Photochromic polymers

1. A photochromic polymer comprising at least two photochromic moieties linked by a straight or branched chain polymer selected from the group consisting of a homo-polyester, a co-polyester, and a co-polyester-polyether.

2. A photochromic polymer according to claim 1 , wherein the polymer is poly(C 1 to C 10 acyloxy); poly[(C 1 to C 10 acyloxy)-co-(C 1 to C 10 acyloxy)]; poly(acyloxy)alkoxide; poly[(C 1 to C 10 alkylene)-co-(C 1 to C 10 acyloxy); poly(C 1 to C 10 alkylene)-block-poly(C 1 to C 10 acyloxy); poly[(C 1 to C 10 alkylene oxide)-co-(C 1 to C 10 acyloxy)]; and poly(C 1 to C 10 alkylene oxide)-block-poly(C 1 to C 10 acyloxy).

3. A photochromic polymer according to claim 1 of formula I:

(PC-L a -(Q) n -L b ) Z X  (I)

wherein (Q) n is a polymer comprising a polyester each independently selected from the group consisting poly(C 1 to C 10 acyloxy); poly[(C 1 to C 10 acyloxy)-co-(C 1 to C 10 acyloxy)]; poly(acyloxy)alkoxide; poly[(C 1 to C 10 alkylene)-co-(C 1 to C 10 acyloxy); poly(C 1 to C 10 alkylene)-block-poly(C 1 to C 10 acyloxy); poly[(C 1 to C 10 alkylene oxide)-co-(C 1 to C 10 acyloxy)]; and poly(C 1 to C 10 alkylene oxide)-block-poly(C 1 to C 10 acyloxy); and wherein n of (Q) n is an integer from 1 to 50;

Z is an integer from 2 to 8;

L a and L b are each independently a bond or a linker;

PC are independently selected photochromic moieties; and

X is a bond, or a linear or branched hydrocarbon comprising from 1 to 20 carbon atoms or a hydrocarbon ether or polyether of 2, 3 or 4 hydrocarbon units each of 3 to 6 carbon atoms joined through ether linkages and together providing covalent bonds to from 2 to 8 (PC-L 1 -(Q) n -L 2 ) Z units.

4. A photochromic polymer according to claim 3 wherein X is a hydrocarbon of formula:

C m H 2m+2-Z

wherein m is from 1 to 6 and Z is as defined in claim 3 .

5. A photochromic polymer according to claim 3 wherein Z is from 2 to 8 and X is selected from the group consisting of: ethyl, propyl, butyl, pentyl, hexyl, —(CH 2 ) 1-8 O(CH 2 ) 1-8 —, wherein Z is 2;

wherein Z is 3; and

wherein Z is from 4, 6 or 8.

6. A photochromic polymer according to claim 3 wherein the photochromic polymer is of formula IIIa, IIIb or IIIc:

PC 1 -L a1 -(Q 1 ) n1 -L b1 -X 1 -L b2 -(Q 2 ) n2 -L a2 -PC 2   (IIIa)

wherein X 1 is selected from the group consisting of ethyl, propyl, butyl, pentyl, hexyl and —(CH 2 ) 1-8 O(CH 2 ) 1-8 —;

wherein X 2 is a linear or branched hydrocarbon of formula C m H 2m-1 ; wherein m is from 1 to 6; and

wherein X 3 is a linear or branched hydrocarbon of formula C m H 2m-2 ; wherein m is from 1 to 6;

and wherein (Q 1 ) n1 , (Q 2 ) n2 , (Q 3 ) n3 and (Q 4 ) n4 are as defined for Q; n1, n2, n3 and n4 of (Q 1 ) n1 , (Q 2 ) n2 , (Q 3 ) n3 and (Q 4 ) n4 , respectively, are each independently an integer from 1 to 50; and

L a1 , L a2 , L a3 and L a4 are as defined above for L a ;

L b1 , L b2 , L b3 and L b4 are as defined above for L b ;

PC 1 , PC 2 , PC 3 and PC 4 is as defined for PC.

7. A photochromic polymer according to claim 6 , wherein

-(Q 1 ) n1 -L b1 -X 1 -L b2 -(Q 2 ) n2 -

of formula IIIa is dihydroxy poly(caprolactone) or poly[di(ethylene glycol) adipate].

8. A photochromic polymer according to claim 6 , wherein

of formula IIIb is poly caprolactone triol.

9. A photochromic polymer according to claim 3 wherein L a and L b in formula I may be a bond or a linker; wherein the linker is selected from the group consisting of —(CH 2 ) x —, —O—, —N(R 4 )—, —S—, —Si—, —C(═O)—, —C(═S)—, —OC(═O)—, —N(R 4 )C(═O)—, —O(CH 2 ) x O—, —OC(═O)—(CH 2 ) x —C(═O)O—, —OC(═O)—O—C(═O)O— a linear or branched hydrocarbon comprising from 1 to 20 carbon atoms, a hydrocarbon ether or polyether of 2, 3 or 4 hydrocarbon units each of 3 to 6 carbon atoms joined through ether linkages, a hydrocarbon ester or polyester of 2, 3 or 4 hydrocarbon units each of 3 to 6 carbon atoms joined through ester linkages; wherein R 4 is H or an alkyl group of 1 to 6 carbon atoms, and x is an integer from 1 to 10.

