Lignin-containing sealant and/or coating compositions from renewable sources

1. A lignin-containing composition comprising:

10 to 50 percent by weight of lignin;

10 to 50 percent by weight of a liquid C2-C4 polyol; and

10 to 50 percent by weight of an acrylic resin;

wherein the percentages by weight are expressed relative to the total dry weight of the composition,

wherein at least 90 percent of the total dry weight of the composition consists of lignin, liquid C2-C4 polyol, acrylic resin and optionally a filler, and

wherein the total dry weight of the composition amounts to 100 percent.

2. The lignin-containing composition according to claim 1 , wherein the composition is solvent free.

3. The lignin-containing composition according to claim 1 , further comprising a non-aqueous protic or polar aprotic solvent.

4. The lignin-containing composition according to claim 3 , comprising 50 to 500 percent by weight of the solvent, relative to the total dry weight of the composition, wherein the total dry weight of the composition amounts to 100 percent.

5. The lignin-containing composition according to claim 1 , further comprising 1 to 50 percent by weight of a filler selected from wood flour or a solid polyol.

6. The lignin-containing composition according to claim 5 , wherein the filler is wood flour.

7. The lignin-containing composition according to claim 1 , wherein the lignin is selected from kraft lignin, lignin obtained by at least partially neutralising kraft black liquor using carbon dioxide in order to precipitate the lignin, sulphite lignin, soda lignin, organosolv lignin, lignin from cellulosic ethanol production, or mixtures thereof.

8. The lignin-containing composition according to claim 1 , wherein the lignin is a non-derivatised lignin.

9. The lignin-containing composition according to claim 1 , wherein the liquid C2-C4 polyol is selected from ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, glycerol, or combinations thereof.

10. The lignin-containing composition according to claim 1 , wherein the acrylic resin comprises a monomer selected from methyl acrylate, ethyl acrylate, butyl acrylate, 2-chloroethyl vinyl ether, 2-ethylhexyl acrylate, trimethylolpropane triacrylate, acrylonitrile, methacrylate, butyl methacrylate, hydroxyethyl methacrylate, or combinations thereof.

11. A sealant and/or coating composition comprising the composition of claim 1 .

12. A process for forming a sealed joint comprising the steps of:

i. providing a joint, wherein the joint comprises an area where two substrates are mechanically or adhesively joined, and/or said joint comprises an area where one substrate abuts another substrate, wherein each of said substrates is independently selected from metal, plastic, glass, wood, stone, clay or ceramic; and

ii. applying the lignin-containing composition according to claim 1 to said joint and heating the applied composition at a predetermined temperature for a predetermined time.

13. The process according to claim 12 , wherein the predetermined temperature is 100 to 120° C. and wherein the predetermined time is 10 to 50 minutes.

14. The process according to claim 12 , wherein the joint is between two metal substrates.

15. A process for forming a coated surface comprising the steps of applying the lignin-containing composition according to claim 1 to a surface of a substrate and heating the applied composition at a predetermined temperature for a predetermined time, wherein the substrate is selected from metal, plastic, glass, wood, stone, clay or ceramic.

16. The process according to claim 15 , wherein the predetermined temperature is 100 to 120° C., and wherein the predetermined time is 10 to 50 minutes.

17. The process according to claim 15 , wherein the surface of the substrate is a surface of a metal substrate.