MXPA01006480A - Elastic composite member and disposable garment using the same - Google Patents

Abstract

The present invention is directed to an elastic composite member which is elastically extensible in at least one direction. The elastic composite member comprises a plane elastomeric material having a plurality of apertures formed therein;and a fibrous material including entanglement fibers. The entanglement fibers are hydroentangled with the plane elastomeric material through the apertures. The fibrous material has a Strain Resistance (SRE) of less than about 100%at 100%elongation in the extensible direction. The present invention is also directed to a disposable article including the elastic composite member.

Description

ELASTIC COMPOSITE MEMBER AND DISPOSABLE GARMENT THAT USES THE SAME FIELD OF THE INVENTION The present invention relates to composite elastic members. More specifically, the present invention relates to composite elastic members that include entanglement fibers entangled with an elastomeric material. The present invention also relates to disposable articles using said composite elastic members. Examples of these disposable articles include sweat bands, bandages, body wraps, disposable undergarments, disposable garments including draining diapers and training pants, and disposable panties for menstrual use.

BACKGROUND OF THE INVENTION Elastic members such as elastic laminates and composite elastic members have previously been used in a variety of disposable articles, including sweat bands, bandages, body wraps, and disposable garments including disposable diapers and incontinence devices. Said elastic members typically include at least one elastomeric material and a fibrous material bonded to or combined with the elastomeric material. It is generally expected that these products provide a good fit to the body and / or skin of the user using suitable elastic members during the period of total use of the products.

Those elastic laminates typically include, at least, an elastomeric material and a fibrous material (e.g., a non-woven fabric) bonded to the elastomeric material. In such elastic laminates these materials are typically bonded together through an adhesive bond (or glue) or a heat / pressure bond formed therebetween. The adhesives are frequently used to form elastic laminates. However, the use of such adhesives tends to cause various problems in their manufacturing process and their use by consumers. For example, a manufacturing process that includes an adhesive application tends to become more complicated than one that does not need it (for example, a heat / pressure bonding process). In addition, the application of adhesive tends to cause a contamination problem in manufacturing equipment or production lines. In addition, an elastic laminate using an adhesive tends to cause a problem of odor to the consumers of the disposable products, since some adhesive materials tend to have an unpleasant odor. A heat / pressure joint is also used to form the elastic laminates. For example, Japanese Patent Laid-open Publication (Kokai) No. H10-165437 published June 23, 1998 discloses a disposable diaper that includes a three-layer structure of non-woven elastomeric film / non-woven material that are bonded together together through a number of discontinuous points of union. However, this structure tends not to provide sufficient bond strength in the layered structure against an effort that is generated in the use of the disposable articles (or which can be applied in the manufacturing process thereof), thus causing a separation of the materials in layers. It is believed that this problem is caused because the layered structure does not have a sufficient bond strength required by the disposable articles.

Composite elastic members that include entanglement fibers entangled with an elastomeric material are known in the art. Examples of said composite elastic members are disclosed in, for example, the patent of the United States No. 4,775,579 entitled "Elastic and non-elastic hydroentangled filaments" issued to Hagy et al. On October 4, 1998; and in the patent of the United States No. 5,334,446 entitled "Composite elastic non-woven fabric" issued to Quantrille et al. On August 2, 1994. Since the entangling fibers are hydroentangled with the elastomeric material (ie, the entangled fibers do not form a layered structure), the composite members can more easily avoid the problem of separation caused by the efforts generated in the use of the disposable articles, compared with the elastic laminates. However, those composite members tend to be less stretchable since the entanglement fibers tend to reduce the ability of the elastomeric material to elongate. This tends to spoil the expected performance of disposable articles (e.g., an elastic stretch ability). An example of disposable items is a disposable garment. Babies and other incontinent individuals wear disposable garments such as diapers to receive and contain urine and other exudates from the body. These disposable garments often use an elastic member. For example, the ear panels and / or the waistbands of the disposable garments preferably include an elastic member. The operation of the elastic member is important since the ear panels and / or the waistbands contribute to providing a better notch to the user's waist area. In the disposable garments that stretch, in particular, the operation of the elastic member also tends to impact an ease of application. For example, if the elastic elongation capacity of the ear panels and / or waistbands is very limited, the user who wants to apply the stretched garment has (or at least feels) a difficulty in forming an appropriate size of the opening of the garment. waist by fingers. Examples of stretched garments are disclosed, for example, in U.S. Patent No. 5,171, 239 to Igaue et al., U.S. Patent No. 4,610,681 to Strohbeen et al., Published international publication WO 93/17648. on September 16, 1993; United States Patent No. 4,940,464 of Van Gompel et al., U.S. Patent No. 5,246,433 to Hasse et al., And U.S. Patent No. 5,569,234 to Buell et al. Based on the foregoing, there is a need for composite elastic members that have a minimal influence by the entanglement fibers on the elongation capacity. There is also a need for disposable articles that use such composite elastic members.

BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to a composite elastic member that is elastically extensible in at least one direction. The composite elastic member comprises an elastomeric flat material having a plurality of openings formed therein; and a fibrous material that includes entanglement fibers. The entangling fibers are hydroentangled with the elastomeric flat material through the openings. The fibrous material has a resistance to stress (SRE) less than about 100% at 100% elongation in the tensile direction. The present invention is also directed to a disposable article that includes the composite elastic member. The above responds to the need for composite elastic members that have a minimal influence by the entanglement fibers on the elongation capacity. The foregoing also responds to the need for disposable garments using said composite elastic members. These and other features, aspects and advantages of the present invention will become apparent to those skilled in the art from the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims singling out and claiming the invention differently, it is believed that the invention will be better understood from the following description of the preferred embodiments which are taken in combination with the accompanying drawings, and in which like designations are used to designate substantially identical elements, and in which: Figure 1 is a perspective view of an elastomeric flat material employed in the preferred embodiments of the present invention. Figure 2 is a graph showing an example of the cycles of the hysteresis curves of the elastomeric flat material in a preferred embodiment. Figure 3 is a perspective view of a composite elastic member that is a preferred embodiment of the present invention. Figure 4 is a perspective view of a composite elastic member that is another preferred embodiment of the present invention. Figure 5 is a schematic representation of a pressure applying device for forming the flattened composite elastic member. Figure 6 is a perspective view of a disposable garment embodiment of the invention present in a typical configuration of use.

Figure 7 is a perspective view of another preferred embodiment of the disposable garment of the invention present in a typical configuration of use. Figure 8 is a simplified plan view of the embodiment shown in Figure 7 in its flat condition without contracting showing the various panels or areas of the garment. Figure 9 is a cross-sectional view of a preferred embodiment taken along section line 9-9 of Figure 8. Figure 10 is a cross-sectional view of a waistband 50 of a preferred embodiment taken as shown in FIG. length of the section line 10-10 of Figure 8. Figure 1 1 is a cross-sectional view of a waistband 50 of another preferred embodiment. Figures 12 and 13 are schematic diagrams explaining the test method for measuring the values of the surface roughness of the composite elastic members. Figure 14 is a cross-sectional view of a steel plate used to measure the values of the surface roughness of the composite elastic members. Figure 15 is a graph showing a deviation of the surface of the composite elastic members obtained by a measurement.

DETAILED DESCRIPTION All references cited are incorporated herein by reference in their totalities. The citation of any reference is not an admission with respect to any determination as to its availability as a prior art for the claimed invention.

