GB1603100A - Dispersing agents based on water soluble phenolic condensates - Google Patents

Description

(54) DISPERSING AGENTS BASED ON MODIFIED WATER SOLUBLE PHENOLIC CONDENSATES (71) We, YORKSHIRE CHEMICALS LIMITED, a British company of Black Bull Street, Leeds, LS10 1HP. do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to aqueous dispersion preparations or powder preparations of water-insoluble or sparingly soluble dyes, especially disperse dyes.

Condensation products of naphthalene mono-sulphonic acids, or of the mono-sulphonic acids of phenol and/or other phenolic compounds with formaldehyde are well-known as dispersing agents, and those derived from naphthalene mono-sulphonic acids have been very widely used. The various commercial grades of sodium lignosulphonate have also found extensive use for this purpose. These products have been used for many years for the preparation of dispersions of such water-insoluble or sparingly soluble substances as pigments, clays, certain agricultural chemicals and in particular, disperse dyes. Many excellent dispersions of disperse dyes have been made using these well-known dispersing agents. In recent years, however, increasing attention has been paid to the development of rapid and very rapid dyeing methods and it is becoming common practice to dye under pressure at temperatures up to about 145"C. This applies particularly to the dyeing of polyester fibres where temperatures in the region of 1300C are in regular use and temperatures as high as 145"C have been suggested. In addition to such high dyeing temperatures, the concentration of dye in the dye-liquor has been increased considerably, and in order to obtain rapid contact with the textile material, which may be densely packed, vigorous pumping of the dye-liquor through the textile package is essential. The conditions of dyeing are therefore very severe, involving high temperatures, relatively high concentrations of dye and highly turbulent flow together with high shearing forces. All of these factors are known to be very detrimental to the stability of dispersions.

In addition to these physical factors, other factors leading to instability are involved, and these are of a chemical nature. Nonionic surfactants may be present in the dye-liquor either deliberately added as levelling agents, or carried in by the textile material as a residue from the scouring process, or they may be present as components of dyeing auxiliaries. Nonionic surfactants frequently interact with anionic surfactants to form addition complexes or possibly mixed micelles. This depletes the dye-liquor of its stabilising dispersing agent and this in turn may lead to the aggregation of the disperse dye.

Some of these causes of instability in a disperse dye-liquor are of quite recent origin and were certainly not considered when the dispersing agents mentioned above were under development. Not surprisingly, therefore, these dispersing agents are not always adequate and aggregation of the dye in the course of dyeing is not uncommon. This situation has led to the search for alternative dispersing agents.

According to the present invention there are provided aqueous dispersion preparations or powder preparations comprising a water-insoluble or sparingly soluble dye and a dispersing agent, which dispersing agent is a water-soluble alkali metal or ammonium salt of a modified condensation product of one of the following classes of phenolic condensate: Class 1 : the sulphonic acid of phenol and/or one or more other phenolic compounds reacted with formaldehyde and in addition, if desired, urea.

Class 2 : the sulphonated condensation product of phenol and/or one or more other phenolic compounds reacted with formaldehyde, Class 3 : the reaction product of a mixture of phenol and/or one or more other phenolic compounds, formaldehyde and sodium sulphite or sodium bisulphite or sodium metabisulphite and in addition, if desired, urea, the said modification comprising reaction of the condensate with either: (a) an etherifying agent or (b) an esterifying agent so that the phenolic groups originally present in the condensation product are at least partially replaced by ether or ester groups respectively.

The three classes of condensation product specified above are well-known commercially as synthetic tanning agents. They have also been used from time to time as dispersing agents, but in general they have not been so widely used as the naphthalene based dispersing agents or the lignosulphonates. We were, therefore, surprised to find that when these products were modified by etherification or esterification, the products were particularly suitable for use as dispersing agents for water-insoluble or sparingly soluble solids, especially dyes of the disperse class. When so employed, they have been found to yield excellent dispersions of dye which frequently show excellent stability under high temperature dyeing conditions and in the presence of nonionic surfactants.

The technology by which suitable dispersing agents may be incorporated with water-insoluble or sparingly soluble dyes, especially disperse dyes, to produce aqueous dispersion preparations or powder preparations is well known. Consequently in the production of preparations in accordance with the present invention, in either the powder or liquid form, the dispersing agent may be added to the dye (preferably a disperse dye) press-cake before, during or after grinding, although it is preferred to add at least part of the required amount of dispersing agent before comminution by, for example, ball milling or perl milling (perl is a registered Trade Mark). The amount of dispersing agent required will vary widely, depending upon the particular dye and the physical state of the dye in the press-cake, and amounts up to 100% of the weight of dry dye may be required. The amount of dispersing agent necessary, will also be, to some extent, determined by the mechanical characteristics of the grinding equipment, and also the time available for comminution.

