Continuous production of keratin fibers

Abstract

This disclosure relates to processes for preparing a keratin fiber, for example, continuous process. In some embodiments, a process as described herein can comprise extruding a keratin solution into a first solution to form a first fiber; drawing the first fiber and oxidizing the first fiber to form a treated fiber; drawing the treated fiber and oxidizing the treated fiber one or more times; and setting the treated fiber to form the keratin fiber. Such processes can be useful for preparing a keratin fiber with a high draw ratio.

What is claimed is: 
     
         1 . A process for preparing a keratin fiber, comprising:
 (i) extruding a keratin solution into a first solution to form a first fiber;   (ii) drawing the first fiber and oxidizing the first fiber to form a treated fiber;   (iii) drawing the treated fiber and oxidizing the treated fiber one or more times; and   (iv) setting the treated fiber to form the keratin fiber.   
     
     
         2 . The process according to  claim 1 , wherein the keratin fiber has a draw ratio of at least about 500%. 
     
     
         3 . The process according to  claim 1  or  2 , wherein the keratin fiber has a draw ratio of about 800% to about 2000%. 
     
     
         4 . The process according to any one of  claims 1 - 3 , wherein the keratin fiber has a draw ratio of about 1500%. 
     
     
         5 . The process according to any one of  claims 1 - 4 , wherein the diameter of the keratin fiber is about 5 micrometers to about 30 micrometers. 
     
     
         6 . The process according to any one of  claims 1 - 5 , wherein the diameter of the keratin fiber is about 15 micrometers. 
     
     
         7 . The process according to any one of  claims 1 - 6 , wherein the keratin fiber comprises at least about 70% keratin. 
     
     
         8 . The process according to any one of  claims 1 - 7 , wherein the keratin fiber comprises at least about 85% keratin. 
     
     
         9 . The process according to any one of  claims 1 - 8 , wherein the keratin fiber has a tenacity of at least about 0.8 g/den. 
     
     
         10 . The process according to any one of  claims 1 - 8 , wherein the keratin fiber has a tenacity of about 1 g/den to about 2 g/den. 
     
     
         11 . The process according to any one of  claims 1 - 10 , wherein the keratin fiber has a strain of at least about 5%. 
     
     
         12 . The process according to any one of  claims 1 - 10 , wherein the keratin fiber has a strain of about 5% to about 30%. 
     
     
         13 . The process according to any one of  claims 1 - 10 , wherein the keratin fiber has a strain of about 15%. 
     
     
         14 . The process according to  claim 13 , wherein the keratin fiber has been dried prior to measuring the strain. 
     
     
         15 . The process according to any one of  claims 1 - 14 , wherein the keratin fiber has a toughness higher than about 15 J/cm 3 . 
     
     
         16 . The process according to any one of  claims 1 - 15 , wherein the keratin solution has a consistency coefficient (K) of about 2 Pa·s n  to about 6 Pa·s n , wherein the keratin solution is at about 25° C. and comprises keratin at about 18% w/w of the composition. 
     
     
         17 . The process according to any one of  claims 1 - 16 , wherein the keratin solution has a consistency coefficient (K) of about 4.2 Pa·s n , wherein the keratin solution is at about 25° C. and comprises keratin at about 18% w/w of the composition. 
     
     
         18 . The process according to any one of  claims 1 - 17 , wherein the keratin solution has a flow behavior index of about 0.8 to about 0.95, wherein the keratin solution is at about 25° C. and comprises keratin at about 18% w/w of the composition. 
     
     
         19 . The process according to any one of  claims 1 - 18 , wherein the keratin solution has a flow behavior index of about 0.91, wherein the keratin solution is at about 25° C. and comprises keratin at about 18% w/w of the composition. 
     
     
         20 . The process according to any one of  claims 1 - 19 , wherein the keratin solution comprises a reducing agent. 
     
     
         21 . The process according to any one of  claims 1 - 20 , wherein the keratin solution comprises sodium dodecyl sulfate (SDS). 
     
     
         22 . The process according to any one of  claims 1 - 21 , wherein the keratin solution is prepared from a keratinous material. 
     
     
         23 . The process according to  claim 1 , further comprising preparing the keratin solution. 
     
     
         24 . The process according to  claim 23 , wherein preparing the keratin solution comprises:
 i. extracting keratin from a keratinous material to form extracted keratin; and   ii. dissolving the extracted keratin in an aqueous solution comprising a reducing agent to form the keratin solution.   
     
     
         25 . The process according to  claim 24 , wherein the aqueous solution further comprises SDS. 
     
     
         26 . The process according to any one of  claims 22 ,  24 , and  25 , wherein the keratinous material comprises one or more of: animal hair, horn, and feather including but not limited to wool, camel hair, alpacas hair and rabbit hair. 
     
     
         27 . The process according to  claim 26 , wherein the feather is a duck feather, a goose feather, a chicken feather, or a combination thereof. 
     
     
         28 . The process according to  claim 26 , wherein the hair is wool, camel hair, alpaca hair, rabbit hair, or a combination thereof. 
     
     
         29 . The process according to any one of  claims 23 - 28 , wherein the keratin fiber comprises at least 70% of the disulfide crosslinkages compared to the amount of disulfide crosslinkages in the keratinous material. 
     
     
         30 . The process according to any one of  claims 23 - 29 , wherein the keratin fiber comprises at least 85% of the beta-sheet crystallinity compared to the amount of beta-sheet crystallinity in the keratinous material. 
     
     
         31 . The process according to any one of  claims 18  and  24 - 30 , wherein the reducing agent comprises a thiol group. 
     
