Compositions and processes

1. An ink-jet printing process comprising the steps (a) and (b) in any order or simultaneously:

(a) applying an ink to a substrate by means of an ink-jet printer to form an image on the substrate; and

(b) applying to the substrate a fixing composition comprising a liquid medium and a polymer containing a plurality of monoguanide and/or biguanide groups by means of an ink-jet printer wherein the fixing composition has a concentration of 0.1 wt % to 10 wt % of the polymer containing the plurality of monoguanide and/or biguanide groups;

wherein the fixing composition has a chloride concentration less than 400 ppm by weight.

2. A process according to claim 1 wherein the fixing composition is applied to the substrate in a localised manner and the areas where the ink and composition are applied in steps (a) and (b) are substantially coextensive.

3. A process according to claim 1 wherein the polymer containing a plurality of monoguanide and/or biguanide groups is a polymonoguanide and/or a polymeric biguanide.

4. A process according to claim 1 wherein the polymer containing a plurality of monoguanide and/or biguanide groups is a polymonoguanide.

5. A process according to claim 4 wherein the polymonoguanide comprises a plurality of groups of Formula (1) and/or groups of Formula (2) or salts thereof:

wherein:

each m independently is 0 or 1;

each y independently is a C 3-18 -hydrocarbyl group;

A and B are hydrocarbyl groups which together comprise a total of 3 to 18 carbon atoms; and

each R independently is hydrogen, optionally substituted alkyl or optionally substituted alkoxy.

6. A process according to claim 1 wherein the polymonoguanide has been obtained by a process comprising melt polymerisation of a C 3-18 -hydrocarbyl diamine with guanidine salt other than guanidine hydrochloride.

7. A process for preparing a polymonoguanide comprising solvent polymerization of C 3-18 -hydrocarbyl diamine with guanidine salt other than guanidine hydrochloride, wherein solvent has a Log P of between −1.5 and =1, and wherein the polymonoguanide has a chloride concentration less than 400ppm by weight.

8. A polymonoguanide obtained by a process according to claims 7 .

9. A composition comprising:

(a) from 0.1 to 10 parts of polymer containing a plurality of monoguanide and/or biguanide groups or salt thereof;

(b) from 0 to 10 parts of a binder;

(c) from 30 to 60 parts of a water-soluble organic solvent; and

(d) from 35 to 80 parts water;

wherein all parts are by weight and the total number of parts (a)+(b)+(c)+(d)−100 and the composition contains less than 400 ppm by weight of chloride ions.

10. A substrate printed with an image by means of the process according to claim 1 .

11. A set of liquids suitable for use in an ink jet printer comprising:

(a) a fixing composition according to claim 9 ; and

(b) an ink comprising a colorant and a liquid medium.

12. An ink jet printer cartridge comprising a plurality of chambers and a set of liquids, wherein the liquids are contained in individual chambers of the ink jet printer cartridge and the set of liquids is as defined in claim 11 .

13. A process for preparing a polymonoguanide comprising melt polymerization of C 3-18 -hydrocarbyl diamine with guanidine salt other than guanidine hydrochloride, wherein the polymonoguanide has a chloride concentration less than 400 ppm by weight.

14. A process according to claim 7 wherein the polymerisation is a melt polyermisation performed at a temperature of 100° C. to 200° C.

15. A polymonoguanide obtained by process according to claim 1 .