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

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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.

- In the aqueous solution from which dyeing normally takes place, despite the low water solubility of the dye.

1 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 acetate and ylons. - They are usually applied from a fine aqueous dispersion containing some dissolved dye. - In the aqueous solution from which dyeing normally takes place, despite the low water solubility of the dye. Disperse Red 1 Disperse Red 60 2 Brown 3% Viloet range8% 8% Blue 30% - It reflects the difficulty of synthesizing green and black compounds, which are nonionic and of small enough molecular size to have substantivity for and to be able to diffuse into hydrophobic fibers. Disperse dyeing mechanism Disperse Dyeing Mechanism Disperse dyeing process Disperse dyeing recipe Dy e Dispersing agent Dye solid Dye micelles Dye dissolved (0.1mg/L) Dye fiber - Disperse dye : x(%owf) - p control agents : p with acetic acid(0.4g/l) - Dispersing agent : 0.5g/l A general thumb rule has the starting temperature about 70-80C. 30 C 70~80 C 2 0 C/min Dye, PET, Dispersing agent, p control agent 130 C,60 min 3 C/min 40 C Reduction clearing Chap4-81 Chap4-82 Chap4-83 Chap4-84

Disperse dyeing process Disperse dyeing process Reduction Clearing (R/C) Recipe 80 C, 20min Chap4-86 Reduction Clearing(R/C) of dyed Polyester onpenetrated dyes Staining 2 0 C/min 40 C Penetrated

2 Disperse dyeing process Disperse dyeing process Reduction Clearing (R/C) Recipe 80 C, 20min Chap4-86 Reduction Clearing(R/C) of dyed Polyester onpenetrated dyes Staining 2 0 C/min 40 C Penetrated dyes 80 o C, 20min - Caustic Soda(a) : 2g/l - Sodium ydrosulfite (a 2 S 2 4 ) : 2 g/l - Soaping agents : 2 g/l Wash off o staining Chap4-85 Disperse dyeing process Principles of reduction clearing Disperse dyeing process Phase of exhaust dyeing of polyester Azo dyes R 4 R 6 Reduction R 1 R 1 2 R 7 a 2 S 2 4, a R 5 Anthraquinone dyes 2 R 5 R 4 R 6 R 7 Colorless / o substantivity for PET The heating or adsorption phase is the most critical in determining the levelness of the dyed fiber Molecular diffusion into the fiber, is the ratedetermining step The dyed polyester is cleared of surfacedeposited dye by means of treatment with reductive treatments R 8 R 5 R 4 a + R 1 R 8 - R 1 Reduction Clearing xidation R 5 - R 4 a + Solubilized leuco form cf. Anthraquinone dyes is partially and reversibly reduced to a soluble sodium leuco form which can be washed away Chap4-87 Chap4-88

Batch dyeing machines Reactive dyeing process Round type Tube type - Liquor ratio (liquor-to-goods ratio):. i.e. 50:1 = 50Kg dyebath : 1 Kg textile.

dyeings in small batches (immersing the goods in one vessel) - Batchwise process:.

higher the liquor ratio, the higher is the substantivity required to produce a good color yield Chap4-89 Chap4-90 Chemical structures of disperse dyes

found suitable for disperse dyes are : Mono Azo Dyes Anthraquinoid Derivatives eterocyclic Compounds R X X R The largest majority (50%) of disperse

