WO2009121148A1

WO2009121148A1 - Dye comprising functional substituent

Info

Publication number: WO2009121148A1
Application number: PCT/AU2009/000417
Authority: WO
Inventors: Nino Malic; Richard Alexander Evans
Original assignee: Advanced Polymerik Pty Ltd
Priority date: 2008-04-03
Filing date: 2009-04-03
Publication date: 2009-10-08

Abstract

Functionalized dye compounds are provided comprising a dye moiety and a substituent comprising a multivalent linker covalently bonding the dye moiety to at least two distinct functional groups and further provided are polymeric compositions containing the dye compounds and methods for their preparation.

Description

DYE COMPRISING FUNCTIONAL SUBSTITUENT

Field

[0001] The invention relates to substituted dyes and in particular dyes having a substituent comprising two or more functional groups, to compositions containing the dyes and to methods of preparation of the dyes and compositions.

Background

[0002] Dyes and in particular photochromic dyes are used in compositions and environments which call for a rage of physical and chemical properties. For example, many dyes undergo fatigue or loss of colour through degradation caused by oxidation, UV degradation or the presence of reactive components in the composition. For example, a drawback to the widespread commercial use of organic photochromic compounds is the loss of their ability to change colour as a result of prolonged repeated exposure to U. V. light, i.e. the organic photochromic compounds lose their photochromism or their ability to change colour and revert to their original colourless state.

[0003] Another problem encountered with dyes is a difficulty in achieving compatibility of the dye with the host which it is used to colour. In extreme cases poor compatibility can lead to phase separation. In less severe cases dyes may agglomerate resulting in unevenness or loss of colouring. In some cases differences in properties between the host and dye can result in migration of the dye to the surface of a host composition; a process commonly referred to a blooming.

[0004] Photochromic and thermochromic dyes present particular problems as their transformation between different colour states (generally coloured and colourless) may be influenced to a significant extent by the nature of the host. In particular the rate at which photochromies or thermochromics undergo such a change (generally referred to as the rate of fade) is significantly influenced by the host so that the transition is relatively rapid in liquids and relatively slow in hard solids. [0005] It is advantageous to control the rate at which photochromic polymeric compositions colour when exposed to radiation and fade on cessation of this exposure. In many situations, it is important to provide rapid colouring and fading kinetics, particularly for lenses and spectacles. In some polymers however, the rate of colouration and fade is slow so that a compromise needs to be made in the components and properties of the substrate to enhance the rate of colouration and fade. For applications such as spectacles or structural panels, abrasion resistance and hardness are important. This trade off between rate of transformation and hardness produces a dilemma for manufacturers between toughness and photochromic efficiency. In polymeric lenses many photochromies exhibit a slower rate of fade than is desirable. It is desirable to be able to control the fade kinetics of photochromic compounds in a wide range of media.

[0006] Our copending International Application No PCT/AU2003/001453 (WO 2004/041961 ) discloses photochromic compounds in which the photochromic moiety is functionalised to contain one or more pendant polymeric substituent groups. The polymeric substituent chains specifically described are generally C₂ to C₄ alkylene, C₂ to C₄ haloalkyleneoxy and alkyleneoxy and hydrocarbylsiloxane. While the photochromies disclosed in this copending application allow dramatic changes in the kinetics as a result of the polymeric functional group, the polyalkoxy chains and polysiloxane chains offer limited control of fade kinetics, and additional and more versatile options are desirable to allow more precise tailoring of kinetics.

[0007] Our copending International Applications published as WO 2005/105874 and WO 2005/105875 describes photochromic compounds containing polymer substituents which are reactive with the host polymer during curing of the host so that the photochromic becomes tethered to the matrix.

[0008] Our copending International Application published as WO2006/024099 relates to photochromic compounds having a polymer substituent which comprises a carbon backbone and pendant functional groups which may be used to control the fade speed. The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Summary

[0009] The invention provides a functionalized dye compound comprising a dye moiety and a substituent comprising a multivalent linker covalently bonding the dye moiety to at least two functional groups. The multivalent moiety is preferably bound to at least the dye moiety and two functional agents which are different from one another.

[0010] The functional groups may be selected from a range of stabilizing and compatibility improving groups, groups reactive with a host matrix or functional groups which provide for or modify other physical or chemical properties of the dye compound or its nanoenvironment.

[0011] In one embodiment there is provided a polymeric dye composition comprising a matrix selected from the group consisting of polymers of Tg of at least 5O⁰C and monomer compositions which on curing provide polymers of Tg of at least 5O⁰C; and a functionalized dye as hereinbefore described.

[0012] The polymeric dye composition may comprise a functional group which is reactive with the matrix to thereby covalently bond the dye to the matrix.

[0013] Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps. [0014] Where used herein the term alk used alone or in words such as alkoxy, alkylthio, alkanoyl and in the term alkyl, unless indicated to the contrary, includes groups Ci to C₂o alkyl, preferably Ci to Cio alkyl and more preferably Ci to C₆ alkyl.

[0015] Where used herein the term substituted alkyl and substituted alkoxy includes alkyl and alkoxy substituted with one or more substitutents selected from the group consisting of halo, hydroxy, alkoxy, haloalkoxy, aryloxy, carbocyclic and heterocyclic.

[0016] Where used herein the term aryl includes monocyclic and dycyclic aromatic and heteroaromatic compounds of from 5 to 10 ring members. Heteroaromatic compounds may include from 1 to 3 heteroatoms selected from oxygen, nitrogen and sulfur. Preferred examples of aryl include phenyl, pyridyl, indolyl, benzopyranyl and the like.

[0017] Where used herein the term halo preferably means chloro or fluoro. The term halo, when used as a prefix such as in haloalkyl, haloalkoxy or haloaryl includes the presence of one or more halogen substituents.

[0018] Where used herein the term substituted aryl includes aryl substituted with one or more substitutents selected from the group consisting of halo, hydroxy, akyl, alkoxy, alkoxycarbonyl, carboxyl and nitrile.

[0019] Where used herein the term acyl includes alkanoyl such as Ci to C₂o alkanoyl and aroyl such as benzoyl.

[0020] Where used herein the term substituted acyl includes acyl substituted with one or more substituents selected from the group consisting of halo, hydroxy, alkoxy, alkyl, aryl and substituted alkoxy. Detailed Description

[0021] Where used herein the term comprise and variations of the word, such as "comprising" and "comprises", is not intended to exclude other additives, components, integers or steps.

[0022] Where used herein the term cycloalkyl includes aliphatic groups containing from 1 to 3 rings and a total of from 4 to 20 carbon atoms.

[0023] Where used herein the term substituted cycloalkyl may include one or more substitutents selected from the group consisting of halo, hydroxy, alkoxy and aryl.

[0024] Where used herein the term heterocyclic includes aliphatic groups containing from 1 to 20 carbon atoms and from 1 to 3 heteroatoms independently selected from oxygen, nitrogen and sulphur and up to 3 rings.

[0025] Where used herein the term substituted heterocyclic includes heterocyclic groups substituted with one of more substitutents selected from the group halo, hydroxy, alkoxy and aryl.

[0026] The functionalized dyes of the invention comprise a dye moiety (which is preferably a photochromic), at least one multivalent linker and at least two functional groups (which are preferably different from each other) linked to the dye via the multivalent linker.

[0027] In a preferred embodiment the compounds of the invention are of formula I

wherein PC is a photochromic dye moiety, L is a multivalent linker, R is a functional group, B is a functional group distinct from R, t is an integer and is 1 or 2 and x is an integer selected from 1 and 2. The sum of x and t is preferably 2 or three.

[0028] Examples of functional groups include one or more selected from the group consisting of antioxidants, ultraviolet absorbers, light stabilizers, infrared absorbers antistatic agents, host compatibilizers, further dye substituents which are preferably selected from photochromies, substituents which provide a high refractive index in a transparent host matrix, substituents which modify the nanoenvironment of the dye to modify their behavior (for example the rate of fade in the case of photochromic dyes), gas barrier polymers and groups reactive with the host matrix to tether the functionalized photochromic to a host matrix.

[0029] Illustrative antioxidants can include derivatives of hindered phenolic antioxidants, such as 3-(3',5'-di-t-butyl-4'-hydroxy-phenyl)propionic acid, 3-(3'-t-butyl-5'-methyl-4'- hydroxy-phenyl)propionic and the like, and their acid chlorides; and derivatives of sulfur- containing antioxidants such as monododecyl 3,3'-thiobispropionate, monooctadecyl 3,3'- thiobispropionate, and their acid chlorides.

[0030] Illustrative ultraviolet absorbers can include derivatives of benzotriazole ultraviolet absorbers, such as 3-[3'-(2"H-benzotriazol-2"-y- l)-4'-hydroxyphenyl]propionic acid, 3-[3'- (2"H-benzotriazol-2"-yl)-5'-meth- yl-4'-hydroxy-phenyl]propionic acid, 3-[3'-(2"H- benzotriazol-2'-yl)-5'-eth- yl-4'-hydroxyphenyl]propionic acid, 3-[3-(2"H-benzo-triazol-2"- yl)-5'-t-bu- tyl-4'-hydroxyphenyl]propionic acid, 3-[3'-(5"-chloro-2"H-benzotriazol-2"-- yl)- 5'-t-butyl-4'-hydroxyphenyl]propionic acid, 3-[3"-(2"H-benzotriazol-2"- '-yl)-4"-hydroxy-5"- (1 ',1 '-dimethybenzyl)phenyl]propionic acid, 3-[3"-(2"H-benzotriazol-2"-yl)-4"-hydroxy-5"- (1 ",1 ",3",3"-tetramethylbuty- l)phenyl]propionic acid and the like, and their acid chlorides.

[0031] Examples of other ultraviolet absorbers can include derivatives of triazine ultraviolet absorbers, such as 2-[4'-[(2"-carboxypropioxy-3"-dod- ecyloxypropyl)oxy]-2'- hydrophenyl]-4,6-bis (2',4'-dimethylphenyl)-1 ,3,5-tr- iazine, 2-[4'-[(2'-phthalyloxy-3'- dodecyloxypropyl)oxy]-2'-hydroxy-phenyl]- -4,6-bis(2',4'-dimethylphenyl)-1 ,3,5-triazine and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides; benzoic acid ultraviolet absorbers such as benzoic acid, p-aminobenzoic acid and p- dimethylaminobenzoic acid, cinnamic acid ultraviolet absorbers such as cinnamic acid and p-methoxycinnamic acid, salicylic acid, and the like; and their acid chlorides. Examples of yet another group of ultraviolet absorbers include derivatives of infrared absorbers, such as tris(t-octyl-naphthalo)(carboxyl-phthalo)cyanine-vanadium oxide complex and N-(o-carboxyl-p-dibutylaminophenyl)-N,N',N'-tris(p-dibutylaminophenyl)-p- phenylenediamine hexafluorophosphate.

[0032] Examples of light stabilizers can include derivatives of hindered amine light stabilizers, such as 2,2,6,6-tetramethyl-4-piperidinol, 1 , 2,2,6, 6-pentamethyl-4-pipehdinol and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides.

[0033] Examples of antistatic agents can include derivatives of antistatic agents, such as polyethylene glycol monomethyl ether, poly(ethylene glycol-propylene glycol) monomethyl ether, poly(ethylene glycol-propylene glycol)monobutyl ether, N, N- diethylaminoethanol, N,N-diethylaminopropanol- , N,N-diethyl-aminoethoxy-polyethylene glycol and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides; 3-diethylaminopropionic acid, 2,3-epoxypropyl-dimethylamine, and 2,3-epoxypropyl- trimethylammonium chloride.

[0034] One group of stabilizers are described in US Patent 5216103 the contents of which are herein incorporated by reference. A range of reactive stabilizers containing hindered phenol groups are disclosed in US patent 5292850 the contents of which are incorporated herein by reference.

[0035] Examples of nitroxide compounds which may be useful in the present invention also include any compound having a

or a salt thereof. These compounds can be represented broadly by the formula:

wherein R₃ is as defined above, and R₄ and R₅ combine together with the nitrogen to form a heterocyclic group. The atoms in the heterocyclic group (other than the N atom shown in the formula) may be all C atoms or may be C atoms as well as one or more N, O and/or S atoms. The heterocyclic group preferably has 5 or 6 total atoms. The heterocyclic group may be preferably a pyrrole, imidazole, oxazole, thiazole, pyrazole, 3- pyrroline, pyrrolidine, pyridine, pyrimidine, or purine, or derivatives thereof, for example.

[0036] Further compounds which may be useful in the present invention also include those wherein R₄ and R₅ themselves comprise a substituted or unsubstituted cyclic or heterocyclic groups.

[0037] Still further compounds which may be useful in the present invention also include oxazolidine compounds capable of forming an oxazolidine-1 -oxyl.

[0038] The antioxidant may be of formula formula:

wherein R₁ is --CH₃ ; R₂ is --C₂H₅, --C₃H₇, --C₄H₉, --C₅ Hn, -C₆Hi₃, --CH₂--CH(CH₃)₂, -- CHCH₃ C₂ H₅, or ~(CH₂)₇ --CH₃, or wherein R₁ and R₂ together form spirocyclopentane, spirocyclohexane, spirocycloheptane, spirocyclooctane, 5-cholestane, or norbornane; R₃ is --O-- or --OH, or a physiologically acceptable salt thereof which has antioxidant activity. The antioxidant may be linked to the multivalent linker via one of R¹ to R³.

[0039] The types of polymers which may be used in the function of compatibility agents of fade modifiers will depend on the properties required of dyes, particularly in the case of photochromies, the host material and the desired level of the functional properties. Specific examples of polymer groups include polyethylene, polypropylene, poly(ethylene- propylene) and poly(ethylene-propylene-.α olefins); polyether polymers such as polypropylene glycol, poly(ethylene glycol-propylene glycol), (polyethylene glycol)- (polypropylene glycol) block copolymer and polytetramethylene glycol; polyorganosiloxane polymers such as polydimethylsiloxane, aliphatic polyesters such as polybutylene adipate and polyethylene sebacate; polyesters, for example, aromatic polyesters such as polyethylene isophthalate, polybutylene terephthalate and polyneopentyl terephthalate; polyamides such as 6-nylons and 6,6-nylons; polyvinyl polymers such as polystyrene, styrene copolymers and polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral; (meth)acrylic (co)polymers such as acrylate ester (co)polymers, methacrylate ester (co)polymers and acrylic compound-styrene copolymers; polysilicone polymers; polyurethane resins; polyurea resins; epoxy resins; melamine resins; cellulose resins; chitosan resins; copolymers of two or more of the monomers making up the above-described polymers; and block copolymers formed of two or more of the above-described polymers. [0040] Specific examples of polymers can be found in International publications WO 2004/041961 , WO 2005/105874, WO 2005/105875 and WO2006/024099 the contents of which are herein incorporated by reference.

[0041] The polymer groups preferably comprise at least 5 monomeric units and more preferably at least 10 units. The molecular weight of the polymeric units is preferably at least 200 and more preferably at lest 250.

[0042] In the case of photochromic dyes a particularly preferred group of polymers for speeding up the rate of colouration and fade of photochromies are polymers comprising polyether groups, polmers containing polyorganosiloxanes and comb polymers comprising siloxane or ester side chains such as disclosed in WO2006/024099.

[0043] In some cases polymer groups such as polysiloxanes speed up the fade of polymers in a rigid host and yet compromise the compatibility of the dye with the host. In such cases it may be preferred to provide at least two polymeric functional substituents including a substituent which is adapted to provide the desired nanoenvironment for the photochromic dye moiety and a further substituent adapted to improve the compatibility of the substituted dye with the host. In the case of a low Tg substituent such as a polyalkylene glycol or polysiloxane the is a potential for phase separation of the photochromic in harh non-polar matrices such as polyolefins or nylons. In such instances the propensity of the photochromic to phase separate may be reduced by use of an additional substituent which is non-polar such as a long chain aliphatic substituent such as a fatty aliphate (C₆ to C₃o fatty aliphate containing from 0 to 3 double bonds such as 1 or 2 double bonds).

[0044] The polymeric groups when present in the compounds of the invention comprise at least three monomer units more preferably at least five monomer units and still more preferably at least seven monomer units. Typically the molecular weights of the polymeric groups will be at least 250 such as at least 500, at least 1000 or at least 2000 and preferably less than 20000 such as less than 10000. [0045] Functional groups which increase refractive index include sulfur, bromine and chlorine containing compounds. Dithiols and polythiols are preferred. Examples of dithiols of use in the present invention include 9,10- anthracenedimethanethiol, 1 ,11 -undecanedithiol, 4-ethylbenzene-1 ,3-dithiol, 1 ,2- ethanedithiol, 1 ,8-octanedithiol, 1 ,18-octadecanedithiol, 2,5-dichlorobenzene-1 ,3-dithiol, 1 ,3-(4-chlorophenyl)propane-2,2-dithiol, 1 ,1 -cyclohexanedithiol, 1 ,2-cyclohexanedithiol, 1 ,4-cyclohexanedithiol, 1 ,1 -cycloheptanedithiol, 1 ,1 -cyclopentanedithiol, 4,8- dithiaundecane-1 ,11 -dithiol, dithiopentaerythritol, dithiothreitol, 1 ,3-diphenylpropane-2,2- dithiol, 1 ,3-dihydroxy-2-propyl 2',3'-dimercaptopropyl ether, 2,3-dihydroxypropyl 2', 3'- dimercaptopropyl ether, 2,6-dimethyloctane-2,6-dithiol, 2,6-dimethyloctane-3,7-dithiol, 2,4-dimethylbenzene-1 ,3-dithiol, 4,5-dimethylbenzene-1 ,3-dithiol, 3,3-dimethylbutane- 2,2-dithiol, 2,2-dimethylpropane-1 ,3-dithiol, 1 ,3-di(4-methoxyphenyl)propane-2,2-dithiol, 3,4-dimethoxybutane-1 ,2-dithiol, 10,11 -dimercaptoundecanoic acid, 6,8- dimercaptooctanoic acid, 2,5-dimercapto-1 ,3,4-thiadiazole, 2,2'-dimercaptobiphenyl, 4,4'- dimercaptobiphenyl, 4,4'-dimercaptobibenzyl, 3,4-dimercaptobutanol, 3,4- dimercaptobutyl acetate, 2,3-dimercapto-1 -propanol, 1 ,2-dimercapto-1 ,3-butanediol, 2,3- dimercaptopropionic acid, 1 ,2-dimercaptopropyl methyl ether, 2,3-dimercaptopropyl 2', 3'- dimethoxypropyl ether, 3,4-thiophenedithiol, 1 ,10-decanedithiol, 1 ,12-dodecanedithiol, 3,5,5-thmethylhexane-1 ,1 -dithiol, 2,5-toluenedithiol, 3,4-toluenedithiol, 1 ,4- naphthalenedithiol, 1 ,5-naphthalenedithiol, 2,6-naphthalenedithiol, 1 ,9-nonanedithiol, norbornene-2,3-dithiol, bis(2-mercaptoisopropyl)ether, bis(11 -mercaptoundecyl)sulphide, bis(2-mercaptoethyl)ether, bis(2-mercaptoethyl)sulphide, bis(18- mercaptoctadecyl)sulphide, bis(8-mercaptooctyl)sulphide, bis(12- mercaptodecyl)sulphide, bis(9-mercaptononyl)sulphide, bis(4-mercaptobutyl)sulphide, bis(3-mercaptopropyl)ether, bis(3-mercaptopropyl)sulphide, bis(6- mercaptohexyl)sulphide, bis(7-mercaptoheptyl)sulphide, bis(5-mercaptopentyl)sulphide, 2,2-bis(mercaptomethyl)acetic acid, 1 , 1 -bis(mercaptomethyl)cyclohexane, bis(mercaptomethyl)durene, phenylmethane-1 ,1 -dithiol, 1 ,2-butanedithiol, 1 ,4- butanedithiol, 2,3-butanedithiol, 2,2-butanedithiol, 1 ,2-propanedithiol, 1 ,3-propanedithiol, 2,2-propanedithiol, 1 ,2-hexanedithiol, 1 ,6-hexanedithiol, 2,5-hexanedithiol, 1 ,7- heptanedithiol, 2,6-heptanedithiol, 1 ,5-pentanedithiol, 2,4-pentanedithiol, 3,3- pentanedithiol, 7,8-heptadecanedithiol, 1 ,2-benzenedithiol, 1 ,3-benzenedithiol, 1 ,4- benzenedithiol, 2-methylcyclohexane-1 ,1-dithiol, 2-methylbutane-2,3-dithiol, ethylene glycol dithioglycolate or ethylene glycol bis(3-mercaptopropionate). Mention may be made, among trithiols, of 1 ,2,3-propanetrithiol, 1 ,2,4-butaneththiol, trimethylolpropane trithioglycolate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol trithioglycolate, pentaerythritol tris(3-mercaptopropionate), 1 ,3,5-benzeneththiol and 2,4,6-mesitylenetrithiol.

