TWI717058B - Preparation method and finished product of fluorescent whitening agent hexasulfonic acid - Google Patents

Abstract

A preparation method of fluorescent whitening agent hexasulfonic acid, comprising the following mass ratio of raw materials: 15-25% aniline 2,5 disulfonic acid monosodium salt, 10-15% 4,4'-diaminodiphenyl Ethylene-2,2'-disulfonic acid, 10-15% cyanuric chloride, 10-15% sodium glutamate and diisopropanolamine mixture, 30-50% alkaline elements; the preparation method includes The following steps: (a) Add cyanuric chloride to water, stir to dissolve it to obtain a cyanuric chloride solution, then add aniline 2,5 disulfonic acid monosodium salt solution, and then add alkaline elements to adjust the pH to 6-8. Get one-step condensation product; (b) Add 4,4'-diaminostilbene-2,2'-disulfonic acid solution to the one-step condensation product, and then add alkaline elements to adjust the pH to 6-8 to obtain a two-step condensation product ;as well as (c) Add a mixture of sodium glutamate and diisopropanolamine to the two-step condensation product, and then adjust the pH to 8-10 with a basic element to obtain a finished product of hexasulfonic acid. The whitening effect of the hexasulfonic acid prepared by the above preparation method can be 5% higher than that of the traditional hexasulfonic acid.

Description

Preparation method of fluorescent whitening agent hexasulfonic acid and its finished products

The present invention relates to a preparation method of fluorescent whitening agent hexasulfonic acid and its finished products.

With the development of science and technology, people have higher and higher requirements for the quality of printed matter, and the demand for printed matter with clear images, bright colors and high image reproducibility is increasing. As the main printing carrier, the whiteness and hue of paper will greatly affect the quality of printed matter; various printing plants continue to improve the quality of their products and raise the requirements for paper whiteness, but the existing hexasulfonic acid is in the fluorescent whiteness The above can no longer meet the needs of customers for producing high-end products. In order to achieve this goal, new brighteners must be developed to meet the needs.

The history of fluorescent whitening agents can be traced back to 1929. German scientist Paul Krais used natural compounds for fluorescent whitening experiments; in 1930, the first synthetic coumarin structure of fluorescent whitening agents was synthesized; in 1934, British ICI synthesis The 4,4,-diaminostilbene-2,2,-disulfonic acid bis-acetoxy derivative, which has obvious whitening effect on paper, revealed the beginning of the synthetic field of fluorescent whitening agent; 1940, Germany B. Wendt et al. discovered DSD acid bistriazine derivatives, which laid the foundation for large-scale production; in 1941, Bayer launched a stilbene type fluorescent whitening agent under the brand name Blankophor B, which achieved fluorescence enhancement. The commercial industrial production of whitening agents. After World War II, dye companies in Switzerland, the United Kingdom, the United States and Japan joined the research and production of fluorescent whitening agents. The research and development of fluorescent whitening agents have developed rapidly. Compounds with different parent structures of styrene emerged in large numbers; in 1945, Ciba Company developed a bisbenzoxazole derivative It is used for whitening plastics and synthetic fibers; in 1949, Ilford invented a fluorescent whitening agent based on pyrazoline; in 1957, Geigy Company developed a pyrazine derivative fluorescent whitening agent according to the chemical structure type. It is divided into 15 basic structures, nearly 400 compounds, and 3000 brand names. There are about ten chemical structure types and nearly one hundred compounds with high commercial value. Brighteners have been widely used in textiles, papermaking, washing powder, soap, rubber, plastics, pigments and paints. Fluorescent brighteners of different chemical structure types have different properties, and different objects and conditions of use. Some types of fluorescent brighteners have a wide range of applications and can be used in several different industries.

Due to the lignin remaining in the paper fiber, it slightly absorbs the blue light (420-480nm) in the visible light (wavelength range of 400-800nm), resulting in insufficient blue, making it slightly yellow or off-white, and the whiteness is affected And give people a sense of old and unclean. Therefore, different measures have been taken to whiten and brighten items. There are two methods commonly used, one is Garland whitening. That is, add a small amount of blue pigment (such as ultramarine) to the pre-whitened article, and cover the yellowish color of the matrix by increasing the reflection of the blue light part to make it appear whiter. Although Garland can whiten, it has a limited effect, and the brightness decreases due to the decrease of the total reflected light, and the color of the object becomes darker. Another method is chemical bleaching, which fades the color of the surface of the object with the pigment by redox reaction, so it will inevitably have a destructive effect on the cellulose, and the bleached object is yellow, which affects the visual perception. The fluorescent whitening agent discovered later made up for the shortcomings of the above method and showed incomparable superiority.

