Stretchable nonwoven fabric laminate

Abstract

Stretch nonwoven laminates containing high recovery polyurethane elastic fibers, articles of manufacture comprising these stretch nonwoven laminates, and methods of making the stretch laminates and articles of manufacture are provided.

Description

[Technical Field]

[0001] The present disclosure relates to stretch nonwoven laminates comprising high recovery polyurethane elastic fibers, articles of manufacture comprising these stretch nonwoven laminates, and methods of making the stretch laminates and articles of manufacture. [Background technology]

[0002] For example, the use of elastomeric fibers, filaments, and / or films in leg bands and other components of disposable diapers has been known for many years. In a typical process for manufacturing these components, spandex fibers or filaments or natural or synthetic rubber film strips are stretched to a specific draft and bonded to one or two layers of a nonwoven substrate, for example, using a hot melt adhesive. This provides good stretch and recovery to the diaper component, e.g., the nonwoven substrate, which is elasticized by incorporating elastomeric fibers, filaments, and / or films into or on the component.

[0003] The adhesives used in this process often must be heated to high temperatures to form a good bond between the elastomeric fibers, filaments, or films and the material of the diaper component being elasticized, such as a nonwoven fabric or substrate. At these high temperatures, the break tenacity of the elastomeric fibers, filaments, or films is significantly lower than its break strength at room temperature (up to 75°F). If the break tenacity of the elastomeric fibers, filaments, or films at the high temperatures experienced at the point of contact with the hot melt adhesive is lower than the initial load force of the fibers, filaments, or films at room temperature and the draft used in the elasticization process, then the fibers, filaments, or films will break. Therefore, it is commonly known that breakage of elastomeric fibers, filaments, or films occurs during the process of preparing stretchable materials for hygiene product components if the elastomeric fibers, filaments, or films are overstretched or if the adhesive is heated to an excessively high temperature when in contact with the elastomer.

[0004] Typical process conditions for elasticizing materials for diaper components with spandex and hot melt adhesive involve the use of spandex fibers at a draft of 3.0 to 4.0 (200% to 300% elongation) and a standard elasticizing hot melt adhesive temperature of about 260°F to 325°F (127°C to 177°C) when the adhesive is applied by a spiral spray or strand coating process. If the spandex draft increases beyond 4.0 when the thermal adhesive is applied, the incidence of spandex breakage at the adhesive application point rapidly increases to unacceptable levels. Reducing the adhesive temperature below about 260°F (127°C) to reduce the heat load on the spandex fibers reduces the bond integrity between the spandex and the diaper component, e.g., nonwoven, to unacceptable levels.

[0005] Breaking of elastomeric fibers, filaments, or films in the manufacture of stretch structures used in disposable hygiene product components is highly undesirable because when the elastomer breaks, the disposable product production line must be stopped, the elasticized fibers, filaments, or films re-tensioned, and the equipment restarted, causing significant downtime on, for example, diaper production lines and resulting in a large number of discarded diapers.

[0006] U.S. Pat. No. 9,084,836 discloses a disposable hygiene product, such as a garment or a disposable diaper, comprising at least one relatively inelastic substrate, a polyurethane material selected from the group consisting of films and one or more filaments, comprising, as a basis for the soft segment of the polyurethane material, a glycol having a poly(tetramethylene-co-alkylene ether) structure, which includes structural units derived from copolymerizing tetrahydrofuran and a C2 or C3 alkylene oxide, wherein the portion of the units derived from the C2 or C3 alkylene oxide comprises at least 15 mol % of the poly(tetramethylene-co-alkylene ether) glycol; and a hot melt adhesive having a temperature of about 260°F to about 350°F. Summary of the Invention [Problem to be solved by the invention]

[0007] Despite the availability of components for disposable hygiene products that have been elasticized by the addition of adhesive or non-adhesive encapsulation of spandex, it would be advantageous to identify additional, stronger elastic materials for use in these products that are less susceptible to breakage. Specific benefits of such materials include thermal stability, reduced consumption of elastic material, increased efficiency of equipment operation (i.e., run time per package), and improved sustainability with respect to emissions and transportation costs. [Means for solving the problem]

[0008] overview One aspect of the present invention relates to a stretchable nonwoven laminate comprising high-resilience polyurethane elastic fibers and a nonwoven laminate. In one non-limiting embodiment, the high-resilience polyurethane elastic fibers are comprised of a polyol, an organic diisocyanate compound, and a diamine compound bonded to the nonwoven laminate. In one non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1800. In another non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600.

[0009] Another aspect of the present invention relates to an article of manufacture comprising, at least a portion of, a stretchable nonwoven laminate having high resilience polyurethane elastic fibers within or juxtaposed with the nonwoven laminate. In one non-limiting embodiment, the high resilience polyurethane elastic fibers are comprised of a polyol, an organic diisocyanate compound, and a diamine compound. In one non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1800. In another non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600.

[0010] Another aspect of the present invention relates to a method for producing a stretchable nonwoven laminate comprising high-resilience polyurethane elastic fibers within or juxtaposed with a nonwoven laminate. In one non-limiting embodiment, the high-resilience polyurethane elastic fibers are comprised of a polyol, an organic diisocyanate compound, and a diamine compound. In one non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1800. In another non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows a comparison of the mechanical properties of the yarns used in the present invention with a commercial example, LYCRA HyFit® fiber. [Figure 2]The mechanical properties of the 4-edge laminate at 3.8X draft from 0 to 150% on the third cycle are shown compared to a commercial comparative example. [Figure 3] 1 shows a comparison of the shrink force of pre-stretched laminates with a commercial example. [Figure 4] A comparison of the mechanical properties of the obtained yarns of Examples 18 to 25 is shown below. DETAILED DESCRIPTION OF THE INVENTION

[0012] Detailed Description The present disclosure provides stretchable nonwoven laminates, articles of manufacture that at least in part comprise stretchable laminates, and methods of making these stretchable nonwoven laminates and articles of manufacture.

[0013] In the present disclosure, the nonwoven laminate is elasticized by high recovery polyurethane elastic fibers that are contained within or juxtaposed with the nonwoven laminate.

[0014] "High recovery" polyurethane elastic fiber means a polyurethane elastic fiber having a normalized recovery per decitex at 200% of the fifth unload cycle, which is equal to or greater than 0.023 centiNewtons (cN) per decitex (dtex). High recovery polyurethane elastic fiber can be used to allow for an overall reduction in decitex compared to existing spandex fibers for nonwoven laminate applications. In one non-limiting embodiment, the decitex range is about 30-1500. In one non-limiting embodiment, the decitex range is about 33-1100.

