Low-temperature fabric bleaching agent

Abstract

The invention relates to a low-temperature fabric bleaching agent. The fabric bleaching agent comprises an acetylated cationic starch activating agent. The activating agent adopts green and environment-friendly natural starch as a raw material, the preparation method is simple, the yield is high, large-scale production can be achieved, and the cationic starch activating agent has good bleaching promoting performance on the cotton fabric, is suitable for industrial popularization and has important application prospects in the aspect of developing a new hydrogen peroxide low-temperature bleaching process of the cotton fabric.

Description

Technical Field

[0001] The invention belongs to the field of fabric bleaching, and particularly relates to a fabric bleaching agent. Background Art

[0002] Cotton fibers usually need to go through a pre-treatment bleaching process to remove natural impurities such as pigments to meet the requirements of textile processing. Bleaching with hydrogen peroxide is currently a widely used process. The traditional hydrogen peroxide bleaching process is a high-energy, high-temperature (98°C) and strong alkaline (pH>12NaOH) process. Under the current national "dual carbon goals", in order to meet the urgent needs of energy conservation and emission reduction in the textile industry, it is urgent to develop a low-temperature, weak-alkali ecological bleaching process. Using an activator to activate hydrogen peroxide is an important way to develop a low-temperature, weak-alkali bleaching process for cotton fabrics. However, there are still problems such as high bleaching temperature (>70°C), strong alkalinity (pH>10), poor water solubility of the activator, and poor biodegradability. Summary of the invention

[0003] In view of the defects of the prior art, the technical problem to be solved by the present invention is to provide a low-temperature fabric bleaching agent. The present invention uses natural starch as a green raw material, designs and synthesizes a cationic starch activator with excellent water solubility, which can activate hydrogen peroxide to pre-treat cotton fabrics under low temperature (50°C) and low alkali (pH=8NaHCO3) process conditions, obtains good bleaching effect, and has industrial application prospects.

[0004] The invention provides a hydrogen peroxide activator, which comprises an acetylated cationic starch activator.

[0005] The present invention provides a fabric bleaching agent, which comprises an acetylated cationic starch activator.

[0006] Preferably, the fabric bleaching agent further comprises hydrogen peroxide; wherein, by weight, the fabric bleaching agent comprises 5-30 parts of acetylated cationic starch activator and 4-8 parts of hydrogen peroxide.

[0007] Further preferably, the fabric bleaching agent further contains sodium bicarbonate, a refining agent, a penetrant and a stabilizer; wherein, by weight, the fabric bleaching agent comprises: 5-30 parts of acetylated cationic starch activator, 4-8 parts of hydrogen peroxide, 3-10 parts of sodium bicarbonate, 1-3 parts of refining agent, 1-3 parts of penetrant, and 0.1-1 part of stabilizer.

[0008] The refining agent is 1310; the penetrant is JFC; and the stabilizer is PASP.

[0009] Preferably, the preparation method of the acetylated cationic starch activator comprises:

[0010] (1) starch, sodium hydroxide aqueous solution, and 2,3-epoxypropyltrimethylammonium chloride aqueous solution are mixed, reacted, purified, and dried to obtain cationic starch;

[0011] (2) Cationic starch and acetic anhydride are mixed, and then sodium hydroxide solution is added dropwise, reacted, purified, and dried to obtain an acetylated cationic starch activator.

[0012] Preferably, in step (1), the ratio of starch, 2,3-epoxypropyltrimethylammonium chloride, sodium hydroxide and water is 5-10 g: 5-12 g: 5-10 g: 15-50 mL; and the concentration of the sodium hydroxide aqueous solution is 0.1-0.5 mol / L.

[0013] Preferably, in the step (1), the reaction temperature is 50-80° C. and the reaction time is 1-5 h. The purification is to adjust the solution pH to 6-7 with acetic acid after the reaction and to precipitate the cationic starch solid with ethanol. The drying is to dry for 10-12 h and then freeze-dry for 24-48 h.

