Highly filled soft polyolefin composition for roofing membrane

Patent metadata

Field	Value
Publication number	US-2016257809-A1
Application number	US-201415029470-A
Country	US
Kind code	A1
Filing date	Oct 1, 2014
Priority date	Oct 15, 2013
Publication date	Sep 8, 2016
Grant date	—

Abstract

The present disclosure relates to highly filled polyolefin compositions with improved balance of properties particularly for applications where puncture and tear resistance is requested comprising a flexible heterophasic polyolefin composition (I), consisting of a crystalline polymer fraction (A) consisting of a copolymer of propylene with ethylene having a fraction insoluble in xylene at 25° C. of at least 90% by weight, and an elastomeric fraction (B) consisting of a copolymer or blend of copolymers of ethylene with propylene; the copolymer or blend containing units derived from ethylene in a quantity lower than 40% by weight. The fraction soluble in xylene at 25° C. of the polyolefin composition having an IV gpc lower than 2.5 dl/g, a broad molecular weight distribution Mw/Mn (GPC) equal to or higher than 4, and a Mz/Mw (GPC) equal to or higher than 2.5. The filled polyolefin composition further comprises inorganic filler (II) and a butene-1 copolymer having: a flexural modulus (ISO 178) lower than 60 MPa, a Shore A (ISO 868) lower than 90 and a Tg (DMTA) lower than −20° C.

First claim

What is claimed is:

1 . A filled polyolefin composition having a MFR (230° C./2.16 kg) of from 2 to 7/10 min comprising:
a) 35 to 65% by weight of a flexible heterophasic polyolefin composition (I), comprising the following fractions:
A) from greater than 40 to 55% by weight of a crystalline polymer fraction consisting of a copolymer of propylene with ethylene; the copolymer containing at least 85% by weight of units derived from propylene, and the crystalline fraction having a fraction insoluble in xylene at 25° C. of at least 90% by weight;
B) from 45 to less than 60% by weight of an elastomeric fraction consisting of a copolymer or blend of copolymers of ethylene with propylene; the copolymer or blend containing units derived from ethylene in a quantity lower than 40% by weight; and
the fraction soluble in xylene at 25° C. of the polyolefin composition (I) having an IVgpc lower than 2.5 dl/g, a broad molecular weight distribution Mw/Mn (GPC) equal to or higher than 4, and a Mz/Mw (GPC) equal to or higher than 2.5;

b) 30 to 80% by weight of an inorganic filler (II) selected from flame-retardant inorganic fillers and inorganic oxides or salts; and
c) 2 to 25% by weight of a butene-1 copolymer having a flexural modulus (ISO 178) lower than 60 MPa, a Shore A (ISO 868) lower than 90 and a Tg (DMTA) lower than −20° C.;
wherein the sum of a), b) and c) is 100%.

2 . The filled polyolefin composition of claim 1 , wherein the elastomeric fraction B of component (a) has a solubility in xylene at room temperature of greater than 50% by weight.

3 . The filled polyolefin composition of claim 1 , having MFR 230° C./2.16 Kg of from 3 to 8 gr/10 min.

4 . The filled polyolefin composition of claim 1 , wherein the inorganic filler (II) is a flame-retardant inorganic filler selected from hydroxides, hydrated oxides, salts and hydrated salts of metals.

5 . The filled polyolefin composition of claim 1 , wherein component c) is a butene-1 copolymer having:
a content of butene-1 derived units of 80% by weight or more; and a melting temperature DSC (TmI) lower than 110° C.

6 . The filled polyolefin composition of claim 1 , having a Shore D hardness lower than 50, an elongation at break higher than 250%, and tensile strength at break equal to or higher than 10 MPa.

7 . An article comprising the polyolefin composition of claim 1 .

8 . A sheet or film for roofing comprising the polyolefin composition of claim 1 .

9 . An inner filling for industrial cables or cable sheathing comprising polyolefin composition of claim 1 .

Assignees

• Basell Poliolefine Italia Srl
• Via Soperga N 14/A

Inventors

• Biondini Gisella
• Grazzi Michele
• Lunghi Luca
• Cavalieri Claudio

Classifications

• E04D5/06

  by making use of plastics · CPC title

• C08L2201/02

  Flame or fire retardant/resistant · CPC title

• C08L2207/02

  Heterophasic composition · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• H01B3/441

  from alkenes · CPC title