identification of newer types of reactive dyes on cellulosic fibres – ii

524 JSDC DECEMBER 1970; JORDINSON AND LOCKWOOD

and NN-bis-#Lcyanoethylaniline show Amax at 525 nm, 525 nm, 499 nm and 474 nm respectively (13).

It would appear therefore that the electron displacements from NHEt groups are of a similar order to those from NHCHZCH,. OH, viz. the terminal hydroxyl group does not significantly modify the weak mesomeric electron release from the CH groups. In NHCHBCHaCN, the electron displacements resulting from the strong --I effect of the cyano group

are relayed to the amino nitrogen atom and must diminish the +M delocalisation from the nitrogen atom into the azobenzene chromophore, resulting in a decrease in the contribution of polar forms of the type VIII and IX and hence giving a hypsochromic shift in Xmsx. Thus, AA between the dyes aniline+N- ethylaniline and p-nitroaniline-fN-ethylaniline is 68 nm; with N-8-hydroxyethylaniline as coupling component, A A between the dyes derived from aniline and p-nitroaniline is of a similar order, viz. 65 nm, but, with N-8-cyanoethylaniline, the AA value is 53 nm, indicating the significance of the --I effect of the cyano group, even when a strongly electrophilic substituent is present at the other end of the dye molecule.

With dyes derived from NN-bis-/?-cyanoethylanilines, the hypsochromic shift is even more pronounced. Comparison, for example, of the dyes p-nitroaniline+aniline (Amax 431 nm) (lo), p-nitroaniline+N-methylaniline (Amrtx 464 nm) and p-nitroaniline-+N-/3-cyanoethylaniline (Amax 443 nm) shows that, although the 8-cyanoethyl group is hypsochromic compared with alkyl, it is bathochromic compared with H. The dye p-nitroadhe+ NN-bis-8-cyanoethylaniline however shows Am,, 432 nm, i.e. the additional 8-cyanoethyl group shows a hypsochromic shift relative to H. This abnormal hypsochromic effect, which evi- dently does not arise entirely from polar factors, may be due to steric factors. The partial negative charges resulting from the --I effect of each of the cyano groups, viz.

must result in a repulsion between the two terminal negative dipoles, with subsequent additional steric displacement with loss of coplanarity and decrease in the transmission of polar factors originating in the side-chains to the azobenzene molecule. A similar repulsion of negative charges arising from the --I effect of both the CN and the OH groups in dyes derived from N-8- cyanoethyl-N-8-hydroxyethylanilines also offers some explana- tion of the diminished hypsochromic shift of the /3-cyanoethyl group in this type of substituent, c.f. aniline+N-,%hydroxyethylaniline (Amax 398 nni) and aniline+N-/I-cyanoethyl-N-fl- hydroxyethylaniline 397 nm).

* * * We thank The Yorkshire Dyeware and Chemical Co. Ltd for

the award of a grant to one of us (I.B.).

(MS. received 25 June 1970)

References 1 Pete1 s. J. Chromatography, in press. 2 Brode, Gould and Wyman, J. Amer. Chem. S O C . , 74 (1952) 4641. 3 Idem, ibid., 75 (1953) 1856. 4 Blaisdell, J.S.D.C., 65 (1949) 618, 5 Birnbaum, Linford and Style, Trans. Faraday Soc., 49 (1953) 735. 6 Bock, Angew. Chem., 4 (1965) 457. 7 Mehta and Peters, unpublished. 8 Yagupolskii and Gandel'sman, Zhur. obsch. Khim., 35 (1965) 1252. 9 Dickey, et al., Amer. DyestufRep., 54 (1965) 596.

10 Brode, Seldin, Spoerri and Wyman, J. Amer. Chem. Soc., 77 (1955)

11 Cilento, Miller and Miller, Acta Un. int. Cancer, 11 (1955) 632. I2 Lewis, Tetrahedron, 10 (1960) 129. 13 Muller, Chimia, (1968) Supplementary volume, p. 69.

2762.

Publications Sponsored by the Society's Identification of Dyes Com mittee-\/I I I

Identification of Newer Types of Reactive Dyes on Cellulosic Fibres - I1

F. JORDINSON AND R. LOCKWOOD

Dyeing Section, Department of Pure and Applied Chemistry, Huddersfield Polytechnic, Huddersfield

The reactive systems and chromogens present in further types of reactive dyes are briefly discussed. The results are described of tests on dyeings (or prints) of selected reactive dyes on cotton, carried out to distinguish between the various chemical classes and to place them in their apparent position in Clayton's Tables. Particular attention is paid to the black reactive dyes, and a scheme is proposed

for differentiating between dyeings of 25 different black reactive dyes on cotton.

