Adhesive compositions of ethylene-based and propylene-based polymers

Patent metadata

Field	Value
Publication number	US-9605186-B2
Application number	US-201314428137-A
Country	US
Kind code	B2
Filing date	Oct 2, 2013
Priority date	Sep 19, 2012
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

The present invention is related to adhesive compositions and their applications. In particular, the adhesive compositions described herein comprise an ethylene-based polymer and a propylene-based polymer with varying comonomer content.

First claim

What is claimed is:

1. An adhesive composition comprising:
(a) an ethylene-based polymer comprising more than 50 wt. % of ethylene-derived units and in the range of 1 wt. % to 49 wt. % of units derived from a first comonomer, 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 of less than about 250 J/g measured by ASTM D-3418-03, wherein the weight percent measurements are based on the weight of the ethylene-based polymer;
(b) a propylene-based polymer comprising more than 50 wt. % propylene-derived units and in the range of 1 wt. % to 49 wt. % of units derived from a second comonomer, said propylene-based polymer having a Brookfield viscosity in the range from 100 mPa·sec to 1500 mPa·sec measured by ASTM D-3236 at 190° C., a heat of fusion of at least 45 J/g measured by ASTM D-3418-03, wherein the weight percent measurements are based on the weight of the propylene-based polymer;

wherein said ethylene-based polymer and said propylene-based polymer each have a characteristic time (t c ) of at least 0.1 nanoseconds, 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 ethylene-based polymer or said propylene-based polymer measured by ASTM D-3236 at 190° C. in units of mPa·sec, said Density is the density of said ethylene-based polymer or said propylene-based polymer measured by ASTM D-1505-10 at 23° C. in units of g/cm 3 , and said Heat of Fusion is the heat of fusion of said ethylene-based polymer or said propylene-based polymer measured by ASTM D-3418-03 in units of J/g.

2. The adhesive composition of claim 1 , wherein said first comonomer is selected from the group consisting of propylene, a C 4 to C 20 alpha-olefin, and combinations thereof.

3. The adhesive composition of claim 2 , wherein said first comonomer comprises propylene, butene or octene.

4. 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.

5. The adhesive composition of claim 1 , wherein said heat of fusion measured by ASTM D-3418-03 of said ethylene-based polymer is from 20 to 250 J/g.

6. The adhesive composition of claim 1 , wherein said characteristic time (t c ) of said ethylene-based polymer is from 1 to 1000 nanoseconds.

7. 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.

8. The adhesive composition of claim 1 , wherein said second comonomer is selected from the group consisting of ethylene, a C 4 to C 20 alpha-olefin, and combinations thereof.

9. The adhesive composition of claim 8 , wherein said second comonomer comprises ethylene.

10. The adhesive composition of claim 1 , wherein said heat of fusion measured by differential scanning calorimetry of said propylene-based polymer is from 45 to 75 J/g.

11. The adhesive composition of claim 1 , wherein said characteristic time (t c ) of said propylene-based polymer is from 1 to 100 nanoseconds.

12. The adhesive composition of claim 1 , wherein said first comonomer and said second comonomer are the same or different.

13. 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.

14. The adhesive composition of claim 13 , wherein said adhesive composition has one or more of the following properties:
(i) a Brookfield viscosity of 250 to 10,000 mPa·sec measured by ASTM D-3236 at 177° C.;
(ii) an Average percent Fiber Tear greater than 99%, wherein Average percent Fiber Tear is defined by: Average percent Fiber Tear=(percent Fiber Tear at 25° C.+percent Fiber Tear at 2° C.+percent Fiber Tear at −18° C.)/3;
(iii) an adhesion set time of less than 5 seconds;
(iv) 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;
(v) a calculated density of said adhesive composition at 23° C. lower than about 0.9100 g/cm 3 , wherein said calculated density is determined from the weight percent and the density of each component is said adhesive composition;
(vi) a heat of fusion (H f ) of said adhesive composition of about 19 J/g to about 45 J/g; and/or
(vii) a hot melt adhesive characteristic time (HMA t c ) from about 15 nanoseconds to about 100 nanoseconds, said HMA characteristic time (HMA t c ) defined by:

HMA
⁢

⁢

t
c

=

BV
⁢

⁢
at
⁢

⁢
177
⁢
°
⁢

⁢

C
.

Density
×
Heat
⁢

⁢
of
⁢

⁢
Fusion

wherein said BV is the Brookfield viscosity of said adhesive composition measured by ASTM D-3236 at 177° C. in units of mPa·sec, said Density is the calculated density of said adhesive composition at 23° C. in units of g/cm 3 , and said Heat of Fusion is the heat of fusion of said adhesive composition measured by ASTM D-3418-03 in units of J/g.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Tse Mun Fu

Classifications

• C09J123/142 Primary

  at least partially crystalline copolymers of propene with other olefins · CPC title

• C09J123/0815

  Copolymers of ethene with aliphatic 1-olefins · CPC title

• C08K5/13

  Phenols; Phenolates · CPC title

• C09J123/14

  Copolymers of propene (C09J123/16 takes precedence) · CPC title

• C08L23/08

  Copolymers of ethene (C08L23/16 takes precedence) · CPC title