Here, "understand" means that you can add other elements and steps or steps that do not affect the final result. These terms encompass the terms "consisting of" and "consisting essentially of". Here, "elastomeric flat material" refers to elastomeric materials that extend continuously in two dimensional directions. The elastomeric flat material has a first surface and a second surface opposite the first surface. Here, "extensible" and "stretchable" refers to materials that are capable of extending in at least one direction to a certain degree without undue rupture. Here, "elasticity," "elastically extensible," and "elastically stretchable" refer to extensible or extensible materials that have the ability to return to approximately their original dimensions after the force that extended to the material is removed. Here, "disposable" describes garments that are not intended to be washed or restored or reused in another way as a garment (ie, they are intended to be discarded after a simple use and, preferably, to be recycled, formed in compost, or otherwise disposed of in an environmentally compatible way). Here, "stretchy garment" refers to articles of use that have a defined waist opening and a pair of leg openings and which are placed on the wearer's body by inserting the legs into the leg openings and pulling the leg. item up on the waist. Here, "stretching diaper" refers to stretched garments usually worn by babies and other incontinent individuals to absorb and contain urine and feces. However, it should be understood that the present invention is also applicable to other stretchy garments such as training pants, incontinence briefs, garments or panties for feminine hygiene, and the like. Here, "panel" means an area or item of the garment that stretches. (Although a panel is typically a different area or element, a panel can match (functionally correspond) a bit with an adjacent panel.) Here, "joined" or "linking" encompasses configurations by which one element is directly secured to another element for fixing the element directly to the other element, and configurations by which the element is indirectly secured to the other element by fixing the element to a member or intermediate members which in turn are fixed to the other element. Here, "state without contracting" is used to describe the states of the garments that stretch in their condition without seams (ie, the seams are removed), flat and relaxed where all the elastic materials used are removed from them. Figure 1 is a perspective view of an elastomeric flat material 520 used in a preferred embodiment of the present invention. The elastomeric flat material 520 has a first surface 401 and a second surface 402 opposite the first surface 401. The elastomeric flat material 520 of the present invention has a plurality of openings 530 formed therein. The openings 530 formed in the elastomeric flat material 520 can be of any shape and size while the entangling fibers can be hydroentangled with the elastomeric flat material 520 through the openings 530. Preferred shapes of the openings 530 include a circle, an ellipse, a triangle, a quadrilateral including a rectangle, a square and a trapezoid, and other polygons. In a preferred embodiment, the average opening area of an opening 30 is from about 1 mm2 to about 25 mm2, more preferably from about 3 mm2 to about 10 mm2. Preferably, the ratio of the total area of the openings 530 in the first surface 401 (for example) to the surface area of the first surface 401 is from about 10% to about 90%, more preferably from about 40% to about 60. %. The elastomeric flat material 520 can take any form that can be adequately provided in the products. Preferred forms of an elastomeric flat material 520 include a quadrilateral including a rectangle and a square, a trapezoid, or other polygons. The elastomeric flat material 520 of the present invention is elastically extensible in at least one direction (first direction). For example, the elastomeric flat material 520 shown in Figure 1 is elastically extensible in the structural direction D. Here, "structural direction" (eg, D and B) is intended to mean a direction extending substantially along and parallel to the plane of the elastomeric flat material 520. In a preferred embodiment, the elastomeric flat material 520 is also elastically extensible in the second direction that is perpendicular to the first direction. The direction having the greatest elongation capacity in the plane of the elastomeric flat material 520 is hereinafter referred to as the "primary extensible direction". In a preferred embodiment, the elastomeric flat material 520 shown in Figure 1 has the primary extensible direction in the structural direction D. The elastomeric material used in the elastomeric flat material can include all suitable elastic materials known in the art. Suitable elastomeric materials for use herein include natural synthetic rubber materials known in the art. Preferred elastomeric materials include two-block or three-block copolymers based on polystyrene and unsaturated or fully hydrogenated rubber blocks, and mixtures thereof with other polymers such as polystyrene polymers. In a preferred embodiment, the elastomeric material contains from about 30% by weight to about 95% by weight of polystyrene, more preferably from about 50% by weight to about 85% by weight of polystyrene. Preferably, the elastomeric material is made from a thermoplastic polystyrene elastomer that includes materials based on styrene block copolymer. Preferred styrene block copolymer-based materials comprise from about 1% by weight to about 70% by weight of polystyrene, more preferably from about 10% by weight to about 50% by weight of polystyrene. A preferred polystyrene thermoplastic elastomer is selected from the group consisting of a styrene-butadiene-styrene thermoplastic elastomer, a styrene-isoprene-styrene thermoplastic elastomer, a styrene-ethylene / butylene-styrene thermoplastic elastomer, a thermoplastic elastomer of styrene-ethylene / propylene-styrene, an unsaturated styrene butadiene rubber or a fully hydrogenated styrene butadiene rubber, a mixture thereof, and mixtures thereof with other polymers such as polyethylene polymers. In a preferred embodiment, the elastomeric flat material 520 has a basis weight of from about 30 g / m2 to about 250 g / m2, preferably from about 60 g / m2 to about 200 g / m2, and more preferably of about 100 g / m2 at approximately 160 g / m2. In one embodiment, the elastomeric flat material 520 is a perforated film (not shown in the Figures) formed by an elastomeric material. The perforated film has a multiplicity of apertures 530 formed therein. In a preferred embodiment, the elastomeric flat material 520 is in the form of a canvas as shown in Figure 1.

Figure 1 shows an elastomeric canvas 560 which is employed in the preferred embodiments of the present invention. The elastomeric canvas 560 includes a plurality of first strings 125 that intersect or traverse (with or without joining a) a plurality of second strings 127 at the nodes 128 at a predetermined angle a, thereby forming an open network-like structure having a plurality of openings 530. Each opening 530 is defined by at least two adjacent first cords 125 and at least two adjacent second cords 127 so that the openings 530 are substantially rectangular in shape. Other aperture configurations, such as parallelograms or circular arc segments, may also be provided. Said configurations may be useful to provide nonlinear elastic structural directions. Preferably, the first cords 125 are substantially straight and substantially parallel to one another; and, more preferably, the second ropes 127 are also substantially straight and substantially parallel to one another. More preferably, the first cords 125 intersect the second cords 127 and the nodes 128 at a predetermined angle a of about 90 degrees. Each node 128 is an overlapped node, wherein the first chords 125 and the second chords 127 are preferably joined or linked (although it is contemplated that the link or link may not be required) at the point of intersection with the chords still distinguishable individually in the nodes 128. However, it is believed that other node configurations such as merged or a combination of merged and superimposed would be equally suitable. Although it is preferred that the first and second chords 125 and 127 be substantially straight, parallel, and intersect at an angle a of about 90 degrees, it is noted that the first and second chords 125 and 127 may intersect other angles, and that the first cords 125 and / or second cords 127 may be aligned in circular, elliptical or non-linear patterns in another way relative to one another. Although for ease of manufacture it is contemplated that the first chords 125 and the second chords 127 have a substantially circular cross-sectional shape (prior to the application of a pressure to form a flattened composite elastic member as shown in Figure 5), the first and second cords 125 and 127 may also have other cross-sectional shapes such as ellipticals, squares, triangles or combinations thereof. Preferably, the material for the first strings 125 is chosen so that the first strings 125 can maintain the second strings 127 in relative alignment before the formation of a composite elastic member. It is also desirable that the materials for the first and second cords 125 and 127 be capable of being deformed (or formed initially) in predetermined ways upon application of a predetermined pressure or pressure in combination with a heat flow before forming a compound elastic member. These deformed shapes (eg, elliptical second strings, substantially flat first strings and the like) can provide a composite elastic member which can be comfortably worn around the body without irritation or other discomfort. In a preferred embodiment, the first cords 125 of the elastomeric canvas 560 have an average cross-sectional area of about 0.0001 mm2 to about 0.5 mm2, and the second cords 127 have an average cross-sectional area of about 0.01 mm2 to about 2.5 mm2. More preferably, the first cords 125 have an average cross-sectional area of about 0.0025 mm2 to about 0.1 mm2, and the second cords 127 have an average cross-sectional area of about 0.1 mm2 to about 1 mm2.

In a preferred embodiment, the elastomeric canvas 560 has from about 5 to about 20 elastic cords per inch (about 2 to 8 cords / cm) in the structural direction B (i.e., the first cords 125) and from about 3 to about 15 cords. elastic cords per inch (approximately 1 to 6 cords / cm) in the structural direction D (i.e., the second cords 127), More preferably, the elastomeric canvas 560 has from about 10 to about 15 elastic cords per inch (about 4) at 6 cords / cm) in the structural direction B and from about 5 to about 10 elastic cords per inch (about 2 to 4 cords / cm) in the structural direction D. In a preferred embodiment, the first and second cords 125 and 127 are formed from an identical elastomeric material. For example, the first and second cords 125 and 127 are formed from an identical polystyrene thermoplastic elastomer which is selected from the group consisting of a styrene-butadiene-styrene thermoplastic elastomer, a styrene-isoprene thermoplastic elastomer. -styrene, a styrene-ethylene / butylene-styrene thermoplastic elastomer, a styrene-ethylene / propylene-styrene thermoplastic elastomer, a fully hydrogenated styrene butadiene rubber or an unsaturated styrene butadiene rubber, and their blends with other polymers such as polystyrene polymers. A preferred elastomeric web 124 containing a styrene-butadiene-styrene thermoplastic elastomer is manufactured by Conwed Plastics Company (Minneapolis, Minn., USA) under the designation XO2514. This material also has approximately 12 elastic cords per inch (about 5 cords / cm) in the structural direction B (ie, the first cords 125) and about 7 elastic cords per inch (about 3 cords / cm) in the structural direction D (ie, the second strings 127).