Since the publication (1) of our last paper dealing with the identification of reactive dyes, we have received dyeings (or prints) on cotton of new members of existing ranges of reactive dyes and of new ranges of reactive dyes so far not examined. These have been tested according to the general procedure described earlier (I), with one minor alteration. It was thought unnecessary to have two methods of using alkaline dithionite as a reducing agent, viz. the method suggested by ICI (2) and that of Thumm and Benz (3). The former was used for identifying dyeings of earlier types of reactive dyes on cellulosic fibres

(excluding blues) by reduction with ammoniacal sodium drthio- nite (no specific concentration was suggested), followed by diazotisation of the residual amine attached to the cellulose and coupling with 8-naphthol. In some instances an orange or red was produced which confirmed the presence of a component from a dye that had reacted with the cellulose. This test had limited application, but the use of the reagent as a general alkaline reducing agent (substituting sodium hydroxide for ammonia) was continued. Throughout, the results with it were similar to those obtained with Formosul G (Clayton), but 011 the

IDENTIFICATION OF REACTIVE DYES ON CELLULOSIC FIBRES-11 525

whole it was not so effective a reducing agent. Consequently, it was decided to restrict the use of alkaline dithionite to the method of Thumm and Benz. They found that a short (30 s) treatment at room temperature readily reduced anthraquinone and phthalocyanine reactive dyes on cotton.

Two of the tests used, viz. Formosul G and sodium hydroxide, are also used in Clayton’s Tables. The Formosul G test is purely chemical and is valid irrespective of the application class of a dye. The sodium hydroxide test, however, is a physical test by means of which dyes are placed in one of two categories, those which are stripped (direct dyes) and those which are not (vats, sulphur, azoic). Reactive dyes cannot be included in Clayton’s Tables but nevertheless the results obtained with the sodium hydroxide test are given, for convenience, as one or other of the Clayton categories.

Tests on dyeings of further Solidazol (CFM) and Basazol (BASF) dyes will now be described before passing on to other ranges of reactive dyes.

Solidazol Dyes (Continuation) These dyes are now listed in the Additions and Amendments

to the Colour Index (4). The six Solidazol dyes examined previously ( I ) are all stated to be monoazo dyes:

Solidazol Brilliant Yellow 4G Golden Yellow GC Orange G Brilliant Pink RL Brilliant Pink BR Brilliant Rubine RR

C.I. Reactive Yellow 40 Orange 31 Orange 32 Red 69 Red 70 Red 71

TABLE 1 Behaviour of Solidazol Brilliant Blue FBR (C.I. Reactive Blue 53)*

Test Boil for 2 min in 5 % NaOH (Clayton)

Hoechst solvents test Acid cross-dyeing test (Bode)

Formosul G (Clayton) Acid stannous chloride (FH)

Alkaline dithionite (Thumm and Benz) ‘Anthraquinone chromogen

Test

Boil for 2 min in 5 % NaOH (Clayton)

Hoechst solvents test Acid cross-dyeing test (Bode)

Formosul G (Clayton)

Acid stannous chloride (FH)

More than one reactive system appears to be used in the Solidazol dyes. Some are thought to have an acrylamide structure (3, like the Primazin dyes; the prints examined behaved in the same way as Primazin and Primazin P prints (or dyeings). The characteristics of all these dyeings may be sunimarised as follows:

(1) Serious loss of coIour when subjected to Clayton’s dilute sodium hydroxide test, but no staining of the white cotton

(2) Excellent resistance to the Hoechst solvents test (3) Variable resistance to the acid cross-dyeing test (Bode), in rzgard

to both loss of colour and staining of white wool. Solidazol Brilliant Blue FBR (C.I. Reactive Blue 53) is stated

by Wegmann (5) to be a dichlorophthalazine dye. A print on cotton of this dye behaved as described in Table 1. Unlike the six Solidazol prints previously examined, this one was resistant to alkali and so would fall into a different section of Clayton’s Tables (6). It also stood up well to Bode’s acid cross-dyeing test. The effect of reducing agents indicates that it is an anthraquinone dye, as stated in the Additions and Amendments to the Colour Index.

