“The Chemistry Of Textiles” Vivimed Labs Europe Ltd ...

“The Chemistry Of Textiles”

Vivimed Labs Europe LtdPhotochromic Colorants

SCI Headquarters, London17th November 2011

Dr. Andy Towns

www.vivimedlabs.com © Vivimed Labs Ltd 2011 All rights reserved

Vivimed Labs Europe Ltd

• Then…–1840s

• Company started life as James Robinson• Natural dyes traded such as logwood– mid to late 20th centuryy

• Rise and fall of sulphur dye business • Moved into:

– hair dyesy– photographic chemicals– fluorescent colorants– fuel markers• Now…

21st century– 21st century• Growth of photochromic dye business• Change of ownership (2008) and name (2010)


Colorants

•• Hair colorantsHair colorants

•• Photochromic dyesPhotochromic dyesyy

•• SemiconductorsSemiconductors


Hair Coloration: “Low Temperature Fibre Dyeing”

Wool and hair are both protein fibres but…

Wool• Traditionally dyed with:

Hair• Conditions restricted:

p

Traditionally dyed with:– acid dyes

• applied at boil• typically pH <4

Conditions restricted:– temperature– pH– timetypically pH 4

– chrome and mordant dyes• often as per acid dyes• heavy metals

– liquor ratio• Performance required:

– limited pre-treatment

– reactive dyes• fixation usually at the boil

• Processes all >1hr

– intensity– level coloration


Hair Coloration: The Challenge

Cortex

Cuticle


Hair Coloration: The Solutions

TemporaryTemporary

SemiSemi permanentpermanentSemiSemi--permanentpermanent

PermanentPermanent


Temporary Hair Dyes: Properties

• Relatively large cationic dyes• Similar to ‘basic’ dyes for acrylic fibre• Some even re-purposed textile dyes• Ad b d t h i fib• Adsorbed to hair fibre• Application in 5 minutes• Used in:Used in:

– shampoos– conditioners– mousses

• Lasts 1-2 washes


Temporary Hair DyesTemporary Hair Dyes: Chromophores

OHN

NOMe

OH

N+

NN

H

NN

O


Me3N+Me

Semi Permanent DyesSemi-Permanent Hair Dyes: Mechanism


Semi-Permanent Hair Dyes: Properties

NHCH CH OHNHCH2CH2OHNO2

N(CH2CH2OH)2

NHCH2CH2OHNONO2

Up to 8-10 washes


NH2

Permanent Hair Dyes: Mechanism and Properties

• Three main components:– primary intermediates (oxidation bases)– couplers– oxidant

• Reactive system:– components mixed– couplers and primary intermediates diffuse into hair fibresp p y– primary intermediates oxidised– couplers react with oxidised primary intermediates to form colorants

• Process typically takes 20-40minProcess typically takes 20 40min• Colorants relatively large in size:

– slow to diffuse out of hair fibrecoloration permanent


– coloration permanent

Permanent (oxidation) dyesPermanent hair dyes - Oxidative Dye ChemistryPermanent Hair Dyes: Chromophores

NH2 NH2

NH2 NH

NH2

NH2

NH2

N

NH2

NH+


2 NH2

Photochromic Dyes

Applications

• Non-textileo e e– Ophthalmic lenses– Plastics– Security printing

T til• Textile– Yarn– Screen printing– Accessories


Photochromism: Definition

Photochromism

• “A reversible colour change induced in a compound driven in one or both directions by the action of electromagnetic radiation”


Photochromism: Types of Dye

• T-type • P-type

– spiropyran – fulgide

– spironaphthoxazine

naphthopyran

– diarylethene

– naphthopyran

most commercially important


Photochromism: Commercial Dyes


Photochromism: Mechanism

NMe Me Me MeUV

ONR

l l

NR

N

O

l d

heat and/orlight

colourlessspironaphthoxazine

colouredphotomerocyanine dye

Exclusively thermal fade : ‘T-type’ photochromism


Photochromism: Mechanism

UVUVUVUV

ΔΔΔΔ


Photochromism: Commercial Dyes

X

O Y

X Y Z l

z

X Y Z colour

H H H weak yellow

H H amino strong yellow

OMe OMe H eak orangeOMe OMe H weak orange

OMe OMe amino strong yellow

amino H amino strong orange


Photochromism: Neutral-coloured Dyes

major kinetic and varied to adjust

OMeMeO

major kinetic andcolour effects

X Y

varied to adjustcolour & kinetics

O OR2N

Me

Me

2

z

selected toconfers extramajor kinetic and

minor colour effectsselected to

tune kineticspeak andneutral colour


Photochromism: Limitations

• Medium– certain polymerscertain polymers

• Photostability– use of additives

• Mixtures– activation– fatigue– fatigue

• Application method– mass coloration– screen printing

• Reversibility


Shade DevelopmentSemiconductor Dyes: Textile Applications

• Wearable devices– genuinely smart fabrics– integration of existing technologies

• Organic semiconductorsOrganic semiconductors– flexible substrates– printable circuitry

Organic ThinOrganic ThinFilm Transistors

(OTFT)itechfuture.com


itechfuture.com

Semiconductors: Functional Colorants

OOO

OO

gate

OTFTO

Si(R)3drain

3 source

substrate

Si(R)3


Si(R)3

Further Information

• Photochromic dyes– Corns Partington and Towns “Industrial Organic PhotochromicCorns, Partington and Towns, Industrial Organic Photochromic

Dyes”, Coloration Technology 125 (2009) 249-261

• Hair colorants– Morel and Christie, “Current Trends in the Chemistry of

Permanent Hair Dyeing”, Chem. Rev. 111 (2011) 2537-2561

• Organic electronicsg– Anthony, “Functionalised Acenes and Heteroacenes for Organic

Electronics”, Chem. Rev. 106 (2006) 5028-5048

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“The Chemistry Of Textiles” Vivimed Labs Europe Ltd ...

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