Alternatively, the first and second cords 125 and 127 are formed from two different materials. For example, one of the first and second cords 125 and 127 is formed from one of the polystyrene thermoplastic elastomers described above, while the other of the first and second cords 125 and 127 is formed from the material or materials different from the thermoplastic polystyrene elastomer described above. Said other material or materials can be either elastic or non-elastic and selected from suitable materials known in the art. Figure 2 shows a preferred example of the extension and recovery force curves for the hysteresis of two cycles of the elastomeric flat material 520 (for example, an elastomeric canvas 560). Curve E1 shows the extension force in the first cycle, while curve R1 shows the recovery force in the first cycle. Curve E2 (shown in dotted lines) shows the extension force in the second cycle, while curve R2 shows the recovery force in the second cycle. (The extension and recovery properties are measured as follows: In the first cycle, the elastomeric flat material 520 is subjected to an initial extension force at a crosshead speed of approximately 51 cm / min (approximately in / min) at approximately 23 ° C and maintained for 20 seconds at 200% extension. The elastomeric flat material 520 is then allowed to relax at the same speed to the original state (ie, 0% extension). The elastomeric flat material 520 is allowed to remain unrestricted for one minute before being subjected to a second extension force (for the second cycle) at the same speed and conditions. Figure 3 is a perspective view showing an elastic member composed of a preferred embodiment of the present invention. Referring to the Figure 3, the composite elastic member 500 includes the elastomeric flat material 520 having the openings 530 (not shown in Figure 3 but in Figure 1), and a fibrous material 540 including the entanglement fibers 550. The entangling fibers 550 they are hydroentangled one to another and with elastomeric flat material 520 through the openings 530. The entangling fibers 550 are represented only in a part of the composite elastic member 500 in Figure 3 (and also in Figure 4). The composite elastic member 500 has a first surface 501 and a second surface 502 opposite the first surface 501. In a preferred embodiment, the elastomeric flat material 520 is an elastomeric canvas 560 as shown in Figure 1. In the embodiment shown in Figure 3, the first surface 501 of the composite elastic member 500 has lug portions 51 1 which are uplifted by the first cords 125, and lug portions 512 that are uplifted by the second cords 127. Similarly, the second one surface 502 of the composite elastic member 500 also has superslipping portions (not shown in Figure 3) which are uplifted by the first and second cords 125 and 127. The composite elastic member 500 of the present invention is elastically extensible at minus one address (first address). For example, the composite elastic member 500 shown in Figure 3 is elastically extensible in the structural direction D. In a preferred embodiment, the composite elastic member 500 is also elastically extensible in the second direction which is pedendicular to the first direction. For example, the composite elastic member 500 shown in Figure 3 is also elastically extensible in the structural direction B. In a preferred embodiment, the composite elastic member 500 shown in Figure 3 has the primary extensible direction in the structural direction D. Tangle fibers 550 are hydroentangled one to another. The entanglement fibers 550 are also hydroentangled with the elastomeric flat material 520 through the openings 530. Such a structure of the entangling fiber can be formed by any fiber hydroentanglement process known in the art. Preferred hydroentangling processes are described in, for example, U.S. Patent No. 4,775,579 entitled "Hydro-entangled elastic and non-elastic filaments" issued Hagy et al. On October 4, 1988; and in U.S. Patent No. 5,334,446 entitled "Compound non-woven elastic fabric" issued to Quantrille et al. on August 2, 1994. In a preferred embodiment, the entangling fibers 550 are hydroentangled to each other uniformly in the adjacent openings 530 of the elastomeric flat material 520. Here, "uniformly" is used to describe the hydroentangled fibers disposed in the adjacent openings which have substantially the same in terms of the average void volume of the fibrous material formed by the entanglement fibers . Here, "substantially the same" means the deviation of the physical quantity (e.g., hollow volume) of a material that is within about 40%, more preferably about 20% of the total amount. In a preferred embodiment, the fibrous material 540 has a basis weight of about 5 g / m2 to about 100 gm / 2, more preferably from about 20 g / m2 to about 80 g / m2, and still more preferably about 30 g / m2. g / m2 at approximately 60 g / m2. Any type of fibers can be used for the entanglement fibers 550 of the present invention. For example, natural fibers (e.g., wood or cotton fibers), synthetic fibers (e.g., polyolefin, polyester, nylon and rayon fibers), or a mixture of natural and / or synthetic fibers that can be used as Tangle fibers. For ease of manufacturing and cost efficiency, the cut synthetic fibers are preferably used. More preferably, said cut synthetic fibers are formed from a polyolefin (for example, polyethylene and polypropylene) or a polyester. The preferred polyester material includes a polyethylene terephthalate, a polypropylene terephthalate and a polybutylene terephthalate, or mixtures thereof. In one embodiment, the individual entanglement fibers 550 are formed from a simple material that is selected from the above materials (ie, the individual fiber is not made of two or more materials). Alternatively, the entanglement fibers 550 can be formed from a mixture of two (or more) materials that are selected from the above materials. In a preferred embodiment, the entanglement fibers 550 are fibers of two components. Preferably, the entangling fibers 550 have a two-component fiber structure formed of two different materials, for example, a side-to-side cross section or an eccentric cross-section. In a preferred embodiment, the two-component fibers have a side-by-side cross section of a low molecular weight polyethylene terephthalate and a higher molecular weight polyethylene terephthalate. In a preferred alternative embodiment, the two component fibers have an eccentric cross section of a polypropylene and a polypropylene / polyethylene random copolymer which preferably contains less than 15% polyethylene. Preferably, the entanglement fibers 550 have an average fiber thickness of less than about 4 denier per filament. More preferably, the entanglement fibers 550 have an average fiber thickness greater than about 0.5 denier per filament. Still more preferably, the entanglement fibers 550 have an average fiber thickness of about 1 to about 2.5 denier per filament. In a preferred embodiment, the entanglement fibers 550 have an average fiber length of about 1 cm to about 10 cm. More preferably, the entangling fibers 550 have an average fiber length of about 3 cm to up to about 7 cm. Still more preferably, the entangling fibers 550 have an average fiber length of about 4 cm to about 6 cm. In a preferred embodiment, the composite elastic member 500 has a tension at 100% elongation of about 20 gf / cm to about 200 gf / cm, preferably about 60 gf / cm to about 140 gf / cm, and more preferably from approximately 80 gf / cm to approximately 120 gf / cm. The fibrous material 540 of the present invention has a tensile strength (SRE) less than about 100% to 100% elongation in the extensible direction. In the embodiment shown in Figure 3, the extendable address can be any of the structure address D or B (preferably, D). The SRE is a physical property of the entanglement fibers (i.e., a fibrous material) which are hydroentangled one to another and with an elastomeric flat material in a composite elastic member. The SRE of a fibrous material at an elongation designated in the extensible direction is obtainable from the following expression: SRE = (TSC - TSE) / TSE x 100 (%) where, TSC: average tensile strength of the composite elastic member at the designated elongation; and TSE: average tensile strength of the elastomeric flat material at the designated elongation.

The SRE value shows a degree of strength of the fibrous material when the elastic composite member is elongated to a designated elongation (eg, 100% of the original length) especially in the first several times before using the disposable articles. For example, a fibrous material 540 which has a relatively higher SRE value requires a relatively higher force to elongate the composite elastic member. Said fibrous material 540 tends to spoil an expected performance of the disposable articles using the composite elastic member. A method for measuring the tensile strength of composite elastic members and elastomeric flat materials is described in the "Test Methods" section. In a preferred embodiment, the fibrous material 540 has an SRE less than about 60%, and more preferably less than about 30% to 100% elongation in the extensible direction. In a preferred alternative embodiment, the fibrous material 540 has an SRE less than about 30%, and more preferably less than about 20% to 50% elongation in the extensible direction. Preferred composite elastic members 500 are obtainable from Daiwabo Co., Ltd., Osaka, Japan, under code numbers PC160A; PC160B; PC170B and PC170C. The fibrous materials 540 of these composite elastic members 500 have the values of the SRE following 50% and 100% elongation in the cross machine direction (CD).

Table I Figure 4 is a perspective view of a composite elastic member 600 which is another preferred embodiment of the present invention. Referring to Figure 4, the composite elastic member 600 includes the elastomeric flat material 520 having the openings 530 (not shown in Figure 4), and a fibrous material 540 including the entanglement fibers 550. The entanglement fibers 550 are hydroentangled one another and with the elastomeric flat material 520 through the openings 530. The entangling fibers 550 are represented only in a part of the composite elastic member 600. The composite elastic member 600 has a first surface 501 and a second surface 502 opposite to the first surface 501. In a preferred embodiment, the elastomeric flat material 520 is an elastomeric canvas 560 as shown in Figure 1. Compared to the embodiment shown in Figure 3, the elastic composite member 600 has lower portions. of rising 51 1 'and 512' which are uplifted by the first and second cords 125 and 127 on the first and second surfaces 501 and 502. The composite elastic member 600 is elastically extensible in at least one direction (first direction). For example, the composite elastic member 600 shown in Figure 4 is elastically extensible in the structural direction D. In a preferred embodiment, the composite elastic member 600 is also elastically extensible in the second direction which is perpendicular to the first direction. For example, the composite elastic member 600 shown in Figure 4 is also elastically extensible in the structural direction B. In a preferred embodiment, the composite elastic member 600 shown in Figure 4 has the primary extensible direction in the structural direction D. In the embodiment shown in Figure 4, the composite elastic member 600 has a surface roughness (SRO) less than about 10 μm. The SRO is a physical property of a composite elastic member. The SRO shows a degree of deviation of the surfaces of the composite elastic member. For example, a composite elastic member 600 which has a relatively greater SRO value increases the possibility of causing a reddening mark on the user's skin when the user places the disposable article using said composite elastic member. This is due if a composite elastic member has a rough surface (ie, convex portions and concave portions on the first surface 501 (or the second surface 502), forces that are generated by the composite elastic member 600 and are directed towards the skin of the user concentrating on the convex portions It is believed that such a concentration of forces causes the problem of reddened marking A method for defining the SRO of the composite elastic member is described in the section "Test Methods". preferred, the composite elastic member 600 has an ORS less than about 8 μm, preferably less than about 5 μm A preferred composite elastic member 600 which has a relatively lower ORS is formed by applying a predetermined pressure at a predetermined temperature to a member elastic composite precursor for a predetermined period of time.Here, "elastic member "precursor compound" can be any of the composite elastic members 500 described above. The resulting elastic composite member 600 is referred to as "flattened composite elastic member" hereinafter. In a preferred embodiment, the predetermined temperature is less than the melting point of the fibrous material. In a preferred embodiment wherein the elastomeric flat material 520 includes soft segments and hard segments, the predetermined temperature is higher than the glass transition temperature of the hard segments.

