Unoriented film

Patent metadata

Field	Value
Publication number	US-9840616-B2
Application number	US-201214232201-A
Country	US
Kind code	B2
Filing date	Jul 10, 2012
Priority date	Jul 15, 2011
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

Unoriented film comprising at least 70 wt.-% of an heterophasic propylene copolymer, said heterophasic propylene copolymer comprises a matrix being a random propylene copolymer and an elastomeric propylene copolymer dispersed in said matrix, wherein the heterophasic propylene copolymer has (a) a melt flow rate MFR 2 (230° C.) in the range of 3.0 to 10.0 g/10 min, (b) a melting temperature in the range of 130 to 150° C., (c) a xylene cold soluble content in the range of 25 to 50 wt.-%, (d) comonomer content in the range of 10.0 to 15.0 wt.-%, wherein further the xylene cold soluble content of the heterophasic propylene copolymer has (e) a comonomer content in the range of 20 to 30 wt.-% and (f) an intrinsic viscosity in the range of 0.8 to below 2.0 dl/g.

First claim

The invention claimed is:

1. Unoriented film comprising at least 70 wt.% of an heterophasic propylene copolymer (RAHECO), said heterophasic propylene copolymer (RAHECO) comprises a matrix (M) being a random propylene copolymer (R-PP) and an elastomeric propylene copolymer (E) dispersed in said matrix (M), wherein the heterophasic propylene copolymer (RAHECO) has:
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 3.0 to 10.0 g/10 min,
(b) a melting temperature Tm determined by differential scanning calorimetry (DSC) in the range of 130 to 150° C.,
(c) a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) in the range of 25 to 50 wt. %,
(d) a comonomer content in the range of 10.0 to 13.5 wt. %,
wherein the xylene cold soluble content (XCS) of the heterophasic propylene copolymer (RAHECO) has:
(e) a comonomer content in the range of 21.6 to 30 wt.% and
(f) an intrinsic viscosity (IV) determined according to DIN ISO 1628/1, (in Decalin at 135 ° C.) in the range of 0.8 to below 2.0 dl/g, and
wherein the random propylene copolymer (R-PP):
(g) has a comonomer content in the range of 7.1 to 9.0 wt.%, and
(h) comprises at least two propylene copolymer fractions (R-PP1) and (R-PP2), wherein the first propylene copolymer fraction (R-PP1) has a comonomer content in the range of 2.0 to 6.0 wt %, and the second propylene copolymer fraction (R-PP2) has a comonomer content in the range of 8.0 to 11.0 wt.%,
wherein the comonomer content of the elastomeric propylene copolymer (E) is in the range of 30.0 to 36.0 wt. %, and
wherein said film has a thickness of 5 to 2,000 μm.

2. Unoriented film according to claim 1 , wherein
[R-PP]−[R-PP1]≧2.5, wherein
[R-PP] is the comonomer content [wt. %] of the random propylene copolymer (R-PP), and [R-PP1] is the comonomer content [wt. %] of the first propylene copolymer fraction (R-PP1).

3. Unoriented film according to claim 1 , wherein the comonomers of the random propylene copolymer (R-PP), the first propylene copolymer fraction (R-PP1) and the second propylene copolymer fraction (R-PP2) are ethylene and/or C 4 to C 12 α-olefin.

4. Unoriented film according to claim 1 , wherein said film has:
(a) a tensile modulus in machine direction measured on a cast film with a thickness of 130 μm according to ISO 527-3 at 23° C. and a cross head speed of 1 mm/min in the range of 100 to 250 MPa, and/or
(b) a relative total penetration energy (Wbreak) as determined by the “Dynatest” method according to ISO 7725-2 at 0° C. on a cast film with a thickness of 130 μm in the range of 10 to 50 J/mm.

5. Unoriented film according to claim 1 , wherein said film has:
(a) a transparency of at least 90%,
(b) a haze of below 6.0%, and/or
(c) a clarity of at least 92%, measured on a 50 μm cast film according to ASTM D1003-00.

6. Unoriented film according to claim 1 , wherein said film has a hexane soluble content determined according to FDA (section 177.1520) on a 100 μm cast film of below 8.0 wt. %.

7. Unoriented film according to claim 1 , wherein the heterophasic propylene copolymer (RAHECO) has been visbroken.

8. Unoriented film according to claim 7 , wherein the heterophasic propylene copolymer (RAHECO) prior to visbreaking is a heterophasic propylene copolymer (Pre-RAHECO) comprising a matrix (Pre-M) being a random propylene copolymer (Pre-R-PP) and an elastomeric propylene copolymer (Pre-E) dispersed in said matrix (Pre-M), said heterophasic propylene copolymer (Pre-RAHECO) has:
(a) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 0.3 to 2.5 g/10 min, and
(b) a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) in the range of 25 to 50 wt. %,
wherein further the xylene cold soluble content (XCS) of the heterophasic propylene copolymer (Pre-RAHECO) prior to visbreaking has an intrinsic viscosity (IV) determined according to DIN ISO 1628/1, (in Decalin at 135° C.) in the range of 1.4 to below 2.5 dl/g.