In the paper industry, fluorescent whitening agents can be added in the pulp, or used in surface sizing and coating materials to improve the whiteness of paper products and make them bright and pleasing. Its dosage is small and it is convenient to use. It is widely used in the production process of paper with high whiteness requirements. However, in the process of using the fluorescent whitening agent, its whitening effect will be affected by various factors to varying degrees.

For the application of brighteners in the wet end, compared with hexasulfonic acid brighteners, disulfonic acid brighteners and tetrasulfonic acid brighteners are the best ones. On the one hand, their solubility in water is low; The fiber has high direct dyeability. Because the hexasulfonic acid whitening agent has extremely high water solubility, it has poor direct dyeability to fibers, resulting in low cost performance. Therefore, the current wet end applications are mainly disulfonic acid whiteners and tetrasulfonic acid whiteners. In the surface sizing process, adhesives (starch, calcium carbonate or other colloids) are used. Some of them are cationic. The disulfonic acid varieties are more sensitive to cationic compounds, so they are not suitable for use in surface sizing solutions. Use four or six sulfonic acid based varieties, and under low concentration conditions, disulfonic acid whitening agent shows green light, not recommended. If the whiteness requirement of the finished paper is not high, then the tetrasulfonic acid whitening agent has a better cost performance; on the contrary, the hexasulfonic acid whitening agent can provide higher paper whiteness.

Chinese Patent No. CN104312197B discloses a hexasulfonic acid liquid fluorescent whitening agent and its preparation method and application. The preparation method of the hexasulfonic acid liquid fluorescent whitening agent includes the following steps: Tripolychloride at 0-15°C cyanide for 1 hour with aniline 2,5-disulfonic acid, pH controlled to 6 to 7, a condensation product of synthetic step; step condensation product with 4,4 '- diamino stilbene-2,2' - disulfonic acid 30 React at ℃~45℃ for 1 hour, and control the pH at 6.8~7.5 to synthesize the two-step condensation product; the two-step condensation product and diethanolamine are reacted at a temperature of 90-98℃ for 3.5 hours, and the pH is controlled at 8-9. The hexasulfonic acid liquid fluorescent whitening agent provided by the invention has significantly improved fluorescence intensity, good water solubility, high whiteness when applied to paper, transparent appearance, good stability at room temperature, can be stored for a long time, is convenient to use, and is transported It is non-toxic and non-corrosive.

However, for the whiteness requirements in the industry, the conventional hexasulfonic acid liquid fluorescent whitening agents are slightly insufficient to cope with it. Therefore, it is necessary to design a fluorescent whitening agent hexasulfonic acid with higher whiteness. The inventor made further research and finally revealed the preparation method of the fluorescent whitening agent hexasulfonic acid of the present invention.

The purpose of the present invention is to provide a method for preparing fluorescent whitening agent hexasulfonic acid, which includes the following mass ratio of raw materials: 15-25% aniline 2,5 disulfonic acid monosodium salt; 10-15% 4 ,4'-Diaminostilbene-2,2'-disulfonic acid; 10-15% cyanuric chloride; 10-15% sodium glutamate and diisopropanolamine mixture; and 30-50 % Of basic elements.

The preparation method of the fluorescent whitening agent hexasulfonic acid of the present invention includes: (a) adding cyanuric chloride to water, stirring to dissolve it to obtain a cyanuric chloride solution, and then adding aniline 2,5 disulfonic acid Acid monosodium salt solution, followed by adding alkaline elements to adjust the pH to 6-8 to obtain a one-step condensation product; (b) adding 4,4'-diaminostilbene-2,2' to the one-step condensation product -Disulfonic acid solution, and then add alkaline elements to adjust the pH to 6-8 to obtain a two-step condensation product; and add a mixture of sodium glutamate and diisopropanolamine to the two-step condensation product, and then use alkaline elements Adjust the pH value to 8-10 to obtain the finished product of hexasulfonic acid.

