High-concentration formaldehyde-free color fixing agent and preparation method thereof

Abstract

The invention relates to the technical field of color fixing agents, in particular to a high-concentration formaldehyde-free color fixing agent and a preparation method thereof.The high-concentration formaldehyde-free color fixing agent is prepared from, by weight, 60-75 parts of dimethyl diallyl ammonium chloride solution, 1-7 parts of dicyandiamide derivative, 5-12 parts of N-vinyl pyrrolidone, 0.1-0.5 part of initiator and 10-25 parts of deionized water. Through reasonable raw material selection and reaction condition control, the prepared color fixing agent shows better comprehensive performance in the aspects of acid and sweat stain resistance color fastness and foam performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fixing agent, in particular to a high-concentration formaldehyde-free fixing agent and a preparation method thereof. BACKGROUND

[0002] In the process of textile processing, color fastness after dyeing is a key indicator to measure product quality. However, the binding force between many dyes and fibers is not strong enough, and the phenomenon of color fading and staining easily occurs during subsequent washing, rubbing, sweat action or daily use. In order to solve the problem of color fading, fixing agent is widely used as a finishing aid in traditional process. Early fixing agents are mostly formaldehyde-containing compounds, which can effectively improve color fastness by combining with dye anion groups or forming cross-linked network. However, they contain and release free formaldehyde after use, which has strong irritation to human skin, respiratory tract and nervous system, and long-term contact is harmful to health. Formaldehyde-free fixing agents mainly use formaldehyde-free synthetic monomers, such as polyethylene polyamine and its modified products, polydimethyl diallyl ammonium chloride (polyquaternary ammonium salt), polyamine, etc., which can fix color through cross-linking or cationic charge adsorption.

[0003] In the prior art, high-concentration formaldehyde-free fixing agent (especially containing polyquaternary ammonium salt) is prone to produce more and stable foam when used in high-speed stirring or overflow. Foam not only affects the stability of working liquid and the liquid level control of equipment, but also causes uneven fixing, and the fabric at the liquid level is in contact with foam instead of solution, resulting in color difference and uneven fastness. In addition, high-concentration polymers are more likely to react strongly with residual anionic substances in the dye bath, resulting in precipitation and causing cylinder or roller sticking, especially when the water hardness is high. SUMMARY

[0004] In order to solve the problems mentioned in the background, the present application provides a high-concentration formaldehyde-free fixing agent and a preparation method thereof.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme: A high-concentration formaldehyde-free fixing agent is prepared from the following raw materials by weight: 60-75 parts of dimethyl diallyl ammonium chloride solution, 1-7 parts of dicyandiamide derivative, 5-12 parts of N-vinyl pyrrolidone, 0.1-0.5 parts of initiator and 10-25 parts of deionized water.

[0006] Further, the mass percentage concentration of dimethyl diallyl ammonium chloride solution is 50-65%, and the anion charge requirement of the fixing agent is 600-700 μeq / L, the viscosity average molecular weight is 100-300 million, and the dynamic viscosity is 5000-15000 mPa·s.

[0007] Further, the initiator is a redox system, which is composed of sodium sulfite and ammonium persulfate, potassium persulfate or sodium persulfate in a molar ratio of 1:(1-1.1).

[0008] According to another aspect of the present application, a preparation method of the high-concentration formaldehyde-free fixing agent is provided, which comprises the following steps: S1, mixing deionized water and an initiator to prepare an initiator solution; S2, under the protection of nitrogen, adding 1 / 5-1 / 4 of the total mass of the dimethyldiallylammonium chloride solution to a reaction kettle, and stirring at a speed of 100-200 rpm to raise the temperature to 70-80℃; S3, adding the remaining dimethyldiallylammonium chloride solution, simultaneously adding a mixture of dicyandiamide derivative and N-vinylpyrrolidone, and synchronously adding 1 / 5 of the total amount of the initiator solution; S4, after the addition is completed, raising the temperature to 85-95℃, and maintaining the temperature for 0.5-1 h; S5, adding 2 / 5 of the total amount of the initiator solution, maintaining the temperature for 2-3 h, and then raising the temperature to 95-105℃; S6, adding 2 / 5 of the total amount of the initiator solution, maintaining the temperature for 2-3 h, and then lowering the temperature to 40-45℃ to discharge the product.

[0009] Further, in step S3, the remaining dimethyldiallylammonium chloride solution is added for 1-3 h, the mixture of dicyandiamide derivative and N-vinylpyrrolidone is added for 0.5-1 h, and the initiator solution is added for the first time for 2-4 h.