[0014] Step (1) purification: the reaction solution was cooled to room temperature, the pH was adjusted to 6-7 with acetic acid, and ethanol was added to precipitate a light yellow solid.

[0015] Preferably, in step (2), the ratio of cationic starch, acetic anhydride and sodium hydroxide solution is 10-50 g:40-100 mL:1-6 mL; and the concentration of the sodium hydroxide solution is 10-15 mol / L.

[0016] Preferably, in the step (2), the reaction temperature is 50-70°C and the reaction time is 12-24h; the purification is performed by cooling the reaction solution to room temperature, pouring it into a mixed solution of ethanol and petroleum ether, letting it stand, and filtering to obtain a yellow solid, wherein the volume ratio of ethanol to petroleum ether is 1-1.5mL:2mL; and the drying is performed at 60°C for 24-48h.

[0017] Preferably, the refining agent is 1310; the penetrant is JFC; and the stabilizer is PASP.

[0018] The invention provides a fabric bleaching method, comprising: mixing any bleaching agent and water to obtain a bleaching solution, and then bleaching, washing and drying the fabric in the bleaching solution.

[0019] Preferably, the bleaching temperature is 40-60°C, the time is 1-2h; the ratio of the fabric to the bleaching solution is 1g:10-30mL; the fabric is cotton fabric or cotton grey cloth; the pH of the bleaching solution is 7.5-8.5.

[0020] Preferably, the bleaching liquid comprises 5-30 g / L acetylated cationic starch, 4-8 g / L 30% hydrogen peroxide, 3-10 g / L sodium bicarbonate, 1-3 g / L refining agent, 1-3 g / L penetrant, and 0.1-1 g / L stabilizer.

[0021] The bleaching is carried out by shaking on a dyeing machine at a temperature of 40-60° C. for 1-2 hours.

[0022] The present invention provides a method for preparing a hydrogen peroxide activator using green natural starch as a raw material. The cationic starch activator of the present invention has a simple preparation process, high yield, good water solubility, abundant starch raw material sources, good biodegradability, excellent low-temperature activation performance of the activator, is suitable for industrial promotion, and has important application prospects in developing low-temperature and low-alkali ecological bleaching processes for cotton fabrics.

[0023] The cationic starch activator of the present invention is firstly reacted with starch and 2,3-epoxypropyltrimethylammonium chloride, and then reacted with acetic anhydride to obtain the same. The activator can activate hydrogen peroxide at a low temperature of 50°C to significantly improve the whiteness of cotton fabrics. The activator of the present invention uses green and environmentally friendly natural starch as raw material, has a simple preparation method, high yield, and can be mass-produced. The cationic starch activator has good bleaching performance for cotton fabrics, is suitable for industrial promotion, and has important application prospects in developing a new process for low-temperature bleaching of cotton fabrics with hydrogen peroxide.

[0024] Beneficial Effects

[0025] The invention overcomes the disadvantages of traditional hydrogen peroxide bleaching activators, such as water solubility, environmental unfriendliness, and high energy consumption when used under high-temperature strong alkali (>80°C and pH>10NaOH) process conditions. The cationic starch bleaching activator involved uses natural starch as a green raw material, has a simple preparation process, high yield, good water solubility, is suitable for industrial promotion, can significantly improve the whiteness of cotton fabrics under low-temperature weak alkali (50°C and pH=8NaHCO3) process conditions, and has important application prospects in the development of low-temperature and low-alkali hydrogen peroxide activators and new ecological bleaching processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The infrared spectra of acetylated cationic starch, cationic starch and starch in Examples 1 and 2;

[0027] Figure 2 is a graph showing the relationship between the amount of cationic starch activator used and fabric whiteness in Example 3;

[0028] Figure 3 This is a graph showing the change in bursting strength of the fabric before and after bleaching in Example 3. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0030] Related tests:

[0031] The infrared spectrum was tested on the Spectrum Two instrument of PE Company in the United States.

