Sprayable hot melt adhesives

• US 6,582,762 B2
• Filed: 04/20/2001
• Issued: 06/24/2003
• Est. Priority Date: 12/22/1999
• Status: Expired due to Term

• Current Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Chemical Patents Inc. (Exxon Mobil Corporation)
• Inventors: Sims, Charles L., Karandinos, Anthony G., Georjon, Olivier J., Faissat, Michel L.
• Primary Examiner(s): PIANALTO, BERNARD D
• Application Number:
  US09/839,316
• Publication Number:
  US 20020039623A1
• Time in Patent Office: 795 Days
• Field of Search: 427/422, 427/208.2, 427/265, 427/407.1, 427/421
• US Class Current: 427/208.2
• CPC Class Codes: C08F 210/06 Propene
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/03 Narrow molecular weight distribution, i.e. Mw/Mn < 3
• CPC Class Codes: C08F 2500/12 Melt flow index or melt flow ratio
• CPC Class Codes: C08F 2500/17 Viscosity
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 23/10 Homopolymers or copolymers of propene
• CPC Class Codes: C08L 2314/06 Metallocene or single site catalysts
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C09J 123/10 Homopolymers or copolymers of propene
• CPC Class Codes: C09J 123/14 Copolymers of propene C09J123/16 takes precedence

Abstract

This invention relates to a process for atomizing, spiral spraying, oscillation spraying or melt blowing propylene copolymers onto a substrate comprising selecting a poly-alpha olefin inter-polymer comprising:

A) from 60 to 94% of units derived from an alpha mono-olefin having from 3 to 6 carbon atoms and

B) from 6 to 40 mol % of units derived from ethylene or one or more other mono-olefins having from 4 to 10 carbon atoms and at least one carbon atom more than A); and

C) optionally from 0 to 10 mol % of units derived from another copolymerizable unsaturated hydrocarbon, different from A) and B);

wherein the inter-polymer has:

i) an Mw/Mn of 6 or less;

ii) a storage modulus G′, determined upon cooling, intersecting a value of 0.3 M Pa at a temperature of less than 85° C.;

iii) a G″/G′ ratio of 18 or more when G′ is 10 Pa when measured at a frequency of 1 hz; and

iv) a viscosity of 5000 mPa·sec or less at 190° C., and

atomizing, spiral spraying, oscillation spraying or melt blowing the inter-polymer into a substrate.

Blends of the above copolymers can also be used herein.

Claims

1. A process for atomizing, spiral spraying, oscillation spraying or melt blowing copolymers onto a substrate comprising selecting a poly-alpha olefin inter-polymer comprising:

A) from 60 to 94 mol % of units derived from an alpha mono-olefin having from 3 to 6 carbon atoms and

B) from 6 to 40 mol % of units derived from ethylene or one or more other mono-olefins having from 4 to 10 carbon atoms and at least one carbon atom more than A); and

C) optionally from 0 to 10 mol % of units derived from another copolymerizable unsaturated hydrocarbon, different from A) and B);

wherein the inter-polymer has;

i) an Mw/Mn of 6 or less;

ii) a storage modulus G′

, determined upon cooling, intersecting a value of 0.3 M Pa at a temperature of less than 85°

C. measured at a frequency of 1 Hz;

iii) a G″

/G′

ratio of 18 or more when G′

is 10 Pa; and

iv) a viscosity of 5000 mPa·

sec or less at 190°

C., and

atomizing, spiral spraying, oscillation spraying or melt blowing the inter-polymer onto a substrate.

2. The process of claim 1 in which the content of B) combined with C) is at least 8 mol % and is less than 40 mol % and the storage modulus G′

of said inter-polymer intersects a value of G′

of 0.3 MPa at a temperature of less than 70°

C., when measured at 1 Hz.

3. The process of claim 1 wherein the reactivity ratio of component A) to component B) has a value of R_A×

R_B of less than 1.4, where R_A is the reactivity ratio of component A) over component B) and R_B is the ratio of component B) over component A).

4. The process of claim 1 wherein the inter-polymer has a weight average molecular weight of 20,000 to 120,000 and the storage modulus G′

of the inter-polymer intersects a value of 0.3 MPa at a temperature of less than 70°

C. when measured at 1 Hz.

5. The process of claim 1 wherein A) is derived from propylene.

6. The process of claim 1 wherein B) is derived from units having from 4 to 8 carbon atoms.

7. The process of claim 5 wherein B) is derived from butene-1, hexene-1 and or octene-1.

8. The process of claim 1 wherein C) is derived from ethylene.

9. The process of claim 7 wherein C) is derived from ethylene.

10. The process of claim 1 wherein the inter-polymer has a melting behavior wherein the major peak melting point varies with content of component B) plus C) so that T_m (interpolymer) is less than 153−

2.78×

[C_B+C] for any given concentration of B) and/or C) components. Where Tm is the major melting peak of the interpolymer at a given content of components B) and C) in mol %;

[C_B+C] is the mol % of component B) plus C).