[0015] In one non-limiting embodiment, high resilience polyurethane elastic fibers are adhered to a nonwoven fabric laminate and comprised of a polyol, an organic diisocyanate compound, and a diamine compound.

[0016] Polyols having two or more different repeating units can be used by blending or copolymerization. From the standpoint of strength and recovery, polyols blended with poly(tetramethylene ether) glycol (PTMEG) and poly(tetramethylene-co-2-methyltetramethylene ether) glycol (3MCPG) are preferred. Other polyols may be blended or copolymerized in any manner as long as the properties of PTMEG, 3MCPG, or a polyol blended with these two types are maintained. Commercially available examples of suitable polyols include Terathane® 1000 and Terathane® 650 (LYCRA, Wilmington, Delaware).

[0017] Examples of polyether polyols that can be used include glycols containing less than 12 carbon atoms and two or more hydroxyl groups per molecule, such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol, derived from ring-opening polymerization and / or copolymerization of ethylene oxide, propylene oxide, trimethylene oxide, tetrahydrofuran, and 3-methyltetrahydrofuran, or from condensation polymerization of polyhydric alcohols, such as diols or diol mixtures. Linear difunctional polyether polyols are preferred. The number-average molecular weight of the polyol should be about 450 to 1,800. In one non-limiting embodiment, the number-average molecular weight of the polyol is about 450 to 1,600. In one non-limiting embodiment, poly(tetramethylene ether) glycol is used having a number average molecular weight of about 650 to about 1400. The desired number average molecular weight can be achieved with a blend or mixture of two or more glycols that may be outside the desired molecular weight range.

[0018] In one non-limiting embodiment, the polyol is a polyether-based polyol. In one non-limiting embodiment, a low molecular weight polyol is blended with a high molecular weight polyol. In one non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1800. In one non-limiting embodiment, the polyol has a minimum number average molecular weight of 450 and a maximum number average molecular weight of 1600.

[0019] The diisocyanate used in the high-resilience polyurethane elastic fiber can be aromatic, alicyclic, or aliphatic. Examples of aromatic diisocyanate compounds include diphenylmethane diisocyanate (hereinafter abbreviated as MDI), tolylene diisocyanate, 1,4-diisocyanatobenzene, xylylene diisocyanate, and 2,6-naphthalene diisocyanate. Examples of alicyclic and aliphatic diisocyanates include methylenebis(cyclohexyl isocyanate) (hereinafter abbreviated as H12MDI), isophorone diisocyanate, methylcyclohexane 2,4-diisocyanate, methylcyclohexane 2,6-diisocyanate, cyclohexane 1,4-diisocyanate, hexahydroxylylene diisocyanate, hexahydrotolylene diisocyanate, and octahydro-1,5-naphthalene diisocyanate.

[0020] These diisocyanates can be used alone or in combination of two or more.

[0021] Among these diisocyanate compounds, aromatic diisocyanate compounds are preferred, and MDI is more preferred, due to their excellent strength and heat resistance for elastic fibers. One or more other types of aromatic diisocyanate compounds may be blended with MDI. The MDI may be a blend of 2,4'- and 4,4'-MDI isomers. Suitable MDI compositions include at least 90%, preferably more, of the 4,4'-MDI isomer, such as Dow Chemical's Isonate 125MDR®, Bayer's Desmodur® 44M, BASF's Lupranate® M, and Wanhua's Wannate® 1102IN.

[0022] In one non-limiting embodiment, the reactive equivalent ratio (molar ratio) of the organic diisocyanate compound to the polyol is less than 2. In one non-limiting embodiment, the reactive equivalent ratio (molar ratio or capping ratio) of the diisocyanate compound to the polyol is greater than 1 and less than 2.

[0023] The diamine compound is a chain extender for the high recovery polyurethane elastic fiber of the present disclosure. By using the diamine compound, high recovery can be achieved.

[0024] Non-limiting examples of diamine compounds that can be used include low molecular weight diamine compounds such as ethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2-methyl-1,5-pentanediamine, 1,5-pentanediamine, 1,2-diaminebutane, 1,3-diaminebutane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,2-dimethyl-1,3-diaminopropane, 1,3-diamino-2,2-dimethylbutane, 2,4-diamino-1-methylcyclohexane, 1,3-pentane Examples of suitable diamines include 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, bis(4-aminophenyl)phosphine oxide, hexamethylenediamine, 1,3-cyclohexyldiamine, hydrogenated metaphenylenediamine (HMPD), 2-methylpentamethylenediamine, 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,12-dodecanediamine, isophoronediamine, xylylenediamine, and bis(4-aminophenyl)phosphine oxide. These may be used alone or in combination. Low-molecular-weight diol compounds such as ethylene glycol may also be used in combination as long as the properties are not impaired.

[0025] Diamine compounds having 2 to 5 carbon atoms are preferred, and in consideration of elastic yarns having excellent elongation and elastic recovery, it is particularly preferred to use ethylenediamine or a diamine mixture containing at least 70 mol% ethylenediamine. In addition to these chain extenders, a triamine compound (diethylenetriamine, etc.) may be used to form a branched structure, as long as the effects of the present invention are not lost.

[0026] In one non-limiting embodiment, a diamine compound such as ethylenediamine or a mixture thereof with at least one diamine selected from the group consisting of aliphatic diamines and alicyclic diamines, each having 2 to 13 carbon atoms, is used.

[0027] In one non-limiting embodiment, the polyurethane polymer is chain extended with a diamine compound to provide an end group concentration of 5 to 50 mEq / kg of polymer solids.

[0028] A chain terminator can be used during the chain extension reaction to control the molecular weight of the resulting polyurethane polymer. In consideration of stabilizing the properties of the yarn after spinning, the molar ratio of the chain extender to the chain terminator is preferably 10 to 20, more preferably 14 to 18.

[0029] Non-limiting examples of chain terminators that can be used include monoalcohol compounds such as n-butanol, and monoamine compounds such as dimethylamine, diethylamine, n-propylamine, isopropylamine, n-butylamine, cyclohexylamine, and n-hexylamine, or mixtures thereof. Monoamine compounds are preferred, and diethylamine is more preferred. Chain terminators are usually used by blending them with chain extenders.

