GB2234977A

GB2234977A - Water-soluble dyestuffs suitable for use in inks

Info

Publication number: GB2234977A
Application number: GB9016136A
Authority: GB
Inventors: Anthony J Murrells; Peter Jackon
Original assignee: Berol Ltd
Current assignee: Berol Ltd
Priority date: 1989-07-25
Filing date: 1990-07-23
Publication date: 1991-02-20
Anticipated expiration: 2010-07-23
Also published as: GB2234977B; GB9016136D0; GB8916941D0

Abstract

Water-soluble dyestuffs suitable for use in inks employable in writing instruments or markers are obtained by reacting a reactive dyestuff (A), for example a vinyl sulphone reactive dyestuff, with a water-soluble polymer or resin component (B) chosen from polyethylene glycols, starches, gum arabic, polyalkylene oxides, polyvinylpyrrolidone, glycol ethers and hydroxyl terminated surfactants.

Description

TITLE Improvements in or relating to Water-soluble Dvestuffs Suitable as Inks The present invention relates to water-soluble dyestuffs suitable for inks, especially for pens and markers, for instance for children's use.

The invention seeks to provide water based inks for pens and markers that are washable by normal domestic washing techniques. Currently water based inks used for writing and marking are based upon dyestuffs and pigments that are in the main intractable to the usual methods of washing and very often cannot be removed without severe treatments that are very often detrimental to the article concerned whether it be clothing, furniture, leather goods, etc.

There are two methods known to us which give variable results. Firstly it is known that dyestuffs are produced where part of the dye molecule is rendered water soluble by the addition of long chain alkylenoxy units. This is achieved by the addition of ethylene oxide to the dye precursor. The precursor is then reacted to give a modified azo dyestuff. (U.S. Patent specification 4 167 510).

The second method involves the selection of suitable dyes; the selection is usually taken from existing acid dyes that have little affinity for fabrics.

The disadvantage of the first method is that it involves sophisticated production equipment capable of handling toxic ethylene oxide and is limited at the moment to the production of modified azo dyes. The second method has the disadvantages of poor washability from cotton/linen type fabrics and the available dyes tend to stain the skin.

There have been available for many years reactive dyestuffs which are used for the purpose of creating highly permanent dyeings of natural fabrics based upon cellulose. The novelty of the current invention is to react these dyes with a variety of water soluble polymeric materials so as to produce a high molecular weight, water soluble product that is capable of washing completely from clothes and skin. In addition the whole range of dye chromophores as used in reactive dyes are available for use as part of the invention. An ink that is formulated from these reacted dyes may be used as part of an ink formula for writing instruments, markers and any other process of using water soluble dyes that are required to continue to exhibit water solubility with little in the way of subsantivity towards fabrics and skin, for example paints used by children in play or education.

According to one aspect of the invention there is provided a water-soluble dyestuff which has been obtained by reacting a reactive dyestuff (A) with a water-soluble polymer or resin component (B), the component (B) being chosen from polyalkylene glycols, preferably polyethylene glycols such as diethylene glycol and triethylene glycol, starches, gum arabic, polyalkylene oxides, preferably polyethylene oxides, polyvinylpyrrolidone, glycol ethers and hydroxyl terminated surfactants.

As component (B) there may be used polyethylene oxides ranging in molecular weight from for example 200 to 10000, preferably 600 to 1500. For example, the polyethylene oxides used may be those depicted by the general formula HO - (CH2 - CH2)n - OH wherein n is an integer ranging from 3 to 160.

As component (A) there may be used various reactive dyestuffs. For example, there may be used a vinyl sulphone reactive dyestuff (available from Hoechst), a mono-chlor-triazinyl or a di-chlor-triazinyl reactive dyestuff (available from I. C. I.) or a di-chlor-pyrimidyl or tri-chlor-pyrimidyl reactive dyestuff (available from Ciba Geigy).