[0010] Further, the preparation method of the dicyandiamide derivative comprises the following steps: A1, reacting dicyandiamide and chloroacetonitrile in an ethyl acetate / water mixed solvent under the catalysis of tetrabutylammonium bromide to obtain 1-cyano-2-dicyandiamide ethane; A2, hydrolyzing the product in step A1 in a NaOH aqueous solution, and then acidifying to precipitate 3-amino-3-dicyandiamide propionic acid; A3, esterifying 3-amino-3-dicyandiamide propionic acid with hydroxyalkyl acrylate under the catalysis of N,N'-dicyclohexyl carbodiimide, and then purifying to obtain the dicyandiamide derivative.

[0011] Further, in step A1, the pH value is controlled to be 8-9, the temperature is controlled to be 58-62℃, and the volume ratio of ethyl acetate / water is (2-3):1, and in step A2, the pH value at the end of acidification is 2-2.5.

[0012] Further, the hydroxyalkyl acrylate in step A3 is selected from one of the following compounds: hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 4-hydroxybutyl methacrylate or 4-hydroxybutyl acrylate, the esterification reaction temperature is 10-25℃, and the solvent is anhydrous tetrahydrofuran.

[0013] According to another aspect of the present application, the application of the above high-concentration formaldehyde-free fixing agent in textile dyeing is provided, and the fixing treatment conditions are as follows: the fixing agent dosage is 1-3% (o.w.f), the pH value is 5-7, the temperature is 40-45℃, the time is 20-30min, and the bath ratio is 1:10.

[0014] The present application has the following beneficial effects: 1. The dicyandiamide group (-NH-C (=NH)-NH-CN) in the dicyandiamide derivative molecule can form a strong hydrogen bond network with anionic dyes, and the unsaturated double bond in the acrylate structure can copolymerize with dimethyldiallylammonium chloride during polymerization to form a polymer backbone with high positive charge density. Through electrostatic attraction, the dicyandiamide group can efficiently adsorb dye anions, and through multivalent hydrogen bonding with sulfonic acid groups and hydroxyl groups in the dye molecule, a synergistic anchoring effect is formed, which significantly reduces the desorption rate of the dye from the fiber. The acid and sweat stain color fastness of the dyed fabric treated with the fixing agent of the present application can reach 4.5-4.8, and the staining fastness can reach 4.0-4.5, which is significantly better than the scheme without adding dicyandiamide derivatives, effectively improving the insufficient color fastness of traditional formaldehyde-free fixing agents in sweat environments, and significantly improving the wet rubbing fastness and sweat fastness.

[0015] 2. The introduction of N-vinyl pyrrolidone significantly reduces the surface tension of the system, and its lactam structure cooperates with the dicyandiamide derivative to inhibit the micellization trend of the polyquaternary ammonium salt segment in the aqueous phase. At the same time, its hydrophilic branch promotes the penetration of the fixing agent into the fiber interior, forming a dense and uniform cationic film layer at the fiber / dye interface. The foam decay rate of the fixing agent of the present application is 67.3-74.7%, which can not only reduce the foam generation during high-speed stirring or overflow application, avoiding the problems of uneven fixing and color difference caused by foam, but also avoid the precipitation and roller sticking problems caused by local charge supersaturation of traditional high-concentration fixing agents, and improve the stable foam generation and reaction precipitation with anionic substances in the dye bath of high-concentration formaldehyde-free fixing agents.

[0016] 3、The application adopts sodium sulfite / persulfate redox initiation system, and polymerization is carried out at 70-105℃ gradient control temperature, so that the hydrolysis side reaction of dicyandiamide group at high temperature is effectively inhibited, the stability of product viscosity average molecular weight and negative charge demand is guaranteed, the high reaction activity of the color fixing agent is maintained at low temperature of 40-45℃, high efficiency color fixing can be realized without high temperature, energy consumption is reduced, damage to textile fibers caused by high temperature is avoided, and the influence of side reaction in the polymerization process on the performance stability of the color fixing agent is avoided.

[0017] 4、The color fixing agent prepared in the application still maintains the flowability of 5000-15000mPa・s dynamic viscosity at high concentration, avoids the easy gelation of high concentration polymer, and does not contain harmful substances such as formaldehyde and APEO, so as to avoid the risk of releasing formaldehyde and harming human health of traditional formaldehyde-containing color fixing agents, meet the environmental protection requirements, and meet the green processing demand of textiles. DETAILED DESCRIPTION

[0018] The technical solutions of the application will be described below in combination with the embodiments of the application. Obviously, the described embodiments are part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0019] The application provides a high-concentration formaldehyde-free color fixing agent, which is preferably prepared from the following raw materials in parts by weight: dimethyl diallyl ammonium chloride solution 60-75 parts, dicyandiamide derivative 1-7 parts, N-vinyl pyrrolidone 5-12 parts, initiator 0.1-0.5 parts and deionized water 10-25 parts.