Figure 5 shows a preferred example of the pressure applying device 800 for forming a flattened composite elastic member. Any of the composite elastic members 500 described above can be used as an elastic precursor composite member 810 to form the flattened composite elastic member 820. Referring to Figure 5, the pressure applying device 800 includes a first pressure plate 801 having a first surface 803, and a second plate 802 having a second surface 804. The second pressure plate 802 is fixed, while the first pressure plate 801 is capable of moving to apply a pressure P to the precursor composite elastic member 801 in cooperation with the second pressure plate 802. Preferably, the first and second surfaces 803 and 804 are substantially flat and are substantially parallel to each other. The composite elastic member 810 is manually supplied to the pressure applying device 800. A preferred pressure applying device 800 is available from Toyo Tester Industry Co., Ltd., Osaka, Japan, under the trade name "Heat Sealer". In the process of applying pressure, the first surface 803 of the elastic composite member 810 is heated to a temperature T1, while the second surface 804 is heated to a temperature T2. Preferably, the temperatures T1 and T2 are selected within a predetermined range such that any of the entanglement fibers 550 can not be melted at the pressure P.

This is preferred because the fusion of the entanglement fibers 550 tends to increase the SRE value of the resultant flattened composite elastic member 820. Additionally, avoiding such fusion of any of the entanglement fibers 550, it is possible to maintain the elongation capacity of the flattened composite elastic member resulting 820 within a preferred range.

In the preferred embodiments where the composite elastic members 500 described above (Code Numbers PC160A; PC160B; PC170B and PC170C) are used as the elastic precursor composite members 810, the temperature T1 is from about 80 ° C to 160 ° C, more preferably from about 90 ° C to about 1 10 ° C. The temperature T2 is preferably from about 40 ° C to about 65 ° C, more preferably from about 50 ° C to about 60 ° C. The pressure P is preferably from about 6 kg / cm2 to about 15 kg / cm2, more preferably from about 9 kg / cm2 to about 11 kg / cm2. The time period of application of the pressure P is preferably from about 1 second to about 20 seconds, more preferably from about 5 seconds to about 15 seconds. Preferably, the application of pressure P can be performed twice (or more times) to decrease the SRO value of the resulting composite elastic member 820. By applying the temperatures T1 and T2 to the pressure P, the elastic composite precursor member 810 (ie, the flat heromeric material 520 as well as the fibrous material 540) is flattened to decrease the value of the SRO purchased with that of the elastic composite precursor member 810 (e.g., the composite elastic member 500 shown in Figure 3). The resultant flattened composite elastic members 820 have the following values of SRO in the machine direction (MD) which are relatively greater than those in the cross machine direction (CD). (The table below also shows the SRO values of the elastic composite precursor members before the flattened formation for reference purposes).

Table II The composite elastic member of the present invention can be incorporated into a variety of products where it is desired to provide an elastic elongation ability in at least one structural direction either partially or totally. Examples of such products include disposable items, including sweat bands, bandages, wraps for the body, and disposable garments including disposable diapers and incontinence products. Next, the applications for disposable garments that stretch as the preferred embodiments of the present invention are described. One or more of the composite elastic members described above will preferably be used as, for example, the elastic members 70 and 700 shown in Figures 9, 10 and 1 1. Figure 6 shows a preferred embodiment of a disposable diaper that stretches from the present invention (ie, a unitary disposable diaper that stretches 120). Referring to Figure 6, the disposable diaper 120 has a front region 26; a back region 28 and a crotch region 30 between the front region 26 and the back region 28. A chassis 41 is provided in the front, back and crotch regions 26, 28 and 30. The chassis 41 includes a permeable topsheet 24. to the liquid, a backsheet 22 impermeable to the liquid associated with the topsheet 24, and an absorbent core 25 (not shown in Figure 6) disposed between the topsheet 24 and the backsheet 22. The chassis 41 has side edges 220 that they form the edge lines 222 in the front region 26. The stretch garment 120 further includes at least a pair of extendable ear panels 45 each extending laterally outwardly from corresponding sides of the chassis 41. Each of the panels ear 45 has an outermost edge 240 that forms an outermost edge line 242. At least one of the outermost edge lines 242 has a non-uniform lateral distance from the line longitudinal center 100 (not shown in Figure 6) in a non-contracting state of garment 120. In a preferred embodiment, ear panels 45 extend continuously from corresponding sides of chassis 41 in back region 28 toward the edges corresponding laterals 220 of the chassis 41 in the frontal region 26 as shown in Figure 6. Alternatively, the ear panels 45 can extend continuously from the corresponding sides of the chassis 41 in the frontal region 26 towards the corresponding lateral edges of the chassis 41 in the posterior region 28 (not shown in Figure 6). The stretched garment 120 has ear panels 45 attached to the chassis 41 to form two leg openings 34 and a waist opening 36. Preferably, the stretchable garment 120 further includes stitching 232 attaching each to the chassis 41 and the ear panels. 45 along the corresponding edge lines 222 and 242 to form two leg openings 34 and the waist opening 36. Figure 7 shows another preferred embodiment of a disposable stretchable garment of the present invention (ie, a diaper disposable unit that stretches 20).

Referring to Figure 7, the disposable garment 20 includes a pair of extendable front ear panels 46 each extending laterally outwardly from the corresponding sides of the chassis 41 in the front region 26, and a pair of extendable ear panels posteriorly. 48 each extending laterally outwardly from the corresponding sides of the chassis 41 at the rear region 28. Each of the ear panels 46 and 48 has an outermost edge 240 that forms the outermost edge line 242. At least one of the outermost edge lines 242 has a non-uniform lateral distance LD from the longitudinal centerline 100 (not shown in FIG.

Figure 7 but in Figure 8) in a non-contracting state of the garment 20. The stretched garment 20 further includes stitching 32 each attaching the front and rear ear panels 46 and 48 along the shore lines 242 corresponding to form two leg openings 34 and waist opening 36. In a preferred embodiment, at least one, more preferably both, of the pairs of ear panels 45, 46 and 48 are elastically extensible in at least the direction side. In one embodiment, the ear panels 45, 46 and 48 are also elastically extensible in the longitudinal direction. The elastically extensible ear panels 45, 46 and 48 provide a more comfortable and contoured fit by initially initially comfortably fitting the garment that stretches the wearer and holding this fit or notch throughout the time of use even after the wearer has loaded the garment that stretches with exudates since the ear panels 45, 46 and / or 48 allow the sides of the stretch garment to expand and contract. The ear panels 45, 46 and 48 can be formed by unitary elements of the garment stretching 20 or 120 (ie, these are not separately manipulated elements secured to the garment stretching 20 or 120, but instead are formed to from and are extensions of one or more of the various layers of the garment that stretches). In a preferred embodiment, each of the ear panels 45, 46 and 48 is a projected member of chassis 41 (shown more clearly in Figure 8). Preferably, the ear panels 45, 46 and 48 include at least one element. unit or a continuous sheet material (e.g., the non-woven outer cover 74 in Figure 9) that forms a part of the chassis 41 and extends continuously to the ear panels 45, 46 and 48. Alternately, the ear panels 45, 46 and 48 can be discrete members (not shown in the Figures) that do not have any unitary element that forms a part of the chassis 41, and can be formed by joining the discrete members to the corresponding sides of the chassis 41. In a preferred embodiment, the stretch garment 20 or 120 further includes seam panels 66 each extending laterally outwardly from each of the ear panels 45, 46 and 48, and tear-open tabs 31 extending each laterally. e outside of the sewing panel 66. In a preferred embodiment, each of the seaming panels 66 is an extension of the ear panels 45, 46 and 48, or at least one of the component elements used therein, or any other combination of the elements. More preferably, each of the tear-opening tabs 31 is also an extension of the corresponding seam panel 66 or at least one of its component elements used therein, or any other combination of its elements. In a preferred embodiment, the corresponding edge portions of the chassis 41 and / or the ear panels 45, 46 and 48 are sewn directly or indirectly (for example, through the seam panels 66), in an overlapping shape to form an overlapping seam structure. Alternatively, the front and rear ear panels 46 and 48 may be sewn in a splice seam manner (not shown in the Figures). The joining of the seams 32 can be accomplished by any suitable means known in the art appropriate for the specific materials employed in the chassis 41 and / or the ear panels 45, 46 and 48. Thus, sonic sealing can be appropriate techniques. , heat sealing, pressure bonding, adhesive or adherent bonding, sewing, autogenous bonding, and the like.GR.

