JPH0587102B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial Application Field The present invention relates to the field of dyeing cellulose fibers. Particularly related to pulp dyeing and dyed paper. (b) Prior Art Although yellow dyeing of paper has been widely practiced in the past, none of these dyes are completely satisfactory in terms of hue, density, high fastness, and economical dyeability, and improvements have been desired. The dye of the general formula () is known as a yellow dye for paper (Japanese Patent Publication No. 55-11708, Japanese Pat.
-36208, JP-A-57-65757). On the other hand, the general formula ()
Dyes such as
−81528). These inventions improve the solubility of dyes and provide powdered or highly concentrated dye solutions suitable for dyeing pulp and cotton. It is said that by dyeing pulp and making paper using these dye solutions, the dyed paper obtained is uniformly dyed, and it is possible to obtain bright, light-fast, and solid yellow paper. (c) Problems to be solved by the invention However, the dye of general formula () has a bright yellow hue, good solubility, good light fastness, and no white water staining, making it suitable for paper dyeing. Among its disadvantages, it has poor build-up properties and the color changes to a reddish tint due to the addition of sulfuric acid. The dye of general formula () has a vivid yellow hue,
This dye has good solubility and good light fastness, making it suitable for paper dyeing, but it has the drawback of being highly contaminated with white water and easily staining paper blankets. Poor build-up properties mean that as the dye concentration increases, the dye should become darker in proportion to it, but the dye does not become darker in proportion. White water pollution refers to when dyes are not sufficiently adsorbed to the pulp during pulp dyeing, resulting in colored wastewater. If white water contamination is bad, there will be problems such as increased contamination of blankets used during paper making and troublesome wastewater treatment. (d) Means for Solving the Problems The inventors of the present application have conducted extensive studies on dye compositions that do not have these drawbacks, and have completed the present invention. That is, the present invention provides: (1) A yellow dye composition containing dyes of the following formulas () and () in the form of free acids in a weight ratio of 20:80 to 90:10.

[ka] (In the formula, X represents an alkanolamine residue.)