In this invention the term reactive dyestuff" is intended to mean a reactive dyestuff consisting of a dyestuff moiety and a reactive linkage. For example, dyestuff - SO2 - CH2 - CH2 - S03 Na (dyestuff - reactive linkage) An equation for a vinyl sulphone type of reaction (nucleophilic addition) is suggested to be dyestuff - SO2 - CH2 - CH20 - S03 Na

dyestuff

SO - CH = CH2 + Na2SO4 + H2O OH - polymeric moiety dyestuff - 302 - CH2 - CH2 - 0 - polymeric moiety The following reactive groups have been used in commercial ranges of dyestuffs either singly or in combination within the same dye molecule.The list is not intended to be exhaustive as any reactive dyestuff that is capable of reacting under the conditions specified, i.e. typically those for reactive dyes, will produce a product that may have utility as a washable ink.

Mono-chloro-triaz inyl.

Di-chloro-triaz inyl.

2,4-Di-chloro-pyrimidinyl 2,4, 5-Tri-chloro-pyrimidinyl 2,3-Di-chloro-quinoxaline-6-carbonyl.

4,5-Di-chloro--6--pyridazonylpropionyl.

1, 4-Di-chlorophthalazine-6-carbonyl.

Chlorobenzothiazole. (linked to the dye molecule via -CONH-, -S02 NH-, -NH- or -N=N-.) 5-Chloro-4-methyl-2-methylsulphonylpyrimidinyl Vinylsulphonyl B-Sulphatoethylsulphonyl.

B-Sulphatoethylaminosulphonyl.

B-Chlorethylsulphonyl.

B-Sulphatopropionamido.

For the purposes of the present invention it is an advantage if the dyestuff used in the invention is dischargeable, i.e. capable of being bleached by chemicals other than domestic bleach, to a white ground.

This allows for the possibility of the water-soluble dyestuff being removed from surfaces that is is not possible to wash (e.g. wallpapers).

According to another aspect of the invention there is provided a process for producing a water-soluble dyestuff comprising dissolving a component (B) as defined above in an aqueous solvent, adding thereto a reactive dyestuff (A) and adjusting the pH up to a value of 9.0 to 12.0 with a suitable base e.g. sodium hydroxide, sodium carbonate and sodium bicarbonate,, heating to complete the reaction and thereafter cooling and adjusting the pH to 5 - 7. The dyestuff so produced may then be formulated into a water-soluble ink by addition of suitable additives known per se.

According to a third aspect of the invention there is provided a process for producing a water-soluble dyestuff comprising dissolving a component (B) as defined above in an aqueous solvent and adding thereto a reactive dyestuff (A) at ambient temperature at a pH of 7-10 and allowing the reaction to proceed over a prolonged period, for example, more than a week.

According to a fourth aspect of the invention there is provided use of the water-soluble dyestuff of the invention as ink.

According to a fifth aspect of the invention there is provided a writing instrument or marker utilising as ink the water-soluble dyestuff of the invention.

EXAMPLES Examle 1 5 parts by weight of a vinyl sulphone reactive dyestuff (supplied by Hoechst) are mixed well with half 77 parts by weight) at room temperature to produce a solution. The solution is then filtered to remove any insoluble materials. The rest of the water is charged into a reaction vessel fitted with means of heating, cooling, temperature control, pH measurement and vigorous stirring. To the water in the reaction vessel is added 15 parts by weight of solid polyethylene glycol having a molecular weight of 1000. The temperature is raised with stirring to dissolve the glycol (45 degrees Celsius). At this stage the dyestuff solution is added and the temperature is raised to 900 Celsius. At this temperature .3 parts by weight of 4 molar caustic soda solution are added. The pH at this stage should be between 10.5 and 11.0. The temperature is maintained at 900 Celsius for ten minutes with stirring and then the reaction is cooled at 45O Celsius. At this stage the pH is adjusted with either concentrated hydrochloric acid or acetic acid to 6 - 7. This inhibits any further reaction between the dyestuff and the ethylene glycol.

