Reactive Dyeing Mechanism. Reactive Dyeing Mechanism. Diffusion Factor. Adsorption Factor : Liquor ratio (Liquor-to-material ratio) (C) (B) (A)

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Roderick Booth
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1 Reactive yeing Mechanism Reactive yeing Mechanism Step 1: Adsorption and iffusion - The required amount of dissolved dye is added to the dye bath at ambient temperature and circulated through the goods. - The required amount of salt is added in portions to exhaust the bath. - uring this period, the dye does not react with the fiber and migration from fiber to fiber is possible. Step 1: Adsorption and iffusion Step 2 : Fixation Step 3 : Wash-off - Adsorption and diffusion is controlled by varying the dyeing time, the dyebath temperature and the salt concentration Adsorption Factor : Liquor ratio (Liquor-to-material ratio) iffusion Factor igher liquor ratio gives lower substantivity Exhaustion (%) Time (min) (A) 1:10 (B) 1:20 (C) 1:30 Adsorption Curve (A) (B) (C) Molecular Weight yeing Temperature Electrolyte Relative iffusion Rate 500 (A) (B) (C) Molecular Weight of the yes (A) Cold yeing yes & Continuous yes (B) MCT yes (C) irect yes

Reactive yeing Mechanism Reactive yeing Mechanism Step 2: Fixation : Step 3: Wash-off : - The required amount of alkali is added to the goods with good circulation and fixation proceeds.

2 Reactive yeing Mechanism Reactive yeing Mechanism Step 2: Fixation : Step 3: Wash-off : - The required amount of alkali is added to the goods with good circulation and fixation proceeds. - This produces a system with three Possibilities for neuclophilic reaction with the dye, two in the fiber phase, with the cellulosate and hydroxide ions, one in the dye bath with hydroxide ions At the end of the dyeing stage there might be 75-90% of the color either exhausted or fixed on the fiber - there is 10-25% of hydrolyzed color left in the bath. - f the color on the fiber 15-25% is not fixed but is held by substantivity only; 50-75% of the reactive dye added to the bath initially is covalently bonded to the fiber. 74 Reactive yeing Mechanism Reactive yeing Mechanism Step 3: Wash-off : Step 3: Wash-off : - igh substantivity of the hydrolyzed dyes gives poor wash-off properties and therefore poor fastness External aqueous dyebath ye- ye ydrolyzed in the bath - the hydrolyzed reactive dyes have the similar chemical structure with direct dyes which has a substantivity towards cellulosic fibers (planar, van der Waals forces) a 3 S S 3 a a 3 S S 3 a Fiber ye- ye- ye-- ye-- ye- ye ydrolyzed inside the fiber 2 C 2 C 3 C 2 C C 3 2 C 2 C ye- Principle of direct dyeing of cellulose 75 76

3 Reactive yeing Mechanism Strategies to Avoid ydrolysis Step 3 : Washing ff : Cold water wash at approximately 25 to 60C ot water wash at approximately 60 to 80C Scouring with Anionic Surfactant at 80 to 90C ot and Cold Water Washing - The washing off process is lengthy but unavoidable. To achieve the high wet fastness accepted from a fiber reactive dyeing all the hydrolyzed and unfixed dye has to be removed. - The more substantive the hydrolyzed dye, the more difficult it will be to remove and it could continue to bleed slowly overtime. 1) The ratio of K R /K is a property of individual dye molecules and is out of the hands of the dyer. 2) The p is kept below 11, increasing the salt concentration can raise the value of [Cell- - ] f / [ - ] f. owever the amount of salt suggested by the manufacturer is usually the optimum for the particular procedure. 3) Finally the traditional batch dyeing method of salting of the dye and only then adding alkali should have the hydrolysis of dye in solution. Increasing the substantivity of existing dyes by increasing the recommended salt additions or lowering the recommended temperature might be effective Strategies to Avoid ydrolysis Reactive ye- Monofunctional 40 C 4) Salt addition may decrease the rate of dye diffusion and increase the possibility of dye aggregation, even induce perception, while adding to the effluent problem. 5) There are some benefits from lowering the liquor ratios, which would increase substantivity although the salt may have to be reduced to avoid aggregation or solubility problems. 80 C 60 C Aminochlorotriazine : Procion (Zeneca) 40 C Vinylsulphone(Sulphatoethylsulphone) : Remazol (E) Sumifix (K) Aminofluorotriazine : Cibacron F (Ciba) 79 80

