JPH11148025A - Concentrated solution of optical whitening dye - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a concentrated solution of optial whitening dye capable of preventing worsening of working environment by dusting of fine particles, enhancing solubility to allow its usage at a high concentration and automating by including a specific disulfonic acid obtained by acid precipitation or an alkali salt thereof and an alkanol amine. SOLUTION: This solution is obtained by including (A) 4,4'-bis[2-(4- sulfoanilino)-4-duethanolamino-1,3,5-triazinyl-6-amino]stilbene-2,2'-d isulfonic acid shown by the formula (M is H or an alkali metal) obtained by acid precipitation or an alkali salt thereof and (B) an alkanol amine (e.g. triethanolamine). The solution contains components A and B, preferably, at 10-50 wt.%, as a free acid, and 5-25 wt.%, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a concentrated solution of a fluorescent white dye. More specifically, obtained by acid precipitation
The present invention relates to a concentrated solution of 4'-bis [2- (4-sulfoanilino) -4-diethanolamino-1,3,5-triazinyl-6-amino] stilbene-2,2'-disulfonic acid or an alkali metal salt thereof.

[0002]

2. Description of the Related Art 4,4'-Bis [2- (4-sulfoanilino) -4-diethanolamino-1,3,5-triazinyl-6-amino] stilbene-2,2'-disulfonic acid has the following formula (1)

[0003]

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[0004] An excellent fluorescent white dye represented by the formula (1), wherein M represents H or an alkali metal, and is usually supplied to the market in powder form. Used as an aqueous solution. However, as always with the handling of powders, their operation involves undesired disadvantages in operation, such as scattering of the powders and the time required for dissolution.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to reduce the working environment due to scattering of powder, to enhance solubility, to enable use at a high concentration, and to provide automated equipment. The object is to provide a concentrated solution of the compound of formula (1) which can be easily handled.

[0006]

The present inventors have conducted intensive studies to obtain a stable and concentrated solution of the compound of the formula (1), and have reached the present invention. That is, the present invention relates to (1) 4,4'-bis [2- (4-sulfoanilino) -4-diethanolamino-1,3,5-triazinyl-6-amino] stilbene-2,2'-disulfone obtained by acid precipitation. Provided is a concentrated solution of a fluorescent white dye, characterized by containing an acid or an alkali metal salt thereof and an alkanolamino.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail. In the present invention, the compound of the formula (1) can be used, for example, in JP-B-33-76.
38. The Na salt of the compound of the formula (1) is acid precipitated with a mineral acid to obtain a compound of the formula (1) wherein M is hydrogen, or this is further treated with an alkali hydroxide in water to obtain a compound of the formula (1) In which M is an alkali metal. It is preferable to add hydrochloric acid to the reaction solution, for example, squeeze out a solution obtained by acid precipitation at pH 2 to 3 with a pressing press, and to reduce the concentration of chloride ions contained in the obtained press cake to 1.5 to 3%.

In the present invention, it is preferable to use one in which M is H or Li. The proportion of the compound of the formula (1) in the concentrated solution is usually 10 to 50% as a free acid,
Preferably it is 15-35% (weight ratio).

In the present invention, examples of the alkanolamine include monoethanolamine, diethanolamine, triethanolamine, triisopropanolamine, methyldiethanolamine, and the like. Particularly, use of triethanolamine and triisopropanolamine is preferred. The preferred content of alkanolamine in the concentrated solution of the present invention is 5 to 25%, more preferably 8 to 1%.
6% (weight ratio).

In the concentrated solution of the present invention, in addition to the alkanolamine, if necessary, a conventional solubilizer such as glycols and urea, a fungicide, and the like can be added. Examples of the glycols include ethylene glycol, diethylene glycol, polyethylene glycol, and the like.
These are added to the concentrated solution as needed at 1 to 10% (weight ratio). Also, urea is added to the concentrated solution in a range of 1 to 15% (weight ratio) as necessary. Water is usually added so as to have a content of 40 to 70% (weight ratio).