(2) A solution-like yellow dye composition comprising the yellow dye composition described in (1) above. (3) A method for dyeing pulp, characterized by using the yellow dye composition described in (1) and (2) above. (4) A dyed pulp characterized by using the yellow dye composition described in (1) and (2) above. (5) Paper made of dyed pulp, characterized by using the yellow dye composition described in (1) and (2) above. (6) A yellow solution dye composition obtained by adding urea and/or alkanolamine to the yellow dye composition described in (2) above. It is. It has been found that if the dyes of formulas () and () are used individually, these objectives are not achieved at all, but that when mixed in the proportions of the present invention, all the above-mentioned disadvantages are overcome by a synergistic effect, and the present invention has been made. Completed the invention. Such an effect is a surprising phenomenon that even those skilled in the art could not have predicted. Examples of the alkanolamine residue of X in the dye of formula () include monoethanolamine, diethanolamine, monopropanolamine, dibropanolamine, monoisopropanolamine, diisopropanolamine, N-methylethanolamine, N-ethylethanolamine, N Dyes having diethanolamine residues are particularly suitable, although residues such as -phenylethanolamine are suitable. Examples of the salts of the sulfonic acid group of formula () and formula () include Li, Na, K, NH ₄ , ammonium ions of alkanolamines, such as NH ₃ (C ₂ H ₄ OH),
H ₂ N (CH ₂ CH ₂ OH) ₂ , HN (CH ₂ CH ₂ OH) ₃ , N
(CH ₂ CH ₂ OH) ₄ , NH ₃ (C ₃ H ₆ OH), NH ₂
(C ₃ H ₆ OH) ₂ , NH (C ₃ H ₆ OH) ₃ , NH
_{( CH2CH2OCH2CH2OH ) 3 ,} NH
[(CH ₂ CH ₂ O) ₃ CCH ₂ CH ₂ OH] ₃ , H ₂ NCH ₃
(CH ₂ CH ₂ OH) etc. are suitable. The position of the sulfonic acid group in the benzene nucleus in formula () may be o-, m-, or p-position with respect to the azo group, but the m-position is particularly preferred. These dyes can be prepared using known methods (Japanese Patent Publication No. 55-11708, Japanese Patent Publication No. 47-8526).
etc.) and is used in powder or granule form, or in some cases in liquid form. Liquid products are preferable in terms of working environment pollution and automatic metering. Usually 5 to 50% as dye content, more preferably 7
A solution composition containing ~20% is provided. This effect is exhibited when the free acids are mixed at a weight ratio of 20:80 to 90:10, but the preferred ratio is 50:50 to 80:20. be. These may be mixed in powder or liquid form. It is also possible to mix just before use. In the case of a liquid, it is necessary to decide the concentration of the dye, the type of counter ion, the concentration of the mixed inorganic salt, the amount of the solubilizer added, etc., taking into account the stability and economic efficiency of the solution. In particular, dyes of formula () tend to precipitate due to the presence of Na and K ions, so it is desirable to keep the concentration of these ions in solution as low as possible. It is usually desirable that the content be 2% or less, but even if it exceeds 2%, precipitation can be prevented by increasing the addition of the solubilizing agent. As the solubilizing agent, various known ones used in aqueous dye solutions can be used. For example, methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, methyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, glycerin, methyl isobutyl carbinol, polyethylene glycol, propylene glycol, polypropylene glycol, polyoxyethylene polyoxypropylene copolymer Alcohol derivatives such as coalescence, formamide, dimethylformamide, urea, guanidine,
Amide compounds such as dicyandiamide, hexamethyllyamide phosphate, acetamide, dimethylacetamide, dimethylurea, tetramethylurea, ethanolamine, diethanolamine, triethanolamine, isopropanolamine,
Alkanolamines such as diisopropanolamine, triisopropanolamine, and ethyldiethanolamine, and their salts; various nonionic, anionic, and cationic surfactants; and other dioxane, dimethyl sulfoxide, ethylene carbonate, ε-caprolactam, pyridine, picoline, and sulfolane. , N-methylpyrrolidone, polyvinylpyrrolidone are used. Among these, urea compounds and alkanolamines are optimal in terms of economy and efficacy. . In addition, antifoaming agents and antifungal agents may be added depending on the case. Although the present dye composition can be used for dyeing cellulose fibers in general, it is particularly suitable for dyeing pulp. Usual pulps include LBKP (Large Leaf Pulp) and NBKP.
It is widely used for (softwood pulp), mixed pulp of LBKP and NBKP, or mixed pulp of these and waste paper. The conditions for pulp dyeing are known methods, such as Japanese Patent Publication No. 55-11708,
JP-A-57-65757 and JP-A-47-8526 apply. (e) Examples % represents weight %. owp (=on weight of pulp) represents the weight ratio to the pulp dry weight. An aqueous dye solution was prepared as follows. Dye aqueous solution A (formula () dye aqueous solution): Water 87.4% Lower formula dye of formula (-1) 9.5% (9.0% as free acid) Diethanolamine hydrochloride 1.6% Diethanolamine 0.5% Salt 1.0% (Total 100%)

[Cat] λmax399nm, absorbance E of this solution 150mg/=
0.948 dye aqueous solution B (dye aqueous solution of formula ()): Water 71.2% Lower formula dye of formula (-1) 9.5% (7.2% as free acid) Urea 7.0% Triethalamine 2.8% Diethanolamine 9.5% (Total 100% )

[C] λmax412nm, absorbance E of this solution 150mg/=
0.948 Dye aqueous solution C: Dye aqueous solution C is a mixture of 25 g of dye aqueous solution A and 25 g of dye aqueous solution B. Dye aqueous solution C contains 25×9.0/100=2.25 g of the dye of formula (-1) as a free acid. 25X7.2/10 dye of formula (-1) as free acid
Contains 01.80g. Therefore, formula (-1): formula (-
The weight ratio of 1) is 2.25:1.80 = 56:44 as free acid.
corresponds to Dye aqueous solution D: Dye aqueous solution D is a mixture of 37.5 g of dye aqueous solution A and 12.5 g of dye aqueous solution B. Formula (-1) of this: The weight ratio of formula (-1) is as the free acid
Equivalent to 79:21. Dye aqueous solution E: Dye aqueous solution E is a mixture of 12.5 g of dye aqueous solution A and 37.5 g of dye aqueous solution B. Formula (-1) of this: The weight ratio of formula (-1) is as the free acid
Equivalent to 30:70. Examples 1 to 3 Dye aqueous solution C Prepare three beakers containing 250 ml of NBKP pulp liquid (pulp dry weight 5.0 g) adjusted to a concentration of 20 g at room temperature, and add dye aqueous solution C while stirring with a propeller type stirrer. Diluted with water to 50g/
Add 2.5 ml, 5.0 ml, 7.5 ml (corresponding to 2.5, 5.0, 7.5% owp of dye stock solution based on pulp dry weight),
After 5 minutes, add sulfuric acid band 1.5% OWP to each, and after another 5 minutes add Size Pine E (manufactured by Arakawa Chemical Co., Ltd.) to each.
After 10 minutes, 0.15% OWP was added, stirring was stopped, each was diluted to 1 with water, and paper was made using a TAPPI paper machine and dried to obtain yellow dyed paper. Examples 4 to 6 Aqueous Dye Solution D Yellow dyed paper was obtained using the aqueous dye solution D in the same manner as in Examples 1 to 3. Examples 7-9 Aqueous Dye Solution E Yellow dyed paper was also obtained using the aqueous dye solution E in the same manner as in Examples 1-3. Comparative Examples 1 to 3 Aqueous Dye Solution A Yellow dyed paper was also obtained using the aqueous dye solution A in the same manner as in Examples 1 to 3. Comparative Examples 4 to 6 Aqueous Dye Solution B Yellow dyed paper was also obtained from the aqueous dye solution B in the same manner as in Examples 1 to 3. According to JIS Z 8729, these dyed papers are
A* and b* of the Hunter chromaticity diagram were determined using a Macbeth 200plus colorimeter. The results are shown in Table 1.
It is shown in Fig. 3.

