This invention relates to a method of modifying the properties of textile fibres and keratinous materials, especially in connection with the coloration of textile fibres including wool, polyamide, silk and cellulosic fibres and keratinous materials including hair and fur. More specifically, the invention is concerned with the treatment at low temperatures, i.e. temperatures significantly lower than 100 ^β C, of textile fibres and keratinous material with a substantive linear polyamine derivative either before or as part of a dyeing process.

Wool has traditionally been dyed in boiling dyebaths, where the time of boiling is dependent on the rate at which the dye penetrates the body of the fibre.

Thus, for dyes of large molecular size such as acid-milling and premetallised dyes (which are used extensively because of superior fastness properties) prolonged periods of boiling are required to permit the slow-diffusing dye to fully penetrate the fibre and thereby maximise the color yield.

The deleterious effect of boiling dyebaths on certain properties of keratin fibres, especially under acid or alkaline conditions, has been well documented; a wool fibre can lose tensile strength, suffer loss of weight and become yellow under such conditions. Thus, a method of applying dyes to wool textile fibres at temperatures lower than 100 ^β C would not only minimise fibre damage, but would also effectively lower energy costs incurred in heating the dye-containing medium.

Previous research has demonstrated that lower members of the polyethyleneamine series, such as tetraethylenepentamine, when applied to wool prior to dyeing, greatly increased the rate of dye exhaustion. It was also shown that if the temperature of dyeing was restricted to 70° to 80 ^β C, the dye was uniformly distributed through the fibre.

An inhibiting disadvantage in employing unmodified polyamines for a low-temperature dyeing pretreatment is the necessity to adopt a pad-on/dry process; this procedure is a consequence of the fact that polyamines are not substantive (i.e they do not spontaneously migrate from solution to fibre) , and must be applied to the fibre by mechanical means.

We have now found that the above disadvantage can be avoided if the polyamine is converted to a substantive derivative by attaching a linear alkyl chain to an amino group of the polyamine, either through an amide linkage

or a covalent bond.

The application of such a polyamine derivative to polyamide (i.e. nylon) fibres has also been found to significantly increase the color yield after a normal dyeing process. The polyamine derivative may be applied in a separate process stage or may be added to the dyebath prior to dyestuff addition. Pretreatment of silk with the polyamine derivative also improves the color yield compared with untreated silk, particularly when the silk is dyed at low temperatures.

Cellulosic fibres such as, cotton or viscose in woven or filament form, when treated with the polyamine derivative and placed in contact with dilute dye solutions, such as spent dye liquors, will rapidly absorb the dye from solution at ambient temperatures. The liquor can then be discharged without residual dye. This process is of ecological importance especially where the dye contains toxic metals such as chromium, cobalt and nickel.

According to one aspect of the present invention there is provided a method for modifying the low-temperature dyeability of textile fibres, which comprises applying to the fibres, either before or simultaneously with dyeing, a substantive linear polyamine derivative.

The above method is effective for textile fibres, including wool. However, for the treatment to be effective in the coloration process of other keratinous materials, such as hair or fur, a non-ionic levelling agent should be employed together with the polyamine derivative.

According to another aspect of the present invention

there is provided a method for modifying the low-temperature dyeability of a keratinous material, which comprises applying to the material, either before or simultaneously with dyeing, a substantive linear polyamine derivative together with a non-ionic levelling agent.

According to a further aspect of the present invention there is provided a composition for modifying the low-temperature dyeability of textile fibres, which comprises a substantive linear polyamine derivative, together with other additives conventionally used in the art of formulating compositions for textile fibres or keratinous material treatment.

According to a still further aspect of the present invention there is provided a composition for modifying the low-temperature dyeability of keratinous material which comprises a substantive linear polyamine derivative and a non-ionic levelling agent.

The present invention also extends to include textile fibres and keratinous materials which have been pretreated with a composition as defined above.

Keratinous materials include human hair and fur. Human hair may be colored by application of the polyamine derivative and the non-ionic levelling agent followed by a water-soluble dye. The temperature of dye application must be limited to about 45"C because the scalp skin is sensitive to heat. Even at this relatively low temperature however, a considerable fraction of the applied dye is taken up by the hair fibre. To avoid allergenic problems which may arise with untested textile dyes, it is preferred that food dyes be employed. Because solutions of such dyes are near neutrality, damage to the hair is much less than that which occurs in

conventional hair dyeing processes which require highly alkaline conditions.

Preferably, the polyamine derivative has the general formula (I)

R-X-NH(CH ₂ -CH ₂ -NH) _n H (I)

wherein R is an alkyl group having from 7 to 18 carbon atoms, X is a carbonyl group or a covalent bond and n is 2, 3, 4 or 5. For wool dyeing, R preferably contains 15 carbon atoms, X is a carbonyl group and n is 3.