Basazol Dyes (Continuation) Prints on cotton of six of these dyes have already been

examined. Wegmann has suggested (7) that, strictly speaking, they are not true reactive dyes, as they are not linked to the fibre by dye-fibre bonds. The fixing agent cannot be fixed to cellulose, but with one exception, viz. Basazol Black Brown R ((2.1. Reactive Brown 15), the Basazol prints examined were completely resistant to the Hoechst solvents. However, Baumgarten (8) largely refutes Wegmann’s views. It was thought advisable to test

Result Slight loss of colour (Grey Scale 4) No staining of white cotton Very slight loss of colour (Grey Scale 4-5) Very slight loss of colour (Grey Scale 4-5) Slight staining of wool (Grey Scale 4) Yellow (dull blue with persulphate) Purple (cold) Yellow (warm) Original colour with persulphate Brown (dull violet with persulphate)

TABLE12 Behaviour of Basazol Dyes

Red Violet RL (C.I. Reactive Violet 15) (azo; copper complex)

Much loss of colour (Grey Scale 1)

No staining of white cotton Completely resistant Completely resistant Very slight loss of colour Very slight loss of colour

(Grey Scale 4-5R) Staining of wool Staining of wool

(Grey Scale 3) Permanently decolorised Brownish grey

Navy Blue B (C.I. Reactive Blue 62) (azo; cobalt complex)

Much loss of colour (Grey Scale 1)

No staining of white cotton

(Grey Scale 4-5)

(Grey Scale 2-3)

Faint brown with persulphate As above

Alkaline dithionite (Thumm and Benz)

Conc. HNO3 and acid stannous chloride (FH)

Decolorised Faint brown with persulphate Purple Original colour on rinsing Negative

Green BCL (C.I. Reactive Green 13)

(phthalocyanine)

Much loss of colour (Grey Scale 1-2)

Slight staining of white cotton Completely resisbant Very slight loss of colour (Grey Scale 4-5Y)

No staining of wool

Navy Original colour with persulphate Navy blue, then almost decolorised Original colour with persulphate Greenish blue Original colour on rinsing Negative


more Basazol dyes, so prints on cotton of three newer members of the range were examined. The results are given in Table 2.

The general behaviour towards sodium hydroxide, the Hoechst solvents, and acid cross-dyeing resembled that of the six dyes already tested. Thus the prints suffered severe loss in depth after boiling for 2 min in 5 % sodium hydroxide, which would place them, together with the other Basazol dyes, in the same section of Clayton’s Tables as the direct dyes. The green print also stained white cotton slightly, unlike the other two prints. The three prints were entirely unaffected by the Hoechst solvents but they differed in their resistance to acid cross-dyeing. With each the effect on the pattern was slight, but white wool was stained from the reddish violet and the navy prints but not from the green.

Both the reddish violet and the navy prints were decolorised by reducing agents, and persulphate caused no return of colour with the reddish violet and only a faint brown with the navy. The Additions and Amendments to the Colour Zndex list both of these as azo dyes, Basazol Red Violet RL being a copper complex and Basazol Navy Blue B a cobalt complex. When the Basazol Green BCL print was treated with cold acid stannous chloride, or with Formosul G, it changed to navy, the green being restored with persulphate. Similar behaviour was shown in the Thumm and Benz test (cold alkaline dithionite), but here the original colour was restored on rinsing with cold water, thus indicating a phthalocyanine dye. This conclusion is confirmed in the Additions and Amendments, but Basazol Green BCL (unlike Basazol Brilliant Blue GL, also a phthalocyanine dye) did not give a positive result with the Hoechst confirmatory test for such dyes using concentrated nitric acid followed by cold acid stannous chloride.

Elisine Dyes These dyes are made by Francolor and replace the Rkatex dyes

referred to in a previous paper (I). Francolor has informed us (9) that they contain either a dichlorophthalazine (I) or a chloro- benzothiazole (11) group as the reactive group, attached to the chromogen by an amide linkage at the 6-position.

P 1

Prints on cotton of four members of the range were subjected to the usual tests. The results are shown in Table 3.

Treatment in the alkaline solution used in Clayton’s Tables caused loss of colour in all cases, particularly from the yellow and red prints. Hence they would fall into the same section of the Tables as the direct dyes, although there was no staining of white cotton. The prints were resistant to the four Hoechst solvents, with the exception of that of Turquoise ULX, which became somewhat paler. An exactly opposite effect was observed in the acid cross- dyeing test, where only the turquoise print left the white wool unstained, and underwent no alteration in depth. This excep- tional behaviour of turquoise dyeings with the Hoechst solvents and in acid cross-dyeing, compared with all other dyeings of reactive dyes, has been reported previously (10).

Elisiane Turquoise 2 JLX is probably a phthalocyanine dye. The print behaved exactly as expected in the Thumm and Benz test for phthalocyanine reactive dyes, the colour changing at once to purple in the cold alkaline dithionite solution, the original turquoise blue being readily restored on rinsing with water. The yellow, red and bordeaux dyes are probably azo dyes, as all the prints were decolorised by strong reducing agents, no restoration of colour occurring with the yellow and the red. An interesting feature with the Bordeaux RL print was the appearance of a reddish brown when the decolorised pattern obtained with each reducing agent was treated with persulphate. This behaviour resembles that of Primazin Red P-3B (C.I. Reactive Red 52) and of three Solidazol dyes, viz. Brilliant Pink RL (C.I. Reactive Red 69), Brilliant Pink BR (C.I. Reactive Red 70) and Brilliant Rubine RR (C.I. Reactive Red 71). These four reactive dyes are listed as azo dyes in the Additions and Amendments to the Colour Zndex, so Elisiane Bordeaux also is probably an azo dye.