[Table] Figure 1 shows the surface concentration of yellow.
The relationship between * and the amount of dye aqueous solution used %owp is shown. From the results in Figure 1, A of formula (-1), formula (-
Compared to the build-up properties of each B dye of 1) alone, the weight ratio of formula (-1): formula (-1) is 56:44,
It can be seen that the build-up properties of the mixture of 79:21 D and 30:70 E are clearly superior. Figure 2 is a Hunter chromaticity diagram showing the hue relationship of dyed paper. From the results in Figure 3, equation (-1): equation (-1)
The weight ratio of dyes is C: 56:44, D: 79:21 and 30:
The dyed paper used in E of 70 is located on the plus b* side of the center line M of formula (-1) alone A and formula (-1) alone B, and has a yellowish tinge than the center line M (average value). It shows that it is clear. (The meaning of the center line is Formula (-1): Formula (-1) The weight ratio of the dye is
Equation (-1), which corresponds to the arithmetic mean value of 50:50:
Even if D has a weight ratio of 79:21 according to formula (-1), the fact that it is on the plus b* side from the center line M indicates that a synergistic effect is produced by mixing A and B. Examples 10 to 12, Comparative Examples 7 to 8 50g/aqueous dye solution of A, B, C, D and E
The pulp was dyed, made into paper, and dried under the same conditions as in Example 1, except that 7.5 ml (corresponding to 7.5% owp of the dye stock solution based on the dry weight of the pulp) was used. Fade−Meter (Carbon
Light fastness was measured using Arc lamp) (JIS L0804
Judging by fading gray scale). The degree of coloration of the effluent after paper making (white staining) and the degree of coloring of the filter paper used during papermaking (filter paper staining) were visually determined. Degree of coloring (visual judgment) ◎: Extremely low ○: Low △: Slightly high ×: High The results are shown in Table 2.

[Table] From this result, the light fastness of dye A of formula (-1) was greatly improved by using a mixture of dyes of formula (-1) and formula (-1). Dye B of formula (-1) has good light fastness, but
White water contamination and filter paper contamination are bad. However, these drawbacks were largely improved by using a mixture of dyes A of formula (-1) and B dyes of formula (-1). Examples 14 to 17, Comparative Examples 9 to 16 As shown in Table 3, dye aqueous solutions A, B, and C were used at 5.5% owp based on the pulp dry weight, the order of addition of sulfuric acid band and size pine was reversed, and the treatment time was was shortened and stained. Standard staining method: 250ml of NBKP pulp solution adjusted to a concentration of 20g/
Prepare two pieces, and add 5.5ml of dye aqueous solution diluted with 50g/water to each (based on the dry weight of the pulp).
(equivalent to 5.5% owp) of the dye stock solution was added, and after 5 minutes, 1.5% owp of sulfate and 3.0% owp were added.
After a further 5 minutes, Size Pine E (manufactured by Arakawa Chemical Co., Ltd.) 0.15% owp was added to each, and after 10 minutes, it was diluted with water to 1 part, and the paper was dried to obtain yellow paper. Pre-dyeing method: In contrast to the standard dyeing method, first add sulfuric acid bands to Size Pine E (manufactured by Arakawa Chemical Co., Ltd.), add an aqueous dye solution after 3 seconds, dilute to 1 with water after 30 seconds, and dry the paper to make yellow paper. Obtained. Each yellow paper discoloration color scale (Y) (JIS
L0804) was determined using the standard staining method as the standard (St).