11. The process of claim 1 wherein

units derived from A) are present at 65 to 94 mole %,

units derived from B) are present at 6 to 35 mole %, and

units derived from C) are present at 0 to 10 mole %.

12. The process of claim 1 wherein

units derived from A) are present at 75 to 90 mole %,

units derived from B) are present at 10 to 30 mole %, and

units derived from C) are present at 0.5 to 5 mole %.

13. The process of claim 1 wherein

units derived from A) are present at 87 to 73 mole %,

units derived from B) are present at 12 to 25 mole %, and

units derived from C) are present at 1 to 2 mole %.

14. The process of claim 1 wherein the inter-polymer has a heat of fusion of at least 5 J/g and no more than 40 J/g.

15. The process of claim 1 wherein the inter-polymer has a heat of fusion of at least 10 J/g and no more than 30 J/g.

16. The process of claim 1 wherein the inter-polymer has a major melting peak of at least 40°

C. and no more than 130°

C.

17. The process of claim 1 wherein the inter-polymer has a major melting peak of at least 40°

C. and no more than 90°

C.

18. The process of claim 1 wherein the inter-polymer has a Tg of −

5°

C. or less.

19. The process of claim 1 wherein the inter-polymer has a Tg between −

5°

C. and −

40°

C.

20. The process of claim 1 wherein the G″

/G′

ratio of is 20 or more when G′

is 10 Pa.

21. The process of claim 1 wherein the G″

/G′

ratio is 22 or more when G′

is 10 Pa.

22. The process of claim 1 wherein the inter-polymer has an Mw/Mn of 3 or less.

23. The process of claim 1 wherein the inter-polymer has an Mw/Mn between 2.5 and 1.6.

24. The process of claim 1 wherein the inter-polymer is sprayed at a machine speed of no less than 50 m/min.

25. The process of claim 24 wherein the inter-polymer being sprayed has a filament diameter of at least 0.2 mm and no more than 1.0 mm.

26. The process of claim 25 wherein the inter-polymer being sprayed has a spiral diameter of at least 8 mm and no more than 30 mm.

27. The process of claim 1 wherein the inter-polymer is sprayed at a machine speed of no less than 400 m/min.

28. The process of claim 27 wherein the inter-polymer being sprayed has a spiral diameter of at least 5 mm and no more than 40 mm.

29. The process of claim 27 wherein the inter-polymer being sprayed has a filament diameter of at least 0.3 mm and no more than 0.6 mm.

30. The process of claim 29 wherein the inter-polymer being sprayed has a spiral diameter of at least 10 mm and no more than 20 mm.

31. The process of claim 1 wherein the sprayed interpolymer has an adhesion to nonwoven coverstock or polyethylene film at about 20°

C. of at least 5 g/spiral.

32. The process of claim 1 wherein the sprayed interpolymer has an adhesion to nonwoven coverstock or polyethylene film at about 20°

C. of at least 10 g/spiral.

33. The process of claim 1 wherein the sprayed interpolymer has an adhesion to nonwoven coverstock or polyethylene film at about 20°

C. of at least 35 g/spiral.

34. The process of claim 1 wherein the inter-polymer is produced from polymerization of the monomers (−

A), B) and C)−

) using a metallocene in combination with a co-catalyst.

35. The process of claim 1 wherein the comonomer comprises ethylene and or a C₄ to C₄₀ linear, cyclic or branched alpha-olefin.

36. The process of claim 1 wherein the comonomer comprises one or more of ethylene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, 3,5,5-trimethyl hexene-1, 3-methylpentene-1, 4-methylpentene-1.

37. The process of claim 1 wherein the G″

/G′

ratio is 50 or more when G′

is 10 Pa.

38. The process of claim 1 wherein the G″

/G′

ratio is 40 or more when G′

is 10 Pa.

39. The process of claim 1 wherein the G″

/G′

ratio is 30 or more when G′

is 10 Pa.

