Disperse dye - techintroduce

structure

small molecules disperse dye, a water-soluble free radical structure, by means of a dispersant uniformly dispersed in the dye liquor and dyeing. It dyeing polyester fibers, cellulose acetate fibers and polyamide fibers, polyester became special dyes.

can be divided into Disperse Orange dyes, Disperse Blue, Disperse Yellow, Disperse Red composition, can be carried out with several different dyes certain proportion, to obtain a black dispersion, Disperse Green, etc. Disperse Violet disperse dyes.

disperse in the process of product processing, in order to make commercial dyes can quickly become uniform and stable dispersion of colloidal suspensions in water, a dye particle fineness must reach about 1 micron, was added in the course of sanding dispersing and wetting agents, disperse dyes and finishing treatment generally sanding, spices, spray drying, packaging components. After treatment to use a lot of processing aids, such as lignin, MF, anti-settling agents (the SOS), anti dusting agents, dispersants NNO, but also add strength dim sodium sulfate.

disperse dyestuff industry is most important and a major categories, does not contain strong water-soluble group, a dispersed state class of nonionic dyeing dyes in the dyeing process. The particle fineness of about 1μm. After production of the original dye, the subject treatment process, comprising a stable crystal form, such as grinding and dispersing agent together commercialization, in order to obtain the dye product. Mainly used for dyeing polyester and blended fabrics. Synthetic fibers can also be used dyeing cellulose acetate, nylon, polypropylene, polyvinyl chloride, acrylic and the like.

Development History

A micro soluble in water, and is highly dispersed state in water by a dispersant action dyes. Disperse dyes containing no water-soluble group, a lower molecular weight, although the molecule containing a polar group (e.g., hydroxyl, amino, hydroxyalkyl, alkylamino, cyano alkylamino, etc.), is still non-ionic dyes. Such dyes after high processing requirements, usually in the presence of a dispersant by the mill, a highly dispersed, stable polymorph prior to use of the particles. The disperse dye is uniform and stable suspension. Disperse dyes in 1922 Baden aniline soda ash produced by the company, mainly used for dyeing polyester fibers and acetate fibers. Which was mainly used for dyeing acetate fibers. After the 1950s with the advent of polyester fibers, gained rapid development and become dye industry category of products.

properties

Disperse simple structure, showing very low solubility in water and a non-ionic state, in order to make the dye is preferably dispersed in a solution, must, in addition to the dye particles are milled 2μm or less, the need to add a lot of dispersants, dye stably dispersed in suspension in the solution.

Operation

Since polyester fibers having hydrophobicity, high crystallinity, and the entire column, and the small fiber microvoids easily expanded wetting characteristics, to make the dye in the form of a monomolecular smoothly into the interior of the dyeing polyester fibers complete, by a conventional method it is difficult to perform, and therefore, requires the use of special staining methods. There are three methods carrier dyeing method, a high temperature and high pressure and high temperature employed method such as hot-melt. These methods take advantage of the different conditions bulking fibers, the voids between the fiber molecule is increased, while adding additives to increase the rate of diffusion of dye molecules, dye molecules constantly being expanded and increased diffuse into the voids of the fibers, with the fibers by the intermolecular attraction and hydrogen bonding fixed, stained polyester complete. Since the disperse dye is extremely low solubility in water, it relies dispersant dye and dye solution composition. To prevent the disperse dye and polyester produced under high temperature and hydrolysis action of an alkali, dyeing disperse dyes often be carried out under mildly acidic conditions.

1. Carrier staining

Disperse dye

carrier dyeing method is heated under normal pressure. It is the use of some chemicals has direct dyes and fibers, when such chemicals into the interior of polyester during dyeing, the dye molecules also brought into, or carried the chemicals known as carrier agent.

on the principle of using a carrier dyeing of polyester in the polyester is between the benzene ring in the aromatic nucleus of the dye molecules larger molecular attraction, a simple polyester capable of adsorbing hydrocarbons, phenols and the like, these chemicals It will become the carrier. Interaction between the polyester support and the polyester molecular relaxed configuration, the fiber gap is increased, and easy access to the interior fiber molecule. And because the carrier itself may have a direct dye molecules and the fiber attractive, not only help dissolve the dye, the dye molecules to the single fiber surface, to increase fiber surface concentration of the dye, and can reduce the surface tension of the fibers, so that movement of the rapid dye molecules into the fiber void area, to improve the diffusion of the dye molecules to promote binding dye and fiber, thereby completing the dyeing step. After dyeing, the use of caustic, the carrier is completely removed. Common carriers are o-phenylphenol, biphenyl, methyl salicylate, because most toxic, harmful to human beings, have been rarely used, it is presented here only for ships.

