CN101519812A

CN101519812A - Process for manufacturing oxidized cellulose regenerated fibrils or thin films

Info

Publication number: CN101519812A
Application number: CN200810054566A
Authority: CN
Inventors: 李换位
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-25
Filing date: 2008-02-25
Publication date: 2009-09-02

Abstract

A process for manufacturing oxidized cellulose regenerated fibrils or thin films comprises the steps of: immersing refined pulp cellulose or degreased cotton cellulose in dilute acid (or hydrochloric acid or sulfuric acid or nitric acid) water solution, crushing to lead the cellulose to be loose, then placing the cellulose in circulating air with the temperature of 35-65 DEG C and the humidity of 85-97 percent for a period of time or placing the cellulose in the naturally circulating air above 25 DEG C for keeping in shade for a period of time by diurnal cycle till the cellulose thereof is very easy to be powdered and can be rapidly dissolved in dilute caustic soda water solution, preparing the powdered oxidized cellulose by water washing, drying and crushing, then dispersing and dissolving the powdered oxidized cellulose in the dilute caustic soda water solution to prepare viscous spinnable solution, solidifying and regenerating the oxidized cellulose in the dilute acid water solution or water-containing ethanol solution through a spinning head or a narrow slit, and preparing the oxidized cellulose regenerated fibrils or the thin films by acid pickling, washing and drying the regenerated fibrils or thin films.

Description

Oxidized cellulose regenerated fibrils or thin film fabrication technology

Technical field

This technology relates to refined pulp cellulose or the plain aerial autoxidation of degreasing cotton fiber, the manufacturing of preparation oxycellulose and oxidized cellulose regenerated fibrils or film.

Background technology

Cellulose is a macromolecule the abundantest on the earth, by to the esterification of hydroxyl on the cellulosic molecule, nitrated, etherificate and oxidation, can prepare the cellulose derivative with various performances.And have only oxidation that cellulose degradable in human body is absorbed.Cellulosic mild oxidation product is made up of oxidized portion and unreacted residue.Oxidizing condition acutely can aggravate cellulosic degraded, and the intoxicated ring of breaking part glucose makes the forfeiture of cellulose primary structure feature.Because cotton fiber is tapered, physicochemical property is inhomogeneous, and is repeatable poor.And the regenerated cellulose fibril is well-balanced, and evenly oxidation obtains the uniform oxidation product of physicochemical property.Although metaperiodic acid salt, hypochlorite and bichromate all can be used as the cellulose oxidation agent, and have only employing NO ₂The oxycellulose carboxyl-content height that oxidation makes, physical property is good, NO ₂Oxidation can be carried out in gas phase and liquid phase.(1) gaseous oxidation: the NO that adopts gaseous state ₂Oxycellulose, reaction temperature are 25 ℃, and its advantage is that cost is low, is easy to remove remaining NO ₂, shortcoming is the device complexity, requires oxidation unit can carry out gas circulation, removes reaction heat.After finishing, reaction washes oxidation product with water.(2) liquid oxidatively: with NO ₂Introduce in its atent solvent, generate 20% solution, fiber is evenly oxidation in solution, and reaction temperature is 25 ℃.(3) oxidation mechanism: gas phase or liquid phase NO ₂The process of oxycellulose mainly is that the C-6 hydroxyl on the intoxicated unit of glucose is changed into carboxyl, and its mechanism may be NO ₂Form cellulose nitrite intermediate with cellulose earlier, participate in oxidation subsequently, the catabolite behind this oxycellulose implant into body is glucuronic acid and glucose, can be by organism metabolism and absorption.

Cellulose oxidation becomes carboxyl-content up to 10% (mass fraction) when above, and this oxycellulose promptly has biodegradation and absorbability.The speed of bio-absorbable becomes big with the increase of degree of oxidation.When carboxyl-content is 12%--24% (mass fraction), oxycellulose can be absorbed fully by body in one month, infiltration rate and tissue reactive also are subjected to the influence of some factors, and they comprise volume, shape, wound size and the infection etc. of implant.