The resultant water-soluble dyestuff is suitable as a water-soluble ink and it is then adjusted for surface tension with a surfactant and a preservative is added to prevent microbiological spoilage.

Example 2 10 parts by weight of polyethylene glycol of average molecular weight 1000 are added to 40 parts by weight of deionised water in a reaction vessel. The temperature of the water is raised to 80 degrees Celsius during which time the polyethylene glycol dissolves. When the water is at temperature 5 parts by weight of a vinyl sulphone reactive dyestuff (supplied by Hoechst) are added thereto with stirring followed by 1.5 parts by weight of sodium bicarbonate. The pH at this time should be in a range of 10 - 11. The pH may be adjusted upward if required by the addition of more bicarbonate. The temperature of the water is maintained at 80 degrees Celsius for one hour following which 10 parts by weight of glycerine are added thereto.

The addition of glycerine is beneficial for inhibiting any tendency for formation subsequently of a gel structure following the reaction between the dyestuff and the glycol.

30 parts by weight of water are then added thereto to reduce the temperature and the reaction vessel is cooled to ambient temperature. During the cooling phase the pH of the reaction mixture is lowered to a range of pH 5.0 to 6.0 with hydrochloric acid. The resultant water-soluble dyestuff is suitable as a uater-soluble ink and it is then adjusted for surface tension with a surfactant and a preservative is added to prevent microbiological spoilage.

Claims

1. A water-soluble dyestuff which has been obtained by reacting a reactive dyestuff.(A) with a water-soluble polymer or resin component (B), the component (B) being chosen from polyethylene glycols, starches, gum arabic, polyalkylene oxides, polyvinylpyrrolidone, glycol ethers and hydroxyl terminated surfactants.

2. A water-soluble dyestuff according to Claim 1, wherein component (B) is chosen from diethylene glycol and triethylene glycol.

3. A water-soluble dyestuff according to Claim 1, wherein component (B) is chosen from polyethylene oxides ranging in molecular weight from 200 to 10,000.

4. A water-soluble dyestuff according to Claim 3, wherein the polyethylene oxides range from 600 to 15,000.

5. A water-soluble dyestuff according to Claim 1, wherein component (B) is chosen from polyethylene oxides depicted by the general formula HO -(CH2 -CH2)n -OH wherein n is an integer ranging from 3 to 160.

6. A water-soluble dyestuff according to any preceding claim, wherein the reactive dyestuff (A) is chosen from a vinyl sulphone reactive dyestuff, a mono-chlortriazinyl or a di-chlor-triazinyl reactive dyestuff or a di-chlor-pyrimidyl or tri-chlor-pyrimidyl reactive dyestuff.

7. A water-soluble dyestuff according to any preceding claim, which is dischargeable to a white ground.

8. A water-soluble dyestuff according to Claim 1 substantially as herein described and exemplified.

9. A process for producing a water-soluble dyestuff comprising dissolving a component (B) as defined in Claim 1 in an aqueous solvent, adding thereto a reactive dyestuff (A) and adjusting the pH to a value of 9.0 to 12.0 with a suitable base, heating to complete the reaction and thereafter cooling and adjusting the pH to 5 - 7.

10. A process according to Claim 9, wherein the base is chosen from sodium hydroxide, sodium carbonate and sodium bicarbonate.

11. A process according to Claim 9 substantially as herein described.

12. A process for producing a water-soluble dyestuffcomprising dissolving a component (B) as defined in Claim 1 in an aqueous solvent and adding thereto a reactive dyestuff at ambient temperature at a pH of 7-10 and allowing the reaction to proceed over a prolonged period.

13. A process according to Claim 12, wherein the prolonged period is more than a week.

14. Use of the water-soluble dyestuff as claimed in any one of Claims 1 to 8 as ink.

15. A writing instrument or marker utilising as ink the water-soluble dyestuff claimed in any one of Claims 1 to 8.