Acrylate copolymeric fibers

• US 6,083,856 A
• Filed: 12/01/1997
• Issued: 07/04/2000
• Est. Priority Date: 12/01/1997
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Joseph, Eugene G., Williams, Kenneth C., Hoff, Randy A., Khandpur, Ashish, Stickels, Steven C., Clanton, Anthony R.
• Primary Examiner(s): DAVIS, JENNA L
• Application Number:
  US08/982,238
• Time in Patent Office: 946 Days
• Field of Search: 428/343, 428/355 AC, 442/361, 442/400, 442/401
• US Class Current: 442/361
• CPC Class Codes: D01F 6/36 comprising unsaturated carboxylic acids or unsaturated organic esters as the major constituent
• CPC Class Codes: D01F 8/10 with at least one other macromolecular compound obtained by reactions only involving carbon-to-carbon unsaturated bonds as constituent
• CPC Class Codes: D04H 1/4291 Olefin series
• CPC Class Codes: D04H 1/4334 Polyamides
• CPC Class Codes: D04H 1/435 Polyesters
• CPC Class Codes: D04H 1/4358 Polyurethanes
• CPC Class Codes: D04H 1/43828 sheath-core
• CPC Class Codes: D04H 1/4383 sea-island
• CPC Class Codes: D04H 1/43835 Mixed fibres, e.g. at least two chemically different fibres or fibre blends
• CPC Class Codes: D04H 1/43838 Ultrafine fibres, e.g. microfibres
• CPC Class Codes: D04H 1/56 in association with fibre formation, e.g. immediately following extrusion of staple fibres
• CPC Class Codes: Y10T 428/28 Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2891 including addition polymer from alpha-beta unsaturated carboxylic acid [e.g., acrylic acid, methacrylic acid, etc.] Or derivative thereof
• CPC Class Codes: Y10T 442/637 Including strand or fiber material which is a monofilament composed of two or more polymeric materials in physically distinct relationship [e.g., sheath-core, side-by-side, islands-in-sea, fibrils-in-matrix, etc.] or composed of physical blend of chemically different polymeric materials or a physical blend of a polymeric material and a filler material
• CPC Class Codes: Y10T 442/68 Melt-blown nonwoven fabric
• CPC Class Codes: Y10T 442/681 Spun-bonded nonwoven fabric

Abstract

The present invention provides fibers and products produced therefrom, including nonwoven webs and adhesive articles. The fibers, which can be multilayer fibers, include a pressure-sensitive adhesive composition comprising an acrylate copolymer comprising copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer and at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer.

Claims

1. A pressure-sensitive adhesive fiber comprising a pressure-sensitive adhesive composition comprising a crosslinked melt-processable acrylate copolymer as a structural component of the fiber, wherein the crosslinked melt-processable acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer, at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer, and a crosslinking agent;

wherein the crosslinking agent crosslinks subsequent to fiber formation.

2. The fiber of claim 1 wherein the alkyl (meth)acrylate monomer when homopolymerized has a glass transition temperature of no greater than about 0°

C., and wherein the free-radically copolymerizable reinforcing monomer when homopolymerized has a glass transition temperature of at least about 10°

C.

3. The fiber of claim 1 further comprising at least one secondary melt processable polymer or copolymer mixed with the acrylate copolymer.

4. The fiber of claim 3 wherein the secondary melt processable polymer or copolymer is selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

5. The fiber of claim 4 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.

6. The fiber of claim 1 wherein the pressure-sensitive adhesive composition further comprises a tackifier mixed with the acrylate copolymer.

7. The fiber of claim 1 wherein the acrylate copolymer has an apparent viscosity in the melt in a range of about 150 poise to about 800 poise.

8. The fiber of claim 1 wherein the monofunctional alkyl (meth)acrylate monomer is selected from the group of 2-methylbutyl acrylate, isooctyl acrylate, lauryl acrylate, poly(ethoxylated) methoxy acrylate, and mixtures thereof.

9. The fiber of claim 1 wherein the free-radically copolymerizable reinforcing monomer is a monofunctional (meth)acrylic monomer.