Preferably also the polyamine derivative is in the form of a water-soluble acid salt, for example an acetate.

The compounds of formula (I) are known and may be prepared in accordance with the methods described in U.S. Patent Nos. 2,765,324 and 3,753,772 and J. Chem. Soc.

Japan 55 441-2 (1952) . For example, a linear alkyl chain may be attached to a polyamine amino group either through an amide group by a condensation reaction with a fatty acid or a covalent bond formed by an alkylation reaction with an alkyl halide.

Preferably, the non-ionic levelling agent is a C ₈ -C _l;L ethoxylated fatty alcohol containing 5 to 8 ethyleneoxy units, such as, for example, ICI's Teric G9A 8.

In a particularly preferred embodiment, the non-ionic levelling agent may also be employed in the dyeing of textile fibres.

The polyamine derivative and the non-ionic levelling agent may be applied to the textile fibres and the

keratinous material by any suitable known method.

Apart from the dyeing of textile fibres and keratinous material, other applications where acylpolyamine condensates can be used include woolly sheepskin dyeing and wool fabric printing.

The maximum temperature that can be employed in wool-on sheepskin dyeing is in the vicinity of 60°C (due to the possibility of shrinkage of the tanned hide at higher temperatures) . The pretreatment described in this specification is thus effective in the coloration (to medium depths of shade) of the wool component of sheepskins with dyes which are resistant to light fading. Such an application is of advantage where colored sheepskins are employed as car seat covers.

Sheepskin dyeing, in accordance with the present invention, may be conducted satisfactorily at about 50 ^β C. Color shades derived by applying more than one dyestuff are also found to develop "on-tone" which means that the shade of color is constant throughout the dyeing process. This is advantageous, in that the ultimate color shade can be predicted with accuracy. This characteristic of multicomponent dyeings pertains to all temperatures.

In wool fabric printing, current practice employs a prechlorination stage to permit rapid penetration of the dye into the fibre both prior to and during the steaming operation. This preparation treatment can sometimes cause harshness of handle and yellowing of the substrate during steaming. A further disadvantage of chlorine- based preparations is that in the treatment liquour, in particular the neutralisation stage, a considerable quantity of organically-bound chlorine is discharged into the mill effluent. In certain EEC Countries,severe restrictions have been set regarding this so-called AOX

(adsorbable organic halides) which may be discharged into river waters. Current chlorination procedures connot meet these requirements. Accordingly, polyamine derivatives in accordance with the present invention may also be used in wool fabric printing and give prints with a colour yield comparable to, or better than, that given by prechlorination treatments without the disadvantages mentioned above and with the added advantage that the derivatives can be applied by pad or exhaustion without the need for a heat fixation step.

Similarly, treatment with polyamine derivatives in accordance with the invention can be used to advantage in silk printing and dyeing where they considerably enhance the color depth achieved, when compared to untreated silk.

The invention is further described as illustrated by the following non-limiting examples.

Example 1 - Preparation of Acylpolyamine Condensates

The polyamine (NH ₂ (CH ₂ -CH ₂ -NH) _n H; n=3,4 or 5) and 10% molar excess of the appropriate acid (C ₈ -C ₁₈ ) were heated under reflux in toluene for a period of time necessary for the azeotropic removal of 1 mole equivalent of water. The solvent was distilled off leaving a viscous residue which was dissolved in dilute (20% v/v) acetic acid (40% solids content) at 80°C. When cooled, the resulting mixture formed a fluid paste which was easily dissolved in water to form a clear solution of pH 5.

Example 2 - Preparation of Alkylpolyamines

The appropriate alkyl bromide ( ^c ₈ ~C _lg ) , and an equimolar amount of the polyamine used in Example l and butanol were heated under reflux for 1 hour. The solvent was removed by distillation until a temperature of 150"C was reached. The residue was then cooled and dispersed in dilute NaOH. The insoluble product was extracted with ethyl acetate which was then removed under vacuum. The residue was dissolved in dilute acetic acid (10% v/v) to give a solids content of 10%.

Example 3 - Dyeing

A wool fabric piece was run in water (for 10 minutes at 25 ^β C) containing the compound of formula (I) wherein X=CO, R=C ₁₅ and n=3 (hereinafter called PAL-TETA) and Teric G9A 8 at levels 0.1% and 2% (on the weight of fibre) , respectively. Sodium acetate (1%) was added and the temperature increased to 50 ^β C over 20 minutes. The pH was then adjusted to 4.5 and the dye (3% of a 1:2 premetallised black or navy) added. The bath was run for 10 minutes and the temperature raised to 85°C to 40 "C over 30 minutes and held at 85 ^β C for 90 minutes. The bath was cooled and the fabric rinsed in cold water. The bath was virtually completely exhausted and little dye was removed on rinsing. The color yields and wet fastness for the three dyes are shown in Table 1'and compared with conventional dyeings carried out at the boil according to the manufacturer's recommended method.

