:16:900. React under reflux at 70 °C for 3 h. After the reaction is completed, rotary evaporate to remove chloroform at 40 °C. Add deionized water 1.5 times the mass of bromobutane to the residue, stir at a stirring speed of 200 r / min for 30 min, let stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution;

[0056] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, raise the temperature to 70 °C, and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 45 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:2.5:3.5. React at 70 °C for 2 h. After the reaction is completed, cool to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0057] Example 4

[0058] This example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, including the following steps:

[0059] Step 1: Mix polytetrahydrofuran glycol with hydroxyl-terminated vinyl fluorosilicone oil, and add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran glycol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is 40:12.5:14:0.2. React at 90 °C for 2.5 h. After the reaction is completed, cool to below 10 °C and filter to obtain an organosilicon-modified polyurethane prepolymer;

[0060] Among them, the hydroxyl-terminated vinyl fluorosilicone oil is prepared through the following steps:

[0061] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, and add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:10:12.5:4.5:0.04:0.007. React at 50 °C for 2 h. After the reaction, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180 °C and evacuate to obtain hydroxyl-terminated vinyl fluorosilicone oil;

[0062] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is 140:1.5:0.75. React at 50 °C for 2 h. After the reaction, obtain a polyurethane intermediate;

[0063] Step 3: Add the polyurethane intermediate to acetonitrile. After stirring and dispersing, add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 73:1400:4:0.75. React at 60 °C for 1.5 h. After the reaction, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and dry in a vacuum drying oven at 50 °C for 24 h to obtain polyurethane;

[0064] Step 4: Add the polyurethane to chloroform. After stirring and dissolving, add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:17.5:1000. Reflux and react at 70 °C for 3 h. After the reaction, rotary evaporate to remove chloroform at 40 °C. Add deionized water 1.5 times the mass of bromobutane to the residue and stir at a stirring speed of 200 r / min for 30 min. After standing for 2 h, remove the lower organic layer to obtain a cationic polyurethane solution;

[0065] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, heat up to 70 °C and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 45 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:3:4. React at 70 °C for 2 h. After the reaction, cool down to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0066] Example 5

[0067] This embodiment discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, comprising the following steps:

[0068] Step 1: Mix polytetrahydrofuran ether glycol with hydroxyl-terminated vinyl fluorosilicone oil, add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran ether glycol, hydroxyl-terminated vinyl fluorosilicone oil, and dibutyltin dilaurate is 40:12.5:14:0.2. React at 90 °C for 2.5 h. After the reaction ends, cool down to below 10 °C and filter to obtain an organosilicon-modified polyurethane prepolymer.

[0069] Among them, the hydroxyl-terminated vinyl fluorosilicone oil is prepared through the following steps:

[0070] Mix trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, and hexamethylcyclotrisiloxane, add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:10:12.5:4.5:0.04:0.007. React at 50 °C for 2 h. After the reaction ends, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180 °C and evacuate to obtain hydroxyl-terminated vinyl fluorosilicone oil.

[0071] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is 140:1.5:0.75. React at 50 °C for 2 h. After the reaction ends, obtain a polyurethane intermediate.

[0072] Step 3: Add the polyurethane intermediate to acetonitrile, stir and disperse it, then add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 73:1400:4:0.75. React at 60 °C for 1.5 h. After the reaction ends, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and dry it in a vacuum drying oven at 50 °C for 24 h to obtain polyurethane.

[0073] Step 4: Add the polyurethane to chloroform, stir to dissolve it, then add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:17.5:1000. React under reflux at 70 °C for 3 h. After the reaction ends, rotary evaporate to remove chloroform at 40 °C. Add deionized water 1.5 times the mass of bromobutane to the residue, stir at a stirring speed of 200 r / min for 30 min, let it stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution.

[0074] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, heat up to 70°C, and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 45 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:3:4. React at 70°C for 2 h. After the reaction is completed, cool down to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0075] Comparative Example 1

[0076] This comparative example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, including the following steps:

[0077] Step 1: Mix polytetrahydrofuran glycol with hydroxyl-terminated fluorosilicone oil, add hexamethylene diisocyanate and dibutyltin dilaurate. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran glycol, hydroxyl-terminated fluorosilicone oil, and dibutyltin dilaurate is 38:10:12:0.1. React at 85°C for 3 h. After the reaction is completed, cool down to below 10°C and filter to obtain an organosilicon-modified polyurethane prepolymer;

[0078] Among them, the hydroxyl-terminated fluorosilicone oil is prepared through the following steps:

[0079] Mix 3,3,3-trifluoropropylmethylcyclotrisiloxane and hexamethylcyclotrisiloxane, add deionized water, potassium hydroxide, and cyclodextrin. The mass ratio of 3,3,3-trifluoropropylmethylcyclotrisiloxane, hexamethylcyclotrisiloxane, deionized water, potassium hydroxide, and cyclodextrin is 46.9:10:3:0.03:0.005. React at 40°C for 3 h. After the reaction is completed, add 2 mol / L hydrochloric acid to the reaction mixture for neutralization. The pH value of the neutralized reaction mixture is 7. Heat up to 180°C and evacuate to obtain hydroxyl-terminated vinyl fluorosilicone oil;

[0080] Step 2: Add N-butyldiethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer. The mass ratio of the organosilicon-modified polyurethane prepolymer, N-butyldiethanolamine, and 1,4-butanediol is 130:1:0.5. React at 45°C for 3 h. After the reaction is completed, obtain a polyurethane intermediate;

[0081] Step 3: Add the polyurethane intermediate into acetonitrile. After stirring and dispersing, add acrylamide and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, acrylamide, and triethylamine is 65:1200:1.1:0.5. React at 50 °C for 2 h. After the reaction is completed, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and dry in a vacuum drying oven at 50 °C for 24 h to obtain polyurethane;

[0082] Step 4: Add the polyurethane into chloroform. After stirring and dissolving, add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:15:800. React under reflux at 60 °C for 4 h. After the reaction is completed, rotary evaporate to remove chloroform at 40 °C. Add deionized water twice the mass of bromobutane to the residue, stir at a stirring speed of 200 r / min for 30 min, let stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution;

[0083] Step 5: Heat the cationic polyurethane solution to 60 °C, and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 30 min. The mass ratio of the cationic polyurethane solution to the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 102:3. React at 60 °C for 3 h. After the reaction is completed, cool to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0084] Comparative Example 2

[0085] This comparative example discloses a preparation method of a wet rubbing fastness improver for dyed fabrics, including the following steps:

[0086] Step 1: Add hexamethylene diisocyanate and dibutyltin dilaurate to polytetrahydrofuran glycol. The mass ratio of hexamethylene diisocyanate, polytetrahydrofuran glycol, and dibutyltin dilaurate is 38:22:0.1. React at 85 °C for 3 h. After the reaction is completed, cool to below 10 °C and filter to obtain a polyurethane prepolymer;

[0087] Step 2: Add N-butyl diethanolamine and 1,4-butanediol to the polyurethane prepolymer. The mass ratio of the polyurethane prepolymer, N-butyl diethanolamine, and 1,4-butanediol is 130:1:0.5. React at 45 °C for 3 h. After the reaction is completed, obtain a polyurethane intermediate;

[0088] Step 3: Add the polyurethane intermediate into acetonitrile. After stirring and dispersing, add diethyl iminodiacetate and triethylamine. The mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate, and triethylamine is 65:1200:3:0.5. React at 50 °C for 2 h. After the reaction is completed, rotary evaporate to remove acetonitrile at 40 °C. Wash the residue with cyclohexane, filter, and place it in a vacuum drying oven at 50 °C for drying for 24 h to obtain polyurethane;

[0089] Step 4: Add the polyurethane into chloroform. After stirring and dissolving, add bromobutane. The mass ratio of the polyurethane, bromobutane, and chloroform is 100:15:800. React under reflux at 60 °C for 4 h. After the reaction is completed, rotary evaporate to remove chloroform at 40 °C. Add deionized water with a mass twice that of bromobutane to the residue, stir at a stirring speed of 200 r / min for 30 min, let it stand for 2 h, and then remove the lower organic layer to obtain a cationic polyurethane solution;

[0090] Step 5: Add acrylamide to the cationic polyurethane solution. After stirring and mixing, raise the temperature to 60 °C, and dropwise add a 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride. The dropping time of the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 30 min. The mass ratio of the cationic polyurethane solution, acrylamide, and the 0.5 wt% aqueous solution of 2,2'-azobis(2-methylpropionamidine) dihydrochloride is 100:2:3. React at 60 °C for 3 h. After the reaction is completed, cool down to room temperature to obtain a wet rubbing fastness improver for dyed fabrics.

