阅读说明：本技术 一种抗低温荧光增白浆液的制备方法 (Preparation method of low-temperature-resistant fluorescent whitening slurry ) 是由 罗建 宁静 赵超越 周开丰 宁星星 于 2021-08-20 设计创作，主要内容包括：该发明涉及荧光增白剂技术领域,具体关于一种抗低温荧光增白浆液的制备方法；该发明的一种抗低温荧光增白浆液的制备方法具备白度高,荧光强,用量少,能使染品质量提高,成该降低等特点,是比较理想的涤纶荧光增白剂,该品种属低温型。可用于涤纶及涤棉、涤丝、涤麻、涤毛等各类混纺织物的增白增艳。(The invention relates to the technical field of fluorescent whitening agents, in particular to a preparation method of low-temperature-resistant fluorescent whitening slurry; the preparation method of the low-temperature-resistant fluorescent whitening slurry has the characteristics of high whiteness, high fluorescence intensity, small using amount, capability of improving the quality of dyeing, reduction of the quality and the like, is an ideal terylene fluorescent whitening agent, and belongs to a low-temperature type. Can be used for whitening and brightening various blended fabrics of terylene, polyester cotton, polyester silk, polyester hemp, polyester wool and the like.)

1. A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 5-20 parts of fluorescent whitening agent, 5-30 parts of antifreezing agent ethylene glycol, 0.2-0.3 part of preservative, 1.5-3.4 parts of dispersing synergist, 0.7-2.8 parts of high-molecular stabilizer and 50-80 parts of deionized water into a reaction kettle in parts by mass, and stirring for 0.5-2.5 hours at 20-40 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

2. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 1, characterized in that: the fluorescent whitening agent is one of 1,4-bis (2-cyanostyryl) benzene or 1-o-cyanostyryl-4-p-cyanostyryl benzene.

3. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 1, characterized in that: the preservative is sodium benzoate.

4. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 1, characterized in that: the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 12-22 parts by mass of 4-styrene sodium sulfonate 5-10 parts by mass of 3-mercapto-1, 2-propylene glycol, 0.1-1.3 parts by mass of tetra (3-mercaptoacrylic acid), 100 parts by mass of solvent and 3-6 parts by mass of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 50-57 ℃ under the stirring condition, preserving the temperature for 3-10 hours, and distilling to remove methanol to obtain the dispersion synergist.

5. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 4, characterized in that: the polymer stabilizer is selected from one of phenyl boric acid, butyl boric acid and p-bromophenyl boric acid.

6. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 4, characterized in that: the alkaline ionic liquid is selected from [ Bmim ] OH.

7. The method for preparing a dispersion synergist according to claim 4, characterized in that: the solvent is selected from: methanol, ethanol, 3-propanediol, 2, 2-diethyl-1, 3-propanediol; 2- (1-methylpropyl) -1, 3-propanediol; 2- (2-methylpropyl) -1, 3-propanediol; 2-methyl-2-propyl-1, 3-propanediol; 2, 3, 3-trimethyl-1, 2-butanediol; 2-ethyl-2-methyl-1, 4-butanediol; 2-ethyl-3-methyl-1, 4-butanediol; 2-propyl-1, 4-butanediol; 2-isopropyl-1, 4-butanediol; 2, 2, -dimethyl-1, 5-pentanediol; 2, 3, -dimethyl-1, 5-pentanediol; 2, 4-dimethyl-1, 5-pentanediol; 3, 3, -dimethyl-1, 5-pentanediol; 2, 3-dimethyl-2, 3-pentanediol; 2, 4-dimethyl-2, 3-pentanediol; 3, 4-dimethyl-2, 3-pentanediol; 4, 4-dimethyl-2, 3-pentanediol; 2, 3-dimethyl-3, 4-pentanediol; 2-ethyl-1, 5-pentanediol; 2-methyl-1, 6-hexanediol; 3-methyl-1, 6-hexanediol; 2-methyl-2, 3-hexanediol; 3-methyl-2, 3-hexanediol; 4-methyl-2, 3-hexanediol; 2, 3-hexanediol, 5-methyl-; 2-methyl-3, 4-hexanediol; 3-methyl-3, 4-hexanediol; 1, 3-heptanediol; 1, 4-heptanediol; 1, 5-heptanediol; 1, 6-heptanediol; and mixtures thereof.

