Elastic strand laminate

• US 6,967,178 B2
• Filed: 12/26/2002
• Issued: 11/22/2005
• Est. Priority Date: 07/02/2002
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Zhou, Peiguang, Neculescu, Cristian M.
• Primary Examiner(s): Morris, Terrel
• Assistant Examiner(s): Piziali, Andrew T.
• Application Number:
  US10/330,001
• Publication Number:
  US 20040005835A1
• Time in Patent Office: 1,062 Days
• Field of Search: 442/104, 442/149, 442/328, 442/329, 442/382, 442/394, 442/400, 442/401, 428/343, 428/355.R
• US Class Current: 442/149
• CPC Class Codes: A61F 13/15593 having elastic ribbons fixed thereto; Devices for applying the ribbons
• CPC Class Codes: A61F 13/49011 the elastic means is located at the waist region
• CPC Class Codes: A61F 13/49014 the elastic means is located at the side panels
• CPC Class Codes: A61F 13/49017 the elastic means being located at the crotch region
• CPC Class Codes: A61F 13/4902 characterised by the elastic material
• CPC Class Codes: B32B 2305/20 in the form of a non-woven mat
• CPC Class Codes: B32B 2307/51 Elastic
• CPC Class Codes: B32B 25/04 comprising rubber as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/043; next to a bituminous or tarry layer B32B11/044; next to a water setting substance layer B32B13/042; next to a metal layer B32B15/06; next to a glass layer B32B17/063; next to a layer formed of natural mineral fibres or particles B32B19/043; next to a wood layer B32B21/045; next to a cellulosic plastic layer B32B23/046
• CPC Class Codes: B32B 2555/02 Diapers or napkins
• CPC Class Codes: B32B 37/144 using layers with different mechanical or chemical conditions or properties, e.g. layers with different thermal shrinkage, layers under tension during bonding constructional features for tensioning B32B38/1825
• CPC Class Codes: C09J 153/00 Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
• CPC Class Codes: C09J 153/02 Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1002 with permanent bending or reshaping or surface deformation of self sustaining lamina
• 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 428/2852 Adhesive compositions
• CPC Class Codes: Y10T 442/2369 Coating or impregnation improves elasticity, bendability, resiliency, flexibility, or shape retention of the fabric
• CPC Class Codes: Y10T 442/2738 Coating or impregnation intended to function as an adhesive to solid surfaces subsequently associated therewith
• CPC Class Codes: Y10T 442/601 Nonwoven fabric has an elastic quality
• CPC Class Codes: Y10T 442/602 Nonwoven fabric comprises an elastic strand or fiber material
• CPC Class Codes: Y10T 442/66 : Additional nonwoven fabric is a spun-bonded fabric
• CPC Class Codes: Y10T 442/674 : Nonwoven fabric with a preformed polymeric film or sheet
• CPC Class Codes: Y10T 442/68 : Melt-blown nonwoven fabric
• CPC Class Codes: Y10T 442/681 : Spun-bonded nonwoven fabric

Abstract

An elastic strand laminate, and a method of making an elastic strand laminate. The elastic strand laminate includes a plurality of self-adhering elastic strands made up of an elastomeric adhesive composition. The self-adhering elastic strands can be laminated to one or more facing sheets using conventional hot melt equipment.

Claims

1. An elastic laminate, comprising:

at least one facing sheet; and

a plurality of strands of a melt-tank processable elastomeric construction adhesive composition self-adhered to the at least one facing sheet;

the elastomeric adhesive composition including at least 55% by weight of a base polymer selected from the group consisting of polystyrene-polyethylene-polypropylene-polystyrene (SEPS) block copolymer, styrene-isoprene-styrene (SIS) block copolymer, styrene-butadiene-styrene (SBS) block copolymer, thermoplastic polyurethane, ethylene-propylene-diene copolymers, and combinations thereof, and at least 30% by weight of a high softening point tackifier resin comprising at least one type of hydrocarbon selected from the group consisting of petroleum distillates, rosin, rosin esters, polyterpenes derived from wood, polyterpenes derived from synthetic chemicals, and combinations thereof, and having a softening point of at least 80 degrees Celsius and a viscosity of at least 1500 cps at 182 degrees Celsius;

wherein the elastomeric construction adhesive composition has a viscosity of about 5,000 to 80,000 cps at between 177 and 204 degrees Celsius.