Reacna Dyes These reactive dyes were introduced by Acna in 1965. Accord-

ing to the Additions and Amendments to the Colour Index they are monochlorotriazinyl dyes, like the Procion H (ICI) and Cibacron (CIBA) dyes. The usual series of tests was carried out using dyeings on cotton of six members of the range. The results are given in Table 4.

When the dyeings were treated with boiling 5 % sodium hydroxide (2 min), white cotton was unaffected, except for slight staining with the Turquoise G3GL. The effect on the pattern

D-NHC O-(yCCl S’ D-mco-r: Test

Boil for 2 min in 5 % NaOH (Clayton)

Hoechst solvents test

Acid cross-dyeing test (Bode)



ranged from a serious loss in depth (Brown C-2R) to only a slight loss (Orange C-R); hence the Reacna dyes would not fall

TABLE 3 Behaviour of Elisiane Dyes

Brilliant Yellow 4RL Brilliant Red B Bordeaux RL Turquoise 2JLX Much loss of colour c

Completely resistant

Loss of colour Loss of colour Loss of colour (Grey Scale 3) (Grey Scale 2-3) (Grey Scale 2)

Staining of wool Staining of wool Staining of wool (Grey Scale 3) (Grey Scale 3) (Grey Scale 3)

Pale yellow Pale yellow Decolorised No change with persulphate Pale yellowish brown with

Permanently decolorised Decolorised As above

Much loss of colour (Grey Scale 2) (Grey Scale 1-2) (Grey Scale 3)

All dyeings-no staining of white cotton Very slight loss of colour

Some loss of colour

Very slight loss of colour (Grey Scale 4-5) (Grey Scale 4-5B)

Pale reddish brown with persulphate persulphate

persulphate Pale yellowish brown with

Some loss of colour (Grey Scale 3)

Some loss of d o u r (Grey Scale 3)

Very slight loss of colour (Grey Scale 4-5)

No staining of wool

--t --

Navy, then decolorised Pale green with persulphate

As above



Purple Original colour on rinsing Negative

IDENTIFICATION OF REACTIVE DYES ON CELLULOSIC FIBRES-II 527

Test

Boil for 2 min ,in 5 % NaOH (Clayton)




TABLE 4 Bebaviour of Reacna Dyes

Yellow GG Orange C-R Red GBR Turquoise CJGL Blue C-BG Brown C-2R (C.I. Reactive (C.I. Reactive (C.I. Reactive (C.I. Reactive (C.I. Reactive

Yellow 36) (azo) Orange 28) (azo) Red 61) (azo) Blue 48) Blue 47)

(Grey Scale 3) colour (Grey (Grey Scale 2-3) (Grey Scale 3) (Grey Scale 4) (Grey Scale 1-2)

(phthalocyanine) (anthraquinone) Loss of colour

f No staining of white cotton - cotton No staining of white cotton Very slight loss of No loss of colour Very slight loss of Loss of colour No loss of colour No loss of colour

Very slight loss of Loss of colour Loss of colour Slight loss of colour Much loss of colour

Scale 4-5) Slight staining of

colour (Grey colour (Grey (Grey Scale 3) Scale 4-5) Scale 4-5)

Slight loss of colour slight loss of colour Slight loss of colour Very slight loss of (Grey Scale 4) (Grey Scale 4) (Grey Scale 4) colour (Grey colour (Grey (Gfey Scale 3-4Y)

No staining of wool Slight staining of Staining of wool Scale 4-5G) scale 4-5) Stalning of wool wool (Grey (Grey Scale 2-3) No staining of wool Slight staining of (Grey Scale 3) Scale 4) wool (Grey

decolorised Pale orange with Pink with Pale greenish blue Grey with decolorised persulphate persulphate with persulphate persulphate

Very slight loss of Loss of colour

Scale 4) Permanently Decolorised Decolorised Purple Yellow Permanently

Acid stannous As above As above As above chloride (FH)



into one place in Clayton’s Tables. In this respect, they resemble the Levafix @ dyes, and differ from the other monochlorotriazinyl dyes (Procion H and Cibacron), the behaviour of which was described in an earlier paper (10). Towards the Hoechst solvents the dyeings were completely or almost completely resistant, with the exception of the turquoise, which suffered a noticeable loss of colour. As with turquoise dyeings of other types of reactive dyes, the Turquoise C3GL withstood the acid cross-dyeing test. The colours of the remaining five Reacna dyeings were only slightly affected in this test, but the degree of staining of white wool ranged from nil (Yellow C-G) to an appreciable stain with Red GBR.