10. The fiber of claim 9 wherein the monofunctional (meth)acrylic reinforcing monomer is selected from the group of an acrylic acid, a methacrylic acid, an acrylate, an acrylamide, and mixtures thereof.

11. The fiber of claim 10 wherein the monofunctional (meth)acrylic reinforcing monomer is selected from the group of acrylic acid, N,N-dimethyl acrylamide, 1,1,3,3-tetramethylbutyl acrylamide, 2-hydroxypropyl acrylate, 2-(phenoxy)ethyl acrylate, and mixtures thereof.

12. The fiber of claim 1 wherein the crosslinking agent is copolymerized with the monofunctional alkyl (meth)acrylate monomer and the reinforcing monomers.

13. The fiber of claim 12 wherein the crosslinking agent is selected from the group of an acrylic crosslinking monomer, a polymeric crosslinking material having a copolymerizable vinyl group, and mixtures thereof.

14. The fiber of claim 13 wherein the polymeric material having a copolymerizable vinyl group is selected from the group of a (meth)acrylate-terminated polystyrene macromer and a (meth)acrylate-terminated polymethyl methacrylate macromer.

15. The fiber of claim 1 wherein the crosslinking agent forms chemical crosslinks.

16. The fiber of claim 1 wherein the crosslinking agent forms physical crosslinks.

17. A pressure-sensitive adhesive fiber which is in the form of a multilayer fiber comprising at least a first layer comprising a pressure-sensitive adhesive composition comprising an acrylate copolymer as a structural component of the fiber, wherein the acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer and at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer.

18. The fiber of claim 17 further comprising at least a second layer comprising a different acrylate copolymer.

19. The fiber of claim 17 further comprising at least a second layer comprising a secondary melt processable polymer or copolymer.

20. The fiber of claim 19 wherein the secondary melt processable polymer or copolymer is selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

21. The fiber of claim 20 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.

22. The fiber of claim 19 wherein the secondary melt processable polymer or copolymer is mixed with a tackifier.

23. A nonwoven web comprising pressure-sensitive adhesive fibers;

wherein the fibers comprise a pressure-sensitive adhesive composition comprising a crosslinked melt-processable acrylate copolymer as a structural component of the fibers;

wherein the crosslinked melt-processable acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer, at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer, and a crosslinking agent;

wherein the crosslinking agent crosslinks subsequent to fiber formation.

24. The nonwoven web of claim 23 wherein the alkyl (meth)acrylate monomer when homopolymerized has a glass transition temperature of no greater than about 0°

C., and wherein the free-radically copolymerizable reinforcing monomer when homopolymerized has a glass transition temperature of at least about 10°

C.

25. The nonwoven web of claim 23 wherein the fibers further comprise at least one secondary melt processable polymer or copolymer mixed with the acrylate copolymer.

26. The nonwoven web of claim 25 wherein the secondary melt processable polymer or copolymer is selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

27. The nonwoven web of claim 26 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.

28. The nonwoven web of claim 23 wherein the pressure-sensitive adhesive composition of the fibers further comprises a tackifier mixed with the acrylate copolymer.

29. The nonwoven web of claim 23 wherein the acrylate copolymer has an apparent viscosity in the melt in a range of about 150 poise to about 800 poise.

30. The nonwoven web of claim 23 wherein the monofunctional alkyl (meth)acrylate monomer is selected from the group of 2-methylbutyl acrylate, isooctyl acrylate, lauryl acrylate, poly(ethoxylated) methoxy acrylate, and mixtures thereof.

31. The nonwoven web of claim 23 wherein the free-radically copolymerizable reinforcing monomer is a monofunctional (meth)acrylic monomer.

32. The nonwoven web of claim 31 wherein the monofunctional (meth)acrylic reinforcing monomer is selected from the group of an acrylic acid, a methacrylic acid, an acrylate, an acrylamide, and mixtures thereof.

33. The nonwoven of claim 32 wherein the monofunctional (meth)acrylic reinforcing monomer is selected from the group of acrylic acid, N,N-dimethyl acrylamide, 1,1,3,3-tetramethylbutyl acrylamide, 2-hydroxypropyl acrylate, 2-(phenoxy)ethyl acrylate, and mixtures thereof.

