	US 11,746,196 B2
	Calcium carbonate as cavitation agent for biaxially oriented polypropylene films
Martin Brunner, Wallbach (CH); Christoph Hirsiger, Koppigen (CH); Pierre Blanchard, Reyrieux (FR); and Christophe René Pierre Roux, Lyons (FR)
Assigned to Omya International AG, Oftringen (CH)
Appl. No. 16/306,268
Filed by Omya International AG, Oftringen (CH)
PCT Filed Jul. 17, 2017, PCT No. PCT/EP2017/068023 § 371(c)(1), (2) Date Nov. 30, 2018, PCT Pub. No. WO2018/015341, PCT Pub. Date Jan. 25, 2018.
Claims priority of application No. 16180663 (EP), filed on Jul. 21, 2016.
Prior Publication US 2019/0218352 A1, Jul. 18, 2019
Int. Cl. C08J 5/18 (2006.01); C08K 3/26 (2006.01); C08K 9/04 (2006.01); B32B 27/20 (2006.01); B29C 48/08 (2019.01); B29C 48/00 (2019.01); C08F 110/06 (2006.01); C08J 3/22 (2006.01); C08K 9/08 (2006.01); B29K 23/00 (2006.01); B29K 105/04 (2006.01); B29K 105/16 (2006.01); B29K 509/00 (2006.01)

CPC C08J 5/18 (2013.01) [B29C 48/0018 (2019.02); B29C 48/08 (2019.02); B32B 27/205 (2013.01); C08F 110/06 (2013.01); C08J 3/226 (2013.01); C08K 3/26 (2013.01); C08K 9/04 (2013.01); B29K 2023/12 (2013.01); B29K 2105/041 (2013.01); B29K 2105/16 (2013.01); B29K 2509/00 (2013.01); C08J 2323/12 (2013.01); C08K 9/08 (2013.01); C08K 2003/265 (2013.01); C08K 2201/003 (2013.01); C08K 2201/005 (2013.01); C08K 2201/006 (2013.01)]

23 Claims

1. A mono or multi-layer biaxially oriented polypropylene film,

wherein at least one layer of the film comprises at least one polypropylene in an amount ranging from 79.0 to 95.0 wt.-% and at least one natural calcium carbonate in an amount ranging from 5.0 to 21.0 wt.-%, based on the total weight of the layer,

wherein the at least one natural calcium carbonate has a weight median particle size d₅₀from 3.2 μm to 8.0 μm and the at least one natural calcium carbonate is marble and/or limestone and/or chalk, and

wherein the at least one polypropylene and at least one natural calcium carbonate comprising layer of the film, has a density of <0.62 g/cm³.