9. Unoriented film according to claim 1 , wherein the unoriented film is a cast film or a blown film.

10. Process for producing an unoriented film according to claim 1 , comprising the steps of:
(a) producing in a multistage process comprising at least two reactors connected in series a heterophasic propylene copolymer (Pre-RAHECO) comprising a matrix (Pre-M) being a random propylene copolymer (Pre-R-PP) and an elastomeric propylene copolymer (Pre-E) dispersed in said matrix (Pre-M), wherein said heterophasic propylene copolymer (Pre-RAHECO) has:
(a1) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 0.3 to 2.5 g/10 min, and
(a2) a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) in the range of 25 to 50 wt. %,

wherein further the xylene cold soluble content (XCS) of said heterophasic propylene copolymer (Pre-RAHECO) has an intrinsic viscosity (IV) determined according to DIN ISO 1628/1, (in Decalin at 135° C.) in the range of 1.4 to below 2.5 dl/g,
(b) visbreaking the heterophasic propylene copolymer (Pre-RAHECO) of step (a) obtaining a heterophasic propylene copolymer (RAHECO), said heterophasic propylene copolymer (RAHECO) has:
(b1) a melt flow rate MFR 2 (230° C.) measured according to ISO 1133 in the range of 3.0 to 10.0 g/10 min,
(b2) a melting temperature Tm determined by differential scanning calorimetry (DSC) in the range of 130 to 150° C.,
(b3) a xylene cold soluble content (XCS) determined according ISO 16152 (25° C.) in the range of 25 to 50 wt. %, and
(b4) a comonomer content in the range of 10.0 to 13.5 wt. %,

wherein the xylene cold soluble content (XCS) of the heterophasic propylene copolymer (RAHECO) of step (b) has:
(b5) a comonomer content in the range of 21.6 to 30 wt.% and
(b6) an intrinsic viscosity (IV) determined according to DIN ISO 1628/1, (in Decalin at 135° C.) in the range of 0.8 to below 2.0 dl/g,

wherein the random propylene copolymer (R-PP):
(b7) has a comonomer content in the range of 7.1 to 9.0 wt.%, and
(b8) comprises at least two propylene copolymer fractions (R-PP1) and (R-PP2), wherein the first propylene copolymer fraction (R-PP1) has a comonomer content in the range of 2.0 to 6.0 wt %, and the second propylene copolymer fraction (R-PP2) has a comonomer content in the range of 8.0 to 11.0 wt. % and

wherein the comonomer content of the elastomeric propylene copolymer (E) is in the range of 30.0 to 36.0 wt. %; and
(c) extruding said heterophasic propylene copolymer (RAHECO) of step (b) into a unoriented film.

11. Process according to claim 10 , wherein:
(a) in a first reactor propylene and ethylene and/or C 4 to C 12 α-olefin are polymerized obtaining a first propylene copolymer fraction (Pre-PP1),
(b) transferring said first propylene copolymer fraction (Pre-PP1) in a second reactor,
(c) polymerizing in said second reactor in the presence of the first propylene copolymer fraction (Pre-PP1) propylene and ethylene and/or C 4 to C 12 α-olefin obtaining a second propylene copolymer fraction (Pre-PP2), said first propylene copolymer fraction (Pre-PP1) and said second propylene copolymer fraction (Pre-PP2) form the matrix (Pre-PP),
(d) transferring said matrix (Pre-M) in a third reactor, and
(e) polymerizing in said third reactor in the presence of the matrix (Pre-M) propylene and ethylene and/or C 4 to C 12 α-olefin obtaining an elastomeric propylene copolymer (E), said matrix (Pre-M) and said elastomeric propylene copolymer (E) form the heterophasic propylene copolymer (Pre-RAHECO).

12. Process according to claim 11 , wherein unoriented film and/or the heterophasic propylene copolymer (RAHECO) has:
(a) a m

Assignees

• Gahleitner Markus
• Sandholzer Martina
• Bernreitner Klaus
• Leskinen Pauli
• Borealis Ag

Inventors

• Gahleitner Markus
• Sandholzer Martina
• Bernreitner Klaus
• Leskinen Pauli

Classifications

• C08F210/06 Primary

  Propene · CPC title

• C08F2/001

  Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence) · CPC title

• C08F210/16

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08J2323/14

  Copolymers of propene (C08J2323/16 takes precedence) · CPC title

• C08L2666/06

  Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof · CPC title