Fibers for producing composite materials and methods of producing carbon fiber precursor fibers and carbon fibers

Abstract

A method for producing carbon-containing fibers, in particular carbon fibers and/or the precursor fibers thereof, contains the following steps: a) providing one or more starting material fibers; b) bringing the one or more starting material fibers in contact with at least one treatment fluid, wherein a treatment fluid has at least one silicon compound and has a content of 0-25 wt. % water, in relation to the total weight of the treatment fluid; c) treating the one or more starting material fibers with the treatment fluid during a treatment time having a duration of at least three minutes at a treatment temperature ranging from 126 C to 450 C.

1 . A method for producing carbon-containing fibers, which comprises the steps of:
 providing at least one starting material fiber;   bringing the at least one starting material fiber in contact with at least one treatment fluid having at least one silicon compound and a content of 0-25 wt. % of water, relative to a total weight of the treatment fluid; and   treating the at least one starting material fiber with the treatment fluid during a treatment time interval having a duration of at least three minutes at a treatment temperature in a range of 126° C. to 450° C. resulting in treated fibers.   
     
     
         2 . The method according to  claim 1 , which further comprises carrying out a further temperature treatment on at least one of the treated fibers, after-treated fibers or dried fibers, wherein the fibers are exposed to a temperature of at least 450° C. in an inert atmosphere during a further temperature treatment time interval. 
     
     
         3 . The method according to  claim 1 , wherein the at least one starting material fiber contains fibers selected from the group consisting of polyacrylonitrile-based fibers, polyacetylene-based fibers, polyphenylene-based fibers, cellulose-based fibers, pitch-based fibers, lignin-based fibers, viscose-based fibers, polypropylene-based fibers, mixtures of carbon-containing fibers and ceramic-based fibers, and mixtures thereof. 
     
     
         4 . The method according to  claim 1 , wherein the treatment temperature lies in a range of 136° C. to 360° C. 
     
     
         5 . The method according to  claim 1 , which further comprises performing the treating step at a first temperature range and at least one second temperature range, wherein a lowest temperature of the at least one second temperature range is higher than a highest temperature of the first temperature range and the treating step begins with a treatment of the at least one starting material fiber in the first temperature range. 
     
     
         6 . The method according to  claim 5 , which further comprises:
 setting the first temperature range to be 126° C. to 260° C.; and   setting the at least one second temperature range to be 140° C. to 450° C.   
     
     
         7 . The method according to  claim 1 , wherein a temperature of the treatment fluid increases one of continuously or discontinuously during the treatment time interval entirely or at least one time segments of the treatment time interval. 
     
     
         8 . The method according to  claim 1 , wherein the treatment time interval includes at least one time segment during which a temperature is kept constant or substantially constant at one temperature and includes at least one time segment during which the temperature is varied. 
     
     
         9 . The method according to  claim 1 , wherein a temperature of the treatment fluid is one of increased or decreased at least during one time segment of the treatment time interval by 0.5 to 15° C./minute. 
     
     
         10 . The method according to  claim 1 , wherein the treatment fluid comprises at least one silicon compound selected from the group consisting of polydialkyl siloxanes, polydiaryl siloxanes and polymonoalkylmonoaryl siloxanes. 
     
     
         11 . The method according to  claim 1 , wherein the treatment fluid has a water content of 0.001-22 wt. % relative to the total weight of the treatment fluid. 
     
     
         12 . The method according to  claim 1 , which further comprises providing the at least one starting material fiber before and/or at least partly during the treating step in a clamped state. 
     
     
         13 . The method according to  claim 1 , which further comprises:
 subjecting the treated fibers to at least one mechanical after-treatment process, the mechanical after-treatment process being at least one of a pressing process, an extraction process, a dropping process or a washing process having an extraction and/or a treatment in a bath under an action of ultrasound.   
     
     
         14 . The method according to  claim 2 , wherein the at least one starting material fiber after the treating step and before the further temperature treatment step does not come in contact with an atmosphere having a content of more than 5 wt. % of oxygen and a temperature of 70° C. or more. 
     
     
         15 - 25 . (canceled) 
     
     
         26 . A carbon fiber precursor fiber, comprising:
 a fiber having a surface and a carbon content of 49.9 wt. % to 63.5 wt. % relative to a total weight of the carbon fiber precursor fiber; and   silicon-containing deposits disposed on said surface of said fiber.   
     