In the method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, the above-mentioned sodium glutamate mixture refers to a mixture of sodium glutamate and diisopropanolamine, and the mass ratio is 5:1 to 1:1. The alkaline element refers to alkaline particles, powders or solutions of sodium hydroxide, sodium bicarbonate, sodium carbonate, etc., and the present invention does not limit the type or form of the alkaline element.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction in step (a) is 0-15°C, and the reaction time is 0.8-1.2 hours.

In the method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, the temperature condition of the reaction in step (b) is 30-50°C, and the reaction time is 1.5-2.5 hours.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction in step (c) is 90-100° C., and the reaction time is 1.5-2.5 hours.

Compared with the conventional hexasulfonic acid, the fluorescent whitening agent hexasulfonic acid product prepared according to the preparation method of the fluorescent whitening agent hexasulfonic acid disclosed in the present invention has more hydroxyl and carboxyl groups and is alkaline, which improves the redness The phenomenon of shifting and fluorescence intensity; enhance its negative charge, lengthen its flatness, and also increase the fluorescence intensity, making its whitening effect 5% higher than traditional hexasulfonic acid; under the same whiteness, it can reduce whitening The amount of agent used; under the same amount of use, the paper can obtain higher whiteness; in addition, the addition of hydroxyl and carboxyl groups makes it more water-soluble, which makes the product more stable in water, which is conducive to higher concentration and long-term storage , Can also reduce the use of water; thus achieve the cost advantage of raw materials, reduce the amount of raw water used, and reduce the production of waste water, which has market potential and value.

The preferred examples disclosed in the present invention can be made clear from the following description and the accompanying drawings.

Figure 1 is a whiteness comparison chart of the hexasulfonic acid prepared by the present invention and the existing hexasulfonic acid. The squares in the figure represent the hexasulfonic acid prepared according to the present invention, and the oblique squares represent the conventional hexasulfonic acid.

[Example One]:

The preparation method of the fluorescent whitening agent hexasulfonic acid disclosed in the present invention includes the following mass ratio of raw materials: 15% aniline 2,5 disulfonic acid monosodium salt; 10% 4,4'-diaminodiphenyl Ethylene-2,2'-disulfonic acid; 15% cyanuric chloride; 15% sodium glutamate and diisopropanolamine mixture; and 45% alkaline elements.

In the method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, the mass ratio between sodium glutamate and diisopropanolamine is 2:1. In other embodiments, the mass ratio between sodium glutamate and diisopropanolamine is 5:1 to 1:1.

The above-mentioned alkaline element may be alkaline particle powder or solution such as sodium carbonate, sodium hydroxide or sodium bicarbonate, and the present invention does not limit the type or form of the alkaline element.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention includes the following steps: (a) Add cyanuric chloride to water, stir to dissolve to obtain a cyanuric chloride solution, and then add aniline 2,5 Disulfonic acid monosodium salt solution, followed by adding alkaline elements to adjust the pH to 6 to obtain a one-step condensation product; (b) adding 4,4'-diaminostilbene-2,2' to the one-step condensation product -Disulfonic acid solution, and then add alkaline elements to adjust the pH to 6 to obtain a two-step condensation product; and (c) add a mixture of sodium glutamate and diisopropanolamine to the two-step condensation product, and then use alkaline The element adjusts the pH value to 8, and the finished product of hexasulfonic acid is obtained.

The present invention discloses the preparation method of the fluorescent whitening agent hexasulfonic acid in this embodiment, wherein the temperature condition of the reaction in step (a) is 0° C., and the reaction time is 0.8 hours.

The present invention discloses the preparation method of the fluorescent whitening agent hexasulfonic acid in this embodiment, wherein the temperature condition of the reaction in step (b) is 30° C., and the reaction time is 1.5 hours.

The present invention discloses the preparation method of the fluorescent whitening agent hexasulfonic acid in this embodiment, wherein the temperature condition of the reaction in step (c) is 90° C., and the reaction time is 1.5 hours.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein in step (a), cyanuric chloride, aniline 2,5 disulfonic acid monosodium salt are used to react with basic elements [such as sodium hydroxide] , Cyanuric chloride contains triazine-based active groups, which can be used as a bridge for the unity of fluorescent groups; aniline 2,5 disulfonic acid monosodium salt has a benzene ring in its structure, which can absorb ultraviolet light and emit blue light , The two sulfonate groups on the benzene ring can also increase its hydrophilicity and negative charge. The amino group is a auxochrome group and a hydrophilic group, and it is a functional group synthesized with cyanuric chloride; sodium hydroxide and aniline 2,5 The monosodium disulfonic acid salt reacts to generate sodium sulfonate to increase its alkalinity, increase the affinity of coloring power and paper, and also act as a synthetic alkali agent to adjust the pH value (acid-base value).

