Nonwoven webs comprising polysaccharides
AssigneeDupont Industrial Biosciences USA, LLC
InventorsNatnael Behabtu, Monica Harvey, Christian Peter Lenges, Ian Robert Beardsall
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Abstract
Disclosed herein are nonwoven webs comprising a nonwoven substrate and a binder comprising a polysaccharide. In one embodiment, the polysaccharide can comprise poly alpha-1,3-glucan, a poly alpha-1,3-glucan ether compound as disclosed herein, a poly alpha-1,3-glucan ester compound as disclosed herein, a graft copolymer comprising a backbone comprising dextran and poly alpha-1,3-glucan side chains, a crosslinked graft copolymer comprising a backbone comprising dextran and poly alpha-1,3-glucan chains, or a mixture thereof. Also disclosed are articles comprising the nonwoven webs, and methods of making the nonwoven webs.
Claims15
A nonwoven web comprising:
- a nonwoven substrate and a binder comprising a polysaccharide, wherein the polysaccharide comprises:
- a) poly alpha-1,3-glucan;
- b) a poly alpha-1,3-glucan ether compound represented by Structure I:
- wherein
- (i) n is at least 6,
- (ii) each R is independently an H or a positively charged organic group, and
- (iii) the compound has a degree of substitution of about 0.001 to about 3.0;
- c) a graft copolymer comprising:
- (i) a backbone comprising dextran with a weight-average molecular weight (Mw) of at least about 100000 Daltons, and
- (ii) poly alpha-1,3-glucan side chains comprising at least about 95% alpha-1,3-glucosidic linkages;
- d) a crosslinked graft copolymer, wherein the graft copolymer portion of the crosslinked graft copolymer comprises:
- (i) a backbone comprising dextran, and
- (ii) poly alpha-1,3-glucan side chains comprising at least about 50% alpha-1,3-glucosidic linkages;
- e) a poly alpha-1,3-glucan ester compound represented by Structure III:
- wherein
- (i) n is at least 6;
- (ii) each R is independently an —H or a first group comprising —CO—Cx—COOH, wherein the —Cx— portion of said first group comprises a chain of 2 to 6 carbon atoms;
- and
- (iii) the compound has a degree of substitution with the first group of about 0.001 to about 3;
- or
- f) a combination thereof.
A process for preparing a nonwoven web, the process comprising the steps:
- a) providing a nonwoven substrate having a first surface and comprising side-by-side or sheath/core bicomponent fibers comprising a polyethylene/polyethylene terephthalate composition or at least one of polyolefin, polytetrafluoroethylene, polyester, polyvinyl acetate, polyvinyl chloride acetate, polyvinyl butyral, acrylic resins, polymethylacrylate, polymethylmethacrylate, polyamide, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyurethane, or cellulosic resins;
- b) providing a polysaccharide comprising:
- A) a graft copolymer comprising:
- (i) a backbone comprising dextran with a weight-average molecular weight (Mw) of at least about 100000 Daltons, and
- (ii) poly alpha-1,3-glucan side chains comprising at least about 95% alpha-1,3-glucosidic linkages;
- and/or
- B) a crosslinked graft copolymer, wherein the graft copolymer portion of the crosslinked graft copolymer comprises:
- (i) a backbone comprising dextran, and
- (ii) poly alpha-1,3-glucan side chains comprising at least about 50% alpha-1,3-glucosidic linkages;
- c) contacting at least a portion of the first surface of the nonwoven substrate with the polysaccharide;
- d) heating the material obtained in step c) at a temperature in the range of about 90° C. to about 170° C. to form a bonded nonwoven web comprising the polysaccharide;
- and
- e) optionally, calendaring the bonded nonwoven web obtained in step d).
Dependencies are inferred from the claim text.