Adhesive compositions of propylene-based and ethylene-based polymers
The present invention is related to adhesive compositions and their applications. In particular, the adhesive compositions described herein comprise a propylene-based polymer and an ethylene-based polymer with varying comonomer content.
1. An adhesive composition comprising:
(a) at least one propylene-based polymer comprising more than 50 wt % of propylene-derived units and at least one first comonomer-derived units, said propylene-based polymer having a Brookfield viscosity of at least 250 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion of at least 60 J/g measured by differential scanning calorimetry and a characteristic time (t c ) in the range from 1 to 1000 nanoseconds;
(b) an ethylene-based polymer comprising more than 50 wt % ethylene-derived units and at least one second comonomer-derived units, said ethylene-based polymer having a Brookfield viscosity of at least 250 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion in the range from 1 to 100 J/g measured by differential scanning calorimetry and a characteristic time (t c ) in the range from 1 to 1500 nanoseconds;
wherein said at least one first comonomer and said at least one second comonomer are the same or different;
wherein said characteristic time (t c ) in units of nanoseconds is defined by Equation 1:
t
c
=
BV
Density
×
Heat
of
Fusion
(
Equation
1
)
wherein said BV is the Brookfield viscosity of said propylene-based polymer or said ethylene-based polymer measured by ASTM D-3236 at 190° C. in units of mPa·sec, said Density is the density of said propylene-based polymer or said ethylene-based polymer in units of g/cm 3 at 23° C., and said Heat of Fusion is the heat of fusion of said propylene-based polymer or said ethylene-based polymer in units of J/g.
2. The adhesive composition of claim 1 , wherein said at least one first comonomer is selected from the group consisting of ethylene and a C 4 to C 20 alpha-olefin.
3. The adhesive composition of claim 1 , wherein said at least one first comonomer comprises ethylene.
4. The adhesive composition of claim 1 , wherein said propylene-based polymer comprises 90 wt % to 99 wt % of propylene-derived units and 10 wt % to 1 wt % of ethylene-derived units, based on the weight of said propylene-based polymer.
5. The adhesive composition of claim 1 , wherein said Brookfield viscosity measured by ASTM D-3236 at 190° C. of said propylene-based polymer is from 250 to 25,000 mPa·sec.
6. The adhesive composition of claim 1 , wherein said heat of fusion measured by differential scanning calorimetry of said propylene-based polymer is from 60 to 150 J/g.
7. The adhesive composition of claim 1 , wherein said characteristic time (t c ) of said propylene-based polymer is from 1 to 800 nanoseconds.
8. The adhesive composition of claim 1 , wherein said propylene-based polymer has a ratio of a weight-average molecular weight (M w ) to a number-average molecular weight (M n ) in the range from 2 to 10.
9. The adhesive composition of claim 1 , wherein said at least one second comonomer is a C 3 to C 20 alpha-olefin.
10. The adhesive composition of claim 1 , wherein said at least one second comonomer comprises octene.
11. The adhesive composition of claim 1 , wherein said ethylene-based polymer comprises 51 wt % to 99 wt % of ethylene-derived units and 49 wt % to 1 wt % of octene-derived units, based on the weight of the said ethylene-based polymer.
12. The adhesive composition of claim 1 , wherein said Brookfield viscosity measured by ASTM D-3236 at 190° C. of said ethylene-based polymer is from 250 to 50,000 mPa·sec.
13. The adhesive composition of claim 1 , wherein said heat of fusion measured by differential scanning calorimetry of said ethylene-based polymer is from 1 to 60 J/g.
14. The adhesive composition of claim 1 , wherein said characteristic time (t c ) of said ethylene-based polymer is from 1 to 1200 nanoseconds.
15. The adhesive composition of claim 1 , wherein said ethylene-based polymer has a ratio of a weight-average molecular weight (M w ) to a number-average molecular weight (M n ) in the range from 1 to 10.
16. The adhesive composition of claim 1 , wherein said first comonomer and said second comonomer are different, said first comonomer is ethylene, and said second comonomer is octene.
17. The adhesive composition of claim 1 , further comprising one or more additives, said additives selected from the group consisting of a functionalized component, a tackifier component, a process oil component, a wax component, an antioxidant component, or a mixture thereof.