The Additions and Amendments (4) state that the yellow, orange and red dyes are azo compounds, which was confirmed by the behaviour of the dyeings with reducing agents, followed by oxidising agents. A faint but definite pink was obtained when the reduced dyeings of the Red C-BR were treated with persulphate. Reacna Brown C-2R is also probably an azo dye, as the dyeing was permanently decolorised by each reducing agent, but in each case this was preceded by a change to purple. The Blue C-BG is an anthraquinone dye, the dyeing changing to yellow on reduction and the original blue being restored by treatment with persulphate, Reacna Turquoise C-3GL is a phthalocyanine dye, according to the Additions and Amendments to the Colour Index, and its dyeings, like those of other such reactive dyes, were first changed to purple with each reducing agent. On further treatment with acid stannous chloride the dyeings were practically decolorised, The dye conformed exactly both to the Thumm and Benz test and to the Hoechst confirmatory test for phthalocyanine reactive dyeings.

It is interesting to compare the reactions when dyed on cotton of this monochlorotriazinyl blue dye (Reacna Turquoise G3GL) with those of Procion Turquoise H-A ((2.1. Reactive Blue 71). This dye was marketed in 1967 and, if it resembles the earlier Procion H dyes, contains a monochlorotriazinyl group. Procion Turquoise H-A was only slightly affected by boiling 5 % sodium hydroxide (like the Reacna dye), and was more resistant to the Hoechst solvents. Both patterns were unaltered by acid cross-dyeing, but the Procion dye did stain white wool slightly,

Decolorised Yellow As above Original colour with

persulphate Royal blue Black Original colour Original colour

on msing on rinsing Positive Negative

whereas the Reacna dyeing gave no stain. Towards reducing agents, the Procion dyeing behaved similarly to the Reacna dyeing and it also gave positive results with the Thumm and Benz and the Hoechst tests for phthalocyanine reactive dyes. The two turquoise dyes therefore have similar wet-fastness properties when dyed on cotton.

Procion Supra Dyes In 1967 ICI introduced a new range of reactive dyes intended

for printing cotton and viscose rayon. These Procion Supra dyes are claimed to give high fixation, to have excellent washing-off properties and to give prints with very good light and wet fastness. A further claimed advantage is complete freedom from staining when the wet printed fabric is plaited down, even when only partially washed-off. The dyes are listed in the Additions and Amendments to the Colour Index, but no definite information is available about their chemical composition.

Prints on cotton of four Procion Supra dyes were examined and the results are given in Table 5.

Whereas dyeings (or prints) of the earlier Procion dyes were unaffected by boiling 5 % sodium hydroxide (2 min), the four Procion Supra prints suffered considerable loss in depth, although white cotton was unstained. These dyes would fall into another section of Clayton’s Tables. i.e. with the direct dyes. The two yellows and the red dye were completely unaffected by the Hoechst solvents, but the Supra Turquoise H-2GP showed a slight loss in depth, similar to that found with dyeings of the other turquoise reactive dyes. The prints showed high resistance to the acid cross-dyeing test, in regard both to loss in depth and to staining of white wool, but Supra Red H-4BP was slightly inferior to the other three dyes. This behaviour also differs from that of Procion M and Procion H dyeings in Bode’s test, which suggests that the Procion Supra dyes contain an entirely different reactive group. In fastness to boiling sodium hydroxide and to acid cross-dyeing they resemble the Remazol (FH) and Primazin dyes, although they are somewhat more resistant to alkali than either of these.

Towards reducing agents the red and the yellow prints behaved like azo dyes. Indeed, they are described as such in the Additions


and Amendments to the Culuur Index, which also states that Procion Supra Turquoise H-2GP is a copper phthalocyanine dye. The phthalocyanine structure was confirmed by Thumm and Benz’s test, but the Hoechst test gave a negative result. The print turned purple when spotted with concentrated nitric acid and became colourless with the acid stannous chloride. It would seem that blue reactive dyes based on a metal phthalocyanine structure do not respond positively to the Hoechst confirmatory test.

Levafix P Dyes During the last decade interesting developments have taken

place in the ranges of reactive dyes marketed by Bayer. The original Levafix dyes (1958) were followed by the Levafix E dyes (l961), which are suitable for dyeingcellulosic fibres by exhaustion methods. In 1966 the Levafix P dyes were introduced. These have a high degree of reactivity and were developed particularly for printing and padding processes; hence the suffix ’P‘. The Levafix P dyes are listed in the Additions and Amendments to the Culour

Index, but the reactive group present is not stated. Possible chromogens include azo, azo metal complexes, anthraquinone and phthalocyanine. All Levafix P dyes have the same reactive group, which is understood to be methylsulphonepyridine (11).

