Preparation method and application of photochromic dye modified spandex fiber

Abstract

The invention relates to the technical field of polyurethane fibers, in particular to a photochromic dye modified spandex fiber, when a color-changing group spiropyrane group is illuminated, a molecular structure and an electronic configuration are isomerized and rearranged to present a new color, and the spiropyrane color-changing group is grafted to a polyurethane long chain, so that the photochromic dye modified spandex fiber is obtained. Compared with a simple dyeing or physical blending addition spinning method, the photochromic spandex fiber has the advantages that the photochromic spandex fiber is deepened in color and becomes purple from pink or light purple, the photochromic spandex fiber gradually fades into light purple or pink after light is lost, and the photochromic spandex fiber is better in stability and can be used for washing clothes repeatedly in the process of washing the clothes repeatedly. Compared with the prior art, the polyurethane has the advantages that the original color can still be kept, the phenomena of color change, color fading and the like are avoided, and spiropyrane groups belonging to hard-segment materials are grafted at two ends of the polyurethane, so that the glass-transition temperature of the polyurethane is increased, and the spandex fiber has better thermal stability.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane fibers, in particular to a preparation method and application of photochromic dye-modified spandex fibers. Background Art

[0002] With the continuous development of society, science and technology, humanities and art are constantly changing, and people's clothing styles are becoming more and more diverse. In order to meet people's novel and unique aesthetics, fabrics of various colors have come into being. Among them, color-changing fabrics are fabrics that can change color due to changes in external conditions such as light, temperature, humidity, and force. This is because the color-changing functional group can undergo a reversible conversion between two different structures. Photochromic dyes are very good color-changing fabric dyes that can change color when exposed to light and return to their original color in the dark. They are very interesting fabric dyes.

[0003] Photochromic groups usually include spirooxazines, dithizones, Schiff bases, azobenzenes, spiropyrans, etc. Among them, spiropyrans are often used as photochromic dyes due to their stable chemical properties and obvious photochromic properties. Polyurethane fiber, also known as spandex, is a fiber with excellent elasticity and is also often used for spinning fabrics. Since the color-changing dyes have poor dyeing effects, they are usually physically blended in the spinning solution. However, simple blending in the spinning solution is still prone to fading during washing and use, resulting in color difference and affecting the appearance of the clothes. The fading phenomenon can be well prevented by grafting. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for preparing and applying spandex fiber modified with a photochromic dye, which solves the problems that spandex does not have photochromic properties and is prone to fading due to simple blending.

[0005] To achieve the above object, the present invention provides the following technical solution: A method for preparing photochromic dye-modified spandex fiber comprises the following steps: (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, heating to react, cooling to room temperature, precipitating, filtering, and separating and purifying by column chromatography to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are mixed evenly, dibutyltin dilaurate is added, and the mixture is reacted at 60-80°C for 4-6 hours. Then 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, 1,4-butylene di(thioglycolate) is added, the mixture is cooled to 50-60°C, acetone is added to adjust the viscosity, triethylamine is added, and after stirring evenly, N,N-dimethylacetamide is added and the mixture is dispersed to obtain a thiol-terminated polyurethane dispersion. (4) adding an alkenyl spiropyran derivative to a thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, mechanically stirring, irradiating with ultraviolet light to carry out a thiol-ene click reaction, filtering, degassing, and aging to obtain a spiropyran-modified polyurethane spinning solution; (5) Magnesium stearate is added to the spinning solution of the terminal spiropyran modified polyurethane, and dry spinning is performed in a spinning device. The obtained fiber is mixed with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, and filtered to obtain photochromic dye-modified spandex fiber.

[0006] Preferably, in step (2), the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:30-50:160-200:50-65.

[0007] Preferably, the atmosphere for heating the reaction in step (2) is a nitrogen atmosphere, the reaction temperature is 100-120° C., and the reaction time is 20-30 h.

[0008] Preferably, in the step (3), the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol in the step (3) is 100:85-105:0.2-1:10-20:100-140.

[0009] Preferably, in step (4), the mass ratio of the terminal mercapto polyurethane, the alkenyl-containing spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:0.8-1.5:0.01-0.03.

[0010] Preferably, the ultraviolet light intensity of the thiol-ene click reaction in step (4) is 45-60 mW / cm 2 The irradiation time is 25-60min.

[0011] Preferably, in step (5), the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:3-5:10-20.

[0012] Compared with the prior art, the present invention has the following experimental principles and beneficial technical effects: The photochromic dye modified spandex fiber comprises the following steps: using 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid as reactants to prepare bromine-containing spiropyran of a color-changing group; removing bromine on the spiropyran and hydrogen on divinylbenzene to obtain alkenyl-containing spiropyran derivatives; using polyether diol and isophorone diisocyanate as monomers; adding di(thioglycolic acid)-1,4-butylene glycol; and performing a thiol-isocyanate click reaction to obtain a thiol-terminated polyurethane; adding an alkenyl-containing spiropyran derivative; and performing a thiol-ene click reaction under ultraviolet light to obtain a spiropyran grafted modified polyurethane; and finally performing dry spinning to obtain a photochromic dye modified spandex fiber. In dye-modified spandex fibers, the CO bond of the spiropyran group breaks when exposed to light, and the molecular structure and electronic configuration undergo isomerization and rearrangement, thereby causing a red shift in the absorption wavelength and presenting a new color, which is then re-cyclized in a dark environment. By grafting the spiropyran color-changing group onto the long chain of polyurethane, the spandex fiber is endowed with photochromic properties. Under the stimulation of light, the color deepens from pink or lavender to purple, and gradually fades to lavender or pink after the light is lost. Under the alternation of light and dark conditions, a color-changing effect with good visual effects can be produced, which can be applied to the weaving of fashionable clothing to increase the added value of clothing.