10. A photochromic polymer according to claim 9 , wherein L a is a group selected from the following formula:

11. A photochromic polymer according to claim 3 , wherein the photochromic moieties are independently selected from the group consisting of naphthopyrans, spiropyrans and spirooxazines.

12. A photochromic polymer according to claim 3 , wherein the photochromic moieties are independently selected from the moieties of formula IVa to IVd:

wherein R 5 and R 6 independently represent hydrogen, C 1-10 alkyl, C 1-10 alkoxy, C 1-10 hydroxyalkoxy, C 1-10 alkoxy(C 1-10 )alkoxy, phenyl, C 1-10 alkoxyphenyl, halogen, C 1-5 haloalkyl, C 1-5 alkylamino, C 1-5 dialkylamino, arylamino, diarylamino, aryl C 1-5 alkylamino, or a cyclic amino group;

R 5a and R 6a are hydrogen or together with R 5 and R 6 respectively may form a carbocyclic or heterocyclic ring of 5 or 6 constituent ring members and optionally up to two heteroatoms selected from oxygen, sulfur and —N(R 27 )— wherein R 27 is selected from hydrogen and C 1-10 alkyl;

R 7 represents hydrogen, C 1-10 alkyl, up to C 20 cycloalkyl, up to C 20 bicycloalkyl, C 2-10 alkenyl, C 1-10 alkoxy, C 1-10 hydroxyalkyl, C 1-10 alkoxy(C 1-10 )alkyl, C 1-10 aminoalkyl, C 1-20 alkoxycarbonyl, carboxyl, halogen, aryloxycarbonyl, formyl, acetyl or aroyl;

R 8 represents, phenyl, C 1-10 alkoxyphenyl, C 1-10 dialkoxyphenyl, C 1-10 alkylphenyl, C 1-10 dialkylphenyl or one of the groups specified for R 7 ; or R 7 and R 8 together form a cyclic structure of the type

R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 16 , R 17 , R 18 , R 19 , R 20 , R 23 , R 24 , R 25 and R 26 are as defined for R 5 and R 6 ; and

R 15 , R 21 and R 22 represents linear or branched C 1-10 alkyl, C 1-10 hydroxyalkyl, or together form a C 5-7 ring.

13. A photochromic polymer of formula I according to claim 3 wherein the photochromic moieties (PC) are independently selected from the group consisting of

1,3-dihydro-3,3-dimethyl-1-neopentyl-6′-(4″-N-ethyl, N-(hydroxylethyl)anilino)spiro[2H-indole-2,3′-3H-naphtho[1,2-b][1,4]oxazine;

3-(4′-methoxyphenyl),3-(4″-(hydroxyethoxy)phenyl)-6-morpholino-3Hnaphtho[2,1-b]pyran;

3-(4′-methoxyphenyl),3-(4″-(hydroxyethoxy)phenyl)-6-morpholino-3Hnaphtho[2,1-b]pyran;

1,3-dihydro-3,3-dimethyl-1-isobutyl-9′-hydroxy-sprio[2H-indole-2,3′-3Hnaphtho[2,1-b][1,4]oxazine;

2-(4′-pyrrolidinophenyl)-2-phenyl-5-hydroxymethyl-6-anisyl-9-methoxy-2Hnaphtho[1,2-b]pyran;

2,2-bis(4′-methoxyphenyl)-5-hydroxymethyl-6-methyl-2H-naphthol[1,2-b]pyran;

(2-(4′-pyrrolidinophenyl)-2-phenyl-5-hydroxymethyl-6-anisyl-9-methoxy-2Hnaphtho[1,2-b]pyran;

3-phenyl-3-(4′-(hydroxyethoxy)phenyl)-6-morpholino-3H-naphtho[2,1-b]pyran;

1,3-dihydro-3,3-dimethyl-1-neopentyl-9′-hydroxy-spiro[2H-indole-2,3′-3Hnaphthol[2,1-b][1,4]oxazine]; and

2,2-Bis(4′-methoxyphenyl)-5-hydroxymethyl-6-methyl-2H-naphtho[1,2-b]pyran.

14. A photochromic polymer according to claim 3 , wherein the molecular weight of the polymer is in the range of 200 to 10,000.

15. A photochromic polymer according to claim 3 , wherein the glass transition temperature is less than 25° C.

16. A photochromic polymeric composition comprising a photochromics polymer according to claim 1 and a host polymer.

17. A photochromic polymeric composition according to claim 16 which is free from polydialkylsiloxane polymer.

18. A photochromic lens comprising a photochromic polymeric composition according to claim 16 .

19. A photochromic polymer according to claim 3 wherein X is linear or branched hydrocarbon of from 2 to 6 carbon atoms.

20. A photochromic polymer of claim 6 wherein X 2 is selected from:

and X 3 is selected from: