KR19980024583A - Processes for preparing high activity sulfonated lignin dye dispersants and dye mixtures containing the same high activity sulfonated lignin dye dispersants and the same - Google Patents

Abstract

Dye dispersants in improved dye mixtures consisting of dye cakes and dye dispersants have been shown to consist of sulfonated or sulfomethylated lignin of increased activity and improved thermal stability and the dispersants of low molecular weight elements of sulfonated and sulfomethylated lignin It is shown to be prepared by substantial removal. Exclusion of the low molecular weight portion of the dispersant is by fractionation of sulfonated or sulfomethylated lignin to remove substantial portions of molecules having a molecular weight of less than 3,000. Instead, in the case of sulfate or soda, lignin recovered from the wood pulp process, lignin will be fractionated so that substantial portions of molecules having molecular weights less than 3000 prior to sulfonation or sulfomethylation are removed.

Description

Processes for preparing high activity sulfonated lignin dye dispersants and dye mixtures containing the same high activity sulfonated lignin dye dispersants and the same

The present invention is directed to methods for improving the activity and thermal stability of new and improved sulfonated lignins and sulfonated lignins useful as dye dispersants.

Dye mixtures generally consist of dye cakes and dye cakes of dispersants and / or diluents. These dye mixtures are widely used to dye both natural and synthetic fibers. Dispersants in dye mixtures have three basic functions; (1) it helps to reduce dye particles to fine size; (2) it contains a dispersing medium; And (3) it is used as a diluent.

Dye dispersants are generally one of two main forms: (1) sulfonation from the woodpulp industry, which manufactures lignocellulosic materials, such as wood, straw, corn stalks, vargas and the like, by separating cellulose or pulp from lignin. Lignin (either sulfite pulp method or via kraft pulp method) or (2) naphthalene sulfonates from the textile industry. The present invention relates to dispersants of sulfonated lignin dyes. Sulfite (or bisulfite) woodpulp method Lignin is recovered as lignosulfonate from discharged pulp liquor known as black liquor; The craft (or sulfate) woodpulp method lignin is recovered from the black liquor to the sodium salt of lignin (products sold by Westvac Corporation under the Indulin ^R macro).

The recovered lignin dye dispersants for use in the ^(R Polyfon, Kraftsperse ^R and ^R marks Westvaco Reax the products for sale by the Corporation) is methylated sulfonated or sulfo. As used herein, the term sulfonated lignin will generally be used to refer to lignosulfonates, sulfonated lignins or sulfomethylated lignin as described above.

The advantages of using sulfonated lignin as dispersants in dye mixtures have excellent physical properties, including (1) availability and (2) good combination and remarkable dispersibility for many dye systems at ambient and elevated temperatures. . However, there are many drawbacks to using lignin as a dispersant, whether they are sulfite lignin or craft sulfonated lignin. These negative factors include fiber staining of the lignin used (because the lignin is brown in the dry powder form) and thermal stability (since the dyeing process is performed at high temperatures). These disadvantageous properties are cumbersome for dye manufacturers and many attempts have been made to overcome these drawbacks.

Numerous technological advances have denatured sulfonated lignin, reducing the negative side of using such materials as dye dispersants without causing any major adverse effects on the new methods and their properties of making the desired sulfonated lignin with dye dispersants at the same time. It gave birth to ways. US. Patent No. In 4,001,202 a sulfonated lignin having improved fiber dyeability useful as a dye dispersant by reacting lignin with epihalohydrin is described. Also U.S. Patent No. 4,338,091 teaches reacting denatured lignin with sodium sulfite and aldehydes; Lignin has been denatured by pretreatment with sodium ethionate.

Additional embodiments for reacting or denaturing lignin which make them more suitable with dye dispersants are described in U.S. Pat. Patent No. 4,184,845, 4,131,564, 3,156,520, 3,094,515, 3,726,850, 2,680,113 and 3,769,272. The example technique shows an aspect of the technique but does not tend to include all of the lignin denaturation.

Although the above method for the treatment and preparation of sulfonated lignin has provided some advantages during dyeing, none has been able to produce a product with improvements obtained by improved products made according to the claimed method. .

During the dyeing process only the dye is depleted over the fibers becoming intimate parts of the fibers. Lignin and other dyeing aids remaining in the effluent need to be treated continuously in the first and second waste treatment plants. Although lignin is a natural substance, lignosulfonates are considered relatively non-biodegradable (although they are more biodegradable than synthetic dispersants from the petroleum industry), and they are often the capacity of dye plants or authorities' wastewater treatment facilities. It appears to be environmentally disadvantageous because it exceeds.