[0046] Examples of polythiols of use in the compositions of the present invention include neopentanetetrathiol, 2,2-bis(mercaptomethyl)-1 ,3-propanedithiol, pentaerythritol tetrakis(3-mercaptopropionate), 1 ,3,5-benzenetrithiol, 2,4,6-toluenetrithiol, 2,4,6- methyleneththiol and polythiols corresponding to the formulae:

(HSCH2CH2COOCH2)3CC2H5 (TMPT), and 4-mercaptomethyl-3,6-dithia-1 ,8- octanedithiol.

[0047] In one embodiment of the invention the functional groups comprise one or more additional dye materials which are preferably photochromic dye materials. In one embodiment at least one of the functional groups comprise a fucctional group polymerizable with a host matrix such as a polymer matrix. The compounds may be tethered to the host matrix by forming the host matrix in the presence of the photochromic comprising the multivalent linker and at least one reactive functional group which will copolymerize with the monomer composition used to form the host matrix. It will be understood that the reactive group may be selected depending on the nature of the monomer composition and method used for polymerization of the monomer.

[0048] Examples of preferred polymerizable reactive groups may be selected from the group consisting of amino; alkylamino (including mono and di-alkylamino); hydroxyl; thio; mercapto; epoxy; carbamate; alkylhalo; unsaturated groups (such as acryloyl, methacryloyl, acryloyloxy and methacryloyloxy), maleimides; the group of formula - SiX¹X²X³ wherein X¹, X² and X³ are independently selected from the group consisting of hydrogen, halogen, hydrocarbyl and hydrocarbyloxy and wherein at least one of X¹, X² and X³ is selected from hydrogen, halogen and hydrocarbyloxy; dithioester (-S-C=S-R); trithiocarbonate (-S-C=S-S-R); dithiocarbamate (-S-C=S-NRR); xanthate (-S-C=S-O-R); carboxylic acids; carboxylic esters; and Ci to C₆ alkyl substituted with a group selected from hydroxy, thio, amino, alkyl amino, carboxyl, (C₁ to C₆ alkoxy)carboxyl, acryloyl, methacryloyl, acryloyloxy and methacryloyloxy.

[0049] In one embodiment the reactive group is a radical capping group adapted to be reversibly cleaved from the compound under activating conditions to provide a reactive radical. Such radical groups will be known to those skilled in the art for use in living free radical polymerisation and include groups such as dithioester (-S-C=S-R); trithiocarbonate (-S-C=S-S-R); dithiocarbamate (-S-C=S-NRR); xanthate (-S-C=S-O-R); carboxylic acids; carboxylic esters and nitroxide.

[0050] Preferably halogen is chloro; preferred hydrocarbyl is Ci to C₆ alkyl and phenyl; preferred hydrocarbyloxy is C₁ to C₆ alkoxy. [0051] The reactive group may be an unsaturated group. Most preferably the unsaturated group is selected from the group consisting of (meth)acryloyl, (meth)acryloyloxy, allyl, allyloxy, maleimides, styryl and norbornenyl. The reactive group may also be of formula SiX¹X²X³ wherein X¹, X² and X³ are independently selected from the group consisting of hydrogen, C₁ to C₄ alkyl, halogen and C₁ to C₄ alkoxy and at least one of X¹, X² and X³ is selected from hydrogen, halogen and C₁ to C₄ alkoxy.

[0052] Particularly preferred examples of the group B in formula Na and Nb are of formula Ng to III.

wherein: X' as defined for formula Na and lib;

X" is as defined for formula Na and lib; preferably selected from the group consisting of Ci to C₄ alkylene; where Y is oxygen or sulphur; w is the number of hydroxyl or thiol groups at the terminal end of the reactive group; p is selected from 0 and 1 ; q is selected from 0 and 1 ;

J is hydrogen or C₁ to C₄ alkyl (preferably hydrogen or methyl);

R is an oligomer as defined;

R' is hydrogen, C₁ to C₆ alkyl or substituted (C₁ to C₆) alkyl; and

R" is hydrogen (C₁ to C₆) alkyl or substituted C₁ to C₆) alkyl.

[0053] The compound of the invention contains at least one multivalent linker which covalently links the dye to at least two functional groups which are different from each other. The linker group will typically be derived from a compound containing one or more types of reactive groups selected from nucleophilic and electrophilic groups such as acid groups and their derivatives such as acid chlorides, anhydrides and the like, alcohols, thiols, amine and vinyl groups.

[0054] Specific examples of liker groups include phosphine, polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and both linear and branched polyethylenimine; primary amines such as methylamine, hydroxyethylamine, octadecylamine and polymethylenediamines such as hexamethylenediamine; polyaminoalkylarenes such as 1 ,3,5-tris(aminomethyl)benzene; tris(aminoalkyl)amines such as tris(aminoethyl)amine; heterocyclic amines such as imidazolines and piperidines; and various other amines such as hydroxyethylaminoethylamine, mercaptoethylamine, morpholine, piperazine, amino derivatives of polyvinylbenzyl chloride and other benzylic polyamines such as tris(1 ,3,5- aminomethyl)benzene. Other suitable nucleophilic likers include polyols such as the aforementioned pentaerythritol, ethylene glycol and polyalkylene polyols such as polyethylene glycol and polypropylene glycol; 1 ,2-dimercaptoethane and polyalkylene polymercaptans; thiophenols, and phenols. Polyols particularly hydroxyl phenols are preferred for the preparation of polyether substituents. Benzylic polyamines such as tris(1 ,3,5-aminomethyl)benzene; alkanolamines such as ethanolamine; and aziridine and derivatives thereof such as N-aminoethyl aziridine.

[0055] Examples of suitable linkers include the CrC₄ alkyl esters of various polycarboxylic acids such as benzene tricarboxylic acid, oxalic acid, terphthalic acid and various other carboxylic acids represented by the formula I:

wherein R which when t is more than one may be the same or different is selected from the group consisting of hydroxyl, lower alkoxy, amino, substituted amino, acyl and substituted acyl particularly halo acyl such as 2-bromoisobutryl;

R¹ is selected from hydroxyl and leaving groups such as chloro;

Y is hydrocarbyl or a hydrocarbon polyl wherein the hydrocarbon radical is alkyl, aryl, cycloalkyl, alkylene, arylene, cycloalkylene, and corresponding trivalent, tetravalent, pentavalent and hexavalent radicals of such hydrocarbons; and z is a whole number from 1 to 6, t is a whole number from 1 to 6 and z plus t is at least 3.

[0056] The group Y may be aromatic or aliphatic and is preferably aromatic.

[0057] In a preferred embodiment z is one and is reacted with the dye moiety and t is at least 2 and more preferably is 2 or 3. Still more preferably the groups R are of different reactivity, for example by being distinct groups or positioned unevenly with respect to the group (CO)R¹ In one embodiment the group Y is a benzene ring and z is one and t is two and the groups R are disposed in the 2 and 4-positions or 2- and 5-positions relative to the group (CO)R¹.

[0058] In a preferred embodiment the at least one substituent on the photochromic (PC) is selected from the group of formula Na and Hb:

wherein in the formula Na to lib:

U is a covalent linker to the polymeric group (Poly) and is a bond or a chain containing up to four units defined by any one of formulae Nc to Nf

O

X' is selected from the group consisting of oxygen, sulfur, amino, alkylamino, Ci to C₄ alkylene, Ci to C₄ alkyleneoxy, Ci to C₄alkyleneoxy(Ci to C₄alkyleneoxy) and carbonyl (Ci to C₄ alkylene);

X" is selected from the group consisting of oxygen, sulfur, amino, alkylamino, Ci to C₄ oxyalkylene, C₁ to C₄ oxyalkylene(C₁ to C₄ oxyalkylene) and (C₁ to C₄ alkylene) carbonyl; n is an integer from 1 to 3; p which when there is more than one may be the same or different is 0 or 1 ; q is 0 or 1 ;

B is a further functional group; t is 0, 1 or 2 and preferably the sum n+t is no more than 3; and

Poly is the position of the covalently bonded low Tg polymer.

[0059] The low Tg polymer may comprise a polymer group such as described in WO 2004/041961 , WO 2005/105874, WO 2005/105875 or WO2006/024099.

[0060] The preferred dyes are photochromic dyes.

[0061] The photochromic moiety may be chosen from a wide range of photochromic moieties known in the art. The most appropriate photochromic moieties for use in the compounds used in accordance with the invention are photochromies which undergo a molecular isomerism such as a cis-trans isomerism or pericyclic reaction such as 6ττ, -6 atom, 6 π, - 5 atom processes and [2+2], [4+4] or [4+2] cyclo additions. The compositions of the invention (and in particular the polymeric substituent chains) are believed to provide a nanoenvironment to provide a desired environment which may lead to a controlled speed of transformation between the colour-producing chromophore and the colourless state of the photochromies. Thus, transformations may be made faster or slower than a reference dye of identical electronic structure (but without the polymer substituent) depending on the nature of the attached polymer.

[0062] Photochromic compounds comprising a polymeric substituent in accordance with the invention may comprise a photochromic moiety selected from the group consisting of: chromenes such as those selected from the group consisting of naphthopyrans, benzopyrans, indenonaphthopyrans and phenanthropyrans; spiropyrans such as those selected from the group consisting of spiro(benzindoline) naphthopyrans, spiro(indoline)benzopyrans, spiro(indoline)- naphthopyrans, spiroquinopyrans, and spiro(indoline)pyrans and spirodihydroindolizines; spiro-oxazines such as those selected from the group consisting of spiro(indoline)naphthoxazines, spiro(indoline)pyridobenzoxazines, spiro(benzindoline)pyhdobenzoxazines, spiro(benzindoline)naphthoxazines and spiro(indoline)- benzoxazines; fulgidies, fulgimides; anils; perimidinespirocyclohexadienones; diarylperfluorocyclopentenes; diarylcyclopentenes; diheteroarylcyclopentenes; diheteroarylperfluoro- cyclopentenes; stilbenes; thioindigoids; azo dyes; diarylperfluorocyclopentenes; and diarylethenes.

[0063] Examples of photochromic moieties may be selected from the group consisting of fulgide photochromic compounds, chromene photochromic compounds and spiro- oxazine photochromic compounds. A wide range of photochromic compounds of each of the classes referred to above have been described in the prior art and having regard to the teaching herein the skilled addressee will have no difficulty in preparing a wide range of photochromic polymeric substituent adducts. Examples of chromene photochromic compounds, fulgide photochromic compounds and spiro-oxazine photochromic compounds are described in US Patent No. 5776376.

[0064] The most preferred photochromic moieties are the chromenes and spiro-oxazines, specifically spiroindolene aroxazines. The photochromic compounds of the invention comprising stabilizing agent functional groups generally have an improved fatigue resistance (that is they have a longer lifetime) when compared with the corresponding unsubstituted photochromic. Generally the light exposure time for stabilized photochromic compounds of the present invention which is required to cause 50% fatigue will be at least 20%, longer preferably at least 50% longer and most preferably at least 100% longer than the corresponding unsubstituted dye.

[0065] The compounds of the invention may be prepared by a range of methods which will be readily apparent to those skilled in the art having regard to the compounds.

[0066] Generally the method will comprise reacting a linking group of formula I to react an elctrophilic group present in the linker with an electron rich substituent, particulate and alcohol ether or amine group provided in the dye. The linker may be provided with functional groups prior to or subsequent to attachment to the linker. The linker groups for attachment to the functional groups may be selected for reaction with the functional group. For example the groups may be of type R shown in formula I.

[0067] In one embodiment a polymeric group is grown by step growth polymerization or living free radical polymerization from one or more groups in the linker of formula:

— O(CO)C(CH3)₂Br

[0068] A specific example of a suitable linking group of this type is 3,5-Bis(2- bromoisobutyryloxy)benzoyl chloride.

[0069] A preferred aspect to this invention is the ability to be able to selectively attach different functional groups (including the photochromic moiety) to the multivalent linker. The functional groups may be attached in any order but attachment of the photochromic dye last is practically the preferred method. Selective reaction of each functional group to the linker is desirable as it prevents multiple reaction of one functional group with the linker molecule. This selectivity may be obtained through the use of protecting group methodology as used by practicing organic chemists. [0070] Alternatively, the choice of multivalent linker may allow selective reaction without protecting groups. Non-limiting examples of such multivalent linkers that display selective reactivity are amino 2-hydroxy benzoic acids or dihydroxybenzoic acids such that one hydroxy group is in the 2 position and the amino or other hydroxy group is in a position other than 6. For example, in 5-amino-2-hydroxy benzoic acid the amino group maybe reacted exclusively with an acid chloride in aqueous conditions leaving the hydroxy group untouched. Then the 2-hydroxy groups can be reacted with a different acid chloride in tetrahydrofuran with pyridine. Finally the carboxylic acid may be converted to an acid chloride and reacted with a hydroxy compound. This can of course be extended to trihydroxy benzoic acids although it is likely two hydroxy may have near equivalent reactivity. This is illustrated below. Aliphatic linker molecules displaying points of differential reactivity are also possible.

[0071] In the example above the photochromic compound would most likely be the R₃ group in order to minimize manipulations involving the dye. Thus R₁ and R₂ may separately consist of groups that manipulate switching speed, stability or compatibility of the dye, or selection of other functional groups to modify properties. Thus a combination of properties of the dye may be manipulated at once.

[0072] A similar non limiting example that may display selective reactivities without the need for protecting groups are shown below.

[0073] A non-limiting example for the synthesis of a photochromic hetero Y-branched system incorporates the use of a substituted cyclic anhydride. (2-Dodecen-1 -yl)succinic anhydride may be reacted with a mono-functionalized oligomer/polymer, such as a mono carbinol (hydroxyl) end-terminated poly(dimethylsiloxane), giving a carboxylic acid functionalized species with the molecular structure (X), depicted below. The carboxylic acid functionality of compound (X) can then be converted to an acid chloride giving species (Xl), which can now further react with a hydroxyl-functionalized photochromic dye, giving the desired photochromic species (XII) having two different pendant oligomeric species (dodecenyl chain and poly(dimethylsiloxane) chain) attached through a Y-branch. Thus substituted cyclic anhydrides represent a simple method to prepare photochromic dyes with two different substitutents to the same point on the dye.

[0074] Another non-limiting example for the synthesis of a photochromic hetero Y- branched system incorporates the use of 2,2-Bis(hydroxymethyl)propionic acid as a linker moiety. It is firstly reacted with a mono-acid halide functionalized oligomer/polymer, such as the poly(dimethylsiloxane) compound (XIII) depicted below, which results in a mixture of mono and di-acylated products, of which the desired mono-acylated product (XIV) may be isolated and purified by column chromatography. The use of a large excess of the 2,2-Bis(hydroxymethyl)propionic acid starting material with respect to the acid chloride (XIII) may facilitate the formation of predominantly the mono-acylated product. Alternatively, it may be desirable, for enhancement of overall yields and ease of purification, to use a strategy involving protecting group chemistry to firstly protect only one of the two hydroxyl functionalities of the 2,2-Bis(hydroxymethyl)propionic acid starting material prior to reaction with an acid halide. The remaining hydroxyl group in the resulting compound (XIV) is then reacted with a second different acid halide, resulting in the carboxylic acid functionalized species (XV). The second different acid halide can be, as a non-limiting example, 2-bromoisobutyryl bromide, resulting in a 2-bromoisobutyrate ester functionality which can act as an initiating moiety for use in ATRP (Atom Transfer Radical Polymerization). Another non-limiting example of a second different acid halide is (meth)acryloyl chloride, which results in a methacrylate functionality in the photochromic system that can be bound into a (meth)acrylate-based radically polymerizable matrix formulation such as those used to manufacture optical lens articles. The carboxylic acid functionalized species (XV) is subsequently turned into the acid chloride and reacted with a hydroxyl-functionalized photochromic dye, giving the desired photochromic species (XVI), comprising a photochromic dye having two different functionalities/moieties attached via a Y-branch.

[0075] In yet another non-limiting example for the synthesis of a photochromic hetero Y- branched system incorporates the use of a commercially available mono-dihydroxyl end- terminated poly(dimethylsiloxane), compound (XVII), which is reacted with a functionalised acid chloride in such a way as to maximize the amount of mono-acylated product versus the undesired di-acrylated product. The mono-acylated product (XVIII) is then isolated and purified by column chromatography and further reacted with succinic anhydride to form the carboxylic acid functionalized species (XIX), which is converted to the acid chloride and subsequently reacted with a hydroxyl-functionalized photochromic dye, giving the desired photochromic species (XX) consisting of a photochromic dye having two different functionalities/moieties covalently attached via Y-branching.

[0076] In yet another non-limiting example for the synthesis of a photochromic hetero Y- branched system incorporates the use of a commercially available mono-epoxy end- terminated poly(dimethylsiloxane), compound (XXI), which can be reacted with a nucleophilic species, in this case a spirooxazine photochromic dye bearing a secondary amine (piperazyl) functionality (XXII). This results in the ring opening of the epoxide, forming a hetero Y-branched photochromic system (XXIII) where the photochromic dye is linked to both a poly(dimethylsiloxane) oligomer/polymer and a reactive hydroxyl group through a Y-branch. This hydroxyl group is a functional group in its own right and use to react with host matix components ushc as isocyanates in polyurethane matrices. Alternatively the hydroxyl group may not be react with a matrix (for example one cured by free radical chemistry).

[0077] In a preferred embodiment of the invention the compound comprises a further polymeric group which may be part of the same chain as a barrier polymer substituent or may be a distinct substituent on the photochromic moiety by virtue of a branched linker. The polymeric substituent may be selected from the group consisting of polyether oligomers, polyalkylene oligomers, polysubstituted alkylene) oligomers, polyfluroalkylene oligomers, polyfluoroalkylether oligomers, PO^dI(C₁ to C₁₀ hydrocarbyl)siloxane oligomers, polysilicic acid oligomers (silicates) or derivatives thereof, poly (ZSi(OH)₃) oligomers and derivatives thereof, poly (ZSiCI₃) oligomers and derivatives thereof, poly (ZSi(OMe)₃) oligomers and derivatives thereof, and mixtures thereof wherein Z is an organic group. Preferably Z is selected from the group consisting of hydrogen, alkyl, optionally substituted alkyl, haloalkyl, cycloalkyl, optionally substituted cycloalkyl, hydroxyl, amino, optionally substituted amino, alkoxy, aryloxy, aryl, optionally substituted aryl, carboxylic acid and derivatives thereof. A particularly preferred subset of these later oligomers are colloquially known as Polyhedral Oligomehc Silsesquioxanes (POSS). Compounds that contain a photochromic moiety and a POSS oligomer can display crystalline state photochromism.

