Textile Chemistry, Textile auxiliaries, สารช่วยทางสิ่งทอ

สารชว่ยทางสิ�งทอ (TEXTILE AUXILIARIES)Wirote Sarakarnkosol

Outlines

� ความหมายและการแบง่ประเภทของสารชว่ยทางสิ�งทอ

� ความรูว้ทิยาศาสตรพ์ื9นฐานเกี�ยวกบัสารลดแรงตงึผวิ (surfactant) (surfactant)

� สารชว่ยทางดา้นสิ�งทอที�ไมใ่ชส่ารลดแรงตงึผวิ (non-surfactant)

� หนา้ที�ของสารชว่ยสิ�งทอประเภทตา่งๆ� การเลอืกใชส้ารชว่ยทางดา้นสิ�งทอเพื�อความ

เหมาะสมกบัสยีอ้มแตล่ะชนดิ

ความหมายของสารชว่ยทางสิ�งทอ

� เป็นสารที�ใชใ้นกระบวนการสิ�งทอที�นอกเหนอืไปจากสียอ้มและวสัดุ

� ชว่ยทําใหก้ระบวนการทางสิ�งทอนั9นมคีวามแมน่ยําและควบคมุเพื�อใหไ้ดผ้ลตามที�ตอ้งการไดด้ขี ึ9น เชน่� เพื�อทําใหว้สัดพุรอ้มที�ทําการยอ้ม-พมิพไ์ด ้เชน่ สารในกลุม่ � เพื�อทําใหว้สัดพุรอ้มที�ทําการยอ้ม-พมิพไ์ด ้เชน่ สารในกลุม่

Scouring, Bleaching, Desizing� เพื�อควบคมุการดดูซมึสยีอ้ม เชน่ Levelling agent,

Retarder � เพื�อทําใหก้ารคงสภาพของสใีนนํ9ายอ้มหรอืแป้งพมิพด์ขี ึ9น

เชน่ Defoamer, Thickener, Dispersing agent� เพื�อเพิ�มความคงทนของสยีอ้มไดด้ขี ึ9น เชน่ Fixing agent,

Reduction clearing

การแบง่ประเภทของสารชว่ยทางสิ�งทอ

� โดยทั�วไปจะแบง่ออกเป็น 2 ประเภทใหญ ่� Surfactants หรอื สารลดแรงตงึผวิ ที�มคีวามสามารถใน

การลดแรงตงึผวิ และมโีครงสรา้งทางเคมทีี�ม ี2 สว่น คอื Hydrophilic และ Hydrophobic ทําใหส้ามารถอยูใ่นสว่น interface ได ้สว่น interface ได ้

� Non-surfactants หรอื สารที�ไมส่ามารถลดแรงตงึผวิได ้สว่นใหญจ่ะเป็นสารละลายนํ9าได ้เนื�องจากกระบวนการสิ�งทอเป็นกระบวนการที�ใชนํ้9าเป็นตวักลาง แตใ่นบางกรณีก็เป็นสารที�ไมล่ะลายนํ9า ก็จะมกีารใชส้ารในกลุม่ surfactant มาชว่ยทําใหก้ระจายตวัในนํ9าได ้

ตวัอยา่งของสารชว่ยประเภท Surfactant

� Detergent and scouring agent� Wetting agent/Rewetting agent� Dispersing agent� Levelling agent (AE, Leveling agent)� Levelling agent (AE, Leveling agent)� Retarder� Emulsifier� Solubiliser (AE, Solubilizer)� Foaming and defoaming agent

ตวัอยา่งของสารชว่ยประเภท Non-surfactant� Electrolyte and pH control agent� Enzyme� Reducing and oxidising agent/ Reduction inhibitor� Sequestering agent/Chelating agent� Hydrotropic agent� Thickener/Migration inhibitor� Dyeing accelerator /Carrier� Fixing agent� Optical brightening agent (OBA)

ความหมายของ Surfactant

Surfactant = Surface active agent= Interface active agent = Tenside (นยิมใชใ้นสหภาพยโุรป)

InterfaceSurface

โครงสรา้งพื9นฐานของ Surfactant

HeadTail

Hydrophile (Polar)Hydrophile (Polar)Hydrophilic groupHydrophilic groupLipophobic groupLipophobic group

Hydrophobe (NonHydrophobe (Non--polar)polar)Hydrophobic groupHydrophobic groupLipophilic groupLipophilic group

Influence of chemical structure of surfactants

Hydrophile

Type Charge Examples

Anionic Carboxylate (RCOO-M+), Sulphonate (RSO3

-M+), Sulphate (ROSO -M+),

--

เป็นสว่นที�ชอบนํ9า และไมช่อบนํ9ามนั เนื�องจากความมขีั 9ว/ประจ ุเชน่

Sulphate (ROSO3-M+),

Phosphate (ROPO3-M+)

Cationic Quaternary ammonium halides ( R4N+Cl-)

Amphoteric(Zwitter ion)

Sulfobetaines (RN+(CH3)2CH2CH2SO3

- )

Nonionic Polyoxyethylene(-CH2CH2O-)nPolyol group

++

--++

Hydrophobe

เป็นสว่นที�ไมช่อบนํ9า และชอบนํ9ามนั เนื�องจากความไมม่ขีั 9ว/ประจเุชน่

� Long, straight-chain alkyl group ( C8 –C20 with terminal substitution of the head group).

� Branched-chain alkyl groups ( C8-C20 , internal substitution).Alkylbenzenes ( C -C C H with various substitution patterns)� Alkylbenzenes ( C8-C15C6H4 with various substitution patterns)

� Alkylnaphthalenes (alkyl usually C3 or greater).� Fluoroalkyl group ( partially or completely fluorinated)� Polydimethylsiloxanes (-OSi(CH3)2O-)� High molecular weight polyoxypropylene glycol derivatives.� Rosin derivatives.� Misellaneous structures

การเปรยีบเทยีบ Hydrophile ชนดิตา่งๆ

CH3(CH2)10CH2OH

OH

CH3(CH2)10CH2OSO3H

CH3(CH2)10CH2O(CH2CH2O)nH

CH3(CH2)10COOHn-dodecylalcohol( laurylalcohol )

dodecane sulphoric acid ester

dodecyl polyoxyethylene

โดยการใช ้Hydrophobe ชนดิเดยีวกนั

CH3(CH2)10CH3

OHCH3(CH2)8CHCH2CH3

CH3(CH2)10CH2SO3H

CH3(CH2)10CH2Cl

CH3(CH2)10CH2N+(CH3)3Cl-

CH3(CH2)10CH2N+(CH3)2(CH2)3SO3-

dodecane

3-dodecanol

dodecane sulphonic acid

dodecanoic acid

lauryltrimethylammoniumchoride

N-dodecyl-N-N-dimethyl-3amino propane-1-sulphonic acid

แรงตงึผวิ (Surface tension)