[0091] In the above examples and comparative examples: polytetrahydrofuran ether diol was purchased from Xuzhou Yihuiyang New Materials Co., Ltd., product number: PTMG650, molecular weight: 650±25; hexamethylene diisocyanate was purchased from Wuhan Kemic Biopharmaceutical Technology Co., Ltd., CAS number: 822-06-0; trifluoropropyl methyl cyclotrisiloxane was purchased from Xinyuan Chemistry (Shandong) Co., Ltd., CAS number: 2374-14-3; tetramethyltetravinyl cyclotetrasiloxane was purchased from Zhongshan Dixin Chemical Co., Ltd., CAS number: 2554-06-5; hexamethyl cyclotrisiloxane was purchased from Zhejiang Hengye Cheng Organosilicon Co., Ltd., CAS number: 541-05-9; cyclodextrin was β-cyclodextrin, purchased from Sinopharm Chemical Reagent Co., Ltd., CAS number: 7585-39-9; N-butyl diethanolamine was purchased from Sinopharm Chemical Reagent Co., Ltd., N-butyl diethanolamine; 1,4-butanediol was purchased from Shanghai Kanglang Biotechnology Co., Ltd., CAS number: 110-63-4; diethyl iminodiacetate was purchased from Zhongxin Chenshi (Wuhan) Technology Co., Ltd., CAS number: 6290-05-7; bromobutane was purchased from Sinopharm Chemical Reagent Co., Ltd., CAS number: 109-65-9; acrylamide was purchased from Shanghai Qian Chemical Co., Ltd., CAS number: 79-06-1; azodiisobutyramidine hydrochloride was purchased from Sinopharm Chemical Reagent Co., Ltd., CAS number: 2997-92-4.

[0092] Test Example

[0093] Performance tests were carried out on the wet rubbing fastness improvers of the dyed fabrics prepared in Examples 1-5 and Comparative Examples 1-2:

[0094] (1) Wet rubbing fastness test: The unfixed Remazol ESP navy reactive dye-dyed denim fabric was padded twice (padding rate 85%) with the wet rubbing fastness improvers of the dyed fabrics prepared in Examples 1-5 and Comparative Examples 1-2, dried at 100 °C, and baked at 140 °C for 5 min. Then, referring to the standard GB / T 3920-2008 "Textiles - Tests for colour fastness - Colour fastness to rubbing", the wet rubbing fastness of 7 groups of denim fabric samples treated with the wet rubbing fastness improvers of the dyed fabrics prepared in Examples 1-5 and Comparative Examples 1-2 and the untreated denim fabric samples was determined. The results are shown in Table 1:

[0095] Table 1

[0096]

[0097] As can be seen from Table 1, the wet rubbing fastness improver for dyed fabrics prepared by the present invention can effectively improve the wet rubbing fastness of dyed fabrics. The wet rubbing fastness improver is a cationic aqueous polyurethane wet rubbing fastness improver. The tertiary amine groups in the tertiary amine type diol chain extender and the tertiary amine groups formed by the conversion of the end-capping agent containing imino group react with the quaternization reagent to generate a large number of quaternary ammonium salt structures, which have a strong binding ability with water-soluble dyes containing anionic groups; when preparing the polyurethane prepolymer, hydroxy-terminated vinyl fluorosilicone oil is introduced. The introduction of the silicone molecular chain and organofluoride can improve the hydrophobic property of the fabric and the wet rubbing fastness of the dyed fabric; the introduction of vinyl enables the cationic polyurethane to crosslink and copolymerize with the crosslinking agent acrylamide under the action of an initiator, isolating the dye from the outside through film formation and hindering the transfer and staining of water solubility. Compared with Example 1, in Comparative Example 1, hydroxy-terminated fluorosilicone oil is used to replace hydroxy-terminated vinyl fluorosilicone oil, and acrylamide is used to replace diethyl iminodiacetate as the end-capping agent. The crosslinking polymerization between polyurethane molecules is only achieved through acrylamide located at the end of the polyurethane, resulting in a decrease in the degree of crosslinking polymerization, a weakening of the film-forming performance, a reduction in the formed quaternary ammonium salt structure, and a significant decrease in the wet rubbing fastness; in Comparative Example 2, when preparing the polyurethane prepolymer, hydroxy-terminated vinyl fluorosilicone oil is not added, the polyurethane cannot participate in the crosslinking polymerization of alkenyl, the film-forming performance is significantly weakened, and the hydrophobic effect of the silicone molecular chain and organofluoride is lacking, resulting in a large reduction in the wet rubbing fastness.

[0098] (2) Softness test: The undyed denim fabric dyed with Remazol ESP navy reactive dye is passed through the wet rubbing fastness improver for dyed fabrics prepared in Examples 1-5 and Comparative Examples 1-2 by two-dip two-roll (the liquor ratio is 85%), dried at 100 °C, and baked at 140 °C for 5 min. Then, a group of 5 professionals is used to touch and score the 7 groups of denim fabric samples treated with the wet rubbing fastness improver for dyed fabrics prepared in Examples 1-5 and Comparative Examples 1-2 and the untreated denim fabric samples, and comprehensively rank them according to the softness and smoothness of the fabric. The hand feeling is divided into five grades, with 5 being the best hand feeling and 1 being the worst hand feeling. The test results are shown in Table 2:

[0099] Table 2

[0100]

[0101] As can be seen from Table 2, the dyed fabric treated with the wet rubbing fastness improver for dyed fabrics prepared by the present invention has good softness. The toughness and flexibility of the polyurethane are good, and it has little impact on the hand feeling of the fabric. At the same time, when preparing the polyurethane prepolymer, hydroxy-terminated vinyl fluorosilicone oil is introduced. The introduction of the silicone molecular chain can endow the fabric with good softness and smoothness and improve the hand feeling of the fabric. Compared with Example 1, in Comparative Example 2, when preparing the polyurethane prepolymer, hydroxy-terminated vinyl fluorosilicone oil is not added, and it has no improvement effect on the hand feeling of the fabric.

