CN111286211B - Sun-proof blue acid dye and preparation method thereof - Google Patents

Abstract

The invention discloses a sun-proof blue acid dye, which has the following structural general formula:

Description

Sun-proof blue acid dye and preparation method thereof

Technical Field

The invention relates to a sun-proof blue acid dye and a preparation method thereof.

Background

In 2015, a indigo dye called indigo was produced by researchers at utah state university in usa using escherichia coli and mass production was achieved. Indigo dye of indigo has pure blue hue, and can be used as coloring agent in food, beverage or cosmetic after purification. The blue natural dye is more and more widely concerned by dye researchers due to the characteristics of easy mass production, no toxicity, no harm, no pollution and the like. However, the dye structure has two primary amine groups, so that the light fastness is poor, and the obtained dye has low light fastness when being used for a dye color body. Furthermore, indigo is poorly soluble in solvents and only poorly soluble in DMF and DMSO, making it difficult to achieve staining with aqueous media. Therefore, it is possible to improve the solubility and light stability of the dye by structurally modifying the dye, and a variety of dyes having practical value is developed.

The acid dye is a water-soluble dye containing sulfonate or carboxylate substituent groups in dye molecules, is also called as an anionic dye, can be combined with amino groups in protein fiber (wool, silk and the like) molecules by ionic bonds under an acidic condition, and is suitable for being used under an acidic, weak-acid or neutral condition.

A blue acidic dye and its preparing process (CN201811221115.8) features that the indigo dye is reacted with chlorobenzyl sulfonic acid to obtain water-soluble dye, which can efficiently dye protein fibres and increase the dye-uptake and colour fastness of fibres. However, the light fastness of the dye modified by the method still cannot reach an excellent level, and is only 5-5.5.

Disclosure of Invention

The invention aims to solve the technical problem of providing a light-fast blue acid dye and a preparation method thereof, wherein the dye has higher solubility in water, so that the dye can realize high-efficiency dyeing on protein fibers in a water system, the dye uptake and color fastness of the dye on the fibers are improved, and the improvement on the light-fast fastness is particularly remarkable.

In order to solve the technical problems, the invention provides a sun-proof blue acid dye, the molecular structure of which contains a sodium sulfonate group and an o-hydroxyphenyltriazole structure with an ultraviolet absorption function, and the general structural formula of the dye is as follows:

r is H or sec-butyl.

As an improvement of the light-fast blue acid dye, the structural formula is as follows:

the invention also provides a preparation method of the sunproof blue acid dye, which is prepared by reacting indigo dye with chlorine-containing water-soluble benzotriazole ultraviolet absorbent, and specifically comprises the following steps:

1) grinding the indigo dye (sieving with a 400-mesh sieve) and dispersing in water to obtain a dye suspension;

dissolving a chlorine-containing water-soluble benzotriazole ultraviolet absorbent in water to obtain an ultraviolet absorbent solution;

mixing the dye suspension, an ultraviolet absorbent solution and potassium carbonate powder serving as an acid-binding agent, and adding the mixture into a hydrothermal reaction kettle; carrying out heat preservation reaction for 12-16 hr under the condition of oil bath at the temperature of (110 +/-10);

the indigo dye: chlorine-containing water-soluble benzotriazole ultraviolet absorbers: potassium carbonate in a molar ratio of 1:2: 2;

the structural formula of the indigo dye is as follows:

the chlorine-containing water-soluble benzotriazole ultraviolet absorbent is

(CAS：92484-50-9)、

(CAS：1220633-82-8)；

2) Adding sodium chloride into the reaction product solution obtained in the step 1) until the sodium chloride is saturated, separating out a product, filtering, removing salt in the product by adopting a DMF-ether method, and drying the product to obtain the light-fast blue acid dye.

As an improvement of the preparation method of the present invention, in step 1) of the present invention:

adding 20 plus or minus 5mL of water into 0.01mol of indigo dye to obtain dye suspension;

40 plus or minus 10ml of water is matched with 0.02mol of chlorine-containing water-soluble benzotriazole ultraviolet absorbent to obtain ultraviolet absorbent solution.