� แรงยดึเหนี�ยวของสารที�อยูท่ี� Surface นั9น จะนอ้ยกวา่สารที�อยูใ่น Bulk � ทําใหก้ารเคลื�อนตวัมาสูท่ี� Surface นั9น ตอ้งใชพ้ลงังาน (dG) Surface นั9น ตอ้งใชพ้ลงังาน (dG) ในการทําลายแรงยดึเหนี�ยว � และพบวา่คา่ dG นั9นเป็นอตัราสว่นกบัคา่พื9นที�ผวิที�เกดิมากขึ9น (dA) โดยที�อตัราสว่นของ dG/dA นั9นเป็นคา่คงที�เสมอ (ที� T คงที�) ซึ�งคา่คงที�นั 9นเราจะเรยีกวา่ Surface tension (γ) ที�มหีน่วยเป็นแรง/ความยาว (force/length)

คา่ Surface tension (γ) ของของเหลวบางชนดิที� 20°C

ความแตกตา่งสารแตล่ะประเภทตอ่คา่ Surface tension เมื�อละลายนํ9า

เป็นสารกลุม่เกลอือนนิทรยี ์เชน่ NaCl หรอืสารอนิทรยีท์ี�มขีั 9วสงู เชน่ Glucose

เป็นสารกลุม่ตวัทําละลายอนิทรยีทั์�วไป

เป็นสารกลุม่ Surfactant เป็นสารกลุม่ Surfactant

Percent Concentration required to reduce the surface tension of water to indicated values

Surface tension, dynes per cm

73 50 40 30 22

Softanol 90 0 0.0003 0.0008 0.0050 -

Ethanol 0 9 18 40 100

คา่ Surface tension ที�มผีลตอ่ Wettability

ขอ้ควรจํา : ถา้ของเหลวใดๆม ีSurface tension ตํ�ากวา่ ผวิของวสัดนัุ9นๆ ของเหลวนั9นจะสามารถเปียก (Wettability) บนผวิวสัดไุด ้

แตใ่นทางตรงกนัขา้ม ถา้คา่ Surface tension ของของเหลวสงูกวา่วสัด ุของเหลวนั9นจะไมส่ามารถเปียกหรอืแทรกเขา้สูว่สัดนัุ9นได ้

การเกดิ Micelles ชนดิตา่งๆของ Surfactant

4 nm

Normal micelles

Spherical Cylindrical Bilayer lamella

Unimers (monomers)

Reverse micellesInverted hexagonal phase

Aggregates

CMC : Critical micelles concentration

Conductivity

Phys

ical

pro

pert

y

Surface tension

Turbidity

Osmotic pressure

CMC Surfactant concentration

Phys

ical

pro

pert

y

ความสมัพันธร์ะหวา่งความเขม้ขน้และพฤตกิรรมของ surfactant

Air

Water

(a) Extremely dilute solution

(b) Dilute solution (c) Solution at CMC (d) Solution withconcentrationabove CMC

Small micelle

Spherical micelle

พื9นฐานกลไกการละลายนํ9า

การละลายของ Ionic surfactant

-- ++

อณุหภมูสิงูขึ9น

-- ++

++ -- ++ --

เมื�ออณุหภมูสิงูขึ9น พลังงานในการทําลายพันธะก็จะสงูขึ9น ทําใหเ้กดิการแตกตัวระหวา่งประจตุรงกนัขา้มมากขึ9น สง่ผลทําใหก้ารละลายดขีึ9น

Krafft temperature (TK)

� บางทเีรยีกวา่ Krafft point เกดิขึ9นกบั ionic surfactant เทา่นั9น

� ที�อณุหภมูสิงูกวา่ TK สาร ionic surfactant จะละลายได ้อยา่งรวดเร็ว และกอ่ใหเ้กดิ micelles ได ้สว่นที�ตํ�ากวา่จะอยูใ่นรปูผลกึ ไมส่ามารถเกดิเป็น micelles ได ้จะอยูใ่นรปูผลกึ ไมส่ามารถเกดิเป็น micelles ได ้

Sodium laurate (C12)

Sodium myristate (C14)

Sodium palmitate (C16)

Sodium stearate (C18)

Temperature (°°°°C)

So

lub

ility

(%)

Hydrophilic -Lipophilic Balance (HLB value)

HLB rangeHLB range Behavior in waterBehavior in water

1-4 No dispersibility

3-6 Poor dispersion

HydrophileHydrophileHydrophobeHydrophobe

3-6 Poor dispersion

6-8 Unstable milky dispersion

8-10 Stable milky dispersion

10-13 Translucent

> 13 Clear solution

Application of various HLBs of surfactants.

HLB rangeHLB range ApplicationApplication0-4 Defoaming

3-6 w/o Emulsifier

Hydrophobic

3-6 w/o Emulsifier

7-9 Wetting agent

8-18 o/w Emulsifier

13-15 Detergent

15-18 Solubiliser / Disperser Hydrophilic

HLB : Hydrophilicity

Anionic surfactantAnionic surfactant

-OSO3Na-SO3Na

-OPO3Na2-COONa

-OH-O-> >>

=

-SO3Na=N+Cl-

-COONa -O-> >>

>

R(-CH2CH2O-)9H R(-CH2CH2O-)3H

Nonionic surfactantNonionic surfactant

Main types of surfactants by ionic nature

--

++( Anionic surfactant )

( Cationic surfactant )

Ionic surfactant

++

--

--++

( Cationic surfactant )

( Amphoteric surfactant )

(nonionic surfactant )

Classification by whether surfactant ionizes or not

Classification by type of ion resulting from ionization

SurfactantSurfactant

Classification of various types of hydrophilic groups

Anionic surfactant

Cationic

R -COONa R -OSO3Na

R -SO3Na R -OPO3Na

R -NH2.HCl R

CH3-N.HClH

CH

( Carboxylate type) ( Sulphate type)

( Sulphonate type) ( Phosphate type)

( Primary amine salt) ( Secondary amine salt) Cationic

surfactant

Amphoteric surfactant

Nonionicsurfactant

Classification by ionic type

Classification by type of hydrophilic group

SurfactantSurfactant

RCH3-N.HClCH3

RCH3-N+-CH3

.Cl-CH3

R -NHCH2CH2COOH

RCH3-N+-CH2COO-

CH3

R -O-(CH2CH2O)nH

RCH2OH

-COOCH2C-CH2OHCH2OH

( Polyhydroxy alcohol type)

( Polyethyleneglycol type)

( Betaine type )

( Amino acid type)

( Secondary amine salt)

( Quaternary ammonium salt) ( Tertiary amine salt)

Anionic surfactant

Effect of counter ion of anionic surfactants

Properties of anionic surfactant

Cationic surfactant

Various substitution of cationic surfactant

Properties of cationic surfactant

Non-ionic surfactant

Cloud point ของ Nonionic surfactant

Colourless and transparent

Cloudy like milk

TransparentAs originally

Heating aboveCloud point

Cooling

Aq. Soln of nonionic surfactant

(Cold)

Aq. Soln of nonionic surfactant

(Hot)

Nonionic surfactant separated out as oil droplets

Phase separated

Nonionic surfactant

Water

การละลายของ Nonionic surfactant

Cloud point mechanism

Soluble at low Temp. Clear

Insoluble at high Temp.