2. The elastic strand laminate of claim 1, wherein the plurality of strands are spaced apart on the at least one facing sheet by about 2 to about 6 strands per centimeter.

3. The elastic strand laminate of claim 1, wherein each of the plurality of strands has a diameter between 0.25 and 0.64 centimeter.

4. The elastic strand laminate of claim 1, wherein the at least one facing sheet comprises a nonwoven web selected from a spunbond web and a meltblown web.

5. The elastic strand laminate of claim 1, wherein the at least one facing sheet comprises a film.

6. The elastic strand laminate of claim 1, wherein the base polymer has a melt flow rate between about 5 and about 200 grams per minute, a Shore A hardness between about 20 and about 70, and may be stretched up to about 1300%.

7. The elastic strand laminate of claim 1, wherein the elastomeric adhesive composition further comprises a low softening point additive having a softening point of less than 80 degrees Celsius and a viscosity of less than 1000 cps at 182 degrees Celsius, present in an amount between about 0% and about 20% by weight.

8. The elastic strand laminate of claim 1, wherein the elastomeric adhesive composition further comprises an antioxidant in an amount between about 0.1% and about 1.0% by weight.

9. The elastic strand laminate of claim 1, wherein the composition has a viscosity of about 10,000 to 50,000 cps at between 177 and 196 degrees Celsius.

10. The elastic strand laminate of claim 1, wherein e laminate has a basis weight between about 20 and about 120 grams per square meter.

11. The elastic strand laminate of claim 1, wherein the laminate exhibits a stretch-to-stop ratio of at least 50%.

12. The elastic strand laminate of claim 1, wherein the laminate exhibits a stretch-to-stop ratio of at least 150%.

13. The elastic strand laminate of claim 1, wherein the laminate exhibits a stretch-to-stop ratio of at least 250%.

14. The elastic strand laminate of claim 1, wherein the laminate has tension of at least 100 grams per inch at 100% elongation.

15. The elastic strand laminate of claim 1, wherein the laminate has tension of at least 200 grams per inch at 100% elongation.

16. An elastic laminate, comprising:

a first facing sheet and a second facing sheet; and

a plurality of strands of an elastomeric construction adhesive composition self-adhered between the first facing sheet and the second facing sheet, and spaced apart by about 2 to about 6 strands per centimeter;

the elastomeric adhesive composition including at least 55% by weight of a base polymer selected from the group consisting of polystyrene-polyethylene-polypropylene-polystyrene (SEPS) block copolymer, styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS) block copolymer, thermoplastic polyurethane, ethylene-propylene-diene (EPDM) copolymer, and combinations thereof; and

at least 30% by weight of a high softening point tackifier resin comprising at least one type of hydrocarbon selected from the group consisting of petroleum distillates, rosin, rosin esters, polyterpenes derived from wood, polyterpenes derived from synthetic chemicals, and combinations thereof, and having a softening point of at least 80 degrees Celsius and a viscosity of at least 1500 cps at 182 degrees Celsius;

wherein the elastomeric construction adhesive composition has a viscosity of about 5,000 to 80,000 cps at between 177 and 204 degrees Celsius and the spaced apart strands have diameters of at least 0.25 centimeter.

17. The elastic strand laminate of claim 16, wherein at least one of the first and second facing sheets comprises a nonwoven web selected from a spunbond web and a meltblown web.

18. The elastic strand laminate of claim 16, wherein at least one of the first and second facing sheets comprises a film.

19. The elastic strand laminate of claim 16, wherein the elastomeric adhesive composition further comprises a low softening point additive having a softening point of less than 80 degrees Celsius and a viscosity of less than 1000 cps at 182 degrees Celsius.

20. The elastic strand laminate of claim 16, wherein the elastomeric adhesive composition further comprises an antioxidant in an amount between about 0.1% and about 1.0% by weight.

21. The elastic strand laminate of claim 16, wherein the laminate exhibits less than 10% creep after aging at 38 degrees Celsius for 90 minutes.

22. The elastic strand laminate of claim 16, wherein the laminate exhibits a stretch-to-stop ratio of at least 200%.