Preferably, the seam panels 66 are joined by a predetermined pattern of ultrasonic or heat / pressure welds which withstand the forces and stresses generated on the garment 20 or 120 during use. A continuous belt 38 is formed by the ear panels 45, 46 and 48, and a portion of the chassis 41 around the waist opening 36 as shown in Figures 6 and 7. Preferably, the elastified waistbands 50 are provided in both the front region 26 as the back region 28. The continuous belt 38 acts to dynamically create adjustment forces in the notch garment 20 or 120 when placed on the wearer, to keep the garment stretching 20 or 120 in the garment. user even when loaded with the exudates of the body thereby maintaining the absorbent core 25 (not shown in Figure 7) in close proximity to the user, and to distribute the dynamically generated forces during use around the waist thereby providing support complementary to the absorbent core 25 without agglomerating or bulking the absorbent core 25. Figure 8 is a partially cut away plan view of the stretch garment 20 of Figure 7 in their unstressed state (except in the ear panels 46 and 48 which are left in their relaxed condition) with the topsheet 24 giving the observer, before the ear panels 46 and 48 are joined together by the seams 32 The stretched garment 20 has the front region 26, the back region 28 opposite the front region 26, the crotch region positioned between the front region 26 and the back region 28, and a periphery that is defined by the outer perimeter u. edges of the stretching garment 20 in which the side edges are designated 150 and 240, and the end edges or waist edges are designated 152. The topsheet 24 has a surface that gives the body of the garment stretching 20 the which is placed adjacent to the body of the user during use. The backsheet 22 has the outward facing surface of the stretchable garment 20 which is positioned away from the wearer's body. The stretched garment 20 includes the chassis 41 including the liquid permeable upper sheet 24, the liquid impermeable back sheet 22 associated with the upper sheet 24, and the absorbent core 25 positioned between the upper sheet 24 and the back sheet 22. garment 20 further includes the front and rear ear panels 46 and 48 extending laterally outwardly of the chassis 41, elasticized leg cuffs 52, and the elasticized waistbands 50. The upper sheet 24 and the backsheet 22 have length and width dimensions generally greater than those of the absorbent core 25. The topsheet 24 and the backsheet 22 extend beyond the edges of the absorbent core 25 to thereby form the side edges 150 and the waist edges 152 of the garment 20. The backsheet 22 liquid impervious preferably includes a plastic film impervious to liquid 68. The stretch garment 20 also has two centerlines, a longitudinal center line 100 and a transverse center line 110. Here, "longitudinal" refers to a line, axis, or direction within the plane of the stretching garment 20 that is generally aligned with (e.g., approximately parallel to) a vertical plane that divides a user standing in left and right halves when wearing the garment that stretches 20. Here, "transverse" and lateral "are interchangeable and refer to a line, axis or direction that is located within the plane of the stretch garment that is generally perpendicular to the longitudinal direction (which divides the user into front and rear body halves). The stretchable garment 20 and the component materials thereof also have a surface that faces the body which faces the wearer's skin during use and an outward facing surface which is the surface opposite the surface that it gives. to the body. Each of the ear panels 45, 46 and 48 have the outermost edge line 242. Here, "shore line" refers to the lines defining the contours of the ear panels 45, 46 and 48 or the chassis 41. Here, "more external" refers to the portions that are furthest from the longitudinal center line 100. At least one of the edge lines 242 has a non-uniform lateral distance LD from the longitudinal centerline 100 in the state without shrinking of the garment 20. Although the upper sheet 24, the backsheet 22, and the absorbent core 25 can be assembled in a variety of well-known configurations, illustrative chassis configurations are generally described in the United States patent.

United No. 3,860,003 entitled "Shrinkable side portions for disposable diaper" which was issued to Kenneth B. Buell on January 14, 1975; and in U.S. Patent No. 5,151,092 entitled "Absorbent Article Characteristic of Dynamic Elastic Waistband Having a Resilient Resilient Flexure Joint" which was issued to Kenneth B. Buell et al. on September 29, 1992. Figure 9 is a cross-sectional view of a preferred embodiment taken along the section line 4-4 of Figure 8. The stretched garment 20 includes the chassis 41 including the liquid-permeable upper sheet 24; backsheet 22 impermeable to liquid associated with the topsheet 24, and the absorbent core 25 disposed between the topsheet 24 and the backsheet 22. The stretchy garment 20 further includes the front ear panel 46 extending laterally outwardly of the chassis 41 and an internal barrier fold 54. Although Figure 9 illustrates only the structure of the front ear panel 46 and the chassis 41 in the front region 26, it is also preferably provided a similar structure in the back region 28. In a preferred embodiment, the front ear panel 46 is formed by a lamination of an extended portion 72 of the barrier flap 56, an elastic member 70 and the outer nonwoven cover 74. Any of the composite elastic members described above can be used as the elastic material 70. The absorbent core 25 can be any absorbent member that is generally compressible, capable of shaping, non-irritating to the user's skin, and capable of absorbing and retaining the fluids such as urine and other certain exudates from the body. The absorbent core 25 can be manufactured in a wide variety of sizes and shapes (eg, rectangular, hourglass, T-shaped, asymmetrical, etc.) and from a wide variety of liquid absorbent materials commonly used in stretch disposable garments and other absorbent articles such as crushed wood pulp which is generally referred to as air felt. Examples of other suitable absorbent materials include crushed cellulose wadding; meltblown polymers including coform; chemically hardened, modified or interlaced cellulosic fibers; tissue, including tissue wraps and tissue laminates; absorbent foams; absorbent sponges; superabsorbent polymers; gelling absorbent materials; or any equivalent material or combinations of materials. The configuration and construction of the absorbent core 25 may vary (e.g., the absorbent core 25 may have zones of varying gauge, a hydrophilic gradient, a superabsorbent gradient, or acquisition zones with lower average density and lower average basis weight, or may include one or more layers or structures).