Dyeings on cotton of six L e v a h P dyes were examined, with the results as shown in Table 6.

In the test using 5 % sodium hydroxide, in no case was white cotton stained, and with five of the dyeings there was no loss in depth, indicating that the Levafix P dyes would fall into the same section of Clayton’s Tables as the original Levafix dyes, together with vat and sulphur dyes and azoic dyeings. The blue dyeing (Levafix Blue P3GL) lost some colour when treated with sodium hydroxide, as did dyeings of some Levafix blues (Brilliant Blue I-4G and Turquoise I-GG) (I). The Levafix P dyeings in all cases suffered some loss in depth in the Hoechst solvents, thus behaving similarly to Levafix and Levafix E dyeings or prints ( I ) . The behaviour towards Bode’s acid cross-dyeing test of the Levafk P dyes was intermediate between that of the Levafix dyes (which were unaffected) and the Levafix E dyes, which (except for Turquoise Blue E-G) were not resistant. Three of the six Levafix

TABLE 5

Behaviour of Procion Supra Dyes

Test

Boil for 2 min in 5 ”/, NaOH (Clayton)






Conc. HNOJ and acid stannous chloride (FH)

Yellow H-4GP Yellow H-2RP Red H-4BP Turquoise H-2GP (C.I. Reactive Yellow 51) (C.I. Reactive Orange 40) (C.I. Reactive Red 79) (C.I. Reactive Blue 63)

(monoazo) (monoazo) (monoazo) (copper phthalocyanine) Loss of colour Loss of colour Loss of colour Loss of colour

c All dyeings-no staining of white cotton- __ --f Some loss of colour

t No loss of colour __ - (Grey Scale 3-4) No loss of colour No loss of colour but redder Slight loss of colour No loss of colour but greener Slight staining of wool Very slight staining of wool No staining of wool

(Grey Scale 3) (Grey Scale 2) (Grey Scale 3) (Grey Scale 3)

(Grey Scale 4) (Grey Scale 4) (Grey Scale 4-5) Staining of wool

(Grey Scale 3-4) Decolorised Decolorised Yellow Almost decolorised Pale brown with Pale yellow with Pale orange brown with No change with persulphate

Decolorised As above Decolorised Decolorised Pale yellow with persulphate

persulphate persulphate persulphate

Pale orange with persulphate Pale green with persulphate Purple Pale greenish blue on rinsing Negative

Test

TABLE 6 Behaviour of Levah P Dyes

Brilliant Yellow Orange P-R Brilliant Red P-3B BrilliantjViolet Blue P-3GL Navy Blue P-RRL P-GG (C.I. Reactive (C.I. Reactive P-BBL (C.I. Reactive (C.I. Reactive (C.I. Reactive

((2.1. Reactive Orange 43) (azo) Red 81) (azo) Violet 18) (azo) Blue 54) (azo) Blue 67) (azo) Yellow 52) (azo)

Boil for 2 min in 5”4 Very slight loss of Very slight loss of Very slight loss of NaOH (Clayton) colour (Grey colour (Grey colour (Grey colour (Grey (Grey Scale 3-4) colour (Grey

Very slight loss of Some loss of colour Very slight loss of

Scale 4-5) Scale 4-5) Scale 4-5 ) Scale 4-51 Scale 4-5B)

Hoechst solvcnls lest




Turns scarlet in the alkali

~ .-

Slight loss of Some loss of Some loss of Slight loss of colour (Grey colour (Grey colour (Grey colour (Grey Scale 4) Scale 3) Scale 3-4) Scale 4R)

No loss of colour Slight loss of colour Loss of colour No staining of wool Very slight staining

___ All dyeings-no shining of white cotton

No loss of colour (Frey Scale 4)

of wool (Grey Staining of wool No staining of wool Scale 4-5) (Grey Scale 3)

(Grey Scale 3)

Decolorised Pale orange Pale yellow Yellow Very pale yellow No change with Pale orange brown Pale brown with

with persulphate persulphate with persulphate persulphate i All d yeings-permanent1 y decolorised--

Some loss of Some loss of colour (Grey colour (Grey Scale 3R) Scale 3)

(Grey Scale 3) Loss of colour

No staining of wool Slight staining of

Loss of colour (Grey Scale 3-4R)

wool (Grey Scale 4)

Pale yellow Pale yellow No change with No change with

persulphate persulphate

IDENTIFICATION OF REACTIVE DYES ON CELLULOSIC FIBRES-II 529

P dyeings stained white wool (usually slightly) and loss of colour occurred with four of them.