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein (b) step is to add 4,4'-diaminostilbene-2,2'-disulfonic acid to react; 4,4'- Diaminostilbene-2,2'-disulfonic acid has long-chain conjugated bonds (benzene ring and ethylene) which can increase the amount of ultraviolet light absorption, and two sulfonate groups can also increase its hydrophilicity and negative charge. Amino is a auxochrome group and a hydrophilic group, and it is a functional group synthesized with cyanuric chloride; sodium carbonate reacts with 4,4'-diaminostilbene-2,2'-disulfonic acid to generate sulfonic acid Sodium increases its alkalinity, increases the affinity of coloring power and paper, and is also used as a synthetic alkali agent to adjust the pH value (acid-base value).

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein (c) step is to add a mixture of sodium glutamate and diisopropanolamine for synthesis; the present invention uses sodium glutamate instead of traditional hexasulfonic acid The carboxyl groups and hydroxyl groups on diethylamine, sodium glutamate and diisopropanolamine can increase the hydrophilicity and red shift, and can also increase the negative charge. The higher the negative charge, the stronger the repulsion with the sulfonate group, and the increased fluorescence The higher the flatness of the whitening agent, the more blue light reflected by the absorption of ultraviolet light, the stronger the whitening effect, and the stronger the negative charge, the higher the hydrophilicity; in addition, sodium glutamate reacts with the above-mentioned raw materials, and Na ions replace the hydroxyl and carboxyl groups. H ions increase the alkalinity of the brightener, increase the affinity of the coloring power and paper, and also act as a synthetic alkali agent, which is responsible for adjusting the pH value (acid-base value).

Compared with traditional hexasulfonic acid, the hexasulfonic acid obtained in the present invention adds multiple hydroxyl groups and carboxyl groups to the reaction, and is alkaline, which improves the red shift phenomenon and increases the fluorescence intensity; enhances its negative charge to make each negative group in the molecule The group generates negative electricity to repel each other, lengthens its flatness, and enhances fluorescence intensity.

The following is a comparison experiment on the whiteness difference between the fluorescent whitening agent hexasulfonic acid and the conventional hexasulfonic acid prepared according to the preparation method of the fluorescent whitening agent hexasulfonic acid disclosed in the present invention. The fluorescent whitening agent hexasulfonic acid and conventional hexasulfonic acid prepared by the preparation method were added to the prepared paint to 50g respectively, so that the hexasulfonic acid content of the two were 1%, 2%, 3%, 4 % And 5%. Stir evenly, use a coater to coat, dry at 105°C after completion, and measure the whiteness of each with color Touch PC. The whiteness test values are shown in the table below:

As shown in the above table and Figure 1, the whiteness of the hexasulfonic acid prepared by the present invention is compared with the conventional hexasulfonic acid. The whiteness of the hexasulfonic acid prepared by the present invention is greatly improved, and the usage amount is the traditional hexasulfonic acid. When the sulfonic acid is 86%, the whiteness of the two is similar to that of the traditional hexasulfonic acid. For this reason, the usage can be greatly reduced. When the same ratio, the whiteness can be increased by about 5%.

[Example 2]:

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention uses the following mass ratio of raw materials in this embodiment: 25% aniline 2,5 disulfonic acid monosodium salt; 15% 4,4' -Diaminostilbene-2,2'-disulfonic acid; 15% cyanuric chloride; 15% mixture of sodium glutamate and diisopropanolamine; and 30% alkaline elements.