Oxycellulose is because pH value low (2-4) has antibacterial activity to many pathogens, and oxycellulose is widely used as medical science operation styptic or the agent of wound adhesion barrier.Carboxyl on the oxycellulose can be connected by absorption, absorption, ionic bonding or peptide bond with many chemical constituents.(medicinal biodegradation macromolecular material/Guo Shengrong chief editor---Beijing: Chemical Industry Press 2003,11, natural semisynthetic Biodegradable polymer---oxycellulose)

Existing to make with extra care (through acid, alkali treatment) pulp is the rayon spinning formulations prepared from solutions and the spinning technique of raw material, its technical process is: refined pulp is inserted watering in the aqueous slkali of 10%--20%, at 25 ℃--45 ℃ flood down, make cellulose and NaOH effect generate alkali cellulose, again through squeezing, remove its unnecessary alkali lye and the hemicellulose that dissolves in, then the alkali cellulose of squeezing is pulverized, and make it under 18 ℃ or 60 ℃ of constant temperatures, keep certain hour, (being the maturation of alkali cellulose), then, through the alkali cellulose of maturation under the temperature controlled condition of strictness with CS ₂Reaction makes it generate cellulose xanthate (being the yellow of alkali cellulose), CS during yellow ₂Addition be generally the 30%--35% of alkali cellulose, then the cellulose xanthate dispersing and dissolving is formed viscose solution in dilute alkaline soln, the composition of this viscose solution generally be chemical cellulose content at 6%--8.5%, the content of NaOH is at 4%--7%.This viscose solution also needs to carry out the esterification degree of special maturation (hydrolysis of cellulose xanthate) with the plain xanthate acid of controlling fiber under the condition of control temperature, and then filter, deaeration is to obtain the viscose solution that range of viscosities has good spinnability at 40-200S (falling ball viscosity).This spinnability viscose solution in the coagulating bath of forming by sulfuric acid, sodium sulphate or zinc sulfate, spray silk wet spinning or diluted acid bathe in plasticity draw stretch regeneration after, the viscose glue strand is through washing, desulfurization bleaching, is washed, is oiled, after the drying, promptly obtains the plant cellulose regenerated viscose fiber at pickling.

Obviously, this technology need experience the strict chemical reaction process of controlling of complicated tediously long multistage, consume a large amount of industrial chemicals, as refined pulp, carbon disulfide, caustic soda, sulfuric acid, sodium sulphate, zinc sulfate finish etc., one ton of viscose of the every production of above-mentioned technical process usually need be with 3-3.5 tons of industrial chemicals, except that pulp fibers element or part finish enter the product, remaining industrial chemicals finally all discharges with three wastes form.Wherein nearly 150 cubic meter of gas of one ton of product of the every production of waste gas discharge, and the sulfide that wherein contains in each cubic metre waste gas about 1kg mainly is H ₂S, CS ₂With a spot of SO ₂Or furfurylmercaptan etc., these gases are all toxic to human body, and the intensive property pungent odor is arranged.Wherein one ton of product of the every production of waste water need discharge 500-1200 tons of waste water usually, comprise alkaline waste water, acid waste water and middle wastewater, contain in these waste water and be corrosive and toxicant, the harmfulness maximum of zinc wherein, though these unfavorable factors can be solved by setting up perfect recovery system, its equipment investment and and the costliness of operating cost, on certain Cheng Du, still restricting the development of adhering process.(Wu Guoming chief editor: processing of high molecular material technology, Beijing: China Textiles Press's 2007.7 viscoses and novel solvent method cellulose fibre 192-321).

Summary of the invention

The technological problems that the present invention need solve is: the plain aerial autoxidation of refined pulp cellulose and degreasing cotton fiber, obtain cheap oxycellulose, and oxycellulose spinnable solution preparation or its oxycellulose fibril and form of film solidify regeneration in its coagulating bath.Its technical process is: with refined pulp cellulose or degreasing cotton fiber element, insert the inorganic acid that concentration is 2.5%--5.5% (perhaps hydrochloric acid, perhaps sulfuric acid, perhaps nitric acid) in the aqueous solution, after evenly flooding, again after squeezing and making it loose, being placed on temperature is 35 ℃--65 ℃, humidity is certain hour in the ventilating air of 85%--97%, perhaps place it in more than 25 ℃ in the spontaneous current blowing air, through day-night cycle the moon certain hour that dries in the air, utilize the air oxygen autoxidation, be easy to powdered and when dispersing and dissolving was in rare caustic-soda aqueous solution rapidly, its cellulose had changed into oxycellulose until pulp fibers element or degreasing cotton fiber element.After washing this oxycellulose to washings with water and being neutrality, dryly also grind this oxycellulose, just make the powdered oxycellulose.The powdered oxycellulose dispersing and dissolving that makes in the 4%--16% caustic-soda aqueous solution, make range of viscosities at 40-220s (falling ball viscosity) can spunbond property solution.Again this spinnable solution by spinning head or long and narrow seam road or directly wet spinning or through dry-jet wet-spinning, make it enter into the dilute sulfuric acid aqueous solution that is dissolved with sodium sulphate, perhaps enter into hydrous ethanol organic solution, solidify again born with oxycellulose fibril or filminess.This regenerated fibrils or film just make oxidized cellulose regenerated fibrils or regeneration film after pickling, washing, drying.

