US 10,718,069 B2Granted

Modified polylactic acid fibers

AssigneeKimberly-Clark Worldwide, Inc.

InventorsVasily A. Topolkaraev, Ryan J. McEneany, Thomas A. Eby, Tyler J. Lark

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Abstract

A method for forming biodegradable fibers is provided. The method includes blending polylactic acid with a polyepoxide modifier to form a thermoplastic composition, extruding the thermoplastic composition through a die, and thereafter passing the extruded composition through a die to form a fiber. Without intending to be limited by theory, it is believed that the polyepoxide modifier reacts with the polylactic acid and results in branching of its polymer backbone, thereby improving its melt strength and stability during fiber spinning without significantly reducing glass transition temperature. The reaction-induced branching can also increase molecular weight, which may lead to improved fiber ductility and the ability to better dissipate energy when subjected to an elongation force. Through selective control over this method, the present inventors have discovered that the resulting fibers may exhibit good mechanical properties, both during and after melt spinning.

Claims11

Dependent claims

A polylactic acid fiber having an average diameter of from about 5 to about 25 micrometers, the fiber comprising

a thermoplastic composition formed by melt blending and reacting polylactic acid with a polyepoxide modifier including a copolymer that contains an epoxy modified (meth)acrylic monomeric component and an olefin monomeric component
wherein the thermoplastic composition comprises 70 wt. % or more of the polylactic acid,
and further comprises a polymeric toughening additive in an amount of from 1 wt. % to 25 wt. %,
wherein the thermoplastic composition comprises a plurality of discrete domains dispersed within a continuous phase, at least some of the discrete domains containing the polyepoxide modifier, at least some of the discrete domains containing the polymeric toughening additive and having a length dimension of from about 0.5 μm to about 30 μm, and the continuous phase containing the polylactic acid, and
wherein the fiber has a glass transition temperature of from about 55° C. to about 65° C., and exhibits a peak elongation of about 50% or more and a tenacity of from about 0.75 to about 6 grams-force per denier.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/521,511Filed 23 Oct 2014 · division
Priority: 13 Aug 2010
Published: US 2015/0044929 A112 Feb 2015
Granted: 21 Jul 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification26 codes

D01F 6/625
From polyesters: derived from hydroxy-carboxylic acids, e.g. lactones
B29C 48/16
Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor: articles…
C08G 63/08
Derived from hydroxycarboxylic acids: lactones or lactides
C08L 67/04
Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain ; Compositions of derivatives of such polymers:…

Family

Application12/856,012Parent of this division · filed 13 Aug 2010
US 2015/0044929 A1Pre-grant publication · published 12 Feb 2015
US 8,936,740 B2Parent of this division
US 2012/0040582 A1Published application
US 10,718,069 B2This patent

From the US filing history. Foreign family members aren’t listed.