Higher tempLower temp

Milky

Cloudy

Cloud point

Cloud point of NP-X EO

ไมส่ามารถละลายนํ9าได ้จงึจําเป็นตอ้งเตมิตัวทําละลายอนิทรยี ์เพื�อที�จะทําใหว้ดัคา่ได ้

สามารถละลายนํ9าได ้และคา่ cloud point ตํ�ากวา่จดุเดอืดcloud point ตํ�ากวา่จดุเดอืดของนํ9าจงึสามารถวัดไดโ้ดยตรง

คา่ cloud point สงูกวา่จดุเดอืดของนํ9าจงึ ไมส่ามารถวดัไดโ้ดยตรง ตอ้งเตมิสารelectrolyte เพื�อทําใหว้ดัคา่ได ้

ดงัน ั4น การรายงานคา่ cloud point จงึตอ้งระบสุภาวะวา่1. 1% ในสารละลายผสม เชน่ water-butyldiglycol (75:25), water-n-propanol

(50:50), water-dioxane (57:43) ถา้ Cloud point ตํUากวา่ 20 °C2. 1% ในนํ 4าบรสิทุธิZ ถา้ Cloud point อยูใ่นชว่ง 20-90°C3. 1% ในสารละลาย NaCl 10% aq.ถา้ Cloud point สงูกวา่ 90°C

HLB calculation for non-ionic surfactants

Properties of ethoxylated nonionic surfactants

Ethylene oxide-Propylene oxide non-ionic surfactants

Properties of EO-PO nonionic surfactants

Amphoteric surfactant

ผลของ pH ตอ่ประจขุอง Amphotericsurfactant

+H

--++ H+H+

--++

OH-

H

--++OH-OH-

General properties of amphotericsurfactant

Emulsification / detergency / wetting

Wetting agent and rewetting agent

Wettability : ความสามารถในการเปียก

Contact angles at the fibre surface for wetting and non-wetting

Wetting agent : ลกัษณะทางโมเลกลุ 1

� สารที�มหีมู ่hydrophilic ที�อยูต่รงกลางจะให ้wetting power ที�สงูกวา่ที�อยูป่ลาย

สงู wetting power ตํ�า

� สารที�มหีมู ่hydrophobic ที�เป็นโซก่ิ�งหรอืม ีAromatic ก็จะให ้wetting power ที�เป็นโซต่รง

หรอืสงู wetting power ตํ�า

Wetting agent : ลกัษณะทางโมเลกลุ 2

� ในกรณีที�เป็น non-ionic surfactant จะตอ้งมจํีานวนหมู ่Ethylene oxide พอเหมาะ (มคีา่ HLB 7-9)

Low solubility : Lower wetting power

EO EO EOEOEO

EO EO EOEOEO EO EO EOEOEO

EO EO EO Low solubility : Lower wetting power

High water affinity :Lower wetting power

Optimum EO : Highest wetting power

pH of wetting agent application

pH Anionic wetting agent Nonionic wetting agent

Strongly alkaline

Easily soluble surfactants with relatively low MW are applicable. Those with ester linkage are hydrolyse

Not-applicable (insoluble)

Weakly alkaline Applicable Generally applicable

Nearly neutral Applicable Applicable

Weakly acidApplicable, Sulphate type surfactant are decomposed dependinf on conditions.

Applicable

Strongly acidGenerally not applicable. In some cases particular sulphonate type are applicable

Generally applicable

pH of textile application

Mercerization, Causticization

General scouring, bleaching, Dyeing (Vat, Sulphur)

Strongly alkaline

Weakly alkaline (Vat, Sulphur)

Desizing, Dyeing (Direct, Reactive)

Strongly acid

Weakly alkaline

Nearly neutral

Weakly acid Chlorite bleaching, Dyeing (Acid, Disperse)

Carbonization

Wetting agent for desizing process

� Enzymatic desizing� Not deactivate enzyme� Good detergency� Should use nonionic wetting agent

Polyethylene glycol ether� Polyethylene glycol ether� Block copolymer EO, PPO ether

� Oxidative desizing : should use nonionic or sulphonate anionic type� Resistance to persulphate

� As Enzymatic desizing� Sulphosuccinate derivative

Wetting agent for scouring process

� High wetting power� Good detergency and emulsifying� Not specify the chemical alone� Should use the blends of anionic and nonionic � Should use the blends of anionic and nonionic

surfactant.� Fatty alkyl sulfate, sulfonate and phosphate� Ethoxylated fatty alcohol� Ethoxylated octyl-/ nonylphenol

Wetting agent for bleaching

� Resistance to oxidising agent� H2O2 resistance

� Ethoxylated alkyl phenol

� Hypochlorite resistanceHypochlorite resistance� Disodium alkyl diphenyl ether� Sodium alkane sulfonate

� Chlorite resistance� EO of short chain carbon alcohol� EO of alkylphenol� EO + anionic surfactant

Wetting agent for carbonising process

� Resistance the mineral acid condition� Nonionic surfactant� Sulfonated anionic surfactant

Wetting agent for mercerisation

� Resistance to strongly alkaline� Small hydrophobic group and good alkaline

solubility� Phenol derivative� Blends of ethyl hexanol sulfate with organic solvent� Short-chain alkylphosphonate esters

Conventional wetting agent(insoluble in concentrated alkaline)

Wetting agent for mercerisation

� soluble in concentrated alkaline

� poor wetting in neutral

� still wetting property in alkaline

Rewetting agent

� Promote wetting property of substrate after drying

� Not necessary to good wetting property� Anionic surfactant� Anionic surfactant� High EO unit nonionic surfactant

Scouring agent / Detergent

Scouring agent / Detergent

� Factor for scouring

Effects of scouring agent

Wetting/Penetrating effect Emulsifying/dispersingSolubilizing effect Detergency

Scouring

agent

Mechanical effect involved in washing

Detergency Foaming effect Other effects

Scouring agent : ลกัษณะทางโมเลกลุ

� Longer chain hydrophobic with remaining soluble

� Linear hydrophobic part� End position of hydrophilic part� Cloud point is slightly higher than process � Cloud point is slightly higher than process

temperature (non-ionic)� Optimum EO unit (different for hydrophobic

part)� Ionic head group can increase the detergency of

PEO surfactant (e.g. Laureth sulfate)� Not adsorb on the fiber

Detergency

คา่ % Detergency ของ Surfactant แตล่ะชนดิ

Detergent % Detergency

Sodium salts of sulfuric ester of higher alcohol 35.3Lauryl diethanolamide (1:2 type) 48.4Blends of above detergent 46.010 mole EO adducts of nonylphenol 47.010 mole EO adducts of nonylphenol 47.0� 0.3% solution of each chemical� % Detergency = [(A – B)/(C – B)] x 100

Where A = Reflectant of soiled fabric after washB = Reflectant of soiled fabric before washC = Reflectant of white fabric

