Rather more (about 1-1/2 per cent.) of this is required than of beta-naphthol.
=Alpha-naphthol= has similar properties to, and is used in the same way as, beta-naphthol; it develops much darker and rather duller colours, which are less fast to washing.
=Resorcine=, like naphthol, is insoluble in water, but it can be dissolved by using either soda ash or caustic soda. The latter is preferable, as the former is liable to give a developing bath that froths in working, especially if much acid has been left in the cotton from the diazotising bath. The proportions are: 10 lb. resorcine, 25 lb.
caustic soda lye of 70 Tw., and 60 gallons of water; or 10 lb.
resorcine, 20 lb. soda ash, and 60 gallons of water, heated until a solution is obtained. In the developing bath 1 per cent. of resorcine is usually sufficient to use. It develops an orange with Primuline.
Developer F (Bayer) is a mixture of resorcine and soda ash. It requires 1-1/2 per cent, to make a developing bath.
=Phenol=, better known as carbolic acid, finds a use as a developer. It is dissolved in caustic soda, 10 lb. phenol, 15 lb. caustic soda lye of 70 Tw., and 60 gallons of water. Generally 1 per cent. is sufficient to use as a developer. It is often called yellow developer.
=Naphthylamine ether= is used as a developer for blues in conjunction with the Diamine blacks. It is prepared for use by dissolving in hydrochloric acid, 10 lb. naphthylamine ether powder heated with 5 lb.
hydrochloric acid and 50 gallons water. About 1-1/4 per cent. is required to form a developing bath. Naphthylamine ether is also sent out in the form of a paste mixed with acid, and containing about 25 per cent. of the actual developer.
=Fast blue developer A D= (Cassella), is amidodiphenylamine. It is insoluble in water, but soluble in dilute acid, 10 lb. fast blue developer A D, 5 lb. hydrochloric acid and 35 gallons of water making the bath. To develop full shades 1 to 1-1/2 per cent, is required.
=Blue developer A N= (Cassella). The base of this is insoluble in water, but dissolves in soda, and is probably a naphthol-sulpho acid. The product, as met with in the market, is soluble in water, and 27 lb.
dissolved in 20 gallons of water form the bath. To produce full shades 1-1/2 per cent, is usually required.
=Phenylene diamine= is a most important developer. It comes into the market in two forms, as a powder, very nearly pure, made into a solution by dissolving 10 lb. with 20 gallons of water and 5 lb. hydrochloric acid, and as a solution prepared ready for use. Developer C (Bayer) and developer E (Bayer) are preparations of diamine, the former in a powder, the latter in a solution. Phenylene diamine can be used with the addition to the developing bath of acetic acid or soda.
=Schaeffer's acid= is a sulpho acid of beta-naphthol, and is dissolved by taking 10 lb. of the acid and 7-1/2 lb. soda, boiling with 50 gallons of water. About 1-1/4 per cent. is required for developing full shades.
Developer B (Bayer) is ethyl beta-naphthylamine, in the form of its hydrochloric acid compound. The bath is made from 10 lb. of the developer and 50 gallons of water, 1-1/4 per cent. being used to obtain full shades.
Developer D (Bayer) is dioxy-naphthalene-sulpho acid, and simply requires dissolving in water to make the bath.
=Toluylene diamine= is a homologue of phenylene diamine and is used in precisely the same way.
Generally the special developers issued by the various colour firms simply require dissolving in water to form the developing bath.
The cotton, previously being passed through the diazotising bath, is then run into the developing bath, in which it is kept for from twenty to thirty minutes or until the required shade is fully developed, after which it is taken out, rinsed and dried. The method of working is the same for all the developers, and may be carried out in any kind of vessels. As is indicated above, the developing baths may be kept standing and be freshened up as required; they are used cold. Sometimes two developers are mixed together, in which case care should be taken that an alkaline developer naphthol or phenol be not mixed with an acid developer (phenylene diamine, naphthylamine, etc.), unless the acidity of the latter has been neutralised with soda; otherwise the developer might be thrown out of the bath in an insoluble and hence useless form.
The advantages of the diazotising and developing process just described may be summed as--easy and quick working, superior fastness to washing, soaping and milling, increased fastness to light and softness of the dyed fibre.
_Scarlet._--Dye with 3 lb. Primuline and 20 lb. salt, at the boil for one hour, diazotise and develop with beta-naphthol.
_Crimson._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise and develop with alpha-naphthol.
_Red Brown._--Dye with 4 lb. Primuline and 20 lb. salt, then diazotise and develop with phenylene diamine.
_Deep Orange._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise and develop with resorcine.
_Pale Orange._--Dye with 3 lb. Primuline and 20 lb. salt, then diazotise and develop with phenol.
_Sage Brown._--Dye with 6 lb. Primuline, 3 lb. Titan ingrain blue and 20 lb. salt, then diazotise and develop with resorcine.
