Filled epsilon-caprolactone based polymer compositions, method for preparing same and articles based on said compositions
Compositions based on ε-caprolactone polymer, comprising at least one ε-caprolactone polymer and calcium carbonate. Process for preparing these compositions, which are used for manufacturing articles, in particular films, preferably obtained by extrusion blow-moulding or by flat-die extrusion.
1. A composition comprising:
at least one ε-caprolactone polymer and
calcium carbonate in the form of coated particles,
wherein the coating represents less than 3% by weight of the calcium carbonate particles.
2. The composition of claim 1 , which comprises only ε-caprolactone homopolymers and does not comprise copolymers of ε-caprolactone with other monomers.
3. The composition of claim 1 , which comprises at least one ε-caprolactone unbranched homopolymers.
4. The composition of claim 1 , which comprises at least one ε-caprolactone branched homopolymers.
5. The composition of claim 1 , which comprises at least one copolymers of ε-caprolactone with another monomers.
6. The composition of claim 1 , which comprises at least 25% by weight of calcium carbonate.
7. The composition of claim 1 , which comprises 30 to 50% by weight calcium carbonate.
8. The composition of claim 1 , wherein said calcium carbonate particles have a mean diameter of less than 5 μm.
9. The composition of claim 1 , wherein said calcium carbonate particles have a mean diameter of less than 3 μm.
10. The composition of claim 1 , wherein said calcium carbonate particles have a mean diameter of less than 1 μm.
11. The composition of claim 1 , wherein the fraction of the calcium carbonate particles with a diameter of greater than 10 μm is less than 3% by volume.
12. The composition of claim 1 , wherein the calcium carbonate particles have a high cutoff of less than 12 μm.
13. The composition of claim 1 , wherein the calcium carbonate is of natural origin and is obtained from ground marble.
14. The composition of claim 1 , wherein the calcium carbonate contains less than 0.5% moisture.
15. The composition of claim 1 , wherein the coating comprises one or more saturated fatty acids with a chain of 8 to 26 carbon atoms.
16. The composition of claim 1 , wherein the coating comprises one or more unsaturated fatty acids with a chain of 8 to 26 carbon atoms.
17. The composition of claim 1 , wherein said calcium carbonate particles comprise fatty acids bound to the calcium carbonate particles and fatty acids not bound to the calcium carbonate particles.
18. The composition of claim 17 , wherein the proportion of fatty acids not bound to the calcium carbonate particles is less than 0.5% by weight relative to the weight of calcium carbonate.
19. A process for preparing the composition of claim 1 , wherein at least one E-caprolactone polymer and calcium carbonate are melt-blended in an extruder.
20. An article comprising the composition of claim 1 .
21. An article obtained by extruding the composition of claim 1 .
22. The article of claim 20 which is selected from the group consisting of a foam, bottle, plaque and sheet.
23. The article of claim 20 which is film.
24. The film of claim 23 which is obtained by extrusion blow-molding or by flat-die extrusion.
25. The article of claim 20 , which has an impact strength, determined according to ISO standard 7765-1 A (1988), which is better than that of a similar article obtained by the same processing technique using a composition of identical reference, but free of calcium carbonate.