WO2006068977A2

WO2006068977A2 - Storage stable, concentrated, copper containing liquid dye solutions

Info

Publication number: WO2006068977A2
Application number: PCT/US2005/045765
Authority: WO
Inventors: Howard H. Joyner; Richard H. Kokel; Michelle M. Coker
Original assignee: Kemira Oyj
Priority date: 2004-12-22
Filing date: 2005-12-16
Publication date: 2006-06-29
Also published as: TW200710178A; WO2006068977A3

Abstract

The invention relates to a composition comprising a storage, stable liquid dye having a formula (I) wherein M+ is an alkali metal; and wherein the dye is a storage stable liquid. The invention also relates to methods for making the dye, methods for using the dye, and paper products made with the dye.

Description

ggbftWdK -gnsMaaiE. CONCENTRATED, COPPER CONTAINING

STORAGE STABLE. LIQUID DYES

FIELD OF INVENTION

The present invention relates to stable, concentrated aqueous formulations of copper-containing direct dyes and the unique process for their preparation. More particularly, the invention relates to concentrated liquid direct dye formulations that color cellulosic fiber in bright light-fast reddish blue shades.

BACKGROUND

There remains a demand in the paper and printing markets for dyes that are distinguished by highly brilliant reddish blue shades, with high substantivity, and exceptional lightfastness in a convenient liquid form. Historically, there have been few commercial liquid dyes that possess the attractive aforementioned properties. The dyes described in prior art intended for cellulosic fibers, e.g. paper, are limited for example to Colour Index (herinafter referred to as C.I.) Direct Blue 290 (hereinafter referred to as for example, C.I. Direct Blue 290 or Direct Blue 290) and C.I. Direct Blue 273. C.I. Direct Blue 290 is an attractive blue dye with high lightfastness but is lengthy in its preparation and therefore imparts higher manufacturing costs. C.I. Direct Blue 273 is greener and duller in shade as compared to C.I. Direct Blue 290. It is the object of this invention to devise a dye with properties equivalent to or superior to C.I. Direct Blue 273 or C.I. Direct Blue 290 as well as one that is cost effective to prepare. C.I. Direct Blue 80 is a dye that exhibits a brilliant red-blue shade and exceptional substantivity and lightfastness. C.I. Direct Blue 80 can also be utilized with other dyestuffs, such as yellows, reds and violets to name some, that allow the production of a wide array of colored substrates. Although powder versions of this dye are known, stable liquid versions of C.I. Direct Blue 80 are not commercially available.

The use of commercially concentrated liquid dyes offers several advantages over available powder dyes. For instance, powder dyes readily •crfe&te 'aust, ¹WiIiCn makθs an unpleasant, and potentially hazardous work environment. Liquid dyes are much easier to measure and are overall easier to handle than powder dyes. Powder dyes are difficult to continuously meter into a user's end process, whereas liquid dyes are easily measured in continuous dyeing processes. Another advantage of concentrated liquid dye formulations over powders is that it frees the dye user from the time consuming task of dissolving the dye powder in aqueous media. Dissolving powder dyes also carriers the risk of incomplete dissolution and can result in dye particles that can plug filters, and/or exhibit themselves in the finished substrate as undesirable colored specks.

GB 2,079,327 discloses that it is not possible to prepare certain copper-containing diazo dyes in their alkali metal forms as a liquid in concentrations of more than a few percent by weight. The patent also does not discuss the making of dyes in an ammonium salt form.

SUMMARY

The invention relates to a composition comprising a storage stable, liquid dye having a formula:

wherein M+ is an alkali metal; and wherein the dye is a storage stable liquid.

In another embodiment, the invention relates to a process comprising: flji^: αiazotrziragj!: 3,3'-dimethoxybenzidine under conditions that produce a tetrazonium salt;

(b) reacting the tetrazonium salt to 2-hydroxynaphthalene-3,6- disulfonic acid under conditions that form a bis-azo compound;

(c) reacting the bis-azo compound in an aqueous environment with a copper donor under conditions that produce forming a copper- containing dye having a formula:

wherein M+ is an alkali metal; and

(d) desalinating the copper-containing dye with a cross-flow membrane; wherein the metallized dye is not isolated as a solid; and wherein the dye is a storage stable liquid.

In another embodiment, the invention relates to a process comprising treating a paper substrate with a composition comprising a storage stable, liquid dye having a formula:

wherein M+ is an alkali metal; and wrϊβreϊrtiffie dyeius;a storage stable liquid.