3 Batch dyeing machines Reactive dyeing process Round type Tube type - Liquor ratio (liquor-to-goods ratio):. i.e. 50:1 = 50Kg dyebath : 1 Kg textile. higher the liquor ratio, the higher is the substantivity required to produce a good color yield - Batchwise process:. dyeings in small batches (immersing the goods in one vessel) - Batchwise process:. dyeings in small batches (immersing the goods in one vessel) - Liquor ratio (liquor-to-goods ratio):. i.e. 50:1 = 50Kg dyebath : 1 Kg textile. higher the liquor ratio, the higher is the substantivity required to produce a good color yield Chap4-89 Chap4-90 Chemical structures of disperse dyes Disperse Dyes Chemical structures of disperse dyes Some of the remaining dyes are unique chemical entities and among the variety of structural type found suitable for disperse dyes are : Mono Azo Dyes Anthraquinoid Derivatives eterocyclic Compounds R X X R The largest majority (50%) of disperse dyes are mono azo dyes of relatively low molecular weights. They contain no ionic Solubilizing groups in dye bath conditions. They may be quite strongly polar. A significant proportion (20%)of the remaining disperse dyes are Anthraquinoid derivatives, but they are being gradually replaced (except for some bright pinks and blues) because of cost and environmental problems in manufacture. ewer disperse dyes are increasingly based on the use of heterocyclic compounds. Benzodifuranones Coumarins Methines R 1 aphthalimides itrodiphenylamines Quinophthlones Chap4-91 Chap4-92

4 Monoazo dyes Monoazo dyes R 1 R 4 = R 6 R 7 Diazo Component - It does not extend to bright blues, greens or blacks. - The brighter and greener shades of yellow are well covered by the heterocyclic azo and other possible chromophores. R 5 Coupling Component Dye R 1 R 4 R 5 R 6 R 7 Yellow range 3 2 range30 2 Cl Cl C 2 4 C C 2 4 Ac Red 1 2 C 2 5 C 2 4 Red 13 2 Cl C 2 5 C 2 4 Red S 2 C 3 C 3 C 2 4 Ac C 2 4 Ac Yellow 3 Ac C The hydroxy group imparts better light fastness to dyeing on acetate and polyester than corresponding amino group. - The same hydroxy group has the reverse effect on nylon dyeings. Chap4-93 Chap4-94 Anthraquinonoid dyes Anthraquinonoid dyes - The hue is almost totally controlled by substituents R 1,R 4, R 5 and R 8 and these substituents are usually hydroxy, amino and secondary amino groups R. - Substituents and positions have less effect on the hue of the AQ disperse dyes but can have considerable effect on the dyeing and fastness properties of the product. - The substituent (R) in the secondary amino group can be: - C 3,-C 2 4, a benzene ring(ar), or a benzene ring which is itself substituted with a methoxy (-C 3 ) group or hydroxy ethyl group C 2 4 at the para position. - While yellow and orange products based on anthraquinone can be synthesized they have not proved to be competitive with yellow and orange disperse dyes based on other chromophores. - As a result most surviving AQ disperse dyes are bright reds, through violets to blues. Chap4-95 Chap4-96

5 Anthraquinonoid dyes R 1 R 8 R 5 R 4 Dye ame R 1 R 4 R 5 R 8 1 range 2 Red Red 9 C 3 4 Red 60 2 Ar 5 Violet Blue Blue 14 C 3 C 3 ther dye chromophores - The aminoazobenzene derivatives do not extend into the area of greenish yellows. Although they are often economical and show high extinction coefficients, they are not noted for their brightness. - The derivatives of Anthraquinone suitable for bright greenish yellows can be synthesized, but there are other more cost effective alternatives because AQ dyes generally have much lower extinction coefficients than azo dyes. Benzodifuranes : - Derivatives of a recently introduced X heterocyclic Chromophore boast a R bright red disperse dye of very high X extinction coefficient. - ues range from yellow to blue. Benzodifuranones R Chap4-97 Chap4-98 ther dye chromophores ther dye chromophores Coumarins: - Principally bright fluorescent yellows, C.I. Disperse yellow Some derivatives are used as a fluorescent brighteners. Coumarins itrodiphenylamines: - Chemically simple, economical yellows of high light fastness on polyester but of low extinction coefficient. - They have poor light fastness on nylon. itrodiphenylamines Methines: - Although mainly featured in brilliant yellows, C.I Disperse Yellows 49,82,92 the group includes the brightest blue disperse dye currently available. aphthalimides: - This group includes some brilliant, fluorescent compounds example C.I Disperse Yellow 11. Methines R 1 aphthalimides Quinophthalones: - The unsubstituted parent compound C.I Disperse Yellow 54 is a low energy dye suitable for many general applications along with C.I Disperse Red 60 and C.I disperse Blue C.I Disperse Yellow 64 and 67 have higher energy and have better resistance to sublimation. Quinophthalones Chap4-99 Chap4-100

ther dye chromophores The heterocyclic diazo components and coupling components which have been used to improve the brightness and color range of mono azo disperse dyes.

