WO2006004056A1

WO2006004056A1 - Process for producing thick aqueous solution of azo and/or azoxystilbene dye

Info

Publication number: WO2006004056A1
Application number: PCT/JP2005/012235
Authority: WO
Inventors: Fumitaka Satou; Takao Aizawa; Hiroshi Sugiyama
Original assignee: Nippon Kayaku Kabushiki Kaisha; Kabushiki Kaisha Nippon Kayaku Tokyo
Priority date: 2004-07-01
Filing date: 2005-07-01
Publication date: 2006-01-12
Also published as: JP2007262105A

Abstract

A process for efficiently producing a thick aqueous solution of a yellow azo- and/or azoxystilbene dye obtained by the self-condensation of a 4-nitrotoluene-2-sulfonic acid in the presence of an alkali metal hydroxide. The process, which is for producing a thick aqueous solution, comprises converting a sparingly water-soluble alkali metal salt of the azo and/or azoxystilbene dye into an oleophilic ammonium salt (primary amine conversion) and then converting it into an alkanolammonium salt (secondary amine conversion), wherein the primary amine conversion is conducted either in a system comprising a C12-40 trialkylamine, diethylbenzene, and water or in a system comprising a C12-40 trialkylamine and water and the secondary amine conversion is conducted by adding a C2-4 alkanolamine to a phase of the oleophilic ammonium salt. Thus, a thick aqueous solution of the dye is produced.

Description

Process for producing concentrated aqueous solutions of azo and Z or azoxystilbene dyes

[0001] The present invention relates to a method for producing a concentrated aqueous solution of a dye. More specifically, a concentrated aqueous solution excellent in storage stability of yellow azo and Z or azoxystilbene dyes obtained by self-condensation of 4-trotoluene 2-sulfonic acid in the presence of alkali metal hydroxide. Relates to the manufacturing method.

Background art

[0002] Azo and Z or azoxystilbene dyes obtained by condensing 4-trotoluene 2-sulfonic acid in the presence of an alkali metal hydroxide are particularly useful for coloring paper. It is supposed that it has a structural formula represented by the formula (1). (Yu Hosoda, “Theory 'Manufacturing, Dye Chemistry”, published by Gihodo in 1962)

[0003] [Chemical 1]

[0004] 4-azotoluene 2-sulfonic acid obtained by self-condensation in the presence of an alkali metal hydroxide, azo and Z or azoxystilbene dyes (hereinafter these dyes are simply combined to form a stilbene dye) Is a yellow dye, and as mentioned above, it is frequently used as a dye for pulp and paper. When the dye is used for dyeing pulp, paper, etc., it is handled as a concentrated aqueous solution in the factory, taking into account the convenience of handling and the power transport efficiency. However, the stilbene dye is relatively insoluble in water, and the solubility of the alkali metal salt of the stilbene dye in water is estimated to be about lgZlOOml. Therefore, a concentrated aqueous solution is obtained. Various ideas have been proposed for this purpose. For example, a method of forming an alkanolamine salt of a stilbene dye is carried out, in particular a two-step amine conversion that converts to a water-insoluble ammonia salt and then to a water-soluble ammonia salt. The law has been proposed as an effective method. Specifically, for example, in Patent Document 1, an alkali metal salt of a stilbene dye is a two-phase system of nitrobenzene Z water, and firstly a lipophilic ammonia is used using di- or trialkylamine having 12 to 40 carbon atoms. Convert to um salt and form a water-soluble alkanol ammonium salt using mono-, di- or trialkanolamine in which 2 to 4 carbon atoms are present in the alkyl group. Thus, a method for obtaining a concentrated aqueous solution of a stilbene dye has been proposed. In Patent Document 2, an alkali metal salt of a stilbene dye is a two-phase system of methyl isobutyl ketone Z water, and a lipophilic ammonia is first used using a trialkylamine having 12 to 40 carbon atoms. The stilbene dye is converted to a salt and then formed into a water-soluble alkanol ammonium salt using a mono-, di- or trialkanolamine having 2 to 4 carbon atoms of an alkenol group. A method of obtaining a concentrated water solution of is proposed.