[0013] The photochromic dye-modified spandex fiber grafts the spiropyran color-changing group onto the polyurethane long chain by means of a mercapto-ene click reaction. Compared with a simple dyeing or physical blending and spinning method, the fiber has better stability, and can maintain the original color during repeated washing of the clothing without discoloration or fading. Compared with a printing method with a hard feel and poor elasticity, a method of directly grafting and dyeing the fiber has a better feel and better elasticity than printing. Compared with exposure to an air environment, a method of grafting into a polyurethane matrix also reduces the contact of the spiropyran group with a complex external environment, thereby improving the fatigue resistance of the spiropyran group, and making the group have better fatigue resistance and a more lasting color-changing effect.

[0014] The photochromic dye modified spandex fiber has spiropyran groups belonging to hard segment materials grafted on both ends of polyurethane. Since the glass transition temperature of the spiropyran groups is relatively high, the glass transition temperature of the polyurethane is increased, so that the spandex fiber has better thermal stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is the reaction formula for synthesizing bromine-containing spiropyran; Figure 2 This is the reaction formula for synthesizing alkenyl-containing spiropyran derivatives. DETAILED DESCRIPTION

[0016] To achieve the above object, the present invention provides the following technical solution: The method for preparing a photochromic dye-modified spandex fiber is as follows: (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:30-50:160-200:50-65, heating to react, the reaction atmosphere is a nitrogen atmosphere, the reaction temperature is 100-120°C, the reaction time is 20-30h, cooling to room temperature, precipitating, filtering, and column chromatography separation and purification to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are mixed evenly, dibutyltin dilaurate is added, and the mixture is reacted at 60-80°C for 4-6h, and then 2,2-dihydroxymethylpropionic acid is added, and the mixture is kept warm for reaction, followed by adding di(thioglycolic acid)-1,4-butylene glycol, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:85-105:0.2-1:10-20:100-140, and the mixture is cooled to 50-60°C, and acetone is added to adjust the viscosity, and then triethylamine is added, and after stirring evenly, N,N-dimethylacetamide is added for dispersion to obtain a thiol-terminated polyurethane dispersion; (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:0.8-1.5:0.01-0.03, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 45-60mW / cm 2 , the irradiation time is 25-60min, filtering, degassing and aging to obtain a terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:3-5:10-20, and then filtering to obtain photochromic dye modified spandex fiber. Example 1

[0017] (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:30:160:50, heating for reaction, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 100°C, the reaction time is 20 hours, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 60°C for 4 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:85:0.2:10:100. The mixture is cooled to 50°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added for dispersion to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:0.8:0.01, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 45mW / cm 2 , the irradiation time is 25 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Magnesium stearate is added to the spinning solution of the terminal spiropyran modified polyurethane, and dry spinning is performed in a spinning device. The obtained fiber is mixed with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:3:10, and then filtered to obtain photochromic dye modified spandex fiber. Example 2

[0018] (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:35:170:53, heating for reaction, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 105°C, the reaction time is 24h, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain alkenyl-containing spiropyran derivatives; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 65°C for 4.5 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:90:0.4:13:110. The mixture is cooled to 55°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added and dispersed to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:1:0.015, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 50mW / cm 2 , the irradiation time is 35 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:3.5:13, and filtering to obtain photochromic dye modified spandex fiber. Example 3

[0019] (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:40:180:55, heating for reaction, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 110°C, the reaction time is 25h, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain alkenyl-containing spiropyran derivatives; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 70°C for 5 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:95:0.6:15:120. The mixture is cooled to 55°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added and dispersed to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:1.2:0.02, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 50mW / cm 2 , the irradiation time is 45 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:4:15, and then filtering to obtain photochromic dye modified spandex fiber. Example 4

[0020] (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:45:190:60, heating for reaction, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 115°C, the reaction time is 28h, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain alkenyl-containing spiropyran derivatives; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 75°C for 5 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:100:0.8:18:130. The mixture is cooled to 55°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added and dispersed to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:1.3:0.025, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 60mW / cm 2 , the irradiation time is 50 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:4.5:18, and filtering to obtain photochromic dye modified spandex fiber. Example 5

[0021] (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:50:200:65, heating for reaction, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 120°C, the reaction time is 30 hours, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 80°C for 6 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:105:1:20:140. The mixture is cooled to 60°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added for dispersion to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:1.5:0.03, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 60mW / cm 2 , the irradiation time is 60 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:5:20, and filtering to obtain photochromic dye modified spandex fiber.