The Levafix P dyes examined are stated to be azo dyes (in the Additions and Amendments to the Colour Index) and in fact each dyeing was permanently decolorised by treatment with acid stannous chloride. Formosul G was less effective and only the yellow dyeing was completely decolorised. It is interesting to note that both blues (Levafix Blue P-3GL and Levafix Navy Blue P-RRL) are azo dyes, as are Drimarene Navy Blue Y-BL (C.I. Reactive Blue 8) and Basazol Navy Blue B (C.I. Reactive Blue 62), which we have tested. Thus they differ from the following blue reactive dyes previously examined (I, 10, 12):

Colour Index C.I. Reactive Blue

Procion Blue H-B 2 Levafix Brilliant Blue RR 12 Remazol Brilliant Blue R 19 Levafix Brilliant Blue E-B 29 Reacna Blue C-BG 47 Solidazol Brilliant Blue FBR 53 Primazin Brilliant Blue BL -

The above are anthraquinone dyes, but most of the blue reactive dyes examined were phthalocyanine dyes, viz:

Colour Index C.1. Reactive Blue

Procion Brilliant Blue H-7G 3 Cibacron Turauoise Blue G I Levafix Brilliant Blue I-3G 11 Reactone Turquoise Blue FGL 18 Levafix Turquoise Blue E-G 21 Levafix Brilliant Blue I-4G 23 Cavalite Turquoise 8G 30 Basazol Brilliant Blue GL 35 Reacna Turquoise C-3GL 48 Procion Supra Turquoise H-2GP 63 Primazin Turquoise G - Procion Turquoise H-A 71 Rt5atex Turquoise 2JLI - Elisiane Turquoise 2JLX -

In addition we have examined the following green reactive dyes, which are stated in the Supplement and Additions and Amendments to the Colour Index to be phthalocyanine dyes:

Colour Index C.I. Reactive Green

2

13

Levafix Brilliant Green I-B (22) Levafix Turquoise I-GG (I) 4 Basazol Green BCL (see Table 2)

The results of these tests show clearly that these three are ph t halocyan ine dyes.

We have also tested Procion Brilliant (Printing) Green BS and Procion Brilliant (Printing) Green 5GS (lo), and we concluded that they were probably mixtures containing a blue phthalocyanine component.

Identification of Black Reactive Dyeings A previous publication (I) contained a table in which five black

reactive dyes were differentiated on the basis of the results of spotting the respective dyeings (on cotton) with cold concentrated nitric acid, and of steeping the dyeings in cold concentrated sulphuric acid.

A much more comprehensive scheme for identifying dyeings on cotton of 25 different reactive blacks is now presented.

As in the initial test in Clayton's Tables, each pattern was treated at the boil for 2 min in 5 % sodium hydroxide in the presence of white cotton. The five dyes that withstood this treatment (loss in depth not less than 4 using the Grey Scale for assessing the change in colour) are listed in Table 7. According to Clayton's Tables these dyes would be grouped with vat and sulphur dyes and azoic dyeings, but the remaining 20 dyes (Table 8) fall into the other section of the Tables.

None of the black dyeings showed any staining of white cotton, except C.I. Reactive Black 17, which gave a slight but noticeable reddish stain. This dyeing also changed very much in hue after treatment with sodium hydroxide at the boil, turning to a very reddish violet, with a considerable loss in depth. The only other dye that showed a marked change of colour with sodium hydroxide was C.I. Reactive Black 18, which became violet but suffered little or no loss in depth.

The next test applied was Bode's acid cross-dyeing test. Of the dyeings listed in Table 7, two withstood this test, i.e. they showed little or no staining of white wool (4, 4-5 or 5 on the Grey Scale for Assessing Staining). These are placed in Section A of Table 7. Three dyeings were not fast to acid cross-dyeing and are shown in Section B of Table 7.

Table 8 is subdivided in a similar manner as a result of the cross-dyeing test. Thus Section A contains four dyes that are fast (as described above) and Section B sixteen .dyes that are not fast.

For differentiating further between the dyes in each table, the nitric acid spotting test proposed by Bode (12) was extremely useful, for most of the blacks could be satisfactorily characterised by means of this test. However, for complete differentiation and for confirmation, three further tests were used, of which steeping in cold concentrated sulphuric acid, followed by dilution of the acid extract with water (I), is considered the most important.