• Standard soiled solution contained1 part Fully hydrogenated tallow3 parts Liquid paraffin0.8 part Carbon black800 parts Carbon tetrachloride

Emulsifier & Dispersing agent

� Emulsifying agent (Emulsifier)� Agent for help immiscibility

liquid/liquid to uniformly distribute in each phase distribute in each phase (liquid/liquid)

� Dispersing agent� Agent for help uniformly

distribute of solid in liquid phase (solid/liquid)

Emulsification and Dispersion stability

Emulsifier

� High HLB values use for O/W emulsion

� Low HLB values use for W/O emulsionMix of 2 or 3 emulsifiers� Mix of 2 or 3 emulsifierscan gave emulsion stability than those of single use� All of type of surfactant

can be used for emulsifier depends on liquid/liquid phase

Different of anionic and nonionic emulsion (o/w emulsion)

Emulsion type : drop size

Dispersing agent

� Dispersing agent for disperse dyes� Anionic dispersing agent

� Naphthalene sulfonate� Lignin sulfonate

� Nonionic dispersing agent� Higher EO alcohol ethoxylate� Higher EO non-ionic surfactant

Typical anionic dispersing agent

Napthalene sulfonate

Lignin sulfonate

Model of the disperse dye system

Dispersion thermal stability on dispersing agent structure

Levelling agent

Levelness

Unlevelness

Unlevelness

Level dyeing problems can be divided into two broad categories:1 ) Gross unlevelnesGross unlevelnesss::

- Unlevelness is primarily related to the dyeing equipment or processequipment or process

- Substrate is often uniform in both chemically and physically properties.

2) Localised unlevelnesLocalised unlevelnesss::- Related to physical and/or chemical nonuniformity of substrate

- Examples: Barriness/Nylon or polyesterSkitteriness/Wool

Level dyeing

There are also two fundamental mechanisms that can contribute to a level dyeing:

1) Control of rate of exhaustion of dye so that it is takenup evenlyup evenly

2) Migration of dye after initially unlevel sorption on the fiber.

Either or both of these mechanisms may operate to a greater or lesser extent in a given dye–fiber system

Main mechanisms of levellingagents

� Nonionic agents � Usually form water-soluble complexes with the dye,

some degree of solubilisation being involved

� Ionic agents � Dye-substantive

� Form complexes with the dye and there is competition between the levelling agent and the fibre for the dye

� Fibre-substantive� competition between levelling agent and the dye for the fibre

Levelling agent types and their uses

Levelling agent for acid dyes

� Anionic levelling agent

� Cationic levelling agent

Levelling action mechanism for acid dyes on nylon

Levelling action mechanism for acid dyes on nylon

Schematic representation of solubilised acid dye-agent complex

Levelling agent for disperse dyes

� Non-ionic levelling agent tend to be separated at high temperature but can increase dyes solubilisation (Low cloud point)

� Anionic levelling agent can increase the cloud point of nonionic agentnonionic agent

� Should synergistic mixing together� 7-10% of B in A can increase cloud point of A alone

(105oC) to 150oC� Fully effective at pH >7 (Carefully selection of dyes)

(A) fatty acid ethoxylate (B) sodiumdodecylbenzenesulphonate

Levelling agent for disperse dye

� Modified nonionic (or Modified anionic, Weakly anionic)� Phosphate ester ethoxylation

� High temperature stability� Protect hardness and trace metal ion� Stabilise under high concentration of electrolyte� Fully effective at pH 4-5 (pH of disperse dyeing)

Levelling agent for disperse dye

� Oligo-soaps or Ethoxylated multi-ester compounds.

� More stable dye dispersion at high temperatureSolubilisation take place at a lower temperature� Solubilisation take place at a lower temperature

� Dyeing rate at lower temp. is much slower� Solubilisation of oligomer and acrylic size� Low foaming

Defoaming agent

Foam breaking mechanism

� Commonly used agents are insoluble oils, polydimethylsiloxanes and other silicones, certain alcohols, stearates and glycols.

� Used to prevent formation of foam or is added � Used to prevent formation of foam or is added to break a foam already formed.

Typical defoaming agent

� Oil based defoamers� Relatively poor foam control� Some tend to leave deposit on machine� Example is propylene-1,2-glycol mononeodecanoate� Example is propylene-1,2-glycol mononeodecanoate


� Silicone based defoamers� High efficiency for controlling the foam� If the emulsion use not suitable emulsifier,

Silicone spot is usually occur.Silicone spot is usually occur.� Example is ethoxylated polydimethyl siloxane


� EO/PO based defoamers� Contain polyethylene glycol and polypropylene

glycol copolymers. � Have good dispersing properties Have good dispersing properties � Often well suited when deposit problems are an

issue.

Non-surfactant auxiliaries

� Electrolyte� pH control� Enzyme� Reducing and Oxidising agents� Reducing and Oxidising agents� Sequestering agent � Thickener and Migration inhibitor� Hydrotropic agents� Fastness improving agents� Optical brightening agents

Electrolyte

Electrolyte

� NaCl and Na2SO4 are commonly used. � Increase the adsorption of Reactive and Direct

dyes on cellulose. (Also for leuco Vat and Sulphur dyes)Sulphur dyes)

� Promote aggregation of soluble dyes.� NaCl gave stronger effect than Na2SO4.

Electrolyte effect on cellulosic dyeing system

� Equilibrium adsorption isotherm at 34oC and rate of dyeing at 40oC for CI Direct Blue 1 on viscose in the presence of electrolyte singly and binary mixture

Electrolyte effect on cellulosic dyeing system� Fixation of CI Reactive Red 180 with various concentrations of Group IA chlorides

Electrolyte effect on cellulosic dyeing system� Fixation of CI Reactive Red 180 with various concentrations of potassium salts of

dicarboxylic acids

K oxalate

K tartrate

K phthalate

Electrolyte on ionic dyeing system

� Decrease the adsorption of Anionic dyes on PA and WO.

Kosmotropes increase hydrophobic � increase dye adsorptionChaotropes decrease hydrophobic � decrease dye adsorption

NaCl gave more decreasing the adsorption of anionic dyes on PA than Na2SO4 !!