18. The adhesive composition of claim 1 , wherein said adhesive composition comprises 99 wt % to 1 wt % of said propylene-based polymer and 1 wt % to 99 wt % of said ethylene-based polymer, based on the weight of said adhesive composition.
19. The adhesive composition of claim 1 , wherein said adhesive composition has a Brookfield viscosity measured by ASTM D-3236 at 177° C. is from 250 to 30,000 mPa·sec.
20. The adhesive composition of claim 1 , wherein said adhesive composition has a melting temperature measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min is no more than 130° C.
21. The adhesive composition of claim 1 , wherein said adhesive composition has one or more of the following properties:
(i) a Brookfield viscosity of 250 to 5000 mPa·sec measured by ASTM D-3236 at 177° C.;
(ii) a percent fiber tear at 25° C. greater than or equal to 85%;
(iii) a percent fiber tear at 2° C. greater than or equal to 80%;
(iv) a percent fiber tear at −18° C. greater than or equal to 75%;
(v) an adhesion set time of 6 seconds or less; and
(vi) a melting temperature (T m ) of 130° C. or less measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min.
22. An adhesive composition comprising:
(a) a propylene-based polymer comprising from 50 wt % to 100 wt % propylene-derived units and from 0 wt % to 50 wt % ethylene-derived units, said propylene-based polymer having a Brookfield viscosity in the range of 250 to 25,000 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion in the range of 60 to 150 J/g measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min and a characteristic time (t c ) in the range from 1 to 1000 nanoseconds;
(b) an ethylene-based polymer comprising from 50 wt % to 100 wt % ethylene-derived units and from 0 wt % to 50 wt % octene-derived units, said ethylene-based polymer having a Brookfield viscosity in the range of 250 to 50,000 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion in the range of 1 to 100 J/g measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min and a characteristic time (t c ) in the range from 1 to 1500 nanoseconds;
wherein said characteristic time (t c ) is defined by Equation 1:
t
c
=
BV
Density
×
Heat
of
Fusion
(
Equation
1
)
wherein said BV is the Brookfield viscosity of said propylene-based or said ethylene-based polymer measured by ASTM D-3236 at 190° C. in units of mPa·sec, said Density is the density of said propylene-based or said ethylene-based polymer in units of g/cm 3 at 23° C., and said Heat of Fusion is the heat of fusion of said propylene-based or said ethylene-based polymer in units of J/g.
23. The adhesive composition of claim 1 , wherein the ratio of said characteristic time (t c ) of said propylene-based polymer to said characteristic time (t c ) of said ethylene-based polymer is from 1 to 1000.
24. A hot melt adhesive composition comprising:
(a) 40 wt % to 60 wt % of a propylene-based polymer based on the weight of said hot melt adhesive, said propylene-based polymer comprising from 50 wt % to 100 wt % propylene- derived units, and 0 wt % to 50 wt % ethylene-derived units, said propylene-based polymer having a Brookfield viscosity in the range of 250 to 25,000 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion in the range of 60 to 150 J/g measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min and a characteristic time (t c ) in the range from 1 to 1000 nanoseconds;
(b) 40 wt % to 60 wt % of an ethylene-based polymer based on the weight of said hot melt adhesive, said ethylene-based polymer comprising from 50 wt % to 100 wt % ethylene- derived units and from 0 wt % to 50 wt % octene-derived units, said ethylene-based polymer having a Brookfield viscosity in the range of 250 to 50,000 mPa·sec measured by ASTM D-3236 at 190° C., and a heat of fusion in the range of 1 to 100 J/g measured by differential scanning calorimetry at second melt with a heating rate of 10° C./min and a characteristic time (t c ) in the range from 1 to 1500 nanoseconds;
wherein said characteristic time (t c ) is defined by Equation 1:
t
c
=
BV
Density
×
Heat
of
Fusion
(
Equation
1
)
wherein said BV is the Brookfield viscosity of said propylene-based or said ethylene-based polymer measured by ASTM D-3236 at 190° C. in units of mPa·sec, said Density is the density of said propylene-based or said ethylene-based polymer in units of g/cm 3 at 23° C., and said Heat of Fusion is the heat of fusion of said propylene-based or said ethylene-based polymer in units of J/g; and
(c) at least one of a functionalized component, a tackier component, a process oil component, a wax component, an antioxidant component, or a mixture thereof.