Low temperature fabric bleaching agent

Abstract

The present application relates to a low-temperature fabric bleaching agent, which comprises an acetylated cationic starch activator. In the present application, the raw material of the activator is natural starch which is green and environmentally friendly, the preparation method is simple, the yield is high, and the activator can be produced on a large scale. The cationic starch activator has good bleaching promotion performance on cotton fabric and is suitable for industrialization and popularization, and has important application prospects in the development of a new process of low-temperature hydrogen peroxide bleaching of cotton fabric.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fabric bleaching, and particularly relates to a fabric bleaching agent. BACKGROUND

[0002] Cotton fibers usually need to be pretreated and bleached to remove natural impurities such as pigments to meet the requirements of textile processing. Bleaching with hydrogen peroxide is a widely used process. The traditional hydrogen peroxide bleaching process is a high-energy consumption process at high temperature (98℃) and strong alkali (pH>12 NaOH). In the context of the current national "double carbon target", it is urgent to develop an ecological bleaching process at low temperature and weak alkali to meet the urgent needs of energy saving and emission reduction in the textile industry. Activating hydrogen peroxide with an activator is an important way to develop a low-temperature and weak-alkali bleaching process for cotton fabrics, but there are still problems such as high bleaching temperature (>70℃), strong alkalinity (pH>10), poor water solubility of the activator, and poor biodegradability. SUMMARY

[0003] In view of the defects of the prior art, the technical problem to be solved by the present application is to provide a low-temperature fabric bleaching agent. The present application uses natural starch as a green raw material and designs and synthesizes a cationic starch activator with excellent water solubility, which can activate hydrogen peroxide at low temperature (50℃) and low alkali (pH=8 NaHCO3) process conditions to pretreat cotton fabrics, achieving good bleaching effect and having application prospect for industrialization.

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

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

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

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

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

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

[0010] (1) mixing starch, sodium hydroxide aqueous solution, 2,3-epoxypropyl trimethyl ammonium chloride aqueous solution, reacting, purifying, drying to obtain cationic starch;

[0011] (2) mixing cationic starch and acetic anhydride, then adding sodium hydroxide solution dropwise, reacting, purifying, drying to obtain acetylated cationic starch activator.

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

[0013] Preferably, the reaction temperature in step (1) is 50-80℃, and the reaction time is 1-5 h; the purifying is adjusting the pH of the solution to 6-7 with acetic acid and precipitating the cationic starch solid with ethanol; and the drying is drying for 10-12 h and then freeze-drying for 24-48 h.

[0014] Purifying in step (1): cooling the reaction solution to room temperature, adjusting the pH to 6-7 with acetic acid, and precipitating the light yellow solid after adding ethanol.

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

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

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

[0018] The application provides a fabric bleaching method, which comprises: mixing any of the bleaching agents and water to obtain a bleaching solution, and then bleaching the fabric in the bleaching solution, washing and drying.

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

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

[0021] The bleaching is oscillated for 1-2 h at a temperature of 40-60 ℃ on a dyeing machine.

[0022] The application provides a preparation method of a hydrogen peroxide activator by using green natural starch as a raw material.

[0023] The cationic starch activator is prepared by the reaction of starch and 2,3-epoxypropyl trimethyl ammonium chloride, and then reacted with acetic anhydride. The activator can activate hydrogen peroxide at a low temperature of 50 ℃ to significantly improve the whiteness of cotton fabric. In the application, the raw material of the activator is green and environmentally friendly natural starch, the preparation method is simple, the yield is high, and the cationic starch activator can be produced on a large scale. The cationic starch activator has good promotion performance on cotton fabric and is suitable for industrialization and promotion. The application has important application prospects in the development of a new hydrogen peroxide low-temperature bleaching process for cotton fabric.

[0024] Advantageous effects

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

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

[0027] Figure 2 The relationship between the amount of cationic starch activator and the whiteness of fabric in Example 3;

[0028] Figure 3 The change diagram of fabric bursting strength before and after bleaching in Example 3. DETAILED DESCRIPTION

[0029] The application will be further described in connection with specific embodiments. It should be understood, however, that the application is not limited in scope to the particular embodiments disclosed. Furthermore, variations on described embodiments, which become apparent to those of ordinary skill in the art once given the benefit of this disclosure, are embraced by the scope of the application as it is defined by the claims at the end of this report. Embodiments of the application will be described in conjunction with the following drawings in which like reference numerals refer to like elements throughout:

[0030] Relevant tests:

[0031] Infrared spectrum was tested on PE company Spectrum Two instrument in the United States.

[0032] The colorimeter used for whiteness determination is Datacolor SF1000, and the whiteness of the fabric is tested according to the standard ASTM E313-20. The strength of the fabric is tested by using an electronic fabric strength machine - bursting (model YG026Q) according to the national standard GB / T 19976-2005.

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

[0034] Example 1

[0035] Synthesis of cationic starch and acetylated cationic starch activator:

[0036] The starch (10 g) was dispersed in 25 mL of sodium hydroxide solution (0.125 mol / L), heated in an oil bath to 60°C, and 10 mL of 2,3-epoxypropyltrimethylammonium chloride aqueous solution (1.2 g / mL) was added under magnetic stirring, and the reaction was continued for 4 hours. After cooling to room temperature, the solution was adjusted to pH = 6-7 with acetic acid, 70 mL of ethanol was added, and the precipitated solid was filtered and dried at 60°C for 12 hours, and then freeze-dried for 48 hours, to obtain 14 g of cationic starch with a yield of 72%. The infrared spectrum of the cationic starch product is shown in Figure 1 Compared with the starch raw material, the characteristic stretching vibration peak of C-H in the cationic- -1 N(CH3)3 appeared at 1478 cm + , indicating that the cationic starch had been successfully prepared.