Reactive ye- Monofunctional Reactive ye- Bifunctional 40 C ichloroquinoxaline : Levavix E (Bayer) 80 C 40 C Bis-Amoniochlorotriazine : Procion -E (Zeneca) Bis-icotinotriazine : Kayacelon React (KYK)

4 Reactive ye- Monofunctional Reactive ye- Bifunctional 40 C ichloroquinoxaline : Levavix E (Bayer) 80 C 40 C Bis-Amoniochlorotriazine : Procion -E (Zeneca) Bis-icotinotriazine : Kayacelon React (KYK) Trichloropyrimidine : rimarene X (Sandoz) Chlorodifluoropyrimidine : rimarene K (Sandoz) Aminochlorotriazine-vinylsulphone : Sumifix supra (SK) Aminoflulorotriazine-vinylsulphone : Cibacron C (Ciba) assification of Reactive yes Reactive ye 의역사 - 구조 / 반응온도 / 용도 83 84

5 Cell R R Cell Cell R Cell S2 substitution of monochlorotriazine type reactive dyes S C C Cell S C C 2 S a Cell S C C + a 2S S C C Cell S C C Cell ucleophilic addition of vinylsulphone type reactive dyes Chemistry of Reactive yes yestuff Research Vinyl Sulfonates : - These reactive groups are normally transients and are masked by water Solubilizing leaving groups and their name is abbreviated to (VS). - Vinyl sulfone groups are actually written: -S 2 C=C 2, but this group is rarely if ever found in a reactive dye product. Generally the functional group: -S 2 C 2 C 2 S 3- ( + or a + ) ye MCT These include generally low efficiency of fixation with its resulting highly colored waste and the large amount of salt needed. R ye S 2 C=C 2 VS - The bridging group (B) is the sulfone,-s 2 -, portion of the structure which withdraws electrons from the rest of the group so that in the presence of alkali the leaving group (X) departs with hydrogen ion and unmasks the hidden vinyl group: S= Substantivity E= Exhaustion F= Fixation -S 2 C 2 C 2 S 3 - S 2 C=C 2 + S

6 Bifunctional Reactive yes A few dyes with two reactive groups have been known for about 30 years. Chrom R R S 2 -C=C 2 MCT-VS Bi-functional reactive dyes are made because of increasing the solubility, substantivity, salt sensitivity, rate of sorption and rate of diffusion. Bifunctional Reactive yes Sulphetoethylsulphonyl group a 3 S 2 C 2 C 2 S a 3 S 2 C 2 C 2 S a 3 S 2 C 2 C 2 S 2 Sumitomo Japanese Patent Chromogen- 2 Chromogen Bifunctional Reactive yes Bifunctional Reactive yes A or A o m p S or VS S or VS S or VS S : -S 3 a VS : -S 2 C 2 C 2 S 3 a Seven possibilities for A, A in bi and poly functional reactive dyes A a 3 S S 3 a 1 4 a 3 S S 3 a A' A a 3 S S 3 a C A C A A' These limited options give the possibility of different red, mono, di or tri functional reactive dyes all of which can be represented by the general formula A C A A-C-B-C-A If two segments A-C- are joined by group B- (which may be a benzene ring attached at both ends in the 1 and 4 positions) an additional seven symmetrical red bi- and Polyfunctional dyes can be added. All these dyes have the general formula A-C-B-C-A

Bifunctional Reactive yes Advantages of Bifunctional and Polyfunctional Reactive dyes Exhaustion(%) curves : MCT vs VS vs Bifunctional Probability of Fixation : ex.