     
         27 . The carbon fiber precursor fiber according to  claim 26 , wherein the carbon fiber precursor fiber has a density of 1.30-1.50 g/cm 3 . 
     
     
         28 . The carbon fiber precursor fiber according to  claim 26 , wherein said fiber has at least one of a silicon content of at least 19 wt. %, a nitrogen content of 3.3 wt. % to 16.2 wt. %, or an oxygen content of 12.4 wt. % to 14.0 wt. %, in each case relative to a total weight of the carbon fiber precursor fiber. 
     
     
         29 . (canceled) 
     
     
         30 . A method of producing a carbon fiber precursor fiber having a surface, a carbon content of 49.9 wt. % to 63.5 wt. % relative to a total weight of the carbon fiber precursor fiber, and silicon-containing deposits on the surface, which comprises the steps of:
 a) providing at least one starting material fiber;   b) bringing the at least one starting material fiber in contact with at least one treatment fluid, wherein the treatment fluid contains at least one silicon compound and has a content of 0-25 wt. % of water, relative to a total weight of the treatment fluid; and   c) treating the at least one starting material fiber with the treatment fluid during a treatment time interval having a duration of at least three minutes at a treatment temperature in a range of 126° C. to 450° C. resulting in a treated fiber.   
     
     
         31 . The method according to  claim 30 , which further comprises:
 d) after-treating the treated fiber with at least one mechanical after-treatment process and no washing process takes place between step c) and step e) resulting in an after-treated fiber; and   e) drying the after-treated fiber.   
     
     
         32 . A carbon fiber precursor fiber, comprising:
 a fiber having a surface and a carbon content of 52.9 wt. % to 81.6 wt. % relative to a total weight of the carbon fiber precursor fiber; and   silicon-containing deposits disposed on said surface of said fiber.   
     
     
         33 . The carbon fiber precursor fiber according to  claim 32 , wherein the carbon fiber precursor fiber which has a density which is more than 1.20 g/cm 3 . 
     
     
         34 . (canceled) 
     
     
         35 . The carbon fiber precursor fiber according to  claim 32 , wherein said fiber has at least one of a silicon content of at least 0.5 wt. %, a nitrogen content of 7.3 wt. % to 34.4 wt. %, or an oxygen content of 3.3 wt. % to 9.7 wt. %., in each case relative to the total weight of the carbon fiber precursor fiber. 
     
     
         36 . (canceled) 
     
     
         37 . A method of producing a carbon fiber precursor fiber having a surface, a carbon content of 52.9 wt. % to 81.6 wt. % relative to a total weight of the carbon fiber precursor fiber, and silicon-containing deposits disposed on the surface, which comprises the steps of:
 a) providing at least one starting material fiber;   b) bringing the at least one starting material fiber in contact with at least one treatment fluid, wherein the treatment fluid contains at least one silicon compound and has a content of 0-25 wt. % of water, relative to a total weight of the treatment fluid; and   c) treating the at least one starting material fiber with the treatment fluid during a treatment time interval having a duration of at least three minutes at a treatment temperature in a range of 126° C. to 450° C. resulting in treated fibers.   
     
     
         38 . The method according to  claim 37 , which further comprises:
 d) after-treating the treated fibers by at least one of at least one washing process or by at least one mechanical after-treatment processes resulting in after treated fibers; and   e) drying the after-treated fibers.   
     
     
         39 . A carbon fiber, comprising:
 a fiber having a surface and a carbon content of 94.0 wt. % to 94.6 wt. % relative to a total weight of the carbon fiber; and   silicon-containing deposits disposed on said surface of said fiber.   
     
     
         40 . The carbon fiber according to  claim 39 , wherein the carbon fiber has a density which is more than 1.20 g/cm 3 . 
     
     
         41 . (canceled) 
     
     
         42 . The carbon fiber according to  claim 39 , wherein said fiber has at least one of a silicon content in a range of more than 0.45 wt. %, a nitrogen content of 2.4 wt. % to 2.9 wt. %, or an oxygen content of 2.6 wt. % to 2.7 wt. %., in each case relative to the total weight of the carbon fiber. 
     
