CN103562277A

CN103562277A - Process for processing cellulose films or shaped articles

Info

Publication number: CN103562277A
Application number: CN201280024609.1A
Authority: CN
Inventors: 马丁·理查德·科克罗夫特; 卢克·费希尔
Original assignee: Innovia Films Ltd
Current assignee: Innovia Films Ltd
Priority date: 2011-05-20
Filing date: 2012-05-18
Publication date: 2014-02-05
Also published as: WO2012160362A1; JP6022554B2; JP2014517109A; EP2710054A1

Abstract

The present invention provides a process for producing cellulose film or cellulose shaped articles comprising the steps of steeping a non-dissolving cellulose- containing pulp in a basic liquid, xanthating the steeped cellulose-containing pulp with carbon disulphide, dissolving the xanthated cellulose-containing pulp in a basic liquid to form a viscose solution, and casting a cellulose film or cellulose shaped article from the viscose solution, wherein one or more of the following optimised processing conditions are employed: steeping is carried out, at least partially, at a temperature of about 30 DEG C to about 50 DEG C, steeping is carried out in a basic liquid having a concentration of base of about 16 to about 18% by weight, xanthation is carried out using about 30 to about 40% carbon disulphide by weight of cellulose present, xanthation is carried out, at least partially, at a temperature of about 20 DEG C to about 30 DEG C, dissolution is carried out, at least partially, at a temperature of about 10 DEG C to about 25 DEG C, dissolution results in a viscose solution having a base concentration of between about 5.5 and 7,5% by weight of the solution, and / or dissolution results in a viscose solution having a cellulose concentration of between about 8.5 and about 9.5% by weight of the solution.

Description

Method for processing of cellulose film or molded article

Invention field

The invention provides the optimization method of processing of cellulose, wherein the paper pulp of non-solubility cellulose is used for for the preparation of cellulose membrane or such as the viscose solution of the preparation of the cellulose forming product of fiber.

Background technology

Except the practicality in the industrial production of paper, the paper pulp of cellulose has a lot of other application, comprises cellulose membrane and such as the industry manufacture of the cellulose forming product of fiber.

The source that has the paper pulp of many cellulose, for example timber (particularly soft wood), cotton, flax, hemp and bamboo class.Paper pulp is prepared by these starting material conventionally, and described starting material also remove delignification and hemicellulose by processing with separation, thereby the content of cellulose of paper pulp is maximized.

Those skilled in the art are known two kinds of general pulping techniques.First, by grind or the starting material of milling with physically separated fiber cellulose fiber and hemicellulose and xylogen, can mechanically prepare paper pulp.

Alternatively, can chemically process starting material with dissolved lignin and hemicellulose, ideally not destroy and be derived from raw-material cellulosic fibre.The example of chemical pulping method comprises sulphate cook method (Kraft process) and sulphite process.

Also have a large amount of mixed pulp methods, wherein in mechanical pulp-making method, use chemical process step, vice versa.The example of such method comprises thermomechanical method, and wherein, except mechanical disintegration, wood chip or other starting material also will be exposed to heat; With chemi thermo mechanical method, wherein, before pulverizing and heat exposure, first wood chip is exposed to chemicals used in chemical pulping method.

For the technician in cellulose regenerated field, two class paper pulp from chemical pulping method, have been obtained.First-selection is ' dissolving pulp ' or ' dissolving grade paper pulp ', and it is as the raw material of viscose process.Dissolving pulp is characterised in that high cellulose content, approximately more than 90%.As shown in their title, they are soluble in commercial fibres element reclaiming process solvent used or jelly (dopes).

The another kind of of paper pulp is ' non-dissolving pulp ', and the example comprises ' commercial pulp ' or ' fluff pulp '.These have limited practicality in viscose process or other methods for the production of cellulose membrane or cellulose forming product, because as shown in their titles, they are insoluble in conventional process solutions or jelly.Therefore, they are mainly used in the application except cellulose regenerated.For example, in all fluff pulps, surpass 80% for the production of baby diaper.