[0037] The cationic starch (10 g) was mixed with acetic anhydride (40 mL) in a flask, 1.25 mL of sodium hydroxide solution (12.5 mol / L) was added dropwise under magnetic stirring, and the oil bath was heated to 60°C for 24 hours. After cooling to room temperature, it was poured into 90 mL of ethanol-petroleum ether (volume ratio 1:2) and left 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 Figure 1As shown. Compared to starch, acetylated cationic starch at 1735 cm⁻¹ -1 A strong characteristic absorption peak of the C=O carbonyl group appears at 1224 cm⁻¹. -1 A CO absorption peak appears in the carboxylic acid ester bond, located at 2979 cm⁻¹. -1 2903cm -1 and 1372cm -1 The alkyl peak at 3300 cm⁻¹ was also significantly enhanced, and a peak at 3300 cm⁻¹ was also observed. -1 The near-complete disappearance of the hydroxyl peak in the starch raw material indicates that acetylated cationic starch has been successfully prepared.

[0038] Example 2

[0039] Application of acetylated cationic starch activator in activating hydrogen peroxide-bleached cotton fabrics.

[0040] 5g of cotton fabric was immersed in 100ml of bleaching bath solution, which contained the acetylated cationic starch activator synthesized in Example 1 (5-30g / L), 30% hydrogen peroxide (5g / L), sodium bicarbonate (4g / L), refining agent (1g / L), penetrant (1g / L), and stabilizer (0.5g / L). The pH of the bleaching bath solution was measured to be 8. The reaction was carried out at 50℃ with shaking for 1 hour. After the reaction, the cotton fabric was removed, washed three times with distilled water, and then air-dried at room temperature. The whiteness was then tested. It can be seen that the whiteness of the fabric increases with the addition of acetylated cationic starch. In the presence of 30g / L acetylated cationic starch activator, the whiteness can reach 61.5 (e.g., ...). Figure 2 (As shown). 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 30 g / L acetylated starch activator is 593.21, retaining more than 96% of the strength of the greige fabric (e.g., ...). Figure 3 (As shown).

[0041] Example 3

[0042] The blank control group was cotton fabric bleached with hydrogen peroxide.

[0043] 5g of cotton fabric was immersed in 100ml of bleaching bath solution containing 30% hydrogen peroxide (5g / L), sodium bicarbonate (4g / L), refining agent (1g / L), penetrant (1g / L), and stabilizer (0.5g / L). The pH of the bleaching bath solution was 8 at this point. The reaction was carried out at 50℃ with shaking for 1 hour. After the reaction, the cotton fabric was removed, washed three times with distilled water, and then air-dried at room temperature. The whiteness was then tested. The whiteness of the blank control group fabric was 36.5 (…). Figure 2 (This refers to the value when the activator dosage is 0), the bursting strength value is 585.14, retaining approximately 95% of the greige fabric ( Figure 3). Compared with the bleaching performance of the activation system, the whiteness of the fabric in the acetylated cationic starch activation bleaching system was significantly improved compared with the blank control group. These results showed that acetylated cationic starch activator significantly improved the whiteness of the fabric, while also well preserved the strength of the fabric, with the application prospect of developing new process of cotton fabric low-temperature low-alkali hydrogen peroxide ecological bleaching.

Claims

1. A hydrogen peroxide activator, characterized in that, The hydrogen peroxide activator includes an acetylated cationic starch activator; The method for preparing the acetylated cationic starch activator includes: (1) Mix starch, sodium hydroxide aqueous solution and 2,3-epoxypropyltrimethylammonium chloride aqueous solution, react, purify and dry to obtain cationic starch; (2) Mix cationic starch and acetic anhydride, then add sodium hydroxide solution dropwise, react, purify, and dry to obtain acetylated cationic starch activator.

2. A fabric bleaching agent, characterized in that, By weight, the fabric bleaching agent comprises 5-30 parts of acetylated cationic starch activator and 4-8 parts of hydrogen peroxide; The method for preparing the acetylated cationic starch activator includes: (1) Mix starch, sodium hydroxide aqueous solution and 2,3-epoxypropyltrimethylammonium chloride aqueous solution, react, purify and dry to obtain cationic starch; (2) Mix cationic starch and acetic anhydride, then add sodium hydroxide solution dropwise, react, purify, and dry to obtain acetylated cationic starch activator.

3. The fabric bleaching agent according to claim 2, characterized in that, The fabric bleaching agent also contains sodium bicarbonate, refining agent, penetrant and 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 parts of stabilizer.

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

5. The fabric bleaching agent according to claim 2, characterized in that, The reaction temperature in step (1) is 50-80℃ and the reaction time is 1-5h; The purification process involves adjusting the pH of the solution to 6-7 with acetic acid after the reaction, and then precipitating cationic starch solids with ethanol; the drying process involves drying followed by freeze drying.

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

7. The fabric bleaching agent according to claim 2, characterized in that, The reaction temperature in step (2) is 50-70℃ and the reaction time is 12-24h; The purification process involves cooling the reaction solution to room temperature, pouring it into a mixed solution of ethanol and petroleum ether, allowing it to stand, and filtering to obtain a yellow solid, wherein the volume ratio of ethanol to petroleum ether is 1-1.5:2; the drying process involves drying at 45-65℃ for 24-48 hours.

8. A method for bleaching fabrics, comprising: The bleaching agent described in any one of claims 2-7 is mixed with water to obtain a bleaching solution, and then the fabric is bleached in the bleaching solution.

9. The method according to claim 8, characterized in that, The bleaching temperature is 40-60℃, and the time is 1-2 hours; the ratio of the fabric to the bleaching solution is 1g:10-30mL; the fabric is cotton; and the pH of the bleaching solution is 7.5-8.5.

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