A dyeing temperature of 90 ^β C is recommended for deepshades (3-5%) of premetallised dye. The dyeing temperature may be lowered to 85 ^β C for premetallised dyes in pale to medium colour depths, and to 75"C for acid levelling and milling colours in all shade depths without affecting the fastness properties relative to conventional dyeings.

TABLE 1

Rubfastness ISO 3 Washfastness

Dye Temp ^K/S max Wet Dry Effect Wool

Cotton

( ^β C) on Shade Stain Stai]

1 100 26.4 3-4 4-5 5 3-4 3-4

85 29.4 3-4 4-5 5 3 4

2 100 27.0 3 4-5 4 2-3 4-5

85 27.8 2-3 3-4 4 3 4

3 100 23.8 4 4-5 4-5 2-3 4-5

85 25.5 3-4 4 4-5 2 4

In Table 1 the following dyes were used:

1 - Acidol Black M.SR (BASF)

2 - Neutrichrome Navy S.BLL(ICI) 3 - Lanaset Navy Blue R (Ciba-Geigy)

All members of the series of polyamine derivatives, having the general formula (I) wherein X=CO, R=alkyl group having an odd number of carbon atoms and n=2 to 5 and wherein X=-(bond), R=alkyl group having an even number of carbon atoms and n=2 to 5, were effective in promoting dye diffusion at lowered dyebath temperatures, but differed in the fastness properties they conferred on the resultant dyeing. The best results were obtained with compounds of formula (I) wherein X=C0, R=C ₁₁ and C.g, n=3; X=C0, R=C ₁₃ and C ₁₅ , n=5; and X=-(bond), R=C _g , n=3.

Example 4 - Dyeing of Woolly Sheepskins

A woolly sheepskin was drummed in water at room temperature and the pH was adjusted to 5 to 6 by addition of ammonia (10 ml cone NH.OH/kg skin) . A compound of formula (I) wherein X=C0, R=C, ₃ and n=3 (hereinafter referred to as MYR-TETA) was added at a level of 1% (on the weight of hide) and drumming continued for 10 minutes. The temperature was raised to 50 ^β C over 30 minutes and acetic acid (0.1g/l) and Teric G9A 8 (0.5g/l) were added. After 15 minutes the dye (0.5g/l) was added and the drumming was continued for 30 minutes. The pH was adjusted to 3.5 to 4.5 by the addition of formic acid and the drumming continued for a further 30 minutes. The liquor was then drained and the dyed skin rinsed in warm water. The results are set out in Table 2.

TABLE 2

Dye Pretreatment (K/S max)

None Polyamine

Lissamine Yellow N 8.2 27.2

Lissa ine Orange 2G 27.1 36.2

Lissamine Red B 9.4 22.9

Nylomine Blue AG 25.9 36.6

Example 5 - Wool printing

The fabric preparation was carried out by exhaustion or pad roll treatment with a polyamine derivative. A treatment level between 0.3 and 0.8% was employed depending on the class of dye. The preferred polyamine for acid leveling, milling and certain premetallised dyes was the compound of formula (I) wherein R= C ₁₃ , X=CO and

n=4 (hereinafter referred to as MYR-TEPA) . The fabric was dried at 70 ^β C, pressed and then printed with a paste of the following formulation:

700 gm Indalca PA-3 (13% stock)

100 Urea

30 Glyzin A (BASF)

50 Ammonium tartrate

5 Teric G9A 8 X Dye

120 Water

The print was air-dried, steamed for 20 to 40 minutes and then washed off in cold water followed by warm water containing a rinse-off agent (e.g. Sandopur DK; lg/1) as recommended by the dye manufacturer (Sandoz) . The colour yields for several milling and premetallised dyes are set out in Table 3. The wet-fastness results for an individual metallised dye are set out in Table 4.