Electrolyte : Ecological approach

� High salt loading is indesirable in waste-water.� Na2SO4 causes corrosion of concrete pipes.

pH control

pH control : 3 different techniques

1. Maintenance of a high degree of acidity or alkalinity

2. Control pH within fairly narrow tolerance mainly in the near-neutral region (pH 4-9)mainly in the near-neutral region (pH 4-9)

3. Gradual shifting of the pH as dyeing proceeds

pH control: Maintenance of a high degree of acidity or alkalinity

� Easy to control � Acidic region use in application of levelling acid

and 1:1 metal complex dyes to PA and WO. � Alkaline region use in reactive, sulphur or vat� Alkaline region use in reactive, sulphur or vat

dyes to CEL.

pH control:pH value of some common acid in distilled water

Normality2 N 1 N 0.1 N x N 0.01 N 0.001 N

Material

Hydrochloric acid g/l - 36.5 3.65 1 g/l 0.37 0.037

HCl pH - 0.11 1.08 1.61 2.00 3.00

Sulphuric acid g/l - 49.0 4.9 1 g/l 0.49 0.049Sulphuric acid g/l - 49.0 4.9 1 g/l 0.49 0.049

H2SO4 pH - 0.24 1.17 1.79 2.05 3.00

Formic acid g/l 92.0 46.0 4.60 1 g/l 0.46 0.046

HCOOH pH 1.61 1.79 2.32 2.76 2.85 3.42

Lactic acid g/l 180.0 90.0 9.00 1 g/l 0.90 0.090

C3H6O3 pH 1.78 1.97 2.43 2.94 2.95 3.50

Acetic acid g/l 120.0 60.0 6.00 1 g/l 0.60 0.060

CH3COOH pH 2.18 2.40 2.87 3.27 3.37 3.89

pH control:pH value of some common base in distilled water

Normality2 N 1 N 0.1 N x N 0.01 N 0.001 N

Material

T.S.P.P. g/l - 83.0 8.30 1 g/l 0.83 0.083

Na4P4O7 pH - 10.50 10.15 9.35 9.25 9.01

Sodium carbonate g/l 106.0 53.0 5.30 1 g/l 0.53 0.053

Na CO pH 11.60 11.50 11.00 10.30 10.00 9.80Na2CO3 pH 11.60 11.50 11.00 10.30 10.00 9.80

Ammonia g/l 34.0 17.0 1.70 1 g/l 0.17 0.017

NH4OH pH 11.72 11.59 11.16 11.00 10.64 10.15

Sodium phosphate g/l 98.6 49.3 4.93 1 g/l 0.49 0.049

Na3PO4 pH 12.8 12.30 11.40 11.20 11.10 10.95

Sodium hydroxide g/l - 40.0 4.00 1 g/l 0.40 0.040

NaOH pH - 13.93 12.98 12.38 12.00 11.00

pH control : Near-neutral region (pH 4-9)

� Very difficult to control.� pH of pure water 7.47 at 0oC, 7.00 at 24oC and

6.13 at 100oC.� Use in Milling acid and 1:2 metal complex dyes� Use in Milling acid and 1:2 metal complex dyes

on PA and WO., Basic dyes on PAN and Disperse dyes on PES, PA, PAN.

� Precise control with buffer.

Buffer

� Buffers are generally based on combinations of weak acid + its base salt or weak base + its acid salt

� Most common buffer is acetic acid/sodium � Most common buffer is acetic acid/sodium acetate (pH range 3.8 – 5.8)� Low cost� Tend to volatile

Titration curve of acetate buffer

Buffer : Phosphate buffer

� Higher cost than acetate buffer� More resistant to temperature induced change� Buffering region at pH 2.5-3.5, pH 6-8 and pH 10.5-11

Titration curve of Phosphate buffer

Buffer : Others

� Pyrophosphoric acid (H4P2O7) and its salts (pH 3–9)

� Orthoboric acid (H3BO3), sodium tetraborate(borax Na2B4O7) and sodium hydroxide (borax Na2B4O7) and sodium hydroxide (pH 8.1–10.1)

� Citric acid and sodium hydroxide (pH 2.1–6.4)

� Sodium carbonate and sodium bicarbonate (pH 9.3–11.3).

pH control : Shifting of the pH

� Acid shift region use for non-migrating anionic dyes on WO or PA.

� Ammonium salts is the conventional system for acid shifting.system for acid shifting.

� Alkali shift region use for reactive dyes on CEL.

� Sodium salts of volatile acid is the conventional system for alkaline shifting.

ผลของ pH shifting agent ชนดิตา่งๆ

Acid shifting : Ammonium salts

� Ammonium sulfate generally used for dyeing milling acid dyes on PA and WO.

� Can be used only open system.

Acid liberate

Volatile to atmosphere

Acid shifting : Hydrolysable ester

Acid part

Alcohol part

Diethyl tatrate 2-Hydroxyethyl chloroacetate

Acid part

Alcohol part

Alcohol part

Acid shifting : Lactone

γγγγ-butyrolactone

Alkaline shifting : Salt of weak acid

Sodium acetate

Alkali liberate

Sodium formate and Sodium bicarbonate are also used for reactive dyes on CEL printing.

Enzyme

Enzyme : Definition

� Biocatalyst for accelerating the reaction� α-amylase use for desizing process� Catalase for removing residual H2O2 after � Catalase for removing residual H2O2 after

bleaching� Cellulase for biofinishing of denim� Etc.

Amylase enzyme for desizing

� Convert starch to water-soluble product� Non-ionic wetting agent should be combine

used� Temperature range cover 20 – 115oC

:Prefer > 70oC (gelatinous point of starch):Prefer > 70oC (gelatinous point of starch)� pH range cover 5.5 – 9 : Prefer pH 7 – 8

(condition for degraded product solubilisation)

� Salt and Hardness maybe require. � Detect residual starch with Iodine solution

Cotton warp yarn and its impurities

Mechanism for enzymatic desizing

Mode of action of enzymatic degradation : by SDC

Various types of amylase for desizing

Optimum conditions for enzymatic desizing : by SDC

Checking for desizing

Test for degree of desizing (TEGEWA scale) : by SDC

Complex of starch with iodine

Catalase

� Remove residual H2O2 to water and oxygen.� Activity range pH about 5-9� Activity range temperature 50-55oC� Do not destroy the dye molecules.� Do not destroy the dye molecules.

Cellulase :Dissolution of the cellulose

Cellulase : Denim finishing

� Denim is cotton twill-weave fabric with a dyed warp with INDIGO and raw white weft.

� Acid cellulases (pH 4.5–5.5 ; 45–55oC) give high aggressive action on cotton which use shorter time but backstaining.aggressive action on cotton which use shorter time but backstaining.

� Neutral cellulases (pH 6–8 ; 50–60oC)have less aggressive action but less or no backstaining.

� Terminated with inactivating, by raising the pH to 10 or by increasing the temperature to75oCfor 10–15 minutes.

Cellulase : Application

Reducing agent & Oxidising agent

Typical application of Reducing agent & Oxidising agent

Coloration assistance- Reducing agent for Vat & Sulphur dyes- Re-oxidising agent for Vat & Sulphur dyes

Decoloration of material- Bleaching- Stripping

Redox inhibitor- Reduction inhibitor- Antioxidant

3 ACTIONS

Reduction of Vat dyes

Reducing agent : Vat dyes assistant

Reduction potentials of various reducing agents measured as 5 g/l solutions in 15 ml/l caustic soda 38oBé at 60oC

Vat dyes have reduction potentials in aqueous media from –770 to –1000 mVthe majority –900 to –950 mV.

