	US 12,226,933 B2
	Polyethylene blend
Tuan Anh Tran, Linz (AT); Susana Lopes Filipe, Evora (PT); Andreas Nagl, Linz (AT); and Doris Machl, Linz (AT)
Assigned to Borealis AG, Vienna (AT)
Appl. No. 18/563,983
Filed by Borealis AG, Vienna (AT)
PCT Filed May 31, 2022, PCT No. PCT/EP2022/064702 § 371(c)(1), (2) Date Nov. 24, 2023, PCT Pub. No. WO2022/253804, PCT Pub. Date Dec. 8, 2022.
Claims priority of application No. 21176834 (EP), filed on May 31, 2021.
Prior Publication US 2024/0262012 A1, Aug. 8, 2024
Int. Cl. B29B 17/02 (2006.01); B29B 9/12 (2006.01); B29B 17/04 (2006.01); B29K 23/00 (2006.01); B29K 105/00 (2006.01); B29K 105/06 (2006.01); B29K 105/26 (2006.01)

CPC B29B 17/02 (2013.01) [B29B 9/12 (2013.01); B29B 17/0412 (2013.01); B29B 2017/0203 (2013.01); B29B 2017/0224 (2013.01); B29K 2023/06 (2013.01); B29K 2023/065 (2013.01); B29K 2105/0085 (2013.01); B29K 2105/0094 (2013.01); B29K 2105/065 (2013.01); B29K 2105/251 (2013.01); B29K 2105/26 (2013.01); B29K 2995/0018 (2013.01); B29K 2995/0063 (2013.01); B29K 2995/0077 (2013.01); B29K 2995/0078 (2013.01)]

15 Claims

1. A polyethylene blend having

(i) a melt flow rate (ISO1133, 5.0 kg; 190° C.) of 0.1 to 10 g/10 min; and

(ii) a density of 950 to 970 kg/m³(ISO1183); and

(iii) a C2 fraction in an amount of above 95.0 wt.-% as measured by NMR of the d2-tetrachloroethylene soluble fraction; and

(iv) a homopolymer fraction (HPF) content determined according to Chemical Composition Analysis by Cross Fractionation Chromatography (CFC) in the range from 80.0 to 91.0 wt.-%; and

(v) a copolymer fraction (CPF) content determined according to Chemical Composition Analysis Cross Fractionation Chromatography (CFC) in the range from 9.0 to 20.0 wt.-%; and

(vi) optionally an iso-PP fraction (IPPF) content determined according to Chemical Composition Analysis Cross Fractionation Chromatography (CFC) in the range from 0 to 2.0 wt.-%, wherein the iso-PP fraction (IPPF) is defined as the polymer fraction eluting at a temperature of 104° C. and above, wherein the homopolymer fraction (HPF), said copolymer fraction (CPF), and said iso-PP fraction (IPPF) add up to 100 wt.-%; and

(vii) inorganic residues (measured by TGA) of 0.01 to 2.00 wt.-% with respect to the total polyethylene blend; and

(viii) OCS gels of size 100 to 299 micrometer measured on 10 m²of film by an OCS count instrument within the range of 500 to 5000 counts per squaremeter; and

wherein

(ix) the polyethylene blend has a CIELAB color space (L*a*b*) measured according to DIN EN ISO 11664-4 of

L* from 75.0 to 86.0;

a* from −5.0 to 0.0;

b* from 5.0 to below 25.0

(x) the polyethylene blend has a CIELAB color space (L*a*b*) measured according to DIN EN ISO 11664-4 of

L* from above 86.0 to 97.0;

a* from −5.0 to 0.0;

b* from 0.0 to below 5.0;

wherein the polyethylene blend is a recycled material obtainable from the following steps

a) providing post-consumer plastic trash;

b) sorting out goods made from polystyrene, polyamide, polypropylene, metals, paper and wood thereby providing a post-consumer plastic material;

c) sorting out colored goods thereby providing a first intermediate stream of essentially colorless articles and a second intermediate stream of articles having essentially white color;

d) optionally sorting out impurities by manual inspection;

e) wherein receiving two streams of polyethylene material, a first stream being essentially transparent and a second stream being essentially of white color;

f) subjecting both streams separately to milling, washing in an aqueous solution with various detergents and subsequent drying, windsifting and screening yielding two pretreated streams;

g) subjecting the two pretreated streams separately to a further sorting for eliminating non-polyolefin and colored parts;

h) extruding into pellets;

i) optionally aerating at a temperature in a range of 100-130° C.