According to the invention, two benzotriazole type ultraviolet absorption segments (the reaction formula is shown as the following formula) containing water-soluble sodium sulfonate groups are introduced to two primary amine groups of the indigo dye, and simultaneously, the water solubility and the light stability of the dye are improved, so that the water-soluble acid dye with excellent light fastness is developed, and the water-soluble acid dye can be applied to dyeing of protein fibers such as wool.

The invention discovers that: the introduction of an aromatic ring system containing ultraviolet absorption segments into indigo dye molecules and the increase of molecular weight can improve Van der Waals force between dye molecules and fiber macromolecules, facilitate the improvement of dye uptake and color fastness of the dye to fibers, and particularly obviously improve light fastness. In addition, sulfonic acid groups are introduced into the indigo structure to improve the water solubility of the dye, so that the modified indigo dye meets the structural characteristics of an acid dye and is used for dyeing protein fibers. Theoretically, primary amino (-NH)₂) After conversion to a secondary amino group (-NH-), the electron cloud density on N is increased, and photo-oxidation reaction is likely to occur, i.e., the light fastness should be decreased. However, in the invention, two ultraviolet absorption fragments with extremely high efficiency are introduced into molecules, so that the damage of ultraviolet to the dye can be inhibited, and the light fastness of the blue acid dye prepared by the invention is obviously improved and reaches an excellent grade.

According to the invention, the affinity and water solubility of the dye to protein fibers can be improved by simultaneously introducing the aromatic ring and the sulfonic acid group into the dye structure, and the applicability of the dye to the protein fibers is improved. In addition, two ultraviolet absorption segments are introduced by modifying primary amine groups in the structure of the indigo dye, so that the light fastness of the dye is obviously improved. The dye disclosed by the invention is simple in synthesis process, and can be prepared by condensing indigo dye and chlorine-containing water-soluble benzotriazole ultraviolet absorbent. The developed blue acid dye has excellent color fastness to protein fibers, and has wide application prospect.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto:

example 1, a method for preparing a light fast blue acid dye, sequentially comprising the following steps:

1) adding 0.01mol of ground indigo dye (400 meshes) and 20mL of water into a 500mL hydrothermal reaction kettle, and stirring at room temperature to form a dye suspension for later use;

2) 0.02mol of chlorine-containing water-soluble benzotriazole ultraviolet absorber

Dissolving in 40ml water to obtain ultraviolet absorbent solution;

adding an ultraviolet absorbent solution into the dye suspension obtained in the step 1), then adding 0.02mol of potassium carbonate as an acid-binding agent, and reacting for 16hr at 110 ℃;

3) after the reaction is finished, adding 30g (0.504mol) of sodium chloride solid into the reaction product solution, wherein the sodium chloride is saturated, salting out a dye product, and filtering to obtain a filter cake which is a salt-containing dye;

4) removing salt in the product by adopting a DMF-diethyl ether method, collecting and drying the product, wherein the method comprises the following steps:

DMF-Ether method: taking 2g of the salt-containing dye obtained in the step 3), dissolving in 15mL of DMF, filtering to remove salt, adding 100mL of anhydrous ether into the filtrate to separate out the dye, filtering, collecting a filter cake, and drying at room temperature to constant weight; obtaining the sun-proof blue acid dye I.