After comminution, it is usual to add more dispersing agent and to dry the dispersion to form a dry dye powder. This is commonly brought about by spray drying. Alternatively the dispersion may be kept in the liquid state, perhaps with the addition of a thickening agent, humectants and solvents. These further processes make additional demands upon the dispersing agent. Thus after spray-drying, the dye-powder must be readily wettable and redispersable, and the liquid dispersions must be stable to storage, preferably without sedimentation, or if sedimentation does take place, the sediment should be easily redispersable.

Further demands on the dispersing agent are made during dyeing, particularly at high temperatures under conditions of high shear and in the presence of nonionic surface-active agents.

The dispersants described herein have been found to be particularly suitable for use under the conditions outlined above.

Also according to the present invention there is provided a dyebath prepared from a water-insoluble or sparingly soluble dye in the form of an aqueous dispersion preparation or powder preparation of the invention.

According to a further embodiment of the present invention there is provided a process of colouring fibres and/or fabrics using a water-insoluble or sparingly soluble dyestuff which has been prepared in the form of an aqueous dispersion preparation or powder preparation of the present invention.

The methods of preparing the three classes of condensation products specified above have been the subject of many patents. Bulk methods of production have been very fully documented in B.I.O.S. Final Report No. 762, but the following brief description will indicate the general methods of preparation used: Class 1: the phenol and/or one or more other phenolic compounds is/are sulphonated to give the mono-sulphonic acid and then after dilution with water to moderate the subsequent reaction, they may be reacted with a commercial, aqueous solution of formaldehyde and after completion of this reaction the product may be neutralised, normally with either caustic soda, sodium carbonate or ammonia. It is sometimes preferred to add a limited amount of urea to the sulphonation product before reacting with the formaldehyde. The amount of formaldehyde used may vary considerably but it must not be so large that cross-linking takes place with consequent loss of solubility of the condensate in the water.

Class 2: the phenol and/or one or more other phenolic compounds is/are reacted with formaldehyde to form a resin which is not cross-linked and is soluble in solvents such as ethanol and acetone. This resin, in the anhydrous condition is sulphonated with sufficient sulphuric acid to confer water-solubility. The properties of such a product are very dependent on the degree of sulphonation.

Class 3: the phenol and/or one or more other phenolic compounds is/are mixed with formaldehyde and sodium sulphite, sodium bisuiphite or sodium metabisulphite and are reacted, generally between 900 and 1200C, until the mass is water-soluble. Urea may be included if desired. The products of this class differ from those in Classes 1 and 2 in that the sulphonic acid groups are not directly attached to the aromatic nucleus, but are attached to it indirectly by means of a methylene group.

The water-soluble dispersing agents used in the preparations of the invention are obtained by partial or complete reaction of a water-soluble alkali metal or ammonium salt of one of the three classes of phenolic condensate described above with a suitable etherifying or esterifying agent.

Any of the well-known etherifying or esterifying agents may be used in the production of the dispersing agents of the invention but for the purposes of the present invention it is preferable to use those reagents which can react with phenolic hydroxyl groups in the presence of water whenever this is possible. Thus preferably, alcohols would not be selected for etherification nor acids for esterification, whereas alkyl halides or acyl halides would be more suitable, particularly when reacted under aqueous alkaline conditions.

Specific examples of etherifying agents are: dimethyl sulphate, diethyl sulphate, methyl iodide, ethylene oxide, propylene oxide, epichlorohydrin, glycidol, chloracetic acid and benzyl chloride; and of esterifying agents:- acetyl chloride, acetic anhydride, benzoyl chloride, benzene sulphonyl chloride, toluene sulphonyl chloride and ethyl chloroformate; but the invention is not limited to these compounds or their obvious equivalents.

The amount of etherifying or esterifying agent required is theoretically 1 mole per phenolic hydroxyl group but it is frequently advantageous to employ an excess, up to about 2 moles per phenolic hydroxyl group to ensure complete reaction of all these groups, and to allow for wastage resulting, for example, from reaction with water. On the other hand, it is not essential that all the phenolic hydroxyl groups should be reacted. A useful range is from 0.1 to 2 moles of etherifying or esterifying agent per phenolic hydroxyl group. Particularly useful products are obtained with 0.5 to 1.5 moles and preferably 0.5 to 1.1 moles of etherifying or esterifying agent per phenolic hydroxyl group.