Reduction of Sulphur dyes

Sulphur dyesSulphur dyes

Reducing agent : Sulphur dyes assistant

Reduction potentials of various reducing agents measured as 5 g/l solutions in 15 ml/l caustic soda 38oBé at 50oC

Sulphur dyes have average only about –600 mV

Reduction clearing of Disperse azodyes

Reducing agent :

Fastness of black polyester dyeings after various reduction clearing treatments

Reducing agent : Sodium dithionite/Hydros/Sodium hydrosulfite

� Most important reducing system for the batchwise application of vat dyes in a solution of sodium hydroxide.

� For sulphur dyes, the process is difficult to � For sulphur dyes, the process is difficult to control and may be destroyed through “OVER-REDUCTION”.

� But effective with CI Solubilised Sulphurand sulphurised vat dyes.

� Reduction clearing for Disperse dyes.

Reducing agent : Sodium dithionite/Hydros/Sodium hydrosulfite

Reduction reaction of hydros with Vat dyes

Reduction reaction of hydros with atmosphere

Reducing agent : Sodium dithioniteEnvironmental problems

� Can produce sulphite and sulphate.� Sulphite can be oxidised easily to sulphate� High concentrations of sulphate can cause

damage to unprotected concrete pipes.damage to unprotected concrete pipes.

Sodium dithionite : Summary

Advantages(1) Sufficient reduction potential for vat, sulphur or indigo

dyeing(2) Good stability of leuco vat dyebaths(2) Good stability of leuco vat dyebaths

Disadvantages(1) Waste water loading; inhibits biological degradation and

leads to a greater oxygen demand(2) Can cause over-reduction at higher temperatures(3) Special safe storage facility required

Reducing agent : Sodium sulfide and Sodium hydrogen sulfide

� Most widely used for Sulphur dyes� At least 12 g/l sodium sulfide is required to

dissolve the water-insoluble CI Sulphur dyes� Sodium hydrogen sulfide is use 0.6 times of � Sodium hydrogen sulfide is use 0.6 times of

sodium sulfide but necessary to add alkali (10 g sodium hydroxide or 5 g sodium carbonate per 7 g sodium hydrogen sulfide)

Reducing agent : SulfideEnvironmental problems.� Toxicity of hydrogen sulphide.� Odour threshold being 0.035 – 0.14 mg/m3

� Unpleasant odours (pH < 9)� Neutralisation or acidification can occur gaseous

hydrogen sulphide.Neutralisation or acidification can occur gaseous hydrogen sulphide.

� Corrosion of the effluent drainage system.� Damage to the treatment works and the often

associated high pH.

Reducing agent :Thiourea dioxide/ Formamidine sulfinic acid

� Powerful reducing agent for vat dyes.� Lower MW than sodium dithionite.� Lower sulphite and sulphate load.� More stable than sodium dithionite.� More stable than sodium dithionite.� Cause over-reduction of indanthrone vat dyes.� Glucose or sodium nitrite can’t stabilise.� Very good for reductive colorant stripping.

Reducing agent :Thiourea dioxide/ Formamidine sulfinic acid

� Formamidine-sulfinate in alkaline media is more readily oxidised than dithionite.

� Low water solubility. � Not suitable for continuous process� Not suitable for continuous process

Thiourea dioxide Sodium formamidinesulphinate Sodium hydrogen sulphoxylate

Reducing agent : Sodium formaldehyde-sulfoxylate

� Know as Rongalite C or Formulsol G� Produce from Sodium dithionite with

formaldehyde� More stable than dithionite at lower � More stable than dithionite at lower

temperatures

Reducing agent : Sodium formaldehyde-sulfoxylate

� Can be used to prepare stable pad liquors and print pastes.

� At higher temperatures, they are capable of rapid reduction of vat dyes.rapid reduction of vat dyes.

� Used first in conventional steam fixation of vat prints

Reducing agent : Other sulfoxylates� Sodium acetaldehyde sulfoxylate is suitable

for flash-ageing process.� Zinc formaldehyde sulfoxylate :

- Mono zinc : Water soluble- Mono zinc : Water soluble- Di zinc : Water insoluble

� Calcium formaldehyde sulfoxylate is insolublein water which low tendency to haloing

Mono Zinc formaldehyde sulfoxylateSod. acetaldehyde sulfoxylate Calcium formaldehyde sulfoxylate

Sulfinic acid derivatives : Summary

Advantages(1) Sufficient reduction potential for vat, sulphur or indigo dyeing.(2) Especially suitable for high-temperature dyeing (2) Especially suitable for high-temperature dyeing methods.(3) Good resistance to oxidation by air.

Disadvantages(1) Waste water loading; inhibits biological degradation and leads to a greater oxygen demand(2) Potentially temperature-dependent.

Reducing agent : Hydroxyacetone

� Sulphur-free and biodegradable� Used for vat, sulphur and indigo dyes with

high concentrations of NaOH� Does not over-reduction of indanthrone.� Does not over-reduction of indanthrone.� Give different shades with carbazole dyes,

compared with sodium dithionite

Hydroxyacetone : Summary

Advantages(1) Biologically degradable(2) Ease of dosing in liquid form(3) Very good stability to storage

Disadvantages(1) Does not reach full reduction potential and thus mainly

suitable for indigo and sulphur dyes(2) Persistent odour(3) Limited commercial production

Reducing agent : Glucose

� Characteristic odour preferable than odour of alkaline sulphide bath.

� High alkali concentration is required.� Minimum dyeing temperature of 90–95oC being

necessary.necessary.� High COD level in the effluent.� A lot of by-product ; losing its reducing action.� Should mix with Hydros for higher efficiency

Reducing agent : Dithionite/glucose system

Reducing agent : Dithionite/glucose system

� Potential slightly lower than that of dithionite alone, although glucose has the lowest potential.

� Without the risk of over-reduction.� Without the risk of over-reduction.� Optimal colour yield and good reproducibility� Other glucose binary systems, including

hydroxyacetone or sodium formaldehyde-sulphoxylate as stabiliser gave similar results

Reducing agent : Others

� 2-Mercaptoethanol� Sodium hydrogen sulphite� Iron – Triethanolamine complex � Iron – Gluconic acid complex� Iron – Gluconic acid complex� etc.

Oxidising agents : H2O2

� Use for bleaching on Cotton and other CELs.� Can use as re-oxidising agent for vat dye and

sulphur dyes (easy but low washing fastness)� Environmentally friendly (Very low AOX

values)� Environmentally friendly (Very low AOX

values)� Peroxide bath do not corrosive� Can be used both exhaustion and continuous� Give a good whiteness even without prior

scouring


� Fiber damage (occur by free radical formation especially in the present iron or copper)

� Quality of whiteness (Less attractive tone)� Quality of whiteness (Less attractive tone)� Cost-effectiveness (AOX-containing effuent

are omitted)- 2 times of hypochlorite bleaching in batchwise process

- 6 times of hypochlorite bleaching in continuous process


Effect of pH in bleaching

Optimum

AOX (Adsorbable organic halogen)

AOX values for cotton bleached with various oxidising agents

1.) AOX value of 0.5 mg/l must not be exceeded in waste water released2.) Limit for drinking water of not more than 0.01 mg/l

Oxidising agents for bleaching : H2O2 : Mechanism of bleaching and fibre damage

Oxidising agents : H2O2 : Effect of Fe(III) concentration on rate of decomposition

2.9 g/l H2O2, Sodium Silicate 5 g/l, Magnesium Sulphate 0.2 g/l 95oC, pH 12 (Absence of substrate)

Schematic diagram of catalytic damage occurrence

Oxidising agents : H2O2Desizing of PVA

Oxidising agent : Sodium hypochlorite � Most environmentally damaging of all

bleaching agent with regard to AOX values. May even be banned in some countries.