Diazo Component Coupling Component - The coupling component conventionally drawn at the right hand side, contains groups which tend to donate electrons such as the substituted amino groups,-(r 6 )R 7.

6 ther dye chromophores The heterocyclic diazo components and coupling components which have been used to improve the brightness and color range of mono azo disperse dyes. Azothiophenes : - These range from C.I. Disperse Blue 284 to the only available Disperse Green, C.I Disperse green 9. Azobenzohiazoles : - oteworthy for scarlets through bordeaux reds - C.I Disperse Reds 153,177,263. R 1 Azothiophenes S = Azobenzothiazoles R 4 Azo Disperse Dyes ther dye chromophores - The Diazo component side of the molecule normally contains the groups tending to attract electrons R 1. Diazo Component Coupling Component - The coupling component conventionally drawn at the right hand side, contains groups which tend to donate electrons such as the substituted amino groups,-(r 6 )R 7. R 1 R 4 R 6 = R 7 R 5 Azopyridones: - ften used for bright yellows - C.I. Disperse Yellow 119 Azopyridones Chap4-101 Chap4-102 Color and constitution in dyes Substitution Effects Color and constitution in dyes Azo Disperse Dyes Excited State X Excited State R 1 + Yellow range E E 1 E 2 E = hc/ Red Bathochromic Shift (Increase in the wavelength of maximum absorption by the dye, Red shift) Ground State E 1 > E 2, 1 < 2 X Ground State Bathochromic shift : to longer wavelength Violet Blue Green The greater the tendency of groups at the left side of the azo group to accept electrons and the groups at the right hand side to donate electrons the further move the molecule is called Bathochromic shift. (cf. ypsochromic shift) Ṅ. R1 Chap4-103 Chap4-104

7 Color and constitution in dyes Color and constitution in dyes Azo Disperse Dyes Anthraquinone Disperse Dyes Dye ame R 1 R 4 R 5 R 6 R 7 1 Yellow 2 range range30 2 Cl Cl C 2 4 C C 2 4 Ac 4 Red 1 2 C 2 5 C Red 13 2 Cl C 2 5 C Red S 2 C 3 C 3 C 2 4 Ac C 2 4 Ac - The interaction between the electron accepting groups of the chromophore itself, the two anthraquinone carbonyl groups >C= and electron donating substituent groups in the (R 1,R 4,R 5,R 8 ). - Electron Donating Groups : Ar> -Alk> - 2. > - - Tertiary amines do not lead to satisfactory dye structures for they are bulky and eliminate the possibility of hydrogen bonding between adjacent amino and carbonyl groups( > - =C<). 7 Blue Br C 2 5 AC C 2 4 Ac C 2 4 Ac Color and constitution in dyes Color and constitution in dyes Anthraquinone Disperse Dyes - The more powerful the effect of the electron donor substituents, the more marked is the bathochromic shift (in the direction yellow to black) - Substitution in both the benzoid rings of anthraquinone R 1,R 4,R 5,R 8 is more effective than substitution in only one. - The appropriate substituents at the and positions can be used to augment desired properties of the dye molecule e.g. light fastness. - Progressive substitutions of the R 1,R 4,R 5,R 8 positions with and 2 groups carry the color from the orange intermediate (Quinizarin) dye=1 to the blue dye=7 with four donor groups. Dye ame R 1 R 4 R 5 R 8 1 range 2 Red Red 9 C 3 4 Red 60 2 Ar 5 Violet Blue Blue 14 C 3 C 3 Chap4-105 Chap4-106 Chap4-107 Chap4-108

ydrolysis of dye ester - The chemical group frequently found in disperse dyes is an ester group, often an acetyl group, --C-C 3 and like the acetyl groups in cellulose acetate it is susceptible to