One solution to this task would be to increase the dye dispersion activity of the lignin dispersants. (The term vigor refers to the relative amount of dispersant needed to function effectively. The less dispersant needed to perform, the higher its activity; on the other hand, the more dispersant required to perform, the lower its activity.) The increased activity will reduce the amount of additive needed to dye and thereby reduce the wastewater treatment problems present.

It is therefore a general object of the present invention to provide sulfonated lignin of improved properties to increase their usefulness as dye dispersants.

A special object of the present invention is to increase the amount of sulfonated lignin dispersants.

Another object of the present invention is to provide a method for improving the thermal stability of dye preparations containing sulfonated lignin.

Other objects, features and advantages of the invention will be set forth in the following detailed description of the invention.

1 is a graphical representation of thermal stability data consisting of various molecular weight moieties of lignin that are continuously sulfonated and using Disperse Orang 30 dye as a dye dispersant.

FIG. 2 is a graphical representation of thermal stability data consisting of various molecular weight moieties of lignin that were continuously sulfonated and used Disperse Red 167: 1 dye as the dye dispersant.

FIG. 3 is a graphical representation of thermal stability data for the disulfide molecular weight portions of two lignins using the Disperse Red 167: 1 dye and the relative dye dispersants of their combinations.

FIG. 4 is a bar graph of thermal stability data for the composition of the relative molecular weight portions of sulfonated lignin dye dispersants and commercial sulfonated lignin dye dispersants using Disperse Orange 30 dye.

FIG. 5 is a bar graph of thermal stability data for the composition of the relative molecular weight portions of sulfonated lignin dye dispersants and commercial sulfonated lignin dye dispersants using Disperse Red 167: 1 dye.

FIG. 6 is a bar graph of thermal stability data for the composition of the relative molecular weight portions of sulfonated lignin dye dispersants and commercial sulfonated lignin dye dispersants using Disperse Blue 79: 1 dye.

FIG. 7 is a bar graph of thermal stability data for the composition of the relative molecular weight portions of sulfonated lignin dye dispersants and commercial sulfonated lignin dye dispersants using Disperse Blu 60 dye.

FIG. 8 is a bar graphical representation of thermal stability data compared to a commercial (unsorted) sulfonated lignin dye dispersant with various additions of specific molecular weight portions of the sulfonated lignin dye dispersant using Disperse Orange 30 dye.

FIG. 9 is a bar graph of thermal stability data compared to a commercial (unsorted) sulfonated lignin dye dispersant with various additions of a particular molecular weight portion of the sulfonated lignin dye dispersant using Disperse Red 167: 1 dye. to be.

FIG. 10 is a bar graph of thermal stability data compared to a commercial (unclassified) sulfonated lignin dye dispersant with various additions of a particular molecular weight portion of the sulfonated lignin dye dispersant using Disperse Blue 79: 1 dye. to be.

FIG. 11 is a bar graphical representation of thermal stability data compared to a commercial (unsorted) sulfonated lignin dye dispersant with various additions of specific molecular weight portions of the sulfonated lignin dye dispersant using Disperse Blue 60 dye.

Summary of the invention

The amount of sulfonated and sulfomethylated lignin useful as dye dispersants in dye mixtures can be dramatically increased with the improvement of thermal stability of lignin by sulfonation and at least removal of a substantial portion of the low molecular weight component of sulfonmethylated lignin. Preferably essentially all of the low molecular weight elements of sulfonated and / or sulfoethylated lignin are removed. Instead, similar improvements in dye dispersant properties can be obtained by removing at least a substantial portion of the low molecular weight urea of lignin recovered from the black liquor and subsequently sulfonating or sulfomethylating the high average molecular weight lignin urea. Preferably essentially all of the low molecular weight elements of lignin are removed and the remaining high average molecular weight lignin material is sulfonated and / or sulfomethylated.

Description of Preferred Embodiment (s)

Lignin is an amorphous phenylpropane polymer bound to cell wall polysaccharides of most solids. Since lignin is formed in disordered properties, the complete three-dimensional structure of lignin is not yet known. Despite the degraded study of lignin samples from various plants, it has been shown that lignin polymers consist primarily of coniferyl, coumaryl and cinafil alcohols polymerized by plant peroxidase in the free radical method and this free radical reaction Elicit their irregular structure.