[0005] Patent Document 1: Japanese Patent Publication No. 6-99644 (Page 14)

Patent Document 2: Special Table 2003-501510 (Page 8-15)

Disclosure of the invention

Problems to be solved by the invention

[0006] As a method for obtaining concentrated aqueous solutions of azo and Z or azoxystilbene dyes (stilbene dyes) obtained by self-condensation of 4-trotoluene 2-sulfonic acid, there are various disadvantages in the above-mentioned conventional methods. There is. That is, in the method described in Patent Document 1, an alkali metal salt of a stilbene dye is first converted into a poorly water-soluble ammonium salt, then extracted with trobenzene, and then converted into a water-soluble alkanol ammonium salt. The power of the transformation and the extraction of the dye into the organic phase. In this method, the separation of the nitrobenzene phase from the aqueous phase containing the water-soluble alkanol ammonium salt of the dye takes a long time. There is a disadvantage that it takes. Further, even in the method described in Patent Document 2, phase separation between a water-soluble alcoholic ammonium salt and methylisobutyl ketone used as a medium is not sufficient, and therefore, a part of methylisobutylketone is an aqueous phase. To remain in the ammonium salt In addition, there is a difficulty in that it must be removed by azeotropic distillation, for example.

[0007] An object of the present invention is to develop a method for efficiently producing a concentrated aqueous solution of a stilbene dye that eliminates the above-mentioned drawbacks in a conventionally known method in obtaining a concentrated aqueous solution of a stilbene dye.

Means for solving the problem

[0008] As a result of diligent research to solve the above problems, the present inventors have found that when producing a concentrated aqueous solution having excellent storage stability of a stilbene dye, a hardly soluble alkali metal salt is hardly soluble in water and an amorphous salt. To be converted into water-soluble alkanol ammonium salt, and then to serve as a medium for the poorly water-soluble amine to form Jetylbenzene Z water or a large amount of poorly water-soluble ammonia salt. Thus, the inventors have found that the above problems can be solved, and have completed the present invention.

[0009] That is, the present invention provides

(1) A poorly water-soluble alkali metal salt of a yellow azo and / or azoxystilbene dye obtained by self-condensation of 4-trotoluene 2-sulfonic acid in the presence of an alkali metal hydroxide is converted into a lipophilic ammonia. A method for producing a concentrated aqueous solution excellent in storage stability of the dye by converting into a -um salt (primary amine conversion) and then converting into an alkanol-am salt (secondary amine conversion); The primary amine conversion is carried out by using at least one trialkylamine having 12 to 40 carbon atoms and a system of jetylbenzene and water or at least one trialkylamine having 12 to 40 carbon atoms. The secondary amine conversion is carried out using a system of amine and water, and the trialkylamine and jetylbenzene phase obtained by the primary amine conversion or the trialkylamine phase is used. Mono one carbon atom is 2-4, preparation of concentrated aqueous solutions of said dye to feature that performed by 添Ka 卩 di one or Toriarukano one Ruamin,

(2) The production method according to (1), wherein the trialkylamine in the secondary amine conversion is a trialkylamine having 12 to 25 carbon atoms,

(3) The production method according to (2), wherein the trialkylamine having 12 to 25 carbon atoms is tri-n-octylamine.

(4) Primary amine conversion is carried out in a system with a large excess of tri-n-octylamine and water in excess of this mole (1 ) Manufacturing method described in the

(5) A mono-, di- or trialkanolamine having 2 to 4 carbon atoms in the alkanol group is a di- or trialkanolamine having 2 to 4 carbon atoms in the alkanol group. The manufacturing method according to any one of (1) to (4),

(6) The production method according to (5), wherein the dialkanolamine having 2 to 4 carbon atoms in the alkanol group is diethanolamine;

(7) The production method according to any one of (1) to (6), wherein the secondary amine conversion is performed in a tri-n-octylamine and water system, and the secondary amine conversion is performed by adding diethanolamine.