The structural formula of the sun-proof blue acid dye I is as follows:

¹H NMR(400MHz,DMSO-d6)：δ11.08(s,2H),10.04(s,2H),7.80(m,6H),7.18(s,2H),7.01(d,2H),6.65(d,2H),6.42(s,2H),4.03(s,2H)；ESI MS(m/z,％):412.0([M-2Na]/2^-,100)。

example 2, a method for preparing a light fast blue acid dye, sequentially comprising the following steps:

1) adding 0.01mol of ground indigo dye (400 meshes) and 25mL of water into a 500mL hydrothermal reaction kettle, and stirring at room temperature to form a dye suspension for later use;

2) 0.02mol of chlorine-containing water-soluble benzotriazole ultraviolet absorber

Dissolving in 45ml water to obtain ultraviolet absorbent solution;

adding an ultraviolet absorbent solution into the dye suspension obtained in the step 1), then adding 0.02mol of potassium carbonate as an acid-binding agent, and reacting for 12hr at 110 ℃;

3) after the reaction is finished, adding 30g (0.504mol) of sodium chloride solid into the reaction product solution, wherein the sodium chloride is saturated, salting out a dye product, and filtering to obtain a filter cake which is a salt-containing dye;

4) and removing salt in the product by adopting a DMF-ether method, collecting and drying the product to obtain the light-fast blue acid dye II.

The structural formula of the sun-proof blue acid dye II is as follows:

¹H NMR(400MHz,DMSO-d6)：δ11.12(s,2H),9.98(s,2H),7.73(d,2H),7.58(m,4H),7.19(s,2H),6.63(d,2H),6.42(s,2H),4.05(s,2H),2.94(m,2H),1.62(m,4H),1.33(d,6H),0.96(t,6H)；ESI MS(m/z,％):468.1([M-2Na]/2^-,100)。

the application of the light fast blue acid dye of the present invention in protein fiber dyeing is illustrated by experiments below.

Experiment 1,

Experimental method described with reference to 201811221115.8: 1kg of wool fabric is taken, and the pH value is adjusted to 4.5-5.0 by acetic acid according to a sun-proof blue acid dye 2% owf and anhydrous sodium sulphate 5% owf, wherein the bath ratio is 1: 20.

After dyeing is finished, taking out a dyed cloth sample, washing, combining dyeing residual liquid and washing liquid, fixing the absorbance of a volume measuring device, and solving the dye uptake of the dye by utilizing the Lambert-beer law; and the soaping fastness, the dry rubbing fastness, the wet rubbing fastness, the sublimation fastness and the light fastness of the dyed cloth sample are measured. The results are shown in Table 1.

The light-fast blue acid dye is changed into indigo dye, and the rest is the same as above. The results are shown in Table 1: the dye uptake of the dye was 4.7%, and the dyeing residue changed from blue to brown (due to oxidation of the dye) after dyeing, indicating that the oxidation resistance of the indigo dye was not good enough. Because indigo dyes are poorly soluble in water and have low affinity for wool fibers, dark colors cannot be dyed on wool fabrics, and the various colorfastnesses cannot be rated.

As can be seen from Table 1, the modified dyes of the present invention have excellent color fastness, especially greatly improved light resistance stability. The light fastness measured by the dyes I, II in the embodiments 1 and 2 of the invention exceeds 7 grades, and reaches an excellent grade, which shows that the light fastness of the modified dyes on wool is good, and the modified dyes can be used as acid dyes for dyeing wool fabrics, and have high dye uptake and excellent color fastness.

TABLE 1 dyeing data of wool fabrics with blue acid dyes

Experiment 2 inhibition of photooxidation reaction and solubility in water

Experimental method described with reference to 201811221115.8: a DMF solution of the dye I, II was prepared with equimolar concentrations (0.05mol/L) of indigo and the light fast blue acid dye, and after 2 hours of irradiation under the same illumination conditions (500W mercury lamp), the rate of dye fading was calculated from the rate of change of absorbance at the maximum absorption wavelength of the dye, and the specific data are shown in Table 2. Solubility in water of indigo, fast blue acid dye I, II is shown in Table 2.

TABLE 2 dye solubility and fade rate after exposure to light in DMF solution

Dye material	Solubility in Water (g/L)	Fading rate (%)
			Indigoidine	0.013	87.4
I (example 1)	87.5	0.8
			II (example 2)	75.4	0.3
III (comparative example 1)	108	3.5

As can be seen from Table 2, after modification, the light resistance of the dye is greatly improved, the fading rate of the dye after long-term high-intensity illumination is extremely low (< 1%), and the light stabilization effect of the ultraviolet absorption fragment on the indigo color body is very obvious. In addition, sulfonic groups introduced into the molecular structure endow the dye with good water solubility, so that the dye meets the application requirements of acid dyes.