The conditions of reaction are determined by the reactivity of the individual etherifying or esterifying agents, but it is preferred that the reaction should be carried out under aqueous conditions between 0 C and 1200C. Many etherifying and esterifying agents are capable of reacting under such conditions, particularly when sufficient alkali is added to neutralise any acidic reaction products. Those cited above are particularly useful.

The following preparations illustrate the production of typical dispersing agents suitable for use in the aqueous dispersion preparations or powder preparations of the present invention.

Preparation 1 108g commercial mixture of cresols containing 30-40% m-cresol and 100g 98% sulphuric acid were mixed and heated at 950-1000C for 11/2 hours to form a mixture of cresol sulphonic acids. The mixture was then cooled to 35"C and 100 ml. 30% W/vaqueous formaldehyde solution was added dropwise over 60 minutes, maintaining the temperature at 400C + 3"C by controlling the rate of addition with the help of external cooling when necessary. 100 ml.

water were then added and the temperature raised to 500C and maintained at 500-55"C for 10 hours. Additional water totalling 100 ml. was added in portions from time to time, during this period to facilitate stirring and maintain a manageable viscosity. The product was then diluted with a further 100 ml. water and neutralised with 118 ml. 50% W/v solution of sodium hydroxide, to produce Product A.

380g of Product A were mixed with 18 g sodium hydroxide and cooled to OOC. There was then added, whilst stirring vigorously, 45.9g acetic anhydride causing a considerable viscosity increase and a temperature rise of 16"C.

Preparation 2 94g Phenol and 100g 98% sulphuric acid were mixed together and heated at 95"-100"C for 11/2 hours. The resulting mixture consisting essentially of phenol sulphonic acid was cooled to 35"C and 100 ml. 30% W/v formaldehyde solution were added dropwise over 60 minutes maintaining the temperature at 40"C e 3"C by controlling the rate of addition with the help of external cooling when necessary. The temperature was then raised to 50"C and maintained at 50"-55"C for 4l/2 hours. Additional water totalling 200 ml. was added in portions from time to time, in order to maintain a workable viscosity and prevent gellation.

The product was then cooled and neutralised with 110 ml. 50% w/v sodium hydroxide solution to a pH of 7.5, to produce Product B.

315g of Product B were mixed with 18g sodium hydroxide and the resulting solution cooled to 0 C. There was then added, whilst stirring vigorously, 45.9g acetic anhydride. The temperature rose to 20"C and the viscosity increased, but to a less degree than in Preparation 1.

Preparation 3 94. 5g sodium sulphite were dissolved in 200 ml. water and to the resulting solution there was added and dissolved, 81 gm. commercial mixture of cresol isomers and 15 gm.

2-Naphthol. The temperature was then raised to 500C and 141 ml. 37% w/w formaldehyde solution was added dropwise whilst maintaining the temperature at 50"C i 3"C. On completion of this addition the temperature was raised to 950C and maintained at 95"C-100"C for 20 hours, before cooling to room temperature to produce Product C.

200g of Product C were cooled to 0 C and 29g acetic anhydride were added with stirring.

The temperature rose to 20"C but there was no appreciable viscosity increase.

Preparation 4 380g of Product A produced as described in Preparation 1 were mixed with 37g glycidol and heated at 60-65"C for 4 hours, stirring continuously under reflux. After cooling the product was adjusted to pH 7 with sulphuric acid.

Preparation 5 200g of Product C prepared as described in Preparation 3 were mixed with 23.9g glycidol.

The mixture was stirred and heated at 60-65 C for 4 hours in the same manner as Preparation 4. The pH of the product was then adjusted to 7 with sulphuric acid.

The invention is further illustrated by, but not limited to, the following Examples.

Example I 25g dried press cake of C.I. Disperse Orange 76 were added to 14g of the product of Preparation 4 (solids content 44%) and sufficient water was added to bring the total weight to 1-OOg. This mixture was milled in a laboratory ball mill until the particle size was in the range 1-3 ,um. To this dispersion was added a further 37g of the same dispersing agent, 4.5g diethylene glycol and water bringing the total weight to 150g, thus simulating the standardisation process for a commercial dye in liquid form (Dyeing Liquid A).

Similarly 16g dried press cake of C. I. Disperse Blue 64 was milled with 10g of the product of Preparation 4 with sufficient water to make to 100g. To this dispersion was added a further 42g dispersing agent, 4.5g diethylene glycol and sufficient water to make up to 150g (Dyeing Liquid B).