Compare with dissolving pulp, due to the lower cost of non-dissolving pulp, previously in viscose process, utilized the trial of non-dissolving pulp.Yet, due to they deleterious effects to the character of gained viscose solution, so they only can use with low ratio, as packing material, be no more than approximately 5% to 10% of total paper pulp used.

The example of commercially available non-dissolving pulp comprises purchased from the Pearl429 of Fibria, UPM and ENCE (Weyerhauser), Peach (Weyerhauser), Fluff416 (Weyerhauser), Port Wentworth SBSK (Weyerhauser) and Bleached Eucalyptus paper pulp.

Except their solvability, non-dissolving pulp is different in many aspects from dissolving pulp.For example, they have the hemicellulose level higher than dissolving pulp, lower alpha-cellulose content conventionally, for what more do not refine, have the higher polymerization degree (DP) and/or have lower quality control.

Those skilled in the art will know, conventionally the gluing method of implementing comprises step: paper pulp is dissolved or slurrying in caustic soda in caustic soda, in caustic solution, flood, with dithiocarbonic anhydride yellow Mierocrystalline cellulose, and in caustic-alkali aqueous solution, dissolve again to form viscose glue.

Viscose glue is conventionally filtered and refilters so that material purity maximizes, thereby improves product quality.Then adopt technology well known by persons skilled in the art to make it form desired shape, for example, by slit or roller, extrude so that form a slice film, or extrude to form fibrous material by spinning jet.Formed viscose glue contacts with acidity casting liquid subsequently with by viscose glue regenerated cellulose.

The cellulose membrane of extruding also can be by other roller and bath, thereby cleans and softening film obtain required optics and mechanical property.

In some applications, between dipping and yellow step, cellulose slurry or the solution of dipping can alkalize, and wherein remove the alkali cellulose that a part of caustic alkali liquid (for example, by compacting) obtains having target Mierocrystalline cellulose and sodium carbonate (soda) content.The object of this step is to improve cellulosic character, main by reducing its polymerization degree (DP).

If make non-dissolving pulp carry out these conventional steps of implementing, the viscose solution of gained will have unacceptable low filterableness for film forming/shaping application.Even if this detrimentally affect to the filterableness of viscose solution, hindered non-dissolving pulp with higher than slurry approximately 5 % by weight to 10 % by weight ratio and for viscose process.

On the other hand, be optimized to can be used for producing the viscose liquid with high-level filterableness for the dissolving pulp of viscose process.

Can adopt a lot of different testing method to measure filterableness.By obtaining the slope of a curve of being mapped and generated by the viscose glue weight of filter cloth in the interval with five minutes, calculate obstruction constant (Rv).

TVW is the measurement to the total amount of the viscose glue of 30 minutes inner filtrations.

Conventionally, Rv and TVW value are higher, and viscose glue quality is higher, because it can not block or stop up filter cloth.

With the ball settling velocity (BFV) of measuring second, be that the steel ball of counterweight 0.13g+/-0.02g sinks down into the measurement that the degree of depth is time of spending of the bottom of the viscose solution sample of 205mm.

As the substitute technology for quantitative viscose solution quality, can use Counting of fibers method, wherein measure the quantity of residual fiber in solution.

Still need in the art to optimize viscose process so that the non-dissolving pulp of lower cost for Mierocrystalline cellulose working method.