TABLE 7 Black Reactive Dyes Withstanding* 2-min Boil in 5% NaOH

Commercial name Colour Chromogen Conc. nitric acid spotting Conc. sulphuric acid steep Reduction test (acid Index pattern stain on extract on dilution stannous chloride) C.I. filter

Black Reactive paper

( A ) Dyes that show little or no staining of wool in the acid cross-dyeing test (Bode), i.e. rating 4 , 4-5 or 5 on Grey Scale for Assessing Staining

Levafix Grey IG 2 Violanthrone Yellowish None Pale brown Yellowish Greyish purple

Levafix Black P-R 21 Azo Black Violet Brownish Dull Redder, then decolorised grey grey

(redder) purple violet

(B) Dyes that show definite staining of wool in the acid cross-dyeing test (Bode), i.e. < 4 on Grey Scale for Assessing Staining

Drimarene Black Z-GL 4 Monoazo Purple Purple Violet Purple Grey Reactone Black RLF } Pinkish brown with

Procion Supra Black H-BP 20 Azo (metallised) Unchanged Violet Red Purple Bluish grey Procion Grey M-2R 18 Monoazo Brownish Faint Reddish Reddish Decolorised (slowly)

persulphate

(chromium complex) black grey violet violet 'Effect on pattern rating 4 4 on Grey Scale for Assessing Change in Colour


Each table records the full range of colorations obtained using the following standardised procedure. A small pattern was covered with concentrated sulphuric acid in a test-tube and allowed to stand for 30 min at room temperature, with occasional shaking. The colour of the extract was then noted and part of it poured slowly into cold distilled water in another test-tube,

After this test-tube had been shaken, the colour of the diluted extract was recorded.

The two additional tests mentioned above were (a) a reduction test with acid stannous chloride (I) and (b) spotting the dyeings with cold concentrated hydrochloric acid and observing any change in colour. This last test was of limited value and the

1'ABLE 8 Black Reactive Dyes not Withstanding* 2-min Boil in 5 % NaOH

Commercial name Coloirr Chromogen Conc. nitric acid Conc. sulphuric Reduction test Conc. Index. spotting acid steep (acid stannous hydrochloric

C.I. pattern stain on extract on dilution chloride) acid spotting

Black Reactive filter paper

( A ) Dyes that show little or no staining of wool in the acid cross-dyeing test (Bode), i.e. ratingl, 4-5 or 5 on Grey Scale for Assessing Stair&?

Remazol Black B 5 Disazo Bluish Faint Greenish Bluish Red then decolo- green green black green rised

Pale brown with persulphate

Levafix Black GL 7 Disazo Reddish Reddish Purple Grey Decolorised

14 Monoazo Greenish None Orange Reddish Decolorised Remazol Grey G Remazol Printing

brown brown (slowly)

grey with brown (slowly) red rim Black G

Procion Black H-2B Dark green None Dull green Green Purple then with light decolorised green rim

( B ) Dyes that show definite staining of wool in the acid cross-dyeing test (Bode), i.e. rating < 4 on Grey Scale for Assessing Staining

Procion Bfack H-G

Cibacron Black FR-D

Drimarene Grey Z-GL

Procion Black H-N

Procion Grey M-G

Cibacron Grey G-E

Primazin Grey PBL

Primazin Black B

Levafix Black E-RL

Basazol Carbon N

Procion Grey H-BR

Cibacron Pront Grey 2B

Elisiane Black RLX

Procion Supra Black

Cibacron Pront H-LP

Black G

Calcobond Black

1

3

6

8

9

13

15

16

17

19

22

23

Monoazo Brown

Monoazo Yellowish

A20 Violet brown

Monoazo Purple

Disazo Orange (metallised)

(copper complex)

Monoazo Greenish yellow

AZO Violet

A20 Greenish brown with green rim

(metallised)

AZO Purple

Azo (chromium Greenish complex) black

Monoazo Bright (metal complex) orange

Monoazo Khaki

Reddish

Reddish black

Unchanged

grey

Greenish black

Faint brown

Yellowish brown

Faint violet

Purple

Faint orange

Yellow

Pale bluish violet

Bluish grey

Purple

Pale olive

BI ue

Bluish

Dull

Purple

Blue

green

violet

Dull green

Dull pink

Dull green

Bright

Bluish purple

violet Yellow Dull bluish

green

Khaki Greenish blue

Faint violet Purple

Violet Purple

Bluish Purple

Dull green Grey

green

Brown

Violet

Reddish brown

Purple

Olive green

Dull violet

Violet

Bluish green

Purple

Yellowish

Bluish grey

green

Reddish brown

Purple

Purple

Blue

Dull green

Decolorised (slowly)


Almost decolorised


Decolorised Pale blue with

persulphate Decolorised


Purple, then

Yellowish decolorised

brown with persulphate



Red and then decolorised

Faint brown with persulphate

Unchanged

Grey (redder)

Purple

Grey (redder)

Bright reddish purple

Bluish grey Reddish grey

Dull green with persulphate

Decolorised Brownish violet (slowly)

Decolorised Dull purple (slowly)

Decolorised Unchanged Pale brown with

persulphate Bright red and

then decolorised

(slowly)

'Effect on pattern rating <4 on Grey Scale for Assessing Change in Colour

identification of newer types of reactive dyes on cellulosic fibres – ii

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