8. The method for preparing a low temperature resistant fluorescent whitening slurry according to claim 4, characterized in that: the solvent is selected from: methanol, ethanol, 3-propanediol, 2, 2-diethyl-1, 3-propanediol.

Technical Field

The invention relates to the technical field of fluorescent whitening agents, in particular to a preparation method of low-temperature-resistant fluorescent whitening slurry.

Background

4-Bis (2-cyanostyryl) benzene, the English name is 1,4-Bis (2-cyanostyryl) benzene, also called fluorescent brightener ER-I, CAS registration number is 13001-39-3, the molecular formula is C24H16N2, the molecular weight is 332.3972, widely applied to textile industry, papermaking industry, synthetic detergents and other industries, wherein, 1,4-Bis (o-cyanostyryl) benzene is a representative one, has nonionic property, can be dissolved in most organic solvents, has stable chemical properties, has good high temperature resistance and light stability, has the characteristics of brightening, less dosage and high whiteness improvement, the brightening efficiency is about 10 times of the traditional fluorescent brightener DT for terylene, and is very suitable for whitening terylene (polyester) fibers.

CN201010561107.5 discloses a preparation method of a disulfonic acid liquid fluorescent whitening agent with low temperature stability, which overcomes the defects of the existing powder and liquid disulfonic acid fluorescent whitening agent products, and provides a preparation method of a disulfonic acid liquid fluorescent whitening agent with low temperature stability. The method comprises the following steps: adding disulfonic acid fluorescent whitening agent dye accounting for 10-40% of the total mass, cellosolve accounting for 10-20%, polyethylene glycol compound accounting for 2-30%, polyol compound accounting for 6-20%, urea accounting for 15-30% of the total mass and water accounting for 10-50% of the total mass into a reaction kettle, uniformly stirring, heating to 50-70 ℃, cooling to 40-45 ℃ after the materials are fully dissolved, clear and transparent, and filtering to obtain the fluorescent whitening agent. The method is simple to operate and easy to control automatically, and the disulfonic acid liquid fluorescent whitening agent produced by the method has the advantages of good water solubility, high whiteness, transparent appearance, good low-temperature stability, long-term storage, convenient use, no toxicity and no corrosion in the transportation process. However, this method uses a propionamidoethanolamine which is not easily obtained industrially as a raw material to condense and form a disulfonic acid compound, and the solution is solidified at a temperature of 0 ℃ or lower, which affects the use thereof.

CN200510012469.8 discloses liquid fluorescent whitening agent compositions. A liquid fluorescent whitening agent composition is provided. Which comprises the following steps: (a) 10-30% of a fluorescent whitening agent dye; the fluorescent whitening agent dye is a sulfostyryl biphenyl (CBS) compound, and the structure of the fluorescent whitening agent dye is shown in the formula (I): m represents hydrogen, alkali metal, magnesium or ammonium salt, and the substitution position of the sulfonic acid group can be ortho-position, meta-position or para-position of the vinyl group); (b) 20-40% of fatty alcohol-polyoxyethylene ether; (c) 10-30% polyethylene glycol; (d) 10-30% diethylene glycol; (f) 5-40% water; (g) 0.1-5% of sodium benzoate. The composition is used for whitening detergents and high-grade paper and has good stability in a wide temperature range. However, the patent does not describe the stability at low temperatures (. ltoreq.0 ℃) and the use and storage thereof are subject to certain limitations.

CN201410467058.7 discloses a stilbene triazine fluorescent whitening agent and a preparation method thereof. In particular to a stilbene bistriazine fluorescent whitening agent special for detergents and a preparation method thereof. The invention mainly solves the problems of poor whitening effect and high cost of the existing fluorescent whitening agent. The technical scheme of the invention is as follows: a stilbene triazine fluorescent whitening agent is prepared by the following method: (1) weighing the raw materials; (2) preparing a product IV; (4) uniformly mixing aniline and m-chloroaniline, and adding the mixture into the product IV obtained in the step (3) to obtain products V, VI and VII; (5) preparing compositions I, II and III; (6) acid precipitation; (7) drying; (8) to prepare the stilbene triazine fluorescent whitening agent. However, the patent does not teach the use and storage of the optical brightener at low temperatures.