Lignins recovered from any known wood pulp method will be used in the method of the present invention; But preferably they are obtained from the kraft wood pulp method in which natural lignin is present as the sodium salt. In the kraft pulp process, wood exhibits a strong alkali effect that lowers the natural lignin in many ways, giving a range of lignin that can be recovered at different molecular weights. Lignins recovered in this process form soluble sodium salts that are separated from cellulose and are soluble in pulp liquid. Lignin is recovered from the discharged pulp solution known as black liquor by lowering the pH of the black liquor to the point where the lignin salt is not dissolved (˜pH 9-10).

The pH drop of black liquor containing lignin salt is easily achieved by the introduction of acidic substances such as carbon dioxide. In reducing the pH by adding acid to the black liquor, phenolic acid groups are converted to their free phenol or acid form on the lignin molecule in ionic form. This conversion renders lignin insoluble in the black liquor and as a result it precipitates.

Alkali lignin recovered from the black liquor by this precipitation method is a water insoluble product. Lignins obtained from kraft, soda, or other alkali methods to which the present invention is directed will not be recovered as sulfonated products but will be sulfonated continuously by reaction of such materials with bisulfite or sulfite. Sulfonated lignin is any lignin that contains a sufficient amount of sulfonic acid groups to at least dissolve in water in a suitable acidic and high pH solution. Substantially low molecular weight moieties in recovered lignin that are lignin sulfonicated and / or sulfomethylated (see Table 2) lignosulfonates (see Table 4) or sulfonic lignins (see Table 1). This exists.

Dilling's U.S. Patent No. 4,551,151 showed that lignin having a molecular weight of about 5,000 or less affected the performance of the dye mixture thermal stability of certain sulfonated lignin materials in succession. Dilling teaches the oxidation of alkaline black liquor containing lignin salts at a pH that remains negligible with high molecular weight lignin products, with almost negligible amounts of lignin having a molecular weight of about 5,000 or less. did.

One of the challenges in the Dilling (U.S. 4,551,151) method is that the release of lignin from black liquor via acid addition broadly involves the ionization of phenolic acid groups that precipitate lignin over proton addition. Salt precipitation also occurs as a result of excessively high electrolyte concentrations generated during the oxidation step. Because of their size, the low molecular weight portion must remain in solution longer than high molecular weight lignin, assuming that the number of protons is the same. Separation of the low molecular weight moiety based on pH control followed by filtration has the highest number of hydrophilic phenols with acid that varies with other neighboring functionality. This only changes so much the solubility-pH relationship that makes the separation of low molecular weight lignin impossible. In fact, the maximum of low molecular weight moiety 5,000 removal by the patented method always involves removing a substantial portion of the middle molecular weight moiety. In addition to losing the positive contribution of this material to the desired dispersibility, the separation process is very ineffective and therefore disadvantageous in cost.

In the present invention, there is no particular lignin free in black liquor as taught by Dilling (U.S. '151). Moreover, the fractionation of sulfonated and sulfomethylated lignins does not depend on pH control.

In contrast to the ionization precipitation principle, the separation of the present invention is based only on molecular size separation. The removal of low molecular weight from various sulfonated sulfite lignins and sulfomethylated and sulfonated kraft lignin occurs without disturbing the functional groups in the lignin so that the present method in turn is a huge advance in the separation process providing a highly improved sulfonated lignin dispersant product. It will be apparent from the following examples. The process of the present invention not only provides a dispersant of generally improved and high active dyes, but also allows dispersant manufacturers to tailor a particular dye to a particular dye system.

On separation (ie oxidation, condensation and filtration / tilting) with conventional lignin glass, the next step in improving conventional lignin-based dye dispersants is to sulfonate lignin as appropriate. It will be mentioned that the degree of sulfonation of lignin is proportional to the solubility of lignin in aqueous solutions and the viscosity of such lignin. So measuring the solubility of sulfonated lignin is one way to determine its degree of sulfonation.

One of the conventional methods of sulfonating lignin involves sulfomethylation of alkaline lignin by reacting sodium sulfite with formaldehyde such lignin. This method is described in E. Adler et al. in US Patent No. 2,680,113. Sulfomethylation is carried out on the aromatic nucleus of the lignin molecule in such a way that the -CH ₂ SO ₃ H group is bonded to the aromatic nucleus of the lignin. Alder taught that the treatment of lignin with such sulfonating agents is carried out at temperatures ranging from 50 ° C. to 200 ° C., suitably from 80 ° C. to 170 ° C., preferably from 100 ° C. to 160 ° C. The amount of sulfite used, calculated as anhydrous sodium sulfite, will vary from about 10% to 100% of the anhydrous lignin amount and the amount of aldehyde will be equal to or less than the sulfite, i.e. about 1% calculated for the amount of anhydrous lignin material. Falls. The treatment is preferably carried out in an alkaline solution.