Be not difficult to find out that from above technical process initiation material of the present invention is that refined pulp or absorbent cotton and existing rayon spinning technology are raw materials used basic identical, and has totally saved an existing rayon spinning technical process cost than existing oxycellulose preparation technology.The present invention is flooded with diluted acid, dipping process does not have the stripping of raw cellulose, acid solution through squeezing out can be recycled, thereby without any significant loss, and be again to be oxidant with the natural air, it is the most green cheap oxidation, the oxycellulose of the present invention's acquisition is cheap more a lot of than the oxycellulose of existing prepared obviously, be again that only this can obtain cellulosic spinnable solution once the step, solvent for use is rare soda bath equally, but saved out the alkali cellulose yellow technical process cost of existing technical process than existing technology, and can make cellulosic regeneration spinning technique become cheap and cleaning thus, yet the more important thing is that technology of the present invention not only can prepare the powdered oxycellulose that is dirt cheap; And regenerated fibrils or film, and can expand the Application Areas or the scope of cellulose regenerated fibrils or film.

The specific embodiment

It is 2.5%--5.5% inorganic acid (perhaps hydrochloric acid that refined pulp or degreasing cotton fiber element are inserted concentration respectively, perhaps sulfuric acid, perhaps nitric acid) in the aqueous solution, evenly behind the dipping, again after squeezing and making it loose, being placed on temperature respectively is 35 ℃--65 ℃, humidity is certain hour in the ventilating air of 85%--97%, perhaps be placed on temperature respectively more than 25 ℃ in the spontaneous current blowing air, through day-night cycle the moon certain hour that dries in the air, utilize the air oxygen autoxidation to be easy to powdered and when dispersing and dissolving is in rare caustic-soda aqueous solution rapidly until pulp fibers element or degreasing cotton fiber element, be washed with water to respectively after washings are neutrality, drying grinds respectively, just makes the powdered oxycellulose of refined pulp or absorbent cotton respectively.The powdered oxycellulose that makes respectively through dispersing and dissolving in the 4%--16% caustic-soda aqueous solution, make range of viscosities behind the viscosity solution of 40-220s (falling ball viscosity), respectively after filtration or after deaeration filters, make the oxycellulose viscosity solution with fibril or filminess through spinning head or long and narrow seam road respectively, or directly enter or to be that dilute sulfuric acid aqueous solution that 23--55 ℃ of concentration is 4%--6% solidifies again born by entering into the temperature that is dissolved with sodium sulphate behind the 3-10mm air layer, perhaps entering into temperature is that 23--55 ℃ of hydrous ethanol organic solution is solidified born again.Regenerated fibrils or film are 25--55 ℃ through temperature respectively, and concentration again through synthermal washing, drying, can obtain oxidized cellulose regenerated fibrils or film after being the dilute sulfuric acid aqueous solution washing of 4%--7%.

Claims

1, oxidized cellulose regenerated fibrils or thin film fabrication technology, it is characterized in that: refined pulp or degreasing cotton fiber element are 2.5%--5.5% inorganic acid (perhaps hydrochloric acid through concentration, perhaps sulfuric acid, perhaps nitric acid) in the aqueous solution evenly behind the dipping, through squeezing and making it loose, then it being placed on temperature is 35 ℃--65 ℃, humidity is certain hour in the ventilating air of 85%--97%, perhaps be placed on temperature more than 25 ℃ in the spontaneous current blowing air, through day-night cycle the moon certain hour that dries in the air, utilize the air oxygen autoxidation to be easy to powdered and when dispersing and dissolving is in rare caustic-soda aqueous solution rapidly until pulp fibers element or degreasing cotton fiber element, its pulp fibers element or degreasing cotton fiber element have changed into oxycellulose, after washing this oxycellulose to washings then with water and being neutrality, carry out drying again, grind, just can obtain this powdered oxycellulose.The powdered oxycellulose that obtains through dispersing and dissolving in the 4%--16% caustic-soda aqueous solution, make range of viscosities behind the viscosity spinnable solution of 40-220s (falling ball viscosity), by spinning head or long and narrow seam road, make the oxycellulose viscosity solution with fibril or filminess, or through wet spinning or through dry-jet wet-spinning (behind the 3-10mm air layer), or to enter into the temperature that is dissolved with sodium sulphate be that the dilute sulfuric acid aqueous solution that 23--55 ℃ of concentration is 4%--6% solidifies regeneration, and perhaps entering into temperature is that 23--55 ℃ of hydrous ethanol organic solution is solidified born again.This regenerated fibrils or film are 25--55 ℃ through temperature, after concentration is the dilute sulfuric acid aqueous solution washing of 4%--7%, again through synthermal washing, drying, can obtain oxidized cellulose regenerated fibrils or film by refined pulp cellulose or the plain preparation of degreasing cotton fiber.