Ink-jet printing process

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 in a localised manner to form an image on the substrate; and

(b) applying to the substrate a composition comprising a liquid medium and a poly(C 3-18 -hydrocarbyl monoguanidine) or a salt thereof by means of an ink-jet printer.

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

3. A process according to any one of the preceding claims wherein the poly(C 3-18 -hydrocarbyl monoguanidine) 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 2-18 -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.

4. A process according to claim 1 or 2 wherein the poly(C 3-12 -hydrocarbyl monoguanidine) comprises one or more groups of Formula (3) or salts thereof:

wherein:

n is 2 to 50.

5. A process according to claim 1 or 2 wherein the composition used in step (b) further comprises a binder.

6. A process according to claim 1 or 2 wherein the composition used in step (b) contains a crosslinker.

7. A process according to claim 1 or 2 wherein step (b) of the process is performed before step (a) or simultaneously with step (a).

8. A process according to claim 1 or 2 wherein the ink contains less than 500 ppm in total of divalent and trivalent metal ions (other than any divalent and trivalent metal ions bound to a component of the ink).

9. A process according to claim 1 or 2 wherein the ink of step (a) comprises a liquid medium and a colorant with at least two groups selected from —COOH, —PO 3 H 2 , morpholinyl and piperazinyl or salts thereof.

10. A substrate printed with an image by means of the process according to claim 1 or 2 .

11. A fixing composition for use in an ink-jet printer comprising a poly(C 3-18 -hydrocarbyl monoguanidine), a liquid medium and a binder, wherein the liquid medium comprises an organic solvent.

12. A fixing composition according to claim 11 which contains less than 500 ppm divalent and trivalent metal ions (other than any divalent and trivalent metal ions bound to a component of the fixing composition) and which has been filtered through a filter having a mean pore size below 10 μm.

13. A fixing composition according to either claim 11 or 12 which has a viscosity of less than 20 cP at 25° C.

14. An ink-jet printer cartridge comprising a plurality of chambers and a fixing composition, wherein the fixing composition is contained in a chamber of the ink-jet printer cartridge and the fixing composition is as defined in claim 11 or 12 .

15. A fixing composition according to claim 11 wherein the poly(C 3-18 -hydrocarbyl monoguanidine) 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 2-18 -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.

16. A fixing composition according to claim 11 wherein the poly(C 3-18 -hydrocarbyl monoguanidine) comprises one or more groups of Formula (3) or salts thereof:

wherein:

n is 2 to 50.

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

(a) a first liquid comprising:

(i) 0.01 to 50 parts of a poly(C 3-18 -hydrocarbyl monoguanidine);

(ii) 50 to 99.8 of a liquid medium selected from water, one or more water-soluble organic solvents and a mixture of water and one or more water-soluble organic solvents; and

(iii) 0 to 50 parts of a binder;

wherein the parts are by weight and the total number of parts (i)+(ii)+(iii)=100; and

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

18. 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 17 .

19. A set of liquids according to claim 17 wherein the poly(C 3-18 -hydrocarbyl monoguanidine) 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 2-18 -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.

20. A set of liquids according to claim 17 wherein the poly(C 3-18 -hydrocarbyl monoguanidine) comprises one or more groups of Formula (3) or salts thereof:

wherein:

n is 2 to 50.