[0102] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a dyed fabric wet rubbing fastness improving agent, characterized in that: The following steps are involved: Step 1: Mix polytetrahydrofuran ether diol and hydroxyl-terminated vinyl fluorosilicone oil, add diisocyanate and dibutyltin dilaurate, react, cool after the reaction, filter, and obtain a silicone-modified polyurethane prepolymer; Step 2: Add N-butyl diethanolamine and 1,4-butanediol to the organosilicon-modified polyurethane prepolymer to react, and after the reaction is completed, a polyurethane intermediate is obtained; Step 3, adding acetonitrile to the polyurethane intermediate, stirring and dispersing, adding diethyl iminodiacetate and triethylamine, reacting, and after the reaction is completed, rotary evaporation, washing, filtering, and drying to obtain polyurethane; Step 4: adding polyurethane to chloroform, stirring to dissolve, adding butyl bromide, reacting, and after the reaction is completed, rotary evaporation, and then adding deionized water for purification and separation to obtain a cationic polyurethane solution; Step 5: Add acrylamide to the cationic polyurethane solution, stir and mix, heat to a set temperature, drop an initiator solution, react, and after the reaction is completed, cool to obtain a dyed fabric wet friction fastness enhancer.

2. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: In the step 1, the mass ratio of diisocyanate, polytetramethylene ether glycol, hydroxyl-terminated vinyl fluorosilicone oil and dibutyltin dilaurate is (38-42):(10-15):(12-16):(0.1-0.3), and the reaction conditions are 85-95° C. for 2-3 hours; The diisocyanate includes hexamethylene diisocyanate.

3. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: The hydroxyl-terminated vinyl fluorosilicone oil in step 1 is prepared by the following steps: The trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane and hexamethylcyclotrisiloxane are mixed, deionized water, an alkali catalyst and cyclodextrin are added, and the mixture is reacted. After the reaction is completed, the mixture is neutralized and purified to obtain hydroxyl-terminated vinyl fluorosilicone oil.

4. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 3, characterized in that: The mass ratio of trifluoropropylmethylcyclotrisiloxane, tetramethyltetravinylcyclotetrasiloxane, hexamethylcyclotrisiloxane, deionized water, base catalyst and cyclodextrin is 46.9:(8-12):(10-15):(3-6):(0.03-0.05):(0.005-0.01), and the reaction conditions are 40-60° C. for 1-3 hours; The base catalyst includes potassium hydroxide.

5. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: In the step 2, the mass ratio of the silicone-modified polyurethane prepolymer, N-butyl diethanolamine, and 1,4-butanediol is (130-150):(1-2):(0.5-1), and the reaction conditions are to react at a temperature of 45-55° C. for 1-3 hours.

6. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: In the step 3, the mass ratio of the polyurethane intermediate, deionized water, diethyl iminodiacetate and triethylamine is (65-82):(1200-1600):(3-5):(0.5-1), and the reaction conditions are 50-70° C. for 1-2 hours.

7. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: In the step 4, the mass ratio of polyurethane, butyl bromide and chloroform is 100:(15-20):(800-1200), the reaction conditions are reflux reaction at 60-80° C. for 2-4 hours, and the amount of deionized water added is 1-2 times the mass of chloroform.

8. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 1, characterized in that: In the step 5, the mass ratio of the cationic polyurethane solution, acrylamide and initiator solution is 100:(2-4):(3-5), the initiator solution is added for 30-60 min, and the reaction is carried out at a set temperature for 1-3 h. The set temperature is 60-80°C.

9. The method for preparing a dyed fabric wet rubbing fastness improving agent according to claim 8, characterized in that: The initiator solution includes an aqueous solution of azobisisobutylamidine hydrochloride, and the aqueous solution of azobisisobutylamidine hydrochloride includes a 0.5 wt % aqueous solution of azobisisobutylamidine hydrochloride.

10. A dyed fabric wet rubbing fastness improving agent prepared by the method for preparing a dyed fabric wet rubbing fastness improving agent according to any one of claims 1 to 9.

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