In addition, the size and absorbent capacity of the absorbent core 25 can also be varied to suit users ranging from babies to adults. However, the total absorbent capacity of the absorbent core 25 must be compatible with the design load and intended use of the garment 20. A preferred embodiment of the garment 20 has an asymmetric absorbent core 25, in the form of a modified hourglass, having ears in the front and rear waist regions 26 and 28. Other exemplary absorbent structures for use as the absorbent core 25 that have achieved wide acceptance and commercial success are described in U.S. Patent No. 4,610,678 entitled "Absorbing structures. high density "issued to Weisman and others on September 9, 1986; U.S. Patent No. 4,673,402 entitled "Absorbent articles with cores in double layers" issued to Weisman et al. on June 16, 1987; U.S. Patent No. 4,888,231 entitled "Absorbent Core Having A Dust Cap" issued to Angstadt on December 19, 1989; and U.S. Patent No. 4,834,735 entitled "High density absorbent members having acquisition zones with lower density and lower basis weight" issued to Alemany et al. on May 30, 1989. The chassis 41 may further include a core of acquisition / distribution 84 of chemically hardened fibers placed on the absorbent core 25, thus forming a dual core system. In a preferred embodiment, the fibers are chemically hardened hydrophilic cellulosic fibers. Here, "chemically hardened fibers" means any of the fibers that have been hardened by chemical means to increase the stiffness of the fibers under both dry and aqueous conditions. These means include the addition of chemical curing agents which, for example, coat and / or impregnate the fibers. Such means also include hardening the fibers by altering the chemical structure of the fibers themselves, for example, by interlacing polymer chains. The fibers used in the acquisition / distribution core 84 can also be hardened by chemical reaction. For example, the crosslinking agents can be applied to the fibers which, after application, are chemically formed to form intrafiber lattice bonds. These lattice junctions can increase the stiffness of the fibers. While the use of intrafiber lattice bonds to chemically harden fibers is preferred, this does not mean excluding other types of reactions for chemical stiffness of the fibers. In more preferred hardened fibers, processing includes intrafiber crosslinking with crosslinking agents while the fibers are in a relatively dehydrated, defibrated (ie, individualized), twisted, crimped condition. Suitable hardening chemicals include monomeric crosslinking agents including, but not limited to C2-C8 dialdehydes and C2-C8 monoaldehydes having an acidic functionality that can be employed to form the crosslinking solution. These compounds are capable of reacting with at least two hydroxyl groups on a single cellulose chain or on cellulose chains located in a close proximity to a single fiber. Such crosslinking agents contemplated for use in preparing the hardened cellulosic fibers include, but are not limited to, glutaraldehyde, glyoxal, formaldehyde, and glyoxylic acid. Other suitable curing agents are polycarboxylates, such as citric acid. The hardening polycarboxylic agents and a process for making hardened fibers from these are described in U.S. Patent No. 5,190,563 entitled "Process for preparing individualized fibers, crosslinked with polycarboxylic acid" issued to Herron, on March 2, 1993. The effect of crosslinking under these conditions is to form fibers that are stiffened and which tend to retain their twisted, curled configuration during use within the absorbent articles herein. Said fibers, and the processes to elaborate it, are cited in the previously incorporated patents. The preferred dual-core systems are disclosed in the patent of the United States No. 5,234,423, entitled "Absorbing article with characteristic elastic waist and improved absorbency" issued to Alemany et al., On August 10, 1993; and in U.S. Patent No. 5,147,345 entitled "High Efficiency Absorbent Handling Articles for Incontinence Management" issued to Young, LaVon, and Taylor on September 15, 1993. In a preferred embodiment, the acquisition / distribution core is provided in a preferred embodiment. includes chemically treated hardened cellulosic fiber material, available from Weyerhaeuser Co. (EUA) under the trade designation "CMC". Preferably, the acquisition / distribution core 84 has a basis weight of from about 40 g / m2 to about 400 g / m2, more preferably from about 75 g / m2 to about 300 g / m2. More preferably, the chassis 22 further includes an acquisition / distribution layer 82 between the top sheet 24 and the acquisition / distribution core 84 as shown in Figure 9. The acquisition / distribution layer 82 is provided to assist reducing the tendency of the surface moisture of the top sheet 24. The acquisition / distribution layer 82 preferably includes carded, high-flux bonded non-woven materials such as, for example, available as code No. FT-6860 by from Polymer Group, Inc., North America (Landisiville, New Jersey, USA), which is made of 6 dtex polyethylene terephthalate fibers and has a basis weight of about 43 g / m2. A preferred example for the acquisition / distribution layer 82 and the acquisition / distribution core 84 is disclosed in European patent EP 0797968A1 (Kurt et al.) Published on 1. October 1997. The topsheet 24 is preferably docile, gentle in feel, and non-irritating to the user's skin. In addition, the topsheet 24 is permeable to liquid allowing liquids (eg, urine) to easily penetrate through its thickness. A suitable top sheet 24 can be manufactured from a wide range of materials such as woven and nonwoven materials; polymeric materials such as thermoplastic films formed with openings, plastic films with openings, and hydroformed thermoplastic films; porous foams; cross-linked foams; crosslinked thermoplastic films; and thermoplastic canvases. Suitable woven and nonwoven materials may be included from natural fibers (e.g., wool or cotton fibers), synthetic fibers (e.g., synthetic fibers such as polyester, polypropylene, or polyethylene fibers) or from a combination of fibers natural and synthetic The topsheet 24 is preferably made of a hydrophobic material to isolate the wearer's skin from the liquids that have passed through the topsheet 24 and which are contained within the absorbent core 25 (ie, avoid rewetting). If the topsheet 24 is made of a hydrophobic material, at least the top surface of the topsheet 24 is treated to be hydrophilic so that liquids will transfer more rapidly through the topsheet. This decreases the likelihood that the body exudates will flow out of the topsheet 24 instead of being drawn through the top sheet 24 and absorbed by the absorbent core 25. The topsheet 24 can be made hydrophilic by treating it with an agent surfactant. Suitable methods for treating the topsheet 24 with a surfactant include spraying the matepal from the topsheet 24 with the surfactant and immersing the material in the surfactant. A more detailed discussion of such treatment and hydrophilic ability is contained in U.S. Patent No. 4,988,344 entitled "Absorbent articles with multi-layer absorbent layers" issued to Reising, et al. On January 29, 1991 and in the U.S. Patent No. 4,988, 345 entitled "Absorbent articles with fast acquisition absorbent cores" issued on January 29, 1991. In a preferred embodiment, the topsheet 24 is a nonwoven web that can provide the reduced tendency for surface moisture; and consequently it facilitates keeping the urine absorbed by the absorbent core away from the wearer's skin, after wetting. One of the preferred materials of the topsheet is a thermally bonded carded web which is available as the P-8 code number from Fiberweb North America, Inc. (Simpsonville, South Carolina, USA). Another preferred material for the topsheet is available as code number S-2355 from Havix Co., Japan. This material is a composite material of two layers, and made of two types of synthetic two-component fibers treated with surfactant using carding and direct air technologies. Still another preferred material of the topsheet is a thermobonded carded web which is available as the code number Profleece Style 040018007 from Amoco Fabrics, Inc. (Gronau, Germany). Another preferred top sheet 24 includes a film formed with openings. Films formed with apertures for the topsheet 24 are preferred because they are permeable to the exudates of the stub and still non-absorbent and have a reduced tendency to allow liquids to pass back through and re-wet the user's skin. . Therefore, the surface of the formed film which is in contact with the body remains dry, thus reducing the staining of the body and creating a more comfortable feeling for the user. Suitable formed films are described in U.S. Patent No. 3,929,135 entitled "Absorption structures having tapered capillaries" issued to Thompson on December 30, 1975; U.S. Patent No. 4,324,246 entitled "Disposable absorbent article having a stain resistant top sheet" issued to Mullane, et al. on April 13, 1982; U.S. Patent No. 4,342,314 entitled "Resilient plastic weft exhibiting fiber-like properties" issued to Radel et al. on August 3, 1982; U.S. Patent No. 4,463,045 entitled "Macroscopically expanded three-dimensional plastic screen exhibiting a non-glossy visible surface and a fabric-like fingerprint" issued to Ahr et al. on July 31, 1984; and U.S. Patent No. 5,006,394"Multilayer polymeric film" issued to Baird on April 9, 1991. In a preferred embodiment, the backsheet 22 includes a liquid impervious film 68 as shown in, for example, Figure 9. Preferably, the liquid impervious film 68 extends longitudinally in the front, back and crotch regions 26, 28 and 30. More preferably, the liquid impermeable film 68 does not extend laterally toward at least one of the ear panels 46 or 48. The liquid imeable film 68 has a surface that faces the body 79 and an exterior facing surface 77. The liquid imeable film 68 is imeable to liquids (eg, urine) and is preferably manufactured from a plastic film. thin. However, preferably the plastic film allows the vapors of the garment 20 to escape. In a preferred embodiment, a microporous polyethylene film is used for the liquid imeable film 68. A suitable polyethylene microporous film is manufactured by Mitsui Toatsu Chemicals, Inc., Nagoya, Japan and commercialized as PG-P. In a preferred embodiment, a disposable tape (not shown in the Figures) is additionally attached to the outer surface of the backsheet 22 to provide disposal for convenient disposal after soiling. A suitable material for the liquid imeable film 68 is a thermoplastic film having a thickness of about 0.012 mm to about 0.051 mm, preferably including polyethylene or polypropylene. Preferably, the liquid ivious film has a basis weight of about 5 g / m2 to about 45 g / m2. However, it must be distinguished that other flexible liquid ivious materials can be used. Here, "flexible" refers to materials that are docile and that will easily conform to the figure and general outline of the user's body. The non-woven outer cover 74 is attached to the side facing the outside of the waterproof film 68 to form a laminate (i.e., the back sheet 22). The non-woven outer cover 74 is positioned in the outermost portion of the garment 20 and covers at least a portion of the outermost portion of the garment 20. In a preferred embodiment, the non-woven outer cover 74 covers almost the entire area of the garment. the outermost portion of the garment 20. The nonwoven outer cover 74 may be attached to the liquid imeable film 68 by any suitable joining means known in the art. For example, the nonwoven outer cover 74 may be secured to the liquid ivious film 68 by a continuous uniform adhesive layer, a patterned adhesive layer, or an array of separate lines, coils, or spots of adhesive. Suitable adhesives include a thermal fusion adhesive obtainable by Nitta Findley Co., Ltd., Osaka, Japan as H-2128, and a thermal fusion adhesive obtainable by H.B. Fuller Japan Co., Ltd., Japan as JM-6064. In a preferred embodiment, the nonwoven outer cover 74 is a carded nonwoven web, for example, obtainable from Havix Co., LTD., Gifu, Japan as E-2341. The non-woven outer cover 74 is made of two-component fibers of a polyethylene (PE) and a polypropylene (PP). The PE / PP ratio is approximately 50/50. The PE / PP two-component fiber has the dimension of 2d x 51 mm. Another preferred carded nonwoven web is obtainable from Chisso Corp., Moriyama, Japan. The non-woven outer cover 74 is also made of two-component fibers of a polyethylene (PE) and a polypropylene (PP). The PE / PP ratio is approximately 50/50. In another preferred embodiment, the non-woven web is a spin-linked web, for example, obtainable from Mitsui Petrochemical Industries, Ltd., Tokyo, Japan. The nonwoven web is made of two-component fibers of a polyethylene (PE) and a polypropylene (PP). The PE / PP ratio is approximately 80/20. The PE / PP two-component fiber has a thickness of approximately 2.3d. Another nonwoven web linked by spinning is obtainable from Fiberweb France S.A., under the code number 13561 DAPP. The topsheet 22 is preferably positioned adjacent the surface that faces the outside of the absorbent core 25 and is preferably attached to it by any joining means known in the art. For example, the backsheet 22 can be secured to the absorbent core 25 by a continuous uniform adhesive layer, a patterned adhesive layer, or an array of separate lines, spirals or spots of adhesive. The adhesives that have been found to be satisfactory are manufactured by H.B. Fuller Company of St. Paul, Minnesota, USA and marketed as HL-1358. An example of a suitable attachment means including an open pattern web of adhesive filaments is disclosed in U.S. Patent No. 4,573,986 entitled "Disposable Garment of Waste Containment" which was issued to Minetola et al. March 1986. Another suitable joining means including several lines of adhesive filaments twisted in a spiral pattern is illustrated by the apparatus and methods shown in United States Patent No. 3,911,173 issued to Sprague Jr. on March 7, 1986. October 1975; U.S. Patent No. 4,785,996 issued to Ziecker, and others on November 22, 1978; and United States patent No. 4,842,666 issued to Werenicz on June 27, 1989. Alternatively, the joining means may include heat bonds, pressure joints, ultrasonic joints, mechanical dynamic joints, or any other suitable joining means or combinations of these means of binding as are known in the art. In an alternative embodiment, the absorbent core 25 is not bonded to the backsheet 22 and / or to the topsheet 24 in order to provide greater extension capacity in the front region 26 and in the back region 28. The garment that stretches 20 preferably further includes elasticized leg folds 52 to provide improved containment of liquids and other exudates from the body. The elasticized leg folds 52 may include several different modalities to reduce leakage of body exudates in the leg regions. (Leg bends can be and sometimes are also referred to as leg bands, side flaps, barrier folds, elastic folds or packing folds.) U.S. Patent No. 3,860,003 entitled "Shrinkable side portions for disposable diaper. "issued to Buell on January 14, 1975, describes a disposable diaper that provides a collapsible opening for the leg having a side flap and one more elastic members to provide an elasticized leg fold. U.S. Patent No. 4,909,803 entitled "Disposable Absorbent Article Having Elasticized Fins" issued to Aziz et al. On March 20, 1990, discloses a disposable diaper having "upright" elasticated fins (barrier folds) to improve the containment of the regions in the leg.