Alkanri lignin will also be sulfomethylated in which alkali lignin mixes with water to form a slurry. To the slurry is added a sulfomethylating agent, ie sodium sulfite and formaldehyde. The ratio of sodium sulfite to formaldehyde varies from about 1.1: 0.1 to about 2.5: 1.0, with a preferred range of about 1.3: 0.8. Excessive addition of sodium sulfite compared to formaldehyde has been known to yield sulfonated lignin products with reduced molecular weight.

Almost simultaneously when formaldehyde and sodium sulfite are combined in stoichiometric amounts they form hydroxy methane sulfonate and they alternately react with lignin to form sulfonated lignin derivatives. The hydroxy methane sulfonate intermediate is present in the desired form only up to 90%, whereas always 10% of the reactants are present. The problem with having 10% of the reactants present is that the formaldehyde reacts with the lignin being sulfomethylated. So it would be advantageous to have as little unreacted formaldehyde in the reaction mixture as possible. This can be done by various molar ratios of sodium sulfite to formaldehyde. Increasing the sodium sulfite to formaldehyde molar ratio resulted in the use of the residual amount of unreacted formaldehyde to produce more amounts of hydroxy methane sulfonate intermediate. The increased amount of sodium sulfite lowered the degree of polymerization further, resulting in sulfonated lignin with low molecular weight.

In a further sulfonation method, the precipitated lignin is preferably pickled with sulfuric acid and dried to produce a lignin material having a pH that varies from about 1.5 to about 5.0. When lignin combines with water to form a slurry of about 25% solids, lignin is present in this pH range in precipitated form. If the pH of the lignin slurry is less than 5, the pH is raised to about 5.0 by using sodium hydroxide. At this point sodium sulfite is added to raise the initial pH of the reaction product in the range of about 7.0 to 7.5.

Sulfonation consists of the addition of formaldehyde which raises the pH of the slurry to the range of about 8.0 to about 9.2. The slurry is then obtained at a temperature in the range from about 130 ° C. to about 175 ° C., preferably about 140 ° C. The temperature is maintained for a maximum of preferably about 2 hours for a time ranging from about 30 minutes to 12 hours.

The use of low pH and low temperature has two advantages. For one, lignin is unlikely to degrade under these conditions than under normal reaction conditions. The fact that sulfonation occurs at low pH means that the resulting sulfonated lignin product will possess a lower pH than can be obtained by other methods.

When sulfonated lignin is used as dye dispersants, the pH of such lignin preferably varies from about 4 to about 8. If lignin is sulfonated at high pH, the resulting sulfonated lignin will have a high pH. For compression cake makers that use such sulfonated lignin as a dispersant, dye manufacturers require acid addition to such lignin up to low pH, which converts additional losses. Sulfonation of lignin at low pH results in sulfonated lignin, which requires little or no acid to make the proper sulfonated lignin as a dispersant.

This is all of the sulfonated and sulfomethylated lignins of the sulfite or alkaline pulp process to which the process of the present invention is directed, as well as the sulfonated lignin of other prior art. Improved sulfonated or sulfomethylated lignin dye dispersants are provided by the necessary removal of portions of sulfonated or sulfomethylated lignin that exhibit a molecular weight of less than 3,000, preferably less than 10,000. Since sulfonation or sulfomethylation increases a slight amount of lignin molecular weight, the improved lignin dispersants of the present invention in the case of lignin recovered from sulfate, soda or other alkaline pulp methods have molecular weights of less than 3,000 (preferably less than 10,000). It will also be provided by fractionation of the recovered lignin from which substantial portions of the molecules are removed, followed by sulfonation and / or sulfomethylation of the remaining high molecular weight lignin portion. The absence of this low molecular weight moiety essentially increases the average molecular weight of the lignin dispersant but the mixtures of the present invention are not limited to a particular range of average molecular weights. This is because an increase in average molecular weight can result from others than the absence of this low molecular weight moiety.