8 ydrolysis of dye ester - The chemical group frequently found in disperse dyes is an ester group, often an acetyl group, --C-C 3 and like the acetyl groups in cellulose acetate it is susceptible to hydrolysis in neutral and alkaline conditions: - The products are acetic acid and a different azo disperse dye whose color may be quite different from that of the parent dye. - Usually the wavelength of maximum light absorption is shifted to a longer wavelength (Bathochromic shift) - The p has no fundamental role in the dyeing mechanism as such and some disperse dyes without ester groups do not need a weakly acidic dye bath. Fastness properties on polyester - If extremely high light fastness is needed (automotive fabrics) a nonionic UV inhibitor may be added to the dye bath and applied to the fiber along with the dye. - These compounds often benzotriazoles work much like sunscreen, screening out and dissipating UV radiation to prevent sunburn. - Wet fastness tests are frequently conducted after the goods have been reduction cleared and heatset at 180c for 30 seconds. - They are assessed in terms of the staining on multifiber or adjacent nylon piece goods. Rating of 4+ out of 5 are readily achieved on regular denier fibers. - Fastness to crocking or rubbing as well as dry cleaning suffers if dye migrates to the fiber surface or surface layer. Physical factors of polyester fiber Drawing : Physical factors of polyester fiber Drawing : refractive index vs dye adsorption Increase in orientation and crystallinity close packing dyeability 15min dye adsorption equilibrium dye adsorption Refractive index Refractive index Chap4-109 Chap4-110 Chap4-111 Chap4-112

9 Physical factors of polyester fiber Drawing vs diffusion coefficient Physical factors of polyester fiber eat setting Diffusion coefficient Draw ratio - Fabric set at 120 o C showed 53% exhaustion - fell to minimum values of about 34% exhaustion at heat setting temperatures between o C - rising rapidly to 75% at 230 o C. Glass transition temperature, T g Fiber structure modification - The temperature at which the moveable segments of the polymer chains become quite suddenly susceptible to deformation and displacement - The polymer properties change from glassy to rubbery and in the increasing thermal agitation of the polymer segments. - Polyester fibers are intrinsically slow dyeing at the boil. Below C they are for all practical purposes undyeable. - The temperature C which polyester dyeing begins to occur more rapidly has been called the dyeing transition temperatures. The inclusion of alternative co-monomers into regular polyester as like as follows: C C S 3 5-sulphoisopthalic acid 1,4 butane diol - The possibility of making the fiber dyeable with cationic dyes, has the effect of lowering both the melting point of the fiber and also its glass transition temperature. - The effect can be attributed to the new monomer disrupting the molecular orderliness of the structure making it easier to leave the glassy state. Chap4-113 Chap4-114 Chap4-115 Chap4-116

5 10 117 n Fiber finess - A useful preliminary relationship between the percentages of dye on weight of goods (C) needed to achieve a particular depth of shade on polyester fibers of two different

10 Cationic dyeable PET / alkali-soluble PET Poly(ethyleneterephthalate-co-5-sodiosulfoisophthalate). C Cationic dyeable Fiber structure modification C C 2 C 2 x PET m Alkali-soluble SIP, wt % C S 3 a C C 2 C 2 y Sulfonated Isophthalate (SIP) Water-dispersible / Water-soluble n Fiber finess - A useful preliminary relationship between the percentages of dye on weight of goods (C) needed to achieve a particular depth of shade on polyester fibers of two different fineness (D, denier) is given below: C C The microfiber will dye approximately three times as first which could lead to the need for procedural changes in dyeing to counter possible unevenness due to inadequate circulation. - If the same apparent depth is dyed on both fibers the wet fastness after heat setting of the shade on the microfiber will be significantly reduced. This is because of both the increased surface area and the greater percentage dye on the fiber. D D 1 2 Chap4-117 Chap4-118 Commercial products Disperse Dyes Powders Grains Pastes Reactive Dyes and Their Application Solid forms constitute two thirds of the total dye solid. Dusting can be controlled by incorporation of small amounts of oil. Grains are free from dust Pouring characteristics are very easy. ne third of disperse dye sold on paste form. With stored pastes it is important to prevent sedimentation. Chap4-119 Chap4-120

