Patent ID: 11873388
Assignee: OMYA INTERNATIONAL AG
Field: Surface technology, coating (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 14:
15. A process for producing a mono or multi-layer polyester film as defined in claim 1, the process comprising the steps of:
a) providing a composition comprising at least one polyester and a surface-treated filler material product, and
b) forming a film from the composition of step a), wherein the surface-treated filler material product comprises
A) at least one ground calcium carbonate-comprising filler material having a weight median particle size d50 in the range from 0.5 μm to 3.0 μm, and
B) a treatment layer on the surface of the at least one ground calcium carbonate-comprising filler material comprising
i. at least one aliphatic aldehyde and/or salty reaction products thereof, and/or
ii. at least one mono-substituted succinic anhydride consisting of succinic anhydride mono-substituted with a group selected from a linear, branched, aliphatic and cyclic group having a total amount of carbon atoms from at least C2 to C30 in the substituent and/or salty reaction products thereof, and/or
iii. at least one polydialkylsiloxane, and/or
iv. mixtures of the materials according to i. to iii., wherein the surface-treated filler material product comprises the treatment layer in an amount of from 0.1 to 2.3 wt.-%, based on the total dry weight of the at least one ground calcium carbonate-comprising filler material.