These two dyeing liquids were evaluated on a laboratory winch dyeing machine using the following dye-bath formulation: 2g/l Tinosol CF (Tinosol is a registered Trade Mark) 2g/l Permalose T (Permalose is a registered Trade Mark) 1g/l Dyeing Liquid A lg/l Dyeing Liquid B The machine was loaded with 10 yards polyester fabric (7" wide) and the liquor ratio was 10:1. The temperature was raised from 50 to 900C at 2"C/Min. and held at this temperature for 15 minutes. The dyebath was then cooled to 600C and dropped. The fabric was then spun dried. In this condition, the fabric was examined and the number of spots or stains was counted. The condition of the fabric was also noted.

The experiment was repeated using Product A from Preparation 1, which had not been etherified, as a control. The following results were obtained: Dispersing Agent No. of Stains Comments Product of Preparation 4 32 Fairly clean and level Product A 118 Very unlevel & dirty This experiment shows the beneficial effect which may result from blocking the phenolic groups under conditions which were already known to be severe.

Example 2 47.4g Serilene (Serilene is a registered Trade Mark) Red 2BL (Cl 60756) press-cake (=25g dry dye) was milled with 18.75g of the product of Preparation 1 (containing 44% solid matter) and 58.9g water in a laboratory ball mill until the particle size was 2 Rm or less.

At the same time, an otherwise identical milling was carried out using the equivalent amount of a naphthalene sulphonic acid/formaldehyde condensate as dispersing agent. In the time allowed, there were in this case numerous dye particles greater than 2 ijm in diameter.

750 ml. of a 1.5% (based on total solid matter) dispersion of each of these milled pastes were charged in turn into a pressure vessel. The temperature was raised to 1350C and after 5 minutes 250 ml. of the contents were blown through two 9 cm. Whatman No. 1 filter papers (Whatman is a registered Trade Mark). These filter papers were then dried and retained.

The contents of the pressure vessel were then allowed to cool to 1000C and a further 250 ml.

were passed through two clean filter papers. The purpose of this latter filtration was to determine whether crystallisation took place on cooling from 135 to 1000C.

The results obtained are shown in the following table: Dispersing Agent Temp. Appearance of Filter Papers Product of Preparation 1 135 Clear and uniform; no signs of any deposit of dye 100" Very slightly patchy; no signs of any deposit of dye.

Naphthalene based 135 Some deposit unevenly dispersing agent distributed over the filter paper 100" Filter paper completely covered by deposit of dye.

Example 3 A similar comparison was made with Serilene Orange BL (Cl 26080) using the product of Preparation 4. The composition of the milled paste in one case was: Serilene Orange BL press-cake 87.1g (=25g dry dye) (Serilene is a registered Trade Mark) Product of Preparation 4 (44% solid) 8.4g Water 13.3g and in the other identical except for the replacement of the dispersing agent by the equivalent amount of the naphthalene based dispersant.

The results obtained from the filter tests are shown in the following table: Dispersing Agent Temp. Appearance of Filter Papers Product of Preparation 4 135 Clear with slight patches of darker colour; 100" Very slight deposit of dye uniformly over paper.

Naphthalene based 135 Fairly heavy deposit of dye on dispersing agent paper 100" Heavy deposit of dye WHAT WE CLAIM IS: 1. An aqueous dispersion preparation or powder preparation comprising a waterinsoluble or sparingly soluble dye and a dispersing agent, which dispersing agent is a water-soluble alkali metal or ammonium salt of a modified condensation product of one of the following classes of phenolic condensate: Class 1 : the sulphuric acid of phenol and/or one or more other phenolic compounds reacted with formaldehyde, Class 2 : the sulphonated condensation product of phenol and/or one or more other phenolic compounds reacted with formaldehyde, Class 3 : the reaction product of a mixture of phenol and/or one or more other phenolic compounds, formaldehyde and sodium sulphite or sodium bisulphite or sodium metabisulphite.

the said modification comprising reaction of the condensate with either; () an etherifying agent or (b) an esterifying agent so that the phenolic groups originally present in the condensation product are at least partially replaced by ether or ester groups respectively.

2. A preparation as claimed in claim 1, in which the dye is a dye of the disperse class.

3. A preparation as claimed in claim 1 or 2, in which the dispersing agent is derived from a class 1 phenolic condensate in which the sulphonic acid of phenol and/or other phenolic compound is reacted with formaldehyde and urea.

4. A preparation as claimed in claim 1 or 2, in which the dispersing agent is a class 3 phenolic condensate in which the reaction mixture also includes urea.

5. A preparation as claimed in any of claims 1 to 4, in which the dispersing agent has been prepared by the reaction of a water-soluble alkali metal or ammonium salt of a phenolic condensate from one of classes 1 to 3 as defined in claim 1, partially or completely with an etherifying or esterifying agent.