The invention also relates to paper made with the above-mentioned dye.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.

DESCRIPTION

The invention is based on the discovery that it is now feasible to prepare a storage stable, liquid dye of a copper-containing dye in the form of an alkali salt, e.g. sodium, in relatively high concentrations, e.g., more than 9 % by weight. The invention is also based on the finding that it is achievable to synthesize a storage stable, concentrated liquid dye without isolation of the dye at any point during the synthesis. The discovery also pertains to the practicality of scale of reaction. The storage, stable liquid dye can be prepared in large commercial quantities (~20,000 kg) in relatively high rates of production.

The term "storage stable," as it is used herein, refers to the dye of this invention being in a homogenous liquid form and readily useful for its intended application for a period of at least one month, or longer, e.g., at least six months and preferably at least twelve months, or more.

Other than in the operating examples or where otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as modified in all instances by the term "about." Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

The invention relates to a storage stable, liquid dye having a formula:

wherein M+ is an alkali metal; and wherein the dye is a storage stable liquid. A powdered version of this dye is known as C.I. Direct Blue 80. Prior to this invention, however, storage stable liquid versions of this dye in their alkali metal form have not been available and have not been known to exist.

The aqueous storage stable, liquid dye has sufficient solids content such that when it is used in accordance to the invention, the resulting composition imparts a brilliant, reddish blue hue with very good lightfastness to paper. In one embodiment, the storage stable, liquid dye has a solids content ranging from 9 or 12 to 20 wt% solids (or more than 20 wt%).

The storage stable liquid dye composition of the invention has an alkali metal salt content that is sufficiently low to make the composition liquid and storage stable. It is well known that relatively high levels of alkali salts prevent the formation of a concentrated, storage stable liquid dye. The composition of this invention, however, advantageously avoids such problems. The alkali metal salt content is generally below 3 wt%. In another embodiment, the alkali metal salt content is less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%. In one embodiment, the composition has an alkali metal salt content that is less than 0.5 wt% and a dye solids content that is more than 9 wt%.

Alkali metals include ammonium, sodium, potassium, lithium, rubidium, cesium, francium. Due to high cost and handling procedures, rubidium, cesium, francium are not useful for commercial applications. SP .s'tδMgβ¹" BdBe, liquid dye is storage stable at a room temperature (25⁰C) for extended periods of time. In one embodiment, the liquid dye is storage stable for at least one month. In another embodiment, the liquid dye is storage stable for at least six months, or for at least one year or more.

The storage stable, liquid dye can contain additional components. For applications in which it is useful to have extended shelf life, the liquid dye can be mixed with a solvent in which is compatible with the aqueous dye. Examples of suitable solvents include ethoxylated N-alkanolamines, e.g., ethoxylated triethanolamine, or triethanolamine, diethanolamine. The solvent is present in an amount that is sufficient so as to impart to the resulting liquid dye acceptable storage stability properties. Without being bound by theory, it is believed that the ethoxylated triethanolamine improves the storage stability at temperatures less than 5OT (10°C). The specific amounts will vary, depending on application. Suitable amounts, for instance, can range from 0.1 to 10 or 15 wt%, or from 5 to 7 wt%.

In another component, the composition further contains a biocide. Examples of suitable biocides include and are not limited to imidacloprid, tebuconazole, and 2,6-dimethyl-m-dioxan-4-ol acetate. 2,6-dimethyl-m- dioxan-4-ol acetate can be obtained from Dow Chemical under the trademark BIOBAN™ DXN. Imidacloprid and tebuconazole may be obtained from LANXESS Corporation, Pittsburgh, PA. Also suitable are those biocides sold under the trademarks Proxel GXL and BULAB 6057. The specific amounts will vary, depending on application. Suitable amounts, for instance, can range from 0.1 to 5, or from 1 to 2 wt%.

The invention provides a method for preparing a concentrated, storage stable C.I. Direct Blue 80 liquid dye that generally involves the steps of:

(a) diazotizing 3,3'-dimethoxybenzidine under conditions that produce a tetrazonium salt;

(b) reacting the tetrazonium salt to 2-hydroxynaphthalene-3,6- disulfonic acid under conditions that form a bis-azo compound; (d) reaefln'g'WiS⁶ bis-azo compound in an aqueous environment with a copper donor under conditions that produce forming a copper- containing dye having a formula:

wherein M+ is an alkali metal; and

(d) desalinating the copper-containing dye with a cross-flow membrane; such that the metallized dye is not isolated as a solid (preferably never isolated as a solid), and where the dye is a storage stable liquid.