The fluorescent whitening agent used in the above invention and the prior patent has the disadvantage that it cannot be stably used at low temperature (less than or equal to 0 ℃) and stored and transported, and has certain limitation.

Disclosure of Invention

The invention provides a preparation method of low-temperature resistant fluorescent whitening slurry, aiming at the defects that the existing fluorescent whitening agent and the composition thereof in the market at present have poor stability under the condition of low temperature (less than or equal to 0 ℃) and are difficult to meet the requirements of normal use, storage and transportation.

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 5-20 parts by mass of a fluorescent whitening agent, 5-30 parts by mass of an antifreezing agent glycol, 0.2-0.3 part by mass of a preservative, 1.5-3.4 parts by mass of a dispersion synergist, 0.7-2.8 parts by mass of a high-molecular stabilizer and 50-80 parts by mass of deionized water into a reaction kettle, and stirring at 20-40 ℃ for 0.5-2.5 hours to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is one of 1,4-bis (2-cyanostyryl) benzene or 1-o-cyanostyryl-4-p-cyanostyryl benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 12-22 parts of 4-styrene sodium sulfonate, 5-10 parts of 3-mercapto-1, 2-propylene glycol, 0.1-1.3 parts of tetra (3-mercaptoacrylic acid), 100 parts of solvent and 3-6 parts of alkaline ionic liquid into a reaction kettle according to parts by weight, introducing nitrogen, controlling the temperature to be 50-57 ℃ under the stirring condition, preserving the temperature for 3-10 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is selected from one of phenyl boric acid, butyl boric acid and p-bromophenyl boric acid.

Further, the basic ionic liquid is selected from 1-butyl-3-methylimidazole hydroxide, and the chemical formula is [ Bmim ] OH. CAS number: 528818-81-7.

Further, the solvent is selected from: methanol, ethanol, 3-propanediol, 2, 2-diethyl-1, 3-propanediol; 2- (1-methylpropyl) -1, 3-propanediol; 2- (2-methylpropyl) -1, 3-propanediol; 2-methyl-2-propyl-1, 3-propanediol; 2, 3, 3-trimethyl-1, 2-butanediol; 2-ethyl-2-methyl-1, 4-butanediol; 2-ethyl-3-methyl-1, 4-butanediol; 2-propyl-1, 4-butanediol; 2-isopropyl-1, 4-butanediol; 2, 2, -dimethyl-1, 5-pentanediol; 2, 3, -dimethyl-1, 5-pentanediol; 2, 4-dimethyl-1, 5-pentanediol; 3, 3, -dimethyl-1, 5-pentanediol; 2, 3-dimethyl-2, 3-pentanediol; 2, 4-dimethyl-2, 3-pentanediol; 3, 4-dimethyl-2, 3-pentanediol; 4, 4-dimethyl-2, 3-pentanediol; 2, 3-dimethyl-3, 4-pentanediol; 2-ethyl-1, 5-pentanediol; 2-methyl-1, 6-hexanediol; 3-methyl-1, 6-hexanediol; 2-methyl-2, 3-hexanediol; 3-methyl-2, 3-hexanediol; 4-methyl-2, 3-hexanediol; 2, 3-hexanediol, 5-methyl-; 2-methyl-3, 4-hexanediol; 3-methyl-3, 4-hexanediol; 1, 3-heptanediol; 1, 4-heptanediol; 1, 5-heptanediol; 1, 6-heptanediol; and mixtures thereof.

Further, the solvent is selected from: methanol, ethanol, 3-propylene glycol and 1, 4-heptanediol.

The reaction mechanism is as follows:

the dispersant prepared by the invention adopts 4-styrene sodium sulfonate, 3-mercapto-1, 2-propanediol and tetra (3-mercaptoacrylic acid) to respectively carry out Michael addition reaction, the introduction of the propanediol has the performance of improving low temperature, and can have high compatibility with the fluorescent whitening agent, and the branched chain of the dispersant enables the fluorescent whitening agent particles to be well dispersed in aqueous solution.

The technical effects are as follows:

the low-temperature-resistant fluorescent whitening slurry prepared by the invention has the following effects:

(1) the slurry has low freezing point and low temperature resistance, and can be stored at the temperature of minus 10 ℃ without freezing.

