Compositions of ethylene/α-olefin multi-block interpolymer for blown films with high hot tack
First Claim
Patent Images
1. A composition exhibiting high hot tack comprising at least one ethylene/α
- -olefin multi-block interpolymer, wherein the ethylene/α
-olefin interpolymer comprises at least 60 mole percent ethylene and;
(a) has a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship;
Tm>
−
2002.9 +4538.5(d)−
2422.2(d)2;
or(b) has a Mw/Mn from about 1.7 to about 3.5, and is characterized by a heat of fusion, Δ
H in J/g, and a delta quantity, Δ
T, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of Δ
T and Δ
H have the following relationships;
Δ
T>
−
0.1299(Δ
H)+62.81 for Δ
H greater than zero and up to 130 J/g,
Δ
T≧
48°
C. for Δ
H greater than 130 J/g,wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30°
C.;
or(c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α
-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α
-olefin interpolymer is substantially free of a cross-linked phase;
Re>
1481−
1629(d);
or(d) has a molecular fraction which elutes between 40°
C. and 130°
C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α
-olefin interpolymer;
or(e) has a storage modulus at 25°
C., G′
(25°
C.), and a storage modulus at 100°
C., G′
(100°
C.), wherein the ratio of G′
(25°
C.) to G′
(100°
C.) is in the range of about 1;
1 to about 9;
1.
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Abstract
The present invention relates to film layers and compositions having improved hot tack properties. The compositions comprise at least one ethylene/α-olefin interpolymer, wherein the ethylene/α-olefin interpolymer may have, for example, a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:
Tm>−2002.9+4538.5(d)−2422.2(d)2.
120 Citations
15 Claims
-
1. A composition exhibiting high hot tack comprising at least one ethylene/α
- -olefin multi-block interpolymer, wherein the ethylene/α
-olefin interpolymer comprises at least 60 mole percent ethylene and;(a) has a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship;
Tm>
−
2002.9 +4538.5(d)−
2422.2(d)2;
or(b) has a Mw/Mn from about 1.7 to about 3.5, and is characterized by a heat of fusion, Δ
H in J/g, and a delta quantity, Δ
T, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of Δ
T and Δ
H have the following relationships;
Δ
T>
−
0.1299(Δ
H)+62.81 for Δ
H greater than zero and up to 130 J/g,
Δ
T≧
48°
C. for Δ
H greater than 130 J/g,wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30°
C.;
or(c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α
-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α
-olefin interpolymer is substantially free of a cross-linked phase;
Re>
1481−
1629(d);
or(d) has a molecular fraction which elutes between 40°
C. and 130°
C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α
-olefin interpolymer;
or(e) has a storage modulus at 25°
C., G′
(25°
C.), and a storage modulus at 100°
C., G′
(100°
C.), wherein the ratio of G′
(25°
C.) to G′
(100°
C.) is in the range of about 1;
1 to about 9;
1.
- -olefin multi-block interpolymer, wherein the ethylene/α
-
2. A heat-sealable film layer composition comprising at least one ethylene/α
- -olefin multi-block interpolymer, wherein the ethylene/α
-olefin interpolymer comprises at least 60 mole percent ethylene and;(a) has a Mw/Mn from about 1.7 to about 3.5, at least one melting point, Tm, in degrees Celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship;
Tm>
−
2002.9+4538.5(d)−
2422.2(d)2;
or(b) has a Mw/Mn from about 1.7 to about 3.5, and is characterized by a heat of fusion, Δ
H in J/g, and a delta quantity, Δ
T, in degrees Celsius defined as the temperature difference between the tallest DSC peak and the tallest CRYSTAF peak, wherein the numerical values of Δ
T and Δ
H have the following relationships;
Δ
T>
−
0.1299(Δ
H)+62.81 for Δ
H greater than zero and up to 130 J/g,
Δ
T≧
48°
C. for Δ
H greater than 130 J/g,wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has an identifiable CRYSTAF peak, then the CRYSTAF temperature is 30°
C;
or(c) is characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle measured with a compression-molded film of the ethylene/α
-olefin interpolymer, and has a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when ethylene/α
-olefin interpolymer is substantially free of a cross-linked phase;
Re>
1481−
1629(d);(d) has a molecular fraction which elutes between 40°
C. and 130°
C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α
-olefin interpolymer;
or(e) has a storage modulus at 25°
C., G′
(25°
C.), and a storage modulus at 100°
C., G′
(100°
C.), wherein the ratio of G′
(25°
C.) to G′
(100°
C.) is in the range of about 1;
1 to about 9;
1;wherein the ethylene/α
-olefin interpolymer has a density of from about 0.89 g/cc to about 0.94 g/cc.- View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- -olefin multi-block interpolymer, wherein the ethylene/α
Specification