Melt spinning of blended cellulose acetate butyrate fibers

Abstract

Methods of preparing fibers comprising cellulose esters are described. The fibers include bicomponent core-sheath fibers where the core comprises one or more cellulose esters and the sheath comprises a polyolefin prepared by co-extrusion of mixtures comprising a cellulose ester and mixtures comprising a polyolefin, as well as substantially solid body fibers prepared by melt-spinning a mixture comprising one or more cellulose ester and a meltable solvent. Also described are fibers comprising cellulose esters, e.g., the fibers prepared by the disclosed methods, and related articles, such as textiles, clothing, synthetic fibers, and faux fur. The fibers can include colorants (e.g., colorants derived from natural materials) and/or flame retardants.

1 . A method of preparing a fiber, wherein the method comprises:
 (a) preparing a first mixture of solids comprising one or more cellulose esters;   (b) preparing a second mixture of solids comprising a polyolefin; and   (c) co-extruding said first mixture of solids and said second mixture of solids to prepare a bicomponent core-sheath fiber comprising a core comprising said first mixture of solids and a sheath comprising said second mixture of solids.   
     
     
         2 . The method of  claim 1 , wherein the one or more cellulose esters comprise or consist of cellulose acetate butyrate (CAB). 
     
     
         3 . The method of  claim 1 , wherein the first mixture of solids and/or the second mixture of solids further comprises one or more coloring agents, optionally wherein one or more of the one or more coloring agents is a flame retardant. 
     
     
         4 . The method of  claim 3 , wherein at least one of the one or more coloring agents is selected from the group consisting of a mineral, an animal product, and a plant product. 
     
     
         5 . The method of  claim 4 , wherein at least one of the one or more coloring agents is selected from the group consisting of bone black, an iron oxide, and mica. 
     
     
         6 . The method of  claim 1 , wherein the second mixture of solids comprises a bio-derived polyolefin, optionally a bio-derived polyethylene. 
     
     
         7 . The method of  claim 1 , wherein the second mixture of solids comprises polyethylene, optionally a bio-derived polyethylene, and one or more coloring agents, optionally bone black. 
     
     
         8 . The method of  claim 1 , wherein the first mixture of solids consists of CAB and the second mixture of solids consists of bio-derived polyethylene and about 5 weight (wt) % bone black. 
     
     
         9 . The method of  claim 1 , wherein the bicomponent fiber is a concentric or eccentric core-sheath fiber. 
     
     
         10 . The method of  claim 1 , wherein the weight ratio of core to sheath is about 60:40 to about 80:20. 
     
     
         11 . A fiber prepared according to the method of  claim 1 . 
     
     
         12 . A biocomponent fiber comprising:
 a core region comprising a first component comprising one or more cellulose esters; and   a sheath region at least partially surrounding the core region comprising a second component comprising a polyolefin.   
     
     
         13 . The bicomponent fiber of  claim 12 , wherein the first component comprises or consists of CAB. 
     
     
         14 . The bicomponent fiber of  claim 12 , wherein the second component comprises polyethylene, optionally a bio-derived polyethylene. 
     
     
         15 . The bicomponent fiber of  claim 12 , wherein the first component and/or the second component further comprises one or more coloring agents, optionally wherein one or more of the one or more coloring agents is a flame retardant. 
     
     
         16 . The bicomponent fiber of  claim 15 , wherein at least one of the one or more coloring agents is selected from the group consisting of a mineral, an animal product, and a plant product. 
     
     
         17 . The bicomponent fiber of  claim 16 , wherein at least one of the one or more coloring agents is selected from the group consisting of bone black, an iron oxide, and mica. 
     
     
         18 . The bicomponent fiber of  claim 12 , wherein the core-sheath bicomponent fiber is a concentric core-sheath bicomponent fiber. 
     
     
         19 . The bicomponent fiber of  claim 12 , wherein the weight ratio of core to sheath is about 60:40 to about 80:20. 
     
     
         20 . The bicomponent fiber of  claim 12 , wherein the core consists of CAB and the sheath consists of polyethylene with 5 wt % bone black, optionally wherein the polyethylene is a bioderived polyethylene. 
     
     
         21 . The bicomponent fiber of  claim 12 , wherein the bicomponent fiber has a linear density of about 35 grams per 9000 meters to about 70 grams per 9000 meters. 
     
     
         22 . A method of preparing a fiber, wherein the method comprises:
 (i) preparing a mixture of solids comprising one or more cellulose esters and a meltable solvent; and   (ii) melt-spinning said mixture of solids, thereby preparing a fiber comprising a substantially solid body.   
     
     
         23 . The method of  claim 22 , wherein the meltable solvent comprises or consists of dimethyl sulfone (DMSO-2). 
     
     
         24 . The method of  claim 22 , wherein the one or more cellulose esters comprises cellulose acetate butyrate (CAB). 
     
     
         25 . The method of  claim 24 , wherein the mixture of solids comprises CAB and DMSO-2 in a weight ratio CAB: DMSO-2 of about 1:1 to about 7:3. 
     