[0030] In one non-limiting embodiment, at least one monoamine, primary, or secondary selected from the group consisting of aliphatic amines and alicyclic amines, each having 2 to 12 carbon atoms, is used.

[0031] Non-limiting examples of high resilience polyurethane elastic fibers useful in the nonwoven laminates and articles of manufacture of the present disclosure are those described in U.S. Pat. No. 9,567,694, the disclosure of which is incorporated herein by reference in its entirety, and which consist of a polyol having a molecular weight of 450 to 1600, an organic diisocyanate compound, and a diamine compound.

[0032] When using solution polymerization, a poly(urethane urea) solution can be obtained by using polyols, organic diisocyanate compounds, diamine compounds, etc. as raw materials and polymerizing them in an organic solvent, such as DMAc, DMF, DMSO, NMP, or a solution using these as the main component. The reaction method is not particularly limited, and examples include a one-shot method in which each raw material is introduced into a solution, dissolved, and then heated to an appropriate temperature to cause reaction, and a prepolymer method in which a polyol and an organic diisocyanate compound are first reacted, and then the prepolymer is dissolved in a solvent and reacted with a diamine compound to chain extend, thereby forming a prepolymer in a non-solvent system to synthesize poly(urethane urea). The prepolymer method is preferred.

[0033] When synthesizing polyurethane, it is preferable to mix one or two catalysts such as an amine catalyst and an organometallic catalyst.

[0034] Examples of the amine catalyst include N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, triethylamine, N-methylmorpholine, N-ethylmorpholine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,3-propanediamine, N,N,N',N'-tetramethylhexanediamine, bis-2-dimethylamine ethyl ether, N,N,N',N'-pentamethyldiethylenetriamine, tetramethylguanidine, and triethylenediamine. , N,N'-dimethylpiperazine, N-methyl-N'-dimethylaminoethyl-piperazine, N-(2-dimethylaminoethyl)morpholine, 1-methylimidazole, 1,2-dimethylimidazole, N,N-dimethylaminoethanol, N,N,N'-trimethylaminoethylethanolamine, N-methyl-N'-(2-hydroxyethyl)piperazine, 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylaminihexanol, and triethanolamine.

[0035] In one non-limiting embodiment, high recovery polyurethane elastic fibers are spun from a solution-polymerized polyurethane polymer solution by a prepolymer process.

[0036] According to the present disclosure, high recovery polyurethane elastic fibers are used to elasticize nonwoven laminates. The high recovery polyurethane elastic fibers may be contained within the nonwoven laminate or juxtaposed with the nonwoven laminate.

[0037] In one non-limiting embodiment, the high recovery polyurethane elastic fibers are first stretched and then applied or incorporated into the nonwoven laminate in that stretched state.

[0038] This process of elasticizing nonwoven fabrics typically incorporates 2 to 50 or more edges into the nonwoven laminate. When adhesively bonded or juxtaposed within the nonwoven laminate, the elongated fibers are relaxed, thereby providing an elastic nonwoven laminate. In one non-limiting embodiment, the high-resilience polyurethane elastic fibers are stretched to a draft of about 3.0 to about 4.0 in at least one direction. The stretched nonwoven laminate is suitable for use in disposable hygiene products.

[0039] In one embodiment, the nonwoven laminate elasticized according to the present disclosure can be any type of flexible structure that can be used as or converted into a useful component for incorporation into or on a disposable hygiene product. Disposable personal hygiene products can be any product that helps promote, improve, enhance, or maintain the hygiene of the person or animal using the product. Non-limiting examples of disposable hygiene products include disposable diapers; training pants; adult incontinence products and products; feminine hygiene products, apparel, and products; bandages; wound dressings; surgical drapes, surgical gowns, surgical or other hygienic protective masks, hygienic gloves, head covers, headbands, ostomy bags, bed pads, bed sheets, etc.

[0040] Such products may or may not also be useful for absorbing bodily fluids. Products of this type are more commonly disposable in the sense that they are used only once or at most a few times and / or for a relatively short period of time and then discarded. They are generally not washed, wiped, re-careed or reconditioned, and are not subsequently reused.

[0041] Components made from the elasticized nonwoven laminates according to the process herein can be used as or in elements found in disposable hygiene products of the aforementioned types. Such elements can include, for example, the front, back, and side panels, leg cuffs, leg holes, abdominal bands, and / or waistbands of diapers or training pants. These hygiene product components can be prepared, for example, by converting the stretched nonwoven laminates prepared herein in bulk form into separate individual segments of a size and configuration suitable for incorporation into individual disposable personal hygiene products.

[0042] The stretchable nonwoven laminate prepared according to the process of the present invention will include at least one relatively inelastic nonwoven laminate. For purposes of this invention, the term "nonwoven laminate" is used interchangeably with the term "nonwoven substrate" and, in its broadest sense, is meant to include any flexible or deformable nonwoven substrate having at least one surface to which high-resilience polyurethane elastic fibers can be adhesively bonded. Such nonwoven laminates are generally flexible but relatively inelastic substrates with two surfaces, such as an upper and lower surface. By "relatively inelastic substrate" is meant a substrate that can be stretched up to about 120% in any direction without breaking, or that exhibits an increase in elongation length of more than 30% after stretching to 50% of the breaking elongation and removing the stretching force.

[0043] The relatively inelastic substrate for elasticization herein is in the form of a nonwoven substrate. A nonwoven substrate or "web" is a substrate having a structure of individual fibers, filaments, or threads that are woven together but not in a recognizable repeating pattern. Nonwoven substrates can be formed by a variety of conventional processes, such as, for example, meltblowing, spunbonding, and bonded carded web processes.

[0044] Meltblown substrates or webs are made from meltblown fibers. Meltblown fibers are formed by extruding molten thermoplastic material through a plurality of fine, usually circular, die capillaries into a high-velocity gas (e.g., air) stream as molten thermoplastic material or filaments. This attenuates the molten thermoplastic material filaments, reducing their diameter, which can be the diameter of microfibers. The meltblown fibers are then carried by the high-velocity gas stream and deposited on a collection surface to form a web of randomly distributed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241, which is incorporated herein by reference.