(2) The dispersibility is obviously improved compared with the common brightening agent.

(3 the low temperature stability is good (-10 ℃) and the storage time is long, and the use is convenient.

Drawings

FIG. 1 is a Fourier infrared spectrum of the dispersion synergist prepared in example 2:

the existence of a carbon-hydrogen bond stretching absorption peak near 3042/2938/2867cm < -1 >, a benzene ring skeleton stretching absorption peak near 1607/1502/1451cm < -1 >, a sulfonate ion stretching absorption peak near 1116cm < -1 >, and a sulfur-oxygen double bond absorption peak near 1032cm < -1 >, which indicates that the 4-sodium styrene sulfonate participates in the reaction; a stretching absorption peak of a carbon-sulfur bond exists near 762cm < -1 >, and a stretching absorption peak of a hydroxyl exists near 3370cm < -1 >, so that the 3-mercapto-1, 2-propanediol participates in the reaction; a telescopic absorption peak of the carboxyl carbonyl exists near 1807cm < -1 >, which indicates that the tetra (3-mercaptoacrylic acid) participates in the reaction; the absorption peak of the thiol group at about 2553cm-1 was almost disappeared, indicating that the thiol group was sufficiently reacted with the carbon-carbon double bond.

Detailed Description

The invention is further illustrated by the following specific examples:

the detection method for the low-temperature resistance of the fluorescent brightener slurry comprises the following steps:

1 reagent and sample

A sample of a fluorescent brightener slurry;

2 instrumentation

2.1 thermometer (-30 ℃ -50 ℃);

2.2, refrigerating cabinets;

2.3BT-9300ST laser particle size distribution instrument.

2.4HH-2 constant temperature water bath

3 detection step

3.1 detection of fluidity of the slurry after cryogenic storage

100ml of plastic bottle is filled with about 80g of whitening agent slurry, the bottle cap is screwed down, and the mixture is stored for 24 hours at low temperature (0 ℃ to minus 10 ℃).

The cryogenically refrigerated slurry was taken out, the bottle was shaken, and the fluidity of the slurry in the bottle was observed with the naked eye.

3.2 appearance and particle size detection of thawed slurry

And (4) after the fluidity of the low-temperature refrigerated slurry is detected, putting the slurry into a constant-temperature water bath kettle at 25 ℃ for unfreezing for 30 min.

Taking out the slurry, and observing whether the slurry in the bottle has solid-liquid separation and precipitation by naked eyes; the bottle was shaken and the particle size of the slurry was measured using a laser particle size distribution instrument.

Example 1

Adding 5g of fluorescent whitening agent, 5g of antifreeze ethylene glycol, 0.2g of preservative, 1.5g of dispersion synergist, 0.7g of polymer stabilizer and 80g of deionized water into a 250ml beaker, and stirring for 2 hours at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1,4-bis (2-cyanostyryl) benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 12g of 4-styrene sodium sulfonate, 5g of 3-mercapto-1, 2-propylene glycol, 0.1g of tetra (3-mercaptoacrylic acid), 100g of solvent and 3g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is phenylboronic acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is methanol.

Example 2

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 10g of fluorescent whitening agent, 10g of antifreeze ethylene glycol, 0.25g of preservative, 2g of dispersion synergist, 1.2g of polymer stabilizer and 80g of deionized water into a 250ml beaker, and stirring for 2h at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1-o-cyanostyryl-4-p-cyanostyryl benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 16g of 4-styrene sodium sulfonate, 8g of 3-mercapto-1, 2-propylene glycol, 0.5g of tetra (3-mercaptoacrylic acid), 110g of solvent and 4g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is butyl boric acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is ethanol.

Example 3

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 15g of fluorescent whitening agent, 20g of antifreeze ethylene glycol, 0.28g of preservative, 2.5g of dispersion synergist, 2.0g of polymer stabilizer and 60g of deionized water into a 250ml beaker, and stirring for 2 hours at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1,4-bis (2-cyanostyryl) benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 20g of 4-styrene sodium sulfonate, 8g of 3-mercapto-1, 2-propylene glycol, 1.0g of tetra (3-mercaptoacrylic acid), 120g of solvent and 5g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 50 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is p-bromophenyl boric acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is 3-propylene glycol.

