Raw cotton linters composition, method of making, and uses thereof
View Patent ↗A composition of a loose mass of comminuted raw cotton linter fibers has a bulk density of at least 8 g/100 ml and at least 50% of the fibers in the mass passes through a US standard sieve size #10 (2 mm opening). This composition is made by obtaining a loose mass of first cut, second cut, third cut, or mill runs raw cotton linters or mixtures thereof and comminuting the loose mass of raw cotton linters to a size wherein at least 50% pass through a US standard sieve size #10 (2 mm opening). This composition is used to make cellulose ether derivatives.
1. A process for making a cellulose ether derivative comprising
a) mixing a composition comprising a loose mass of raw cut cotton linter fibers that
i) has a bulk density of at least 20 g/100 ml and
ii) at least 50 wt % of the fibers in the loose mass passes through a US standard sieve size #10 (2 mm opening) as a starting material with a base to form an activated cellulose mixture and,
b) reacting the activated cellulose mixture with at least one etherifying agent to form a cellulose ether derivative product containing a cellulose ether derivative, wherein mixing power of the activated cellulose mixture is 5% lower than the mixing power of the same process using comparably comminuted purified celluloses, wherein the cutting is carried out in a rotary cutter, wherein the upper limit of cellulose content in the fibers in the cut mass of raw cotton linters is 95 wt %, wherein the molecular weight of the raw cut cotton linter fibers as determined by intrinsic viscosity (IV) has not been reduced by more than 20% relative to non-comminuted raw cotton linters, wherein the loose mass of raw cut cotton linter fibers have a number average length range of 253-541.
2. The process of claim 1 , wherein the mixing power of the activated cellulose mixture is 10% lower than the mixing power of the same process using comparably comminuted purified celluloses.
3. The process of claim 1 , wherein the mixing power of the activated cellulose mixture is 15% lower than the mixing power of the same process using comparably comminuted purified celluloses.
4. The process of claim 1 , wherein the base is selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, ammonium hydroxide, lithium hydroxide, strong organic bases and mixtures thereof.
5. Process of claim 1 wherein the base is selected from the group consisting of amines, quaternary ammonium hydroxides, and mixtures thereof.
6. The process of claim 1 , wherein the etherifying agent is selected from the group consisting of alkyl halides, alkenyl halides, alkylene oxides, glycidyl ethers, metal salts of alpha-halogenoalkanoates, vinyl sulfonates, and mixtures thereof.
7. The process of claim 1 , wherein the etherifying agent is selected from the group consisting of methyl chloride, ethyl chloride, ethylene oxide, propylene oxide, butylene oxide, monochloroacetic acid and salts thereof, butyl glycidyl ether, and glycidyl silane.
8. The process of claim 1 , wherein the cellulose ether derivative is selected from the group consisting of carboxymethylcellulose (CMC), hydrophobically modified carboxymethylcellulose (HMCMC), methylcellulose (MC), ethylcellulose (EC), hydroxyethylcellulose (HEC), carboxymethylhydroxyethylcellulose (CMHEC), carboxymethyl hydrophobically modified hydroxyethylcellulose (CMHMHEC), hydrophobically-modified hydroxyethylcellulose (HMHEC), methylhydroxyethylcellulose (MHEC), methylhydroxypropylcellulose (MHPC), ethylhydroxyethylcellulose (EHEC), hydrophobically-modified ethyhydroxyethylcellulose, (HMEHEC), methylethylhydroxyethylcellulose (MEHEC), hydroxypropylcellulose (HPC), and hydrophobically-modified hydroxypropylcellulose (HMHPC).
9. The process of claim 8 , wherein the cellulose ether derivative is carboxymethylcellulose having a degree of substitution of 0.1 to 2.5.
10. The process of claim 1 , wherein cellulose ether derivative product is further processed to increase its purity.
11. The process of claim 10 , wherein the further processing comprises extracting nonpolymeric salts from the cellulose ether derivative product through the use of liquid media in which the cellulose ether derivative is rendered substantially insoluble.
12. The process of claim 1 , wherein the starting material or the cellulose ether derivative product is further processed with a viscosity reducing agent to lower the intrinsic viscosity of the cellulose ether product.
13. The process of claim 12 , wherein the viscosity reducing agent is performed by chemical means.
14. The process of claim 12 , wherein the viscosity reducing agent is performed by mechanical means.
15. The process of claim 12 , wherein the viscosity reducing agent is performed by irradiation.
16. The process of claim 12 , wherein the viscosity reducing ac en performed by enzymatic means.
17. The process of claim 1 , wherein the cellulose ether derivative product contains at least 65% of the cellulose ether derivative.
18. The process of claim 1 , wherein the cellulose ether derivative product contains at least 75% of the cellulose ether derivative.
19. The process of claim 1 , wherein the cellulose ether derivative product contains at least 95% of the cellulose ether derivative.
20. The process of claim 1 wherein the starting material is dispersed in a nonreactive organic diluent.
21. The process of claim 20 wherein the nonreactive organic diluent is selected from the group consisting of acetone, methanol, ethanol, isopropanol, t-butyl alcohol, and mixtures thereof.
22. The process claim 21 wherein the nonreactive organic diluent contains water.
23. The process of claim 1 , wherein the bulk density of the loose mass of raw cut cotton linter fibers has an upper limit of 75 g/100 ml.
24. The process of claim 1 , wherein the bulk density of the loose mass of raw cut cotton linter fibers has an upper limit of 60 g/100 ml.
25. The process of claim 1 , wherein the bulk density of the loose mass of raw cut cotton linter fibers has an upper limit of 50 g/100 ml.