Adhesives comprising amorphous propylene-ethylene copolymers
View Patent ↗Amorphous propylene-ethylene copolymers are described herein that can include high amounts of ethylene and exhibit desirable softening points and needle penetrations. The desirable combinations of softening points and needle penetrations in these propylene-ethylene copolymers allow them to have a broad operating window. Due their broad operating window, the propylene-ethylene copolymers can be utilized in a wide array of applications and products, including hot melt adhesives.
1. An adhesive comprising a propylene-ethylene copolymer, wherein said propylene-ethylene copolymer comprises at least 10 weight percent of ethylene and a softening point of at least 99° C.
2. The adhesive of claim 1 , wherein said propylene-ethylene copolymer comprises 12 to 40 weight percent of ethylene.
3. The adhesive of claim 1 , wherein said propylene-ethylene copolymer comprises a softening point in the range of 105 to 145° C.
4. The adhesive of claim 1 , wherein said propylene-ethylene copolymer comprises a needle penetration in the range of 8 to 75 dmm as measured according to ASTM D5.
5. The adhesive of claim 1 , wherein said propylene-ethylene copolymer comprises a crystallinity of less than 30 percent as measured using DSC according to ASTM E 794-85 and a number average molecular weight (Mn) of less than 25,000 as determined by gel permeation chromatography.
6. The adhesive of claim 1 , wherein said propylene-ethylene copolymer comprises a Brookfield viscosity at 190° C. of less than 30,000 cps as measured according to ASTM D3236.
7. The adhesive of claim 1 , wherein said propylene-ethylene copolymer exhibits a glass transition temperature (Tg) in the range of −60 to 20° C.
8. The adhesive of claim 1 , wherein said adhesive comprises:
(a) 5 to 95 weight percent of said propylene-ethylene copolymer;
(b) not more than 55 weight percent of a propylene polymer or a metallocene-catalyzed polyolefin;
(c) not more than 55 weight percent of at least one tackifier;
(d) not more than 20 weight percent of a processing oil; and
(e) not more than 20 weight percent of a wax.
9. An adhesive comprising:
(i) a first propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer comprises a polydispersity of at least 3, at least 10 weight percent of ethylene, and a softening point of at least 99° C.;
(ii) a second propylene-ethylene copolymer or a metallocene-catalyzed polyolefin; and
(iii) optionally, at least one polyolefin selected from the group consisting of amorphous polyolefins, semi-crystalline polyolefins, alpha-polyolefins, reactor-ready polyolefins, metallocene-catalyzed polyolefin polymers and elastomers, reactor-made thermoplastic polyolefin elastomers, olefin block copolymers, thermoplastic polyolefins, atactic polypropylene, polyethylenes, ethylene-propylene polymers, propylene-hexene polymers, ethylene-butene polymers, ethylene-octene polymers, propylene-butene polymers, propylene-octene polymers, metallocene-catalyzed polypropylene polymers, metallocene-catalyzed polyethylene polymers, propylene-based terpolymers including ethylene-propylene-butylene terpolymers, copolymers produced from propylene and linear or branched C 4 -C 10 alpha-olefin monomers, copolymers produced from ethylene and linear or branched C 4 -C 10 alpha-olefin monomers, and functionalized polyolefins.
10. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise 10 to 40 weight percent of ethylene and a softening point in the range of 99 to 145° C.
11. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise 15 to 35 weight percent of ethylene.
12. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise a Brookfield viscosity at 190° C. of less than 30,000 cps as measured according to ASTM D3236.
13. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise a polydispersity in the range of 3 to 25.
14. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise a needle penetration in the range of 8 to 75 dmm as measured according to ASTM D5.
15. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer comprise a crystallinity of less than 30 percent as measured using DSC according to ASTM E 794-85 and a number average molecular weight (Mn) of less than 20,000 as determined by gel permeation chromatography.
16. The adhesive of claim 9 , wherein said adhesive comprises said second propylene-ethylene copolymer, wherein said first propylene-ethylene copolymer and/or said second propylene-ethylene copolymer exhibit a melt temperature in the range of 90° C. to 135° C.
17. The adhesive of claim 9 , wherein said adhesive comprises:
(a) 20 to 75 weight percent of said first propylene-ethylene copolymer;
(b) 1 to 30 weight percent of said second propylene-ethylene copolymer;
(c) not more than 55 weight percent of at least one tackifier;
(d) not more than 20 weight percent of a processing oil; and
(e) not more than 20 weight percent of a wax.
18. The adhesive of claim 9 , wherein said adhesive comprises:
(a) 20 to 75 weight percent of said first propylene-ethylene copolymer;
(b) 1 to 50 weight percent of said metallocene-catalyzed polyolefin;
(c) not more than 55 weight percent of at least one tackifier;
(d) not more than 20 weight percent of a processing oil; and
(e) not more than 20 weight percent of a wax.
19. An article comprising the adhesive of claim 1 wherein said article is selected from the group consisting of adhesives, sealants, caulks, roofing membranes, waterproof membranes and underlayments, carpet, laminates, laminated articles, tapes, mastics, polymer blends, wire coatings, molded articles, heat seal coatings, disposable hygiene articles, insulating glass (IG) units, bridge decking, water proofing membranes, waterproofing compounds, underlayments, cable flooding/filling compounds, sheet molded compounds, dough molded compounds, overmolded compounds, rubber compounds, polyester composites, glass composites, fiberglass reinforced plastics, wood-plastic composites, polyacrylic blended compounds, lost-wax precision castings, investment casting wax compositions, candles, windows, films, gaskets, seals, o-rings, motor vehicle molded parts, motor vehicle extruded parts, clothing articles, rubber additive/processing aids, and fibers.
20. An article comprising the adhesive of claim 9 wherein said article is selected from the group consisting of adhesives, sealants, caulks, roofing membranes, waterproof membranes and underlayments, carpet, laminates, laminated articles, tapes, mastics, polymer blends, wire coatings, molded articles, heat seal coatings, disposable hygiene articles, insulating glass (IG) units, bridge decking, water proofing membranes, waterproofing compounds, underlayments, cable flooding/filling compounds, sheet molded compounds, dough molded compounds, overmolded compounds, rubber compounds, polyester composites, glass composites, fiberglass reinforced plastics, wood-plastic composites, polyacrylic blended compounds, lost-wax precision castings, investment casting wax compositions, candles, windows, films, gaskets, seals, o-rings, motor vehicle molded parts, motor vehicle extruded parts, clothing articles, rubber additive/processing aids, and fibers.