[0045] Spunbond substrates or "webs" are those made from spunbond fibers. Spunbond fibers are small-diameter fibers formed by extruding molten thermoplastic material as filaments through a plurality of fine, usually circular capillaries in a spinneret. The diameter of the extruded filaments is then rapidly reduced, for example, by eductive stretching or other well-known spunbonding mechanisms. The production of spunbond nonwoven webs is shown, for example, in U.S. Pat. Nos. 3,692,618 and 4,340,563, both of which are incorporated herein by reference.

[0046] The relatively inelastic laminates elasticized by the process of the present invention can be constructed from a wide variety of materials. Non-limiting examples of suitable materials include polyethylene, polypropylene, polyester (e.g., polyethylene terephthalate), polybutane, ethylene-propylene copolymers, polyamides, tetrablock polymers, styrene block copolymers, polyhexamethylene adipamide, poly-(oc-caproamide), polyhexamethylene sebacamide, polyvinyl, polystyrene, polyurethanes, polytrifluorochloroethylene, ethylene-vinyl acetate polymers, polyetheresters, cotton, rayon, linen, and nylon. Furthermore, combinations of such material types can be used to form the relatively inelastic laminates elasticized herein.

[0047] Preferred nonwoven laminates to be elasticized herein include structures such as polymeric spunbond nonwoven webs. 2 Particularly preferred are spunbond polyolefin nonwoven webs having a basis weight of about 10 to about 25 grams / m. More preferably, such structures have a basis weight of about 10 to about 25 grams / m. 2 The polypropylene spunbond nonwoven web has a basis weight of

[0048] In one non-limiting embodiment, high resilience polyurethane elastic fibers are adhesively bonded or attached to a relatively inelastic substrate that is to be elasticized. Adhesive bonding of high resilience polyurethane elastic fibers to such inelastic flexible substrates by the processes herein is generally effected by the use of conventional hot melt adhesives.

[0049] Conventional hot melt adhesives are typically thermoplastic polymers that exhibit high initial tack, provide good bond strength between components, and have good UV and thermal stability. Preferred hot melt adhesives will be pressure sensitive. Examples of suitable hot melt adhesives include those containing polymers selected from the group consisting of styrene-isoprene-styrene (SIS) copolymers; styrene-butadiene-styrene (SBS) copolymers; styrene-ethylene-butylene-styrene (SEBS) copolymers; ethylene-vinyl acetate (EVA) copolymers; amorphous poly-alpha-olefin (APAO) polymers and copolymers; and ethylene-styrene interpolymers (ESI). Styrene-isoprene-styrene (SIS) block copolymer-based adhesives are most preferred. Hot melt adhesives are commercially available. They are available from Bostik under designations such as H-2104, H-2494, H-4232, and H-20043, and from HB Fuller Company under designations such as HL-1486 and HL-1470.

[0050] According to the process of the present invention, in this non-limiting embodiment, the high recovery polyurethane elastic fibers described herein will be stretched in at least one direction while, in the stretched state, adhesively bonded to at least one of the relatively inelastic nonwoven laminates to be elasticized. Generally, in this step of the process, the high recovery polyurethane elastic fibers are stretched to a draft of greater than about 3.0X (200% stretch) to about 4.0X (300% stretch) prior to bonding to the relatively inelastic substrate.

[0051] The desired degree of drafting of the high-resilience polyurethane elastic fiber can be achieved by applying a stretching force to the fiber in the machine direction. In commercial manufacturing operations, such stretching force can be applied by adjusting the speed and / or tension of the high-resilience polyurethane elastic fiber supply roll and the take-up roll of the elasticized product being produced. A combination of tension rolls can also be used to provide or assist polyurethane stretching.

[0052] Also, generally simultaneously with providing the stretched, high recovery polyurethane elastic fibers, a relatively inelastic nonwoven substrate of at least one type described herein will be provided, the nonwoven substrate having the stretched, high recovery polyurethane elastic fibers adhesively bonded thereto, either within the substrate or juxtaposed thereto. Like the high recovery polyurethane elastic fibers, the nonelastic substrate material can be provided from a supply roll.

[0053] Often, high resilience polyurethane elastic fibers are bonded within or juxtaposed with multiple substrates to form multi-layer laminates. Preferred composite laminate structures of this type are described more fully below.

[0054] In one non-limiting embodiment, after or while the high resilience polyurethane elastic fiber is stretched, and before, during, or even after the high resilience polyurethane elastic fiber contacts the substrate to be elasticized, a hot melt adhesive is applied, e.g., sprayed or coated, onto one or more surfaces of the high resilience polyurethane elastic fiber and / or the substrate of the structure to be elasticized. The surfaces of the stretched high resilience polyurethane elastic fiber and the relatively inelastic substrate are then brought into contact and maintained in any suitable manner so that at least some adhesive material is interposed between at least some portions of the surfaces of the elements to be bonded to each other.

[0055] In one non-limiting embodiment, the hot melt adhesive is applied to the surface of the high-resilience polyurethane elastic fiber and / or substrate to be elasticized to form a continuous coating of adhesive on such surface. In practice, the hot melt adhesive can be applied in a variety of different ways. In one method, the molten adhesive can be deposited as a discontinuous web from a spray nozzle, a process known as meltblowing. In another method, the molten adhesive can be deposited as a solid stream from a nozzle that moves in a spiral as the materials to be bonded pass through the nozzle. This technique is known as spiral spraying. The adhesive dispensed by the spray nozzle in the meltblowing or spiral spraying process can be propelled through the nozzle by a jet of heated air, which can be externally heated to a temperature above the melting temperature of the adhesive. The adhesive can also be applied directly to fibers and / or nonwoven laminates by direct coating or jetting techniques, which apply a "dot matrix" pattern to any desired surface.

[0056] The temperature of the hot melt adhesive at the point of contact with the high resilience polyurethane elastic fiber depends on the temperature of the dispensed adhesive, the amount of adhesive used, the adhesive application technique, and the specific details of the physical layout of the system used to apply the adhesive. Because the temperature of the adhesive at its actual contact with the polyurethane fiber or film is difficult to measure, the temperature of the adhesive as it exits the application head is typically used as the basis for defining the adhesive temperature used in the processes herein. However, it is understood that the temperature of the adhesive as it contacts the polyurethane can range from essentially equal to the temperature of the adhesive as it exits the application head (e.g., slot coat or other strand application systems such as the SureWrap® system manufactured by Nordson, Inc.) to as much as 70°F to 150°F lower than the adhesive temperature as it exits the application head, such as in the case of spiral spray or meltblown application systems.