34. The nonwoven web of claim 23 wherein the crosslinking agent is copolymerized with the monofunctional alkyl (meth)acrylate monomer and the reinforcing monomer.

35. The nonwoven web of claim 34 wherein the crosslinking agent is selected from the group consisting of an acrylic crosslinking monomer, a polymeric crosslinking material having a copolymerizable vinyl group, and mixtures thereof.

36. The nonwoven web of claim 35 wherein the polymeric material having a copolymerizable vinyl group is selected from the group of a (meth)acrylate-terminated polystyrene macromer and a (meth)acrylate-terminated polymethyl methacrylate macromer.

37. The nonwoven web of claim 23 further comprising fibers selected from the group of thermoplastic fibers, carbon fibers, glass fibers, mineral fibers, organic binder fibers, and mixtures thereof.

38. The nonwoven web of claim 23 further comprising particulate material.

39. The nonwoven web of claim 23 wherein the crosslinking agent forms chemical crosslinks.

40. The nonwoven web of claim 23 wherein the crosslinking agent forms physical crosslinks.

41. The nonwoven web of claim 23 wherein each fiber is in the form of a multilayer fiber comprising at least a first layer comprising an acrylate copolymer.

42. The nonwoven web of claim 41 wherein each fiber further comprises at least a second layer comprising a pressure-sensitive adhesive composition comprising a different acrylate copolymer.

43. The nonwoven web of claim 41 wherein each fiber further comprises at least a second layer comprising a secondary melt processable polymer or copolymer.

44. The nonwoven web of claim 43 wherein the secondary melt processable polymer or copolymer is selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

45. The nonwoven web of claim 44 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.

46. The nonwoven web of claim 43 wherein the secondary melt processable polymer or copolymer is mixed with a tackifier.

47. An adhesive article comprising a backing and a layer of a nonwoven web laminated to at least one major surface of the backing;

wherein the nonwoven web comprises pressure-sensitive adhesive fibers;

wherein the fibers comprise a pressure-sensitive adhesive composition comprising a crosslinked melt-processable acrylate copolymer as a structural component of the fibers;

wherein the crosslinked melt-processable acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer, at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer, and a crosslinking agent;

wherein the crosslinking agent crosslinks subsequent to fiber formation.

48. The adhesive article of claim 47 wherein each fiber is in the from of a multilayer fiber comprising at least a first layer comprising a acrylate copolymer.

49. An adhesive article comprising a backing and a layer of nonwoven web laminated to at least one major surface of the backing;

wherein the nonwoven web comprises pressure-sensitive adhesive fibers;

wherein each fiber is in the form of a multilayer fiber comprising at least a first layer comprising a pressure-sensitive adhesive composition comprising an acrylate copolymer as a structural component of the fibers;

wherein the acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer and at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer.

50. A pressure-sensitive adhesive fiber comprising a pressure-sensitive adhesive composition comprising a crosslinked acrylate copolymer as a structural component of the fiber;

wherein the crosslinked acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer, at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer, and a crosslinking agent;

wherein the crosslinking agent crosslinks subsequent to fiber formation; and

further wherein the pressure-sensitive adhesive composition includes at least one secondary melt processable polymer or copolymer selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

51. The fiber of claim 50 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.

52. A nonwoven web comprising pressure-sensitive adhesive fibers;

wherein the fibers comprise a pressure-sensitive adhesive composition comprising a crosslinked acrylate copolymer as a structural component of the fibers;

wherein the crosslinked acrylate copolymer comprises copolymerized monomers comprising at least one monofunctional alkyl (meth)acrylate monomer, at least one monofunctional free-radically copolymerizable reinforcing monomer having a homopolymer glass transition temperature higher than that of the alkyl (meth)acrylate monomer, and a crosslinking agent;

wherein the crosslinking agent crosslinks subsequent to fiber formation; and

further wherein the pressure-sensitive adhesive composition further includes at least one secondary melt processable polymer or copolymer selected from the group of a polyolefin, a polystyrene, a polyurethane, a polyester, a polyamide, a styrenic block copolymer, an epoxy, a vinyl acetate, and mixtures thereof.

53. The nonwoven web of claim 52 wherein the secondary melt processable polymer or copolymer is a tackified styrenic block copolymer.