(8) The production method according to any one of (1) to (7), wherein primary amine conversion is carried out using the dye synthesis reaction solution as it is and under acidic conditions.

About.

The invention's effect

[0010] The production method of the present invention is excellent in separability between an aqueous phase containing a water-soluble alkanol ammonium salt of a stilbene dye and a jetylbenzene phase used for conversion to the ammonium salt. Efficient production of concentrated aqueous solutions of stilbene dyes without the need for troublesome processes such as azeotropic distillation to remove jetylbenzene in water (concentrated aqueous solutions) containing water-soluble alkanol ammonium salts of dyes It becomes possible to do. BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The present invention will be described in detail.

[0012] First, the stilbene dye to be used in the production method of the present invention can be obtained by the method described in the above-mentioned document (Toyo Hosoda, "Theory" Production Dye Chemistry, published by Gihodo, 1962), for example, as follows. Can be manufactured. That is, 4-trotoluene-2-sulfonic acid is added to an aqueous solution of an alkali metal hydroxide such as potassium hydroxide, preferably sodium hydroxide. The amount of alkali metal hydroxide can vary within a wide range, but crude 4-trotoluene 2-sulfonic acid may have sulfuric acid attached to it, so neutralize the sulfuric acid. Even so, it is preferably used in a molar excess of 2 to 4 times based on 4-trotoluene 2-sulfonic acid so that the amount is sufficient. The amount of water is usually about 5 times the weight ratio of 4-trotoluene 2-sulfonic acid. For example, this condensation reaction For example, at pH 11 to 13 and at a temperature of 50 to 80 ° C for 5 to 8 hours. The end point of the condensation reaction is confirmed by checking the residual amount of 4-trotoluene 2-sulfonic acid by liquid chromatography. When the condensation reaction is completed, it may be obtained by filtration to obtain an alkali metal salt of a stilbene dye. However, the reaction solution is used as it is as a raw material for carrying out the production method of the present invention without separating the alkali metal salt of the stilbene dye. It is preferable to use as

[0013] (First-order amine transformation)

Water is added to the separated alkali metal salt of the stilbene dye or the alkali metal salt of the stilbene dye, and an inorganic strong acid, preferably sulfuric acid, is further added and stirred sufficiently to obtain an aqueous suspension or aqueous solution. At this time, the pH of the solution should be 3 to 5, preferably around 4, and the amount of water should be 1 to 5 times, preferably 2 to 4 times by weight with respect to the alkali metal salt of the stilbene dye. Adjust the addition amount of strong acid and water respectively.

Next, trialkylamine having 12 to 40 carbon atoms and jetylbenzene are encapsulated in the aqueous suspension or aqueous solution. The amount of addition force of jetylbenzene is usually 20 to 27 parts by weight, preferably 22 to 25 parts by weight, per 100 parts by weight of the aqueous suspension or aqueous solution. Also, the loading of trialkylamines having 12 to 40 carbon atoms is 100 to 110% of the number of moles required to completely convert the sulfonic acid group on the stilbene dye to an ammonium salt. Mol, preferably 100 to 105% mol. By adjusting the pH to 3-5, preferably around 4, by stirring sulfuric acid, the mixture is stirred for 30 minutes to 2 hours at a temperature of 60-80 ° C to give the corresponding lipophilic ammonia. After complete conversion to salt, it was allowed to stand and contained an inorganic salt with a stilbene dye lipophilic ammonia salt and an excess of a trialkylamine having 12 to 40 carbon atoms and a trialkylamine. Separate into aqueous phase. After removing the lower layer aqueous phase, the inorganic salt is sufficiently removed by washing the jetylbenzene phase preferably once or twice with hot water of 60 to 70 ° C. Specific examples of the trialkylamine having 12 to 40 carbon atoms used herein include tri (carbon number 4 to 13) alkyl such as tributylamine, tri-n-octylamine and triisooctylamine. An amine is mentioned, but trialkylamine having 12 to 25 carbon atoms is preferred, and tri-n-octylamine is particularly preferred. In the tree n-octylamine In addition, it may contain a similar alkylamine such as dioctyl monon-de-lamine. In the amine conversion, a stilbene dye can be used in the same manner as in the case of using jetylbenzene by using a large excess of trialkylamine having 12 to 40 carbon atoms without using any jetylbenzene. It is possible to obtain a liquid comprising an amine phase and an aqueous phase containing a lipophilic ammonia salt. In this case, the same trialkylamine having 12 to 40 carbon atoms can be used as described above, which is 105% of the number of moles required to convert all the alkali metal salt to the trialkylamine salt. Above, preferably 120-200% trialkylamine is used. In the same manner as described above, the amine solution containing the lipophilic ammonia salt of the stilbene dye is washed with warm water or water to remove inorganic salts contained in the amine solution.