The step of diazotizing 3,3'-dimethoxybenzidine dihydrochloride is generally affected with nitrous acid in aqueous-mineral acid solution at low temperatures. The pH of this reaction is generally 3 or less. The temperature at which the diazotization reaction is carried out is generally at least 10⁰C. In one embodiment, the temperature is from 10 to 20 "C. In one embodiment, the temperature is from 13 to 17°C.

The step of reacting (coupling) tetrazonium salt to 2- hydroxynaphthalene-3,6-disulfonic acid under conditions to forming a bis- azo compound generally involves subjecting the aqueous bis-azo intermediate to conditions that utilize a suitable copper donor such as copper sulfate pentahydrate that produce a copper-containing dye. The coupling reaction is carried out under weakly alkaline to alkaline conditions. In one embodiment, the pH ranges from 7 to 10. In one embodiment, the pH ranges from 8 to 9.5.

The reaction with the copper donor can be carried out with ammonia, pyridine, morpholine, ethanolamine, diethanolamine, triethanol- άMtify

N,N-dimethylethanolamine, N- methylethanolamine, N.N-dimethylisopropanolamine, N,N-diethylisopro- panolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, propanolamine, and combinations thereof.

The reaction conditions and reaction times vary with each amine used. Suitable copper donors are salts which contain copper as cation, e.g., copper sulfate, copper chloride or copper acetate. It is often advantageous to use complex copper compounds, e.g., in the form of copper- amine complexes such as copper tetraamine sulfate obtained from copper sulfate and ammonia, pyridine or monoethanolamine, or in the form of compounds which contain copper bound as a complex, e.g. complex compound of alkali salts of aliphatic aminocarboxylic acids or hydroxycarboxylic acids, e.g. glycocoll, lactic acid and, in particular, tartaric acid, e.g. sodium copper tartrate.

The treatment with the copper donor is carried out in aqueous or organic-aqueous medium, e.g., at room temperature if readily metallizable compounds are used as starting materials, or by heating to a temperature in the range from 50 to 120°C in a closed vessel under pressure, whilst the pH values are determined by the nature of the chosen method of metallization: for example, an acid coppering with copper sulfate, and in alkaline coppering with copper tetraamine sulfate. If desired, it is possible to add solvents, e.g., alcohol, dimethylformamide, and the like during the metallization. In one embodiment, the bis-azo compound is metallized with a compound selected from the group consisting of diethanolamine, triethanolamine, ammonia, pyridine, morpholine, ethanolamine, N₁N- diethyldiethanolamine, N,N-dimethylethanolamine, N-methylethanolamine, N,N-dimethylisopropanolamine,N,N-diethylisopropanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, propanolamine and combinations thereof.

The step of desalinating the metallized dye with cross-flow membrane technology generally involves subjecting the metallized dye to ■a 'imeπiϋrane "of":-tne ^appropriate type and diafiltering the product with deionized water to remove salts.

Depending on how the process is carried out, the final product can contain residual amounts of alkanolamine and inorganic salts.

The process enables the production of a storage stable liquid Direct Blue 80 in concentrations exceeding 9% by weight without the need to isolate the dyestuff. This is an extremely valuable advantage over known processes requiring the isolation of the dyestuff-a process that is laborious and time consuming.

Advantageously, the process for making the liquid direct blue 80 produces dye in large amounts. In one embodiment, the invention provides a process in which the dye is produced in a batch process at an amount that is at least 1000 lbs (454 kg) over a 48 hour period. In another embodiment, the process produces at least 10,000 (4545 kg) of direct liquid dye. In another embodiment, the process produces at least 40,000 lbs (18,181 kg) during a 48 hour period. In one embodiment, the process can produce from 1000 lbs (454 kg) to 50,000 lbs (22,727 kg) of the dye during a 48 hour period.