Cellulose Fibers Cotton 4 C 2 3 2 5 1 4 1 5 3 2 C 2 6-1,4-Glucoside 6 Rayon Acetate Viscose rayon Viscose rayon (DP=200~280) igh Tenacity Viscose rayon : Fortisan, Cordura, (DP=300~350) Tenasco,

11 Cellulose Fibers Cotton 4 C C 2 6-1,4-Glucoside 6 Rayon Acetate Viscose rayon Viscose rayon (DP=200~280) igh Tenacity Viscose rayon : Fortisan, Cordura, (DP=300~350) Tenasco, Durafil Polynosic : Junlon(Fujibo), Tupcel(Toyobo), (DP=400~600) Celltima(Fujibo) WM : Modal(Lenzing), Siblon( 러, Sibvolokno) (DP=350~400) Cuprammonium rayon Bemberg (German) Diacetate Triacetate Reactive groups in cellulose C 2 * C 2 n-2 C 2 It is Convenient to write as a simple representation of cellulose: Cell-. In the presence of even dilute alkalis, cellulose behaves a very weak acid and will ionize according to the normal basic dissociation equation: Cell- + - Cell K B = Cell- X - f / (b) K B known as the basic dissociation constant of cellulose. where, [Cell- - ] : the conc. f cellulosate anion [ - ] f : hydroxide ion within cellulosic fibers (a) Lyocell Tencel(Courtaulds), Lyocell(Lenzing) Chap4-121 Chap Reactive dyes In 1956 ICI introduced the first dyes for cellulosic's which would actually react with the fiber molecules, toformcovalent dye-fiber bonds. General nature of reactive dyes Three ways in which dyes can be retained by fibers Physical sorption : This relies on the same forces which attracted the dyes to the fiber initially being strong enough to hold onto the dyes through subsequent wet treatments example with direct dyeings on cellulosic fibers. Mechanical retention : This relies on the formation of insoluble pigmentary materials out of the soluble chemicals which first diffused into the fibers with vat and sulfur dyeings, those of azoic combinations, and also dyeings for mordant and ingrain dyes. Dichlorotriazine dyes Fiber Reaction: The dye molecules or ions do not lose all their Solubilizing groups after diffusion into the fibers but in the correct conditions they react and attach themselves by covalent chemical bonds to form new colored derivatives of the fibers. The small number of dye Solubilizing group is totally inadequate to cause the large new dye fiber molecules dissolve in water. Cell-- Chap4-123 Chap4-124

12 Covalent Bonds: General nature of reactive dyes - The carbon hydrogen bonds of most organic chemicals (C-). - Both atoms donate an electron to the bond and the resulting pair of electrons is shared between them. Bonds between reactive dyes and cellulose are of this type. S Dye Chap4-125 ucleophile and nucleophilic agents Polarization and reactivity : - Some of atoms share of the available electrons - e.g.itrogen,oxygen,fluorine,chlor ine and sulfur whereby they themselves tend to electronegative character and their carbon neighbors an electropositive character. - This tendency does not normally lead to ion formation. It is called Polarization. - Carbon atoms adjacent to nitrogen in the aromatic heterocyclic rings which make up many reactive groups. Such negatively charged species are called nucleophile. - ydroxide and cellulosate ions are nucleophilic reagents. δ - δ + Dye-fiber reaction Dye-fiber reaction - Cellulosic fibers contain considerable numbers of hydroxyl groups () - Reactive dyes are those whose ions or molecules contain groups which are reactive with other groups present in fibers to form covalent dyefiber bonds. - Wool contains thiols, amino and hydroxy groups S, - 2, and respectively, listed in decreasing order of reactivity - Wool reactive dyeing mechanism : ex. α-bromoacrylamide dyes For the chemist the different types of bonds involved in dyeing processes- Chap4-126 Chap4-127 Chap4-128

- They have moderate tending to poor fastness to chlorine. - Dyes and chemical costs are comparatively cheap.

