TH34003A - Modified cellulose fiber And membranes of these fibers - Google Patents

Abstract

The disclosed DC60 (06/11/11) is a cellulose fiber with a dry tensile index (DSI) of zero, i.e., considered to be lower than the DSI of its corresponding unmodified cellulose fiber. Fibers with a DSI may provide a fiber structure that improves hand feel compared to fibers prepared from unmodified fibers. Specifically, these modified fibers exhibit an improved bending fiber structure, observed by improved softness and a reduced DSI. This is typically achieved by reacting the fibers with one or more cellulase enzymes and one or more anti-binding agents. Fabrication also involves a fiber structure with a density no greater than approximately 0.4 g/cm³, which is bent and constructed from modified cellulose fibers with a DSI lower than the DSI of the cellulose fiber. The modified fibers, that is, those with a corresponding tensile strength of at least approximately 15% less, and whose fiber structure has a tensile strength of at least approximately 30% less than the tensile strength of at least approximately 30% less than the disclosed ... The fiber structure consists of modified cellulose fibers with a dry tensile strength index of zero of the corresponding unmodified cellulose fibers, i.e., at least approximately 15% less, and the fiber structure has a dry tensile bending modulus less than the dry tensile bending modulus of the fiber structure prepared from the corresponding unmodified fibers, i.e., at least approximately 30% less.

Claims (15)

1. Modified cellulose fibers that have a zero-span dry tensile strength index (DSD) less than the corresponding unmodified cellulose fiber by at least 35%. 2. Modified cellulose fibers exhibiting a tensile strength index (TSE) at zero dry interval to a tensile strength index (TSE) at zero wet interval ranging from 1.5 to 3. 3. Cellulose fibers modified according to claim 1 or 2, which have a dry tensile strength index (Zero Strain) less than the dry tensile strength index (Zero Strain) of the corresponding unmodified cellulose fiber, i.e., at least 40% less, preferably at least 45%. 4. Modified cellulose fibers according to claim 1, characterized as selected from groups consisting of modified northern, southern, and equatorial softwood draft fibers; groups consisting of modified northern softwood draft fibers; modified southern softwood draft fibers; and mixtures of these fibers; modified northern hardwood draft fibers; southern and equatorial hardwood draft fibers; modified northern, southern, and equatorial hardwood sulfite fibers; and modified northern, southern, and equatorial softwood sulfite fibers; and mixtures of these fibers. 5. Cellulose fibers modified according to one of the claims 1-4, which are characterized as being prepared by combining one or more cellulase enzymes and cellulose fibers and allowing this combination to react for a period of time sufficient to reduce the tensile strength index at dry zero of the fiber by at least 35%. 6. The fibrous structure, with a density not exceeding 0.4 g/cm³, exhibits the characteristic feature that the fibrous structure consists of modified cellulose fibers with a tensile strength index (TSI) of zero dry span compared to the corresponding modified wood fibers, i.e., at least 15% less. Furthermore, it exhibits the characteristic feature that the fibrous structure has a bending modulus per dry tensile strength less than the bending modulus per dry tensile strength of the fibrous structure prepared from the corresponding modified wood fibers, i.e., at least 30% less. 7. The fiber structure according to claim paragraph 6 is characterized as follows: The fiber structure consists of modified cellulose fibers which have a dry zero-span tensile index less than the dry zero-span tensile index of the corresponding unmodified cellulose fibers, i.e., at least 20% less, preferably at least 25%; and it is further characterized as follows: The fiber structure has a dry tensile bending adulus less than the dry tensile bending modulus of the fiber structure prepared from the corresponding unmodified fibers, i.e., at least 35% less, preferably at least 40%. 8. The fiber structure according to claim 6 or 7, which is characterized by the selection of modified fibers from a group consisting of modified northern, southern, and equatorial softwood drafts; modified northern, southern, and equatorial hardwood drafts; modified northern, southern, and equatorial hardwood sulfite drafts; modified northern, southern, and equatorial softwood sulfite drafts; and a mixture of these drafts. 9. The fiber structure of one of the claims in Clauses 6-8, which characterizes that the handsheet must consist of modified cellulose fibers whose dry tensile index is at least 90% of the dry tensile index of the corresponding handsheet which must consist of the corresponding unmodified cellulose fibers, is preferred to be at least 5% higher than the dry tensile index of the corresponding handsheet which must consist of the corresponding unmodified cellulose fibers. 10. Method for preparing modified cellulose fibers: The method involves combining one or more cellulose enzymes and cellulose fibers, and allowing the mixture to react for a sufficient period to reduce the tensile strength at zero range at dry of the fiber by at least 35% compared to the tensile strength at zero range at dry of a corresponding unmodified fiber. 11. The method described in claim 10, which characterizes that the debonding agent reacts with the yarn fibers. 12. The method under claim 10 or 11, which is characterized by the combination of one or more enzymes belonging to the 45 cellulose genera with cellulose fibers, typically involves the selection of one or more enzymes from a group comprising endoglucanases EG V, Celluelast R, Celluzyne R, Pergolase R, and a combination of these enzymes. 13. The method described in claim 11, which is characterized by the incorporation of one or more anti-stretching agents into cellulose fibers after the fibers have been treated with one or more enzymes. 14. The method described in claims 11 or 13, which is characterized by the incorporation of one or more anti-binding agents into the fibers at a level of at least 1% relative to the dry weight of the modified fibers. 15. The method described in Claim 11, 13, or 14, which is characterized by the selection of one or more binding agents from a group of saturated and unsaturated fatty acids and fatty acid salts, alkenyl succinic anhydride, alkenyl succinic acid, alkenyl sulfinate salts, sorbitan mono-, di- and triester, tertiary amines and their derivatives, amine oxides, quaternary amines, silicone-based compounds, clay particles, silicate particles, and a mixture of these (Claim 15, 3 pages, 0 images).