Preparation method and application of aminobutyric acid stilbene polyvinyl alcohol fluorescent whitening agent

Abstract

The invention provides a preparation method and application of an aminobutyric acid stilbene polyvinyl alcohol fluorescent whitening agent, and the preparation method comprises the following steps: slowly dripping a solution formed by DSD acid, ice water and 10% NaOH into cyanuric chloride-ice water mixed liquor, controlling the temperature to be 0-5 DEG C, reacting for 2 hours, then adding 4-aminobutyric acid, adjusting the pH value to be 7-8 by using 10% NaOH, heating to 40-45 DEG C, and reacting for 4 hours; adding a polyvinyl alcohol 1788 aqueous solution with the mass fraction of 5%, maintaining the pH value to be 8-9 by using a 10% NaOH solution, heating to 90-95 DEG C, and reacting for 8 hours; and cooling to room temperature, adding absolute ethyl alcohol, stirring overnight, carrying out suction filtration, washing for three times with absolute ethyl alcohol, and drying at 45 DEG C to obtain the aminobutyric acid stilbene polyvinyl alcohol fluorescent whitening agent. According to the present invention, with the application of the paper sheet with the whiteness (CIE) of 79.38, the whiteness (CIE) is increased to 126.34-128.77, the whiteness value (CIE) is increased by 46.96-49.39, and the treated paper sheet is smoother and flat, and has the surface finishing effect;

Description

Technical Field

[0001] The present invention relates to a fluorescent whitening agent, and particularly to a preparation method and application of a diphenylstyrene polyvinyl alcohol fluorescent whitening agent of aminobutyric acid. Background Art

[0002] A fluorescent whitening agent is a chemical additive that enhances the whiteness and brightness of materials by absorbing invisible ultraviolet light and emitting blue-violet fluorescence, making them appear whiter. Fluorescent whitening agents are widely used in many fields such as textiles, papermaking, detergents, coatings, and plastics, and can also be used as fluorescent probes, fluorescent sensors, dye exciters, and anti-counterfeiting printing in high-tech fields. The parent structure of diphenylstyrene fluorescent whitening agents contains double bonds and is extremely prone to photo-induced isomerization, resulting in poor practical effects. The structure of polyvinyl alcohol 1788 contains a large number of hydroxyl groups, which can effectively improve the water solubility of the fluorescent whitening agent and the surface strength of paper. In addition, the long-chain structure of polyvinyl alcohol 1788 greatly increases the steric hindrance, effectively inhibiting the cis-trans isomerization of diphenylstyrene fluorescent whitening agents, thereby improving the light fastness.

[0003] In summary, it is particularly urgent and necessary to research and develop a new type of high-performance polyvinyl alcohol fluorescent whitening agent and use it in the production of high-whiteness and high-quality paper. After retrieval, the preparation method and application of a diphenylstyrene polyvinyl alcohol fluorescent whitening agent of aminobutyric acid have not been reported yet, and the market demand is very urgent. Summary of the Invention

[0004] The object of the present invention is to provide a preparation method and application technology of a diphenylstyrene polyvinyl alcohol fluorescent whitening agent of aminobutyric acid, which can significantly improve the whiteness and flatness of paper and increase the quality and added value of paper. The preparation method and application technology of the diphenylstyrene polyvinyl alcohol fluorescent whitening agent of aminobutyric acid of the present invention are composed of the following steps:

[0005] (1) Stir 1.35 mmol of DSD acid, 15 mL of ice water, and 10% NaOH until clear;

[0006] (2) Place 2.7 mmol of cyanuric chloride and 15 mL of ice water in a reactor, stir in an ice bath, slowly drop (1) into it, and control the temperature at 0 - 5 °C for 2 h;

[0007] (3) Add 2.7 - 3.2 mmol of 4-aminobutyric acid, adjust the pH = 7 - 8 with 10% NaOH solution, raise the temperature to 40 - 45 °C, and react for 4 h;

[0008] (4) Add an aqueous solution of polyvinyl alcohol 1788 with a mass fraction of 4.5 - 5%, maintain the pH = 8 - 9 with 10% NaOH solution, raise the temperature to 90 - 95 °C, and react for 8 h;

[0009] (5) Cool to room temperature, add anhydrous ethanol and stir overnight, filter by suction, wash three times with anhydrous ethanol, and dry at 45 °C to obtain the amino-butyric acid stilbene polyvinyl alcohol fluorescent brightener;

[0010] (6) Prepare aqueous solutions of different concentrations of the amino-butyric acid stilbene polyvinyl alcohol fluorescent brightener, dye and surface-treat the paper, and dry it naturally to obtain high-whiteness and high-flatness paper.

[0011] The amount of 4-aminobutyric acid described in the above step (3) is preferably 2.7 - 3.2 mmol.

[0012] The mass fraction of the polyvinyl alcohol 1788 aqueous solution described in the above step (4) is preferably 4.5 - 5%.

[0013] The temperature described in the above step (4) is preferably 90 - 95 °C.

[0014] The concentration of the amino-butyric acid stilbene polyvinyl alcohol fluorescent brightener described in the above step (6) is preferably 0.5 - 1.0%.

[0015] Experimental data show that the paper with a whiteness (CIE) of 79.38 is treated by the technology of the present invention, and the whiteness (CIE) is increased to 126.34 - 128.77, and the whiteness value (CIE) is increased by 46.96 - 49.39. The treated paper is smoother and flatter, and has the function of surface finishing.