[Table] From the results in Table 3, it can be seen that the use of dye A of formula (-1) alone has the drawback of being susceptible to discoloration and fading when sulfuric acid is added. The greater the amount of sulfate bands, the more remarkable the discoloration and fading will be in the pre-staining method than in the standard staining method. When dye B of formula (-1) is used alone, it is difficult to discolor or fade, but it has the disadvantage of staining with white cedar water. In the case of a mixture of A dye of formula (-1): B dye of formula (-1) = 56:44, the discoloration and fading are equivalent to the case of B dye of formula (-1) alone, and there is no white water pollution. Improved. Examples 18-22 The formula of the aqueous dye solution A used in Example 1 (-
1) Instead of the dye, use a solution containing the dye shown in formula (1-2) in Table 4 at the same absorbance concentration as A, and in place of the dye of formula (-1) in dye aqueous solution B, use the dye shown in Table 4 (-
A mixed solution with a free acid polymerization ratio of 79:21 was prepared using a dye containing the dye shown in 1) at the same absorption density as B. The pulp was dyed using the same dyeing method as in Example 1, and the results of hue, light fastness, and white water staining are summarized in Table 5. In either case, a bright yellow paper with excellent light resistance was obtained, and almost no white water staining was observed.

[ka]

[ka]

【table】

[Table] Example 23 Dye aqueous solution A used in Example 1 Using the dye of the following formula instead of the dye of formula (-1), dye aqueous solution B and
Dyeing was carried out in the same manner as in Example 1 except that they were mixed at a ratio of 75:25 (free acid weight ratio 79:21). A bright yellow dyed paper was obtained, with good light fastness and white water staining.

[Chemical formula] Examples 24 to 30, Comparative Example 17 Storage stability of aqueous dye solution In place of the aqueous dye solution B, an aqueous dye solution B' having the following composition was prepared. Dye of formula (-1) 13.7% (10.3% as free acid) Triethanolamine 4.1% Water 82.2% (100%) To a mixed solution of 70 g of dye aqueous solution A and 20 g of dye aqueous solution B', add the auxiliary agents listed in Table 6, Total including water
100g of mixed solution was prepared. Dye aqueous solution A contains 70×9.0/100=6.30 g of the dye of formula (-1) as a free acid. dye aqueous solution
B' is 20X10 using the dye of formula (-1) as the free acid.
Contains 3/100=2.06g. Therefore, formula (-1):
The weight ratio of formula (-1) corresponds to 6.30:2.06=75.25. Pour these solutions into a 200ml glass pin for 25 minutes.
The product was stored at ℃ and the stability was checked by checking whether a precipitate was formed after 3 or 6 months. The storage stability was better with the addition of the auxiliary agent.

[Table] (f) Effects The first effect of dyeing using this dye composition is that it has a high degree of coloration, so-called build-up property. The second is excellent light fastness, and the third
Another advantage is that the hue of the dyed product does not change depending on the amount of sulfuric acid used for pulp dyeing, and a constant hue can be obtained. This is particularly advantageous for high speed dyeing. Further effects include reducing the degree of coloration of wastewater (white water contamination) and reducing the color contamination of paper blankets. By using the yellow dye composition of the present invention, it is possible to contribute to the rationalization of pulp dyeing, such as reducing the amount of dye used, stabilizing the quality of yellow paper due to stable hue, reducing dyeing costs, and improving light fastness. There is something big.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between b* value and dye usage percentage (owp) for Examples 1 to 9 and Comparative Examples 1 to 6. Figure 2 is
This is Hunter's chromaticity diagram. FIG. 3 shows Examples 1 to 9,
It is a Hunter chromaticity diagram of Comparative Examples 1 to 6.

Claims (1)

[Scope of Claims] 1. A yellow dye composition comprising dyes of the following formulas () and () in the form of free acids in a weight ratio of 20:80 to 90:10. embedded image (In the formula, X represents an alkanolamine residue.) embedded image 2. A solution-like yellow dye composition comprising the yellow dye composition according to claim 1. 3. A method for dyeing pulp, which comprises using the yellow dye composition according to claim 1. 4. A method for dyeing pulp, comprising using the solution yellow dye composition according to claim 2. 5. A dyed pulp characterized by using the yellow dye composition according to claim 1. 6. A dyed pulp characterized by using the solution yellow dye composition according to claim 2. 7. A yellow solution dye composition obtained by adding urea or/and alkanolamine to the solution yellow dye composition according to claim 2.