[0015] (secondary amine transformation)

Next, a benzene solution containing a lipophilic ammonium salt of a stilbene dye obtained as described above or a trialkylamine solution having 12 to 40 carbon atoms, followed by 2 to 4 carbon atoms of an alkanol group. Individual mono-, di- or trialkanolamines are added and stirred and mixed in a temperature range of 60-80 ° C for 1-3 hours. The lipophilic ammonia salt of the stilbene dye is converted to a hydrophilic alkanol ammonium salt, and the jetyl benzene phase or the trialkylamine phase having 12 to 40 carbon atoms is separated and transferred. By leaving it stationary, it is separated into a jetylbenzene phase or a trialkylamine phase having 12 to 40 carbon atoms and an aqueous phase, and then a jetylbenzene phase or a trialkylamine having 12 to 40 carbon atoms. By removing the alkylamine phase, a concentrated aqueous solution containing the stilbene dye alminol ammonium salt is obtained. Here, specific examples of mono-, di- or trialkanolamines having 2 to 4 carbon atoms of the alkanol group which can be used include diisopropanolamine, trihetanolamine, triisopropanolamine, diethanolamine. In the present invention, dialkanoamines such as diethanolamine and diisopropanolamine are preferred, and diethanolamine is particularly preferred. Better!/,.

[0016] The amount of the alkanolamine is 110% or more of the number of moles required for converting the alkyl ammonium salt of the stilbene dye into its alkyl ammonium salt, preferably 120 to Use 200% alkanolamine.

[0017] After the secondary amine conversion, the aqueous phase of the alkanol ammonium salt of the stilbene dye forming the lower layer and the trialkylamine phase of the lipophilic ammonia salt of the stilbene dye forming the upper layer are separated. After the lower aqueous phase is separated, the trialkylamine solution is added to the upper trialkylamine solution as necessary, and then the alkali metal salt of the stilbene dye is prepared and the following production can be carried out.

[0018] By using water-insoluble jetylbenzene in the organic phase, during the formation of the lipophilic ammonium salt and during the formation of the hydrophilic alkanol ammonium salt, the aqueous phase and the organic phase Since the good phase separation is performed promptly, it is easy to remove the inorganic salt in the concentrated aqueous solution, and no steps other than phase separation, removal, and washing are required. Usually only one piece is required, and the manufacturing process is greatly simplified. The concentrated aqueous solution of stilbene dye obtained by the production method of the present invention carried out by such a method usually contains 15 to 25% by weight of stilbene dye, and 20% by weight under preferable conditions.

[0019] In the production method of the present invention, the dialkylbenzene containing trialkylamine can be used again after adding the amount of trialkylamine lost to the aqueous phase, if necessary, without purification. . In the production method of the present invention, if necessary, it can be purified by adding a filtration step and an activated carbon treatment-filtration step. In particular, when there is a concern that trialkylamine having 12 to 40 carbon atoms and jetylbenzene remain in a concentrated aqueous solution, it is preferable to perform an activated carbon treatment and filtration.

