Oriented multilayer polyolefin films
First Claim
1. A film comprising at least one primary layer and at least one secondary layer, wherein the primary layer comprises a propylene-containing polymer having a first melting point and the secondary layer comprises a propylene-containing polymer having a second melting point, wherein the second melting point is greater than the first melting point and the multi-layered construction is biaxially stretched, such that that the stretched film exhibits a difference in birefringence wherein Δ
-
n≧
−
3×
10−
3.
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Accused Products
Abstract
A multi-layered biaxially oriented film comprising at least one primary layer and at least one secondary layer, wherein the primary layer comprises a propylene copolymer having a first melting point and the secondary layer comprises a polypropylene homopolymer or copolymer having a second melting point, such that the second melting point is greater than the first melting point and the multi-layered construction is biaxially stretched. The multi-layered film further includes a surface finishing layer, to provide a writable multi-layered film. This stretched film exhibits a refractive index in the machine direction (MD) that is greater than the refractive index measured in the transverse direction (TD).
25 Citations
69 Claims
- 1. A film comprising at least one primary layer and at least one secondary layer, wherein the primary layer comprises a propylene-containing polymer having a first melting point and the secondary layer comprises a propylene-containing polymer having a second melting point, wherein the second melting point is greater than the first melting point and the multi-layered construction is biaxially stretched, such that that the stretched film exhibits a difference in birefringence wherein Δ
-
15. A film comprising at least one primary layer and at least one secondary layer, wherein the primary layer comprises a propylene copolymer having a first melting point and the secondary layer comprises a polypropylene homopolymer or copolymer having a second melting point and the second melting point is greater than the first melting point and the multi-layered construction is biaxially stretched, such that a single azimuthal scan maximum of the stretched film is within ±
- 75°
with respect to the MD, as measured by WAXS transmission azimuthal scan. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
- 75°
-
30. A film comprising at least one primary layer and at least one secondary layer, wherein the primary layer comprises a propylene copolymer having a first melting point and the secondary layer comprises a polypropylene homopolymer or copolymer having a second melting point and the second melting point is greater than the first melting point and the multi-layered construction is biaxially stretched, such that the stretched film exhibits a refractive index in the machine direction (MD) that is greater than the refractive index measured in the transverse direction (TD) and a single azimuthal scan maximum of the stretched film is within ±
- 75°
with respect to the MD, as measured by WAXS transmission azimuthal scan. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
- 75°
-
45. A film comprising:
-
at least one primary layer and at least one secondary layer, wherein the primary layer comprises a major component of a propylene-containing polymer having a first melting point and the secondary layer comprises a major component having a second melting point, the second melting point being greater than the first melting point;
wherein the multi-layered construction has been biaxially oriented so as to provide a crystalline orientation as determined by wide angle X-ray scattering (WAXS) measurements from the monoclinic (110) crystalline planes that is isotropic or exhibits at most a single specific azimuthal scan maximum, said maximum being positioned at an angle of up to ±
75°
from the machine direction (MD). The single azimuthal scan maximum in addition possesses an angular full width at half peak height (FWHM) between about 40°
to 75°
;
wherein said film has an energy to puncture parallel to the reference or MD of up to about 20 J/cm2. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59)
-
-
60. An adhesive tape backing comprising:
-
at least one primary layer and at least one secondary layer, wherein said multi-layered construction has been biaxially oriented so as to provide a crystalline orientation as determined by wide angle X-ray scattering (WAXS) measurements from the monoclinic (110) crystalline planes that is isotropic or exhibits at most a single specific azimuthal scan maximum, said maximum being positioned at an angle of up to ±
75°
from the machine direction (MD), and said maximum in addition possesses an angular full width at half peak height (FWHM) between about 40°
to 75°
;
wherein said film has an energy to puncture parallel to the reference or MD of up to about 20 J/cm2 and a transmittance haze value up to about 2%.
-
-
61. An adhesive tape backing comprising:
-
at least one primary layer and at least one secondary layer, wherein the primary layer comprises a major component having a propylene-containing polymer having a first melting point and the secondary layer comprises a major component having a second melting point, the second melting point being greater than the first melting point;
wherein said multi-layered construction has been biaxially oriented so as to provide a crystalline orientation as determined by wide angle X-ray scattering (WAXS) measurements from the monoclinic (110) crystalline planes that is isotropic or exhibits at most a single specific azimuthal scan maximum, said maximum being positioned at an angle of up to ±
75°
from the machine direction (MD). The single azimuthal scan maximum in addition possesses an angular full width at half peak height (FWHM) between about 40°
to 75°
;
wherein said adhesive tape backing exibits a birefringence calculated by subtracting the refractive index measured in the transverse direction from that measured in the machine direction of at least about −
3×
10−
3; and
in which the primary layer polymer has an initial melt flow rate of up to 25 g/10 min.
-
-
62. An adhesive tape backing comprising:
-
at least one primary layer and at least one secondary layer, wherein said multi-layered construction has been biaxially oriented so as to provide a crystalline orientation as determined by wide angle X-ray scattering (WAXS) measurements from the monoclinic (110) crystalline planes that is isotropic or exhibits at most a single specific azimuthal scan maximum, said maximum being positioned at an angle of up to ±
75°
from the machine direction (MD), and said maximum in addition possesses an angular full width at half peak height (FWHM) between about 40°
to 75°
;
wherein said film has an energy to puncture parallel to the reference or MD of up to about 10 J/cm2 and a transmittance haze up to about 1%.
-
-
63. An adhesive coated article comprising:
-
(a) a multilayered biaxially stretched film comprising, (i) at least one primary layer, wherein the primary layer comrpises a propylene-containing polymer having a first melting point;
(ii) at least one secondary layer, wherein the secondary layer comprises a propylene-containing polymer having a second melting point, such that the second melting point is greater than the first melting point; and
(b) at least one adhesive coated layer coated on one surface of the multilayered biaxially stretched film. - View Dependent Claims (64, 65, 66, 67, 68, 69)
-
Specification