Reactive dye
Encyclopedia
In a reactive dye a chromophore
contains a substituent
that is activated and allowed to directly react
to the surface of the substrate. Reactive dyes have good fastness properties owing to the bonding that occurs during dyeing.
Reactive dyes are most commonly used in dyeing of cellulose like cotton or flax, but also wool is dyeable with reactive dyes.
Dyestuffs Division site in Blackley
, Manchester
, United Kingdom
.
heterocycle or an activated double bond, that, when applied to a fibre in an alkaline dye bath, forms a chemical bond
with an hydroxyl
group on the cellulosic fibre.
R = Chromophore
Cell = Cellulose
And trichlorotriazine:
Reactive dyeing is now the most important method for the coloration of cellulosic fibres. Reactive dyes can also be applied on wool
and nylon
; in the latter case they are applied under weakly acidic conditions. Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group also bonds to water, creating hydrolysis
.
Reactive dyes are categorized by functional group.
Dyestuffs containing two groups are also known as bifunctional dyestuffs, though some still refers to the original combination. Other types of bifunctional dyes has been introduced. The first bifunctional dye made where more tolerant to temperature deviations (better process). Other bifunctionals are created, some with fastness (better quality) or only fixation degree (better environment/economy) in mind.
Trifunctional dyestuffs also exist.
Chromophore
A chromophore is the part of a molecule responsible for its color. The color arises when a molecule absorbs certain wavelengths of visible light and transmits or reflects others. The chromophore is a region in the molecule where the energy difference between two different molecular orbitals falls...
contains a substituent
Substituent
In organic chemistry and biochemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon...
that is activated and allowed to directly react
Chemical reaction
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...
to the surface of the substrate. Reactive dyes have good fastness properties owing to the bonding that occurs during dyeing.
Reactive dyes are most commonly used in dyeing of cellulose like cotton or flax, but also wool is dyeable with reactive dyes.
History
Reactive dyes first appeared commercially in 1956, after their invention in 1954 by Rattee and Stephens at the Imperial Chemical IndustriesImperial Chemical Industries
Imperial Chemical Industries was a British chemical company, taken over by AkzoNobel, a Dutch conglomerate, one of the largest chemical producers in the world. In its heyday, ICI was the largest manufacturing company in the British Empire, and commonly regarded as a "bellwether of the British...
Dyestuffs Division site in Blackley
Blackley
Blackley is an area of the city of Manchester, in Greater Manchester, England. It is north of Manchester city centre, by a meander of the River Irk. Further north is Middleton...
, Manchester
Manchester
Manchester is a city and metropolitan borough in Greater Manchester, England. According to the Office for National Statistics, the 2010 mid-year population estimate for Manchester was 498,800. Manchester lies within one of the UK's largest metropolitan areas, the metropolitan county of Greater...
, United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
.
Usage
The dyes contain a reactive group (often trichlorotriazine), either a haloHalogen
The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style of the periodic table, comprising fluorine , chlorine , bromine , iodine , and astatine...
heterocycle or an activated double bond, that, when applied to a fibre in an alkaline dye bath, forms a chemical bond
Chemical bond
A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electromagnetic force attraction between opposite charges, either between electrons and nuclei, or as the result of a dipole attraction...
with an hydroxyl
Hydroxyl
A hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
group on the cellulosic fibre.
R = Chromophore
Cell = Cellulose
And trichlorotriazine:
Reactive dyeing is now the most important method for the coloration of cellulosic fibres. Reactive dyes can also be applied on wool
Wool
Wool is the textile fiber obtained from sheep and certain other animals, including cashmere from goats, mohair from goats, qiviut from muskoxen, vicuña, alpaca, camel from animals in the camel family, and angora from rabbits....
and nylon
Nylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
; in the latter case they are applied under weakly acidic conditions. Reactive dyes have a low utilization degree compared to other types of dyestuff, since the functional group also bonds to water, creating hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
.
Reactive dyes are categorized by functional group.
| Functiona | Fixation | Temperature | Included in Brands |
|---|---|---|---|
| Monochlorotriazine | Haloheterocycle | 80˚ | Basilen E & P Cibacron E Procion Procion Procion is a brand of fibre reactive dyes.Procion MX are a class of cold reactive dyes . They are commonly used in tie dye and other textile crafts. They are dichlorotriazine dyes and were originally made by ICI... H,HE |
| Monofluorochlorotriazine | Haloheterocycle | 40˚ | Cibacron F & C |
| Dichlorotriazine | Haloheterocycle | 30˚ | Basilen M Procion MX |
| Difluorochloropyrimidine | Haloheterocycle | 40˚ | Levafix EA Drimarene K & R |
| Dichloroquinoxaline | Haloheterocycle | 40˚ | Levafix E |
| Trichloropyrimidine | Haloheterocycle | 80-98˚ | Drimarene X & Z Cibacron T |
| Vinyl sulfone | activated double bond | 40˚ | Remazol |
| Vinyl amide | activated double bond | 40˚ | Remazol |
Bifunctional
Dyestuffs with only one functional group sometimes have a low degree of fixation. To overcome this dyestuffs containing two different reactive groups (i.e. one monochlorotriazin and one vinyl sulfone) were created.Dyestuffs containing two groups are also known as bifunctional dyestuffs, though some still refers to the original combination. Other types of bifunctional dyes has been introduced. The first bifunctional dye made where more tolerant to temperature deviations (better process). Other bifunctionals are created, some with fastness (better quality) or only fixation degree (better environment/economy) in mind.
Trifunctional dyestuffs also exist.