[0020] The concentrated aqueous solution of the stilbene dye obtained by the production method of the present invention is suitable for coloring various substrates, and particularly suitable for dyeing (coloring) size or non-size pulp paper. As a method for dyeing, a method of adding a stilbene dye according to the present invention to a size press solution in a size press step after paper making, in addition to a known pulp internal addition method, can be employed. When the paper is dyed (colored) using the concentrated aqueous solution obtained by the production method of the present invention, it exhibits high directness and build-up property, and at the same time, the color of the waste liquid is excellent. The concentrated aqueous solution obtained by the production method of the present invention exhibits high dyeing suitability for pulp fibers and paper, as well as cellulose fibers and regenerated cellulose fibers.

Example [0021] The present invention will be described in more detail with reference to the following examples. In an embodiment, parts are parts by weight.

,% Means% by weight.

[0022] Example 1

Look at the glass flask with 800 parts of water, and then add 480 parts of 48% aqueous sodium hydroxide so that the temperature does not exceed 50 ° C. It is then heated to 50 ° C. and then 406 parts of 4-nitrotoluene-2-sulfonic acid are added in about 1 hour 30 minutes. During that time, the temperature was raised naturally and increased to around 76 ° C in about 1 hour. The mixture is stirred at 77-79 ° C for about 4 hours. The ρΗ of the reaction mixture is about 13. The reaction solution contains about 10% of a sodium salt of a stilbene dye.

Next, 85 parts of concentrated sulfuric acid is added to the reaction solution obtained above in about 30 minutes. When the addition of sulfuric acid is completed, the pH of the reaction solution becomes 7-8. This reaction solution was further stirred at 30 ° C. for 30 minutes. Next, in a separately prepared glass flask, 700 parts of jetylbenzene and 700 parts of tri-n-octylamine were added, and the total amount of the reaction mixture was added to the mixture. Stir for about 1 hour at ° C. Meanwhile, concentrated sulfuric acid was added to the mixture to adjust and maintain the pH at about 4. When the stirring was stopped, it separated into a jetylbenzene phase and an aqueous phase immediately. The light benzene phase containing the tri-n-octylammonium salt of the resulting stilbene dye was poured into the upper layer, and the aqueous phase containing the lower inorganic salt was washed away. Next, 3000 parts of 70 ° C water was added to the jetylbenzene phase containing lipophilic ammonia salt, and the mixture was stirred and washed for 30 minutes, and then the lower aqueous phase was removed.

[0024] Next, 330 parts of an 80% aqueous ethanolamine solution was added to the jetylbenzene phase containing the lipophilic ammonia salt, and the mixture was stirred at 70 ° C for 2 hours. The stilbene dye tree n-octyl ammonium salt is converted to diethanol ammonium salt and separated and transferred to the lower layer. Separate the aqueous phase containing the stilbene dye jetanol ammonium salt, add 20 parts of activated carbon to the aqueous phase, stir and filter. As a result, tri-n-octylamine and jetylbenzene are removed in a small amount in the aqueous phase. Water was evaporated at a temperature of 80 to 90 ° C., the concentration was adjusted, and the mixture was filtered through a filter to obtain 1640 parts of a concentrated aqueous solution of stilbene dye. This concentrated aqueous solution contained about 343 parts of stilbene dye.

[0025] Example 2 Instead of using jetylbenzene, instead of using 1050 parts of tri-n-octylamine which is about 50% excess of the amount required to convert all the sulfonic acid groups of the stilbene dyes to ammonium salts. The same procedure as in Example 1 was repeated. 1640 parts of a concentrated aqueous solution of a stilbene dye excellent in storage stability was obtained. This concentrated aqueous solution contained about 343 parts of stilbene dye.