[0078] The more preferred low Tg polymers are polydi(Ci to Cio hydrocarbyl)siloxane oligomers particularly polydialkylsiloxanes such as polydimethylsiloxane and polyether oligomers particularly polyalkyleneoxy oligomers such as polyethyleneglycol. The moleculer weight of the low Tg segment is preferably at least 250. [0079] Examples of suitable polymeric groups include groups of formula Ilia:

-(X)p(R)_q - R^' lll(a) wherein:

X is selected from oxygen, sulfur, amino such as C₁ and C₆ alkyl amino, C₁ to C₄ alkylene (preferably methylene); p is 0 or 1 ; q is the number of the monomer units R¹ in said oligomer and is preferably at least 5;

R, which may be the same or different, are selected from the group consisting of:

C₂ to C₄ alkylene such as ethylene, propylene and butylene; chloro(C₂ to C₄ alkylene) such as vinylchlohde, vinylidenedichloride and chloropropene; vinyl acetate (optionall hydrolyzed);vinyl alcohol; ethylene-vinyl alcohol copolymer; acrylonitrile; copolymers of two or more thereof and copolymers of at least one thereof with a comonomer such as acrylate and/or methacrylate comonomers;

R is selected from hydrogen, C₁ to C₆ alkyl and C₁ to C₆ haloalkyl, hydroxyl, optionally substituted amino, optionally substituted aryl carboxylic acid and derivatives thereof and preferably R is selected from the group consisting of hydrogen, C₁ to C₆ alkyl, unsaturated C₂ to C₂₀aliphatic, substituted amino, optionally substituted aryl and alkyl and aryl esters of carboxyl.

[0080] In one embodiment of the invention an additional polymeric group is present which is a poly(substituted alkylene) polymer comprising a plurality of monomer units of formula NIb

wherein

R¹, which is independently selected for each of said plurality of monomer units, is selected from the group consisting of hydrogen, fluoro, alkyl, hydroxy alkyl, and alkoxy; R² in each of said monomer units is independently selected from the group consisting of, alkoxy, aryl, aryloxy, heterocyclic arylalkyl, alkylaryl, carboxyl, and the group of formula:

wherein R⁸ is selected from the group consisting of alkyl, substituted alkyl, carbocyclic, substituted carbocyclic, heterocyclic, substituted heterocyclic; and X is selected from the group consisting of a bond, oxygen, sulphur and the group NR⁷' wherein R⁷ is selected from the group consisting of hydrogen, alkyl, substituted alkyl, aryl and substituted aryl, carbocyclic, substituted carbocyclic, heterocyclic and substituted heterocyclic; wherein preferably at least one of R⁷' and R⁸ is other than hydrogen and the group of formula:

wherein p is from 1 to 20, q is 0 or 1 , Z is selected from the group consisting of C₂ - C₄ alkylene, dialkylsilyl, diarylsilyl and diaryloxysilyl; L is a bond or a linking group such as Ci to C₆ alkylene, aryl, alkaryl and aralkyl; and Y is a terminal group selected from the group consisting of hydrogen, alkyl, hydroxyl and alkoxy, alkoxyalkoxy, hydroxyalkoxy and aryloxy, tri-(Ci to C₆ alkyl)silane, di(Ci to C₆ alkyl)phenyl silane;

R² , which is independently selected for each of said plurality of monomer units, is hydrogen and R² and R² may together form a group of formula

wherein X is selected from the group consisting of oxygen, surfur and the group NR⁷ wherein R⁷ is selected from the group of hydrogen, alkyl, aryl, substituted alkyl and substituted aryl.

[0081] The polymer comprising the monomeric unit of formula I may be a homopolymer or copolymer. It may be a copolymer of two or more units of formula I or a copolymer of at least one unit of formula I and one or more comonomer units derived from unsaturated compounds. Where the polymer is a copolymer suitable comonomer units may include one or more distinct units of formula III or comonomers of formula IVb:

wherein

R³, R⁴, R⁵ and R⁶ are independently selected from the group consisting of hydrogen, halogen, alkyl, substituted alkyl, aryl, substituted aryl and haloalkyl. The copolymer may be a random or block copolymer.

t is from 2 to 500, preferably 2 to 200, more preferably 2 to 100 and most preferably from 5 to 50 and w is from 0 to 500, preferably 0 to 100 and more preferably 0 to 50.

[0082] Wherein when the polymer is a copolymer the distinct units may be present as blocks or randomly distributed.

[0083] The invention further provides a photochromic comprising at least one polymeric substituent formed by a chain growth polymerization method. A particularly preferred method of chain growth is by living polymerisation, particularly living free radical polymerization. [0084] The compounds of the invention may be incorporated in polymerizable compositions used to form the host matrix so that they become bound within the polymerized host. In one embodiment of the invention the photochromic compound of the invention comprises a terminal group (the group B in the compound of formula lib or the group Y' in the compound of the invention of formula iiib) which is reactive with the polymerizable composition during curing. For example, the polymerizable group may be an unsaturated group which becomes tethered to the host polymer during curing of the host composition. The group may be an alcohol, acid, amine or other group for reacting with co-reactive functional groups in a host monomer. In this embodiment the compound of the invention becomes chemically bound with the polymeric substituent forming a tether bound (particularly by covalent bonds) to the host.

[0085] In an embodiment the invention provides a composition for forming a photochromic light transmissible article the composition comprising: a polymerizable composition comprising a monomer component including a crosslinking monomer; and a photochromic polymer reactive with the monomer component during curing.

[0086] The polymerizable composition may comprise one or more of monomers, prepolymers, crosslinking monomers and binders.

[0087] In one embodiment a photochromic polymer thus comprises a photochromic moiety and at least one pendant group comprising a functional group reactive with a monomer composition for forming a photochromic polymeric article.

[0088] The photochromic monomer may be incorporated into an existing polymer, for example, by reactive processing of the polymer during extrusion or other processing step. Examples of reactive processing include grafting and transesterification.

[0089] In a further aspect the invention provides a photochromic composition comprising a polymeric substrate and photochromic compound comprising a photochromic moiety and at least one polymeric substituent comprising a carbon backbone and pendant functional groups. The polymeric substrate may be in the form of a coating composition, a polymerizable composition or rigid polymer such as rigid polymers used in optical applications.

[0090] The polymeric photochromic may be prepared in a number of ways such as: i). Growth of the polymeric substituent from a photochromic dye having a suitable initiation group. This initiation event may occur from a reaction of a living radical polymerization control group on the photochromic dye such as a RAFT group, ATRP initiation group , iniferter group or alkoxyamine as non-limiting examples; ii). Growth of the polymer from a precursor to the photochromic dye and subsequent formation of the photochromic moiety from the precursor group; iii). Preparation of the polymeric portion comprising polymer and subsequent joining of the photochromic moiety be any suitable organic synthesis procedure ; and iv). Copolymerization of a monomer comprising the photochromic moiety with monomers for providing a polymeric substituent such as a low Tg polymer or gas barrier polymer.

[0091] Polymerisation of a polymer substituent may be carried out by radical polymerization, ionic polymerization (anionic or cationic) or by group transfer polymerization.

[0092] In a preferred embodiment the polymerization is by radical polymerization such as living or other radical polymerization and in a particularly preferred embodiment the polymerization is conducted by living free radical polymerization (also referred to as step growth radical polymerization. Specific examples of living free radical polymerization include RAFT, ATRP or Iniferter mediated living free radical polymerization. Each of these methods is known in the art and described in our copending International Publication WO2005/105875. RAFT mediated living free radical polymerization is particularly preferred. RAFT polymerization of one or more vinylic monomers is described for example, in detail in WO-A-98/01478.

[0093] A RAFT polymerization system is basically a free-radical polymerization system which additionally comprises a specific chain transfer agent, the "RAFT agent", usually a thiocarbonyl-thio compound, as described more particularly in WO-A-98/01478. The RAFT agent is preferably a compound of the following formula:

wherein

Z is selected from hydrogen, fluorine, chlorine, optionally substituted alkyl, optionally substituted aryl. optionally substituted heterocyclyl, optionally substituted alkylthio, optionally substituted dialkylamino, optionally substituted alkoxyl, optionally substituted phenoxy, -COOR", -COOH, -O₂CR", -CONR"₂), -CN, -P(=0)OR"₂, and - P(=O)R"₂]-, wherein R" is selected from optionally substituted C₁-C₁₈ alkyl, C₂-C₁₈ alkenyl, aryl, heterocyclyl, aralkyl, alkaryl wherein the substituents are independently selected from the group that consists of epoxy, hydroxy, alkoxy, acyl, acyloxy. carboxy (and salts), sulfonic acid (and salts), alkoxy- or aryloxy-carbonyl, isocyanato, cyano, silyl. halo, and dialkylamino; and

R is selected from optionally substituted alkyl; an optionally substituted saturated, unsaturated or aromatic carbocyclic or heterocyclic ring; optionally substituted alkylthio; optionally substituted alkoxy; optionally substituted dialkylamino.

[0094] Preferred thiocarbonylthio compounds useful for the purposes of the present invention include, for example, dithiobenzoic acid benzyl ester; dithiobenzoic acid 1 - phenyl-ethyl ester; dithiobenzoic acid 1 -methyl-1 -phenyl-ethyl ester; acetic acid 1 - thiobenzoylsulfanyl-ethyl ester; dithiobenzoic acid 1-(4-methoxyphenyl)-ethyl ester; thiobenzoylsulfanyl-acetic acid ethyl ester; 2-methyl-2- thiobenzoylsulfanyl-propionic acid ethyl ester; dithiobenzoic acid tert. -butyl ester; dithiobenzoic acid cyano-dimethyl-methyl ester (=2-(2-cyanopropyl) dithiobenzoate); dithiobenzoic acid 1 ,1 ,3,3-tetramethyl-butyl ester; dithiobenzoic acid 1-(4-chloro-phenyl)-1 -methyl-ethyl ester; 4-chloro-dithiobenzoic acid 1 -methyl-1 -phenyl-ethyl ester; naphthalen-1 -carbodithionic acid 1 -methyl-1 -phenyl- ethyl ester and 4-cyano-4-methyl-4-thiobenzoylsulfanyl-butyric acid. 2-(2-cyanopropyl) dithiobenzoate), butyl 2-(2-cyanopropyl) trithiocarbonate, butyl 1 -(1 -cyanoethyl) trithiocarbonate are mostly preferred.

[0095] When the photochromic polymer is formed by copolymerization of a photochromic monomer with a gas barrier and optionally further unsaturated monomers the photochromic monomer may be of formula:

wherein

R'" is hydrogen or methyl; p is from 1 to 20, q is 0 or 1 ;

Z is selected from the group consisting of C₂ - C₄ alkylene, dialkylsilyl, diarylsilyl and diaryloxysilyl;

L is a bond or a linking group such as Ci to C₆ alkylene, aryl, alkaryl and aralkyl; and

(PC) is a photochromic moiety.

[0096] The invention further provides a living free radical process for preparing a photochromic polymer providing gas barrier stabilisation of the photochromic the method comprising living free radical polymerisation of free-radically polymerizable monomers comprising vinylic monomers for forming a gas barrier polymer, said process comprising forming a mixture of: (a) One or more vinyl monomers; optionally a further vinyl monomer such as an acrylate and/or methacrylate monomer;

(b) a living free radical chain transfer agent such as a RAFT, ATRP or lniferter living free radical mediation agent; and

(c) a photochromic reagent comprising a living free radical initiation group or radically polymerisable vinyl group; and

reacting the mixture at a temperature of more than 50^QC, preferably more than 60^QC and more preferably more than 70^QC.

[0097] In order to initate a living polymerization from a substituted photochromic dye, a living radical polymerization control group must be present . such groups include and are not limited to RAFT groups, ATRP initiation groups , iniferter and alkoxyamines. For example below shows an ATRP initiation group attached to the dye . RAFT groups can be similarly introduced . One method is to react the ATRP group with a trithiocarbonate anion or dithioester anion/^"

here

[0098] The compound of the invention comprises a photochromic moiety. Preferred examples of photochromic moieties include the spirooxazine of formula V, chromene of formula XX, fulgide/fulgamide of formula XXX or an azo dye of formula XL. Formulae V, XX, XXX and XL are described below with reference to examples wherein the group L[(B)t](R)x which is referred to is the group of formula Ia:

wherein L is a multivalent linker, R is a functional group, B is a functional group distinct from R, t is an integer and is 1 or 2 and x is an integer selected from 1 and 2 (the sum of x and t is preferably 2 or three) and wherein the group is preferably of formula Na or lib as hereinbefore defined.

[0099] Preferred spiro-oxazines of the general formula III can be suitably used.

[0100] In the general formula V, R³, R⁴ and R⁵ may be the same or different and are each an alkyl group, a cycloalkyl group, a cycloarylalkyl group, an alkoxy group, an alklyleneoxyalkyl group, an alkoxycarbonyl group, a cyano, an alkoxycarbonyl alkyl group, an aryl group, an arylalkyl group, an aryloxy group, an alkylenethioalkyl group, an acyl group, an acyloxy group or an amino group, R⁴ and R⁵ may together form a ring, and R³, R⁴ and R⁵ may optionally each have a substituent(s). The substituent(s) can includes (include), besides the above-mentioned groups, halogen atom, nitro group, heterocyclic group, etc.

[0101] The group represented by moiety Va:

is a substituted or unsubstituted bivalent aromatic hydrocarbon group or a substituted or unsubstituted bivalent unsaturated heterocyclic group. The group represented by moiety Vb:

is a substituted or unsubstituted bivalent aromatic hydrocarbon group or a substituted or unsubstituted bivalent unsaturated heterocyclic group. Specific examples of the bivalent aromatic hydrocarbon group are groups of 6 to 14 carbon atoms derived from benzene ring, naphthalene ring, phenanthrene ring, anthracene ring or the like. Specific examples of the bivalent unsaturated heterocyclic group are groups of 4 to 9 carbon atoms derived from furan ring, benzofuran ring, pyridine ring, quinoline ring, isoquinoline ring, pyrrole ring, thiophene ring, benzothiophene ring or the like.

[0102] The substituents can be the same groups as mentioned above with respect to R³, R⁴ and R⁵. In particular, a group represented by:

-NR⁶R⁷

(wherein R⁶ and R⁷ are each an alkyl group, an alkoxy group, an allyl group or the like, each of which may be substituted; and R⁶ and R⁷ may be bonded and cyclized with each other to form a nitrogen-containing heterocyclic ring) is preferable from the standpoint of high density of its developed colour in the initial photochromic performance.

[0103] In a particularly preferred embodiment the photochromic compounds of the invention are of formula Vl

wherein R³, R⁴, R⁵, R⁸ R⁹, R¹⁰ and R¹¹ are independently selected from the group consisting of hydrogen, alkyl, halo, haloalkyl, cycloalkyl, cycloarylalkyl, hydroxy, alkoxy, alkyleneoxyalkyl, alkoxycarbonyl, aryl, arylalkyl, aryloxy, alkylenethioalkyl, acyl, acyloxy, amino, NR⁶R⁷, cyano and the group L[(B)t](R)x wherein at least one of R³, R⁸ and R⁹ is the polymeric substituent group of formula L[(B)t](R)x wherein L, R and n are hereinbefore defined and wherein there is more than one L[(B)t](R)x group in the groups R⁸, R³, R⁴ and R⁵ and one or more R groups may optionally be linked together to form one or more bridging polymeric substituent. The m is an integer and may be 0, 1 or 2 wherein m is 2 the groups may be independently selected.

[0104] In the compound of formula Vl the total of the number of monomer units in polymeric substituents, (R)_n, is at least 7 and preferably at least 12.

[0105] More preferably, the substituent R³ is selected from the group consisting of alkyl, cycloalkyl, cycloarylalkyl, alkyleneoxyalkyl, aryl, arylalkyl alkylenethioalkyl, and the group L[(B)t](R)x and more preferably R³ is selected from alkyl, cycloalkyl, cycloarylalkyl, alkenyloxyalkyl, aryl, arylalkyl, and the group L[(B)t](R)x and preferably R⁴ and R⁵ are indefinitely selected from alkyl, cycloalkyl and aryl.

[0106] R⁸ and R⁹ are independently selected from hydrogen and L[(B)t](R)x; R¹⁰ and R¹¹ are independently selected from the group consisting alkyl, cycloalkyl, cycloarylalkyl, alkoxy, -NR⁶R⁷, cyano, alkyleneoxyalkyl, alkoxycarbonyl, aryl, arylalkyl, aryloxy, alkylenethioalkyl, aryl aryloxy and amino and most preferably R¹⁰ and R¹¹ are independently selected from alkyl, cycloalkyl, alkoxy, NR⁶R⁷ and cyano; and m is 0 or 1.

[0107] Examples of the preferred fused aromatic ring groups of formula Va include Va(i);

wherein R⁹ and R¹¹ are as hereinbefore defined.

[0108] Examples of the preferred fused aromatic ring group of formula 1Mb include Vb(i),

Vb(N), Vb(iii) and Vb(iv).

[0109] Specific examples of the group of formula Va(i) include

[0110] Specific examples of the group of formula 1Mb include

[0111] One particularly preferred embodiment of the compounds of formula Vi has the formula Via

[0112] The more preferred compounds of formula Via are compounds wherein R⁴ and R⁵ are preferably independently selected from the group consisting of Ci to C₄ alkyl and the group wherein R⁴ and R⁵ link together to form a cycloalkyl of from 4 to 6 carbon atoms.

[0113] R⁸ and R⁹ are independently selected from the group consisting of hydrogen, halogen, cycloalkyl, cycloaryl alkyl, hydroxy alkoxy, cyano, alkenyloxyalkyl, alkoxycarbenyl, aryl, aralkyl, aryloxy, alkylene, thioalkyl and the polymeric substituent of formula L[(B)t](R)x wherein L, R and n are as hereinbefore defined; [0114] R¹⁰ and R¹¹ are independently selected from the group consisting of hydrogen, halogen, cycloalkyl, cycloarylalkyl, alkoxy, cyano, alkenyloxyalkyl, alkoxycarbonyl, aryl, arylalkyl, acyloxy and alkylenethioalkyl. Most preferably R¹⁰ and R¹¹ are hydrogen; and at least one of R⁸ and R⁹ is the group L[(B)t](R)x wherein the total number of monomer units in R is at least 10 and more preferably at least 12.

[0115] In order to provide an increase in fade rate of the photochromic in a polymer (preferably a polymer of high Tg) article, the size of the polymer chain must be greater than a certain size. The minimum size will depend on the nature of the polymeric substituent chain and the linking group. It is believed that the fade is significantly accelerated where a polymer chain may adopt a conformation in which a portion of the chain is adjacent the oxazine ring.

[0116] The more preferred compounds of the invention are of formula (VIb)

where the substituents are hereinbefore described and even more preferably

R³ is Ci to C₄ alkyl; C₃ to C₆ cycloalkyl, aryl, alkylaryl, arylalkyl and L[(B)t](R)x; R^5a and

R^5b are independently selected from Ci to C₆ alkyl C₃ to C₆ cycloalkyl, aryl;

R⁸ and R⁹ are selected from hydrogen, hydroxy, Ci to C₆ alkoxy; R¹⁰ is selected from the group hydrogen, hydroxy, Ci to C₆ alkoxy -NR⁶R⁷ wherein R⁶ and R⁷ are independently hydrogen, Ci to C₆ alkyl and wherein R⁶ and R⁷ may together form a divisional hydrocarbon chain of 4 to 6 carbon atoms.

[0117] As we have discussed above, in order to maximise the rate of colouration and fade in polar and non-polar polymers it is preferred that one of R³, R⁸ and R⁹ is L[(B)t](R)x comprising at least 10, more preferably at least 12 monomer units and the other two of R³, R⁸ and R⁹ are other than L[(B)t](R)x where L[(B)t](R)x contains 7 monomer units.

[0118] In compounds where more than one of R³, R⁸ and R⁹ is L[(B)t](R)x comprising at least 7 monomer units, the effect on the rate of colouration and fade will depend to some extent on the polymeric substituent and type of polymer. In cases where the polymer and polymeric substituents are compatible, the rate of fade may be decreased and when the polymeric substituent and resin are less compatible, the effect may be less or fade may be increased.

[0119] We have found that for compounds of formula Vl a (preferably VIb) if R⁸ and R⁹ are shorter chains or smaller substituents they are also useful in controlling the rate of fade though to a more limited extent.