2. Temperature and high pressure dyeing method

temperature and high pressure dyeing method is carried out at a high temperature under pressure to wet heat state. Dye uptake rate is very slow at less than 100 deg.] C, even in boiling dye bath dyeing, the dyeing rate and dye uptake is not high, it must be pressurized in the following 2atm (2.02 × 105Pa), the temperature can be raised to the dyebath 120 ~ 130 ℃, due to the temperature increase, the segment of the fiber molecule strenuous exercise, transient pore is generated and the more the greater diffusion of the dye molecule at this time is also faster, increasing the rate of diffusion of the dye into the interior of the fiber, dyeing rate of speed until the complete exhaustion dyeing dye.

high temperature high pressure dyeing disperse dyes is an important method for fastness to sublimation of low molecular weight and low-temperature smaller dye species. Such dyes with good levelness, rich ruby color, feel good, high degree of fabric permeability core, is suitable for small-batch, multi-variety production, commonly used in the dyeing of polyester-cotton blended fabric.

high temperature high pressure dyeing disperse dye may be carried out at high temperature and high pressure jet dyeing machine, overflow dyeing machine, Shen Nong suitable dye color, dye pH value is generally controlled at 5 to 6, and phosphoric acid used ammonium dihydrogen pH adjustment. In order to maintain a stable dye bath, dyeing fashion must be added dispersants and high temperature leveling agent.

dyeing machines Dyeing Example:

Dyeing prescription:

Disperse Dyes: X%

High temperature leveling agent: 0.2 ~ 1.0 g / L

diffusing agent: 0.5 ~ 1.0 g / L

acetic acid (98%) 0.5 ~ 1.0 g / L

reduction washing: < / p>

basified 2.0 g / L

hydrosulfite 4.0 g / L

process:

seam fabric dyeing → pretreatment → → washing → reduction → hot water rinsing → dehydration → amorphous spread. Transfection may generally begin at 60 ~ 70 ℃, after about 1h gradually warmed to 130 ℃, dyeing about 1h, then thoroughly washed with water. When reduction clearing dyed in dark, finished dyed color fastness can be maintained.

3. Hotmelt staining

disperse dyeing polyester / cotton fabric dyed with the hot melt method a similar general padding dyeing, first by padding dye line after drying, then further melt processing. Deg.] C 200 is under high temperature, is deposited on the fabric in the form of dye molecules can diffuse into the interior of the single fiber, to complete the dyeing of polyester in a very short period of time. If the cotton blended fabric, by heat treatment to be dipped in a dye cotton in gas phase or in contact transferred to the polyester. Staining melt polyester blended fabric is the main method of dyeing, padding continuous production of oriented, high production efficiency, especially for mass production. Melt staining disadvantage is large area device, while certain conditions of use of the dye, the dye than low utilization of high temperature and pressure process.

melt dyeing process for example as follows (45 × 45 sticks, light blue, 65/35 polyester / cotton textile fine):

(1) Dyeing prescription

Disperse blue 2BLN 1.5g / L.

wetting agents JFC lml / L

diffusing agent 1g / L

3% sodium alginate paste 5 ~ 1Og / L

use, adjusting pH5 ~ 6 with acetic acid or ammonium dihydrogen phosphate.

(2) Process

Padding

(Second Baptist Second rolling, rolling over 65%, rt) → prebaked (8O ~ 120 ℃ ) → melt (180 ~ 210 ℃, 2 ~ 1min) → dye cotton sleeve.

in the high temperature hot melt dyeing must prevent dye-migration produced in prebaking and baking, the hot melt curing disperse phase is an important stage in the transfer to the polyester cotton, dyes according to heat resistance, i.e. the dye sublimation fastness, hot melt select the appropriate temperature and time. In actual dyeing, the dye can not be transferred completely, remains on a portion of the total dye cotton, cotton cause staining, soaping or reduction cleaning can be carried out after dyeing process. If the jacket but also for dyeing cotton portion in the dyeing after the hot melt method can be set after the selected line after transfection process.

The main application

The main purpose is to disperse the polyester fiber (PET) cellulose acetate (diacetate fibers, triacetate fibers) chemical fibers, and polyamide fibers (nylon ) were stained, polyacrylonitrile (acrylic) also have a small application. By disperse dyeing processing chemical fiber textile products, beautiful color, excellent wash fastness, widely used. Because it is insoluble in water, natural fibers of cotton, hemp, wool, silk, no dyeing power, viscose fibers hardly staining, and therefore usually require chemical fiber blend products used in conjunction with other disperse dyes suitable.

prospects

disperse dyes in use there new progress: ① multi-component disperse dyes, usually consisting of two (there are three or four) disperse dyes mixed by a certain percentage , due to the synergistic effect when using the dye to improve the dye uptake. ② transfer printing, the printing ink is made after the disperse dyes, printing on the fabric, then after high temperature dyeing Pressing. This printing process is known as non-aqueous phase, energy saving, time-saving and convenient advantages. ③ disperse dye and a reactive dye mixture, make cotton, viscose and other mixed textile dyeing step in a bath, the dyeing process is simplified, improving the printing quality.