[0057] The temperature of the adhesive upon exiting the application head in the processes herein will generally be in the range of about 280°F to about 350°F. Preferably, the hot melt adhesive used should be provided with a melt temperature of about 300°F to about 325°F. Contact of a hot melt adhesive within such a temperature range with a polyurethane material can often cause the polyurethane temperature to reach values ​​within the range of about 125°F to about 300°F. At such temperatures, the selected polyurethane materials used herein, i.e., those based on poly(tetramethylene-co-alkylene ether) glycol, can be drafted to the extent specified herein without exhibiting unacceptable breakage of the high recovery polyurethane elastic fibers.

[0058] After the adhesive has been applied to a suitable surface, the high resilience polyurethane elastic fiber and the substrate to be elasticized are then maintained in contact with one another under conditions sufficient to adhesively bond the stretched high resilience polyurethane elastic fiber within or juxtaposed with the relatively inelastic substrate. This is generally accomplished by applying pressure to the contacted materials via the processing equipment used to form the adhesive bond between the materials. For example, the contacted high resilience polyurethane elastic fiber and nonwoven fabric can be passed through a pair of nip rolls before being further processed and / or wound onto a take-up roll.

[0059] After the high recovery polyurethane elastic fibers have been adhesively bonded in their elongated state within or juxtaposed to one or more relatively inelastic substrates, the resulting elasticized composite structure can be relaxed by removing the tension that has been keeping the polyurethane material elongated, thereby allowing the resulting elastic nonwoven laminate to contract, thereby forming a gathered or gathered composite structure that is stretchable and can be converted into an elastic component for a disposable hygiene product or garment.

[0060] In one particularly preferred embodiment, a composite nonwoven laminate is prepared that includes two outer layers of nonwoven substrates of substantially equal width and an inner layer of substantially parallel, evenly spaced, high-resilience polyurethane elastic fibers. Both of the nonwoven substrates used in this preferred composite nonwoven laminate can be made from synthetic polymer fibers, such as polyolefin, polyester, or polyamide fibers. These nonwoven substrates are often thermally bonded, spunbonded, or hydroentangled webs. They are typically fabricated at a density of about 10 to about 30 grams per square meter. 2 The three layers of such preferred composite laminate structures are bonded together by a hot melt adhesive composition that comprises from about 5% to about 50% by weight of the composite laminate structure. Preparation of the composite structures described herein can be carried out using conventional equipment and processing techniques. Such equipment and techniques are disclosed, for example, in U.S. Pat. Nos. 4,634,482, 4,720,415, 4,482,666, 6,491,776, and 6,713,415; U.S. Patent Publication No. 2002 / 0119722; and International Publication No. WO 80 / 00676, all of which are incorporated herein by reference.

[0061] The elastic nonwoven laminates prepared according to the processes herein can be used as, or subsequently converted into, stretchable components for use in articles of manufacture, such as disposable hygiene products. This conversion typically involves cutting the elastic nonwoven laminate to lengths and configurations appropriate for the particular type of hygiene product in which such components will be used. Such conversion procedures are conventional and can be performed during and at the preparation site of the composite structures herein. Alternatively, the preparation of the composite structures herein, and / or the conversion of such composite structures prepared elsewhere into hygiene products, can be performed in connection with the manufacture of disposable hygiene articles incorporating the elasticized components, for example, on, near, or as part of a diaper production line.

[0062] An alternative to using the aforementioned hot melt attach elastic adhesive is to use ultrasonic bonding or other thermomechanical means to melt the nonwoven substrate juxtaposed with or around the elongated fiber, trapping the fiber within the nonwoven substrate.

[0063] As will be understood by those skilled in the art upon reading this disclosure, other manufactured articles that include nonwoven laminates, namely diapers, can be enhanced with this technology to create new consumer value.

[0064] The following examples demonstrate the present disclosure and its ability to be used in the manufacture of diapers without or with reduced amounts of spandex or rubber fibers. The present invention is capable of other and different embodiments, and its several details can be modified in various obvious respects without departing from the scope and spirit of the invention. Accordingly, the examples should be considered illustrative and not limiting. [Example]

[0065] Having described embodiments of the present disclosure, the following examples generally describe some additional embodiments of the present disclosure. While embodiments of the present disclosure will be described in conjunction with the following examples and the corresponding text and figures, there is no intent to limit the embodiments of the present disclosure to this description. On the contrary, the intent is to cover all alternatives, modifications, and equivalents included within the spirit and scope of the embodiments of the present disclosure.

[0066] Materials List Terathane® PTMEG 1800 is a poly(tetramethylene ether) glycol with a number average molecular weight of 1800 grams / mole and is supplied by LYCRA Corporation (Wilmington, Delaware, United States).

[0067] Terathane® PTMEG 1400 is a poly(tetramethylene ether) glycol with a number average molecular weight of 1400 grams / mole and is supplied by LYCRA Corporation (Wilmington, Delaware, United States).

[0068] Terathane® PTMEG1000 is a poly(tetramethylene ether) glycol with a number average molecular weight of 1000 grams / mole and is supplied by LYCRA Corporation (Wilmington, Delaware, United States).

[0069] Terathane® PTMEG650 is a poly(tetramethylene ether) glycol with a number average molecular weight of 650 grams / mole and is supplied by LYCRA Corporation (Wilmington, Delaware, United States).

[0070] Isonate® 125MDR or MDI is a mixture of diphenylmethane diisocyanates containing 98% 4,4′-MDI isomer and 2% 2,4′-MDI isomer (commercially available from Dow Company, Midland, Michigan).

[0071] EDA represents ethylenediamine as a chain extender, DEA represents N,N-diethylamine as a chain terminator, and DMAc represents N,N-dimethylacetamide as a solvent.

[0072] Test Method Viscosity of the polymer solutions was determined according to the method of ASTM D1343-69 using a Model DV-8 falling ball viscometer (Duratech Corp., Waynesboro, VA) operated at 40°C and reported in poise.

[0073] The solid content in the polymer solution was measured by a microwave-heated moisture / solids analyzer, Smart System 5 (CEM Corp., Matthews, NC).

[0074] The percent isocyanate (NCO%) of the capped glycol prepolymer was determined using potentiometric titration according to the method of S. Siggia, "Quantitative Organic Analysis via Functional Group," 3rd Edition, Wiley & Sons, New York, pages 559-561 (1963).