The mass ratio between the sodium glutamate and diisopropanolamine is 5:1.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention includes the following steps: (a) Add cyanuric chloride to water, stir to dissolve to obtain a cyanuric chloride solution, and then add aniline 2,5 Disulfonic acid monosodium salt solution, followed by adding sodium hydroxide to adjust the pH to 8 to obtain a one-step condensation product; (b) adding 4,4'-diaminostilbene-2,2' to the one-step condensation product -Disulfonic acid solution, then add sodium carbonate to adjust the pH to 8 to obtain a two-step condensation product; and (c) add a mixture of sodium glutamate and diisopropanolamine to the two-step condensation product, and then use basic elements Adjust the pH value to 8-10, and get the finished product.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the step (a) step reaction is 15° C., and the reaction time is 1.2 hours.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction (b) is 50° C., and the reaction time is 2.5 hours.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction (c) is 100° C., and the reaction time is 2.5 hours.

[Example Three]:

In the method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, in this embodiment, the following mass ratio of raw materials is used: 20% amine 2,5 disulfonic acid monosodium salt; 12% 4, 4'-Diaminostilbene-2,2'-disulfonic acid; 13% cyanuric chloride; 12% sodium glutamate and diisopropanolamine mixture; and 43% alkaline elements.

In the above embodiment of the present invention, the mass ratio between the sodium glutamate and diisopropanolamine is 1:1.

The preparation method of this embodiment includes the following steps: (a) Add cyanuric chloride to water, stir to dissolve to obtain a cyanuric chloride solution, then add aniline 2,5 disulfonic acid monosodium salt solution, and then add alkali Adjust the pH value of the sex element to 7 to obtain a one-step condensation product; (b) Add 4,4'-diaminostilbene-2,2'-disulfonic acid solution to the one-step condensation product, and then add alkaline elements to adjust The pH value reaches 7 to obtain a two-step condensation product; and (c) adding a mixture of sodium glutamate and diisopropanolamine to the two-step condensation product, and then adjust the pH value to 9 with a basic element to obtain the finished product.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction in step (a) is 8° C., and the reaction time is 1 hour.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction in step (b) is 40° C., and the reaction time is 2 hours.

The method for preparing the fluorescent whitening agent hexasulfonic acid disclosed in the present invention, wherein the temperature condition of the reaction in step (c) is 95° C., and the reaction time is 2 hours.

The above-mentioned embodiments only exemplarily illustrate the principles and effects of the present invention, and are not used to limit the present invention. Anyone familiar with this technology can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the scope of patent application of the present invention.

Claims (7)

A preparation method of fluorescent whitening agent hexasulfonic acid, which includes the following mass ratios of raw materials: 15-25% aniline 2,5 disulfonic acid monosodium salt; 10-15% 4,4'-diaminodisulfonic acid Styrene-2,2'-disulfonic acid; 10-15% cyanuric chloride; 10-15% sodium glutamate and diisopropanolamine mixture, wherein the sodium glutamate and diisopropanol The mass ratio between amines is 5:1~1:1; and 30-50% of basic elements; its preparation method includes the following steps: (a) Add cyanuric chloride to water and stir to dissolve it. Cyanuric chloride solution, then add aniline 2,5 disulfonic acid monosodium salt solution, and then add alkaline elements to adjust the pH to 6-8 to obtain a one-step condensation product; (b) adding 4 to the one-step condensation product ,4'-diaminostilbene-2,2'-disulfonic acid solution, and then add alkaline elements to adjust the pH to 6-8 to obtain a two-step condensation product; and (c) add to the two-step condensation product An amine mixture of sodium glutamate and diisopropanol, then adjust the pH to 8-10 with alkaline elements. The method for preparing the fluorescent whitening agent hexasulfonic acid according to claim 1, wherein the reaction temperature condition in step (a) is 0-15°C, and the reaction time is 0.8-1.2 hours. The method for preparing the fluorescent whitening agent hexasulfonic acid according to claim 1, wherein the temperature condition of the reaction in step (b) is 30-50° C., and the reaction time is 1.5-2.5 hours. The method for preparing the fluorescent whitening agent hexasulfonic acid according to claim 1, wherein the reaction temperature in step (c) is 90-100° C., and the reaction time is 1.5-2.5 hours. The method for preparing the fluorescent whitening agent hexasulfonic acid according to claim 1, wherein the basic element refers to sodium carbonate, sodium hydroxide or sodium bicarbonate. The method for preparing the fluorescent whitening agent hexasulfonic acid according to claim 1, wherein the basic element refers to basic particles, powders or solutions. A finished product manufactured according to the method for preparing the fluorescent whitening agent hexasulfonic acid according to any one of claims 1 to 6.

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