7 Bifunctional Reactive yes Advantages of Bifunctional and Polyfunctional Reactive dyes Exhaustion(%) curves : MCT vs VS vs Bifunctional Probability of Fixation : ex. Mono functional reactive dyes : 60% Bifunctional reactive dyes : 84%. Trifunctional reactive dyes : 91% Monochlorotriazine Relative Strength(%) Bifunction Vinyl sulfone Inorganic Salt Alkali yeing Time(min.) Migration property : evaluation methods Migration property : evaluation methods Bifunctional type MCT type yeing depth : 3.0% o. w. f. Glauber s salt : 50g/l Liquor ratio : 1:20 Temperature and time : 60, 20min 95 96

Migration property : evaluation methods Migration potential - ye which is not fixed can migrate.

- nce a dye molecule has become fixed to a particular site on the cellulose, it cannot physically move in any direction.

ye- ye- ye-- ye-- ye- Migration% = (B2/2)X100 97 98 Migration potential ; Premature fixation Wash fastness Premature fixation, can easily be caused by : - incomplete rinsing of

8 Migration property : evaluation methods Migration potential - ye which is not fixed can migrate. - But if dye is in the external dyebath, then any migration within the solution cannot contribute to the levelling process. - nce a dye molecule has become fixed to a particular site on the cellulose, it cannot physically move in any direction. In order for migration to effectively contribute to levelling, it must : - be within the fiber - not be in the bath - not be hydrolyzed -not be fixed to the fiber. ye- ye- ye-- ye-- ye- Migration% = (B2/2)X Migration potential ; Premature fixation Wash fastness Premature fixation, can easily be caused by : - incomplete rinsing of fiber after preparation -the presence of bicarbonate in the dyehouse water. Both cases are often found in practice, and the dangers are : Before laundering After laundering - loss of yield from a given dye recipe, and therefore reduced economy - unexpectedly low wet fastness for a given dye selection - unlevel dyeing - poor shade reproducibility. FSL, FXL, FGL WL, GXL(), BSL

Colorfastness to perspiration and light 101 Light fading mechanism of

5a3SC24S23C2S3aa3Sa3SC24S23C2S3aa3S..hv.a3SC24S23C2S3aa3S.a3SC24S23C2S3aa3S..a3SC24S23Ca3SS3a2.

9 Colorfastness to perspiration and light 101 Light fading mechanism of reactive dyes Red Light fastness = 2 Blue Light fastness = 5a3SC24S23C2S3aa3Sa3SC24S23C2S3aa3S..hv.a3SC24S23C2S3aa3S.a3SC24S23C2S3aa3S..a3SC24S23Ca3SS3a2.a3SC24S23C2S3aa3SCu102 Red Light fastness = 2 Blue Light fastness = 5 a3sc24s23c2s3aa3sa3sc24s23c2s3aa3scurcc2-a3sc24s23c2s3aa3scurcc2-perspiration(amino acid)rcc2-r2cc-cu+ Metal complex with amino acid 103 Perspiration-Light fading mechanism of reactive dyes 염소수견뢰도 Brown 원포변퇴포 live Brown live Burgundy 색차 (65) Sunzol S Sunfix Supra Suncion -E VS BF MCT VS BF MCT 반응성염료의견뢰도 104

Disperse dyes. Disperse dyes. Disperse dyeing process. Disperse dyeing mechanism. Dye solid. Dye micelles. Dye fiber. Disperse Dyeing Mechanism.

Disperse dyes. Disperse dyes. Disperse dyeing process. Disperse dyeing mechanism. Dye solid. Dye micelles. Dye fiber. Disperse Dyeing Mechanism. Disperse dyes Disperse dyes - Disperse dyes are nonionic, have very limited solubility in water at room temperature - They have substantivity for one or more hydrophobic fibers e.g. Polyesters, cellulose