6. A preparation as claimed in claim 5, in which the amount of etherifying or esterifying agent is from 0.1 to 2 moles per phenolic hydroxyl group.

7. A preparation as claimed in claim 5 or 6, in which from 0.5 to 1.5 moles of etherifying or esterifying agent has been used per phenolic hydroxyl group.

8. A preparation as claimed in claim 5, 6 or 7, in which from 0.5 to 1.1 moles of etherifying or esterifying agent has been used per phenolic hydroxyl group.

9. A preparation as claimed in any one of claims 5 to 8, in which the reaction has been carried out under aqueous conditions between 0 C and 1200C.

10. A preparation as claimed in claim 1, substantially as hereinbefore described in any one of the foregoing Examples.

11. A dyebath prepared from a preparation as claimed in any one of claims 1 to 9.

12. A dyebath as claimed in claim 11, substantially as hereinbefore described in any one of the foregoing Examples.

13. A process of colouring fibres and/or fabric using a water-insoluble or sparingly soluble dye which has been prepared in the form of a preparation as claimed in any one of claims 1 to 10.

14. A process of colouring fibres and/or fabrics as claimed in claim 13, substantially as hereinbefore described in any one of the foregoing Examples.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (15)

**WARNING** start of CLMS field may overlap end of DESC **. The results obtained from the filter tests are shown in the following table: Dispersing Agent Temp. Appearance of Filter Papers Product of Preparation 4 135 Clear with slight patches of darker colour; 100" Very slight deposit of dye uniformly over paper. Naphthalene based 135 Fairly heavy deposit of dye on dispersing agent paper 100" Heavy deposit of dye WHAT WE CLAIM IS:

1. An aqueous dispersion preparation or powder preparation comprising a waterinsoluble or sparingly soluble dye and a dispersing agent, which dispersing agent is a water-soluble alkali metal or ammonium salt of a modified condensation product of one of the following classes of phenolic condensate: Class 1 : the sulphuric acid of phenol and/or one or more other phenolic compounds reacted with formaldehyde, Class 2 : the sulphonated condensation product of phenol and/or one or more other phenolic compounds reacted with formaldehyde, Class 3 : the reaction product of a mixture of phenol and/or one or more other phenolic compounds, formaldehyde and sodium sulphite or sodium bisulphite or sodium metabisulphite.

the said modification comprising reaction of the condensate with either; () an etherifying agent or (b) an esterifying agent so that the phenolic groups originally present in the condensation product are at least partially replaced by ether or ester groups respectively.

2. A preparation as claimed in claim 1, in which the dye is a dye of the disperse class.

3. A preparation as claimed in claim 1 or 2, in which the dispersing agent is derived from a class 1 phenolic condensate in which the sulphonic acid of phenol and/or other phenolic compound is reacted with formaldehyde and urea.

4. A preparation as claimed in claim 1 or 2, in which the dispersing agent is a class 3 phenolic condensate in which the reaction mixture also includes urea.

5. A preparation as claimed in any of claims 1 to 4, in which the dispersing agent has been prepared by the reaction of a water-soluble alkali metal or ammonium salt of a phenolic condensate from one of classes 1 to 3 as defined in claim 1, partially or completely with an etherifying or esterifying agent.

6. A preparation as claimed in claim 5, in which the amount of etherifying or esterifying agent is from 0.1 to 2 moles per phenolic hydroxyl group.

7. A preparation as claimed in claim 5 or 6, in which from 0.5 to 1.5 moles of etherifying or esterifying agent has been used per phenolic hydroxyl group.

8. A preparation as claimed in claim 5, 6 or 7, in which from 0.5 to 1.1 moles of etherifying or esterifying agent has been used per phenolic hydroxyl group.

9. A preparation as claimed in any one of claims 5 to 8, in which the reaction has been carried out under aqueous conditions between 0 C and 1200C.

10. A preparation as claimed in claim 1, substantially as hereinbefore described in any one of the foregoing Examples.

11. A dyebath prepared from a preparation as claimed in any one of claims 1 to 9.

12. A dyebath as claimed in claim 11, substantially as hereinbefore described in any one of the foregoing Examples.

13. A process of colouring fibres and/or fabric using a water-insoluble or sparingly soluble dye which has been prepared in the form of a preparation as claimed in any one of claims 1 to 10.

14. A process of colouring fibres and/or fabrics as claimed in claim 13, substantially as hereinbefore described in any one of the foregoing Examples.

15. Fibres or fabric whenever coloured by a process as claimed in claim 13 or 14.