[0020] More preferably, it is prepared from the following raw materials in parts by weight: dimethyl diallyl ammonium chloride solution 65-72 parts, dicyandiamide derivative 3-5 parts, N-vinyl pyrrolidone 7-10 parts, initiator 0.2-0.3 parts and deionized water 18-23 parts.

[0021] In the high-concentration formaldehyde-free color fixing agent provided by the application, the mass percentage concentration of the dimethyl diallyl ammonium chloride solution is preferably 50-65%, and can be 50%, 52%, 55%, 58%, 60%, 61%, 62% and 65% in particular.

[0022] The anion charge requirement of the high-concentration formaldehyde-free fixing agent is preferably 600-700 mu eq / L, and can be 600 mu eq / L, 610 mu eq / L, 620 mu eq / L, 630 mu eq / L, 640 mu eq / L, 650 mu eq / L, 660 mu eq / L, 670 mu eq / L, 680 mu eq / L, 690 mu eq / L, and 700 mu eq / L.

[0023] The viscosity average molecular weight of the high-concentration formaldehyde-free fixing agent is preferably 100-300 million, and can be 100 million, 200 million, and 300 million.

[0024] The dynamic viscosity of the high-concentration formaldehyde-free fixing agent is preferably 5000-15000 mPa·s, and can be 5000 mPa·s, 6000 mPa·s, 7000 mPa·s, 8000 mPa·s, 10000 mPa·s, 12000 mPa·s, and 15000 mPa·s.

[0025] The initiator of the high-concentration formaldehyde-free fixing agent is a redox system composed of sodium sulfite and ammonium persulfate, potassium persulfate, or sodium persulfate, and can be sodium sulfite and ammonium persulfate, sodium sulfite and potassium persulfate, or sodium sulfite and sodium persulfate, with a molar ratio of 1: (1-1.1), and can be 1:1, 1:1.01, 1:1.02, 1:1.05, 1:1.08, and 1:1.1.

[0026] The application further provides a preparation method of the high-concentration formaldehyde-free fixing agent. S1, mixing deionized water and an initiator according to weight fractions to prepare an initiator solution; S2, under nitrogen protection, adding 1 / 5-1 / 4 of the total mass of the dimethyldiallylammonium chloride solution to a reaction kettle, and stirring at a speed of 100-200 rpm to heat to 70-80 DEG C; S3, adding the remaining dimethyldiallylammonium chloride solution, simultaneously adding a mixture of dicyandiamide derivative and N-vinylpyrrolidone, and synchronously adding 1 / 5 of the total amount of the initiator solution; S4, after the addition is completed, heating to 85-95 DEG C, and keeping the temperature for 0.5-1 h; S5, adding 2 / 5 of the total amount of the initiator solution, keeping the temperature for 2-3 h, and then heating to 95-105 DEG C; S6, adding the remaining initiator solution, keeping the temperature for 2-3 h, and then cooling to 40-45 DEG C to discharge.

[0027] In the preparation method, 1 / 5-1 / 4 of the total mass of the dimethyldiallylammonium chloride solution is added in step S2, and can be 1 / 5 and 1 / 4.

[0028] In the preparation method provided by the application, the stirring speed in step S2 is preferably 100-200 rpm, and can be specifically 100 rpm, 150 rpm or 200 rpm; and the temperature for temperature rising is preferably 70-80℃, and can be specifically 70℃, 71℃, 72℃, 73℃, 74℃, 75℃, 76℃, 77℃, 78℃, 79℃ or 80℃.

[0029] In the preparation method provided by the application, the temperature for temperature rising in step S4 is preferably 85-95℃, and can be specifically 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃ or 95℃; and the temperature holding time is preferably 0.5-1h, and can be specifically 0.5h, 0.6h, 0.7h, 0.8h or 1h.

[0030] In the preparation method provided by the application, the temperature holding time in step S5 is preferably 2-3h, and can be specifically 2h, 2.2h, 2.4h, 2.5h, 2.6h, 2.8h or 3h; and the temperature for temperature rising is preferably 95-105℃, and can be specifically 95℃, 96℃, 97℃, 98℃, 99℃, 100℃, 101℃, 102℃, 103℃, 104℃ or 105℃.