[0075] The strength and elastic properties of spandex fibers were measured according to the general method of ASTM D2731-72. Three fibers, a 5.0 cm gauge length, and 0-300% extension cycles were used for each measurement. Samples were cycled five times at a constant extension rate of 50 centimeters per minute. The load force (1Tp200), the stress on the spandex at 200% extension during the first cycle, is reported as centiNewtons of a given decitex (cN / dtex). The unload force (5Tm200), the stress at 200% extension during the fifth unload cycle, is also reported in centiNewton force. The break elongation was measured at the sixth extension cycle.

[0076] Normalized recovery is expressed as the recovery at the fifth unloading cycle at 200% elongation (5TM200), which is normalized to the unit fineness of the fiber (i.e., decitex).

[0077] The percent set was also measured on samples that had been subjected to five 0-300% elongation / relaxation cycles. The percent set, SET%, was then calculated as: %SET=100×(L f -L o ) / L o It was calculated as:

[0078] In the formula, L o and L f is the fiber length when held straight without tension before and after each of the five stretch / relaxation cycles.

[0079] Stretch nonwoven laminates are fabricated for testing in a four-yarn lamination configuration by high-speed lamination to a nonwoven. A high-speed laminator is a device that produces nonwoven-spandex-nonwoven laminates using a process that simulates the process commonly used on high-speed diaper manufacturing lines. This type of nonwoven-spandex fiber-nonwoven laminate is typically made as part of a disposable diaper construction. In the high-speed laminator process, the spandex fibers are stretched to a specific draft (3.8X in this non-limiting example) or tension and guided in a parallel, uniformly spaced configuration directly above a low-basis-weight nonwoven sheet (commonly referred to as the backsheet). The hot-melt adhesive is applied using a standard spiral coating application technique, described below. The spandex fibers are then placed in direct contact with the nonwoven sheet, and a second nonwoven sheet (commonly known as the topsheet) is placed in direct contact with the bottomsheet / spandex fiber assembly. Thus, the components are laminated in the order top sheet-spandex fiber-bottom sheet, and the entire assembly is passed through nip rolls. In this example, the adhesive application technology used in the laminator is a SureWrap® nozzle manufactured by Nordson, Inc. of Dawsonville, Ga. In a setup using this type of equipment, the tip of the nozzle contacts the spandex fiber, and the spandex fiber at the adhesive application point can be 0.25 to 0.5 inches above the backsheet. The linear distance between the adhesive application point and the nip rolls is typically about 8 inches, and the linear speed of the machine can typically be run at 200 to 1,000 feet per minute. The various nonwoven, adhesive, and spandex materials used, along with the specific test conditions used in this example, are as follows: Nonwoven: 15 grams / m² manufactured by Avgol, Inc. 2 Spunbond polypropylene. Adhesive: Bostick, Inc. H-4232 or H-20043 Elastic Attachment Hot Melt Adhesive.

[0080] The strength and elastic properties of the stretch nonwoven laminate were measured using the same tensile testing equipment used for the spandex fiber analysis. A single laminate specimen, a 7.6 cm gauge length, and a 0-150% elongation cycle were used for each measurement. The specimen was subjected to three cycles at a constant elongation rate. During this test, the load and unload forces were recorded in centiNewtons at 10% intervals for all three cycles. An excerpt from this test data is reported in Figure 2, which details the selection of the load and unload data for the third cycle.

[0081] The laminate shrinkage force test (similar to Figure 3) is a modification of the method used for laminate cycling and utilizes standard tensile testing equipment. A 22-centimeter length of laminate pre-tensioned to 392 centiNewtons is clamped into a tensile testing apparatus with a 20-centimeter gauge length. The laminate sample is cycled three times at a constant extension rate, cycling to a load of 0 centiNewtons and then back to the initial gauge length. On the third cycle, the laminate shrinkage force is recorded at 5% shrinkage intervals from the initial gauge length to 50% shrinkage. [Example]

[0082] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1411 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) in a 3.62:1.00 weight ratio in a continuous polymerization reactor under favorable conditions at 80°C for 3 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 2.77 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.55. 124.40 grams of the resulting prepolymer was dissolved in 195.93 grams of DMAc at 60°C. 2.21 grams of ethylenediamine, 0.32 grams of diethylamine, and 73.83 grams of DMAc were added to the chain extender solution at 80°C with vigorous stirring to obtain a polymer solution with a viscosity of 32 wt%.

[0083] The polymer was blended with 94 parts by weight of polyurethane polymer solids and 6 parts by weight of additive solids to produce a spin concentrate solution. This was dry-spun at 640 m / min with a godet roller to winder speed ratio of 1.30 to produce a 530 dtex multifilament yarn. The mechanical properties of the resulting yarn are shown in Figure 1. The properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (repeated tensile test of four-edge laminate from 0 to 150% at 3.8X draft level) and Figure 3 (shrinkage force of pre-stretched laminate). [Example]

[0084] The same procedures and raw materials as in Example 1 were used, but the fiber conditions were adjusted to a spinning speed of 619 m / min with a godet roller to winder speed ratio of 1.25 to obtain a 600 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The laminate properties, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0085] The same procedures and raw materials as in Example 1 were used, but the fiber conditions were adjusted to a spinning speed of 488 m / min with a godet roller to winder speed ratio of 1.25, resulting in a 670 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The laminate properties, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0086] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1432 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) in a 3.55:1.00 weight ratio in a continuous polymerization reactor under favorable conditions at 80°C for 3 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 3.16 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.58. 130.62 grams of the resulting prepolymer was dissolved in 207.05 grams of DMAc at 60°C. To the chain extender solution, 2.50 grams of ethylenediamine, 0.32 grams of diethylamine, and 76.61 grams of DMAc were added with vigorous stirring at 80°C to obtain a 32 wt% polymer solution with a controlled viscosity.

