Liquid electrophotographic adhesive composition

1. A liquid electrophotographic adhesive composition comprising:

a thermoplastic resin;

at least 70 wt % to about 90 wt % of a moisture activatable adhesive by total solids of the composition; and

an insulating, non-polar, non-aqueous liquid carrier;

wherein the adhesive composition is transparent and substantially free from pigment;

and wherein the moisture activatable adhesive is selected from the group consisting of cellulose derivatives, natural gums, gelatin, and combinations thereof.

2. A composition according to claim 1 , wherein the moisture activatable adhesive is selected from the group consisting of hydroxyl methyl cellulose, 2-hydroxy ethyl cellulose, hydroxypropyl methyl cellulose, ethyl hydroxyethyl cellulose, methyl (2-hydroxypropyl) cellulose, methyl cellulose, xantham gum, agar, and acacia gum.

3. A composition according to claim 1 , wherein the thermoplastic resin comprises a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid.

4. A composition according to claim 1 comprising the thermoplastic resin in an amount from about 15 wt % to about 70 wt % by total solids of the composition.

5. A composition according to claim 1 comprising a charge director.

6. A composition according to claim 1 comprising a charge adjuvant.

7. A method comprising:

forming an adhesive image on a print substrate by electrophotographically printing the liquid electrophotographic adhesive composition of claim 1 on to the print substrate;

activating the adhesive image by applying water to the adhesive image; and

applying an embellishing material to the activated adhesive image such that the embellishing material adheres to the activated adhesive image.

8. A method according to claim 7 , wherein the adhesive image has a thickness of about 1 μm to about 15 μm.

9. A method according to claim 7 , wherein activating the adhesive images comprises applying water to the adhesive image in an amount of about 0.05 to about 0.5 g/m 2 .

10. A method according to claim 7 , wherein applying an embellishing material to the activated adhesive image comprises applying the embellishing material to the activated adhesive image at a temperature of less than about 50° C.

11. A method according to claim 7 , comprising forming an ink image on a print substrate by electrophotographically printing a liquid electrophotographic ink composition comprising a thermoplastic resin, a pigment and a liquid carrier on to the print substrate such that the ink image is disposed on the print substrate and the adhesive image is disposed on the ink image.

12. A liquid electrophotographic printing composition set comprising:

the liquid electrophotographic adhesive composition of claim 1 ;

and

a liquid electrophotographic ink composition comprising:

a thermoplastic resin;

a pigment; and

a liquid carrier.

13. A set according to claim 12 , wherein the thermoplastic resin of the liquid electrophotographic adhesive composition comprises a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid and the thermoplastic resin of the liquid electrophotographic ink composition comprises a copolymer of an alkylene monomer and a monomer selected from acrylic acid and methacrylic acid.

14. A composition according to claim 1 , wherein the moisture activatable adhesive is selected from the group consisting of hydroxy methyl cellulose and acacia gum.

15. A liquid electrophotographic adhesive composition comprising:

a thermoplastic resin;

at least about 70 wt % to about 90 wt % of a moisture activatable adhesive by total solids of the composition; and

an insulating, non-polar, non-aqueous liquid carrier;

wherein the adhesive composition is transparent and substantially free from pigment;

and wherein the moisture activatable adhesive is acacia gum.