[0031] In the preparation method provided by the application, the temperature holding time in step S6 is preferably 2-3h, and can be specifically 2h, 2.2h, 2.4h, 2.5h, 2.6h, 2.8h or 3h; and the temperature for temperature lowering is preferably 40℃, 41℃, 42℃, 43℃, 44℃ or 45℃.

[0032] In the preparation method provided by the application, the preparation method of the dicyandiamide derivative comprises the following steps: A1, reacting dicyandiamide with chloroacetonitrile in an ethyl acetate / water mixed solvent under the catalysis of tetrabutylammonium bromide to obtain 1-cyano-2-dicyandiamide ethane; A2, hydrolyzing the product in step A1 in a NaOH aqueous solution, and precipitating 3-amino-3-dicyandiamide propionic acid after acidification; A3, esterifying 3-amino-3-dicyandiamide propionic acid with hydroxyalkyl acrylate under the catalysis of N,N'-dicyclohexyl carbodiimide, and obtaining the dicyandiamide derivative after purification.

[0033] In the preparation method provided by the application, the pH value during the reaction in step A1 is preferably 8.0-9.0, and can be specifically 8.0, 8.1, 8.2, 8.5, 8.6, 8.8 or 9.0.

[0034] In the preparation method provided by the application, the temperature in the reaction in step A1 is preferably 58-62℃, and can be specifically 58℃, 59℃, 60℃, 61℃ and 62℃.

[0035] In the preparation method provided by the application, the volume ratio of ethyl acetate / water in step A1 is preferably (2-3):1, and can be specifically 2:1, 2.2:1, 2.4:1, 2.5:1, 2.6:1, 2.8:1 and 3:1.

[0036] In the preparation method provided by the application, the acidification end point pH value in step A2 is preferably 2.0-2.5, and can be specifically 2.0, 2.1, 2.2, 2.3, 2.4 and 2.5.

[0037] In the preparation method provided by the application, the concentration of the aqueous NaOH solution in step A2 is preferably 0.1-0.5 mol / L, and can be specifically 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L and 0.5 mol / L.

[0038] In the preparation method provided by the application, the hydroxyalkyl acrylate in step A3 is selected from one of the following compounds: hydroxyethyl methacrylate (CAS No.: 868-77-9), hydroxyethyl acrylate (CAS No.: 818-61-1), hydroxypropyl methacrylate (CAS No.: 27813-02-1), hydroxypropyl acrylate (CAS No.: 25584-83-2), 4-hydroxybutyl methacrylate (CAS No.: 997-46-6) or 4-hydroxybutyl acrylate (CAS No.: 2478-10-6), and the solvent is anhydrous tetrahydrofuran.

[0039] In the preparation method provided by the application, the temperature of the reaction in step A3 is preferably 10-25℃, and can be specifically 10℃, 15℃, 20℃ and 25℃.

[0040] The application also provides a use of the high-concentration formaldehyde-free fixing agent in textile dyeing. The fixing agent is preferably used in an amount of 1-3% (o.w.f), and can be specifically 1% (o.w.f), 2% (o.w.f) and 3% (o.w.f).

[0041] The pH value is preferably 5.0-7.0, and can be specifically 5.0, 5.5, 6.0, 6.5 and 7.0.

[0042] The temperature is preferably 40-45℃, and can be specifically 40℃, 41℃, 42℃, 43℃, 44℃ and 45℃.

[0043] The time is preferably 20-30 min, and can be specifically 20 min, 25 min and 30 min.

[0044] The bath ratio is preferably 1:10.

[0045] For a clearer understanding, the following examples and comparative examples are described in detail below. Example 1

[0046] B1, 84.08 g of dicyandiamide, 81.16 g of chloroacetonitrile, and 6.45 g of tetrabutylammonium bromide were added to a reactor previously charged with 900 g of a mixture of ethyl acetate / water in a volume ratio of 2:1, the pH was adjusted to 8.0, and the reaction was carried out at 58°C for 2 h to obtain 1-cyano-2-dicyandiamidinoethane.

[0047] B2, the reaction solution in step B1 was transferred to a hydrolysis kettle, 500 g of 0.1 mol / L NaOH aqueous solution was added, and the temperature was raised to 70°C for hydrolysis for 4 h. After the reaction was completed, the temperature was cooled to 25°C, the pH was adjusted to 2.0, and white solids were precipitated. After filtration, washing with water, and drying, 3-amino-3-dicyandiamidinopropionic acid was obtained.

[0048] B3, 125.0 g of 3-amino-3-dicyandiamidinopropionic acid, 130.14 g of hydroxyethyl acrylate, and 24.5 g of N,N'-dicyclohexyl carbodiimide were added to 500 g of anhydrous tetrahydrofuran, and the mixture was stirred at 10°C for 12 h. The filtrate was concentrated and recrystallized from ethanol to obtain a dicyandiamide derivative.