[0026] Example 3

70. To 2150 liters of C water was added 645 liters of sodium salt of stynoleben dye (prepared from 406 parts of 4-nitrotonolene-2-sulfonic acid) and stirred for 30 minutes to obtain a uniform dispersion. Next, 1050 parts of tri-n-octylamine corresponding to 150% of the number of moles required to convert all sulfonic acid groups to the amine salt was added, and the same operation as in Example 2 was performed. 1640 parts of a concentrated aqueous solution of a stilbene dye having excellent storage stability was obtained. This concentrated aqueous solution contained about 343 parts of stilbene dye.

[0027] Example 4

Trialkylamines containing similar structures equivalent to 200% of the number of moles required to convert all sulphonic acid groups of stilbene dyes to ammonia salts (tri-n-otatylamin 15% , Di-n-octyl-mono-n-de-force-lamine 35%, mono-n-octyl-di-n-de-de-lamine 35%, tri-n-de-l-ramine 15%) 1400 parts The same procedure as in Example 2 was repeated to obtain 1640 parts of a concentrated aqueous solution of stilbene dye having excellent storage stability. This concentrated aqueous solution contained 343 parts of stilbene dye.

[0028] Application examples

After adding 2 parts (dry weight) of pulp into the dye pot, 40 parts of water and 20 parts of the concentrated solution obtained by diluting 2.0 parts of the concentrated aqueous solution obtained in Example 1 to 500 parts were added. The resulting mixture was stirred at room temperature for 15 minutes to make the mixture homogeneous. Next, 2 parts of a 1% sizing agent (FR size 1900 manufactured by Misa Ceramic Chemical Co., Ltd.) was added and stirred for 10 minutes, and then 2 parts of 3% aluminum sulfate was added and stirred for 15 minutes. Using this solution, papermaking and drying were performed according to the method described in JISP-8209 (Paper Test Handsheet Preparation Method) to obtain a paper sheet. The paper thus obtained has a deep yellow color with good wet fastness It was stained.

Claims

The scope of the claims

[1] Yellow azo and / or azoxy stilbene dyes obtained by self-condensation of 4-trotoluene 2-sulfonic acid in the presence of alkali metal hydroxide. According to a method for producing a concentrated aqueous solution excellent in storage stability of the dye by converting to an ammonium salt (primary amine conversion) and then converting to an alkanol ammonium salt (secondary amine conversion). The primary amine transformation with at least one trialkylamine having 12 to 40 carbon atoms and a system of jetylbenzene and water or at least one trialkyl containing 12 to 40 carbon atoms. Using a system of amine and water, and the secondary amine conversion into the trialkylamine and jetylbenzene phase obtained by the primary amine conversion or the trialkylamine phase, Carbon atoms force ^ ~ mono one is four, the preparation of concentrated aqueous solutions of the dye, which comprises carrying out by 添Ka 卩 di one or Toriarukano one Ruamin.

[2] The process according to claim 1, wherein the trialkylamine in the primary amine conversion is a trialkylamine having 12 to 25 carbon atoms.

[3] The process according to claim 2, wherein the trialkylamine having 12 to 25 carbon atoms is tri-n-octylamine.

[4] The production method according to claim 1, wherein the primary amine conversion is carried out in a system of tri-n-octylamine and water in a large excess of an equimolar amount or more.

[5] A mono-, di- or trialkanolamine having 2 to 4 carbon atoms of an aranol group is a di- or trialkanolamine having 2 to 4 carbon atoms of an alkanol group. The production method according to any one of claims 1 to 4.

6. The process according to claim 5, wherein the dialkanolamine having 2 to 4 carbon atoms in the aranol group is diethanolamine.

[7] The process according to any one of claims 1 to 6, wherein the primary amine conversion is performed in a tri-n-octylamine and water system, and the secondary amine conversion is performed by adding ethanolamine.

[8] The production method according to any one of [1] to [7], wherein the primary amine conversion is performed under the acidic condition using the dye synthesis reaction solution as it is.