JP2000273348A - Dye dispersant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye dispersant very excellent in high temperature dyeing properties. SOLUTION: This dye dispersant is obtained by reacting an aqueous solution of a purified ligninsulfonic acid salt with an aminophenol and formaldehyde under aqueous conditions. Desirably, the wt. ratio of the aqueous solution of the purified ligninsulfonic acid salt to the aminophenol, in terms of solid contents, is 100:10 to 100:40, the molar ratio of the aminophenol to formaldehyde is 1:1.0 to 1:1.3 and the aminophenol is p-aminophenol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dye dispersant, and more particularly to a dye dispersant having excellent performance in high-temperature dyeability.

[0002]

2. Description of the Related Art Disperse dyes have conventionally been used for dyeing polyester fibers and the like. This is because the dye precursor itself of the disperse dye itself is insoluble or hardly soluble in water, so that it can be stably dispersed in water using a dispersant. As the dispersant in this case, purified lignin sulfonic acid or naphthalene sulfonic acid formaldehyde condensate which has been mainly subjected to a partial desulfonation reaction has been used.

[0003]

The sulphite pulp effluent obtained by purifying only the lignin content by means such as ultrafiltration is generally called a purified lignin sulfonate. For disperse dye applications, purified ligninsulfonate obtained by subjecting this purified ligninsulfonate to a partial desulfonation reaction under high temperature and alkaline conditions is used. Examples of commercially available products include Pearl Rex DP manufactured by Nippon Paper Industries Co., Ltd.

The characteristics of the purified lignin sulfonate subjected to the partial desulfonation reaction are such that the dyeing property (high-temperature dyeing property) at the time of high-temperature dyeing such as dyeing of polyester fiber and the like is different from that of naphthalenesulfonic acid formaldehyde condensate. Is superior to the above dispersant.

However, recently, from the viewpoint of increasing the concentration of the disperse dye (increase the proportion of the dye base in the disperse dye and reduce the proportion of the dispersant), a dispersant having excellent high-temperature dyeability even when used in smaller amounts. Demand for agents is increasing.

On the other hand, purified ligninsulfonate has significantly poor high-temperature dyeability as compared with purified ligninsulfonate subjected to a partial desulfonation reaction.

As a result of various studies, the present inventors have conducted a partial desulfonation reaction using a purified lignin sulfonate aqueous solution, a reaction product obtained by reacting an aminophenol and formaldehyde in aqueous solution as a dispersant. It has been found that it has very good high-temperature dyeability as compared with the purified lignin sulfonate.

Accordingly, an object of the present invention is to provide a dye dispersant having excellent high-temperature dyeability.

[0009]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a high-temperature dyeing property can be greatly improved by using a purified lignin sulfonate aqueous solution, a dye dispersant obtained by reacting an aminophenol and formaldehyde in an aqueous solution. I found something that could be improved.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the weight ratio of purified lignin sulfonate aqueous solution to aminophenols (in terms of solid content) is 100: 10 to 100: 40, and the molar ratio of aminophenols to formaldehyde is 1: 1.0. Preferably it is あ る 1: 1.3. In the weight ratio of the purified lignin sulfonate aqueous solution to the aminophenols,
When the ratio is 0:10 or less, the effect of improving the high-temperature dispersibility is not so much seen, and when the ratio is 100: 40 or more, the effect of improving the high-temperature dispersibility reaches a plateau, resulting in a disadvantage in cost.

In the molar ratio of aminophenols to formaldehyde, the molar ratio of formaldehyde is
When the ratio is 1: 1.0 or less, it is not preferable because the residual monomer of aminophenol is generated. When the molar ratio is 1: 1.3 or more, there is a problem that the condensation reaction proceeds due to excess formaldehyde and the reaction product becomes highly viscous.

The aminophenols used in the present invention are desirably used in the reaction as an aqueous solution dissolved with an equimolar amount of an alkali (eg, caustic soda). If the amount of the alkali is too large, the pH of the dye dispersant increases, which is not preferable. If the amount of the alkali is too small, aminophenols do not dissolve.

The aminophenols used in the present invention include p-aminophenol, m-aminophenol and o-aminophenol.
-Aminophenol and the like, and p-aminophenol is most preferable because of its excellent performance and inexpensiveness.

