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DIRECT

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Originally appearing in Volume V08, Page 747 of the 1911 Encyclopedia Britannica.

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DIRECT CoLouxs.—The characteristic feature of the dyestuffs belonging to this class is that they dye See also:

cotton " direct "—i.e. without the aid of mordants. Two distinct See also:

SERIES (a Latin word from serere, to join)

series of colouring matters of this See also:

GROUP

group may be distinguished—namely, Direct Cotton See also:

COLOURS, MILITARY

Colours and Sulphide Colours. (a) Direct Cotton Colours.—The colours of this class are frequently called the Substantive Cotton Colours, Benzo Colours, Diamine Colours, See also:

CONGO

Congo Colours. Considered from the chemical point of view, they are mostly See also:

ALKALI

alkali salts of sulphonated tetrazo colours obtained by diazotizing certain diamido .compounds, e.g. See also:

BENZIDINE (DIPARA-DIAMINO-DIPHENYL), NH2

benzidine, diamido-stilbene, &c., and uniting the products thus obtained with various See also:

AMINES

amines or phenols. The first colouring See also:

MATTER

matter of this class was the so-called Congo red, discovered in 1884, and since that See also:

time a very See also:

GREAT

great number have been introduced which yield almost every variety of See also:

COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour. The method of See also:

DYEING (0. Eng. dedgian, dealt ; Mid. Eng. deyen)

dyeing cotton consists in merely boiling the material in a See also:

SOLUTION (from Lat. solvere, to loosen, dissolve)

solution of the dyestuff, when the cotton absorbs and retains the colouring matter by See also:

REASON (Lat. ratio, through French raison)

reason of a See also:

SPECIAL

special natural See also:

affinity. The concentration of the dyebath is of the greatest importance, since the amount of colour taken up by the fibre is in an inverse ratio to the amount of dye liquor See also:

PRESENT

present in the See also:

bath. The addition of I to 3 oz. See also:

SODIUM [symbol Na, from Lat. natrium; atomic weight 23.00 (0=16)]

sodium sulphate and to oz. carbonate of soda per See also:

GALLON

gallon gives deeper colours, since it diminishes the solubility of the colouring matter in the See also:

WATER

water and increases the affinity of the cotton for the colouring matter. An excess of sodium sulphate is to be avoided, otherwise precipitation of the colouring matter and imperfect dyeing result. With many dyestuffs it is preferable to use a to s oz. See also:

SOAP

soap instead of soda. On cotton the dyed colours are usually not very fast to See also:

LIGHT

light, and some are sensitive to alkali or to See also:

ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid, but their most serious defect is that they are not fast to washing, the colour tending to run and stain neighbouring See also:

fibres. Their fastness to light and washing is, however, greatly improved by a See also:

SHORT, FRANCIS JOB (1857– )

short (2 See also:

HOUR

hour) after-treatment with a boiling solution of See also:

COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper sulphate (3 %), with or without the addition of bichromate of potash (I %).

See also:

WOOL, WORSTED AND WOOLLEN MANUFACTURES

Wool and See also:

SILK

silk are dyed with the direct colours either neutral or with the addition of a little acetic acid to the dyebath. On these fibres the dyed colours are usually faster than on cotton to washing, milling and light; some are very fast even to light—e.g. Diamine fast red, chrysophenine, See also:

HESSIAN

Hessian yellow, &c. Many of the Direct Colours are very useful for dyeing See also:

PLAIN (O. Fr. plain, from Lat. plenum)

plain shades on See also:

union fabrics composed of wool and cotton, silk and cotton, or wool and silk. Owing to the facility of their application, they are also very suitable for use as See also:

HOUSEHOLD, ROYAL

household dyes, especially for cotton goods. A few See also:

VEGETABLE

vegetable dyestuffs belong to this class, notably See also:

TURMERIC (from Fr. terre Write, turmeric, Lat. terra merita, deserved, i.e. excellent earth; Skeat suggests that it is a barbarous corruption, perhaps of Arabic karkam, kurkum, saffron or curcuma)

Turmeric, See also:

SAFFRON (Arab. za'faran)

saffron, annatto and See also:

SAFFLOWER (ultimately from the Arabic safra, yellow)

safflower, but they all yield colours which are fugitive to light, and they are now of little importance. Turmeric is the underground See also:

STEM (O. Eng. staefn, stemn, cf. Du. stain, Ger. Stamm, &c., probably related to " staff ")

stem or tuber of Curcuma tinctoria, a plant growing abundantly in the See also:

East Indies. It dyes cotton, wool and silk in a bath acidified with acetic acid or See also:

ALUM

alum, yielding a See also:

bright yellow colour which is turned See also:

brown by alkalis. Saffron consists of the stigmata of the See also:

flower of See also:

CROCUS

Crocus sativus, which is grown in See also:

Austria, See also:

France and See also:

Spain. It dyes a bright See also:

orange-yellow colour. Annatto is the pulpy See also:

mass surrounding the seeds of Bixa orellana, a plant which grows in See also:

South America—e.g. See also:

Brazil, See also:

CAYENNE

Cayenne, &c.

It dyes cotton and silk in an alkaline or soap bath an orange colour, which is turned red by acids. Safflower consists of the dried florets of Carthamus tinctorius, which is grown in the East Indies, See also:

EGYPT

Egypt and See also:

SOUTHERN

southern See also:

EUROPE

Europe. Cotton is dyed a brilliant See also:

PINK

pink colour by working it in a See also:

COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold alkaline (sodium carbonate) See also:

EXTRACT (from Lat. extrahere, to draw out)

extract of the colouring matter, while gradually acidifying the solution with citric acid (See also:

lime-juice). The Direct Colours which are derived from See also:

COAL

coal-See also:

tar products are very numerous indeed; they are largely employed, and occupy a very important position among dyestuffs, The following See also:

list includes the See also:

PRINCIPAL

principal coal-tar colours of this group: Red.—Congo red, brilliant Congo, benzopurpurine, brilliant purpurine, deltapurpurine, diamine See also:

SCARLET

scarlet, diamine fait red, rosazurine, See also:

salmon red, erica, Titan pink, St See also:

Denis red, See also:

COLUMBIA

Columbia red, naphthylene red, Congo rubine, acetopurpurine, dianol red, thiamine See also:

CRIMSON

crimson, geranine, brilliant geranine, Columbia fast scarlet, benzo fast scarlet, thiamine red, diamine See also:

rose, See also:

DONGOLA

Dongola red, rosophenine. Orange.—Congo orange, benzo orange, toluylene orange, See also:

MIKADO (Japanese for " exalted gate ")

mikado orange, brilliant orange, Columbia orange, diamine orange, pyramine orange, benzo fast orange. Yellow.—Chrysamine, cresotin yellow, diamine yellow, See also:

CARBAZOL, C12H9N

carbazol yellow, chrysophenine, Hessian yellow, curcumine yellow, thiazol yellow, thioflavine S, oriol, See also:

MIMOSA (so named from the movements of the leaves in many species which " mimic " animal sensibility)

mimosa yellow, Columbia yellow, cotton yellow, chloramine yellow, direct yellow, diamine fast yellow, diamine See also:

gold, See also:

sun yellow, stilbene yellow, chlorophenine, oxyphenine. See also:

Green.—Benzo See also:

OLIVE (Olea europaea)

olive, Columbia green, benzo green, diamine green, direct green, See also:

DIPHENYL (phenyl benzene), C6H5

diphenyl green, oxamine green, See also:

EBOLI (anc. Eburum)

eboli green. See also:

BLUE (common in different forms to most European languages)

Blue.—Azo blue, benzoazurine, brilliant azurine, sulphon-azurine, diamine blue, benzo See also:

INDIGO (earlier indico, from Lat. indicum, the Indian sub-stance or dye; the Sans. name was niti, from nila, dark blue, and this through Arab. al-nil, annil, gives " aniline ")

indigo blue, benzo See also:

black blue, See also:

Chicago blue, Columbia blue, See also:

ERIE

Erie blue, See also:

ZAMBEZI

Zambezi blue, benzo cyanine, Congo blue, diamine See also:

SKY (M. Eng. skie, cloud; O. Eng. skua, shade; connected with an Indo-European root sku, cover, whence " scum," Lat. obscurus, dark, &c.)

sky blue, brilliant benzo blue, benzo chrome black blue, oxamine blue, diphenyl blue, diamineral blue, diaminogene, benzo fast blue, diazo indigo blue, brilliant chlorazol blue. See also:

VIOLET

Violet.—Hessian See also:

PURPLE

purple, Congo See also:

Corinth, See also:

heliotrope, Congo violet, diamine violet, Hessian violet, See also:

AZO (c. 1150-1230)

azo violet, benzo violet, violet black, diamine See also:

BORDEAUX

Bordeaux, chlorantine See also:

LILAC

lilac, diphenyl violet, triazol violet, Columbia violet. Brown.—Benzo brown, Congo brown, toluylene brown, diamine brown, cotton brown, Hessian brown, terra-See also:

cotta, mikado brown, See also:

CATECHU

catechu brown, wool brown, Columbia brown, Zambezi brown, benzo chrome brown, direct fast brown, direct See also:

BRONZE

bronze brown, chloramine brown, triazol brown, toluylene brown, dianol brown, Crumpsall direct fast brown. Black.—Diamine black, Columbia black, See also:

NYANZA (from the ancient Bantu root word anza, a river or lake)

Nyanza black, Tabora black, Zambezi black, chromanil black, benzo black, benzo fastblack, direct blue black, See also:

PLUTO (IlXoirrwv)

Pluto black, oxydiamine black, diamine See also:

JET (Fr. jais, Ger. Gagat)

jet black, polyphenyl black, union black, triazol black, Titan black, cotton black, oxamine black. See also:

Grey.—Benzo grey, benzo black, azo See also:

MAUVE, ANTON (1838–1888)

mauve, diaminogene, neutral grey.

(b) Sulphide Colours.—These dyestuffs are only suitable for dyeing the vegetable fibres, since they must be applied in a strongly alkaline bath. The dyestuff Cachou de See also:

Laval, discovered in 1873, was the first member of this group, and was obtained by melting a mixture of sodium sulphide and various organic substances—e.g. See also:

BRAN

bran, saw-dust, &c. In See also:

RECENT

recent years numerous other dyestuffs have been added to the list, namely, grey, blue, green, brown, and especially black colours, by submitting certain definite amido compounds of the aromatic series to a similar treatment with sodium sulphide or sodium thiosulphate, and subsequent oxidation. The mode of dyeing with these colours is based on the fact that they are soluble in an alkaline reducing See also:

AGENT (from Lat. agere, to act)

agent, and if the cotton is worked in the solution, subsequent oxidation develops the colour, which is fixed upon the fibre in an insoluble See also:

CONDITION (Lat. condicio, from condicere, to agree upon, arrange; not connected with conditio, from condere, conditum, to put together)

condition. The material is boiled for about one hour in a solution of the colour (to to 15 %), with the addition of sodium carbonate (I to to %), See also:

COMMON

common See also:

salt (To to 20%), and sodium sulphide (5 to 30 %) ; it is then washed in water, and may be See also:

DEVELOPED

developed by See also:

HEATING

heating in a bath containing 2 to 5 % of bichromate of soda, and 3 to 6 % acetic acid. A final washing with water containing a little soda to remove acidity is advisable. The sulphide colours are remarkable for their fastness to light, alkalis, acids and washing, but unless proper care is exercised the cotton is See also:

apt to be tendered on being stored for some time. The following list includes some of the most important of the colours of this class: Yellow.—Immedial yellow, pyrogene yellow, See also:

SULPHUR

sulphur yellow, thion yellow, thiogene yellow. Orange.—Eclipse phosphine, immedial orange, pyrogene orange, thion orange, thiogene orange. Green.—Pyrogene green, See also:

ITALIAN

Italian green, See also:

ECLIPSE (Gr. €uheo,tis, falling out of place, failing)

eclipse green, pyrol green, immedial green, katigene green, thionol green. Blue.—Immedial blue, immedial sky blue, eclipse blue, katigene indigo, pyrogene blue, sulphur blue, thion blue, thiogene blue. Violet.—Katigene violet, thiogene heliotrope, thiogene purple.

Brown.—Pyrogene brown, pyrogene yellow, Cachou de Laval, thiocatechine, katigene black brown, eclipse brown, immedial. brown, katigene brown, dianol brown. Grey and Black.—Pyrogene grey, Vidal black, immedial black, katigene black, See also:

ANTHRAQUINONE, C14H802

anthraquinone black, St Denis black, amidazol black, See also:

CROSS

cross dye black, eclipse black, See also:

CARBIDE

carbide black, thiogene black, sulphaniline black, sulfogene black, pyrogene black, dianol black, sulphur black, thion black, kryogene black. This class of colours is continually increasing in number, and for certain purposes in cotton dyeing the group has acquired great importance.

End of Article: DIRECT

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