40. A process for spraying blends of propylene copolymers comprising selecting two or more different copolymers independently comprising propylene and up to 50 mole % comonomer, each copolymer independently having:

an Mw of between 20,000 to 100,000;

an Mw/Mn of 4 or less;

,

a G″

/G′

of 18 or more, when G′

is 10 Pa;

a Tg of about −

5°

C. or less;

a Tm of about 90°

C. or less;

an amorphous content of at least 50%,

a crystallinity of less than 15%,

a heat of fusion of at least 5 J/g

a viscosity of 5000 mPa·

sec or less at 190°

C.; and

a melting range of less than 75°

C.,

combining the two or more copolymers, and optionally oil, into a blend; and

atomizing, spiral spraying, oscillation spraying or melt blowing the blend onto a substrate.

41. A process for atomizing, spiral spraying, oscillation spraying or melt blowing a blend of propylene copolymers onto a substrate comprising selecting two or more different poly-alpha olefin inter-polymers wherein each polymer independently comprises:

A) from 60 to 94% of units derived propylene and

B) from 6 to 40 mol % of units derived from one or more of butene, hexene and octene; and

C) optionally from 0 to 10 mol % of units derived from ethylene;

wherein each inter-polymer independently has;

i) a diad distribution of propylene in the inter-polymer showing a ratio of experimentally determined diad distribution over the calculated Bemoullian diad distribution of less than 1.07;

ii) a storage modulus G′

, determined upon cooling, intersecting a value of 0.3 M Pa at a temperature of less than 85°

C. measured at a frequency of 1 Hz;

iii) a G″

/G′

ratio of 18 or more when G′

is 10 Pa; and

iv) a viscosity of 5000 mPa·

sec or less at 190°

C., and

combining the inter-polymers into a blend and

atomizing, spiral spraying, oscillation spraying or melt blowing the blend onto a substrate.

42. A process for atomizing, spiral spraying, oscillation spraying or melt blowing propylene copolymers onto a substrate comprising selecting a poly-alpha olefin inter-polymer comprising:

A) from 60 to 94% of units derived propylene and

B) from 6 to 40 mol % of units derived from one or more of butene, hexene and octene;

wherein the inter-polymer has;

i) a diad distribution of propylene in the inter-polymer showing a ratio of experimentally determined diad distribution over the calculated Bernoullian diad distribution of less than 1.07;

ii) a storage modulus G′

, determined upon cooling, intersecting a value of 0.3 M Pa at a temperature of less than 85°

C. measured at a frequency of 1 Hz;

iii) a G″

/G′

ratio of 18 or more when G′

is 10 Pa; and

iv) a viscosity of 5000 mPa·

sec or less at 190°

C., and

atomizing, spiral spraying, oscillation spraying or melt blowing the inter-polymer onto a substrate.

43. A process for atomizing, spiral spraying, oscillation spraying or melt blowing a blend of copolymers onto a substrate comprising selecting two or more different poly-alpha olefin inter-polymers wherein each inter-polymer independently comprises:

A) from 60 to 94 mol % of units derived from an alpha mono-olefin having from 3 to 6 carbon atoms and

B) from 6 to 40 mol % of units derived from ethylene or one or more other mono-olefins having from 4 to 10 carbon atoms and at least one carbon atom more than A); and

C) optionally from 0 to 10 mol % of units derived from another copolymerizable unsaturated hydrocarbon, different from A) and B);

wherein each inter-polymer has;

i) an Mw/Mn of 6 or less;

ii) a storage modulus G′

, determined upon cooling, intersecting a value of 0.3 M Pa at a temperature of less than 85°

C. measured at a frequency of 1 Hz;

iii) a G″

/G′

ratio of 18 or more when G′

is 10 Pa; and

iv) a viscosity of 5000 mPa·

sec or less at 190°

C., and

combining the inter-polymers into a blend, and

atomizing, spiral spraying, oscillation spraying or melt blowing the blend onto a substrate.

44. A process for spraying propylene copolymers comprising selecting a hot melt adhesive composition comprising a copolymer comprising propylene and up to 50 mole % comonomer, said copolymer having

an Mw of between 20,000 to 100,000;

an Mw/Mn of 4 or less;

,

a G″

/G′

of 18 or more, when G′

is 10 Pa;

a Tg of about −

5°

C. or less;

a Tm of about 90°

C. or less;

an amorphous content of at least 50%,

a crystallinity of less than 15%,

a heat of fusion of at least 5 J/g

a viscosity of 5000 mPa·

sec or less at 190°

C.; and

a melting range of less than 75°

C., and

atomizing, spiral spraying, oscillation spraying or melt blowing the hot melt adhesive selected onto a substrate.

45. The process of claim 44 wherein the copolymer has a melting range of 50°

C. or less.

46. The process of claim 44 wherein the G″

/G′

ratio is 20 or more when G′

is 10 Pa.