[0049] B4, an initiator solution was prepared by mixing 10 parts of deionized water and 0.1 parts of a mixture of sodium sulfite and potassium persulfate in a molar ratio of 1:1.

[0050] B5, under nitrogen protection, 12 parts of a 50% mass percentage dimethyl diallyl ammonium chloride solution was added to the reaction kettle, and the temperature was raised to 70°C with stirring at a speed of 100 rpm.

[0051] B6, the remaining 48 parts of the dimethyl diallyl ammonium chloride solution was started to be added, and at the same time, 1 part of a mixture of the dicyandiamide derivative and 5 parts of N-vinyl pyrrolidone was added, and 1 / 5 of the total amount of the initiator solution was added synchronously.

[0052] B7, after the addition was completed, the temperature was raised to 85°C, and the temperature was maintained for 0.5 h.

[0053] B8, 2 / 5 of the total amount of the initiator solution was added, and the temperature was maintained for 2 h, and then the temperature was raised to 95°C.

[0054] B9, the remaining initiator solution was added, the temperature was maintained for 2 h, and then the temperature was lowered to 40°C to discharge the product. Example 2

[0055] B1, 84.08 g of dicyandiamide, 81.16 g of chloroacetonitrile and 6.45 g of tetrabutylammonium bromide were added to a reactor previously charged with 900 g of a mixture of ethyl acetate / water in a volume ratio of 2.5:1, the pH value was adjusted to 8.5, and reaction was carried out at 60°C for 2.5 h to obtain 1-cyano-2-dicyanamidoethane.

[0056] B2, the reaction solution in step B1 was transferred to a hydrolysis kettle, 500 g of 0.2 mol / L NaOH aqueous solution was added, and the temperature was raised to 70°C for hydrolysis for 4 h. After the reaction was completed, the temperature was cooled to 25°C, the pH was adjusted to 2.3, and white solids were precipitated. After filtration, washing and drying, 3-amino-3-dicyanamidopropionic acid was obtained.

[0057] B3, 125.0 g of 3-amino-3-dicyanamidopropionic acid, 142.15 g of hydroxyethyl methacrylate and 24.5 g of N,N'-dicyclohexyl carbodiimide were added to 500 g of anhydrous tetrahydrofuran, and reaction was carried out at 15°C for 12 h. After filtration and concentration, ethanol recrystallization was carried out to obtain a dicyandiamide derivative.

[0058] B4, an initiator solution was prepared by mixing 18 parts of deionized water and 0.2 parts of sodium sulfite and ammonium persulfate in a molar ratio of 1:1.02.

[0059] B5, under nitrogen protection, 13 parts of a 55% mass percentage dimethyl diallyl ammonium chloride solution was added to the reaction kettle, and the temperature was raised to 72°C with stirring at a speed of 150 rpm.

[0060] B6, the remaining 52 parts of dimethyl diallyl ammonium chloride solution was started to be added, while 3 parts of a mixture of dicyandiamide derivative and 7 parts of N-vinyl pyrrolidone was added, and 1 / 5 of the total amount of initiator solution was added synchronously.

[0061] B7, after the addition was completed, the temperature was raised to 87°C, and the temperature was kept for 0.6 h.

[0062] B8, 2 / 5 of the total amount of initiator solution was added, and the temperature was kept for 2.2 h, and then the temperature was raised to 97°C.

[0063] B9, the remaining initiator solution was added, the temperature was kept for 2.2 h, and then the temperature was lowered to 41°C to discharge. Example 3

[0064] B1, 84.08 g of dicyandiamide, 81.16 g of chloroacetonitrile and 6.45 g of tetrabutylammonium bromide were added to a reactor previously charged with 900 g of a mixture of ethyl acetate / water in a volume ratio of 2.5:1, the pH value was adjusted to 8.8, and reaction was carried out at 61°C for 2.5 h to obtain 1-cyano-2-dicyanamidoethane.

[0065] B2, transfer the reaction solution in step B1 to a hydrolysis kettle, add 500 g of 0.4 mol / L NaOH aqueous solution, and hydrolyze at 70℃ for 4 h. After the reaction is completed, cool to 25℃, adjust the pH to 2.4, and precipitate white solids. After suction filtration, water washing, and drying, 3-amino-3-dicyanamidopropionic acid is obtained.

