US 12,291,627 B2
Propylene-based terpolymer composition for pipes
Henrica Norberta Alberta Maria Steenbakkers-Menting, Geleen (NL); Tinashe Victor Mandishonha Ndoro, Geleen (NL); Desiree Marie Louise Seegers, Geleen (NL); Erik Delsman, Geleen (NL); Raymond Gerlofsma, Geleen (NL); Tim Kiggen, Geleen (NL); Martin Alexander Zuideveld, Geleen (NL); Akhlaq Moman, Geleen (NL); and Patrick Elisabeth Luc Voets, Geleen (NL)
Assigned to SABIC GLOBAL TECHNOLOGIES B.V., Bergen op Zoom (NL)
Appl. No. 17/263,338
Filed by SABIC GLOBAL TECHNOLOGIES B.V., Bergen op Zoom (NL)
PCT Filed Jul. 22, 2019, PCT No. PCT/EP2019/069640
§ 371(c)(1), (2) Date Jan. 26, 2021,
PCT Pub. No. WO2020/020811, PCT Pub. Date Jan. 30, 2020.
Claims priority of application No. 18185950 (EP), filed on Jul. 27, 2018.
Prior Publication US 2021/0214540 A1, Jul. 15, 2021
Int. Cl. C08L 23/12 (2006.01); G01N 33/44 (2006.01)
CPC C08L 23/12 (2013.01) [G01N 33/442 (2013.01); C08L 2203/18 (2013.01)] 18 Claims
 
1. A polypropylene composition comprising a terpolymer composition comprising (A) a first terpolymer fraction containing propylene, ethylene and 1-hexene, wherein the first terpolymer fraction has a melt flow rate of 0.030 to 1.0 dg/min determined by ISO 1133-1:2011 (230° C., 5 kg) and (B) a second terpolymer fraction containing propylene, ethylene and 1-hexene, wherein the second terpolymer fraction has a melt flow rate of 0.30 to 70 dg/min determined by ISO 1133-1:2011 (230° C., 2.16 kg),
wherein the first terpolymer fraction is prepared using a first set of reaction conditions, the second terpolymer fraction is prepared using a second set of reaction conditions and the first and second set of reaction conditions are different, wherein the polypropylene composition
(i) has a melt flow rate of 0.10 to 0.70 dg/min determined by ISO 1133-1:2011 (230° C., 2.16 kg);
(ii) has a content of ethylene derived units in the range from 1.6 to 3.5 wt %;
(iii) has a content of 1-hexene derived units in the range from 1.7 to 4.0 wt %;
wherein the content of ethylene derived units in the polypropylene composition in wt % is larger than the content of 1-hexene derived units in the polypropylene composition in wt %-0.10 wt %; and
wherein the composition has <Gp>/Y of at least 7.5, wherein <Gp> is strain hardening modulus and Y is yield stress and <Gp>/Y is determined by:
a) providing a specimen of the composition by compression molding a sheet from the composition according to ISO 1873-2 to a thickness of 0.3 mm±0.025 mm and punching a specimen having a geometry of the test specimen described in ISO/DIS 18488 from the sheet, wherein the sheet is annealed after the compression molding and before the punching at a temperature of 100° C. for 1 hour and cooled down to room temperature,
b) elongating the specimen at a constant traverse speed of 20 mm/min at 100° C.
c) measuring the load sustained by the specimen during the elongation to obtain a stress-strain curve and measuring the yield stress Y,
d) calculating true stress-true strain curve from the stress strain curve obtained by step c) and calculating the tensile strain hardening modulus <Gp> from the true stress-strain curve, according to the method as described in ISO/DIS 18488 and
e) calculating a quotient of the tensile strain hardening modulus <Gp> divided by the yield stress Y.