The method or means of removing (or at least substantially removing) this low molecular weight moiety is not critical. The main subject of the present invention relates to an improved sulfonated lignin dye dispersant which essentially eliminates only the low molecular weight portion. Because of the various methods of molecular weight determination that can lead to different results, the invention is characterized by substantial filtration as determined by single filtration and (or preferably characterized by substantial absence of molecules of less than 10,000 molecular weight) as determined by Han filtration. A sulfonated (or sulfomethylated) lignin dye dispersant. In particular, the ultrafiltration used in the operations described herein is ultrafiltration through a 3,000 molecular weight membrane (or very preferably 10,000 molecular weight membrane) in Amicon (or similar) ultrafiltration units. The presence of sulfonated lignin in the low molecular weight moiety provided by ultrafiltration as described in Example 1 is determined by gel osmosis chromatography (GPC). Devices using disk membranes are suitable for laboratory scale while devices using threaded membranes allow for high throughput and are desirable for large scale processes.

One alternative method of removing or substantially eliminating the low molecular weight portion of lignin / sulfonated lignin to combine with the dyes resulting in the improved dye mixture of the present invention will include reversible osmosis. Another alternative method of substantially reducing the low molecular weight portion of lignin / sulfonated lignin is (a) a lignin substance followed by sulfonation and / or sulfomethylation or (b) a low molecular weight portion of sulfonated and / or sulfomethylated lignin. Crosslinking. It will also minimize product loss in continuous separation by reducing the size of the low molecular weight moiety by pre-crosslinking.

Sulfonated lignin prepared according to the invention can be used in dye mixtures as dispersants. The required amount of such dispersant will vary depending on the particular dye cake, the material to be dye and the desired effect. The most important factor in determining the proper amount of dispersant mixture used to make the dye is the particular dye cake used. Generally this amount will vary with the dye.

The following are only examples and are not intended to limit the invention.

Example 1

Lignin recovered by low pH precipitation from black liquor (Indulin ^R A) of kraft wood pulp method was fractionated into 5 molecular weight fractions by ultrafiltration in order to confirm the relationship between the structure-property-performance of lignin in dyes related to application. did. Fractionation was performed on Amicon RA 2000 ultrafiltration units using Amicon threaded membranes. pH was adjusted to 11 with 50% NaOH and solids to 10%. Indulin was filtered through 100K, 30K, 10K and 3K membranes respectively. Each part was washed until the discharge stream was clean. The molecular weight data of the parts determined by gel osmosis chromatography (GPC) are shown in Table 1.

Indulin ^R part Mn ¹ Mw ² Mz ³ Yield% 100 K 600 25900 48000 18 30K100K 180 6300 13400 18 10K30K 130 4000 9000 33 310K 80 1900 4500 11 3K 40 1200 3100 20 ¹ Medium molecular weight ² Average molecular weight ³ Maximum molecular weight

The average molecular weights of the parts shown in Table 1 were obtained by preparing lignin samples at a concentration of 1 mg / ml based on% wt / wt solids in an aqueous fluidized bed (20:80 acetonitrile to 0.1 N sodium nitrate mixture, pH 11.0). decided. Lignin samples were allowed to equilibrate for at least 8 hours and filtered through a 0.45 micron filter prior to analysis. 100 μl of aliquot was injected into four Waters ^R Ultrahydragel columns (1000, 500, 250 and 120 mm 3) equilibrated to 40 ° C. Peaks were found up to 280 NM with a Waters ^R Model 486 UV Tower Keeper (UV486) set. A narrow standard of polystyrene sulfonate was used to create the calibration curve. The goodness of fit of the curve is primary to the forced origin.

The other portions were sulfonated at three different degrees, respectively, for the 1.1, 1.5 and 2.4 gram scattering points. As described above, the degree of sulfonation was effectively measured using a solubility measuring instrument. Thus, the degree of sulfonation was determined by the amount of grams of 10 N sulfuric acid required to initiate precipitation of lignin in the solution (0.175 g based on solids and diluted with 35 g of distilled water). The 3K moiety probably is not sulfonated because the side chain reaction moiety is small, but this moiety is sulfomethylated up to a point 1.5. Once the moiety is sulfonated, there is no significant change in molecular weight.

Thermal stability of the other sulfonated moieties was determined by package dyeing using hydrophobic dyes (Disperse Red 167: 1) and hydrophilic dyes (Disperse Orange 30) (Zeltex package-dyeing unit from Werner Mathis, ie 1 L / min, 70 ° C). -130 ° C, ＠ 2 ° C / min, vessel pressure of 2 bar). The results of this test are graphically shown in FIGS. 1 and 2 compared to the results for Reax ^R 85A (a conventional sulfonated lignin dye dispersant considered by industry showing high thermal stability).