[0120] In a further embodiment, the invention therefore provides compounds of formula Via (preferably VIb) wherein R⁸ and R⁹ are each selected from groups of formula I and groups of formula L[(B)t](R)x as hereinbefore defined and the group LR¹¹ wherein R¹¹ is lower alkyl, lower haloalkyl, lower polyalkyleneoxy aryl and aryl(lower alkyl). The term lower is used to mean up to 6 carbon atoms in the chain and preferably up to 4.

[0121] In yet another embodiment we provide an intermediate for preparation of compounds of the invention, the intermediate being of formula IVa and more preferably VIb wherein R⁸ and R⁹ are selected from XH wherein X is hereinbefore defined. Preferably R⁸ and R⁹ are the same.

[0122] Compounds of the invention may be prepared by reaction of intermediates Vila or VIIb and VIII.

[0123] One method for preparing compounds of the invention comprises reacting a methylene indolene of formula Vila or Fishers base or indolium salt of formula VIIb where J is halogen, particularly the iodide salt, wherein R¹³ is R⁹ and R¹⁴ is R³ with a nitrosohydroxy compound of formula VIII to provide a compound of the invention of formula Vl.

[0124] Alternatively, a methylene indolene of formula Vila or indolium salt of formula VIIb may be reacted with a nitrosohydroxy compound of formula VIII wherein R¹² and R¹³ are independently selected from the group consisting of hydrogen and -XH and at least one of R¹² and R¹³ is -XH to provide an intermediate of formula IX.

and reacting the compound of formula VIII with a compound of formula IX JL[(B)t](R)x X wherein J is a leaving group to form a compound of formula Vl wherein at least one of R^ε and R⁹ are the group L[(B)t](R)x.

[0125] Alternatively or in addition the compound of formula IV wherein R³ is L[(B)t](R)x may be prepared by reacting the compound of formula Vila or VIIb with a compound of formula X to provide a compound of formula Vila and VIIb where R¹⁴ is L[(B)t](R)x and reacting the compound of formula Via or VIb with a compound of formula VIII to provide a compound of formula IV wherein R³ is L[(B)t](R)x.

[0126] Specific examples of compounds of formula X, include J L[(B)t](R)x where J is chlorine, L a linker is of formula Na to lib where p is O and R is any one of the the barrier polymer.

[0127] Compounds of formula Xl

having a wide variety of the fused aromatic groups B may be prepared using the intermediate of formula VIIc.

[0128] The fused aromatic group B and its substituents may be chosen to provide the desired colour of the photochromic compound. Such compounds provide a versatile method of preparation of rapid fade spiroindolineoxazines. [0129] Examples of suitable substituted methylene indolene compounds of formula Va and Vb include 5-amino indolene compounds described by Gale & Wiltshire (J. Soc. Dye and Colourants 1974, 90, 97-100), 5-amino methylene compounds described by Gale, Lin and Wilshire (Aust. J. Chem. 1977 30 689-94) and 5-hydroxy compounds described in Tetrahedron Lett. 1973 12 903-6 and in US Patent 4,062,865.

[0130] One of the preferred groups of photochromies are the spiropyrans. Examples of spiropyrans include compounds of formula XIX and XX

wherein in XIX the groups X, Y, Z and Q may be substituents including where one or more thereof form a carbocyclic ring optionally fused with aryl and the substituents R²³ and R²⁴ may be present in any ring; and wherein

B and B are optionally substituted aryl and heteroaryl; and

R²², R²³ and R²⁴ are independently selected from hydrogen; halogen; Ci to C₃ alkyl; the group L[(B)t](R)x; and the group of formula COW wherein W is OR²⁵, NR²⁶R²⁷, piperidino or morpholino wherein R²⁵ is selected from the group consisting of Ci to C₆ alkyl, phenyl, (Ci to C₆ alkyl)phenyl, Ci to C₆ alkoxyphenyl, phenyl Ci to C₆ alkyl, (Ci to C₆ alkoxy)phenyl, Ci to C₆ alkoxy C₂ to C₄ alkyl and the group L[(B)t](R)x; R²⁶ and R²⁷ are each selected from the group consisting of Ci to C₆ alkyl, C₅ to C₇ cycloalkyl, phenyl, phenyl substituted with one or two groups selected from Ci to C₆ alkyl and Ci to C₆ alkoxy and the group L[(B)t](R)x; R²² and R²³ may optionally form a carboxylic ring of 5 or 6 ring members optionally fused with an optionally substituted benzene and wherein at least one of the substituents selected from the group of substituents consisting of B and B¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷ is the group L[(B)t](R)x.

[0131] When R and R are carbocyclic a preferred compound is of formula XX(d)

where R , R^^s and R^⁹ are as defined for Pr above

[0132] Preferably B and B' are independently selected from the group consisting of aryl optionally substituted with from 1 to 3 substituents, heteroaryl optionally substituted with from 1 to 3 substituents. The substituents where present are preferably selected from the group consisting of hydroxy, aryl, C₁ to C₆) alkoxyaryl, (C₁ to C₆) alkylaryl, chloroaryl (C₃ to C₇) cycloalkylaryl, (C₃ to C₇) cycloalkyl, (C₃ to C₇) cycloalkoxy, (C₁ to C₆) alkyl, aryl (C₁ to C₆) alkyl, aryl (C₁ to C₆) alkoxy, aryloxy, aryloxyalkyl, aryloxy (C₁ to C₆) alkoxy, (C₁ to (C₆) alkylaryl, (C₁ to C₆) alkyl, (C₁ to C₆) alkoxy, amino, N-(C₁ to C₆) alkyl amino, ipirazino, N-aryl piperazino, indolino, piperidino, aryl pipersillins, morpholino, thiomorpholino, tetrahydro quinolino.

[0133] NR²⁹R³⁰ wherein R²⁹ and R³⁰ are independently selected from the group selected from C₁ to C₆ alkyl, phenyl, C₅ to C₇ cycloalkyl and the group wherein R²⁹ and R³⁰ form a linking group of 4 or 5 linking groups comprising methylene groups and optionally containing one or two hetero atoms and optionally further substituted by C₁ to C₃ alkyl and the group L[(B)t](R)x.

R²² is selected from the group consisting of hydrogen, C₁ to C₆ alkyl; COW where W is OR²⁵ wherein R²⁵ Ci to C₆ alkyl; and the group NR²⁶R²⁷; wherein R²⁶ and R²⁷ are independently Ci to C₆ alkyl; and the group L[(B)t](R)x. Particularly referred naphthopyran compounds are of formula XX(a)

[0134] Or the corresponding compound in which the oxygen of the pyran ring is attached to the 2-position of the naphthylene group, i.e. the core of the photochromic is of formula:

wherein

R²⁰ and R²¹ are independently selected from the group consisting of hydrogen, hydroxy, alkoxy, amino, alkylamino, dialkylamino and L[(B)t](R)x;

R²² is the group COW where W is Ci to C₆ alkoxy or the group L[(B)t](R)x;

R²³ is selected from the group consisting of hydrogen and NR²⁶R²⁷ where R²⁶ are independently selected from the group consisting of C₁ to C₆ alkyl and where R²⁶ and R²⁷ may together form an alkylene group of 4 to 6 carbon atoms;

R²⁴ is hydrogen or the group L[(B)t](R)x; and wherein at least one of R²² and R²⁴ is L[(B)t](R)x.

[0135] Compounds of formula XX wherein R²³ and/or R²⁴ comprise the polymeric substituent group L[(B)t](R)x may be prepared from a suitably substituted acetophenone, benzophenone or benzaldehyde of formula XXI(a). In this process the compound of formula XXI (a) (or a polyhydroxy compound where more than one substituent is required) is reacted with an polymeric substituent esterified toluene sulfonate of formula XXI to provide the corresponding polymeric substituent ether of formula XXI(b). The aromatic polymeric substituent ether of formula XXI (b) is reacted with an ester of succinic acid such as the dialkyl succinate of formula XXI(c). A Stobbe reaction produces the condensed half ester of formula XXII which undergoes cyclo dehydration in the presence of acidic anhydride to form the naphthalene polymeric substituent ether of formula XXIII. This compound of formula XXIII may be reacted with acid such as hydrochloride acid and an anhydrous alcohol such as methanol to form the corresponding naphthol shown in formula XXIV which is in turn coupled with the propargyl alcohol of formula XXV to form the polymeric substituent substituted naphthopyran of the invention of formula XX(b).

[0136] Alternatively, compounds of formula XX(c) in which at least one of the geminal phenyl groups is substituted by a polymeric substituent may be prepared from the benzophenone of formula XXI(f). In this process the benzophenone substituted with the appropriate hydroxyl groups is reacted with the polymeric substituent ester of toluene sulfonate of formula XXI (e) to form the corresponding polymeric substituent substituted benzophenone of formula XXI(g). The corresponding propargyl alcohol of formula XXV(a) is prepared from the benzophenone by reaction with sodium acetylide in a solvent such as THF. This propargyl alcohol of formula XXV(a) is coupled with the appropriate substituted naphthol of formula XXIV(b) to form the polymeric substituent substituted naphthopyran of formula XX(c).

[0137] A further option for forming polymeric substituent substituted pyrans of the invention of formula XX(d) in which the polymeric substituent is present in the 5-position of the naphthopyran may utilise the corresponding carboxylated naphthol of formula XXIII(a). In such a process the naphthol of formula XXIII(a) is reacted with an appropriate polymeric substituent of formula XXI(d) (particularly where linking group L comprising oxygen) to provide a polymeric substituent ester of formula XXI V(a). The polymeric substituent naphthol ester of formula XXIV(a) may be reacted with propargyl alcohol of formula XXV to provide the naphthol of formula XX(d) in which the polymeric substituent is present in the five position.

[0138] In a further alternative compounds of formula XX wherein R²² comprises the polymeric substituent L[(B)t](R)x may be formed by reacting a compound of formula XX(e) with an acid chloride or anhydride substituted polymeric substituent to provide a compound of formula:

[0139] Examples of fulgides and fulgimides include compounds of formula XXX and more preferably XXXa:

wherein

Q is selected from the group consisting of optionally substituted aromatic, optionally substituted heteroaromatic (where said aromatic/heteroaromatic may be mono or polycyclic aromatic/heteroaromatic);

R³⁰, R³² and R³³ are independently selected from the group consisting of a Ci to C₄ alkyl, Ci to C₄ alkoxy phenyl, phenoxy mono- and di(Ci-C₄) alkyl substituted phenyl or phen(d-C₄)alkyl and R³² and R³² optionally together form a fused benzene which may be further substituted;

A is selected from the group consisting of oxygen or =N-R³⁶, in which R³⁶ is CrC₄ alkyl or phenyl,

B is selected from the group consisting of oxygen or sulfur; R³⁴ and R³⁵ independently represents a CrC₄ alkyl, phenyl or phen(Ci-C₄) alkyl or one of R³⁴ and R³⁵ is hydrogen and the other is one of the aforementioned groups, or R³⁴R³⁵ represents an adamantylidine group; and wherein at least one of R³⁰, R³¹, R³², R³⁵ and R³⁶ is the group L[(B)t](R)x.

[0140] The fulgides and fulgimides comprising polymeric substituent substituents in accordance with the invention may be particularly useful in molecular switches.

[0141] The fulgides and fulgimides of formula XXX may be formed in accordance with procedures similar to those described in US Patent 4,220,708. Fulgides of formula XXX(a) in which the group A- is oxygen may be prepared from five membered heterocycle of formula XXX by reaction with an ester of succinic acid of formula XXXII wherein R³⁷ is a residue of an alcohol, by a Stobbe condensation reaction. Hydrolysing the half ester product of XXXIII formed in the reaction provides the diacid of XXXIII wherein R³⁷ is hydrogen. Heating of the diacid of formula XXXIII yields the succinic anhydride product of formula XXXI 11 (a). The Stobbe condensation may be carried out by refluxing in t-butanol containing potassium t-butoxide or with sodium hydride in anhydrous toluene. Compounds of the invention of formula XXX(b) in which A- of formula XXX is N-36 may be prepared from the compound of XXX(a) by heating the anhydride and a primary amine R³⁶NH₂ to produce the corresponding half amide which can in turn be cyclised to form the imide of formula XXX(b) for example by heating with an acid chloride or acid anhydride. Alternatively the half ester Stobbe condensation product of formula XXX can be converted to the imide of XXX(b) by reaction with a compound of formula R³⁶NHMgBr to produce the corresponding succinamic acid which may be dehydrated with an acid chloride to provide the compound of formula XXX(b). Compounds of formula XXX(b).

wherein R comprises an polymeric substituent group are particularly preferred.

[0142] Compounds of formula XXXI wherein R³⁰ includes the polymeric substituent L[(B)t](R)x may be prepared by reaction of a polymeric substituent acid chloride such as (XXXV) with the appropriate furan in the presence of a Lewis acid catalyst (such as tin tetrachloride):

Fulgimide compounds of formula XXX in which

A' is the group of formula XXXVI may be prepared by reaction of an amine with a free nucleophilic group such as 4-hydroxyaniline with the corresponding fulgide of formula XXX where A' is oxygen to provide the intermediate fulgimide having a free nucleophilic group such as hydroxy (eg formula XXXVII) and reaction of the free nucleophilic of the fulgimide with (i) a polymeric substituent acid chloride or anhydride (ii) functional groups suitable to allow the growth of a polymer directly from the fulgimide. This might be a group suitable for RAFT, ATRP or iniferter control radical polymerization to provide the polymeric substituent substituted fulgimide of (eg formula XXXVI).

[0143] Examples of azo dyes include compounds of formula XL

wherein: one of R⁴⁰ and R⁴¹ is a polymeric substituent and the other is selected from the group consisting of hydrogen, C₁ to C₆ alkyl, C₁ to C₆ alkoxy, -NR⁴²R⁴³ wherein R⁴² and R⁴³ are as defined for R²⁶ and R²⁷ aryl (such as phenyl) aryl substituted with one or more substituents selected from C₁ to C₆ alkyl and C₁ to C₆ alkoxy, substituted C₁ to C₆ alkyl wherein the substituent is selected from aryl and C₁ to C₆ alkoxy, substituted C₁ to C₆ alkoxy wherein the substituent is selected from C₁ to C₆ alkoxy aryl and aryloxy. [0144] The photochromic moiety may also be selected from diarylperfluorocyclopentenes including compounds of formula XXXV and XXXVI:

wherein

R³⁴, R³⁵, R³⁶, R³⁷ independently represents a Ci to C₄ alkyl, phenyl or phen(Ci to

C₄) alkyl or one of and R³⁴ ,R³⁵ R³⁶, R³⁷ is hydrogen and the others is one of the aforementioned groups; and wherein at least one of Q , R³⁴, R³⁵ , R³⁶ and R³⁷comprises the groupL[(B)t](R)x.

Some non-limiting specific examples of compounds of the invention are included in Tables 1-3. Table 1

Table 2

Table 3

[0145] The compounds of the invention may contain one or more photochromic dyes. The compounds of the invention may also be used in mixtures with conventional photochromies.

[0146] The use of compounds of the invention allows the fatigue to be improved and preferably the fade speed of the photochromic to be changed without changing its colour. Thus it allows the tuning of fade speed for different coloured dyes. This is important to get a consistent colour when fading occurs. Thus, if a blue dye of a particular speed is needed, modification can be made to include an polymeric substituent of an appropriate length in accordance with the invention.

[0147] The photochromic compounds (or compositions containing same) of the present invention may be applied or incorporated into a host material by methods known in the art. Such methods include dissolving or dispersing the compound in the host material. The compound may be melt blended with the host matrix. [0148] The compounds of the invention may be incorporated in polymerizable compositions used to form the host matrix so that they become bound within the polymerized host. In one embodiment of the invention the photochromic compound of the invention comprises a group which is reactive with the polymerizable composition during curing. For example the polymerizable group may be an unsaturated group which becomes tethered to the host polymer during curing of the host composition. The group may be an alcohol, acid, amine or other group for reacting with co-reactive functional groups in a host monomer. In this embodiment the compound of the invention becomes chemically bound with the polymeric substituent forming a tether bound (particularly by covalent bonds) to the host. Reactions between the terminal group of the polymeric substituent of a photochromic compound are described in our co pending Australian provisional patent application No. 2004902302.

[0149] In one aspect the invention provides a photochromic article having a Tg of at least 50⁰C comprising a polymeric matrix formed by polymerization of a monomer composition comprising a photochromic monomer comprising a photochromic moiety which is tethered to a reactive group which has undergone reaction to become part of the polymer via a pendant polymeric substituent comprising polymeric group of low Tg comprising at least 3 and more preferably at least 5 and more preferably at least 7 monomeric units.

[0150] In the preferred embodiment the low Tg polymeric group provides a rate of fade of the photochromic which is significantly increased compared with the corresponding composition comprising an electrically equivalent dye without the low Tg polymeric group. Generally the photochromic article is solid at ambient temperature and typically it has a Tg of at least 50^QC, preferably at least 70^QC, and most preferably at least 8O⁰C.

[0151] The presence of low Tg substituent may simultaneously facilitate more rapid conversion between ring-open and ring-closed forms of the photochromic moiety. The polymeric substituent chains may provide a low Tg nanoenvironment or otherwise favourably alter the local environment. Accordingly for faster colouration and fade, it is preferred that the polymeric substituent attached to the photochromic compound of the invention has a relatively low Tg. For example the Tg is preferably less than 25⁰C. More preferably the compounds of the invention are non-crystalline at room temperature and more preferably liquid at room temperature, this making them easier to disperse and dissolve in the monomer composition.

[0152] Alternatively the compound of the invention may be reactive with the host and/or the polymerizable composition for forming the host. In this embodiment the compound of the invention may become incorporated in the host before, during or after curing of a polymerizable composition used to form the host.

[0153] The photochromic compound of the invention may be incorporated by imbibation into the host material. It may also be introduced by immersion, thermal transfer or coating and incorporation of the photochromic layer as part of a separation layer between adjacent layers of the host material. The term "imbibation" or "imbibe" is intended to mean and include diffusion of the photochromic compound alone into the host material, solvent assisted diffusion, absorption of the photochromic compound into a porous polymer, vapor phase transfer, and other such transfer mechanisms. For example:

(a) The photochromic compounds (or compositions containing same) of the present invention can be mixed with a polymerizable composition that, upon curing, produces an optically clear polymeric host material and the polymerizable composition can be cast as a film, sheet or lens, or injection molded or otherwise formed into a sheet or lens;

(b) The photochromic compounds of the present invention can be dissolved or dispersed in water, alcohol or other solvents or solvent mixtures and then imbibed into the solid host material by immersion for several minutes to several hours, eg, 2-3 minutes to 2-3 hours for the host material in a bath of such solution or dispersion. The bath is conventionally at an elevated temperature, usually in the range of 50O to 95 O. Thereafter, the host material is removed from the bath and dried;

(c) The photochromic compounds (and compositions containing the same) may also be applied to the surface of the host material by any convenient manner, such as spraying, brushing, spin-coating or dip-coating from a solution or dispersion of the photochromic material in the presence of a polymeric binder. Thereafter, the photochromic compound is imbibed by the host material by heating it, eg, in an oven, for from a minute to several hours at temperatures in the range of from 80O to 180O.;

(d) In a variation of the above imbibation procedure, the photochromic compound or composition containing the same can be deposited onto a temporary support, or fabric, which is then placed in contact with host material and heated, eg, in an oven;

(e) The photochromic compounds can be dissolved or dispersed in a transparent polymeric material which can be applied to the surface of the host in the form of a permanent adherent film or coating by any suitable technique such as spraying, brushing, spin-coating or dip-coating;

(f) The photochromic compounds can be incorporated or applied to a transparent polymeric material by any of the above mentioned methods, which can then be placed within the host material as a discrete layer intermediate to adjacent layers of a host material (s);

(g) The photochromic adduct of the invention may be incorporated into a dye composition by ball milling with a carrier to disperse it in a binder matrix. Such a composition may be used as an ink, for example in ink jet printing and suitable (PC) moieties may be chosen to allow security markings on documents to be visible on exposure to UV light used in photocopy;

(h) The photochromic compound may be compounded with suitable resins and the resin melted to shape it to form a film, for example by blow moulding or to form more complex extruded shapes, e.g. by injection moulding and/or blown structures.

