Adhesive composition
The invention provides for an adhesive composition that can both be used as melt adhesive composition and as drying adhesive composition. Such an adhesive composition comprises a thermoreversible gelling starch, a bonding starch and a plasticizer.
1. Method for adhering a first substrate to a second substrate comprising the steps of
providing an aqueous adhesive composition comprising a thermoreversible gelling starch, a bonding starch, and a plasticizer, wherein the composition has a water content of at least 30 wt. %; and
connecting the first and the second substrate using the adhesive composition, wherein the adhesive composition is in liquid form; and
cooling the adhesive composition,
wherein the adhesive composition is thermoreversible, wherein the adhesive composition loses its thermoreversibility when the adhesive composition is set by drying.
2. Method according to claim 1 , wherein the aqueous adhesive composition is provided in solidified form and subsequently melted to liquid form.
3. Method according to claim 1 , wherein the adhesive composition is cooled from a temperature of 50° C. or higher to a temperature of 40° C. or lower.
4. Method according to claim 1 , wherein the thermoreversible gelling starch is obtained from an amylose containing starch, which starch has been treated with an enzyme having α-1,4-α-1,4-glucosyl transferase activity.
5. Method according to claim 1 , wherein the thermoreversible gelling starch is obtained by partial debranching of a starch.
6. Method according to claim 5 , wherein the thermoreversible gelling starch is obtained by treating a starch with α-1,6-D-glucanohydrolase.
7. Method according to claim 5 , wherein the thermoreversible gelling starch comprises up to 80 wt. % short chain amylose and at least 20 wt. % partially debranched amylopectin.
8. Method according to claim 1 , wherein the thermoreversible gelling starch comprises 5-95 wt. % of a crosslinked starch and 95-5 wt. % of a degraded starch.
9. Method according to claim 1 , wherein the bonding starch is a degraded starch.
10. Method according to claim 1 , wherein the bonding starch is a low dextrose equivalent maltodextrin having a dextrose equivalent of less than 20.
11. Method according to claim 9 , wherein the bonding starch is derived from starch containing more than 95 wt. % amylopectin, based on the total starch weight.
12. Method according to claim 10 , wherein the bonding starch is derived from starch containing more than 95 wt. % amylopectin, based on the total starch weight.
13. Method according to claim 1 , wherein the plasticizer is a low molecular weight sugar.
14. Method according to claim 13 , wherein the plasticizer is selected from the group consisting of sorbitol, mannitol and sucrose.
15. Method according to claim 1 , wherein the content of the plasticizer in the adhesive composition is 0.1-50 wt. %, based on the total weight of the adhesive composition.
16. Method according to claim 15 , wherein the content of the plasticizer in the adhesive composition is 1-40 wt. %, based on the total weight of the adhesive composition.
17. Method according to claim 16 , wherein the content of the plasticizer in the adhesive composition is 3-30 wt %, based on the total weight of the adhesive composition.
18. Method according to claim 1 , comprising 1-60 wt % thermoreversible gelling starch, based on the total weight of the composition.
19. Method according to claim 18 , comprising 2-40 wt. % thermoreversible gelling starch, based on the total weight of the composition.
20. Method according to claim 19 , comprising 3-35 wt. % thermoreversible gelling starch, based on the total weight of the composition.
21. Method according to claim 1 , comprising 5-80 wt. % bonding starch, based on the total weight of the composition.
22. Method according to claim 21 , comprising 10-75 wt. % bonding starch, based on the total weight of the composition.
23. Method according to claim 22 , comprising 30-70 wt. % bonding starch, based on the total weight of the composition.
24. Method according to claim 1 , comprising 30-80 wt. % water, based on the total weight of the composition.
25. Method according to claim 24 , comprising 30-70 wt. % water based on the total weight of the composition.
26. Method according to claim 1 , wherein the composition is a thermoreversible gel.
27. Method according to claim 1 , wherein the composition is a hotmelt adhesive.
28. Method according to claim 1 , wherein the composition is a drying adhesive.