U.S. Patent No. 4,695,278 entitled "Absorbent Article Having Double Folds" issued to Lawson on September 22, 1987; and in U.S. Patent No. 4,795,454 entitled "Absorbent Article Having Double Leak-Resistant Folds" issued to Dragoo on January 3, 1989, discloses disposable diapers having double folds that include a fold of packing and a fold of barrier. U.S. Patent No. 4,704,115 entitled "Disposable Garment for Containment of Waste" issued to Buell on November 3, 1987, discloses a disposable diaper or garment for incontinence that has channels for guarding leaks on the shore laterals configured to contain the free liquids inside the garment. Although each elasticized leg fold 52 can be configured to be similar to any of the legbands, side flaps, barrier folds, or elastic folds described above, it is preferred that the elasticized leg fold 52 include an elastic fold of gasket 62 with one or more elastic cords 64 as shown in Figure 8, which is described in the above-referenced U.S. Patent Nos. 4,695,278 and 4,795,454. It is also preferred that each leg elastified fold 52 further includes internal barrier folds 54 each including a barrier flap 56 and a separation means 58 which is described in the aforementioned US Patent No. 4,795,454. The stretchable garment 20 further includes an elasticized waistband 50 which provides improved fit and containment. The elasticized waistband 50 is that portion or area of stretching garment 20 that is intended to expand and contract elastically to dynamically adjust to the wearer's waist. The waistband 50 includes an elastic member 700. Any of the composite elastic members described above can be used as the elastic member 700. The waistband 50 is disposed along at least one, preferably both, of the end edges. 152 of the disposable garment 20. The elasticized waistband 50 preferably extends longitudinally inwardly of the end edge 152 of the garment stretching 20 toward the waist edge 154 of the absorbent core 25. Preferably, the stretching garment 20 has two elasticated waistbands 50, one placed in the back region 28 and one placed in the front region 26, although other modalities of the diaper can be constructed that stretch with an individual elasticized waistband. The elastic waistband 50 can be constructed in a number of different configurations including those described in U.S. Patent No. 4,515,595 entitled "Disposable diapers with elastically shrinkable waistbands" issued to Kievit et al. On May 7, 1985 and the United States No. 5,151, 092 issued to Buell referred to above. Figure 10 is a cross-sectional view of a preferred embodiment taken along the section line 5-5 of Figure 8. As shown in Figure 10, both the backsheet 22 and the top sheet 24 extend further beyond the waist edge 154 of the absorbent core 25 to define a waist flap 156. Preferably, the juxtaposed areas of the backsheet 22 and top sheet 24 are joined together by an adhesive (not shown in the Figures). In a preferred embodiment, the waistband 50 is attached to the waist flap 156. Preferably, the waistband 50 is disposed on and is attached to the top sheet 24 as shown in Figure 10. Alternatively, the waistband 50 may be arranged in and attached between the backsheet 22 and the topsheet 24 as shown in Figure 11. The waistband 50 may be attached to the topsheet 24 (and the backsheet 22) by an adhesive element (not shown in the Figures). ) such as those well known in the art. For example, the waistband 50 can be secured to the waist flap 156 by a continuous uniform adhesive layer, a patterned adhesive layer, or an array of separate lines or spots of adhesive. A preferred adhesive to be used is available from Ato Findley Inc., Wl, USA, under the designation H2085. In a preferred embodiment, the waistband 50 is secured to the waist flap 156 in an elastically collapsible condition so that in a normally unrestricted configuration the waistband 50 will effectively contract or shirm the waist flap 156. The waistband 50 can be secured to the waist flap 156 in an elastically contractible condition in at least two ways. For example, the waistband 50 can be stretched and secured to the waist flap 156 while the waist flap 156 is in an uncontracted condition. Alternatively, the waist flap 156 may be contracted, for example folded, and the waistband 50 secured to the contracted waist flap 156 while the waistband 50 is in its relaxed or unstretched condition. Still alternately, the waistband 50 is attached, in its relaxed or unstretched condition, to the waist flap 156 which is in an uncontracted condition, thus forming a composite laminate with the materials of the backsheet 22 and the sheet upper 24. At least one portion, preferably the total portion of the composite laminate is then subjected to sufficient mechanical stretching to permanently elongate the non-elastic components that are the backsheet 22 and the top sheet 24. Then the composite laminate is allowed to return to its substantially unstressed condition. In this way, the composite laminate is formed into a stretch laminate with "zero tension" which functional as elasticized waistband 50. Here, stretch laminate with "zero tension" refers to a laminate that includes at least two layers of material which are secured to one another along at least a portion of their coextensive surfaces while in a substantially unstressed condition ("zero voltage"); one of the layers including a material that is stretchable and elastomeric (i.e., it will substantially return to its unstressed dimensions after an applied tension force has been released) and a second layer that is elongate (but not necessarily elastomeric) in shape such that when stretching the second layer will be, at least to a degree, permanently elongated in such a way that when releasing the applied tension forces, it will not return completely to its original configuration without deforming. The resulting stretch laminate is thus made elastically extensible, at least up to the initial stretch point, in the direction of initial stretch. Particularly preferred apparatuses and methods used to form the stretch laminates use corrugated gear rollers to mechanically stretch the components. Particularly preferred apparatuses and methods are described in U.S. Patent No. 5,167,897 issued to Weber et al. December 1992; U.S. Patent No. 5,156,793 issued to Buell et al. on October 20, 1990; and in United States Patent No. 5,143,679 issued to Weber and others on 1 o. September 1992. In a preferred embodiment, the waistband 50 extends essentially across the total lateral width of the absorbent core 25. Here, "side width" refers to the dimension between the side edges of the components of the disposable garments. Here, "essentially through" is used in this context to indicate that the waistband 50 does not need to extend absolutely across the full width of the absorbent core 25 while extending far enough across the width thereof to provide the elasticised waistband. . Preferably, the waistband 50 extends through only a portion of the lateral width of the absorbent core 25, more preferably at least between the portions in the ear panels 46 and 48 (as shown in Figure 8). In a preferred embodiment, the waistband 50 extends through the total lateral width of the garment 20 (not shown in the Figures). The limit at which the waistband 50 extends inward from the end edge 152 of the garment 20, and thus the longitudinal space of the resulting waistband, may vary according to the particular construction of the garment 20. The clearance or space The length of the waistband 50 is at least about 5 mm, preferably from about 6 mm to about 60 mm, more preferably from about 15 mm to about 30 mm. At least one of the ear panels 45, 46 and 48 includes the elastic member 70. Any of the composite elastic members described above can be used as the elastic member 70. For example, each of the front ear panels 46 shown in Figure 9 they include an elastic member 70, which preferably extends laterally outwardly of the chassis 41 to provide good fit by generating optimum (or sustained) retention force on the waist and the side areas of the wearer. Preferably, the elastic member 70 is extensible in at least one direction, preferably in the lateral direction to generate a holding force (or sustained) that is optimal to prevent the garment that stretches from falling., loosen or slide down your position on the torso without causing red marking on the user's skin. In a preferred embodiment, each of the ear panels 45, 46 and 48 includes the elastic member 70. The elastic member 70 is operatively bonded to at least one of the nonwoven webs 72 and 74 in the ear panels. 45, 46 and 48 to allow the elastic member to be elastically extensible in at least the lateral direction. In a preferred embodiment, the elastic member 70 is operatively bonded to the nonwoven webs 72 and 74 by securing them to at least one, preferably both, of the non-woven webs 72 and 74 while they are in a substantially unstressed condition ( zero voltage). The elastic member 70 can be operatively bonded to the non-woven webs 72 and 74, using either an intermittent joining configuration or a substantially continuous bonding configuration. Here, laminated weft "intermittently" attached means a laminated web wherein the webs are initially joined to each other at discrete discrete points or a laminated web wherein the webs are substantially loose from one another in discrete discrete areas. Conversely, a "substantially continuously bonded" laminate web means a laminated web wherein the webs are initially substantially continuously bonded to each other in all interface areas. It is preferred that the stretch laminate be bonded primarily or a significant portion of the stretch laminate such that the inelastic webs (ie, the non-woven webs 72 and 74) elongate or stretch without causing the break, and that the webs The stretch laminates are preferably bonded in a configuration that maintains all layers of the stretch laminate in relatively close adhesion to one another after the incremental mechanical stretching operation. Consequently, the elastic panel members and the other layers of the stretch laminate are preferably substantially continuously bonded using an adhesive. In a particularly preferred embodiment, the selected adhesive is applied with a control coating sprinkling pattern to a weight of approximately 7.0 grams / square meter. The width of the adhesive pattern is approximately 6.0 cm. The adhesive is preferably an adhesive such as is available from Nitta Findley Co., Ltd., Osaka, Japan, under the designation H2085F. Alternatively, the elastic panel member and any of the other components of the stretch laminates can be intermittently or continuously joined to each other using heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or any other method as is known in the art. After the elastic member 70 is operatively joined to at least one of the non-woven webs 72 and 74, at least a portion of the resulting composite stretch laminate is then subjected to sufficient mechanical stretching to permanently elongate the components. non-elastic which are, for example, the non-woven webs 72 and 74. The composite stretch laminate is then allowed to return to its substantially unstressed condition. At least one pair, preferably both of the ear panels 45, 46 and 48 are thus formed in the "no tension" stretch laminates. (Alternatively, the elastic member 70 can be operatively attached in a tensioned condition and then subjected to mechanical stretching, although this is not as preferred as a stretch laminate with "zero tension".) The elastic member 70 is attached preferably a, more preferably is directly secured to the respective edges 78 of the liquid impermeable film (ie, the liquid impermeable film 68) through an adhesive 76 as shown in Figure 9. In a preferred embodiment, while that the liquid impermeable film 68 extends longitudinally in the front, back and crotch regions 26, 28 and 30, it does not extend laterally to at least one, preferably to each of the extendable ear panels 45, 46 and 48. In a more preferred embodiment, the elastic member 70 is attached to the respective edges 78 of the liquid impervious film 68 on the exterior facing surface 77 as shown in Figure 9. In an alternative embodiment, the elastic member 70 may be attached to the respective edges 78 of the liquid impermeable film 68 on the exterior facing surface 79 (not shown in the Figures). Preferably, the adhesive 76 is applied in a spiral bonding pattern. In a preferred embodiment, the adhesive 76 is a flexible adhesive with an amorphous and crystallizing component. Such a preferred adhesive is obtainable from Nitta Findley Co., Ltd., Osaka, Japan under the designation H2085F. Alternatively, the elastic member 70 may be attached to the respective edges 78 of the liquid impermeable film 68 by another joining means known in the art which includes thermal joints, pressure joints, ultrasonic joints, mechanical dynamic joints, or combinations of these joining means.