[0087] The polymer was blended with 94 parts by weight of polyurethane polymer solids and 6 parts by weight of additive solids to produce a spin concentrate solution. This was dry-spun at 640 m / min with a godet roller to winder speed ratio of 1.30 to produce a 530 dtex multifilament yarn. The mechanical properties of the resulting yarn are shown in Figure 1. The properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (repeated tensile test of four-edge laminate from 0 to 150% at 3.8X draft level) and Figure 3 (shrinkage force of pre-stretched laminate). [Example]

[0088] The same procedures and raw materials as in Example 4 were used, but the fiber conditions were adjusted to a spinning speed of 558 m / min with a godet roller to winder speed ratio of 1.25 to obtain a 600 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The laminate properties, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0089] The same procedure and raw materials as in Example 4 were used, but the fiber conditions were adjusted to a spinning speed of 488 m / min with a godet roller to winder speed ratio of 1.25, resulting in a 670 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The resulting properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0090] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1402 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) in a 3.50:1.00 weight ratio in a continuous polymerization reactor under favorable conditions at 75°C for 4 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 3.13 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.60. 83.33 grams of the resulting prepolymer was dissolved in 132.70 grams of DMAc at 60°C. To the chain extender solution, 1.59 grams of ethylenediamine, 0.25 grams of diethylamine, and 56.88 grams of DMAc were added with vigorous stirring at 80°C to obtain a 31 wt% polymer solution with a controlled viscosity.

[0091] The polymer was blended with 96 parts by weight of polyurethane polymer solids and 4 parts by weight of additive solids to produce a spin concentrate solution. This was dry-spun at 549 m / min with a godet roller to winder speed ratio of 1.25 to produce a 600 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The resulting properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0092] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1432 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) in a 3.66:1.00 weight ratio in a continuous polymerization reactor under favorable conditions at 80°C for 3 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 2.79 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.53. 130.62 grams of the resulting prepolymer was dissolved in 180.69 grams of DMAc at 60°C. 2.31 grams of ethylenediamine, 0.32 grams of diethylamine, and 66.87 grams of DMAc were added to the chain extender solution at 80°C with vigorous stirring to obtain a 35 wt% polymer solution with a controlled viscosity.

[0093] The polymer was blended with 94 parts by weight of polyurethane polymer solids and 6 parts by weight of additive solids to produce a spin concentrate solution. This was dry-spun at 689 m / min with a godet roller to winder speed ratio of 1.25 to produce a 530 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The resulting properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0094] The same procedure and raw materials as in Example 8 were used, but the fiber conditions were adjusted to a spinning speed of 619 m / min with a godet roller to winder speed ratio of 1.25 to produce a 600 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The resulting properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0095] The same procedure and raw materials as in Example 8 were used, but the fiber conditions were adjusted to a spinning speed of 549 m / min with a godet roller to winder speed ratio of 1.25, resulting in a 670 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 1. The resulting properties of the laminate, along with those of a comparative commercial example, are shown in Figure 2 (0-150% cyclic tensile test of four-edge laminate at 3.8X draft level) and Figure 3 (pre-stretched laminate contraction force). [Example]

[0096] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 650 g / mol molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) at a 2.00:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 90°C for 2 hours. The residual isocyanate groups after the reaction were 2.60%. The capping ratio (molar ratio of isocyanate to glycol) was 1.30. 375.33 grams of the resulting prepolymer was dissolved in 669.81 grams of DMAc at 50°C, and 114.20 grams of a 2.0 meq / g ethylenediamine solution and 6.129 grams of a 2.0 meq / g diethylamine solution were added to the chain extender solution with vigorous stirring to obtain a polymer solution.

[0097] The resulting polymer solution was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0098] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) having a molecular weight of 650 g / mol with 4,4'-diphenylmethane diisocyanate (MDI) in a 1.92:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 90°C for 2 hours. The residual isocyanate groups after the reaction were 2.82%. The capping ratio (molar ratio of isocyanate to glycol) was 1.35. 380.22 grams of the obtained prepolymer was dissolved in 697.78 grams of DMAc at 50°C, and 133.78 grams of a 2.0 meq / g solution of ethylenediamine and 2-methyl-1,5-pentanediamine in a molar ratio of 9:1 and 4.87 grams of a 2.0 meq / g diethylamine solution were added to the chain extender solution with vigorous stirring to obtain a polymer solution.

[0099] The polymer was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0100] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 650 g / mol molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) at a 1.86:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 80°C for 3 hours. The residual isocyanate groups after the reaction were 3.36%. The capping ratio (molar ratio of isocyanate to glycol) was 1.40. 600.21 grams of the resulting prepolymer was dissolved in 1294.78 grams of DMAc at 50°C, and 149.04 grams of a 10 wt% ethylenediamine / DMAc solution and 8.78 grams of a 10 wt% diethylamine / DMAc solution were added to the chain extender solution with vigorous stirring to obtain a 30 wt% polymer solution. The concentration of the terminal group derived from the diamine compound was 19.5 meq / kg.

[0101] The resulting polymer solution was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0102] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) having a molecular weight of 1000 g / mol with 4,4'-diphenylmethane diisocyanate (MDI) in a 2.76:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 90°C for 2 hours. The residual isocyanate groups after the reaction were 2.775%. The capping ratio (molar ratio of isocyanate to glycol) was 1.45. 340.73 grams of the obtained prepolymer was dissolved in 632.51 grams of DMAc at 50°C, and 110.82 grams of a 2.0 meq / g solution of ethylenediamine and 2-methyl-1,5-pentanediamine in a molar ratio of 9:1 and 4.35 grams of a 2.0 meq / g diethylamine solution were added to the chain extender solution with vigorous stirring to obtain a polymer solution.

[0103] The polymer was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0104] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) having a molecular weight of 1000 g / mol with 4,4'-diphenylmethane diisocyanate (MDI) in a 2.66:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 90°C for 2 hours. The residual isocyanate groups after the reaction were 3.06%. The capping ratio (molar ratio of isocyanate to glycol) was 1.50. 343.88 grams of the obtained prepolymer was dissolved in 628.91 grams of DMAc at 50°C, and 123.35 grams of a 2.0 meq / g solution of ethylenediamine and 2-methyl-1,5-pentanediamine in a molar ratio of 9:1 and 4.75 grams of a 2.0 meq / g diethylamine solution were added to the chain extender solution with vigorous stirring to obtain a polymer solution.

[0105] The polymer was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0106] A prepolymer was obtained by reacting 1200 g / mol polytetramethylene ether glycol (PTMEG) (prepared by blending 62.5 parts by weight of 1000 g / mol PTMEG and 37.5 parts by weight of 1800 g / mol PTMEG) with 4,4'-diphenylmethane diisocyanate (MDI) in a 2.91:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 80°C for 3 hours. The residual isocyanate groups after the reaction were 3.38%. The capping ratio (molar ratio of isocyanate to glycol) was 1.65. 535 g of the obtained prepolymer was dissolved in 1152.04 g of DMAc at 50° C., and 133.92 g of a 10 wt % ethylenediamine / DMAc solution and 10.52 g of a 10 wt % diethylamine / DMAc solution were added to the chain extender solution with vigorous stirring to obtain a 30 wt % polymer solution. The concentration of end groups derived from the diamine compound was 26 meq / kg.