Comparative examples 1,

The blue acid dye III with the best dyeing property and fastness in the blue acid dye and the preparation method (CN201811221115.8) is selected:

the water-soluble blue dye III was detected according to the above experiments 1 and 2, and the results are shown in tables 1 and 2.

Dye III lacks uv absorbing moieties in its structure and has a lower molecular weight, resulting in lower affinity for fiber and lower light fastness than the dye I, II of the present invention. In addition, the other color fastness properties and the light oxidation resistance were also significantly lower than those of the dye I, II.

Comparative examples 2,

Compared with the dye I, the dye has the advantages that two methylene groups are added in the middle of an indigo imine (-NH-) and a benzotriazole ultraviolet absorption segment; the improvement of the light fastness of the dye is not obvious and can only reach 6 grades, which is lower than the light fastness (7 grades) grade of the dye I, and the connection mode between the ultraviolet absorption segment and the dye can influence the light fastness of the dye.

The color fastness to water, dry rubbing, wet rubbing, sublimation and photooxidation of the dye are slightly inferior to that of the dye I, and are about half-level lower than that of the dye I.

Comparative examples 3,

Compared with the dye II, the dye II introduces benzotriazole ultraviolet absorption segments containing tert-butyl in the ortho-position of hydroxyl into indigo dye, the improvement of the light fastness of the dye is also not obvious and can only reach 6 grades, which is lower than the first-grade half of the light fastness (7-8 grades) of the dye II, and the improvement shows that the alkyl type in the ultraviolet absorption segments can also influence the light fastness of the dye.

The color fastness to water, dry rubbing, wet rubbing, sublimation and photo-oxidation of the dye are slightly inferior to those of the dye II; about half-order lower than the dye II of the present invention.

Finally, it is also noted that the above-mentioned lists merely illustrate a few specific embodiments of the invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.

Claims (5)

1. The sun-proof blue acid dye is characterized by having the following structural general formula:

r is H or sec-butyl.

2. The light fast blue acid dye according to claim 1, characterized by the structural formula of any one of:

3. the process for preparing a light fast blue acid dye according to claim 1 or 2, characterized by comprising the steps of:

1) grinding the indigo dye and dispersing the indigo dye in water to obtain a dye suspension;

dissolving a chlorine-containing water-soluble benzotriazole ultraviolet absorbent in water to obtain an ultraviolet absorbent solution;

mixing the dye suspension, the ultraviolet absorbent solution and potassium carbonate, and then carrying out heat preservation reaction at 110 +/-10 ℃ for 12-16 hours to obtain a reaction product solution;

the indigo dye: chlorine-containing water-soluble benzotriazole ultraviolet absorbers: potassium carbonate in a molar ratio of 1:2: 2;

the indigo dye is:

the chlorine-containing water-soluble benzotriazole ultraviolet absorbent is

Or is that

2) And carrying out post-treatment on the reaction product solution obtained in the step 1) to obtain the sun-proof blue acid dye.

4. The method for preparing the sun-fast blue acid dye according to claim 3, wherein the step 2) is as follows: adding sodium chloride into the reaction product solution obtained in the step 1) until the sodium chloride is saturated to generate a precipitate; removing salt in the precipitate by adopting a DMF-ether method, and drying to obtain the sun-proof blue acid dye.

5. The method for preparing a light fast blue acid dye according to claim 3 or 4, wherein in the step 1):

adding 20 plus or minus 5mL of water into 0.01mol of indigo dye to obtain dye suspension;

40 plus or minus 10ml of water is matched with 0.02mol of chlorine-containing water-soluble benzotriazole ultraviolet absorbent to obtain ultraviolet absorbent solution.