Amphiphilic additives as compatibilizers for rosin tackifiers in polyolefin hot-melt adhesives

1. A blend consisting of:

a rosin acid or a derivative thereof; and

an amphiphilic agent comprising at least one hydrocarbon chain having an average carbon number of 6 to 50 and a polar functional group, wherein the hydrocarbon chain is linear, branched, or cyclic,

wherein the amphiphilic agent has a melting point above 100° C., a softening point above 100° C., or a combination thereof.

2. A hot-melt adhesive composition comprising the blend of claim 1 and at least one of a polyolefin base polymer, a linear or branched hydrocarbon wax, or a combination thereof.

3. The blend of claim 1 , wherein the polar functional group comprises a hydroxyl group, a carboxylic acid group, a carboxylic ester group, an amide group, or an ethoxylate group.

4. The blend of claim 1 , wherein the rosin acid or derivative thereof is derived from at least one of a gum tree rosin, a wood rosin, a softwood rosin, a hardwood rosin, a natural oil, or a combination thereof.

5. The blend of claim 1 , wherein the rosin acid derivative is a hydrogenated rosin, disproportionated rosin, a maleated rosin, a fumarated rosin, itaconic acid adduct or anhydride adduct, an acrylic acid adduct, a dimer acid, or a combination thereof.

6. The blend of claim 1 , wherein the rosin acid derivative is an ester of a rosin acid.

7. The blend of claim 1 , wherein the rosin acid derivative is a hydrogenated rosin ester, disproportionated rosin ester, a maleated rosin ester, a fumarated rosin ester, an ester of an itaconic acid adduct, an itaconic anhydride adduct, an ester of an acrylic acid adduct, an ester of a dimer acid, or a combination thereof.

8. The blend of claim 6 , wherein the ester of the rosin acid is derived from palmityl alcohol, stearyl alcohol, abietyl alcohol, polyethylene monoalcohol, hydroxyl-terminated polybutadiene, ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerol, sorbitan, isosorbide, pentaerythritol, dipentaerythritol, tripentaerythritol, polypentaerythritol, or any combination thereof.

9. A hot-melt adhesive composition comprising the blend of claim 1 and a polyolefin base polymer prepared using a metallocene-catalyzed process.

10. A hot-melt adhesive composition comprising the blend of claim 1 and a polyolefin base polymer comprising a copolymer derived from ethylene and an alpha-olefin.

11. A hot-melt adhesive composition comprising the blend of claim 1 and a polyolefin base polymer that is an elastomer.

12. The blend of claim 1 , wherein:

the amphiphilic agent is present in an amount of about 5 to about 30 wt %, based on the total weight of the blend, and the amphiphilic agent is palmityl alcohol, stearyl alcohol, or a combination thereof; and

the rosin acid derivative is a rosin ester.

13. The blend of claim 1 , wherein:

the amphiphilic agent is (i) stearyl alcohol that is present in an amount greater than about 5 to about 15 wt %, based on the total weight of the blend, or (ii) palmityl alcohol that is present in an amount greater than about 10 to about 25 wt %, based on the total weight of the blend; and

the rosin acid derivative is an ester of a maleated adduct of a rosin acid.

14. The blend of claim 1 , wherein:

the rosin acid derivative is present in an amount of about 60 to about 80 wt %, based on the total weight of the blend, and the rosin acid derivative a pentaerythritol ester of a rosin acid; and

the amphiphilic agent is present in an amount of about 20 to about 40 wt %, based on the total weight of the blend.

15. The blend of claim 1 , wherein the amphiphilic agent is an alcohol, a fatty acid, a dimer acid, a fatty amide, a fatty aldehyde, a fatty ester, rosin alcohol, rosin ester, rosin amide, or a combination thereof.

16. The blend of claim 1 , wherein the amphiphilic agent is palmityl alcohol, stearyl alcohol, octadecanol, abietyl alcohol, a polyethylene monoalcohol, ethylene (bis) stearate, a polyethylene alcohol, or a combination thereof.

17. The hot-melt adhesive composition of claim 2 , wherein the composition is substantially free of a tackifying agent different from the rosin acid or derivative thereof.

18. The blend of claim 1 , wherein the rosin acid derivative is a pentaerythritol ester of a maleated rosin acid and the amphiphilic agent is palmityl alcohol, stearyl alcohol, or a combination thereof, that is present in an amount greater than about 10 to about 25 wt %, based on the total weight of the blend.

19. The blend of claim 1 , wherein:

the rosin acid derivative is a glycerol ester of a rosin acid; and

the amphiphilic agent is present in an amount of up to about 20 wt %, based on the total weight of the blend, and the amphiphilic agent is ethylene (bis-stearate).

20. The blend of claim 1 , wherein:

the rosin acid derivative is a glycerol ester of a rosin acid; and

the amphiphilic agent is present in an amount of greater than about 5 wt %, based on the total weight of the blend, and the amphiphilic agent is ethylene (bis-stearate), stearyl alcohol palmityl alcohol, or a combination thereof.

21. The blend of claim 1 , wherein:

the rosin acid derivative is present in an amount of about 60 to about 80 wt %, based on the total weight of the blend, and the rosin acid derivative is a rosin ester; or

the amphiphilic agent is present in an amount of about 40 to about 60 wt %, based on the total weight of the blend.

22. A hot-melt adhesive composition comprising:

about 35 to about 55 wt % of a polyolefin elastomer,

about 10 to about 30 wt % of a hydrocarbon wax, and

about 35 to about 65 wt % of the blend of claim 1 , wherein:

the amphiphilic agent is present in an amount of about 10 to about 40 wt %, based on the total weight of the blend, and

the rosin acid or derivative thereof is a rosin ester that is present in an amount of about 60 to about 90 wt %, based on the total weight of the blend of a rosin ester.