[0154] The transfer method is described, inter alia, in the documents U.S. Pat. Nos. 4,286,957 and 4,880,667. In this technique, a surface of the transparent polymer substrate is coated with a layer of a varnish containing the photochromic substance to be incorporated. The substrate, thus coated, is then treated thermally in order to cause the photochromic substance to migrate into the substrate. [0155] Examples of host materials that may be used with the photochromic compounds of the present invention include polymers, i.e., homopolymers and copolymers of polyol(allyl carbonate) monomers, homopolymers and copolymers of polyfunctional acrylate monomers, polyacrylates, poly(alkylacrylates) such as poly(methylmethacrylate), cellulose acetate, cellulose triacetate, celluslose acetate propionate, cellulose acetate butyrate, polyvinyl acetate), poly(vinylalcohol), poly(vinylchloride), poly(vinlylidene chloride), polyurethanes, polycarbonates, poly(ethylene-terephthalate), polystyrene, copoly(styrene-methylmethacrylate), copoly(styrene-acrylateonitrile), poly(vinylbutryl), and homopolymers and copolymers of diacylidene pentaerythritol, particularly copolymers with polyol(allylcarbonate) monomers, e.g. diethylene glycol bis(allyl carbonate), and acrylate monomers. Transparent copolymers and blends of the transparent polymers are also suitable as host materials.

[0156] The host material may be an optically clear polymerized organic material prepared from a polycarbonate resin, such as the carbonate-linked resin derived from bisphenol A and phosgene which is sold under the trademark LEXAN; a poly(methylmethacrylate), such as the material sold under the trademark PLEXIGLAS; polymerizates of a polyol(allyl carbonate), especially diethylene glycol bis(allyl carbonate), which is sold under the trademark CR-39, and its copolymers such as copolymers with vinyl acetate, eg copolymers of from about 80 - 90 percent diethylene glycol bis(allyl carbonate) and 10 - 20 percent vinyl acetate, particularly 80 - 85 percent of the bis(allyl carbonate) and 15 - 20 percent vinyl acetate, cellulose acetate, cellulose propionate, cellulose butyrate, polystyrene and copolymers of styrene with methyl methacrylate, vinyl acetate and acrylonitrile, and cellulose acetate butyrate.

[0157] Polyol (allyl carbonate) monomers which can be polymerised to form a transparent host material are the allyl carbonates of linear or branched aliphatic glycol bis(allyl carbonate) compounds, or alkylidene bisphenol bis(allyl carbonate) compounds. These monomers can be described as unsaturated polycarbonates of polyols, eg glycols. The monomers can be prepared by procedures well known in the art, eg, US Pat. Nos. 2,370,567 and 2,403,113. The polyol (allyl carbonate) monomers can be represented by the graphic formula:

wherein R is the radical derived from an unsaturated alcohol and is commonly an allyl or substituted allyl group, R' is the radical derived from the polyol, and n is a whole number from 2-5, preferably 2. The allyl group (R) can be substituted at the 2 position with a halogen, most notably chlorine or bromine, or an alkyl group containing from 1 to 4 carbon atoms, generally a methyl or ethyl group. The R group can be represented by the graphic formula:

wherein R₀ is hydrogen, halogen, or a Ci-C₄ alkyl group. Specific examples of R include the groups: ally 2-chloroallyl, 2-bromoallyl, 2-fluoroallyl, 2-methylallyl, 2-ethylallyl, 2- isopropylallyl, 2-n-propylallyl, and 2-n-buylallyl. Most commonly R is the allyl group:

R' is the polyvalent radical derived from the polyol, which can be an aliphatic or aromatic polyol that contains 2, 3, 4 or 5 hydroxy groups. Typically, the polyol contains 2 hydroxy groups, ie a glycol or bisphenol. The aliphatic polyol can be linear or branched and contain from 2 to 10 carbon atoms. Commonly, the aliphatic polyol is an alkylene glycol having from 2 to 4 carbon atoms or a poly(C₂-C₄) alkylene glycol, ie ethylene glycol, propylene glycol, trimethylene glycol, tetramethylene glycol, or diethylene glycol, triethylene glycol etc.

[0158] In a further embodiment, the invention provides a photochromic article comprising a polymeric organic host material selected from the group consisting of poly(methyl methacrylate), polyethylene glycol bismethacrylate), poly(ethoxylated bisphenol A dimethacrylate), thermoplastic polycarbonate, polyvinyl acetate), polyvinylbutyral, polyurethane, and polymers of members of the group consisting of diethylene glycol bi(allylcarbonate) monomers, diethylene glycol dimethacrylate monomers, ethoxylated phenol bismethylacrylate monomers, diisopropenyl benzene monomers and ethoxylated trimethylol propane triacrylate monomers, and a photochromic amount of a compound of the invention.

[0159] The polymeric organic host material is selected from the group consisting of polyacrylates, polymethacrylates, poly(Ci-Ci₂) alkyl methacrylates, polyoxy(alkylene methacrylates), poly(alkoxylates phenol methacrylates), cellulose acetates, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, polyvinyl acetate), polyvinyl alcohol), polyvinyl chloride) poly(vinylidene chloride), thermoplastic polycarbonates, polyesters, polyurethanes, polythiourethanes, poly(ethylene terephthalate), polystyrene, poly(alpha methylstyrene), copoly(styrene- methylmethacrylate), copoly(styrene-acrylonitrile), polyvinylbutyral and polymers of members of the group consisting of polyol(allyl carbonate) monomers, polyfunctional acrylate monomers, polyfunctional methylacrylate monomers, diethylene glycol dimethacrylate monomers, diisopropenyl benzene monomers, alkoxylates polyhydric alcohol monomers and diallylidene pentaerythritol monomers.

[0160] The photochromic article may comprise a polymeric organic material which is a homopolymer or copolymer of monomer(s) selected from the group consisting of acrylates, methacrylates, methyl mathacrylate, ethylene glycol bis methacrylate, ethoxylated bisphenol A dimethacrylate, vinyl acetate, vinylbutyral, urethane, thiourethane, diethylene glycol bis(allyl carbonate), diethylene glycol dimethacrylate, diisopropenyl benzene, and ethoxylated trimethyl propane triacrylates.

[0161] The photochromic composition of the invention may contain the photochromic compound in a wide range of concentrations depending on the type of photochromic moiety and its intended application. For example in the case of inks in which high colour intensity is required a relatively high concentration of up to 30 wt% photochromic may be required. On the other hand it may be desirable in some cases such as optical articles to use photochromies in very low concentrations to provide a relatively slight change in optical transparency on irradiation. For example, as low as 0.01 mg/g of host resin may be used. Generally the photochromic resin will be present in an amount of from 0.001 wt% of host resin up to 30 wt% of host resin. More preferably the photochromic compound will be present in an amount of from 0.001 to 10 wt% of host matrix and still more preferably from 0.005 to 10 wt% of host matrix.

[0162] The photochromic article may contain the photochromic compound in an amount of from 0.05 to 10.0 milligram per square centimetre of polymeric organic host material surface to which the photochromic substance(s) is incorporated or applied.

[0163] The compounds of the invention may be used in those applications in which the organic photochromic substances may be employed, such as optical lenses, eg, vision correcting ophthalmic lenses and piano lenses, face shields, goggles, visors, camera lenses, windows, mirrors, automotive windows, jewellery, aircraft and automotive transparencies, e.g., T-roofs, sidelights and backlights, plastic films and sheets, textiles and coatings, e.g. coating compositions and inks, cosmetics, data storage devices, optical switching devices. As used herein, coating compositions include polymeric coating composition prepared from materials such as polyurethanes, epoxy resins and other resins used to produce synthetic polymers; paints, i.e., a pigmented liquid or paste used for the decoration, protection and/or the identification of a substrate; and inks, i.e., a pigmented liquid or paste used for writing and printing on substrates, which include paper, glass, ceramics, wood, masonry, textiles, metals and polymeric organic materials. Coating compositions may be used to produce verification marks on security documents, e.g. documents such as banknotes, passport and driver' licenses, for which authentication or verification of authenticity may be desired. Security documents, for indicating exposure to light during photocopying.

[0164] The invention will now be described with reference to the following examples. It is to be understood that the examples are provided by way of illustration of the invention and that they are in no way limiting to the scope of the invention. [0165] Examples of host materials that may be used with the photochromic compounds of the present invention include polymers, i.e., homopolymers and copolymers of polyol(allyl carbonate) monomers, homopolymers and copolymers of polyfunctional acrylate monomers, polyacrylates, poly(alkylacrylates) such as poly(methylmethacrylate), cellulose acetate, cellulose triacetate, celluslose acetate propionate, cellulose acetate butyrate, polyvinyl acetate), poly(vinylalcohol), poly(vinylchloride), poly(vinlylidene chloride), polyurethanes, polycarbonates, poly(ethylene-terephthalate), polystyrene, copoly(styrene-methylmethacrylate), copoly(styrene-acrylateonitrile), poly(vinylbutryl), and homopolymers and copolymers of diacylidene pentaerythritol, particularly copolymers with polyol(allylcarbonate) monomers, e.g. diethylene glycol bis(allyl carbonate), and acrylate monomers. Transparent copolymers and blends of the transparent polymers are also suitable as host materials.

[0166] The host material may be an optically clear polymerized organic material prepared from a polycarbonate resin, such as the carbonate-linked resin derived from bisphenol A and phosgene which is sold under the trademark LEXAN; a poly(methylmethacrylate), such as the material sold under the trademark PLEXIGLAS; polymerizates of a polyol(allyl carbonate), especially diethylene glycol bis(allyl carbonate), which is sold under the trademark CR-39, and its copolymers such as copolymers with vinyl acetate, eg copolymers of from about 80 - 90 percent diethylene glycol bis(allyl carbonate) and 10 - 20 percent vinyl acetate, particularly 80 - 85 percent of the bis(allyl carbonate) and 15 - 20 percent vinyl acetate, cellulose acetate, cellulose propionate, cellulose butyrate, polystyrene and copolymers of styrene with methyl methacrylate, vinyl acetate and acrylonitrile, and cellulose acetate butyrate.

[0167] Polyol (allyl carbonate) monomers which can be polymerised to form a transparent host material are the allyl carbonates of linear or branched aliphatic glycol bis(allyl carbonate) compounds, or alkylidene bisphenol bis(allyl carbonate) compounds. These monomers can be described as unsaturated polycarbonates of polyols, eg glycols. The monomers can be prepared by procedures well known in the art, eg, US Pat. Nos. 2,370,567 and 2,403,113. The polyol (allyl carbonate) monomers can be represented by the graphic formula:

[0168] In a further embodiment, the invention provides a photochromic article comprising a polymeric organic host material selected from the group consisting of poly(methyl methacrylate), polyethylene glycol bismethacrylate), poly(ethoxylated bisphenol A dimethacrylate), thermoplastic polycarbonate, polyvinyl acetate), polyvinylbutyral, polyurethane, and polymers of members of the group consisting of diethylene glycol bi(allylcarbonate) monomers, diethylene glycol dimethacrylate monomers, ethoxylated phenol bismethylacrylate monomers, diisopropenyl benzene monomers and ethoxylated trimethylol propane triacrylate monomers, and a photochromic amount of a compound of the invention.

[0169] The polymeric organic host material is selected from the group consisting of polyacrylates, polymethacrylates, poly(Ci-Ci₂) alkyl methacrylates, polyoxy(alkylene methacrylates), poly(alkoxylates phenol methacrylates), cellulose acetates, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, polyvinyl acetate), polyvinyl alcohol), polyvinyl chloride) poly(vinylidene chloride), thermoplastic polycarbonates, polyesters, polyurethanes, polythiourethanes, poly(ethylene terephthalate), polystyrene, poly(alpha methylstyrene), copoly(styrene- methylmethacrylate), copoly(styrene-acrylonitrile), polyvinylbutyral and polymers of members of the group consisting of polyol(allyl carbonate) monomers, polyfunctional acrylate monomers, polyfunctional methylacrylate monomers, diethylene glycol dimethacrylate monomers, diisopropenyl benzene monomers, alkoxylates polyhydric alcohol monomers and diallylidene pentaerythritol monomers.

[0170] The photochromic article may comprise a polymeric organic material which is a homopolymer or copolymer of monomer(s) selected from the group consisting of acrylates, methacrylates, methyl mathacrylate, ethylene glycol bis methacrylate, ethoxylated bisphenol A dimethacrylate, vinyl acetate, vinylbutyral, urethane, thiourethane, diethylene glycol bis(allyl carbonate), diethylene glycol dimethacrylate, diisopropenyl benzene, and ethoxylated trimethyl propane triacrylates.

[0171] The photochromic composition of the invention may contain the photochromic compound in a wide range of concentrations depending on the type of photochromic moiety and its intended application. For example in the case of inks in which high colour intensity is required a relatively high concentration of up to 30 wt% photochromic may be required. On the other hand it may be desirable in some cases such as optical articles to use photochromies in very low concentrations to provide a relatively slight change in optical transparency on irradiation. For example, as low as 0.01 mg/g of host resin may be used. Generally the photochromic resin will be present in an amount of from 0.001 wt% of host resin up to 30 wt% of host resin. More preferably the photochromic compound will be present in an amount of from 0.001 to 10 wt% of host matrix and still more preferably from 0.005 to 10 wt% of host matrix.

[0172] The photochromic article may contain the photochromic compound in an amount of from 0.05 to 10.0 milligram per square centimetre of polymeric organic host material surface to which the photochromic substance(s) is incorporated or applied.

[0173] The compounds of the invention may be used in those applications in which the organic photochromic substances may be employed, such as optical lenses, e.g., vision correcting ophthalmic lenses and piano lenses, face shields, goggles, visors, camera lenses, windows, mirrors, automotive windows, jewellery, aircraft and automotive transparencies, e.g., T-roofs, sidelights and backlights, plastic films and sheets, textiles and coatings, e.g. coating compositions and inks, cosmetics, data storage devices, optical switching devices. As used herein, coating compositions include polymeric coating composition prepared from materials such as polyurethanes, epoxy resins and other resins used to produce synthetic polymers; paints, i.e., a pigmented liquid or paste used for the decoration, protection and/or the identification of a substrate; and inks, i.e., a pigmented liquid or paste used for writing and printing on substrates, which include paper, glass, ceramics, wood, masonry, textiles, metals and polymeric organic materials. Coating compositions may be used to produce verification marks on security documents, e.g. documents such as banknotes, passport and driver' licenses, for which authentication or verification of authenticity may be desired. Security documents, for indicating exposure to light during photocopying.

[0174] The invention will now be described with reference to the following examples. It is to be understood that the examples are provided by way of illustration of the invention and that they are in no way limiting to the scope of the invention. Examples

EXAMPLE 1

Spiropyran hetero V '-branched (poly(dimethylsiloxane)/ATRP initiator) conjugate

Step i

[0175] Mono-hydroxy end-terminated poly(dimethylsiloxane), 1 , (Gelest, Inc.) (25 g, ca.

0.0221 mol) and succinic anhydride (2.65 g, 0.0265 mol) were added to dry CH₂CI₂ (ca. 30 ml_) under nitrogen. Triethylamine (3.35 g, 4.6 ml_, 0.0331 mol) was then added in one portion and the mixture was stirred at room temperature for 30 minutes followed by heating at 35O for 1 hour. Polyethylene glycol met hyl ether (3.86 g, 0.0110 mol) was then added and the mixture stirred for an additional 30 minutes at 35O. It was then poured into hexane, washed with several portions of 2M HCI, the organic layer dried with MgSO₄ and the solvent evaporated to give the pure product, 2, as a colourless oil (26.34 g, 97 %).

[0176] Comments: an excess of succinic anhydride is used to drive the reaction to completion. The removal of the remaining anhydride is facilitated by its reaction with PEG methyl ether, resulting in a very polar product which is easily extracted with water. This procedure gives a very pure product in high yield without the need for further purification. ¹H NMR (400 MHz, CDCI₃) δ 4.25 (t, J = 4.76 Hz, 2H, CH₂-3), 3.63 (t, J = 4.76 Hz, 2H, CH₂-4), 3.42 (t, J = 7.32 Hz, 2H, CH₂-5), 2.67 (s, 4H, CH₂-1 , 2), 1.61 (m, 2H, CH₂-6), 1.31 (m, 4H, CH₂-9,10), 0.88 (t, J = 6.95 Hz, 3H, CH₃-H ), 0.53 (m, 4H, CH₂-7,8), 0.07 (s, approx. 8OH, SiCH₃).

Step 2

[0177] Compound 2 (Ex. 1 , Step 1) (1.0 g, ca. 0.811 mmol) was dissolved in dry CH₂CI₂ (10 ml_) under argon and 1 drop DMF added. The mixture was cooled in an ice bath and then oxalyl chloride (0.41 g, 0.28 ml_, 3.244 mmol) added in one portion. Stirring was continued at OO for 15 minutes and then at room te mperature for 20 minutes whilst maintaining a slow argon flow above the reaction by means of a syringe needle through a rubber septum. The solvent and excess reagent was removed by evaporation in vacuo and the residual reagent further removed in vacuo with the aid of 1 ,2-dichloroethane. The acid chloride product, 3, was used immediately. Analysis by ¹H NMR in d-chloroform showed quantitative conversion.

[0178] Comments: it is important that the reaction duration be no longer than 30 minutes at room temperature. Significant amounts of by-products are formed at longer reaction times and when more forcing conditions are used (Ae. elevated temperatures). It is believed that the HCI formed during the reaction cleaves the ether linkage and also attacks the PDMS chain. An argon flow above the vigorously stirred reaction mixture may assist in the removal of gaseous HCI as it is formed. ¹H NMR (400 MHz, CDCI₃) δ 4.26 (t, J = 4.76 Hz, 2H, CH₂-3), 3.63 (t, J = 4.76 Hz, 2H, CH₂-4), 3.42 (t, J = 6.95 Hz, 2H, CHz-5), 3.22 (t, J = 6.59 Hz, 2H, CH₂-I ), 2.72 (t, J = 6.59 Hz, 2H, CH₂-2), 1.61 (m, 2H, CH₂-6), 1.31 (m, 4H, CH₂-9,10), 0.88 (t, J = 6.95 Hz, 3H, CH₃-H ), 0.53 (m, 4H, CH₂- 7,8), 0.07 (s, approx. 8OH, SiCH₃).

Step 3

[0179] To a solution of dried (2 hrs at 130O under vacuum ) 2,2- bis(hydroxymethyl)propionic acid (10.1 1 g, 75.4 mmol) in dry dichloromethane was added triethylamine (8.53 g, 84.3 mmol) under nitrogen. Compound 3 (Ex. 1 , Step 2) (10.14 g, 7.54 mmol, average mol. wt. = 1 ,345) was then added dropwise to the cooled solution and then stirred at room temperature for 30 minutes. The solvent was then evaporated in vacuo and the residue re-dissolved in diethyl ether, washed 4 times with dilute aq. HCI, then brine and dried with MgSO₄. The solvent was evaporated and the crude product purified by column chromatography (silica gel, diethyl ether/hexane, 1 :1 → 4:1 → neat ether).

[0180] Comments: Fractionation is achieved on the column due to the distribution of PDMS chain lengths. The product elutes from the column as a broad band with longer PDMS chain lengths eluting first. Average molecular weights of the pure product fractions collected were therefore determined by ¹H NMR (integration of PDMS CH₃'s versus end-functionality). The syntheses which follow use various fractions of product compound 4 with differing molecular weights. ¹H NMR (400 MHz, CDCI₃) δ 4.33-4.23 (m, 4H), 3.67 (m, 4H), 3.47 (t, 2H), 2.65 (s, 4H), 1.63 (m, 2H), 1.31 (m, 4H), 1.22 (s, 3H), 0.87 (t, 3H), 0.53 (m, 4H), 0.06 (m, SiCH₃).