[0032] The colorimeter used for whiteness determination is Datacolor SF1000, the whiteness of the fabric is tested according to standard ASTME313-20, and the strength of the fabric is tested using an electronic fabric strength tester - bursting (model YG026Q) in accordance with national standard GB / T19976-2005.

[0033] The refining agent is 1310; the penetrant is JFC; and the stabilizer is PASP.

[0034] Example 1

[0035] Synthesis of Cationic Starch and Acetylated Cationic Starch Activator:

[0036] Disperse starch (10 g) in 25 mL sodium hydroxide solution (0.125 mol / L), heat to 60 °C in an oil bath, add 10 mL of 2,3-epoxypropyltrimethylammonium chloride aqueous solution (1.2 g / mL) under magnetic stirring, and continue to react for 4 hours. Cool to room temperature, adjust the solution to pH 6-7 with acetic acid, add 70 mL of ethanol, filter the precipitated solid, dry at 60 °C for 12 hours, and freeze-dry for 48 hours to obtain 14 g of cationic starch with a yield of 72%. The infrared spectrum of the cationic starch product is as follows Figure 1 Compared with the starch raw material, cationic starch has a -1 Cation appears at + The characteristic stretching vibration peak of CH in N(CH3)3 indicates that cationic starch has been successfully prepared.

[0037] Cationic starch (10 g) and acetic anhydride (40 mL) were mixed in a flask, and 1.25 mL of sodium hydroxide solution (12.5 mol / L) was added dropwise under magnetic stirring. The oil bath was heated to 60°C for 24 hours. After cooling to room temperature, the mixture was poured into 90 mL of ethanol-petroleum ether (volume ratio 1:2) and allowed to stand. The precipitated solid was filtered and dried at 60°C for 48 hours to obtain 13 g of acetylated cationic starch with a yield of 92%. The infrared spectrum of the acetylated cationic starch product is shown in FIG. Figure 1Compared with starch, acetylated cationic starch has a -1 A strong C=O carbonyl characteristic absorption peak appears at 1224 cm -1 The CO absorption peak in the carboxylate bond appears at 2979 cm -1 、2903cm -1 and 1372cm -1 The alkyl peak at 3300 cm -1 The alcohol hydroxyl peak in the starch raw material almost completely disappeared, indicating that the acetylated cationic starch has been successfully prepared.

[0038] Example 2

[0039] Application of acetylated cationic starch activator in activated hydrogen peroxide bleaching of cotton fabrics.

[0040] 5g of cotton fabric was immersed in 100ml of bleaching bath, wherein the bath contained the acetylated cationic starch activator (5-30g / L) synthesized in Example 1, 30% hydrogen peroxide (5g / L), 4g / L of sodium bicarbonate, 1g / L of refining agent, 1g / L of penetrant, and 0.5g / L of stabilizer. At this time, the pH value of the bleaching bath was 8, and the reaction was oscillated for 1 hour under the process condition of 50°C. After the reaction was completed, the cotton fabric was taken out, washed three times with distilled water, and then dried at room temperature, and the whiteness was tested. It can be seen that with the addition of acetylated cationic starch, the whiteness of the fabric increased. In the presence of 30g / L of acetylated cationic starch activator, the whiteness can reach 61.5 (such as Figure 2 By comparing the bursting strength of the fabric before and after bleaching, it can be found that the bursting strength of the fabric in the bleaching system with 30g / L acetylated starch activator added is 593.21, which retains more than 96% of the grey fabric (as shown in Figure 2). Figure 3 shown).

[0041] Example 3

[0042] Hydrogen peroxide bleaching of cotton fabric in the blank control group.