[0066] B3, add 125.0 g of 3-amino-3-dicyanamidopropionic acid, 144.17 g of hydroxypropyl acrylate, and 24.5 g of N,N'-dicyclohexyl carbodiimide into 500 g of anhydrous tetrahydrofuran, and react at 20℃ for 12 h. After filtration and concentration, ethanol recrystallization is performed to obtain a dicyanamide derivative.

[0067] B4, prepare an initiator solution by mixing 20 parts of deionized water and 0.4 parts of sodium sulfite and sodium persulfate in a molar ratio of 1:1.05.

[0068] B5, under nitrogen protection, add 17.5 parts of a 62% mass percentage dimethyl diallyl ammonium chloride solution to the reaction kettle, and stir at a speed of 150 rpm to warm up to 78℃.

[0069] B6, start adding the remaining 52.5 parts of the dimethyl diallyl ammonium chloride solution, while adding 6 parts of a mixture of the dicyanamide derivative and 10 parts of N-vinyl pyrrolidone, and synchronously adding 1 / 5 of the total amount of the initiator solution.

[0070] B7, after the addition is completed, warm up to 92℃, and keep for 0.8 h.

[0071] B8, add 2 / 5 of the total amount of the initiator solution, keep for 2.5 h, and then warm up to 102℃.

[0072] B9, add the remaining initiator solution, keep for 2.5 h, and then cool down to 44℃ to discharge. Example 4

[0073] B1, add 84.08 g of dicyanamide, 81.16 g of chloroacetonitrile, and 6.45 g of tetrabutylammonium bromide to a reactor pre-charged with 900 g of a mixed solvent of ethyl acetate / water in a volume ratio of 3:1, adjust the pH value to 9.0, and react at 62℃ for 3 h to obtain 1-cyano-2-dicyanamidoethane.

[0074] B2, transfer the reaction solution in step B1 to a hydrolysis kettle, add 500 g of 0.5 mol / L NaOH aqueous solution, and hydrolyze at 70℃ for 4 h. After the reaction is completed, cool to 25℃, adjust the pH to 2.5, and precipitate white solids. After suction filtration, water washing, and drying, 3-amino-3-dicyanamidopropionic acid is obtained.

[0075] B3, 125.0 g of 3-amino-3-dicyandiamide propionic acid, 158.20 g of 4-hydroxybutyl acrylate and 24.5 g of N,N'-dicyclohexyl carbodiimide were added into 500 g of anhydrous tetrahydrofuran, reacted at 25 °C for 12 h, filtered and concentrated, and recrystallized with ethanol to obtain a dicyandiamide derivative.

[0076] B4, an initiator solution was prepared by mixing 25 parts of deionized water and 0.5 parts of sodium sulfite and sodium persulfate with a molar ratio of 1:1.1.

[0077] B5, under the protection of nitrogen, 15 parts of a 65% mass percentage dimethyl diallyl ammonium chloride solution was added to the reaction kettle, and the temperature was raised to 80 °C with stirring at a speed of 200 rpm.

[0078] B6, the remaining 60 parts of the dimethyl diallyl ammonium chloride solution was started to be added, while 7 parts of a mixture of dicyandiamide derivative and 12 parts of N-vinyl pyrrolidone was added, and 1 / 5 of the total amount of initiator solution was added synchronously.

[0079] B7, after the addition was completed, the temperature was raised to 95 °C and kept for 1 h.

[0080] B8, 2 / 5 of the total amount of initiator solution was added, kept for 3 h, and the temperature was raised to 105 °C.

[0081] B9, the remaining initiator solution was added, kept for 3 h, and the temperature was lowered to 45 °C to discharge.

[0082] Comparative Example 1 The difference between this comparative example and Example 1 is that no dicyandiamide derivative is added, and the remaining steps are the same as those of Example 1.

[0083] Comparative Example 2 The difference between this comparative example and Example 2 is that no N-vinyl pyrrolidone is added, and the remaining steps are the same as those of Example 2.

[0084] A pure cotton fabric was immersed in a dye bath containing 2% o.w.f C.I. Reactive Red 195, with a bath ratio of 1:20, dyed at 60 °C for 40 min, washed, soaped at 95 °C for 10 min, washed with cold water, and dried at 60 °C. 2 g of the fixing agent prepared in Examples 1-4 and Comparative Examples 1-2 was added to deionized water containing 0.1 mol / L of acetic acid-sodium acetate buffer with a pH of 6.0, and the volume was made up to 200 mL. 20 g of dyed fabric was placed in the fixing bath, and the timer was started at 45 °C, and the temperature was raised to 45 °C at a rate of 2 °C / min, and constant temperature oscillation was carried out at 120 rpm for 25 min. The fabric was removed, washed with cold water to neutralize, and dried at 60 °C.