     
         26 . The method of  claim 24 , wherein the one or more cellulose esters further comprises at least one additional cellulose ester, optionally cellulose acetate (CA). 
     
     
         27 . The method of  claim 22 , wherein the mixture of solids further comprises a plasticizer, optionally wherein the plasticizer is selected from a phthalate, optionally dioctyl phthalate (DOP); a biodegradable citrate, optionally acetyl triethyl citrate or tributyl citrate; glycerol; an organic acid, optionally tartaric acid or mucic acid; and mixtures thereof. 
     
     
         28 . The method of  claim 22 , wherein the mixture of solids further comprises one or more coloring agents, optionally wherein one or more of the one or more coloring agents is a flame retardant. 
     
     
         29 . The method of  claim 28 , wherein at least one of the one or more coloring agents is selected from the group consisting of a mineral, an animal product, and a plant product. 
     
     
         30 . The method of  claim 29 , wherein the mixture of solids further comprises bone black, an iron oxide, and/or mica, optionally wherein the mixture of solids comprises about 0.5 wt % to about 10 wt % of bone black, an iron oxide, and/or mica. 
     
     
         31 . The method of  claim 22 , wherein the mixture of solids further comprises lignin, optionally wherein the mixture of solids comprises about 5 weight % (wt%) to about 30 wt % lignin. 
     
     
         32 . The method of  claim 22 , wherein the mixture of solids comprises a cellulose blend, said cellulose blend comprising about 10 wt % to about 21 wt % CA, about 50 wt % to about 65 wt % CAB, and about 10 wt % to about 21 wt % DMSO-2, and about 5 wt % to about 12 wt % of bone black, lignin, or a combination of bone black and lignin. 
     
     
         33 . The method of  claim 22 , wherein the mixture of solids further comprises cyclodextrin (CD), optionally wherein the mixture of solids comprises about 10 wt % CD. 
     
     
         34 . The method of  claim 22 , wherein the mixture of solids further comprises a non-coloring agent flame retardant, optionally an organophosphate, further optionally wherein the flame retardant is a polymeric polyphosphate or is provided in the form of an inclusion complex (IC) with CD. 
     
     
         35 . The method of  claim 34 , wherein the flame retardant is 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and the DOPO is provided in the form of an inclusion complex with CD (DOPO-IC), optionally wherein the mixture of solids comprises about 10 wt % DOPO-IC. 
     
     
         36 . The method of  claim 22 , wherein step (a) comprises melt compounding the mixture of solids, optionally using a twin-screw extruder, further optionally at a temperature between about 140 degrees Celsius (° C.) and about 180° C. 
     
     
         37 . The method of  claim 22 , wherein the melt-spinning is performed at a temperature of between about 150° C. and about 210° C. 
     
     
         38 . The method of  claim 37 , wherein the melt-spinning is performed at a take-up speed of about 20 to about 270 meters per minute (m/min). 
     
     
         39 . The method of  claim 22 , wherein the method further comprises drawing the fiber at an elevated temperature after the melt-spinning. 
     
     
         40 . The method of  claim 22 , wherein the method further comprises removing the meltable solvent after the melt-spinning. 
     
     
         41 . The method of  claim 40 , wherein removing the meltable solvent comprises pulling the fiber through a water bath under tension, optionally wherein the water bath is at a temperature between about 60° C. and about 80° C., optionally wherein the fiber has a dwell time in the water bath of at least about 45 seconds. 
     
     
         42 . A solid, nonporous fiber prepared according to the method of  claim 22 . 
     
     
         43 . The fiber of  claim 42 , wherein the fiber has a linear density of about 70 grams per 9000 meters to about 220 grams per 9000 meters. 
     
     
         44 . A yarn prepared from the bicomponent fiber of  claim 11 . 
     
     
         45 . A fabric prepared from the yarn of  claim 44 , optionally wherein the fabric is a non-woven fabric. 
     
     
         46 . An article of manufacture comprising a bicomponent fiber of  claim 11 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur. 
     
     
         47 . The article of manufacture of  claim 46 , wherein the article of manufacture is biodegradable and/or sustainable. 
     
     
         48 . The article of manufacture of  claim 46 , wherein the article of manufacture is self-extinguishing. 
     
     
         49 . A yarn prepared from the fiber of  claim 42 . 
     
     
         50 . A fabric prepared from the yarn of  claim 49 , optionally wherein the fabric is a non-woven fabric. 
     
     
         51 . An article of manufacture comprising the fiber of  claim 42 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur. 
     
     
         52 . An article of manufacture comprising the yarn of  claim 44 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur. 
     
     
         53 . An article of manufacture comprising the fabric of  claim 45 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur. 
     
     
         54 . An article of manufacture comprising the yarn of  claim 49 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur. 
     
     
         55 . An article of manufacture comprising the fabric of  claim 50 , optionally wherein the article of manufacture is selected from the group consisting of an article of clothing, a textile, synthetic hair, or faux fur.