_Dark Maroon._--Dye with 6 lb. Primuline, 3 lb. Titan ingrain blue and 20 lb. salt, then diazotise and develop with beta-naphthol.
_Dark Crimson._--Dye with 5-3/4 lb. Primuline, 1/4 lb. Titan ingrain blue and 20 lb. salt, then diazotise and develop with beta-naphthol.
_Dark Blue._--Dye with 3 lb. Zambesi blue B X, 2 lb. soda and 20 lb.
Glauber's salt, then diazotise and develop with amidonaphthol ether.
_Dark Brown._--Dye with 8 lb. Zambesi brown 2 G, 2 lb. soda and 20 lb.
Glauber's salt, then diazotise and develop with toluylene diamine.
_Blue Black._--Dye with 4 lb. Zambesi blue B X, 2 lb. Zambesi black D, 2 lb. soda and 20 lb. salt, then diazotise and develop with 3/4 lb.
toluylene diamine and 1/2 lb. beta-naphthol.
_Red._--Dye with 4-1/2 lb. Primuline, 1/2 lb. Diamine fast yellow A and 20 lb. salt, then diazotise and develop with beta-naphthol.
_Dark Brown._--Dye with 4 lb. Primuline, 1 lb. Diamine azo blue R R, and 20 lb. salt, then diazotise and develop with beta-napthol.
_Deep Chestnut Brown._--Dye with 5 lb. Diamine cutch, 1 lb. soda and 20 lb. Glauber's salt, then diazotise and develop by passing for twenty minutes in a boiling bath of soda.
_Dark Brown._--Dye with 4 lb. Diamine cutch, 1 lb. Diamine black B H, 2 lb. soda and 20 lb. Glauber's salt, then diazotise and develop with phenol.
_Black Brown._--Dye with 1 lb. Diamine brown M, 1-1/2 lb. Primuline, 1 oz. Diamine black B H, 2 lb. soda and 20 lb. Glauber's salt, then diazotise and develop with phenylene diamine.
_Blue._--Dye with 2 lb. Diaminogene blue B B, 1/2 lb. soda and 20 lb.
Glauber's salt, then diazotise and develop with beta-naphthol. A dark blue is got by using 8 lb. of Diaminogene blue B B in the same way.
_Dark Blue._--Prepare the dye-bath with 1-1/2 lb. Diaminogene blue B B, 1-1/10 lb. Diamine azo blue R R, 2 lb. soda and 20 lb. Glauber's salt.
Dye at the boil for one hour, rinse slightly in cold water, then enter into a fresh cold bath prepared with 4 lb nitrite of soda previously dissolved in water, and 12-1/2 lb. hydrochloric acid. For subsequent lots in the same bath one-third of these additions is sufficient. After diazotising rinse the goods in a bath weakly acidulated with hydrochloric or sulphuric acid, and then immediately develop with beta-naphthol.
_Black._--Prepare the dye-bath with 3 lb. Triamine black B, 15 lb.
Glauber's salt, in fifty gallons of water. Dye exactly as in the preceding recipe. Wash and rinse very thoroughly after lifting, then diazotise in a bath of about 250 gallons of cold water, to which add separately 2-1/2 lb. sodium nitrite dissolved in five times its bulk of water and 8 lb. hydrochloric acid diluted. Enter the damp cotton and treat it for about half an hour. Lift, pass through a weak acid bath, rinse, and develop immediately in a bath of about 250 gallons of cold water, containing 1 lb. developer T, 1 lb. soda, previously dissolved together in hot water. Enter the damp goods, work well for half an hour, then lift, wash and dry.
_Blue Black._--Dye with 4 lb. Diamine black B H, 2 lb. soda and 10 lb.
Glauber's salt, then diazotise and develop with naphthylamine ether.
_Dark Navy._--Dye with 3 lb. Diamine azo blue R R, 2 lb. soda and 10 lb.
Glauber's salt, then diazotise and develop with beta-naphthol.
_Light Chestnut Brown._--Dye with 2 lb. Cotton brown N, 1 lb. diamine fast yellow A, 1 lb. soda and 10 lb. salt, then diazotise and develop with phenylene diamine.
_Dark Brown._--Dye with 5 lb. Diamine cutch, 3 lb. soda and 20 lb.
Glauber's salt, then diazotise and develop with fast blue developer A D.
_Black._--Dye with 4 lb. Diamine black B H, 3 lb. soda and 20 lb.
Glauber's salt, diazotise and develop with 2 lb. resorcine and 1 lb.
phenylene diamine.
_Blue Black._--Dye with 4 lb. Diaminogene B, 2 lb. soda and 20 lb.
Glauber's salt, then diazotise and develop with beta-naphthol.
_Black._--Dye with 4-1/2 lb. Diaminogene B, 1/2 oz. Diamine fast yellow B, 3 lb. soda and 20 lb. Glauber's salt, then diazotise and develop with 3 lb. resorcine and 1 lb. phenylene diamine.