     
         43 . (canceled) 
     
     
         44 . A method of making a carbon fiber having a surface, a carbon content of 94.0 wt. % to 94.6 wt. % relative to a total weight of the carbon fiber, and silicon-containing deposits on the surface, which comprises the steps of:
 a) providing at least one starting material fiber;   b) bringing the at least one starting material fiber in contact with at least one treatment fluid, wherein the treatment fluid contains at least one silicon compound and having a content of 0-25 wt. % of water, relative to a total weight of the treatment fluid;   c) treating the at least one starting material fiber with the treatment fluid during a treatment time interval having a duration of at least three minutes at a treatment temperature in a range of 126° C. to 450° C. resulting in treated fibers; and   d) after-treating the treated fibers by at least one washing process resulting in after-treated fibers.   
     
     
         45 . The method according to  claim 44 , which further comprises:
 e) performing at least one mechanical after-treatment process on the after-treated fibers;   f) drying the after-treated fibers resulting in dried fibers; and   g) carrying out a further temperature treatment on the dried fibers, wherein the dried fibers are exposed to a temperature of at least 450° C. in an inert atmosphere during a temperature treatment time interval.   
     
     
         46 . A carbon fiber, comprising:
 a fiber having a surface and a carbon content of 94.0 wt. % to 94.6 wt. % relative to a total weight of the carbon fiber; and   silicon-containing deposits disposed on said surface of said fibers.   
     
     
         47 . The carbon fiber according to  claim 46 , wherein the carbon fiber has a density which is greater than 1.20 g/cm 3 . 
     
     
         48 . (canceled) 
     
     
         49 . The carbon fiber according to  claim 46 , wherein said fiber has at least one of a silicon content in a range of more than 0.45 wt. %, a nitrogen content of 2.4 wt. % to 2.9 wt. %, or an oxygen content of 1.5 wt. % to 2.1 wt. %, in each case relative to the total weight of the carbon fiber. 
     
     
         50 . (canceled) 
     
     
         51 . A method of making a carbon fiber having a surface, a carbon content of 94.0 wt. % to 94.6 wt. % relative to a total weight of the carbon fiber, and silicon-containing deposits disposed on the surface, which comprises the steps of:
 a) providing at least one starting material fiber;   b) bringing the at least one starting material fiber in contact with at least one treatment fluid, wherein the treatment fluid contains at least one silicon compound and having a content of 0-25 wt. % of water, relative to a total weight of the treatment fluid; and   c) treating the at least one starting material fiber with the treatment fluid during a treatment time interval having a duration of at least three minutes at a treatment temperature in a range of 126° C. to 450° C. resulting in treated fibers.   
     
     
         52 . The method according to  claim 51 , which further comprises:
 d) after-treating the treated fibers with at least one mechanical after-treatment process and no washing process takes place between the step c) and step f) resulting in after-treated fibers;   e) drying the after-treated fibers resulting in dried fibers; and   f) carrying out a temperature treatment of the dried fibers, wherein the dried fibers are exposed to a temperature of at least 450° C. in an inert atmosphere during a temperature treatment time interval.   
     
     
         53 . The carbon fiber precursor fiber according to  claim 26 , wherein said silicon-containing deposits contain particle-like deposits having a greatest length extension of less than 40 μm. 
     
     
         54 - 58 . (canceled) 
     
     
         59 . The carbon fiber according to  claim 39 , wherein said silicon-containing deposits contain particle-like deposits having a greatest length extension of less than 40 μm. 
     
     
         60 - 64 . (canceled) 
     
     
         65 . A method of using the carbon fiber precursor fiber according to  claim 26 , which comprises the steps of:
 producing an item selected from the group consisting of a woven fabric, a fiber scrim, a composite material, and a C/SiC composite material from the carbon fiber precursor fiber.   
     
     
         66 . A method of using the carbon fiber precursor fiber according to  claim 32 , which comprises the steps of:
 producing an item selected from the group consisting of a woven fabric, a fiber scrim, a composite material, and a C/SiC composite material from the carbon fiber precursor fiber.   
     
     
         67 . A method of using the carbon fiber according to  claim 39 , which comprises the steps of:
 producing an item selected from the group consisting of a woven fabric, a fiber scrim, a composite material, and a C/SiC composite material from the carbon fiber.   
     
     
         68 . A method of using the carbon fiber according to  claim 46 , which comprises the steps of:
 producing an item selected from the group consisting of a woven fabric, a fiber scrim, a composite material, and a C/SiC composite material from the carbon fiber.