TABLE 3

PRINT COLOUR YIELDS (K/S max) Pretreatment

Dyestuff g/Kg None Chlorine Polyamine

Neutrichrome 20 15.8 18.6 17.4

Orange SR

Neutrichrome 40 22.1 28.6 25.9

Black MR

Lanasyn Navy 30 22.0 28.1 24.5

S-BL

II 5 7.8 9.0 8.6

Lanasyn Dark 30 18.2 26.9 23.3

Brown S-BL

Snadolan Milling 20 16.6 19.8 20.0

Red NRL

Coomassie Red 2R 20 17.8 19.7 19.9

Sandolan Milling 20 11.0 17.8 15.1

Violet NFBL

Carbolan Blue 2G 15 9.0 10.7 12.5

TABLE 4

COLOUR FASTNESS (Lanasyn Navy SBL)

Change of Wool Cotton Nylon

Pretreatment Shade Stain Stain Stain

ALKALINE PERSPIRATION (TM 174)

None 4-5 4-5 4-5 4-5 Chlorine 4-5 4-5 4-5 4-5 Polyamine 4-5 4 4 4

MACHINE WASHING FASTNESS (TM 193)

None 4-5 4-5 4-5 3-4 Chlorine 4-5 5 4-5 3-4 Polyamine 4-5 4-5 4-5 4

The monoamido condensate used in the following examples is derived from stearic acid and triethylenetetramine (hereinafter described as ST-TETA) .

Example 6 - Polyamide Dyeing

Nylon 6.6 knitted fabric was treated with a solution of ST-TETA (0.2 to 0.5% on the weight of the nylon fabric) . The solution was adjusted to pH 7 with ammonia or acetic acid at 40 ^β C in a circulating liquor dyeing machine. After 20 minutes the bath was replaced with a solution of ammonium acetate (5%) and adjusted to pH 4.5 with formic or acetic acid. The liquor was circulated for 10 minutes before addition of the dissolved dyestuff. The temperature was maintained at 30"C for 10 minutes and then raised to 98"C over 50 minutes and held at 98 ^β C for a further 30 minutes. The fabric was rinsed in warm water.

Colour fastness and relative colour yields following 0.5% ST-TETA treatment are set out in Table 5.

Example 7

The same treatment and dyeing procedure was employed as in example 4 except the dyebath was pH 5.5. The results are set out in Table 6.

Example 8

Nylon 6.6 fabric was treated in a circulating liquor dyeing machine with a solution of ammonium acetate (5%) and ST-TETA (0.1%) at pH 5.5 for 20 minutes at 40 ^β C. The dyeing procedure was the same as in examples 4 and 5. The results are set out in Table 7.

Example 9 - Silk Dyeing

Silk yarn (2-ply, degummed) was given a mild scour with an anionic detergent (neutral pH) at 50 ^β C for 20 minutes. The silk fibre was rinsed with water containing acetic acid (0.5 g/1) and then run in a solution of ST-TETA (0.25%) at pH 6.5 to 7.0 at 25 ^β C for 15 minutes. Ammonium acetate (5%) was added and the solution adjusted to pH 6.5 to 7.0. Dissolved dye (2%) was added to the circulating liquor and the bath was run at 40 ^β C for 10 minutes. The temperature was then raised to 75 ^β C over 40 minutes and held at 75 ^β C for a further 20 minutes. The bath was cooled to 50 ^β C, drained, and the fibre rinsed in water.

Table 8 shows that the treatment of silk with ST-TETA enables the fibre to be dyed with increased colour yields compared to untreated silk at temperatures considerably lower than 100 ^β C.

Example 10 - Removal of Dye From Spent Dye Liquor With

Cellulosic Substrates Treated With ST-TETA

Cotton yarns and viscose filament were treated with ST-TETA to the 1% level by circulating a solution of ST-TETA (2%) through the respective textile fibres at pH 6.5 and at 40*C for 30 minutes. The fibre was removed, rinsed in water and dried. Dye solutions (0.1 g/1, pH 4.5) were stirred with varying quantities of chopped fibre.

Table 6 shows the minimum quantity of treated fibre required to decolorise one litre of dye solution at room temperature. The time of contact of the fibre with the dye solution was less than 15 minutes. The effectiveness of cellulosic fibre compared to polyester (treated with

1% ST-TETA) is apparent from Table 9.

Removal of dye from the spent liquor by this means could be made more efficient by passing the liquor through a column packed with treated cellulosic fibre, either in loose or woven form. The substrate may be easily regenerated by stripping the absorbed dye with a mildly alkaline medium.

Example 10 - Hair Coloration With Water-soluble Anionic Dyestuffs

Hair is wetted out prior to dyeing in a solution (l%w/v, 40 ^β C, pH 6 to 7) of a compound of formula (I) wherein R= C ₉ , X= CO and n= 3 and Teric G9A 8 (1%). After 5 minutes, the hair is blotted dry with a paper towel and treated with a dye solution (e.g., Azorubine, 0.5%, pH 4) for 5 to 10 minutes. The hair is then rinsed in water and dried. The depth of the coloration is seen to be significantly greater compared to a similar dyeing in which the pretreatment had been omitted.

TABLE 5

10

o

15

TABLE 6

TABLE 7

10 o 9 o

15

fl Λ E 5

TABLE 8

10

09 IΛ

H

H

C 15 rπ

-i 20

25

TABLE 9

C

09 1/1

H

H 10 o C