[0016] By adopting the preparation method and application technology of the amino-butyric acid stilbene polyvinyl alcohol fluorescent brightener of the present invention, the problems that the parent structure of the stilbene fluorescent brightener contains double bonds and is extremely prone to photoisomerization and the practical effect is poor can be effectively solved, and the whiteness and flatness of the paper are significantly improved; by adopting the preparation method and application technology of the amino-butyric acid stilbene polyvinyl alcohol fluorescent brightener of the present invention, dyeing and treating the paper can achieve the dual effects of whitening and surface finishing, improve the quality and added value of the paper, and have great economic value and popularization value. The present invention will be further described below with reference to the examples. Specific Embodiments

[0017] Example 1:

[0018] (1) Stir 1.35 mmol of DSD acid, 15 mL of ice water and 10% NaOH until clear;

[0019] (2) Place 2.7 mmol of cyanuric chloride and 15 mL of ice water into the reactor, stir in an ice bath, slowly drop (1) into it, and control the temperature at 0 - 5 °C and react for 2 h;

[0020] (3) Add 2.7 mmol of 4-aminobutyric acid, adjust the pH = 7 - 8 with 10% NaOH solution, raise the temperature to 40 - 45 °C, and react for 4 h;

[0021] (4) Add an aqueous solution of polyvinyl alcohol 1788 with a mass fraction of 5%, maintain the pH = 8 - 9 with 10% NaOH solution, heat up to 95 °C and react for 8 h;

[0022] (5) Cool to room temperature, add absolute ethanol and stir overnight, filter by suction, wash three times with absolute ethanol, dry at 45 °C to obtain the fluorescent whitening agent of diphenylstyrene polyvinyl alcohol aminobutyrate;

[0023] (6) Prepare an aqueous solution with a concentration of 1.0% of the fluorescent whitening agent of diphenylstyrene polyvinyl alcohol aminobutyrate, dye and treat the paper with a whiteness (CIE) of 79.38. The whiteness (CIE) is increased to 128.77, the whiteness value (CIE) is increased by 49.39, and the treated paper is smoother and flatter, with a surface finishing effect.

[0024] Example 2:

[0025] (1) Stir 1.35 mmol of DSD acid, 15 mL of ice water and 10% NaOH until clear;

[0026] (2) Place 2.7 mmol of cyanuric chloride and 15 mL of ice water into the reactor, stir in an ice bath, slowly drop (1) into it, and control the temperature at 0 - 5 °C and react for 2 h;

[0027] (3) Add 3.2 mmol of 4-aminobutyric acid, adjust the pH = 7 - 8 with 10% NaOH solution, heat up to 40 - 45 °C and react for 4 h;

[0028] (4) Add an aqueous solution of polyvinyl alcohol 1788 with a mass fraction of 4.5%, maintain the pH = 8 - 9 with 10% NaOH solution, heat up to 90 °C and react for 8 h;

[0029] (5) Cool to room temperature, add absolute ethanol and stir overnight, filter by suction, wash three times with absolute ethanol, dry at 45 °C to obtain the fluorescent whitening agent of diphenylstyrene polyvinyl alcohol aminobutyrate;

[0030] (6) Prepare an aqueous solution with a concentration of 0.5% of the fluorescent whitening agent of diphenylstyrene polyvinyl alcohol aminobutyrate, dye and treat the paper with a whiteness (CIE) of 79.38. The whiteness (CIE) is increased to 126.34, the whiteness value (CIE) is increased by 46.96, and the treated paper is smoother and flatter, with a surface finishing effect.

[0031] Through the dyeing and whitening experiment test, the fluorescent whitening agent of diphenylstyrene polyvinyl alcohol aminobutyrate of the present invention has a significant whitening and surface finishing effect on paper.

[0032] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. The preparation method and application of aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent are composed of the following steps: (1) 1.35 mmol DSD acid, 15 mL ice water and 10% NaOH were stirred until clear; (2) 2.7 mmol of cyanuric chloride and 15 mL of ice water were placed in a reactor, stirred in an ice bath, and (1) was slowly added dropwise, and the temperature was controlled at 0-5°C for 2 h; (3) Add 2.7-3.2 mmol 4-aminobutyric acid, adjust pH to 7-8 with 10% NaOH solution, raise the temperature to 40-45°C, and react for 4 hours; (4) adding a 4.5-5% mass fraction of polyvinyl alcohol 1788 aqueous solution, maintaining the pH value at 8-9 with a 10% NaOH solution, and heating to 90-95° C. for reaction for 8 h; (5) cooling to room temperature, adding anhydrous ethanol and stirring overnight, filtering, washing three times with anhydrous ethanol, and drying at 45° C. to obtain aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent; (6) The aminobutyric acid distyrene polyvinyl alcohol fluorescent brightener is prepared into aqueous solutions of different concentrations, and the paper is dyed and surface treated, and then naturally dried to obtain high-whiteness and high-smoothness paper.

2. The preparation method and application of the aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent according to claim 1, characterized in that: The amount of 4-aminobutyric acid in step (3) is preferably 2.7 to 3.2 mmol.

3. The preparation method and application of aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent according to claim 1, characterized in that: The mass fraction of the polyvinyl alcohol 1788 aqueous solution in step (4) is preferably 4.5-5%.

4. The preparation method and application of the aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent according to claim 1, characterized in that: The temperature in step (4) is preferably 90-95°C.

5. The preparation method and application of the aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent according to claim 1, characterized in that: The concentration of the aminobutyric acid distyrene polyvinyl alcohol fluorescent whitening agent described in step (6) is preferably 0.5 to 1.0%.