[0085] The acid sweat fastness test was carried out according to ISO 105-E04 Textiles - Colour fastness tests - Part E04: Fastness to perspiration - Acid. First, artificial acid sweat was prepared, and the components were as follows: L-histidine hydrochloride 0.5 g / L, sodium chloride 5 g / L, sodium dihydrogen phosphate dihydrate 2.2 g / L, and the pH value was adjusted to 5.5 ± 0.2 with 0.1 mol / L NaOH.

[0086] The dyed cloth treated in Examples 1-4 and Comparative Examples 1-2 was cut into 10 x 4 cm and sewn with multi-fiber lining cloth. It was immersed in artificial acid sweat (bath ratio 1:50) and wetted at room temperature for 30 min. The sample was taken out, clamped between two acrylic plates, and a pressure of 12.5 kPa was applied. It was placed in a sweat fastness tester and treated at 37 ± 2°C for 4 h and dried in an oven at 60°C for 4 h. The color change and staining were evaluated using a gray scale card compared with the original sample. The results are shown in Table 1: Table 1 Results of acid sweat fastness test

[0087] The foam height test was carried out according to ASTM D3519-88 (2002) Standard Test Method for Foam in Aqueous Medium (Stirrer Test). The fixing agent prepared in Examples 1-4 and Comparative Examples 1-2 was respectively prepared into a 1 g / L fixing agent solution with deionized water. 500 mL of the fixing agent test solution was preheated to 40 ± 1°C, and 200 mL of the test solution was poured into a graduated cylinder containing 50 mL of the same concentration liquid from a height of 90 cm. The liquid level to the top of the foam was immediately recorded as the initial foam height H0 (mL). After standing for 10 min, the residual foam height Hr (mL) was recorded, and the foam decay rate was calculated according to the following formula: 10

[0088] The results are shown in Table 2: Table 2 Results of fixing agent foam performance test

[0089] As can be seen from Table 1, the color change fastness of Examples 1-4 is 4.5-4.8, and the staining fastness is 4.0-4.5, indicating that the dyed cloth treated with the fixing agent prepared in these examples has good acid sweat fastness. In the examples, a fixing agent containing a dicyandiamide structure and copolymerized with other monomers was prepared through a series of reactions. The nitrogen atom in the dicyandiamide structure has a lone pair of electrons, which can form hydrogen bonds or coordination bonds with certain groups in the dye molecule, enhancing the binding force between the dye and the fiber, making the dye more firmly attached to the fiber, so that the dye is not easily detached in an acid sweat environment, improving the color change fastness and staining fastness.

[0090] ​Meanwhile, monomers such as N-vinyl pyrrolidone and dimethyldiallylammonium chloride are added in the examples to copolymerize, forming a polymer with good film-forming properties. A uniform thin film is formed on the surface of the dyed fabric, which can prevent the dissolution and diffusion of dye molecules in sweat, further improving the acid perspiration fastness.

[0091] The color change fastness of Comparative Example 1 is 3.2, and the staining fastness is 2.5, which is significantly lower than the examples. This is because the lack of dicyandiamide structure cannot form the above hydrogen bond or coordination bond with the dye molecules, and cannot effectively enhance the binding force between the dye and the fiber. Under the action of acid perspiration, the dye is easily detached from the fiber, resulting in a decrease in color fastness.

[0092] The color change fastness of Comparative Example 2 is 3.8, and the staining fastness is 3.0, which is also lower than the examples. This shows that N-vinyl pyrrolidone plays an important role in the fixing agent. The film-forming property of the polymer formed by copolymerization is affected, which cannot effectively prevent the dissolution and diffusion of dye molecules in sweat, thereby reducing the acid perspiration fastness.

[0093] As can be seen from Table 2, the foam decay rate of Examples 1-4 is 67.3-74.7%, indicating that these fixing agents have good defoaming performance. This may be because the molecular structure of the fixing agent prepared in the examples has a certain surface activity, but the intermolecular force is relatively weak. After the formation of foam, the molecules are easily rearranged and moved at the gas-liquid interface, making the foam wall thin and the foam easy to break, thereby having a high foam decay rate. For example, the foam decay rate of Example 1 is 74.7%, indicating that its molecular structure is not conducive to the long-term existence of foam in terms of foam formation and stability.

[0094] The foam decay rate of Comparative Example 1 is 50.0%, which is lower than the examples. This may be due to the lack of dicyandiamide derivative, which changes the molecular structure and surface activity of the fixing agent, increases the intermolecular force, and makes the foam wall relatively stable and not easy to break, resulting in a decrease in foam decay rate.

