Dow Global Technolgoies LLC

Ashish Sen

Rajen M Patel

Hongyu Chen

Shih-Yaw Lai

John Klier

Yuen-Yuen D Chiu

Yunwa Wilson Cheung

Antonios K Doufas

Andy Cheng Chang

Benjamin C Poon

Hong Peng

Thoi H Ho

Rexford Allison Maugans

Kenneth Stewart, Jr

Mladen Ladika

Antonio Batistini

Nancy J Schrock

Erin D O'Driscoll

Yeun-Yuen D Chiu

The present invention relates to crosslinked, olefin elastic fibers where the olefin materials are specifically selected to provide a more robust fiber with higher tenacity and greater temperature stability. Such fibers will be less subject to breakage during fiber spinning and post-spinning (downstream processing) operations including spool formation and unwinding. The specific olefin material used is a blend having an overall melt index (I2) of less than 2.5 g/10 min before crosslinking with a density in the range of 0.865 to 0.885 g/cm. One component of the blend will be characterized as having either a density in the range of from 0.855 to 0.88 g/cmor a residual crystallinity at 80&#xb0; C. of greater than 9 percent but not both. The at least one other component will meet at least whichever characteristic the first component does not meet.

Crosslinked polyethylene elastic fibers

A fiber is obtainable from or comprises an ethylene/&#x3b1;-olefin interpolymer characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle and a density, d, in grams/cubic centimeter, wherein the elastic recovery and the density satisfy the following relationship: Re&#x3e;1481&#x2212;1629(d). Such interpolymer can also be characterized by other properties. The fibers made therefrom have a relatively high elastic recovery and a relatively low coefficient of friction. The fibers can be cross-linked, if desired. Woven or non-woven fabrics can be made from such fibers.

Fibers made from copolymers of ethylene/&#x3b1;-olefins

A fiber is obtainable from or comprises an ethylene/&#x3b1;-olefin interpolymer characterized by an elastic recovery, Re, in percent at 300 percent strain and () cycle and a density, d, in grams/cubic centimeter, wherein the elastic recovery and the density satisfy the following relationship: Re&#x3e;1481&#x2212;1629(). Such interpolymer can also be characterized by other properties. The fibers made therefrom have a relatively high elastic recovery and a relatively low coefficient of friction. The fibers can be cross-linked, if desired. Woven or non-woven fabrics can be made from such fibers.

Fibers having improved resistance to moisture at elevated temperatures comprise at least two elastic polymers, one polymer heat-settable and the other polymer heat-resistant, the heat-resistant polymer comprising at least a portion of the exterior surface of the fiber. The fibers typically have a bicomponent and/or a biconstituent core/sheath morphology. Typically, the core comprises an elastic thermoplastic urethane, and the sheath comprises a homogeneously branched polyolefin, preferably a homogeneously branched substantially linear ethylene polymer.

Elastic, heat and moisture resistant bicomponent and biconstituent fibers

A fiber is obtainable from or comprises a propylene/&#x3b1;-olefin interpolymer characterized by an elastic recovery, Re, in percent at 300 percent strain and 1 cycle and a density, d, in grams/cubic centimeter, wherein the elastic recovery and the density satisfy the following relationship: Re&#x3e;1481-1629 (d). Such interpolymer can also be characterized by other properties. The fibers made therefrom have a relatively high elastic recovery and a relatively low coefficient of friction. The fibers can be cross-linked, if desired. Woven or non-woven fabrics can be made from such fibers.

Fibers made from copolymers of propylene/&#x3b1;-olefins

The elasticity of elastic, absorbent structures, e.g., diapers, is improved without a significant compromise of the absorbency of the structure by the use of bicomponent and/or biconstituent elastic fiber. The absorbent structures typically comprise a staple fiber, e.g., cellulose fibers, and a bicomponent and/or a biconstituent elastic. The bicomponent fiber typically has a core/sheath construction. The core comprises an elastic thermoplastic elastomer, preferably a TPU, and the sheath comprises a homogeneously branched polyolefin, preferably a homogeneously branched substantially linear ethylene polymer. In various embodiments of the invention, the elasticity is improved by preparation techniques that enhance the ratio of elastic fiber:cellulose fiber versus cellulose fiber:cellulose fiber bonding. These techniques include wet and dry high intensity agitation of the elastic fibers prior to mixing with the cellulose fibers, deactivation of hydrogen bonding between cellulose fibers, and grafting the elastic fiber with a polar group containing compound, e.g. maleic anhydride.

Elastic bicomponent and biconstituent fibers, and methods of making cellulosic structures from the same

The elasticity of elastic, absorbent structures, e.g., diapers, is improved without a significant compromise of the absorbency of the structure by the use of bicomponent and/or biconstituent elastic fibers. The absorbent structures typically comprise a staple fiber, e.g., cellulose fibers, and a bicomponent and/or a biconstituent elastic. The bicomponent fiber typically has a core/sheath construction. The core comprises an elastic thermoplastic elastomer, preferably a TPU, and the sheath comprises a homogeneously branched polyolefin, preferably a homogeneously branched substantially linear ethylene polymer. In various embodiments of the invention, the elasticity is improved by preparation techniques that enhance the ratio of elastic fiber:cellulose fiber bonding versus cellulose fiber:cellulose fiber bonding. These techniques include wet and dry high intensity agitation of the elastic fibers prior to mixing with the cellulose fibers, deactivation of the hydrogen bonding between cellulose fibers, and grafting the elastic fiber with a polar group containing compound, e.g. maleic anhydride.

Elastic fibers are described that comprise (i) a polyolefin polymer, e.g., a homogeneously branched, preferably substantially linear, ethylene polymer, and (ii) a photoinitiator, e.g., an aromatic ketone, in an amount sufficient to effect at least a partial cross-linking of the polymer when the fiber is exposed to sufficient UV-radiation to activate the photoinitiator. Articles, e.g., fabrics, comprising fibers of this invention, either alone or in combination with one or more other fibers, e.g., cellulose, nylon, etc., exhibit good heat resistance and elasticity at elevated temperatures.

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Lake Jackson, TX, United States of America

Ashish Sen