The process can be altered by routine modification and an ordinary skilled artisan will recognize variations. In one embodiment, 3,3'- dimethoxybenzidine dihydrochloride is diazotized using sodium nitrite in aqueous hydrochloric acid to form a tetrazonium salt. This tetrazonium salt can be cooled to O⁰C and reacted with 2-hydroxynaphthalene-3,6- disulfonic acid at a pH value of 8 to 9.5. The resulting bis-azo compound is copperized in an aqueous solution with copper sulfate and a suitable alkanolamine by heating to reflux. The copper-containing dye is then desalinated using cross-flow membrane technology to produce a liquid dye with minimal ionic content. In another embodiment, where sodium nitrite is used, o-Dianisidine Dihydrochloride is directly diazotized using sodium nitrite in aqueous hydrochloric acid to form a bis-diazonium salt. This diazonium salt is cooled to O⁰C and coupled to R salt at a pH value of 8 to 9.5. The resulting bisdiazo dyestuff is metallized in an aqueous solution witW '¹OOpP¹Br .'Sαtfaie/afocfta suitable alkanolamine by heating to reflux for several hours. The metallized dye is desalinated using cross-flow membrane technology to produce a liquid dye with minimal ionic content.

In use, the invention provides novel methods of using a convenient liquid version of the dye such that the dye has high and rapid affinity for the cellulosic fiber, and is colored to the cellulosic fiber in a brilliant reddish-blue shade and dyed fiber possesses very good fastness properties, especially with regard to lightfastness. The dye colors paper in a bright reddish blue shade of high fastness properties, especially with respect to substantivity and lightfastness.

In one embodiment, the invention relates to a process that involves treating a paper substrate with a composition comprising the liquid dye having a formula:

such that M+ is an alkali metal; and the dye is a storage stable liquid.

In one embodiment, the invention provides a process that involves treating cellulosic fiber with an aqueous liquid dye containing an alkali metal salt form of C.I. Direct Blue 80 and thereby forming a paper having a brilliant reddish blue color and very good lightfastness. An in another embodiment, the invention relates to paper made from the dyeing process.

The liquid dye of the invention can be applied to a wide variety of substrates. For paper substrates, for instance, the paper can be any fibrous substrate, which when treated with the liquid dye, produces attractive blue shades and useful lighfastness properties.

As such, the invention provides previously unavailable advantages. While powder versions of this copperized dye with the above mentioned properties are known, commercially available stable liquid versions of C.I. ^■DirøCt¹ Blue βϋ'a/fe nM::kh^"©wn to exist. The advantages of the liquid dye of the invention these dyes over powder versions are lack of dusting, ease of measurement, ability to be continuously metered to a customer's end process, and overall ease of use.

The invention is further described in the following illustrative examples in which all parts and percentages are by weight unless otherwise indicated.

EXAMPLE 1

24.4 parts of 3,3'-dimethoxybenzidine dihydrochloride was diazotized and the tetrazo compound subsequently obtained coupled to 73.7 parts of 2-hydroxynaphthalene-3, 6-disulfonic acid at a pH value of 8.5 to 9.5 by addition of sodium carbonate. To the suspension of the resultant bisazo dye was added 37.4 parts 31% hydrochloric acid solution and the mixture allowed to stir for 2 hours after the addition was complete. To this aqueous suspension was added 8 parts 29% ammonia and the mixture heated to 40°C. 99.8 parts diethanolamine were added and the reaction mixture additionally heated to 50°C. 52.3 parts of copper sulfate pentahydrate were added over the course of 30 minutes and the deep blue solution brought to reflux. The reaction solution was kept under strong reflux for a period of 12 hours. The resultant coppered dyestuff was cooled to 45°C and subjected to ultra-filtration in a conventional ultra-filtration system. After 3 reaction volumes were exchanged with deionized water the volume was reduced to ca. 45% of the original volume. 87.1 parts of ethoxylated amine were charged to the dye solution along with a small amount of biocide. After adding a ca. 40 parts of water, there was obtained 871 parts of a storage stable dye formulation as the sodium salt containing less than 0.5% of residual inorganic salts and a dye content of 10.6% by weight (calculated as the sodium salt). This dye solution is suitable for dyeing paper to produce a brilliant reddish-blue shade. EXAMPLE 2

The procedure of Example 1 is repeated substantially as described with the exception that a combination of lithium carbonate and lithium hydroxide monohydrate are employed in place of sodium carbonate respectively. A storage stable dye formulation is prepared as the lithium salt and contains less than 0.5% residual inorganic salts and a dye content of 10.3% by weight (calculated as the lithium salt).