As the aqueous solution of the purified lignin sulfonate used in the present invention, one obtained by purifying the lignin content of a softwood sulphite pulp effluent by means such as ultrafiltration is usually used. A methoxyl (OCH ₃ ) group is usually used as an index of the degree of purification of the lignin content. The methoxyl group content of the aqueous solution of the purified lignin sulfonate used in the present invention is about 9 to 12% (based on solid content). Are preferred. The salt form is usually an alkali metal salt such as sodium. Use of a purified lignin sulfonate which has been subjected to a partial desulfonation reaction under high temperature and alkaline conditions is more effective in enhancing high temperature dyeing performance. The degree of sulfonation of the purified lignin sulfonate subjected to the partial desulfonation reaction is 2.0 to 6.0 in terms of the sulfur content of the sulfone group.
% (Based on solid content).

After completion of the reaction, the reaction product of the present invention is commercialized in a liquid state or in a powdered state by a spray dryer or the like according to the user's request.

The form of the salt of the reaction product of the present invention is usually an alkali metal salt such as sodium.

The reaction is further carried out under aqueous conditions (solids concentration: 20 to 40%) under normal pressure or under pressure at a temperature of 50 ° C. to 140 ° C., usually for 4 to 50 hours.
In addition, it is desirable that dropping of formaldehyde is performed in 1 to 2 hours.

The reactant of the present invention does not cause any problem when used in combination with a conventional dye dispersant such as a purified ligninsulfonic acid or a naphthalenesulfonic acid formaldehyde condensate which has been subjected to a partial desulfonation reaction.

[0019]

When the reactant of the present invention is used, a dye dispersant having excellent high-temperature dyeability can be obtained. The reason why the dye dispersant of the present invention was able to improve the high-temperature dyeing property as compared with the purified lignin sulfonate subjected to the conventional partial desulfonation reaction is as follows. By adding the skeleton via an amino group,
It is presumed that the adsorptivity to the dye precursor increased, which greatly contributed to the improvement of high-temperature dyeability.

[0020]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

Reaction Example 1 Purified lignin sulfonic acid sodium salt aqueous solution subjected to a partial desulfonation reaction (pearl rex DP, manufactured by Nippon Paper Industries Co., Ltd., with a methoxyl group content of 9.8% (based on solid content) and a solid content concentration of 30%) Dissolution) and p-aminophenol aqueous solution (p-
An aminophenol powder was dissolved in an equimolar sodium hydroxide solution at a solid content of 20%) and mixed at a weight ratio (solid content ratio) of 100: 20. This was heated to 90 ° C. with stirring, and formaldehyde (a 37% aqueous formaldehyde solution) was added dropwise over 1 hour (a molar ratio of p-aminophenol to formaldehyde was 1: 1.05), and then reacted at 90 ° C. for 19 hours. The reaction product of Reaction Example 1 was obtained.

Reaction Example 2 Purified ligninsulfonic acid sodium salt aqueous solution (methoxyl group content 11.8% (based on solid content), solid content concentration 25%) and p
-Aminophenol aqueous solution (solids concentration 25% in which p-aminophenol powder is dissolved with equimolar sodium hydroxide)
Was mixed at a weight ratio (solid content ratio) of purified ligninsulfonic acid sodium salt and p-aminophenol of 100: 35. This was heated to 80 ° C. with stirring, and formaldehyde (37% aqueous formaldehyde solution) was added dropwise over 2 hours (in a molar ratio of p-aminophenol and formaldehyde).
1: 1.10) and then reacted at 120 ° C. for 12 hours to obtain a reaction product of Reaction Example 2.

Reaction Example 3 Purified ligninsulfonic acid sodium salt aqueous solution (methoxyl group content 10.5% (based on solid content), solid content concentration 35%) and m
-Aminophenol aqueous solution (solid concentration of 15% in which m-aminophenol powder is dissolved with equimolar sodium hydroxide)
Was mixed at a weight ratio (solid content ratio) of purified ligninsulfonic acid sodium salt and m-aminophenol of 100: 20. This was heated to 70 ° C. with stirring, and formaldehyde (a 37% aqueous formaldehyde solution) was added dropwise over 1 hour (at a molar ratio of m-aminophenol and formaldehyde).
1: 1.20) and then reacted at 70 ° C. for 40 hours to obtain a reaction product of Reaction Example 3.