� Bleached goods are prone to subsequent yellowing on storage.yellowing on storage.

� Substrate must be scoured before bleaching.� Stock solutions of sodium hypochlorite are

unstable and must always be chemically analysed before use.

� Hypochlorite bleaching can not combine with some FWAs and dyestuff.

Oxidising agent : Sodium hypochlorite

� Economical attractiveness� Lower risk of catalytic fibre damage, although

some chemical damage can occur depending on temperature and pHon temperature and pH

� Powerful bleaching action.� High attractive whiteness (Bluish white)

Oxidising agent : Sodium hypochloriteEffect of pH on the composition of sodium hypochlorite solutions

Oxidising agent : Sodium hypochlorite

� After bleaching with hypochlorite it is always necessary to remove residual chlorine present call “Antichlor”

� Bisulphite and hydrogen peroxide are generally � Bisulphite and hydrogen peroxide are generally used for antichlor

Oxidising agent : Sodium chlorite

� Lower AOX values than hypochlorite.� Generally carried out under acidic conditions.

(different from peroxide and hypochlorite)� Risk of chemical damage is low.� Minimal scouring action in acidic bleach

results in lower weight losses hence good � Minimal scouring action in acidic bleach

results in lower weight losses hence good sewability

� Least sensitive to accelerated damage by metallic contamination

� useful for synthetic fibres and particularly important for acrylic fibres.

Oxidising agent : Sodium chlorite

� Toxic and unpleasant chlorine dioxide vapour can be liberated.

� Highly corrosive.No rapid chlorite bleaching process is � No rapid chlorite bleaching process is available.

� Bleached goods gave lower absorbency.� Some dyes and FBAs are destroyed by

chlorite bleaching

Oxidising agent : Sodium chlorite: Effect of pH on the composition of sodium chlorite solutions

Oxidising agent : Peracetic acid

� Peracetic acids can be effective oxidative bleaching agents and, at least potentially, offer an alternative to the environmentally sensitive chlorine bleaches.

Oxidising agent : Dichromate and chromate salts.

� Sodium and Potassium salts are generally used.

� Use combine with acetic acid (pH 4.5-5.5) for re-oxidising sulphur dyesfor re-oxidising sulphur dyes

� Gave the harsher handle and less hydrophilic of dyed fabric

� Can not use in yarn dyes because its decrease the winding property of yarn.

Oxidising agent : Dichromate and chromate salts.

� If combine with Copper salt, Light fastness is improved

� Provide high washing and rubbing fastness.Environmental problem due to Cr3+

� Environmental problem due to Cr3+

� Low cost� Sometimes use as antireduction for disperse dyes

on T/C.

Oxidising agent : Iodate salts

� Potassium iodate is generally used.� For re-oxidise of sulphur dyes, no harsher

handle and high rubbing fastness.� Use combine with Lactic or Acetic acid (pH 3.5-� Use combine with Lactic or Acetic acid (pH 3.5-

5) � Not Formic acid!!� Very high cost.� Maybe use as anti-reduction for disperse dyes

on T/C.

Oxidising agent : Sodium m-nitrobenzene sulphonate

� Use as anti-reduction for reactive, direct and acid dyes.

� Protect the reduction of azo group via heat or unfavorite condition.unfavorite condition.

� Can re-oxidise Vat and Sulphur dyes.

Sequestering agent :

4 important factors for select sequestering agent :� Sequestering power.

� Ability for removal or the neutralizing of harmful metal ions (water hardening substances, heavy metal ions) from the water.

� Complex stability constant.Equilibrium constant of COMPLEX : FREE LIGAND.� Equilibrium constant of COMPLEX : FREE LIGAND.

� Higher electrolyte content and higher temperature can reduce the constant.

� Dispersibility.� Ability to distributed the solid particle in liquid.

� Buffer capacity.� Maintain the pH of solution as narrow or constant.

Typical of sequestering agent

� Aminopolycarboxylate and hydroxy derivative.� Inorganic phosphate� Organic phosphonate� Hydroxycarboxylate� Hydroxycarboxylate� Polyacrylic acid and copolymer.

Aminopolycarboxylate

� Ethylenediaminetetra-acetic acid (EDTA)

� Diethylenetriaminepenta-acetic acid (DTPA)(DTPA)

� Nitrilotriacetic acid (NTA)

Sample of complex

NTA-Ca Complex

EDTA-Ca Complex

DTPA-Ca Complex

Hydroxy derivative of aminopolycarboxylate

� N-(hydroxyethyl) ethylenediaminetriacetic acid (HEDTA)triacetic acid (HEDTA)

� N,N-bis(hydroxyethyl) glycine (DEG)

Metal ion control charge

Stability constants of aminopolycarboxylatechelates at 25°C

Effect of pH on the stability constants at 25°C of Fe(III) and Fe(II)

Effect of pH on the stability constants at 25°C of metal chelates of DTPA

Effect of pH on the stability constants at 25°C of metal chelates of EDTA

Effect of pH on the stability constants at 25°C of metal chelates of HEDTA

Effect of pH on the stability constants at 25°C of metal chelates of NTA

Aminopolycarboxylate :

� Advantages: � high selectivity for heavy metal ions, therefore well-suited as a

regulator for hydrogen peroxide bleach.� good stability at increased temperatures� good alkali resistance.

� Disadvantages:� Disadvantages:� only resistant to oxidizing agents to a limited extent in hot and

strong alkali media� no detergency efficiency and soil carrying capacity; at high alkali

concentrations, � diminishing complexing power; only effective in the

stoichiometric region, therefore large quantities are required.� Alteration of shade and fastness on metal containing dyestuff

molecules.

Inorganic phosphate :

Sample of complex

Inorganic phosphate :

� Advantages: � ability to increase detergency efficiency and soil

carrying capacity of surfactants; complexing power for calcium, magnesium and heavy metal ions.

� Disadvantages: disadvantageous in hot, strong alkali liquors due to � disadvantageous in hot, strong alkali liquors due to their low stability at temperatures of > 80oC and pH > 11 and in strong acid media. In these areas, it is possible that insoluble deposits will form.

� No selectivity for heavy metal ions when calcium and magnesium ions are present.

Organic phosphonate :

� Ethylenediaminetetramethylphosphonicacid (EDTMP)

� Diethylenetriaminepentamethylphosphonicacid (DETMP)

� Nitrilotrimethylphosphonic acid (ATMP)

Organic phosphonate :

� Advantages: � high calcium, magnesium and iron binding capacity� high stability in cold and warm alkali baths and in strong alkali,

oxidizing liquors� very selective effect on polyvalent heavy metal ions

effective in the lower stoichiometric region.� effective in the lower stoichiometric region.