The concentrated solution of the present invention can be obtained by simply mixing and dissolving the above-mentioned various drugs in water. After mixing and dissolving, if necessary, it is preferable to remove insoluble substances such as contaminants by filtration. The thus obtained concentrated solution of the present invention is free from dust and, of course, does not precipitate or decompose the compound represented by the formula (1) (fluorescent white dye) even after long-term storage. . Further, freezing in low-temperature storage and evaporation of water in high-temperature storage are unlikely to occur.

[0011]

The present invention will be described below by way of examples. In the examples, parts mean parts by weight.

Example 1 Hydrochloric acid was added to a reaction solution of 4,4'-bis [2- (4-sulfoanilino) -4-diethanolamino-1,3,5-triazinyl-61-amino] stilbene-2,2'-disulfonate. In addition, the solution acidified at pH 2-3 was filtered (squeezed with a pressing press), and 50 parts of the obtained wet cake (25 parts of dye, 25 parts of water) was added to 40 parts of triethanolamine.
Add 3 parts of polyethylene glycol and 35 parts of water and add
After dissolving the wet cake by stirring for ~ 2 hours, insoluble residues are removed by screening. The concentrated solution of the present invention thus obtained is extremely stable,
It survived long-term storage at 10 ° C to 60 ° C (half a year or more) and maintained a transparent solution state. Also, no deterioration in dyeing properties and physical properties was observed. In addition, when the chlorine ion concentration of this wet cake was measured, it was 2%.

Example 2 A compound of the formula (1) (M
To 50 parts (30 parts of dye, 20 parts of water), 10 parts of triethanolamine, 1 part of diethylene glycol, 8 parts of urea, and 20 parts of water are added, and the mixture is stirred for 1 to 2 hours. After dissolving and screening, 11 parts of water was added for concentration adjustment to obtain a concentrated solution of the present invention having a total volume of 100 parts. This showed the same excellent properties as the target product of Example 1.

Example 3 4,4′-bis [2-
(4-Sulfoanilino) -4-diethanolamino-1,3,5-triazinyl-6-amino] stilbene-2,2′-disulfonic acid (50 parts) (dye content 30 parts, water 20 parts), triethanolamine 14 parts, and water After adding 30 parts and stirring for 1 to 2 hours to dissolve, an insoluble residue is removed by screening. Finally, 6 parts of water was added for concentration adjustment to obtain a concentrated solution of the present invention having a total liquid volume of 100 parts. The concentrated solution thus obtained was extremely stable, withstands long-term storage at -10 ° C to 60 ° C (half a year or more), and kept a clear solution. Also dyeability,
No deterioration in physical properties was observed.

Example 4 The compound (M) of the formula (1) obtained in the same manner as in Example 1 was obtained.
Is H) 50 parts (dye content 25 parts, water 25
), 10 parts of triisopropanolamine, 2 parts of diethylene glycol, and 30 parts of water were added, and the mixture was stirred for 1 to 2 hours to dissolve. After screening, 8 parts of water was added for concentration adjustment. And the total liquid volume is 100
Part of the concentrated solution of the invention was obtained. This showed the same excellent properties as in Example 1.

Example 5 A concentrated solution of the present invention was prepared in the same manner as in Example 4 also for a compound of the formula (1) obtained by treating in the same manner as in Example 1, wherein M is a mixture of H and Li. Obtained.

[0017]

EFFECT OF THE INVENTION 4,4'-Bis [2- (4-sulfoanilino) -14-diethanolamino-1,3,5-triazinyl-61-amino] stilbene-2,21-disulfonic acid or its alkali metal salt can be stored for a long time. A stable concentrated solution was obtained.

Claims (1)

[Claims] (1) 4,4-bis [2- (4-sulfoanilino) -14-diethanolamino) obtained by acid precipitation
1. A concentrated solution of a fluorescent white dye, comprising [1,3,5-triazinyl-6-amino] stilbene-2,2'disulfonic acid or an alkali metal salt thereof and an alkanolamine.