[0095] The foam decay rate of Comparative Example 2 is only 24.6%, which is much lower than the examples. The lack of N-vinyl pyrrolidone in the fixing agent may result in a lack of some groups or structures in the fixing agent molecules that can destroy the stability of the foam, and the molecules are more closely and orderly arranged at the gas-liquid interface, forming more stable foam that is difficult to break, so the foam decay rate is very low.

[0096] In summary, Examples 1-4 have good comprehensive performance in acid perspiration fastness and foam performance by reasonable selection of raw materials and control of reaction conditions.

[0097] In the description of the specification, the description of the terms "embodiment", "comparative example", "each embodiment" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or comparative example are included in at least one embodiment or comparative example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or comparative example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or comparative examples in an appropriate manner.

[0098] The above description is merely preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes to the technical solutions and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A high-concentration, formaldehyde-free color-fixing agent, characterized in that, It is prepared from the following raw materials in parts by weight: The solution contains 60-75 parts of dimethyl diallyl ammonium chloride, 1-7 parts of dicyandiamide derivative, 5-12 parts of N-vinylpyrrolidone, 0.1-0.5 parts of initiator, and 10-25 parts of deionized water.

2. The high-concentration formaldehyde-free fixing agent according to claim 1, characterized in that, The mass percentage concentration of the dimethyl diallyl ammonium chloride solution is 50-65%, and the required negative charge of the fixing agent is 600-700 μeq / L, the viscosity-average molecular weight is 100,000-300,000, and the dynamic viscosity is 5,000-15,000 mPa·s.

3. The high-concentration formaldehyde-free fixing agent according to claim 1, characterized in that, The initiator is a redox system, consisting of sodium sulfite and ammonium persulfate, potassium persulfate, or sodium persulfate in a molar ratio of 1:(1-1.1).

4. A method for preparing the high-concentration formaldehyde-free fixing agent according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Mix deionized water and initiator to prepare initiator solution; S2. Under nitrogen protection, add 1 / 5 to 1 / 4 of the total mass of dimethyl diallyl ammonium chloride solution to the reactor, and stir and heat to 70-80℃; S3. Add the remaining dimethyl diallyl ammonium chloride solution, along with a mixture of dicyandiamide derivative and N-vinylpyrrolidone, and simultaneously add 1 / 5 of the total initiator solution. S4. After adding the ingredients, raise the temperature to 85-95℃ and keep it warm for 0.5-1 hour. S5. Add 2 / 5 of the total amount of initiator solution, keep warm for 2-3 hours, and then raise the temperature to 95-105℃; S6. Add 2 / 5 of the total amount of initiator solution, keep warm for 2-3 hours, and then discharge the material at 40-45℃.

5. The preparation method according to claim 4, characterized in that, In step S3, the remaining dimethyl diallyl ammonium chloride solution is added at a time of 1-3 hours, the mixture of dicyandiamide derivative and N-vinylpyrrolidone is added at a time of 0.5-1 hours, and the initiator solution is added for the first time at a time of 2-4 hours.

6. The preparation method according to claim 4, characterized in that, The preparation method of dicyandiamide derivatives includes the following steps: A1. Dicyandiamide and chloroacetonitrile were reacted in a mixed solvent of ethyl acetate / water under the catalysis of tetrabutylammonium bromide to obtain 1-cyano-2-dicyandiamide ethane; A2. Hydrolyze the product from step A1 in NaOH aqueous solution, and after acidification, 3-amino-3-dicyandiamide propionic acid is precipitated. A3. 3-Amino-3-dicyandiamide propionic acid was esterified with hydroxyalkyl acrylate under the catalysis of N,N'-dicyclohexylcarbodiimide, and the resulting dicyandiamide derivative was purified.

7. The preparation method according to claim 6, characterized in that, In step A1, the pH value is controlled at 8-9, the temperature at 58-62℃, and the volume ratio of ethyl acetate to water is (2-3):

1. In step A2, the pH value at the acidification endpoint is 2-2.

5.

8. The preparation method according to claim 6, characterized in that, In step A3, the hydroxyalkyl acrylate is selected from one of the following compounds: hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl methacrylate, hydroxypropyl acrylate, 4-hydroxybutyl methacrylate, or 4-hydroxybutyl acrylate, and the esterification reaction temperature is 10-25℃.

9. The application of the high-concentration formaldehyde-free fixing agent according to any one of claims 1-3 in textile dyeing, characterized in that, The conditions for color fixing are as follows: the amount of color fixing agent is 1-3% (owf), the pH value is 5-7, the temperature is 40-45℃, the time is 20-30min, and the liquor ratio is 1:10.

Images