Reaction Example 4 Purified ligninsulfonic acid sodium salt aqueous solution (methoxyl group content 11.0% (based on solid content), solid content concentration 25%) and o
-Aminophenol aqueous solution (solid concentration 25% dissolved o-aminophenol powder with equimolar caustic soda)
Was mixed at a weight ratio (solid content ratio) of purified ligninsulfonic acid sodium salt and o-aminophenol of 100: 8. This was heated to 70 ° C. with stirring, and formaldehyde (a 37% aqueous formaldehyde solution) was added dropwise over 1 hour (at a molar ratio of o-aminophenol and formaldehyde).
1: 0.9) and then reacted at 75 ° C. for 8 hours to obtain a reaction product of Reaction Example 4.

Reaction Example 5 Purified ligninsulfonic acid sodium salt aqueous solution (methoxyl group content 11.2% (based on solid content), solid content concentration 30%) and m
-Aminophenol aqueous solution (solid concentration of 15% in which m-aminophenol powder is dissolved with equimolar sodium hydroxide)
Was mixed at a weight ratio (solid content ratio) of purified ligninsulfonic acid sodium salt and m-aminophenol of 100: 50. This was heated to 90 ° C. with stirring, and formaldehyde (37% aqueous formaldehyde solution) was added dropwise over 1 hour (in a molar ratio between m-aminophenol and formaldehyde).
1: 1.5), and then reacted at 95 ° C. for 30 hours to obtain a reaction product of Reaction Example 5.

Example (High-Temperature Dyeing Test) A naphthalenesulfonic acid formaldehyde condensate and a dye precursor (CIDisperse Red 60) were mixed at a solid content weight ratio of 1: 2.5.
Water is added to the mixture, and after stirring, the dye base is atomized with a juicer mixer and a sand mill (using glass beads) to obtain a dye crushing solution (solid content: about 20%). Next, the dye crushing solution (solid content 0.8 g) and water are added to various dispersant solutions (solid content 0.5 g), and the pH is adjusted to 5.0 with acetic acid. . Next, a dyeing holder in which 10 g of a polyester jersey cloth was wound around an inner cylinder was set in a dyeing pot, and dyed with a color pet dyeing machine (manufactured by Nippon Dyeing Machine Co., Ltd.) (13).
0 ° C, 10 minutes). Cool quickly after dyeing, immediately take out the polyester jersey cloth, wash with water and air dry. After air drying,
The polyester jersey cloth was taken out, and some of the dye aggregates adhering to the fibers were visually evaluated on a scale of 10 as follows.

The results are shown in Table 1. In the table, rank 10 was the best evaluation in which no adhesion of aggregates was observed, and rank 1
Indicates that the aggregates are markedly attached in the worst evaluation.

The dispersants used in the tests were as described in Reaction Examples 1 to 5
And purified lignin sulfonic acid sodium salt subjected to a partial desulfonation reaction as a control (using Pearlex DP manufactured by Nippon Paper Industries Co., Ltd., methoxyl group content: 9.8%), purified lignin sulfonic acid sodium salt (Methoxyl group content 11.0%), naphthalenesulfonic acid formaldehyde condensate (Vaniol HD manufactured by Nippon Paper Industries Co., Ltd.)
-200).

[0029]

[Table 1] Table 1

From the results shown in Table 1, the dye dispersant of the present invention shows that
It turns out that it is very excellent in high temperature dyeability.

[0031]

By using the reactant of the present invention, a dye dispersant having very good high-temperature dyeing properties can be obtained.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshihiro Sugiwaki 2-8-1 Iida-cho, Iwakuni-shi, Yamaguchi Prefecture Nippon Paper Industries Co., Ltd. Kaseihin R & D Laboratory (72) Inventor Masanobu Kawamura 2-8 Iida-cho, Iwakuni-shi, Yamaguchi Prefecture -1 F-term in Nippon Paper Industries Co., Ltd. Chemical Research Laboratory (reference) 4H057 AA01 BA08 CA16 CB03 CB10 CC02 DA01 DA17 GA07 GA21 GA25

Claims (4)

[Claims] 1. A dye dispersant obtained by reacting an aqueous solution of a purified lignin sulfonate, an aminophenol and formaldehyde under aqueous conditions. 2. The weight ratio of the aqueous solution of purified lignin sulfonic acid salt to aminophenols (in terms of solid content) is 100: 10 to 10:
The dye dispersant according to claim 1, wherein the molar ratio of the aminophenols to formaldehyde is from 1: 1.0 to 1: 1.3. 3. The dye dispersant according to claim 1, wherein the aminophenol is p-aminophenol. 4. The dye dispersant according to claim 1, wherein an aqueous solution of purified lignin sulfonate having undergone a partial desulfonation reaction is used.