Step 4

[0181] Compound 4 (Ex. 1 , Step 3) (0.70 g, 0.56 mmol, average mol. wt. = 1 ,250) was dissolved in dry dichloromethane (10 ml_) under nitrogen, then triethylamine (0.142 g, 1.40 mmol) added. 2-Bromopropionyl bromide (0.133 g, 0.62 mmol) was added via syringe and the mixture stirred for 40 minutes at room temperature. DMAP (10 mg) was then added and the mixture stirred for another 1 hour. The solvent was evaporated and the residue added to diethyl ether, then washed with dilute aq. HCI, dried with MgSO₄ and solvent evaporated. This gave the product, 5, (0.745 g) of sufficient purity for use in the next step, with an average molecular weight of 1 ,401 as determined by ¹H NMR. ¹ H NMR (400 MHz, CDCI₃) δ 4.40-4.20 (m, 7H), 3.71 (m, 2H), 3.50 (m, 2H), 2.65 (m, 4H), 1.82 (d, 3H), 1.64 (m, 2H), 1.30 (m, 7H), 0.88 (t, 3H), 0.53 (m, 4H), 0.06 (m, SiCH₃). Step 5

[0182] Compound 5 (Ex. 1 , Step 4) (0.71 g, 0.507 mmol) was dissolved in dry dichloromethane ( 10 ml_) under nitrogen with 1 drop of DMF. Oxalyl chloride (0.19 g, 1.52 mmol) was added in one portion and the mixture stirred for 30 minutes at room temperature after which the solvent and excess reagent were evaporated in vacuo. The acid chloride product was used immediately for the next step.

Step 6

[Hydroxyethyl-functionalised spiropyran, 2-(3',3'-dimethyl-6-nitro-3'/-/-spiro[chromene- 2,2'-indol]-1 '-yl)-ethanol, was synthesised according to the literature procedure: F. M. Raymo and S. Giordani, J. Am. Chem. Soc, 2001 , 123, 4651 -4652].

[0183] The hydroxymethyl-functionalised spiropyran (0.179 g, 0.507 mmol) was dissolved in dry dichloromethane (20 ml_) under nitrogen together with triethylamine (0.154 g, 1.52 mmol). The acid chloride product (Ex. 1 , Step 5), dissolved in dry dichloromethane (6 ml_), was added dropwise followed by the addition of DMAP (10 mg). The solution stirred at room temperature for 2 hours, the solvent then evaporated in vacuo and the residue purified by column chromatography (silica gel, diethyl ether/hexane, 1 :2). This gave the pure product, Example 1 , (0.204 g) with an average molecular weight of 1 ,794 as determined by ¹H NMR. ¹H NMR (400 MHz, d₆-acetone) δ 8.14 (d, 1 H), 8.05 (m, 1 H), 7.24-7.15 (m, 3H), 6.86 (m, 2H), 6.79 (d, 1 H), 6.12 (d, 1 H), 4.50 (m, 1 H), 4.35-4.24 (m, 6H), 4.16 (t, 2H), 3.59 (m, 3H), 3.52 (m, 1 H), 3.41 (t, 2H), 2.56 (s, 4H), 1.72 (d, 3H), 1.61 (m, 2H), 1.35 (m, 4H), 1.29 (s, 3H), 1.23 (s, 3H), 1.19 (s, 3H), 0.89 (m, 3H), 0.59 (m, 4H), 0.11 (m, SiCH₃). EXAMPLE 2

Naphthopyran hetero V '-branched (poly(dimethylsiloxane)/dodecenyl) conjugate

Step i

[0184] Triethylamine (1.84 ml_, 13.2 mmol) was added in one portion to a stirred solution of mono-hydroxy end-terminated poly(dimethylsiloxane), 1 , (10.0 g, ca. 8.8 mmol) and 2-dodecen-1-ylsuccinic anhydride (2.35 g, 8.8 mmol) in CH₂CI₂ {ca. 20 ml_) under nitrogen. The mixture was stirred at room temperature for 45 minutes followed by heating at 40O for 2.5 hours and stirring at room temperat ure overnight. The mixture was poured into petroleum spirit (40-60⁰C, 100 ml_) and washed with 2M HCI (60 ml_). The organic phase was dried with MgSO₄ and the solvent evaporated to give the products 6a+6b (2.96 g, 96 %) as a very pale yellow oil, which was used without further purification.

[0185] Comment: The regioisomeric products result from ring opening at each of the carbonyl groups of the anhydride moiety.

¹H NMR (400 MHz, CD₃COCD₃) δ 5.57-5.46 (m, 1 H), 5.45-5.34 (m, 1 H), 4.27-4.10 (m, 2H), 3.60 (m, 2H), 3.42 (m, 2H), 2.70-2.60 (m, 1 H), 2.50-2.23 (m, 6H), 2.00 (m, 2H), 1.61 (m, 2H), 1.35 (m, 4H), 1.29 (m, 12H), 0.89 (t, J = 7 Hz, 3H), 0.88 (t, J = 7 Hz, 3H), 0.63- 0.55 (m, 4H), 0.14-0.08 (m, approx. 80H). Step 2

[0186] The crude compound 6a/6b (Ex. 2, Step 1 ) (0.79 g, ca. 0.565 mmol) was dissolved in dry CH₂CI₂ (7 ml_) under argon and DMF (1 drop) added. Oxalyl chloride (0.19 ml_, 2.26 mmol) was added slowly. Stirring was continued at room temperature for 40 minutes whilst maintaining a slow nitrogen flow above the reaction by means of a syringe needle through a rubber septum. The solvent and a majority of excess reagent was removed by evaporation in vacuo and the residual reagent removed in vacuo with the aid of 1 ,2-dichloroethane. The acid chloride product was immediately dissolved in CH₂CI₂ (2 ml_) and added dropwise to a stirred solution of 2,2-£>/s(4-methoxyphenyl)-5- methylcarboxylate-6-hydroxy-2/-/-naphtho[1 ,2-£>]pyran (0.264 g, 0.565 mmol) and triethylamine (0.16 ml_, 1.13 mmol) in CH₂CI₂ (5 ml_) under a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 7.5 hours. The solvent was evaporated in vacuo and the residue, after being stored in a refrigerator at 4°C overnight, was re-dissolved in CH₂CI₂ and this solution filtered through a plug of cotton wool. The filtrate was purified by flash column chromatography (SiO₂, 33-100% CH₂CI₂ in petroleum spirit (40-60⁰C)) to give the product, Example 2, (0.326 g, 31 %) as a viscous pink/red -coloured gum. ¹H NMR (400 MHz, de-acetone) δ 8.40 (d, J = 8.1 Hz, 1 H), 7.95 (d, J = 8.4 Hz) and 7.88 (d, J = 8.4 Hz) (1 H), 7.66 (m, 1 H), 7.59 (m, 1 H), 7.44 (d, J = 8.5 Hz, 4H), 6.95 (d, J = 10 Hz, 1 H), 6.87 (d, J = 8.5 Hz, 4H), 6.40 (m, 1 H), 5.70-5.40 (m, 2H), 4.32-4.14 (m, 2H), 3.94 (s, 3H), 3.75 (s, 6H), 3.62 (t, J = 5 Hz, 2H), 3.41 (m, 2H), 3.15-2.35 (m, partly obscured by solvent signals), 2.08 (m, partly obscured by solvent signals), 1.59 (m, 2H), 1.34 (m, 4H), 1.28 (m, 12H), 0.87 (m, 6H), 0.58 (m, 4H), 0.13-0.07 (m). EXAMPLE 3

Spirooxazine hetero Y-branched (poly(dimethylsiloxane)/dodecenyl) conjugate

[0187] The crude compound 6a/6b (Ex. 2, Step 1 ) (1.91 g, ca. 1.36 mmol) was dissolved in dry CH₂CI₂ (10 ml_) under argon and DMF (2 drops) added. Oxalyl chloride (0.58 ml_, 6.8 mmol) was added slowly. Stirring was continued at room temperature for 30 minutes whilst maintaining a slow nitrogen flow above the reaction by means of a syringe needle through a rubber septum. The solvent and a majority of excess reagent was removed by evaporation in vacuo and the residual reagent removed in vacuo with the aid of 1 ,2- dichloroethane. The acid chloride product was immediately dissolved in CH₂CI₂ (7 ml_) and added dropwise to a stirred solution of 9'-hydroxy-1 ,3,3-trimethylspiro[indoline-2,3'- [3H]naphtha[2,1-b][1 ,4]oxazine (0.468 g, 1.36 mmol) and triethylamine (0.38 m|_, 2.72 mmol) in CH₂CI₂ (8 ml_) under a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 19 hours. The solvent was evaporated in vacuo and the residue was re-dissolved in CH₂CI₂ and this solution filtered through a plug of cotton wool. The filtrate was purified by flash column chromatography (SiO₂, CH₂CI₂/petroleum spirit (40-60⁰C), 1 :1 →2:1 , then 0-5% ethyl acetate in CH₂CI₂) to give the product, Example 3, (1.47 g, 63%) as a viscous golden honey-coloured gum. ¹H NMR (400 MHz, de-acetone) δ 8.24 (s, 1 H), 7.87 (d, J = 8.7 Hz, 1 H), 7.83-7.78 (m, 2H), 7.22-7.12 (m, 3H), 7.03 (d, J = 8.8 Hz, 1 H), 6.86 (t, J = 7.3 Hz, 1 H), 6.65 (d, J = 7.7 Hz, 1 H), 5.71 -5.41 (m, 2H), 4.32-4.18 (m, 2H), 3.66 (m, 2H), 3.44 (m, 2H), 3.15-2.35 (m, partly obscured by solvent signals), 2.76 (s, 3H), 2.09 (m, partly obscured by solvent signals), 1.61 (m, 2H), 1.48-1.20 (m, 16H), 1.36 (s, 3H), 1.34 (s, 3H), 0.87 (m, 6H), 0.58 (m, 4H), 0.14-0.06 (m). EXAMPLE 4 (including COMPARATIVE EXAMPLE 1)

Spirooxazine hetero Y-branched (poly(dimethylsiloxane)/methacrylate) conjugate

[0188] Methacryloyl chloride (0.16 ml_, 1.65 mmol) was added dropwise to a stirred solution of compound 4 (Ex. 1 , Step 3) (1.18 g, 0.75 mmol), triethylamine (0.31 ml_, 2.25 mmol) and 4-dimethylaminopyridine (1-2 mg) in CH₂CI₂ (8 ml_) under a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 5 hours and then partitioned between CH₂CI₂ and dilute hydrochloric acid (2 M). The organic phase was washed with brine, dried (MgSO₄) and the solvent evaporated in vacuo. The residual crude compound 7 (1.16g, 0.705 mmol) was re-dissolved in CH₂CI₂ (7 ml_) and sealed under an atmosphere of nitrogen with a rubber septum. DMF (2 drops) was injected, followed by the dropwise addition of oxalyl chloride (0.30 ml_, 3.5 mmol). The resulting solution was stirred at room temperature for 35 minutes whilst maintaining a slow nitrogen flow above the reaction by means of a syringe needle through the rubber septum. The solvent and a majority of excess reagent was removed by evaporation in vacuo and the residual reagent removed in vacuo with the aid of 1 ,2-dichloroethane. The crude acid chloride product was immediately dissolved in CH₂CI₂ (4 ml_) and added dropwise to a stirred solution of 9'-hydroxy-1 ,3,3-trimethylspiro[indoline-2,3'- [3H]naphtha[2,1-b][1 ,4]oxazine (0.241 g, 0.70 mmol) and triethylamine (0.20 ml_, 1.40 mmol) in CH₂CI₂ (5 ml_) under a nitrogen atmosphere. The resulting mixture was stirred at room temperature for 21.5 hours. The solvent was evaporated in vacuo and the residue was re-dissolved in CH₂CI₂ and this solution filtered through a plug of cotton wool. The filtrate was purified by flash column chromatography over silica gel. Elution with 50-100% CH₂CI₂ in petroleum spirit (40-60⁰C) afforded the side product 1,3,3- trimethylspiro[indoline-2,3'-naphtho[2,1-b][1 ,4]oxazine]-9'-yl methacrylate, Comparative Example 1, (0.171 g, 59%).¹H NMR (400 MHz, de-acetone) δ 8.28 (d, J = 2.4 Hz, 1H), 7.90 (d, J = 8.8 Hz, 1 H), 7.82 (s, 1 H), 7.82 (d, J = 8.9 Hz, 1 H), 7.25 (d, J = 2.4 Hz, 1 H), 7.23 (d, J = 2.4Hz, 1H), 7.18 (dd, J = 7.7, 1.2 Hz, 1H), 7.14 (dd, J= 7.2, 0.8 Hz, 1H), 7.04 (d, J= 8.9 Hz, 1H), 6.86 (dt, J= 7.4, 0.8 Hz, 1H), 6.65 (d, J= 7.8 Hz, 1H), 6.38 (m, 1H), 5.88 (m, 1H), 2.77 (s, 3H), 2.09 (m, 3H), 1.35 (s, 3H), 1.33 (s, 3H).

[0189] Further elution with 2-5% ethyl acetate in CH₂CI₂ gave the desired product compound, Example 4, (0.313 g, 23%) as a viscous golden honey-coloured oil. ¹H NMR (400 MHz, de-acetone) δ 8.24 (d, J= 2.4 Hz, 1H), 7.89 (d, J= 8.8 Hz, 1H), 7.83 (s, 1H), 7.81 (d, J= 8.9Hz, 1H), 7.21-7.13 (m, 3H), 7.05 (d, J= 8.9 Hz, 1H), 6.86 (dt, J= 7.4, 0.7 Hz, 1H), 6.65 (d, J= 7.7 Hz, 1H), 6.17 (m, 1H), 5.71 (m, 1H), 4.53 (s, 2H), 4.52 (s, 2H), 4.18 (m, 2H), 3.59 (m, 2H), 3.40 (t, J= 6.8 Hz, 2H), 2.77 (s, 3H), 2.77-2.67 (m, 4H), 1.98 (m, 3H), 1.60 (m, 2H), 1.54 (s, 3H), 1.38-1.32 (m, 4H), 1.36 (s, 3H), 1.33 (s, 3H), 0.89 (m, 3H), 0.61-0.55 (m, 4H), 0.13-0.07 (m).

EXAMPLE 5

Spiropyran hetero Y-branched (poly(dimethylsiloxane)/hindered phenol) conjugate

[0190] Compound 4 (Ex. 1 , Step 3) (0.415 g, 0.356 mmol, average mol. wt. = 1 ,166) was dissolved in dry dichloromethane (10 ml_) under nitrogen, then triethylamine (0.144 g, 1.42 mmol) and DMAP (10 mg) added. 3-(3,5-Di-te/t-butyl-4-hydroxyphenyl)propionyl chloride (0.132 g, 0.445 mmol) was added as a solid and the mixture stirred for 50 minutes at room temperature. The solvent was evaporated and the residue added to diethyl ether, then washed with dilute aq. HCI, dried with MgSO₄ and then filtered through a plug of silica gel. The solvent was evaporated giving crude compound, 8, containing ca. 25 mol% of 3-(3,5-di-terf-butyl-4-hydroxyphenyl)propionic acid (as determined by ¹H NMR). The crude residue was dissolved in dry dichloromethane (10 ml_) with 1 drop of DMF then oxalyl chloride (0.23 g, 1.78 mmol) added in one portion. The mixture was stirred for 35 minutes at room temperature under nitrogen, the solvent and excess reagent then evaporated in vacuo. The acid chloride product was use immediately for the next step.

[0191] The hydroxyethyl-functionalised spiropyran (0.173 g, 0.491 mmol) was dissolved in dry dichloromethane (10 ml_) under nitrogen together with triethylamine (0.10 g, 0.98 mmol). The acid chloride product from step 1 , dissolved in dry dichloromethane (5 ml_), was added in one portion followed by the addition of DMAP (10 mg). The solution was stirred at room temperature for 30 minutes and the solvent then evaporated in vacuo. The residue was re-dissolved in diethyl ether, washed with dilute aqueous HCI, then brine and dried with MgSO₄. The solution was filtered through a small plug of silica gel and the solvent evaporated. The crude product was then purified by column chromatography (silica gel, diethyl ether/hexane, 1 :1 → 2:1 ). This gave the pure product, Example 5, (0.157 g) with an average molecular weight of 1 ,664 (determined by ¹ H NMR). ¹H NMR (400 MHz, de-acetone) 6 8.13 (d, 1 H), 8.03 (dd, 1 H), 7.22-7.11 (m, 3H), 6.99 (s, 2H), 6.86-6.77 (m, 3H), 6.11 (d, 1 H), 5.83 (s, 1 H), 4.34-4.24 (m, 2H), 4.19 (br s, 4H, slight overlap), 4.15 (t, 2H, slight overlap), 3.58 (m, 3H), 3.51 -3.44 (m, 1 H, slight overlap), 3.41 (t, 2H, slight overlap), 2.76 (m, 2H, overlap with H₂O signal), 2.54 (m, 6H), 1.60 (m, 2H), [1.40 (s, overlap) plus 1.35 (m, overlap), 22H], 1.28 (s, 3H), 1.17 (s, 3H), 1.13 (s, 3H), 0.89 (m, 3H), 0.58 (m, 4H), 0.12-0.08 (m, SiCH₃).

EXAMPLE 6

Spiropyran hetero Y-branched (poly(dimethylsiloxane)/poly(butyl acrylate-co-hindered amine acrylate)) conjugate

[0192] (BA)₅-DETA, ligand used for Atom Transfer Radical Polymerisation (ATRP), was synthesised according to the procedure of Chu et al. J. Polym. Sci.: Part A: Polym. Chem. 2004, 42, 1963-1969, using butyl acrylate in place of methyl acrylate.

[0193] The spiropyran macroinitiator, Example 1 , (0.080 g, 5.25 x 10 v5 mol), π-butyl acrylate (0.5383 g, 4.2 x 10^"3 mol), 4-(acryloyloxy)-1 ,2,2,6,6-pentamethylpiperidine (0.2366 g, 1.05 x 10^"3 mol), copper(l) bromide (0.0075 g, 5.25 x 10^"5 mol) and (BA)₅- DETA (0.0781 g, 1.05 x 10^"4 mol) were combined in an ampoule together with anisole (1.5 ml_) as solvent. The mixture was degassed with 4 freeze/pump/thaw cycles under high vacuum, sealed and then heated at 8OO in a th ermostat controlled constant temperature oil bath for 20.5 hours. Analysis by ¹H NMR (d₆-acetone) gave a conversion of 71 % for both monomers. Excess monomers were partially evaporated by dissolving bulk mixture in chloroform and passing a stream of nitrogen over the solution. The residue was then twice precipitated by addition of methanol to a concentrated solution of the residue in chloroform, followed by slow and partial evaporation of the solvent to approx. VA of the initial volume, followed by decantation of the supernatant. Removal of trace amounts of copper catalyst was then effected by passing the residue through a short plug of silica gel, eluting with diethyl ether. Analysis by ¹H NMR (αfe-acetone) gave a calculated average molecular weight of 13,641.

EXAMPLE 7

Spiropyran hetero Y-branched (poly(dimethylsiloxane)/poly(allyl methacrylate-co-methyl methacrylate)) conjugate

[0194] Two ampoules were charged with spiropyran macroinitiator, Example 1 , (0.10 g,

5.57 x 10^"5 mol), allyl methacrylate (0.7027 g, 5.57 x 10^"3 mol), methyl methacrylate (0.5577 g, 5.57 x 10^"3 mol), copper(l) chloride (0.0055 g, 5.57 x 10^"5 mol), (BA)₅-DETA (0.0497 g, 6.68 x 10^"5 mol) and acetone (4 ml_). The mixtures were degassed with 4 freeze/pump/thaw cycles under high vacuum and the ampoules sealed. The ampoules were heated in a thermostat controlled constant temperature oil bath. Ampoule 1 was heated at 60O for 1 hour. Ampoule 2 was heated at 60O for 1 hour, then at 7OO for 30 minutes and finally at 80O for 20 minutes. Excess monomers were partially evaporated by dissolving bulk mixture in chloroform and passing a stream of nitrogen over the solution. Removal of trace amounts of copper catalyst was then effected by passing the residue through a short plug of silica gel, eluting with diethyl ether. Analysis by ¹H NMR (de-acetone) gave calculated average molecular weights of 3,617 (ampoule 1 ) and 4,879 (ampoule 2). EXAMPLE 8

Naphthopyran hetero Y-branched (poly(dimethylsiloxane)/p-methoxycinnamate UV absorber) conjugate

Step 1

[0195] 4-Methoxycinnamic acid (0.705 g, 3.96 mmol) was dissolved in dry THF (15 ml) in a dry Schlenk flask under nitrogen. DMF (one drop) was added via syringe followed by oxalyl chloride (0.415 ml, 4.75 mmol) in one portion. The mixture was stirred at room temperature for 30 minutes. The solvent and excess oxalyl chloride was removed by evaporation in vacuo. Residual reagent was removed by a second evaporation in vacuo with the aid of dichloromethane. The product, 4-methoxycinnamoyl chloride, was obtained as a light yellow oil in quantitative yield and was used immediately in the next step.

