Stretch composites and methods of making the composite

• US 20070029035A1
• Filed: 10/06/2006
• Published: 02/08/2007
• Est. Priority Date: 11/05/2001
• Status: Active Grant

• Current Assignee: Fred Desai, Mark Hamersky, Steven W. Smith, Urmish Dalal
• Original Assignee: Fred Desai, Mark Hamersky, Steven W. Smith, Urmish Dalal
• Inventors: Desai, Fred, Dalal, Urmish, Smith, Steven, Hamersky, Mark
• Granted Patent: US 8,480,840 B2
• Time in Patent Office: Days
• US Class Current: 156/277
• CPC Class Codes: A61F 13/15593 having elastic ribbons fixed thereto; Devices for applying the ribbons
• CPC Class Codes: A61F 13/4902 characterised by the elastic material
• CPC Class Codes: A61F 2013/15284 characterized by quantifiable properties
• CPC Class Codes: B29C 55/08 transverse to the direction of feed
• CPC Class Codes: B29C 55/18 by squeezing between surfaces, e.g. rollers
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 53/025 modified
• CPC Class Codes: D06N 3/045 with polyolefin or polystyrene (co-)polymers
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/2481 including layer of mechanically interengaged strands, strand-portions or strand-like strips
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/269 including synthetic resin or polymer layer or component

Abstract

A stretch composite having one or more elastomeric members disposed on at least one region of an extensible fibrous substrate to provide stretch properties to a targeted region of the substrate. The composite has been incrementally stretched to at least partially break up the structure of the substrate in order to reduce its resistance to stretch. The stretch composites are useful for disposable and durable articles, such as disposable absorbent articles including diapers, pull-on diapers, training pants, incontinence briefs, catamenial garments, baby bibs, and the like, and durable articles like garments including sportswear, outerwear and the like. The present invention also relates to methods of forming such stretch composites.

Claims

1. A process for making a stretch composite from an extensible substrate, said process comprising the steps of:

a. providing a first extensible substrate;

b. providing an application device, said device including at least one patterned print roll;

c. printing one or more elastomeric compositions by means of said patterned print roll, said compositions having a melt viscosity of from about 1 to about 150 Pa·

s, measured at 175°

C. and 1 s<sup>−

1</sup> strain rate, an elasticity of at least about 50 N/m at 20°

C., and a stress relaxation of less than about 20%, onto said substrate thereby forming one or more intermediate structures; and

d. incrementally stretching one or more portions of the intermediate structures to permanently elongate the substrate in the portions.

2. The process of claim 1 wherein said process further comprises after printing a step of converting the elastomeric compositions into elastomeric members.

3. The process of claim 2 wherein the converting comprises one or more processes selected from the group consisting of crosslinking, curing, cooling, pressing, and combinations thereof.

4. The process of claim 1 wherein the elastomeric compositions have a percent set of less than about 20%.

5. The process of claim 4 wherein the thermoplastic elastomer is selected form the group consisting of styrenic block copolymers, metallocene-catalyzed polyolefins, polyesters, polyurethanes, polyether amides, and combinations thereof;

and the phase change solvent has the following formula;

(I) R′

-L_y-(Q-L_x)<sub>n−

1</sub>-Q-L_y-R;

(II) R′

-L_y-(Q-L_x)_n-R;

(III) R′

-(Q-L_x)_n-R;

(IV) R′

-(Q-L_x)<sub>n−

1</sub>-Q-L_y-R;

(V) R′

-(Q-L_x)<sub>n−

1</sub>-Q-R;

or

a mixture thereof;

wherein Q may be a substituted or unsubstituted difunctional aromatic moiety;

L is CH₂;

R and R′

are the same or different and are independently selected from H, CH3, COOH, CONHR₁, CONR₁R₂, NHR₃, NR₃R₄, hydroxy, or C1—

C30 alkoxy;

wherein R₁, R₂, R₃ and R₄ are the same or different and are independently selected from H or linear or branched alkyl from C1—

C30;

x is an integer from 1 to 30;

y is an integer from 1 to 30; and

n is an integer from 1 to 7.

6. The process of claim 1 wherein the incrementally stretched portion of the stretch composite exhibits the following properties in at least one direction:

a directional elasticity of from about 5 N/m to about 400 N/m;

a directional percent set of less than about 20%; and

a directional stress relaxation of less than about 30% after 2 minutes at room temperature and 75% strain.

7. The process of claim 1 wherein the composite comprises one or more elasticized regions of an absorbent article.

8. The process of claim 7 wherein the one or more elasticized regions of the absorbent article is selected from the group consisting of an elasticized waist region, an elasticized cuff region, an elasticized side panel, an elastic ear portion, an elasticized outercover, an elasticized topsheet, a fastener system, and combinations thereof.

9. The process of claim 1 wherein prior to incremental stretching said process further comprises a step of laminating a second substrate to the first extensible substrate with the one or more elastomeric members sandwiched between the first and second substrates.

10. The process of claim 2 wherein the elastomeric members are different in a characteristic selected from the group consisting of compositions, add-on levels, shape, pattern, and combinations thereof.

11. The process of claim 2 wherein the elastomeric members are rectilinear or curvilinear, and at least two of the elastomeric members are non-parallel with respect to each other.

12. The process of claim 7 wherein the one or more elasticized regions are adjacent or at least partially overlapping.