Test Methods 1. Resistance to tension. The following method is used to measure the tensile strength of the composite elastic members and the elastomeric flat materials. A voltage tester is prepared. The tension tester has an upper jaw and a lower jaw which is located below the upper jaw. The upper jaw is able to move and is connected to a means of measuring extension force. The lower jaw is fixed in the tester. A test sample (i.e., an elastomeric flat material or a composite elastic member to be measured) which is approximately 2.5 cm wide and approximately 10.2 cm in length is prepared and clamped with the upper jaw and the lower jaw of Thus, the effective length of the sample (L) (ie, the initial distance between the upper and lower jaws before the application of the extension force) is approximately 5.1 cm. Preferably, the test sample is aligned, by fastening, with the direction that is very elastically extensible between all the two dimensional directions within the test sample. (This direction is referred to as "primary extendable direction" below.) An extension force is continuously applied to the test sample through the upper jaw at a crosshead speed of approximately 50 cm per minute, up to elongation of 300% of the test sample. The applied force of extension is registered by a registrar (for example, a computer system). This measurement is conducted for an elastomeric flat material and a composite elastic member. Preferably, this measurement is conducted repeatedly for at least 8 test samples and the average value of the tensile strength at 100% elongation is obtained from the recorded data. A suitable voltage tester for use is available from Instron Corporation (100 Royall Street, Canton, MA02021, USA) as an Instron 5564 code number. 2. Surface roughness To measure the surface roughness of the sample, a piano string is prepared and folded as shown in Figures 12 and 13. 5.0 gf (tolerance, ± 0.5 gf) of the contact force is applied by means of a spring. which the spring constant is ± 1 gf / mm. The natural frequency of the system must not be greater than 30 Hz when the contactor is out of contact. In the measurement of roughness, the sample is moved between a 2 cm interval by a constant speed of 0.1 cm / sec on a smooth steel plate placed horizontally where the tension of the sample is maintained 5.0 gf / cm (force per unit of length) and the contactor is held in its position. The direction of movement is an extendable direction of the sample. The dimension of the plate is shown in Figure 14. As a result, the change in thickness T (ie, the deviation of the surface) is obtained and recorded as shown, for example, in Figure 15. This measurement is driven for both surfaces opposite one another to the sample.

Consequently, the surface roughness value (SRO) is obtained from the following expression: 1 x SRO = - í | T - T '| dx X 0 where, x: displacement of the contactor on the surface of the sample, X: 2 cm is taken in this measurement; T: thickness of the sample in position x; and T ': average value of T An adequate equipment for this test is available from Kato Tech Co., Ltd., Kyoto, Japan, under the trade name "Surface Tester (KES-FB4)". It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes will be suggested by a person skilled in the art without departing from the scope of the present invention.

Claims (10)

1. An elastic member elastically extensible composite in at least one direction, comprising: an elastomeric flat material having a plurality of openings formed therein; and a fibrous material that includes entanglement fibers, the entangling fibers being hydroentangled with the elastomeric flat material through the openings; wherein the fibrous material has a tensile strength (SRE) less than about 100% at 100% elongation in the extensible direction.

The composite elastic member according to claim 1, wherein the composite elastic member has a tension or strain at 100% elongation of about 20 gf / cm to about 200 gf / cm.

The composite elastic member according to claim 1, wherein the elastomeric flat material has a basis weight of about 30 g / m2 to about 250 g / m2, and the fibrous material has a basis weight of about 5 g / m2 up to approximately 100 g / m2.

4. The composite elastic member according to claim 1, wherein the composite elastic member has a surface roughness (SR) less than about 10 μm.

The composite elastic member according to claim 1, wherein the entangling fibers are hydroentangled to each other uniformly within the adjacent openings of the elastomeric flat material.

The composite elastic member according to claim 1, wherein the entangling fibers are two component fibers having a side-to-side cross section or an eccentric cross section.

7. The composite elastic member according to claim 1, wherein the elastomeric flat material is an elastomeric canvas that includes a plurality of first cords and a plurality of second cords which intersect the first cords thereby forming the plurality of openings. A disposable article comprising the composite elastic member of claim 1. 9. The disposable article according to claim 8, wherein the disposable article is a disposable garment that includes at least a pair of extendable ear panels, and wherein at least one of the ear panels includes the composite elastic member of claim 1. The disposable garment according to claim 8, wherein the disposable article is a disposable garment that includes a waistband, and in wherein the waistband includes the elastic composite member of claim 1.