[0043] 5g of cotton fabric was immersed in 100ml of bleaching bath, which contained 30% hydrogen peroxide (5g / L), 4g / L of sodium bicarbonate, 1g / L of refining agent, 1g / L of penetrant, and 0.5g / L of stabilizer. The pH value of the bleaching bath was 8 at this time, and the reaction was oscillated for 1 hour under the process conditions of 50℃. After the reaction, the cotton fabric was taken out, washed three times with distilled water, and then dried at room temperature to test the whiteness. The whiteness of the blank control group fabric was 36.5 ( Figure 2 , that is, the value when the activator dosage is 0), the bursting strength value is 585.14, which retains about 95% of the grey cloth ( Figure 3). Compared with the bleaching performance of the activated system, it can be seen that in the acetylated cationic starch activated bleaching system, the whiteness of the fabric is significantly improved compared with the whiteness of the fabric in the blank control group. These results show that the acetylated cationic starch activator significantly improves the whiteness of the fabric and can also better retain the strength of the fabric, and has the application prospect of developing a new low-temperature and low-alkali hydrogen peroxide ecological bleaching process for cotton fabrics.

Claims

1. A hydrogen peroxide activator, It is characterized in that The hydrogen peroxide activator includes an acetylated cationic starch activator.

2. A fabric bleaching agent, It is characterized in that In terms of weight, the fabric bleaching agent comprises 5-30 parts of acetylated cationic starch activator and 4-8 parts of hydrogen peroxide.

3. The fabric bleaching agent according to claim 2, It is characterized in that The fabric bleaching agent also contains sodium bicarbonate, a refining agent, a penetrant and a stabilizer; The fabric bleaching agent comprises, by weight: 5-30 parts of acetylated cationic starch activator, 4-8 parts of hydrogen peroxide, 3-10 parts of sodium bicarbonate, 1-3 parts of refining agent, 1-3 parts of penetrant, and 0.1-1 part of stabilizer.

4. The fabric bleaching agent according to claim 2, It is characterized in that The preparation method of the acetylated cationic starch activator comprises: (1) starch, sodium hydroxide aqueous solution, and 2,3-epoxypropyltrimethylammonium chloride aqueous solution are mixed, reacted, purified, and dried to obtain cationic starch; (2) Cationic starch and acetic anhydride are mixed, and then sodium hydroxide solution is added dropwise, reacted, purified, and dried to obtain an acetylated cationic starch activator.

5. The fabric bleaching agent according to claim 4, It is characterized in that In the step (1), the ratio of starch, 2,3-epoxypropyltrimethylammonium chloride, sodium hydroxide and water is 5-10g:5-12g:5-10g:15-50mL; and the concentration of the sodium hydroxide aqueous solution is 0.1-0.5mol / L.

6. The fabric bleaching agent according to claim 4, It is characterized in that In step (1), the reaction temperature is 50-80°C and the reaction time is 1-5h; The purification includes adjusting the solution pH to 6-7 with acetic acid after the reaction is completed, and precipitating the cationic starch solid with ethanol; and the drying includes drying and then freeze-drying.

7. The fabric bleaching agent according to claim 4, It is characterized in that In the step (2), the ratio of cationic starch, acetic anhydride and sodium hydroxide solution is 10-50 g: 40-100 mL: 1-6 mL; the concentration of the sodium hydroxide solution is 10-15 mol / L.

8. The fabric bleaching agent according to claim 4, It is characterized in that In step (2), the reaction temperature is 50-70°C and the reaction time is 12-24h; The purification comprises the following steps: after the reaction liquid is cooled to room temperature, pouring it into a mixed solution of ethanol and petroleum ether and letting it stand, filtering to obtain a yellow solid, wherein the volume ratio of ethanol to petroleum ether is 1-1.5:2; and the drying comprises the following steps: drying at 45-65° C. for 24-48 hours.

9. A method for bleaching fabrics, include: The bleaching agent according to any one of claims 2 to 8 and water are mixed to obtain a bleaching solution, and then the fabric is bleached in the bleaching solution.

10. The method according to claim 9, It is characterized in that The bleaching temperature is 40-60°C, and the time is 1-2 hours; the ratio of the fabric to the bleaching solution is 1g:10-30mL; the fabric is cotton fabric; and the pH of the bleaching solution is 7.5-8.5.

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