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Concept of dyes
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Dyes refer to colored organic compounds that can obtain colour and lustre from fiber materials, but not all colored organic compounds can be used as dyes. As dyes, there are generally four conditions.
One
chroma
It must be able to dye a certain concentration of color (with a certain rate of dye enhancement).
Two
Coloring ability
That is to say, it has a certain binding force with textile materials, that is affinity or immediacy.
Three
Solubility
That is, it can be dissolved directly in water or dissolved in water by chemical action.
Four
color fastness
That is to say, the colors dyed on textile materials need to be durable and not easy to fade or discolor.
Some colored materials are insoluble in water, have no affinity for fibers and can not be included in the fibers, but they can be mechanically fixed on the fabric by the action of adhesives, which become pigments. Coatings can be prepared by grinding pigments and dispersants, moisture absorbents and water. Coatings can also be used for dyeing, but they are not widely used in printing.
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Development and classification of dyes
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In 1857, W. H. Perkin of Britain industrialized its aniline violet dye, which was the first synthetic dye.
Dyestuff production generally takes 1857 as the demarcation line: before 1857, it is the extraction and processing stage of natural dyes; after 1857, it is the production and processing stage of synthetic dyes.
According to the Dye Index, there are more than 7000 synthetic dyes (including organic pigments) in the world, and more than 2000 kinds of synthetic dyes are often produced. Although synthetic dyes are only 160 years old, they are developing at an amazing speed.
Classification of dyes
There are two kinds of classification methods for dyes. One is to classify dyes according to their properties and application methods, and the other is to classify dyes according to their chemical structure or characteristic groups, which is called chemical classification.
1 Classification by chemical structure
It can be divided into azo dyes, anthraquinone dyes, aromatic methane dyes, indigo dyes, sulfur dyes, phthalocyanine dyes, nitro and nitroso dyes. In addition, there are other types of dyes, such as methyl and polymethyl dyes, stilbene dyes and various heterocyclic dyes.
2 classification by application
Divided into: direct dyes, acid dyes, cationic dyes, reactive dyes, insoluble azo dyes, disperse dyes, VAT dyes, sulfur dyes, polycondensation dyes, fluorescent whitening agents, in addition, there are oxidizing dyes (such as aniline black), solvent dyes, polypropylene dyes and edible colors for food. Su and so on.
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Nomenclature of dyes
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There are many kinds of dyes. In order to meet the requirements of production and application, the proper color and application performance of reactive dyes must be given a special name for dyes.
According to the Draft Nomenclature of Dyestuff Products, which was piloted by the Ministry of Chemical Industry of China since January 1965, the nomenclature of dyestuffs in China, mdash; & mdash; three-stage nomenclature, is introduced as follows: the nomenclature of dyestuffs consists of three parts, namely, & ldquo; & ldquo; & rdquo; & ldquo; & rdquo; & ldquo; & ldquo; & rdquo;.
The Title part is mdash; & mdash; which denotes the application category of dyes, the commodity name or application category of dyes in the world denotes the title of dyes, and the application category or property of dyes is used as the title in China.
There are 31 kinds of dye crowns in China, such as acid, acid complexation, acid medium, neutral, direct, direct sunproof, direct blending, alkali, cation, activity, reduction, soluble reduction, sulfur, sulfur reduction, dispersion, chromophenol, chromophore, salt, condensation polycondensation, fast pigments, etc.
The color part is — — the color of dye on the fiber is basically the same at home and abroad.
Twenty-nine color names are used: tender yellow, yellow, golden yellow, dark yellow, orange, bright red, red, peach red, rose red, magenta, red purple, jujube red, purple, Turquoise blue, blue, Lake blue, brilliant blue, dark blue, green, brilliant green, dark green, yellow brown, brown, dark brown, olive green, grass green, grey, black.
The adjectives of color are &ldquo, Nen &rdquo, &ldquo, &rdquo, &ldquo, deep &rdquo, three words.
The suffix - mdash; & mdash; that is to say, the color, shape, special properties and other dyeing properties are explained by certain symbols and figures.
Commonly used symbols and their meaning enumerated
(1) the quality of dyestuff or color.
The customary name of A dye is code name, such as lake blue A, acid scarlet A.
B indicates blue light or blue light .
G indicates yellow or green light.
R indicates red light .
F means pure color .
D indicates dark or darker shade.
… … … …
Presentation of properties and uses
AS insoluble azo dye naphthol series, such as AS-D, etc.
B double three azine dyes, such as Megafix golden yellow BES
C indicates chlorine resistance, such as reducing blue BC, cotton, insoluble azo dye hydrochloride.Such as yellow base GC.
D is suitable for dyeing and high temperature resistant blended direct dyes, such as direct blending yellow D-RL, and high temperature disperse dyes, such as Dispersol orange D-G, can print VAT dyes, such as reduced brown RRD.
… … … …
The suffix of the dye force fraction.
Dyestuff ends are often expressed in dye end notes, such as 100%, 200%, etc. The so-called dye force refers to the relative concentration determined by the dye manufacturer with a certain mass fraction as the dye force standard (force as 100%). For example, 50% is a dye whose strength is half of the standard dye. Different manufacturers have different standards of strength. Dyestuff factories often add fillers such as dyeing promoters, diffusives, cosolvents and other additives to the dyes. Attention should be paid to the use of these additives.
Illustrating
Reactive Brilliant Red M-8B 150%, & ldquo; Reactive & rdquo; & ldquo; denotes reactive dyes as title; & ldquo; Brilliant Red & rdquo; denotes bright red after dyeing textile materials; & ldquo; M-8B 150%& rdquo; is the end of the word, & ldquo; M” refers to M-type reactive dyes, & ldquo; B” refers to the color and light of dyes. Blue, & ldquo; 8B” refers to the ratio of & ldquo; B” a lot of blue, indicating that this is a red dye with heavy blue light, & ldquo; 150% & rdquo; indicating the strength or strength of the dye.