13 Properties of reactive dyes Importance of reactive dyes - Reactive dyes has a full range of bright shades across the spectrum. - It shows excellent wet fastness with minimal color loss and excellent ratings for the staining of adjacent white goods, with moderate to good light fastness. - They have moderate tending to poor fastness to chlorine. - Dyes and chemical costs are comparatively cheap. - The utilization of color used to be relatively poor and the waste color going to drain can be easily 30 to 40% but this deficiency is undergoing serious recent improvements to perhaps 10%. - The end of 1961, BASF, Bayer, Ciba and Giegy, oechst, Sandoz and Sumitmo had joined ICI in the market place with no less than 12 different ranges of reactive dyes between them. 10% - The salt content of the effluent has also been very high but is rapidly falling with the use of low liquor ratios in dyeing. - In 1988 the AATCC Buyers Guide lists almost 200 different reactive dyes by color index name, representing more than 400 different commercial products. Chap4-129 Chap4-130 Reactive dye sub-groups - The differences in reactivity results for the most part from the incorporation of chemically different reactive groups in the dye molecules. Reactive dye sub-groups Chromophore Bridge Reactive group Leaving group Solubilizing agent a 3 S Cu 3 Sa S 3 a Cl Cl Chromophore Bridge Reactive group Leaving group igh reactive groups required low temperature and less amount of salt and alkali. Chromophore Reactive group Chap4-131 Chap4-132

14 General dye features Structure and performance of reactive dyes The features of Reactive dyes are- Dye Constituent Performance S C B R-X Fastness to perspiration to light Fastness to Chlorinated water Resistance to Acid ydrolysis S= Solubilizing groups C= chromogen B= Bridging groups R= Reactive groups X= leaving groups Chromophore Bridge Resistance to Alkali ydrolysis Washing Fastness Dyeing Property at low temp. Reactive group Washing off Property Dye-X + u- Dye-u + X- Solubility Chap4-133 Exhaustion and Fixation Chap4- Reactive Dye- Monofunctional Reactive Dye- Monofunctional 40 C 40 C 80 C 60 C Dichloroquinoxaline : Levavix E (Bayer) Aminochlorotriazine : Procion (Zeneca) Vinylsulphone(Sulphatoethylsulphone) : Remazol (E) Sumifix (K) 80 C 40 C 40 C Trichloropyrimidine : Drimarene X (Sandoz) Chlorodifluoropyrimidine : Drimarene K (Sandoz) Aminofluorotriazine : Cibacron F (Ciba) Chap4-135 Chap4-136

Reactive Dye- Bifunctional Classification of Reactive Dyes Bis-Amoniochlorotriazine : Procion -E (Zeneca) Bis-icotinotriazine : Kayacelon React (KYK) Aminochlorotriazine-vinylsulphone : Sumifix supra

15 Reactive Dye- Bifunctional Classification of Reactive Dyes Bis-Amoniochlorotriazine : Procion -E (Zeneca) Bis-icotinotriazine : Kayacelon React (KYK) Aminochlorotriazine-vinylsulphone : Sumifix supra (SK) Aminoflulorotriazine-vinylsulphone : Cibacron C (Ciba) Chap4-137 Chap4-138 Reactive Dye 의역사 - 구조 / 반응온도 / 용도 ydrolysis of reactive dyes - Dye molecules can be hydrolyzed in aqeous dyebath which contain water - 2 is a nucleophile which can attack the reactive groups Dye C Cl C C Cl C + - Dye C C Dye ydrolyzed in the bath Fiber Dye ydrolyzed inside the fiber Dyebath Chap4-139 Chap4-140

Disperse dyes. Disperse Dyes and Their Application to Polyester. Fundamental behavior of dyes. Fundamental behavior of dyes

Disperse dyes. Disperse Dyes and Their Application to Polyester. Fundamental behavior of dyes. Fundamental behavior of dyes Fundamental behavior of dyes Fundamental behavior of dyes - The specific reactions concerned depend on the chemical character of the fiber, and therefore choice of dye is restricted to those capable of