The 10K 30K and 30K 100K parts had the highest thermal stability and were equal to or better than the standard, Reax ^R 85A, in the two dyes tested. The solubility of these two parts did not affect the thermal stability.

The 100K and 3K 10K portions were less than or equal to Reax ^R 85A in terms of thermal stability and were dependent on thermal stability. The thermal stability of 100K fraction using Disperse Orange 30 was sharply lowered and the solubility increased. This did not occur in all of the sulfonation degrees, in thermally stable dyes such as Reax ^R 85A, and in Disperse Red 167: 1. Thermal stability at 3K 10K fraction decreased with increasing solubility in both dye tests. However, this trend is more evident in Disperse Red 167: 1. At the lowest molecular weight fraction, 3K, two dye tests failed at 70 ° C.

It is also interesting to see in Figure 3 how the 50/50 loads of the 30K 100K and 3K10K sections perform well. It can be concluded from these test results that the activity of high molecular weight lignin is much higher than the previous assessment and the low molecular weight fraction does not precipitate in the staining method.

Example 2

This example applies a dye dispersant with four dyes having different hydrophobicity and hydrophilicity (Disperse Orange 30, Disperse Blue 79: 1, Disperse Red 167: 1 and Disperse Blue 60) and the relationship between the various molecular weight portions of Reax ^R 85A. Refers to the thermal stability of lignin. Reax ^R 85A is a sodium sulfate lignin prepared by sulfonating recovered lignin in kraft wood pulp and is widely marketed worldwide as a dye dispersant by Westvaco Corporation. The amount change of Reax ^R 85A was successfully removed from Amicon ultrafiltration vessels using 50K, 10K, 3K, 1K and 500 molecular weight disc membranes under 60 psi of nitrogen. The percentage of low molecular weight material was removed and the sulfonation of the residual portion is shown in Table 2.

Amicon membrane Scattering point (g) % Substance removed 500 1.7 9.0 1K 1.6 12.8 3K 1.2 30.0 10K 0.8 38.9 50 K 0.7 47.1

Thermostability measurements of dye dispersant performance of various Reax ^R 85A sections were performed at Werner Mathis from a package of 2 bar vessels over a temperature range from 70 ° C to 130 ° C, increasing to 2 ° C / min at 1L / min flow rate. It was performed under pressure and compared to the thermal stability performance of the unclassified Reax ^R 85A. Such comparison results are shown graphically in FIGS. 4-7.

In Figures 4-7 it was pointed out that the highest temperature stability in four different dyes was obtained when the molecular weight fraction less than 3000 was removed from Reax ^R 85A. The area of the differential pressure (y-axis) indicates thermal stability, and the larger the area, the worse the thermal stability. Table 2 shows the removal of 30% low molecular weight lignin and inorganic salts in the fractionation method. 4-7 also pointed out the limit on how much lignin can be removed before the thermal stability improvement drops.

In Figure 8 it can be seen that the addition of the high molecular weight portion with Disperse Orange 30 can be reduced to 40% to 45% and still equals the thermal stability of commercial, ultrafiltered Reax ^R 85A. The addition study using Disperse Orange 30 was not included in FIG. 8 but was performed in two parts, 3K and 10K, and the results of the two parts were the same.

Disperse Red 167: 1, Disperse Blue 79: 1 and Disperse Blue 60 (Figs. 9-11, respectively), except that the same trend can be further reduced to 70%, 50% and 80%, respectively. ) Was shown. (Disperse Red 167: 1 and Disperse Blue 79: 1 are hydrophobic dyes, while Disperse Blue 60 is more hydrophilic in nature.) The lower the dispersion addition, the more complete the dyeing process. There was a benefit that the amount of relatively biodegradable lignin needed was smaller.

Example 3

By lignin dye dispersant mixture of the present invention, and commercially Reax ^R 85A and the molecular weight fractionation by ultrafiltration to remove the molecular weight portion of 3,000 or less Reax ^R 85A is the current industry standard, to determine the increase in the supplied dye color Were tested for thermostable boiling to compare their comparative chromaticities. The thermostable boiling test used included 1 g of dye (based on 100%) dispersed in 200 ml of distilled water. pH was adjusted to 4.5 with dilute acetic acid. The dispersion was then heated to 100 ° C. (boiling) and held at 100 ° C. for 15 minutes. The heated dispersion was filtered through a pre-weighted 11 cm Whatman # 2 filter paper placed on top of Whatman # 4 filtration under 22 inch vacuum. The evaluation was based on the amount remaining in the # 2 filter paper.