     
         32 . The process according to  claim 31 , wherein the reducing agent comprises mercaptoethanol, cysteine, dithiothreitol, 1,2-ethanedithiol, 1,3-benzenedithiol, bis(2-mercaptoethyl) ether, ethylene glycol bisthioglycolate, or a combination thereof. 
     
     
         33 . The process according to any one of  claims 1 - 32 , wherein the step of extruding a keratin solution into a first solution comprises using a spinneret to extrude the keratin solution. 
     
     
         34 . The process according to  claim 33 , wherein the spinneret comprises a hole, wherein the hole has a diameter of about 50 micrometers. 
     
     
         35 . The process according to any one of  claims 1 - 34 , wherein the first solution comprises an electrolyte. 
     
     
         36 . The process according to  claim 35 , wherein the electrolyte is a sulfate, an acetate, a chloride, a citrate, a carbonate, a phosphate, or a combination thereof. 
     
     
         37 . The process according to any one of  claims 1 - 36 , wherein the first solution comprises sodium sulfate, zinc sulfate, and acetate buffer. 
     
     
         38 . The process according to any one of  claims 1 - 37 , wherein the pH of the first solution is about 2. 
     
     
         39 . The process according to any one of  claims 1 - 38 , wherein the first solution comprises sodium sulfate in an amount of about 15% w/w of the composition, zinc sulfate in an amount of about 5% w/w of the composition, and acetate buffer with a pH of 2. 
     
     
         40 . The process according to any one of  claims 1 - 39 , wherein the step of oxidizing comprises exposing the fiber to an oxidizing solution comprising an oxidant selected from the group consisting of: a peroxide, a halogen oxoacid or salt thereof, a high-valent metal salt, and a combination thereof. 
     
     
         41 . The process according to  claim 40 , wherein the peroxide is an alkali metal peroxide, an alkaline earth metal peroxide, or a combination thereof. 
     
     
         42 . The process according to  claim 41 , wherein the oxidant is sodium periodate. 
     
     
         43 . The process according to any one of  claims 40 - 42 , wherein the oxidizing solution further comprises a buffer. 
     
     
         44 . The process according to any one of  claims 40 - 43 , wherein the oxidizing solution further comprises acetate buffer. 
     
     
         45 . The process according to any one of  claims 40 - 44 , wherein the pH of the oxidizing solution is about 2. 
     
     
         46 . The process according to any one of  claims 40 - 45 , wherein the temperature of the oxidizing solution is about 35° C. 
     
     
         47 . The process according to any one of  claims 1 - 46 , wherein the step of drawing the treated fiber and oxidizing the treated fiber is repeated two times. 
     
     
         48 . The process according to any one of  claims 1 - 47 , wherein the process further comprises drawing the treated fiber prior to setting the treated fiber. 
     
     
         49 . The process according to any one of  claims 1 - 48 , wherein setting the treated fiber comprises exposing the treated fiber to a wash solution comprising a surfactant. 
     
     
         50 . The process according to  claim 49 , wherein the surfactant is selected from the group consisting of: ammonium lauryl sulfate, SDS, sodium laureth sulfate, sodium myreth sulfate, sodium stearate, sodium lauroyl sarcosinate, perfluorononanoate, perfluorooctanoate, (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate), cocamidopropyl hydroxysultaine, cocamidopropyl betaine, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, a sphingomyelin, cetrimonium bromide (CTAB), cetylpyridinium chloride (CPC), benzalkonium chloride (BAC), benzethonium chloride (BZT), dimethyldioctadecylammonium chloride, dioctadecyldimethylammonium bromide (DODAB), and a combination thereof. 
     
     
         51 . The process according to  claim 49  or  50 , wherein the wash solution further comprises an acetate buffer. 
     
     
         52 . The process according to any one of  claims 49 - 51 , wherein the wash solution has a pH of about 2. 
     
     
         53 . The process according to any one of  claims 49 - 52 , wherein the wash solution is at a temperature of about 40° C. 
     
     
         54 . The process according to any one of  claims 1 - 53 , wherein setting the treated fiber comprises winding the treated fiber and oxidizing the treated fiber. 
     
     
         55 . The process according to  claim 54 , wherein exposing the treated fiber to a wash solution comprising a surfactant is performed prior to winding the treated fiber and oxidizing the treated fiber. 
     
     
         56 . The process according to any one of  claims 1 - 55 , wherein winding the treated fiber is at a rate of about 15 meters/minute. 
     
     
         57 . The process according to any one of  claims 1 - 56 , wherein the keratin fiber is dried at about 85° C. for about 1 hour. 
     
     
         58 . The process according to any one of  claims 1 - 57 , wherein the keratin fiber is annealed at about 125° C. for about 1 hour. 
     
     
         59 . The process according to  claim 58 , wherein the keratin fiber is annealed after it is dried. 
     
     
         60 . The process according to any one of  claims 1 - 59 , wherein the process is a continuous process. 
     
     
         61 . The process according to any one of  claim 1 - 60 , wherein the process further comprises exposing the keratin fiber to a solution comprising an oxidized saccharide. 
     
     
         62 . The process according to  claim 61 , wherein the keratin fiber is exposed to the solution comprising an oxidized saccharide for about 3 to about 25 hours. 
     
     
         63 . The process according to  claim 61  or  62 , wherein the oxidized saccharide is a sucrose polyaldehyde. 
     
     
         64 . The process according to any one of  claims 61 - 63 , wherein the step of exposing the keratin fiber to a solution comprising an oxidized saccharide is performed prior to exposing the treated fiber to a wash solution comprising a surfactant. 
     
     
         65 . A keratin fiber prepared by the process of any of one  claims 1 - 64 .