EXAMPLE 3

The procedure of Example 1 is repeated substantially as described with the exception that a combination of potassium carbonate and potassium hydroxide are employed in place of sodium carbonate respectively. A storage stable dye formulation is prepared as the potassium salt and contains less than 0.5% residual inorganic salts and a dye content of 10.9% by weight (calculated as the potassium salt).

EXAMPLE 4

The procedure of Example 1 is repeated substantially as described with the exception that a combination of ammonium carbonate and ammonium hydroxide are employed in place of sodium carbonate respectively. A storage stable dye formulation is prepared as the ammonium salt and contains less than 0.5% residual inorganic salts and a dye content of 10.5% by weight (calculated as the ammonium salt).

Although the present invention has been described in detail with reference to certain preferred versions thereof, other variations are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the versions contained therein.

Claims

WHAT IS CLAIMED IS

1. A composition comprising a liquid dye having a formula:

wherein M+ is an alkali metal; and wherein the dye is a storage stable liquid.

2. The composition of Claim 1, wherein the composition has a residual inorganic salt content that is less than 0.5 wt% and a dye solids content that is more than 9 wt%.

3. The composition of Claim 1 , wherein the composition further comprises an ethoxylated N-alkanolamine.

4. The composition of Claim 1 , wherein the composition further comprises a biocide.

5. The composition of Claim 3, wherein the biocide is selected from the group consisting of imidacloprid, tebucanozole, 2,6-dimethyl-m- dioxan-4 -ol acetate, and combinations thereof.

6. The composition of Claim 1 , wherein the composition has a solids content ranging from 9 to 20 wt%.

7. The composition of Claim 1, wherein the composition is a storage stable liquid at room temperature for at least one month.

8. The composition of Claim 1 , wherein the composition is a storage stable liquid at room temperature for at least six months. i§3 T^eSciMpβsition of Claim 1, wherein the alkali metal is selected from the group consisting of lithium, potassium, sodium, ammonium, and combinations thereof.

10. A process comprising:

(c) reacting the bis-azo compound in an aqueous environment with a copper donor under conditions that produce forming a copper- containing dye having a formula.

wherein M+ is an alkali metal; and

11. The process of Claim 10, wherein the metallized dye is never isolated as a solid.

12. The process of Claim 10, wherein 3,3'-dimethoxybenzidine is diazotized through the use of nitrous acid in an aqueous mineral acid solution.

13. The process of Claim 10, wherein the bis-azo compound is treated with a compound selected from the group consisting of ammonia, ■øyΗϊ-ta&J fiorplhb'Wne', ⁽ettϋinolamine, diethanolamine, triethanolamine, N₁N- diethyldiethanolamine, N.N-dimethylethanolamine, N-methyldiethanol- amine, N-methylethanolamine, N,N-dimethylisopropanolamine, N₁N- diethylisopropanolamine, isopropanolamine, diisopropanolamine, triiso- propanolamine, propanolamine, and combinations thereof.

14. The process of Claim 10, wherein the diazonium salt is cooled to O⁰C.

15. The process of Claim 10, wherein the coupling step of step(c) is carried out a pH ranging from 8 to 9.5.

16. The process of Claim 10, wherein the bis-azo compound is copperized by heating to reflux.

17. The process of Claim 10₁ wherein at least 454 kg of the dye is produced in a batch process during a 48 hour period.

18. A process comprising treating a paper substrate with a composition comprising a liquid dye having a formula:

wherein M+ is an alkali metal; and wherein the dye is a storage stable liquid.

19. The process of Claim 18, wherein the composition has a residual inorganic salt content that is less than 0.5 wt% and a dye solids content that is more than 9 wt%.

20. The process of Claim 18, wherein the composition further comprises an ethoxylated N-alkanolamine.

21. The process of Claim 18, wherein the composition further comprises a biocide. iϋi MeEp7oϊie§s of Claim 18, wherein the biocide is selected from the group consisting of imidacloprid, tebucanozole, 2,6-dimethyl-m- dioxan-4 -ol acetate, and combinations thereof.

23. The process of Claim 18, wherein the composition has a solids content ranging from 9 to 20 wt%.

24. The process of Claim 18, wherein the composition is a storage stable liquid at room temperature for at least one month.

25. The process of Claim 18, wherein the composition is a storage stable liquid at room temperature for at least six months.

26. The process of Claim 18, wherein the alkali metal salt cation is selected from the group consisting of lithium, potassium, sodium, ammonium, and combinations thereof.

27. A paper made with the process of Claim 18.