The results are shown in Table 3.

Dye form Chromaticity (%) of standard Reax ^R 85A Chromaticity (%) of the high Mw Reax 85A Disperse Orange 30 100 175 Disperse Blue 79: 1 200 275 Disperse Red 167: 1 100 200 Disperse Blue 60 200 300 Disperse Red 60 200 264

When the thermal stability boiling test was compared with the improved color scheme (above the current industry standard), all standard Reax ^R 85A formulations failed and all high molecular weight Reax ^R 85A formulations passed the thermal stability test with high color.

Example 4

This example shows an improvement in the thermal stability of the dye mixture obtained by using lignosulfonate dispersants derived from sulfite pulp black liquor from which the low molecular weight portion has been removed. All samples tested were commercial dye dispersants made by Borregaard. The low molecular weight portion of each sample was removed by ultrafiltration as in the previous examples using a molecular weight 3,000 membrane. The measurements obtained are shown in Table 4 below. Molecular weight measurements are average molecular weights; The acid point was determined to be 10 N H ₂ SO ₄ and the last column showed a decrease in the percentage of addition obtained with the same or similar thermal stability.

Sample (Preliminary) yield(%) % Removed MW of reserve 3K MW Reserve AP 3K AP Preliminary Thermal Stability (bar ℃) 3K thermal stability (bar ℃) 3K thermal stability (bar ℃) Ufoxane-rg 49.1 50.9 11,100 13,600 10.1 5.2 58.5 49.9 56.4 (less than 25%) Dynasperse B 38.4 61.6 8,600 12,200 8.7 5.9 69.1 34.9 60.0 (less than 75%) Vanisperse cb 52.1 47.9 3,200 4,200 2.0 1.4 24.4 16.4 16.6 (30% or less)

The thermal stability of the dye mixture was improved to the same addition level, despite the removal of the low molecular weight portion of sulfonated lignin from induced 38.4% to 52.1% of sulfite pulp. Surprisingly, the further reduced additions, which are 25% to 70% lower than the standard addition of preliminary lignin material, led to improved thermal stability values for the dye mixture.

On the other hand it is doubtful that inorganic salts and very low molecular weight lignin portions in the lignin dye dispersant do not precipitate or contribute to the desired dye dispersibility, which is surprising and unexpected. For example, removal of as little as 20% of the lignin dispersion (20% first represented by the low molecular weight portion, i.e. 3K, preferably 10K) results in improved thermal stability of the dye with substantially reduced additions to the dye cake. (Beyond unseparated lignin dye dispersant) leads to an improvement in the obtained product. This recall leads to the following possibilities.

1. The low addition amount will be advantageous from an environmental point of view that a small amount of dispersant enters the wastewater treatment process, making lignin more favorable to the environment; And

2. The low dispersant addition will allow dye preparations of high colority to exceed existing standards. This would be particularly advantageous for liquid preparations that can replace the lowered lignin amount with a dye, thereby increasing the color value of the preparation. The net effect is more effective for packages that improve product throughput and shipping prices for dye factories and inventories in textile mills.

While various, special materials methods, and embodiments herein are described and described with reference to the present invention, it is understood that the invention is not limited to particular materials, combinations and methods selected for that purpose. It was. Many such variants are available, as will be appreciated by those skilled in the art.

Claims (31)