Step 2

[0196] Mono(dicarbinol) terminated PDMS (Gelest Inc., MCR-C61 , average mol. wt = 1 ,263), (5.01 Og, 3.96mmol) was dissolved in dry CH₂CI₂ (15 ml) in an oven dried Schlenk flask under nitrogen. To this solution was added triethylamine (0.773 ml, 5.56 mmol) and DMAP (2 mg), followed by the addition of a solution of 4-methoxycinnamoyl chloride (from Step 1) in dichloromethane (3 ml). The mixture was then stirred for 3 hours at room temperature and the progress of the reaction followed by TLC. The mixture was then transferred to a separating funnel using CH₂CI₂, washed with 10 ml of 2M HCI, and the aqueous layer re-extracted with CH₂CI₂ (2 x 30 ml). The combined organic layers were then dried (MgSO₄) and the solvent evaporated. The crude product, 9, was used in the next step without purification.

Step 3

[0197] Compound 9 (2.0 g, 1.55 mmol) was dissolved in dry CH₂CI₂ (15 ml). This was followed by addition of triethylamine (0.440 ml, 3.1 mmol) in a dry 50 ml flask under nitrogen. Succinic anhydride (0.190 g, 1.86 mmol) was added portion wise and the mixture stirred at room temperature for 18 hours. The mixture was then transferred to a separating funnel using CH₂CI₂, washed with 10 ml of 2M HCI, and the aqueous layer re- extracted with CH₂CI₂ (2 x 20 ml). The combined organic layers were dried (MgSO₄) and the solvent evaporated. The crude product was then purified using a chromatotron, eluting with 1 % MeOH/CH₂CI₂ → 3% MeOH/CH₂CI₂, giving the product (0.660 g) as colourless oil. Analysis by ¹H NMR indicated the desired product 10 with an average molecular weight (M_n) of 1 ,537. ¹H NMR (400MHz, c/₆-acetone) δ 7.66-7.61 (m, 3H), 6.98-6.96 (m, 2H), 6.42 (d, 1 H, J = 16.0 Hz), 4.14-4.09 (m, 4H), 3.84 (s, 3H), 3.40-3.37 (m, 4H), 2.61 -2.60 (m, 4H), 1.58-1.52 (m, 4H), 1.37-1.33 (m, 4H), 0.93-0.97 (m, 6H), 0.61 -0.56 (m, 4H), 0.12-0.07 (m, SiCH₃).

Step 4

[0198] The synthesis of hydroxyl-functionalised naphthopyran, 1 1 , is described in patent WO 00/15629 (PCT/US99/20663). [0199] Compound 10 with an average molecular weight (M_n) of 1 ,537 (0.400 g, 0.260 mmol) was dissolved in dry dichloromethane (10 ml) in a dry Schlenk-flask under nitrogen to which one drop of DMF was added via syringe. Oxalyl chloride (0.068 ml, 0.78 mmol) was added in one portion and the mixture stirred at room temperature for 30 minutes. The solvent and excess reagent was removed by evaporation in vacuo and the residual reagent removed in vacuo with the aid of dichloromethane (2 x 10 ml), to afford light yellow oil in quantitative yield. This acid chloride product was immediately dissolved in dichloromethane (3 ml) and added to a stirred solution of hydroxyl-functionalised naphthopyran, 1 1 , (0.145 g, 0.260 mmol), triethylamine (0.110 ml, 0.78 mmol) and DMAP (2 mg) in dry dichloromethane (10 ml), under nitrogen. The mixture was stirred for 3 hours at room temperature and the reaction progress monitored by TLC. The mixture was then transferred to a separating funnel using DCM, washed with 10 ml of 2M HCI, and the aqueous layer re-extracted with CH₂CI₂ (2 x 20 ml). The combined organic layers were dried (MgSO₄) and the solvent evaporated. The crude product was purified by flash column chromatography eluting with 100% CH₂CI₂ → 2% MeOH/CH₂CI₂, giving the desired product, Example 8, (130 mg) with an average molecular weight (M_n) of 2,203 as determined by ¹ H NMR. ¹H NMR (400MHz, c/₆-acetone) δ 8.44 (d, 1 H, J = 8.4 Hz), 7.64-7.58 (m, 4H), 7.49-7.44 (m, 9H), 7.31 -7.29, (m, 2H), 6.95-6.89 (m, 6H), 6.45- 5.61 (m, 2H), 4.18-4.07 (m, 6H), 4.07-3.97 (m, 3H), 3.84-3.77 (m, 3H), 3.46-3.34 (m, 6H), 2.63-2.58 (m, 5H), 1.61-1.48 (m, 4H), 1.36-1.33 (m, 4H), 0.89-0.86 (m, 6H), 0.60-0.55 (m, 4H), 0.12-0.08 (m, SiCH₃).

EXAMPLE 9

Spirooxazine hetero Y-branched (poly(dimethylsiloxane)/ methacryloyloxyethyl succinate) conjugate

Step i

[0200] Mono-2-(methacryloyloxy)ethyl succinate 12 (0.600 g, 2.61 mmol) was dissolved in dry dichloromethane (8 ml) in a dry Schlenk-flask under nitrogen. This was followed by the addition of DMF (one small drop) via syringe followed by oxalyl chloride (0.455 ml, 5.21 mmol) in one portion. The mixture was stirred at room temperature for 30 minutes. The solvent and the majority of excess oxalyl chloride was removed by evaporation in vacuo, with the residual reagent removed in vacuo with the aid of dichloromethane. This afforded the acid chloride product, 13, as a light yellow oil in quantitative yield, which was used immediately in the next step.

Step 2

[0201] Compound 4 (Ex. 1 , Step 3, average mol. wt. = 1 ,473), (0.910 g, 0.620 mmol) was dissolved in dry dichloromethane (8 ml) in an oven dried Schlenk flask under nitrogen. To this solution was added triethylamine (0.260 ml, 1.86 mmol) and DMAP (2 mg) followed by the addition of a solution of acid chloride 13 (0.185 g, 0.744 mmol) in dichloromethane (1 ml). The mixture was stirred for 4 hours at room temperature and the progress of the reaction followed by TLC. Trigol mono methyl ether (21 mg, 0.124 mmol) was then added and the mixture stirred for an additional 1 hour. The mixture was transferred to a separating funnel using CH₂CI₂, washed with 10 ml of 2M HCI, and the aqueous layer re- extracted with CH₂CI₂ (2 x 20 ml). The combined organic layers were dried (MgSO₄) and the solvent evaporated. The crude product was purified by column chromatography (silica gel, 10%→50% ethyl acetate/petroleum ether and then 6% MeOH/CH₂CI₂). A total yield of 0.730 g of compound 14 was obtained. ¹H NMR analysis gave an average molecular weight (M_n) of 1 ,685. ¹H NMR (400 MHz, c/₆-acetone) δ 6 .07 (s, 1 H), 5.64-5.63 (m, 1 H), 4.33 (s, 4H), 4.24-4.16 (m, 6H), 3.61 (t, J = 5.00 Hz, 2H), 3.42 (t, J = 6.80 Hz, 2H), 2.61 (d, J = 4.48 Hz, 8H), 1.95-1.90 (m, 3H), 1.69-1.58 (m, 3H), 1.38-1.25 (m, 8H), 0.90-0.83 (m, 4H), 0.61-0.56 (m, 4H), 0.15-0.08 (m, SiCH₃).

Step 3

[0202] Compound 14 (average mol. wt. = 1 ,685), (0.400 g, 2.37 mmol), was dissolved in dry dichloromethane (8 ml) under nitrogen followed by one small drop of DMF via syringe. Oxalyl chloride (0.041 ml, 4.72 mmol) was then added in one portion. The mixture was stirred at room temperature for 35 minutes. The solvent and the majority of the excess oxalyl chloride was removed by evaporation in vacuo with the residual reagent removed in vacuo with the aid of dichloromethane. The acid chloride product was immediately dissolved in dry dichloromethane (2 ml) and added via syringe to a stirred solution of 9'-hydroxy-1 ,3,3-trimethylspiro[indoline-2,3'-[3H]naphtha[2,1 - b][1 ,4]oxazine (0.086 mg, 0.25 mmol) and triethylamine (0.098 ml, 0.71 mmol) in dichloromethane (6ml), under nitrogen. The resulting mixture was stirred at room temperature for 4 hours and the reaction progress followed by tic. The solvent was then evaporated, the residue re-dissolved in chloroform and filtered through a plug of silica. The crude product was purified by flash column chromatography (100% dichloromethane) giving 28 mg of the product, Example 9. ¹H NMR analysis gave an average molecular weight (M_n) of 1 ,961. ¹H NMR (200 MHz, αfe-acetone) δ 8.24 (d, 1 H, J = 2.40 Hz), 7.89 (d, 1 H, J = 8.80 Hz), 7.33-7.25 (m, 4H), 7.23-7.12 (m, 3H), 7.04 (d, 1 H, J = 8.80 Hz), 6.90-6.82 (m, 1 H) 6.64 (d, 1 H, J = 7.70 Hz), 6.08-6.05 (m, 1 H), 5.63-5.60 (m, 1 H), 4.46 (s, 4H), 4.35 (s, 4H), 4.20-4.16 (m, 2H), 3.61 -3.56 (m, 2H), 3.40 (t, 2H, J = 6.80 Hz), 2.80-2.69 (m), 1.90-1.88 (m, 3H), 1.67-1.59 (m, 3H), 1.50 (s, 3H), 1.34 (d, 10H, J = 4.30 Hz), 0.92-0.85 (m, 3H), 0.61 -0.53 (m, 4H), 0.15-0.08 (m, SiCH₃).

EXAMPLE 10

Spirooxazine hetero Y-branched poly(dimethylsiloxane)/hydroxyl conjugate

[0203] Piperazyl-spirooxazine 15 (0.050 g, 0.121 mmol), and mono (2,3-Epoxypropyl)- propylether terminated poly(dimethylsiloxane) 16 (Gelest Inc., MCR-E11 , average mol. wt.: 1 ,323) (0.160 g, 0.121 mmol), were dissolved in dry acetonirile (3.0 ml) in a microwave reactor tube (2.5 - 5.0 ml). The mixture was then heated at 120O for three hours in a microwave reactor (Initiator ™ Biotage microwave reactor). The mixture was cooled and the solvent removed in vacuo. The crude product was purified by flash chromatography (Silica gel) eluting with 100% CH₂CI₂ → 3% MeOH/CH₂CI₂ to give 30 mg of the required product, Example 10. ¹H NMR analysis gave an average molecular weight (M_n) of 1 ,500. ¹H NMR (200 MHz, c/₆-acetone) δ 8.56 (broad d, 1 H, J = 9.04 Hz), 8.06 (broad d, 1 H, J = 7.88 Hz), 7.68 (s, 1 H), 7.58-7.50 (m, 1 H), 7.42-7.34 (m, 1 H), 7.21 - 7.11 (m, 2H), 6.88-6.80 (m, 1 H), 6.62 (t, 2H, J = 3.83 Hz), 3.94-3.87 (m, 1 H), 3.46-3.39 (m, 4H), 3.13-2.96 (m, 10H), 2.74 (broad s, 4H), 2.63-2.43 (m, 2H), 1.70-1.50 (m, 2H), 1.39 (broad s, 8H), 0.92-0.85 (m, 3H), 0.64-0.56 (m, 4H), 0.12-0.08 (m, SiCH₃).

EXAMPLE 11

Naphthopyran hetero Y-branched poly(ethylene glycol mono methyl etherj/dodecenyl conjugate

Step 1

[0204] Polyethylene glycol) methyl ether (av. MW 350) (1.0 g, 2.92 mmol) was dissolved in dry diethyl ether (15 ml) together with triethylamine (0.410 ml, 2.92 mmol) under nitrogen. Dodecen-1 -yl succinic anhydride (0.780 g, 2.92 mmol) was then added in one portion. The reaction mixture was heated at 35O fo r 3 hours. The progress of reaction was followed by TLC. The reaction mixture was transferred to a separating funnel and washed with 1 M HCI (10 ml). The aqueous layer was re-extracted with ether (2 x 20 ml), the combined organic layers dried over Mg₂SO₄ and the solvent removed in vacuo. The crude product was purified by flash chromatography eluting with 2%MeOH/CH₂Cl₂→4%MeOH, giving 850 mg of the desired product, MaJMb (mixture of regioisomers), as a colourless oil. ¹H NMR analysis gave an average molecular weight (M_n) of 578.95.

Step 2

[0205] Compound MaJMb with an average molecular weight (M_n) of 578.95 (0.250 g,

0.432 mmol) was dissolved in dry dichloromethane (12 ml) in a dry Schlenk flask under nitrogen, then one drop of DMF was added via syringe. Oxalyl chloride (0.113 ml, 1.3 mmol) was added in one portion and the mixture stirred at room temperature for 30 minutes. The solvent and a majority of the excess reagent was removed by evaporation in vacuo with the remaining residual reagent removed in vacuo with the aid of dichloromethane (2 x 10 ml), to afford a light yellow oil in quantitative yield. The crude acid chloride product was immediately dissolved in dichloromethane (2 ml) and added to a stirred solution of hydroxyl-functionalised naphthopyran, 1 1 (patent WO 00/15629 (PCT/US99/20663)), (0.242 g, 0.436 mmol), triethylamine (0.181 ml, 1.3 mmol) and DMAP (2 mg) in dry dichloromethane (10 ml), under nitrogen. The mixture was stirred for 18 hours at room temperature and the progress of the reaction followed by TLC. The mixture was transferred to a separating funnel and washed with 1 M HCI (10 ml). The aqueous layer was re-extracted with dichloromethane (2 x 20 ml), the combined organic layers dried over Mg₂SO₄ and the solvent evaporated. The crude product was purified by flash column chromatography, eluting with

100%dichloromethane→6%MeOH/dichloromethane, giving 160 mg of the desired product, Example 11. ¹ H NMR analysis gave an average molecular weight (M_n) of 1 ,246. ¹H NMR (400MHz, CDCI₃) δ 8.39-8.36 (m, 1 H), 7.51 -7.47 (m, 1 H), 7.43-7.30 (m, 10H), 6.87-6.84 (m, 4H), 6.77 (dd, 1 H, J = 9.96 Hz, 1.52 Hz), 6.17 (dd, 1 H, J = 9.96 Hz, 1.52 Hz), 5.47-5.38 (m, 1 H), 5.27-5.21 (m, 1 H), 4.24-4.06 (m, 4H), 3.95-3.81 (m, 2H), 3.78 (s, 6H), 3.66.-3.52 (m, 26H, PEG-OCH₂), 3.37 (s, 3H), 2.91 -2.81 (m, 1 H), 2.69-2.61 (m, 1 H), 2.47-2.15 (m, 3H), 1.96-1.83 (m, 2H), 1.28-1.23 (m, 16H), 0.78 (t, 3H, J = 6.87 Hz).

EXAMPLE 12

Naphthopyran hetero Y-branched (poly(dimethylsiloxane)/ methacryloyloxyethyl succinate) conjugate

[0206] This conjugate was synthesised in the same manner as described in Example 9, using a hydroxyl-functionalised naphthopyran (US Patent 6,399,791 ) in place of spirooxazine in the final step. Analysis of the product by ¹ H NMR gave a spectrum consistent with the molecular structure.

COMPARATIVE EXAMPLE 2

Spirooxazine propionate

[0207] This compound was prepared using the procedure outlined in patent WO 2004/041961 ; PCT/AU03/01453 (2003).

COMPARATIVE EXAMPLE 3

Spirooxazine mono-methacryloyloxyethyl succinate

[0208] 9'-Hydroxy-1 ,3,3-trimethylspiro[indoline-2,3'-[3H]naphtha[2,1 -b][1 ,4]oxazine (0.25 g, 0.73 mmol) was added to dry CH₂CI₂ (10 ml_) followed by the addition of triethylamine (0.11 g, 0.15 ml_, 1.09 mmol) under a nitrogen atmosphere. The acid chloride 13 (Ex. 9, Step 1) (0.181 g, 0.73 mmol) was then added dropwise and the mixture stirred at room temperature for 30 minutes. The solvent was evaporated in vacuo, the residue purified by column chromatography (Silica gel, Et₂O/hexane (4:1 ) to give the product CE3 as a green solid (0.393 g, 97 %). ¹H NMR (200 MHz, de-acetone) δ 1.34 (s, 3H), 1.36 (s, 3H), 1.90 (m, 3H), 2.75 (s overlap, 3H), 2.81 (m overlap, 2H), 3.00 (m, 2H), 4.41 (m, 4H), 5.61 (m, 1 H), 6.08 (m, 1 H), 6.66 (d, 1 H), 6.87 (m, 1 H), 7.04 (d, 1 H), 7.13-7.22 (m, 3H), 7.81 (d overlap, 1 H), 7.83 (s overlap, 1 H), 7.88 (d, 1 H), 8.25 (d, 1 H). COMPARATIVE EXAMPLE 4

Spirooxazine poly(dimethylsiloxane) succinate conjugate

[0209] The synthesis of this compound is outlined in patent WO 2004/041961 ; PCT/AU03/01453 (2003). It is synthesised here using the following alternative procedure.

[0210] 9'-Hydroxy-1 ,3_!3-trimethylspiro[indoline-2,3'-[3H]naphtha[2,1 -b][1 ,4]oxazine (0.924 g, 2.68 mmol) was added to dry CH₂CI₂ (15 ml_) followed by the addition of triethylamine (0.54 g, 0.75 ml_, 5.37 mmol) under an argon atmosphere. Mono Acid Chloride Terminated Polydimethylsiloxane, 3, (Ex. 1 , Step 2) (made from 3.00 g (ca. 2.44 mmol) of Mono Carboxylic Acid Terminated Polydimethylsiloxane, 2, (Ex. 1 , Step 1 )) was then added dropwise and the mixture stirred at room temperature for 30 minutes. The solvent was evaporated in vacuo, the residue re-dissolved in a mixture of Et₂O/hexane (1 :1) and this solution filtered through a plug of silica gel. The solvent was evaporated and the oily residue purified by column chromatography (SiO₂, Et₂O/hexane, 1 :3) to give the product, Mono Spirooxazine Terminated Polydimethylsiloxane, CE4, as a viscous green oil (2.92 g, 77 %). ¹H NMR (200 MHz, d₆-acetone) δ 8.25 (d, 1 H), 7.88 (d, 1 H), 7.83 (s, 1 H), 7.81 (d (overlapping), 1 H), 7.18 (m, 3H), 7.04 (d, 1 H), 6.86 (t, 1 H), 6.66 (d, 1 H), 4.25 (t, 2H), 3.65 (t, 2H), 3.44 (t, 2H), 2.99 (t, 2H), 2.80 (t (overlapping), 2H), 2.77 (s, 3H), 1.62 (m, 2H), 1.35 (m (overlapping), 10H), 0.89 (t, 3H), 0.59 (m, 4H), 0.10 (m, SiCH₃).

COMPARATIVE EXAMPLE 5 α-Spirooxazine, ω-methacrylate functionalised poly(dimethylsiloxane) conjugate

[0211] Compound CE5 falls under the class of compound reported in patent WO 2005/105875, Example 7.