[0022] Comparative Example 1 (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, wherein the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:20:140:40, heating to react, the reaction atmosphere is nitrogen atmosphere, the reaction temperature is 100°C, the reaction time is 20 hours, cooling to room temperature, precipitating, filtering, column chromatography separation and purification, to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are uniformly mixed, dibutyltin dilaurate is added, and the mixture is reacted at 60°C for 4 hours. Then, 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, di(thioglycolic acid)-1,4-butylene glycol is added, wherein the mass ratio of the polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:75:0.15:8:90. The mixture is cooled to 50°C, acetone is added to adjust the viscosity, triethylamine is added, and after uniform stirring, N,N-dimethylacetamide is added and dispersed to obtain a thiol-terminated polyurethane dispersion. (4) Adding the alkenyl spiropyran derivative to the thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, wherein the mass ratio of the thiol-terminated polyurethane, the alkenyl spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:0.6:0.005, mechanically stirring, and irradiating with ultraviolet light to carry out thiol-ene click reaction, the ultraviolet light intensity is 45mW / cm 2 , the irradiation time is 25 min, filtering, degassing and aging to obtain the terminal spiropyran modified polyurethane spinning solution; (5) Adding magnesium stearate to the spinning solution of the terminal spiropyran modified polyurethane, performing dry spinning in a spinning device, mixing the obtained fiber with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, wherein the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:2:8, and filtering to obtain photochromic dye modified spandex fiber.

[0023] The color-changing spandex fibers of the examples and comparative examples were subjected to a TSY-42 differential scanning calorimeter at a heating rate of 10°C / min in a temperature range of -60°C to 80°C, and ordinary spandex prepared in the same manner was used as a control.

[0024]

[0025] The color-changing spandex fibers of the embodiment and the comparative example were placed in a dark environment for 15 minutes, then irradiated with a 365nm ultraviolet lamp for 10 minutes, and then placed in a dark environment to avoid light for 15 minutes, and the colors were observed respectively.

[0026]

Claims

1. A photochromic dye-modified spandex fiber, characterized in that: The method for preparing a photochromic dye-modified spandex fiber comprises the following steps: (1) adding 2,3,3-trimethyl-3H-indole and 5-bromosalicylic acid to an ethanol solvent, then adding sodium hydroxide, heating for reaction, separating and purifying to obtain bromine-containing spiropyran; (2) dissolving the bromine-containing spiropyran, divinylbenzene, potassium phosphate and palladium acetate in N,N-dimethylacetamide solvent, heating to react, cooling to room temperature, precipitating, filtering, and separating and purifying by column chromatography to obtain an alkenyl-containing spiropyran derivative; (3) After the polyether diol and isophorone diisocyanate are mixed evenly, dibutyltin dilaurate is added, and the mixture is reacted at 60-80°C for 4-6 hours. Then 2,2-dihydroxymethylpropionic acid is added and the mixture is kept warm for reaction. Then, 1,4-butylene di(thioglycolate) is added, the mixture is cooled to 50-60°C, acetone is added to adjust the viscosity, triethylamine is added, and after stirring evenly, N,N-dimethylacetamide is added and the mixture is dispersed to obtain a thiol-terminated polyurethane dispersion. (4) adding an alkenyl spiropyran derivative to a thiol-terminated polyurethane dispersion, and then adding 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, mechanically stirring, irradiating with ultraviolet light to carry out a thiol-ene click reaction, filtering, degassing, and aging to obtain a spiropyran-modified polyurethane spinning solution; (5) Magnesium stearate is added to the spinning solution of the terminal spiropyran modified polyurethane, and dry spinning is performed in a spinning device. The obtained fiber is mixed with N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine and rubber latex, and filtered to obtain photochromic dye-modified spandex fiber.

2. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: In the step (2), the mass ratio of divinylbenzene, bromine-containing spiropyran, potassium phosphate and palladium acetate is 100:30-50:160-200:50-65.

3. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: The atmosphere for heating the reaction in step (2) is a nitrogen atmosphere, the reaction temperature is 100-120° C., and the reaction time is 20-30 hours.

4. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: In the step (3), the mass ratio of polyether diol, isophorone diisocyanate, dibutyltin dilaurate, 2,2-dihydroxymethylpropionic acid and di(thioglycolic acid)-1,4-butylene glycol is 100:85-105:0.2-1:10-20:100-140.

5. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: In the step (4), the mass ratio of the terminal mercapto polyurethane, the alkenyl-containing spiropyran derivative and the 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is 100:0.8-1.5:0.01-0.

03.

6. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: The ultraviolet light intensity of the thiol-ene click reaction in step (4) is 45-60 mW / cm 2 , the irradiation time is 25-60min.

7. The photochromic dye-modified spandex fiber according to claim 1, characterized in that: In the step (5), the mass ratio of the spiropyran modified polyurethane spinning solution, the lubricant magnesium stearate and the antioxidant N-(1,3-dimethyl)butyl-N'-phenyl-p-phenylenediamine is 100:3-5:10-20.

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