Example 4

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 20g of fluorescent whitening agent, 30g of antifreeze ethylene glycol, 0.3g of preservative, 3.4g of dispersion synergist, 2.8g of polymer stabilizer and 50g of deionized water into a 250ml beaker, and stirring for 2h at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1-o-cyanostyryl-4-p-cyanostyryl benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 22g of 4-styrene sodium sulfonate, 10g of 3-mercapto-1, 2-propylene glycol, 1.3g of tetra (3-mercaptoacrylic acid), 120g of solvent and 6g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is benzene selected from [ Bmim ] OH.

Further, the solvent is 1, 4-heptanediol.

Comparative example 1

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 5g of fluorescent whitening agent, 0.2g of preservative, 1.5g of dispersion synergist, 0.7g of polymer stabilizer and 50g of deionized water into a 250ml beaker, and stirring for 2 hours at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1,4-bis (2-cyanostyryl) benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 12g of 4-styrene sodium sulfonate, 5g of 3-mercapto-1, 2-propylene glycol, 0.1g of tetra (3-mercaptoacrylic acid), 100g of solvent and 3g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is phenylboronic acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is methanol.

Comparative example 2

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 15g of fluorescent whitening agent, 1g of antifreeze ethylene glycol, 0.3g of preservative, 2.5g of dispersion synergist, 1.8g of polymer stabilizer and 70g of deionized water into a 250ml beaker, and stirring for 2 hours at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1-o-cyanostyryl-4-p-cyanostyryl benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 18g of 4-styrene sodium sulfonate, 8g of 3-mercapto-1, 2-propylene glycol, 0.8g of tetra (3-mercaptoacrylic acid), 110g of solvent and 5g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is butyl boric acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is ethanol.

Comparative example 3

A preparation method of low-temperature-resistant fluorescent whitening slurry comprises the following operation steps:

adding 20g of fluorescent whitening agent, 20g of solvent ethanol, 0.3g of preservative, 2.5g of dispersion synergist, 2.8g of polymer stabilizer and 80g of deionized water into a 250ml beaker, and stirring for 2 hours at 30 ℃ to obtain the low-temperature resistant fluorescent whitening slurry.

Further, the fluorescent whitening agent is 1,4-bis (2-cyanostyryl) benzene.

Further, the preservative is sodium benzoate.

Further, the dispersion synergist is prepared by the following method, and comprises the following steps:

adding 22g of 4-styrene sodium sulfonate, 10g of 3-mercapto-1, 2-propylene glycol, 1.3g of tetra (3-mercaptoacrylic acid), 120g of solvent and 6g of alkaline ionic liquid into a reaction kettle, introducing nitrogen, controlling the temperature to be 55 ℃ under the stirring condition, preserving the temperature for 8 hours, and distilling to remove methanol to obtain the dispersion synergist.

Further, the polymer stabilizer is one of p-bromophenyl boric acid.

Further, the alkaline ionic liquid is [ Bmim ] OH.

Further, the solvent is 3-propylene glycol.

TABLE 1 results of slurry fluidity test after low temperature refrigeration

Performance index	Low temperature refrigeration at 0 deg.C	-10℃Low temperature refrigeration	Low temperature resistance
				Example 1	Good fluidity	Good fluidity	Resisting-10 deg.C
Example 2	Good fluidity	Good fluidity	Resisting-10 deg.C
				Example 3	Good fluidity	Good fluidity	Resisting-10 deg.C
Example 4	Good fluidity	Good fluidity	Resisting-10 deg.C
				Comparative example 1	No flow	No flow	Intolerance of low temperature
Comparative example 2	No flow	No flow	Intolerance of low temperature
				Comparative example 3	No flow	No flow	Intolerance of low temperature

TABLE 2 results of the appearance and particle size measurements of the slurry thawed at low temperature

As can be seen from table 1, the preparation method of adding the low temperature resistant fluorescent whitening slurry in preferred embodiments 1 to 4 of the application can significantly improve the use and storage of the fluorescent whitening agent at low temperature, and can also improve the whiteness of the dyed and printed product. Good color development at low temperature, can improve the quality of the dye and reduce the cost.