A copolymer containing repeat units formed from the monomers (I) and (II), wherein each R 1 , if present, is independently hydrogen or hydrocarbyl; r is 0, 1 or 2; s is either 2 or 3; R 2 –R 4 are each independently hydrogen or hydrocarbyl; R 5 and R 6 are each independently hydrogen, halo or hydrocarbyl; P d − is the anion formed by loss of a proton from a proton donating group P d —H; Z is either a bond or hydrocarbyl; R 7 and R 8 are each independently hydrogen, halo or hydrocarbyl; and either (a) A is an electron accepting group and W is either hydrogen or hydrocarbyl, (b) W is an electron accepting group and A is either a bond or hydrocarbyl or (c) both A and W are electron accepting groups. The invention also provides a method for preparing the copolymer by polymerising a mixture of (I) and (II) or their non-ionised precursors, preferably by exposure to ultraviolet radiation. The invention also relates to the uses of the copolymer in adhesive, coating, sealant and stereolithographic compositions
1. copolymer containing repeat units formed from both the monomer (I):
wherein each R 1 , if present, is independently either hydrogen or a hydrocarbyl group; r is 0, 1 or 2; s is either 2 or 3; R 2–R 4 are each independently hydrogen or a hydrocarbyl group; and R 5 and R 6 are each independently either hydrocarbyl, halo or hydrogen;
and the monomer (II):
wherein P d 31 is the anion formed by loss of a proton from a proton donating group P d —H; Z is either a bond or a hydrocarbyl group; R 7 and R 8 are each independently hydrogen, a halo group or a hydrocarbyl group; and either (a) A is an electron accepting group, in which case. W is either hydrogen or a hydrocarbyl group, (b) W is an electron accepting group and A is either a bond or a hydrocarbyl group or (c) both A and W are electron accepting groups;
wherein either:
(a) the monomer (II) has the general formula (IX):
in which B 1 is a bridging group of valency v, v is an integer from 2 to 8 and the groups —P d H may be wholly or partially present as the deprotonated analogues —P d 31 ; or
(b) the monomer (I) has the formula (X):
in which B 2 is a bridging group of valency a, and a is an integer from 2–8, or
(c) both monomer (I) and (II) are selected from (IX) and (X) respectively, with the proviso that B 2 is not a phenyl or a substituted phenyl group or an alkylene group containing 2–8 carbon atoms.
2. A copolymer according to claim 1 , wherein in the monomer (II) the proton donating group P d —H is OH.
3. A copolymer according to claim 1 wherein in the monomer (II) an electron accepting group A or W is, or contains, C═O, O═S═O or P═O.
4. A copolymer according to claim 1 wherein in the monomer (II) Z is a bond.
5. A copolymer according to claim 1 , wherein in the monomer (II) R 7 and R 8 are both hydrogen.
6. A copolymer according to claim 1 , wherein the monomer (II) is an optionally substituted acrylate, methacrylate, itaconate, vinyl suiphonate or vinyl phosphonate.
7. A copolymer according to claim 1 , wherein the copolymer is formed from said monomer (II) of said formula (IX).
8. A copolymer according to claim 7 , wherein v is 2.
9. A copolymer according to claim 8 , wherein B′ is H 2 C—C(O)—O—(CH 2 ) w —O—C(O)—CH 2 , where w is an integer from 1 to 20, or H 2 C—C(O)—O—CH 2 —(CF 2 ) y —CH 2 —O—C(O)—CH 2 , where y is an integer from 1 to 10.
10. A copolymer according to claim 1 , wherein in the monomer (I)r is 1.
11. A copolymer according to claim 1 , wherein in the monomer (I), R 2 –R 6 are all hydrogen.
12. A copolymer according to claim 1 , wherein in the monomer (I), R 1 is either hydrogen or hydroxyalkyl.
13. A copolymer according to claim 1 , wherein in the monomer (I), s is 2.
14. A copolymer according to claim 13 , wherein in the monomer (I), R 1 is hydrogen.
15. A copolymer according to claim 13 , wherein in the monomer (I), R 1 is not hydrogen.
16. A copolymer according to claim 1 , wherein in the monomer (I), s is 3.
17. A copolymer according to claim 1 , wherein the copolymer is formed from said monomer (I) of said formula (X).
18. A copolymer according to claim 17 , wherein a is 2.
19. A copolymer according to claim 18 , wherein B 2 is —(CH2) b where b is an integer from 1 to 20.
20. A copolymer according to claim 1 , containing stoichiometrically equivalent amounts of the monomers (I) and (II).
21. A copolymer according to claim 1 , containing a stoichiometric excess of the monomer (II).
22. A copolymer according to claim 1 , containing at least 40% w/w of the monomer (I).
23. A copolymer according to claim 1 , containing at least 40% w/w of the monomer (II).
24. A copolymer according to claim 1 , which is water impermeable or substantially so.
25. A method for preparing a copolymer according to claim 1 , the method comprising polymerising a mixture of the monomers (I) and (II).
26. A method according to claim 25 , wherein the monomer mixture is prepared by mixing together the precursor allylamine (III):
and the proton donor (IV):
wherein R 1 –R 8 , r, s, —P d H, Z, A and W are as defined in any one of claims 1 to 25 .
27. A method according to claim 25 , wherein the monomer mixture is prepared by mixing together the already ionised monomers (I) and (II), each stabilised by a suitable counterion.
28. A method according to claim 25 , wherein the monomer mixture is polymerised by exposure to ultraviolet radiation.