� Disadvantages: � only average detergent and dispersing action� may result in alterations in shade and dyestuff being dissolved

out of the fabric due to the formation of hard complexes with the central atoms of dyestuffs containing metals.

Hydroxycarboxylate :

Hydroxycarboxylate

� Advantages� high sequestering power at limited acid/alkaline

concentration.

� Disadvantages: � Disadvantages: � efficiency is very dependent on pH.

Polyacrylic acid and copolymer :

Other comonomer


Oligomers with a molecular mass of 1200–8000 give optimum sequestering power.


� Advantages: � excellent dispersing properties: solid soil, deposits, husks, etc. are

removed from the fabric and stabilised in the liquor.� high calcium, magnesium and heavy metal binding capacity� lower stoichiometric region (threshold effect) and therefore effective

even when only small quantities are used� Have the effect of delaying crystallization, � Have the effect of delaying crystallization, � do not form hard complexes and therefore do not tend to corrode the

central atoms of dyestuffs containing metals� by varying the monomer components used and the degree of

polymerization, products with specific property profiles can be synthesized.

� Disadvantages:� resistance and efficiency in strong alkali and strong electrolytic liquors

are limited.

Thickener and Migration inhibitor

Relationships between viscosity and shear stress of thickener types

Starch and its derivatives

� Giving high colour yields.� Poor levelness� High amylose content, not stable

British gum

� Produce from heat the dry starch at 135-190oC, 10-24 h� Good stability to alkali and for printing vat dyes.� Suitable for resist printing (high S.C.)

Starch and cellulose ethers :

� Suit for high-speed printing on engraved-roller machine.

Locust bean gum and Guar gum:

� Consist of D-galactomannoglycan. � Resistance wide pH range 3-11.� Locust bean gum must disperse in minimum 45oC water,

but Guar gum in cold water.� Complexes are formed with borates, produce gel.

Alginates :

� Very important for print paste thickener because their ready solubility, even after high-temperature fixation treatments.

� They are especially important for reactive dyes because the extent of interaction is very small.the extent of interaction is very small.

� Stability is good between pH 4-10

Synthetic-polymer thickeners

� Sensitivity to electrolyte� Electrolyte sensitivity

can be reduced by copolymerising with acrylamide.acrylamide.

� Suitable for pigment printing but not for substantive dyes printing.

Poly (acrylic acid)-co-divinylbenzene

Emulsion thickeners :

� O/W emulsion is prefered.� Can be used combine with synthetic thickener.� Viscosity is not change with shear rate.� Suitable with pigment and non-ionic dyes.� Suitable with pigment and non-ionic dyes.

Dyeing accelerator and carriers

� Carrier formulation is generally a nonionic compound of Mr 150–200 containing a benzenoidring system.

� Carrier compounds fall into four main classes� Phenols� Phenols

� o-phenylphenol� Primary arylamines

� N-alkylphthalimide derivatives� Aryl hydrocarbons

� biphenyl, methylnaphthalene, trichlorobenzene� Aryl esters

� methyl salicylate (sometimes mixed with phenyl salicylate), butyl benzoate, diethyl /diallyl phthalate

Why??

� Although polyester or cellulose triacetate fibers are normally dyed at high temperatures, their blends with wool are still dyed at or near the boil. In such cases an auxiliary termed a carrier must be used to promote adequate exhaustion of disperse dyes by the ester fiber within a commercial dyeing time. fiber within a commercial dyeing time.

� Even in high-temperature dyeing, there are occasions when the usual maximum temperature (around 130°C for polyester) cannot be used, as when dyeing qualities of texturized polyester that suffer loss of crimp at 130°C.

� Carriers are used to assist more rapid and complete exhaustion, using smaller amounts than at or near the boil. And sometimes employed to promote migration of unlevel dyeings.

Harmful effects from carrier dyeing

� Residual carrier in the dyebath contributes to effluent pollution and may be environmentally harmful

� Carrier that is volatilised during dyeing or � Carrier that is volatilised during dyeing or subsequent heat setting becomes an atmospheric contaminant

� Residual carrier in the fibre can be a health hazard, as well as causing an unpleasant odour on heating or during storage.

COD and BOD of various carriers

O-phenylphenol

� Generally powerful carriers for polyester, whilst methylnaphthalene and particularly butyl benzoate are less powerful.

� Tend to lower the light fastness of many dyes � Tend to lower the light fastness of many dyes if carrier residues remain in the dyed fibre.

� Less promoting migration� Relatively low volatility in steam and

traditionally has been used in machines open to the atmosphere

Chlorobenzene

� Generally powerful carriers for polyester� Have no effect lower the light fastness of dyes� Readily steam-volatile and are toxic � Difficult to biodegrade� Difficult to biodegrade� Should not be used in machines where

volatilised carrier is likely to condense� May cause ‘carrier spots’� Relatively efficient in promoting migration

Others

� Methylnaphthalene � less powerful for polyester, low toxicity,

moderately biodegradable

� Biphenyl� Biphenyl� Relatively non-toxic to river life but is not readily

biodegradable

� Butyl benzoate � Relatively efficient in promoting migration but less

powerful

Hydrotropic agent

Hydrotropic agent :N type

Hydrotropic agent :O and some S type

Disadvantage of urea

Fixing agent :

Fixing agent for acid dyes on Protein and Nylon

Synthetic tanning agent (Syntan)

Fixing agent for Direct and Reactive dyes on Cellulose.

Typical reactant-fixable direct dye

Classes of cationic agents for fixation of dyed cellulosic fibres

Classes of cationic agents for fixation of dyed cellulosic fibres.

Indosol : Bifunctional, trifunctional and tetrafunctional fixing agents

� Developed for use with a selected range of copper-complex (Indosol) dyes.

� The bifunctional type, which reacts only with the dye, was applied in a fresh bath at about 60oC and gave was applied in a fresh bath at about 60 C and gave fastness to washing at 50oC through the formation of an extensive dye–agent complex within the fibre.

� The trifunctional type additionally forms covalent bonds with cellulose and is applied at 40oC for about 15 minutes, followed by addition of alkali to bring about reaction; this confers a higher degree of fastness to washing at 60oC even with deep shades

Indosol : Bifunctional, trifunctional and tetrafunctional fixing agents

� Tetrafunctional reactant resins confer the highest fastness, even to washing at the boil.

� Applied with an N-methylol reactant such as DMDHEU and an acid-liberating catalyst e.g. magnesium chloride to give a commercial product sold as a cationic reactant resin. resin.

� Applied to the dyeing by padding, and cure at 175 –180oC, result in covalent reaction between the cationic agent and the N-methylol groups as well as crosslinkingof cellulose chains by the N-methylol reactant,

� Not only excellent wet fastness but also improved crease resistance and good dimensional stability.

Textile Chemistry, Textile auxiliaries, สารช่วยทางสิ่งทอ

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