A process for the preparation of an improved dye composition comprising combining a dye cake and a lignin dispersant, wherein the process comprises treating the lignin dispersant to remove a portion of the lignin dispersant having a molecular weight of less than 3,000 before combining with the dye cake. Improved dye composition. The method according to claim 1, wherein the lignin is lignosulfonate recovered from the black liquor from the sulfite woodpulp method. The process according to claim 1, wherein the lignin is recovered from the black liquor from the alkali woodpulp method and subsequently reacted with sodium sulfite and formaldehyde. 4. A method according to claim 3, wherein the alkali woodpulp method is selected from the group consisting of kraft and soda woodpulp processes. The method of claim 1, wherein the dye cake is selected from the group consisting of disperse dyes and vat salt dyes and the lignin dispersant is selected from the group of sulfonated lignin and sulfomethylated lignin. The process of claim 1 wherein the treatment to remove the portion of the lignin dispersant having a molecular weight of less than 3,000 is performed by separating the portion of the dispersant having a molecular weight of less than 3,000 from the remaining portion of the dispersant. Characterized in that it is fractional. 7. The method of claim 6, wherein the fractionation is performed by ultrafiltration of the lignin dispersant through the membrane designed to remove the molecular weight portion of the lignin dispersant of less than 3,000. The method of claim 1, wherein the improvement consists in treating the lignin dispersant to remove a portion of the lignin dispersant having a molecular weight of less than 10,000 prior to combining with the dye cake. 7. The method of claim 6, wherein the fractionation is performed by ultrafiltration of the lignin dispersant through the membrane designed to remove the molecular weight portion of the lignin dispersant of less than 10,000. 7. The process of claim 6, wherein the fractionation is carried out by reversible osmosis of the lignin dispersant for removal of the molecular weight moiety having a molecular weight of less than 3,000. The method of claim 10 wherein the fractionation is carried out by reversible osmosis of the lignin dispersant for removal of the molecular weight moiety having a molecular weight of less than 10,000. 7. The method of claim 6, wherein the fractionation is preceded by crosslinking a portion of the lignin dispersant having a molecular weight of less than 3,000. 13. The process of claim 12, wherein the fractionation is preceded by crosslinking a portion of the lignin dispersant having a molecular weight of less than 10,000. A process for preparing a dye mixture consisting of a dye cake and a lignin dispersant selected from the group of sulfonated lignins and sulfomethylated lignin, wherein the lignin dispersant recovers the lignin material from the black liquor from the alkali woodpulp method and has a molecular weight of less than 3,000. Treating the residual lignin with sodium sulfite and formaldehyde. 15. The method of claim 14, wherein the alkali woodpulp method is a member of a group consisting of soda and kraft pulp methods. 15. The method of claim 14, wherein the dye cake is selected from the group consisting of disperse dyes and vat dyes. 15. The process of claim 14 wherein the treatment for removal of the recovered lignin moiety having a molecular weight of less than 3,000 fractionates the recovered lignin according to its molecular weight to separate the lignin moiety having a molecular weight of less than 3,000 from the remaining portion of lignin. Characterized in that. 18. The process of claim 17, wherein the fractionation is performed by ultrafiltration of recovered lignin through a membrane designed to remove the molecular weight portion of recovered lignin with a molecular weight less than 3,000. 15. The method of claim 14, wherein the improvement comprises treating the recovered lignin to remove a portion of the recovered lignin having a molecular weight of less than 10,000 prior to reacting the lignin dispersant with sodium sulfite to formaldehyde. 18. The method of claim 17, wherein the fractionation is performed by ultrafiltration of the lignin dispersant through a membrane designed to remove less than 10,000 molecular weight portions of the lignin dispersant. 18. The process of claim 17, wherein the fractionation is performed by reversible osmosis of the recovered lignin for removal of the recovered lignin molecular weight portion of less than 3,000 molecular weight. 22. The method of claim 21, wherein the fractionation is performed by reversible osmosis of the recovered lignin for removal of the recovered lignin molecular weight portion of less than 10,000 molecular weight. 18. The method of claim 17, wherein the fractionation is preceded by crosslinking a portion of the recovered lignin having a molecular weight of less than 3,000. 24. The method of claim 23, wherein the fractionation is preceded by crosslinking a portion of the recovered lignin having a molecular weight of less than 10,000. An improved lignin dye dispersant selected from the group consisting of sulfonated lignin and sulfomethylated lignin, wherein the lignin dispersant is essentially free of molecules of less than 3,000 molecular weight. A dye mixture consisting of a combination of a dye cake and a lignin dispersant, wherein the lignin dispersant is selected from the group consisting of sulfonated lignin and sulfomethylated lignin and is essentially free of molecules having a molecular weight of less than 3,000. 27. The dye mixture of claim 26, wherein the lignin is recovered from a woodpulp method selected from the group of sulfite and alkali woodpulp methods. 28. The dye mixture of claim 27, wherein the lignin is recovered from an alkali woodpulp method selected from kraft pulp and soda methods. 29. The dye mixture of claim 28, wherein the dye cake is selected from the group of disperse dyes and dry salt dyes. 30. The dye mixture of claim 29, wherein the dye cake is a disperse dye. 29. The dye mixture of claim 28, wherein the lignin dispersant is essentially free of molecules having a molecular weight of less than 10,000.