Step 1

[0212] Compound 18 (Gelest Inc., DMS-C15, M_n = 1 ,246) (1.00 g, 0.803 mmol) was added to anhydrous diethyl ether (15 ml) together with triethylamine (0.325 g, 3.21 mmol, 0.45 ml), under nitrogen. Methacryloyl chloride (0.084 g, 0.803 mmol) was added dropwise via syringe at room temperature and stirred for 30 minutes. Succinic anhydride (0.08 g, 0.803 mmol) was added in one portion and the mixture stirred overnight. The solvent was then evaporated and the residue purified by column chromatography (Silica gel, diethyl ether/hexane, 2:3→1 :1 →3:2), of which only the purest fraction (compound 19, 0.259 g) was selected and taken to the next step.

Step 2

[0213] To a solution of compound 19 (0.259 g) in anhydrous dichloromethane (10 ml) was added one small drop of DMF followed by oxalyl chloride (excess). The mixture was stirred at room temperature under nitrogen for 30 minutes. The solvent and excess reagent were evaporated in vacuo and the residue, compound 20, re-dissolved in anhydrous dichloromethane. To this solution was added 9'-Hydroxy-1 ,3,3- trimethylspiro[indoline-2,3'-[3H]naphtha[2,1 -b][1 ,4]oxazine (0.1 g, 0.29 mmol) followed by triethylamine (excess). The mixture was stirred at room temperature for 30 minutes and the solvent evaporated. The crude residue was purified by column chromatography on silica gel to give CE5 (average mol. wt. = 1 ,526, n_PDMs = 10.4). ¹H NMR (400 MHz, de- acetone) δ 0.09-0.13 (m, SiCH₃), 0.59 (m, 4H), 1.34 (s, 3H), 1.36 (s, 3H), 1.62 (m, 4H), 1.92 (s, 3H), 2.77-2.82 (m, 5H), 2.99 (t, 2H), 3.45 (t, 4H), 3.66 (m, 4H), 4.25 (m, 4H), 5.62 (m, 1 H), 6.08 (m, 1 H), 6.66 (d, 1 H), 6.87 (m, 1 H), 7.04 (d, 1 H), 7.14-7.21 (m, 3H), 7.80 (d overlap, 1 H), 7.82 (s overlap, 1 H), 7.88 (d, 1 H), 8.26 (d, 1 H).

COMPARATIVE EXAMPLE 6

Naphthopyran mono-methacryloyloxyethyl succinate

[0214] This compound was synthesised in the same manner as described for Comparative Example 3, using the hydroxyl-functionalised naphthopyran (US Patent 6,399,791) in place of spirooxazine. Analysis of the product by ¹H NMR gave a spectrum consistent with the molecular structure.

COMPARATIVE EXAMPLE 7

Naphthopyran propionate

[0215] This compound was prepared using the procedure outlined in patent WO 2004/041961 (PCT/AU03/01453), using the hydroxyl-functionalised naphthopyran 11 (patent WO 00/15629 (PCT/US99/20663)), in place of spirooxazine. Analysis of the product by ¹H NMR gave a spectrum consistent with the molecular structure. COMPARATIVE EXAMPLE 8

Naphthopyran poly(dimethylsiloxane) succinate conjugate

)

[0216] This compound was synthesised in the same manner as described for Comparative Example 4, using the hydroxyl-functionalised naphthopyran 11 (patent WO 00/15629 (PCT/US99/20663)), in place of spirooxazine. Analysis of the product by ¹H NMR gave a spectrum consistent with the molecular structure.

PHOTOCHROMIC KINETIC ANALYSES (FADE TIMES)

[0217] Compounds were incorporated into a test lens matrix (standard methacrylate formulation comprising 1 :4 weight ratio of poly(ethylene glycol)(400) dimethacrylate (PEGDMA) and ethoxylated bisphenol A dimethacrylate (average number of EO units = 2.6) with 0.4% azobis(isobutyronitrile) (AIBN)). An amount of photochromic compound was dissolved in the matrix formulation at a concentration of 1.2 x 10^"6 mol/g for spirooxazine conjugates and 1.5 x 10^"7 mol/g for naphthopyran conjugates. The mixture was degassed under vacuum, added to a mould and cured in a temperature programmable oven set to initially hold the temperature at 40O for 1 hour and then increase at a rate of 0.2O/min to 95 O where it wa s held for 3 hours. The test lens samples thus obtained were evaluated for their photochromic performance on a light table comprised of a Cary 50 UV-Vis spectrophotometer and a 300W Oriel xenon lamp as an incident UV light source. A series of two filters (Schott WG320 cut-off filter and Edmund Optics band-pass filter U-340) were used to restrict the output of the lamp to a narrow band (320-400 nm). The lamp filters were cooled with water continuously circulating through to a central reservoir and sample lenses maintained at 2OO using a Petier accessory. The samples were monitored at their maximum absorbance of the coloured form. Kinetic scans included 1 minute without UV, 1000 seconds with UV lamp on (160W) and then 80 minutes fade time (without UV exposure).

[0218] These results show the benefit of the use of two different functional groups. In examples 4 and 9 one functional group (PDMS) provides fast switching speed and the other functional group (methacrylate) allows reaction or binding with the host matrix. This allows fast switching without the risk of migration, blooming or phase separation to occurr the lens.

[0219] It is clear from these results that the use of PDMS largely negates the effect of the photochromic dye being tethered to the matrix. CE1 compared to CE2 shows the large effect of the dye being bound closely to the matrix compared to the unbound dye CE2. By increasing the distance between the dye and the reactive group that will bind to the matrix an increase in fade speed is observed (CE3 and CE5) particularly when a PDMS is used between the dye and polymerizable group (CE5). Fastest of all is the unbound PDMS functionalized dye (CE4). However by using the hetero-Y branched structure of the invention (ex 4 and 9) one can obtain significantly faster fade speeds than the closely bound dye (CE1 ), unbound dye (CE2) and longer tethered dye (CE3) with the dye still being relatively closely tethered to the matrix. The materials of the invention are easy to synthesise than CE5 (which also binds to the matrix) with only a small compromise in fade speed. CE4 while the fastest fading dye is can not react with the matrix also may migrate in the matrix.

[0220] The same benefit was observed with a chromene photochromic dye (example 12) where having PDMS also attached to the dye when bound into the matrix (via a reactive methacryalte group) gave substantially better fade performance than the same chromene bound to the matrix without a PDMS attached (CE 6).

Claims

1. A functionalized dye compound comprising a dye moiety and a substituent comprising a multivalent linker covalently bonding the dye moiety to at least two functional groups which are different from one another.

2. A functionalized dye compound according to any one of the previous claims wherein the dye moiety is which is a photochromic.

3. A functionalized dye compound according to any one of the previous claims of formula I

wherein PC is a photochromic dye moiety, L is a multivalent linker, R is a functional group, B is a functional group distinct from R, t is an integer and is 1 or 2 and x is an integer selected from 1 and 2 and preferably the sum of x and t is preferably 2 or 3.

4. A functionalized dye according to claim 4 wherein at least one substituent on the photochromic (PC) is selected from the group of formula Na and lib:

wherein in the formula Ha to lib:

U is a covalent linker to the polymeric group (Poly) and is a bond or a chain containing up to four units defined by any one of formulae Nc to Hf

X' is selected from the group consisting of oxygen, sulfur, amino, alkylamino, Ci to C₄ alkylene, C₁ to C₄ alkyleneoxy, C₁ to C₄alkyleneoxy(C₁ to C₄alkyleneoxy) carbonyl (C₁ to C₄ alkylene);

X" is selected from the group consisting of oxygen, sulfur, amino substituted, alkylamino, C₁ to C₄ oxyalkylene, C₁ to C₄ oxyalkylene(C₁ to C₄ oxyalkylene) and (C₁ to C₄ alkylene) carbonyl; n is an integer from 1 to 3; p which when there is more than one may be the same or different is 0 or 1 ; q is 0 or 1 ;

B is a further functional group; t is 0, 1 or 2 and preferably the sum n+t is no more than 3; and Poly is the position of a covalently bonded low Tg polymer.

5. A functionalized dye compound according to any one of the previous claims wherein the functional groups include distinct groups selected from one or more s groups of functional groups consisting of antioxidants, ultraviolet absorbers, light stabilizers, infrared absorbers antistatic agents, radically polymerizable agent, further dye substituents which are preferably selected from photochromies, host compatibilizers, substituents which modify the nanoenvironment of the dye to modify their behavior and gas barrier polymers.

6. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one living radical polymerization control group selected preferably from RAFT, MADIX, ATRP, Iniferter, Alkoxyamines families of living radical polymerization control groups.

7. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one group selected from hydroxyl, optionally substituted alkylhalo, amino, carboxylic acid, thiol, epoxy, acrylate, methacrylate, styryl

8. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one group that is radically polymerizable and is selected from acrylate, methacrylate, acrylamide, maleimide, styryl, vinyl ether

9. A functionalized dye compound according to any one of the previous claims wherein the dye moiety is a photochromic and the functional groups include a polymeric functional group which changes the nanoenvironment of the dye moiety so as to produce at least a 20% change in the rate of fade.

10. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one hindered phenolic antioxidant preferably selected from the group consisting of 3-(3',5'-di-t-butyl-4'-hydroxy- phenyl)propionic acid, 3-(3'-t-butyl-5'-methyl-4'-hydroxy-phenyl)propionic and the like, and their acid chlorides; and derivatives of sulfur-containing antioxidants preferably selected from monododecyl 3,3'-thiobispropionate, monooctadecyl 3,3'- thiobispropionate, and their acid chlorides.

11. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one ultraviolet absorber selected from the group consisting of derivatives of benzotriazole ultraviolet absorbers preferably selected from 3-[3'- (2"H-benzotriazol-2"-y- l)-4'-hydroxyphenyl]propionic acid, 3-[3'-(2"H-benzotriazol- 2"-yl)-5'-meth- yl-4'-hydroxy-phenyl]propionic acid, 3-[3'-(2"H-benzotriazol-2'-yl)-5'- eth- yl-4'-hydroxyphenyl]propionic acid, 3-[3-(2"H-benzo-triazol-2"-yl)-5'-t-bu- tyl- 4'-hydroxyphenyl]propionic acid, 3-[3'-(5"-chloro-2"H-benzotriazol-2"-- yl)-5'-t- butyl-4'-hydroxyphenyl]propionic acid, 3-[3"-(2"H-benzotriazol-2"- '-yl)-4"-hydroxy- 5"-(1 ',1 '-dimethybenzyl)phenyl]propionic acid, 3-[3"-(2"H-benzotriazol-2"-yl)-4"- hydroxy-5"-(1 ",1 ",3",3"-tetramethylbuty- l)phenyl]propionic acid and the like, and their acid chlorides; triazine ultraviolet absorbers preferably selected from the group consisting of 2-[4'- [(2"-carboxypropioxy-3"-dod- ecyloxypropyl)oxy]-2'-hydrophenyl]-4,6-bis (2', 4'- dimethylphenyl)-1 ,3,5-tr- iazine, 2-[4'-[(2'-phthalyloxy-3'-dodecyloxypropyl)oxy]-2'- hydroxy-phenyl]- -4,6-bis(2',4'-dimethylphenyl)-1 ,3,5-triazine and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides; benzoic acid ultraviolet absorbers preferably selected from the group consisting of benzoic acid, p-aminobenzoic acid and p-dimethylaminobenzoic acid; cinnamic acid ultraviolet absorbers such as cinnamic acid and p-methoxycinnamic acid, salicylic acid, and the like; and their acid chlorides; and photochromies.

12. A functionalized dye compound according to any one of the previous claims wherein at least one of the functional groups comprises a light stabilizer selected from derivatives of hindered amine light stabilizers preferably selected from the group consisting of 2,2,6,6-tetramethyl-4-piperidinol, 1 ,2,2,6,6-pentamethyl-4- piperidinol and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides.

13. A functionalized dye compound according to any one of the previous claims wherein the functional groups comprise antistatic agent preferably comprising polyethylene glycol monomethyl ether, polyethylene glycol-propylene glycol) monomethyl ether, poly(ethylene glycol-propylene glycol)monobutyl ether, N, N- diethylaminoethanol, N,N-diethylaminopropanol- , N,N-diethyl-aminoethoxy- polyethylene glycol and the like, their dicarboxylic acid half ester derivatives, and their acid chlorides; 3-diethylaminopropionic acid, 2,3-epoxypropyl-dimethylamine, and 2,3-epoxypropyl-trimethylammonium chloride.

14. A functionalized dye compound according to any one of the previous claims wherein the functional groups comprise a derivative of nitroxide compound preferably of formula:

wherein R₃ is as defined above, and R₄ and R₅ combine together with the nitrogen to form a heterocyclic group. The atoms in the heterocyclic group (other than the N atom shown in the formula) may be all C atoms or may be C atoms as well as one or more N, O and/or S atoms. The heterocyclic group preferably has 5 or 6 total atoms. The heterocyclic group may be preferably a pyrrole, imidazole, oxazole, thiazole, pyrazole, 3-pyrroline, pyrrolidine, pyridine, pyrimidine, or purine, or derivatives thereof including those compounds wherein R⁴ and R⁵ themselves comprise a substituted or unsubstituted cyclic or heterocyclic groups.

15. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one polymeric group preferably selected from the group consisting of polyethylene, polypropylene, poly(ethylene- propylene) and poly(ethylene-propylene-.α olefins); polyether polymers such as polypropylene glycol, poly(ethylene glycol-propylene glycol), (polyethylene glycol)- (polypropylene glycol) block copolymer and polytetramethylene glycol; polyorganosiloxane polymers such as polydimethylsiloxane, aliphatic polyesters such as polybutylene adipate and polyethylene sebacate; polyesters, for example, aromatic polyesters such as polyethylene isophthalate, polybutylene terephthalate and polyneopentyl terephthalate; polyamides such as 6-nylons and 6,6-nylons; polyvinyl polymers such as polystyrene, styrene copolymers and polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, polyvinyl butyral; (meth)acrylic (co)polymers such as acrylate ester (co)polymers, methacrylate ester (co)polymers and acrylic compound-styrene copolymers; polysilicone polymers; polyurethane resins; polyurea resins; epoxy resins; melamine resins; cellulose resins; chitosan resins; copolymers of two or more of the monomers making up the above-described polymers; and block copolymers formed of two or more of the above-described polymers.

16. A functionalized dye compound according to any one of the previous claims wherein the functional groups include at least one polymeric groups comprising at least five monomer units and preferably at least seven monomer units.

17. A functionalized dye compound according to any one of the previous claims wherein the linker group is derived from a compound containing one or more types of reactive groups selected from nucleophilic and electrophilic groups preferably selected from the group consisting of acid groups and their derivatives such as acid chlorides; anhydrides and the like; alcohols; thiols; amines and vinyl groups

18. A functionalized dye compound according to any one of the previous claims wherein the liker group is selected from the group consisting of phosphine, polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine and both linear and branched polyethylenimine; primary amines such as methylamine, hydroxyethylamine, octadecylamine and polymethylenediamines such as hexamethylenediamine; polyaminoalkylarenes such as 1 ,3,5-tris(aminomethyl)benzene; tris(aminoalkyl)amines such as tris(aminoethyl)amine; heterocyclic amines such as imidazolines and piperidines; and various other amines such as hydroxyethylaminoethylamine, mercaptoethylamine, morpholine, piperazine, amino derivatives of polyvinylbenzyl chloride and other benzylic polyamines such as tris(1 ,3,5-aminomethyl)benzene. Other suitable nucleophilic linkers include polyols such as the aforementioned pentaerythritol, ethylene glycol and polyalkylene polyols such as polyethylene glycol and polypropylene glycol; 1 ,2-dimercaptoethane and polyalkylene polymercaptans; thiophenols, and phenols; polyols particularly hydroxyl phenols are preferred for the preparation of polyether substituents; benzylic polyamines such as tris(1 ,3,5-aminomethyl)benzene; alkanolamines such as ethanolamine; and aziridine and derivatives thereof such as N-aminoethyl aziridine:substituted anhydrides; substituted epoxides; polyhydroxy acids such as 2,2- Bis(hydroxymethyl)propionic acid and dihydroxy benzoic acids.

19. A functionalized dye compound according to any one of the previous claims wherein the linker is selected from the group consisting of the CrC₄ alkyl esters of various polycarboxylic acids such as benzene tricarboxylic acid, oxalic acid, terphthalic acid and carboxylic acids and derivatives represented by the formula I:

wherein R which when there is more than one R may be the same or different is selected from the group consisting of hydroxyl, amino, alkylamino, lower alkoxy, acyloxy and substituted acyloxy particularly halo acyl such as 2-bromoisobutryl; R¹ is selected from hydroxyl and leaving groups such as chloro; Y is hydrocarbyl or a hydrocarbon polyl wherein the hydrocarbon radical is alkyl, aryl, cycloalkyl, alkylene, arylene, cycloalkylene, and corresponding trivalent, tetravalent, pentavalent and hexavalent radicals of such hydrocarbons; and Z is a whole number from 1 to 6, t is a whole number from 1 to 6 and z plus t is at least 3.

20. A functionalized dye compound according to claim 17 wherein in the compound of formula I the integer z is one and is reacted with the dye moiety and t is at least 2 and more preferably is 2 or 3 and is reacted with the functional groups.

21. A functionalized dye compound according to any one of the previous claims wherein the dye moiety is a photochromic moiety selected from the group consisting of: chromenes such as those selected from the group consisting of naphthopyrans, benzopyrans, indenonaphthopyrans and phenanthropyrans; spiropyrans such as those selected from the group consisting of spiro(benzindoline) naphthopyrans, spiro(indoline)benzopyrans, spiro(indoline)- naphthopyrans, spiroquinopyrans, and spiro(indoline)pyrans and spirodihydroindolizines; spiro-oxazines such as those selected from the group consisting of spiro(indoline)naphthoxazines, spiro(indoline)- pyridobenzoxazines, spiro(benzindoline)pyridobenzoxazines, spiro(benzindoline)naphthoxazines and spiro(indoline)- benzoxazines; fulgidies, fulgimides; anils; perimidinespirocyclohexadienones; diarylperfluorocyclopentenes; diarylcyclopentenes; diheteroarylcyclopentenes; diheteroarylperfluoro- cyclopentenes; stilbenes; thioindigoids; azo dyes; diarylperfluorocyclopentenes; and diarylethenes.

22.A photochromic polymeric composition comprising a matrix selected from the group consisting of polymers of Tg of at least 5O⁰C and monomer compositions which on curing provide polymers of Tg of at least 5O⁰C; and a photochromic polymer according to any one of claims 1 to 10.

23.A photochromic composition according to claim 22 wherein the photochromic polymer comprises a functional group which is reactive with the matrix to thereby covalently bond the photochromic polymer to the matrix.

24.A photochromic composition according to claim 23 wherein the photochromic is of formula Na or lib least one substituent on the photochromic (PC) is selected from the group of formula Na and Hb:

wherein in the formula Na to lib are as defined in claim 4 and the subtituent B comprises a group reactive with the matrix.

25.A photochromic composition according to claim 22 wherein the photochromic polymer remains unbound to the matrix.

26.A photochromic composition according to claim 22 wherein the photochromic compound is imbibed into a solid polymeric matrix which is at least partly cured.

27.A photochromic composition according to any one of claim 16 to 19 wherein the matrix is selected from the group consisting of homopolymers and copolymers of polyol(allyl carbonate) monomers, homopolymers and copolymers of polyfunctional acrylate monomers, polyacrylates, poly(alkylacrylates), cellulose acetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, polyvinyl acetate), poly(vinylalcohol), poly(vinylchloride), poly(vinlylidene chloride), polyurethanes, polycarbonates, poly(ethylene-terephthalate), polystyrene, copoly(styrene-methylmethacrylate), copoly(styrene-acrylonitrile), poly(vinylbutyrl), and homopolymers and copolymers of diacylidene pentaerythritol, and blends of two or more thereof and monomer compositions for preparing such polymers