[0107] The resulting polymer solution was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0108] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1400 g / mol molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) at a 3.29:1.00 weight ratio in a 2 L Pyrex® glass vessel equipped with a continuous overhead stirrer, heater, and thermocouple temperature measurement device under favorable conditions at 80°C for 3 hours. The residual isocyanate groups after the reaction were 3.22 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.70. 520 grams of the resulting prepolymer was dissolved in 1122.66 grams of DMAc at 50°C. 123.86 grams of a 10 wt% ethylenediamine / DMAc solution and 12.16 grams of a 10 wt% diethylamine / DMAc solution were added to the chain extender solution with vigorous stirring to obtain a 30 wt% polymer solution. The end group concentration derived from the diamine compound was 31 meq / kg.

[0109] The resulting polymer solution was mixed with additives and spun into multifilament yarns, the mechanical properties of which are shown in Figure 1. [Example]

[0110] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1368 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) at a weight ratio of 3.54:1.00 under favorable conditions in a continuous polymerization reactor at 80°C for 3 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 2.72 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.543. 105.83 grams of the resulting prepolymer was dissolved in 146.40 grams of DMAc at 60°C. 1.88 grams of ethylenediamine, 0.26 grams of diethylamine, and 54.16 grams of DMAc were metered into the chain extender solution in the reactor at 80°C to obtain a polymer solution with a viscosity adjusted to a concentration of 35 wt%. It should be understood that the units reported in this example represent grams per minute in a continuous polymerization process.

[0111] The polymer was blended with 93.25 parts by weight of polyurethane polymer solids and 6.75 parts by weight of additive solids to form a spin concentrate, which was dry-spun at 914 m / min with a godet roller to winder speed ratio of 1.18 to produce a 33 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0112] The same procedure and raw materials as in Example 18 were used, but the fiber conditions were adjusted to a spinning speed of 869 m / min with a godet roller to winder speed ratio of 1.15 to obtain a 44 dtex multifilament yarn, the yarn mechanical properties of which are shown in Figure 4. [Example]

[0113] The same procedure and raw materials as in Example 18 were used, but the fiber conditions were adjusted to a spinning speed of 610 m / min with a godet roller to winder speed ratio of 1.18 to obtain a 78 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0114] A prepolymer was obtained by reacting polytetramethylene ether glycol (PTMEG) with 1409 g / mol of molecular weight and 4,4'-diphenylmethane diisocyanate (MDI) at a weight ratio of 3.62:1.00 under favorable conditions in a continuous polymerization reactor at 80°C for 3 hours at a specific reaction rate. The residual isocyanate groups after the reaction were 2.77 wt%. The capping ratio (molar ratio of isocyanate to glycol) was 1.556. 134.28 grams of the resulting prepolymer was dissolved in 185.76 grams of DMAc at 60°C. 2.38 grams of ethylenediamine, 0.33 grams of diethylamine, and 68.73 grams of DMAc were metered into the chain extender solution in the reactor at 80°C to obtain a polymer solution with a viscosity adjusted to a concentration of 35 wt%. It should be understood that the units reported in this example represent grams per minute in a continuous polymerization process.

[0115] The polymer was blended at 93.25 parts by weight of polyurethane polymer solids and 6.75 parts by weight of additive solids to form a spin concentrate, which was dry-spun at 975 m / min with a godet roller to winder speed ratio of 1.28 to produce a 350 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0116] The same procedure and raw materials as in Example 21 were used, but the fiber conditions were adjusted to a spinning speed of 869 m / min with a godet roller to winder speed ratio of 1.25 to obtain a 420 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0117] The same procedure and raw materials as in Example 21 were used, but the fiber conditions were adjusted to a spinning speed of 549 m / min with a godet roller to winder speed ratio of 1.25 to obtain a 670 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0118] The same procedure and raw materials as in Example 21 were used, but the fiber conditions were adjusted to a spinning speed of 457 m / min with a godet roller to winder speed ratio of 1.25 to obtain an 820 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4. [Example]

[0119] The same procedure and raw materials as in Example 21 were used, but the fiber conditions were adjusted to a spinning speed of 381 m / min with a godet roller to winder speed ratio of 1.25 to obtain a 950 dtex multifilament yarn. The yarn mechanical properties of the resulting yarn are shown in Figure 4.

Claims

1. A method for producing a stretchable nonwoven fabric laminate comprising high recovery polyurethane elastic fibers and a nonwoven fabric laminate, comprising: The high recovery polyurethane elastic fiber is produced from a polyol, an organic diisocyanate compound, and a diamine compound; The method for producing a stretchable nonwoven fabric laminate, wherein the polyol has a number average molecular weight of 450 to 1,600.

2. 2. The method for producing a stretchable nonwoven laminate according to claim 1, wherein the high recovery polyurethane elastic fibers are bonded within the nonwoven laminate or juxtaposed with the nonwoven laminate.

3. 10. The method of claim 1, wherein the high recovery polyurethane elastic fiber exhibits a normalized recovery force of at least 0.023 centiNewtons per decitex, expressed as the recovery force at 200% elongation for the fifth unload cycle.

4. The method for producing a stretchable nonwoven fabric laminate according to claim 1, wherein the high recovery polyurethane elastic fiber has a decitex of 30 to 1500.

5. The method for producing a stretchable nonwoven fabric laminate according to claim 1, wherein the high recovery polyurethane elastic fiber has a decitex of 33 to 1,100.

6. The method for producing a stretchable nonwoven fabric laminate according to any one of claims 1 to 5, wherein the high recovery polyurethane elastic fiber is bonded within the nonwoven fabric laminate or juxtaposed with the nonwoven fabric laminate via a hot melt adhesive.

7. The method for producing a stretchable nonwoven fabric laminate according to any one of claims 1 to 5, wherein the high recovery polyurethane elastic fibers are encapsulated within the nonwoven fabric laminate or juxtaposed with the nonwoven fabric laminate by ultrasonic or thermomechanical methods.

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