Paper and paper articles and method for making same

• US 20060231227A1
• Filed: 05/14/2003
• Published: 10/19/2006
• Est. Priority Date: 01/26/2000
• Status: Abandoned Application

• Current Assignee: International Paper Company
• Original Assignee: International Paper Company
• Inventors: Williams, Richard C., Froass, Peter M.
• Application Number:
  US10/437,856
• Publication Number:
  US 20060231227A1
• Time in Patent Office: Days
• US Class Current: 162/158
• CPC Class Codes: D21H 21/54 being spherical, e.g. microcapsules, beads
• CPC Class Codes: Y10T 428/27 Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]

Abstract

This invention relates to a paper material containing cellulosic fibers and from about 0.1 to about 6.0 wt % by weight dry basis expandable microspheres and a density of at least about 6.0 lb/3000 ft²/mil and articles formed there from such as file folders.

Claims

1-36. -36. (canceled)

37. A paper material for use in the manufacture of paper articles, comprising a web of cellulosic fibers and from about 0.1 to about 6 wt % based upon a total weight of the web on a dry basis of expanded microspheres, the paper web having a density equal to or greater than 7.5 lb/3000 ft²/mil;

a caliper after calendaring of from about 3 mils to about 25 mils.

38. The paper material according to claim 37, wherein the paper web has a density of from about 6.0 lb/3000 ft²/mil to about 13.0 lb 3000 ft²/mil.

39. The paper material according to claim 37, wherein the paper web has a caliper after calendaring of from about 3.0 to about 14.0 mils.

40. The paper material according to claim 37, comprising from about 0.25 to about 5.0 wt. % based upon a total weight of the web on a dry basis of expanded micro spheres.

41. The paper material according to claim 37, comprising from 0.5 to about 3.0 wt. % based upon a total weight of the web on a dry basis of expanded microspheres.

42. The paper material according to claim 37, wherein the expanded microspheres in the paper web comprises synthetic polymeric microspheres.

43. The paper material according to claim 37, wherein the paper web has a basis weight of from about 20 lb/3000 ft² to about 300 lb/3000 ft².

44. The paper material according to claim 37, wherein the paper web has a basis weight of from about 20 lb/3000 ft² to about 200 lb/3000 ft².

45. The paper material according to claim 37, wherein the paper web has a basis weight of from about 28 lb/3000 ft² to about 180 lb/3000 ft².

46. The paper material according to claim 37, wherein the expanded microspheres in the paper web comprise microspheres made from at least one polymeric material selected from the group consisting of methyl methacrylate, ortho-chlorostyrene, polyortho-chlorostyrene, polyvinylbenzyl chloride, acrylonitrile, vinylidene chloride, para-tert-butyl styrene, vinyl acetate, butyl acrylate, styrene, methacrylic acid, and vinylbenzyl chloride.

47. The paper material according to claim 37, wherein the fibers in the paper web comprise from about 30 to about 100% by weight dry basis softwood fibers, from about 70 to about 0% by weight dry basis hardwood fibers and 0 to about 50% by weight dry basis post consumer waste.

48. The paper material according to claim 37, wherein the microspheres have an expanded diameter of up to about 60 microns.

49. The paper material according to claim 37, wherein the web has been calendered in a calendaring apparatus having one or more nips where the pressure at any nip is not more than about 350 lbs/lineal inch.

50. The paper material according to claim 49, wherein said pressure is equal to or less than about 280 lbs/lineal inch.

51. The paper material according to claim 49, wherein said pressure is equal to or less than about 250 lbs/lineal inch.

52. The paper material according to claim 49, wherein said pressure is equal to or less than about 100 lbs/lineal inch.

53. The paper material according to claim 49, wherein said pressure is equal to or less than about 50 lbs/lineal inch.

54. The paper material according to claim 37, wherein the paper material comprises at least one reverse die cut edge.

55. The paper material according to claim 37, wherein the paper material comprises at least one reverse die cut edge which exhibits an improved resistance to inflicting cuts upon human skin than does a paper material that is the same except that it does not contain expanded microspheres and does not have a density at least 7.5 lb/3000 ft2/mil.

56. The paper material according to claim 55, wherein the paper material exhibits a Cutting Index of less than about 40 when analyzed according to the Cutting Index 30 test.

57. The paper material according to claim 37, wherein the paper material exhibits a Cutting Index of less than about 40 when analyzed according to the Cutting Index 30 test.

58. The paper material of claim 37, wherein the paper material exhibits a GM Fold equal to or great than about 200.

59. The paper material according to claim 58, wherein the GM Fold is equal to or greater than about 350.

60. The paper material according to claim 58, wherein the GM Fold is equal to or greater than about 450.

61. The paper material according to claim 37, wherein said paper material exhibits a higher GM Fold than does a paper material that is the same except that it does not contain from about 0.1 to about 6 wt % based upon a total weight of the web on a dry basis expanded microspheres and does not have a density at least 7.5 lb/3000 ft²/mil.

62. The paper material according to claim 37, wherein said paper material exhibits a GM Fold substantially the same as that exhibited by a second paper material which is substantially the same as said paper material except it does not contain from about 0.1 to about 6 wt % based upon a total weight of the web on a dry basis expanded microspheres and has a basis weight that is 5% greater than the basis weight of said paper material.

63. A method for making the paper material according to claim 37, comprising

providing a papermaking furnish containing cellulosic fibers and from about 0.1 to about 6 wt % by weight dry basis expanded or expandable microspheres;

forming a fibrous web from the papermaking furnish;

drying the web; and

calendering the web to a caliper of from about 3 to about 25 mils and a density equal to or greater than 7.5 lb/3000 ft²/mil.

64. An article of manufacture having a body formed from the paper material according to claim 37.

65. The article according to claim 64, wherein said body comprises a substantially planar first portion and a substantially planar second portion, said first portion and second portion connect along a fold line and are capable of flexing along said line.

66. The paper material according to claim 37, wherein the paper web has a basis weight that is equal to or greater than about 90 lb/3000 ft².

67. The paper material according to claim 37, wherein the paper web has a basis weight of from about 90 lb/3000 ft² to about 300 lb/3000 ft².

68. The paper material according to claim 37, wherein the paper web has a basis weight of from about 100 lb/3000 ft² to about 300 lb/3000 ft².

69. The paper material according to claim 37, wherein said paper web has a caliper after calendaring of from about 7 to about 18 mils.

70. The paper material according to claim 37, wherein said paper web has a caliper after calendaring of from about 8 to about 14 mils.

71. The paper material according to claim 37, wherein said paper web has a caliper after calendaring of from about 9 to about 12 mils.

72. The paper material according to claim 37, wherein said paper web has a caliper after calendaring of from about 10 to about 11.5 mils.