Summary of the invention

Therefore, according to a first aspect of the invention, the method of production of cellulose film or cellulose forming product is provided, it comprises step: the paper pulp of non-solubility cellulose be impregnated in alkaline liquid, the paper pulp of the cellulose of flooding with dithiocarbonic anhydride yellow, the paper pulp of the cellulose of yellow is dissolved in alkaline liquid to form viscose solution, and by viscose solution casting cellulose membrane or cellulose forming product, wherein use one or more in following optimizing machining technology condition: flooding is to carry out at least partly at the temperature of approximately 30 ℃ to approximately 50 ℃; Dipping is to be that approximately 16 % by weight are carried out to the alkaline liquid of approximately 18 % by weight at alkali concn; Yellow is used the dithiocarbonic anhydride of the cellulose approximately 30% to approximately 40% to exist to carry out; Yellow is to carry out at the temperature of approximately 20 ℃ to approximately 30 ℃; Being dissolved to small part is to carry out to the temperature of 25 ℃ at approximately 10 ℃; Dissolving has produced take the viscose solution of solution weight alkali concn as approximately 6% to approximately 7%, and/or, dissolve to have produced and take the viscose solution of solution weight cellulose concentration as approximately 8.5% to approximately 9.5%.

Advantageously, optimizing machining technology condition of the present invention can be used to form high-quality viscose solution, and it is suitable for preparing cellulose membrane or cellulose forming product by non-dissolving pulp.

The method according to this invention and the molded article produced most preferably is fiber.Other products that can also form comprise rope (ropes), yarn, cloth or cigaratte filter.These other products can directly be formed by cellulose solution, or can be formed by the fiber being spun into cellulose solution.

For avoiding doubt, the other procedure of processing of appearance can and be most likely at step a) before and/or in step a) to d) between carry out.Such step will discuss in more detail below.It will be appreciated that, such step can change outward appearance or the character of paper pulp.Therefore, when at step b) and c) in while quoting the paper pulp of cellulose, it being understood that paper pulp will need not to be the form of paper pulp itself, and can be the variant form through processing of paper pulp, the slurries of for example being prepared by non-dissolving pulp, solution or chip.

As mentioned above, technician will appreciate that what thing non-dissolving pulp represents.S/he can be identified the paper pulp with the one or more character in following character: compare with dissolving pulp, relatively high hemicellulose level (being generally approximately more than 10%), relatively low alpha-cellulose content (be generally approximately below 90%, be more typically approximately 83% to approximately 89%), more refining, the relatively high polymerization degree (DP) (being generally approximately 700 to approximately 1200) and/or there is relatively low quality control.

Step a) before, is preferably carried out slurrying or dissolving step.This step is included in solution or the slurries that for example, form the paper pulp of cellulose in alkaline liquid (caustic solution, comprises the alkali metal hydroxide such as sodium hydroxide conventionally).The concentration of the caustic solution using together with dissolving pulp routinely, is 18 % by weight to 20 % by weight.In solution or slurries, cellulosic concentration is generally approximately 2 % by weight to 15 % by weight.

Step a) in, for some time in basic solution by cellulosic solution or slurry.This makes basic solution permeable fiber element, causes part to form Mierocrystalline cellulose alkali salt, for example sodium salt.Alkaline liquid is generally caustic solution, conventionally comprises the alkali metal hydroxide such as sodium hydroxide.

The concentration of the caustic solution using together with dissolving pulp routinely, is 18 % by weight to 20 % by weight.In solution or slurries, cellulosic concentration is generally approximately 2 % by weight to 15 % by weight.Dipping conventionally carries out 10 minutes to 120 minutes and temperature is equal to or greater than approximately 50 ℃.

Can use in the method for the invention some conditions in these method conditions.Yet, surprisingly, found, when making non-dissolving pulp be exposed to the lower time of condition of milder, can obtain favourable result.

Therefore, in a preferred embodiment of the invention, step is a) to be undertaken by non-dissolving pulp being impregnated in the caustic solution of 16% to 18% alkali metal hydroxide.In particularly preferred embodiments, non-dissolving pulp to be impregnated in to alkali metal hydroxide concn be approximately 16.5 % by weight to approximately 17.5 % by weight, approximately 17.5 % by weight to approximately 18 % by weight, approximately 17 % by weight to approximately 18 % by weight, approximately 16.6 % by weight to approximately 17.0 % by weight or approximately 17.2 % by weight to the caustic solution of approximately 17.8 % by weight.The caustic solution of same concentrations can be used in slurrying or dissolving step mentioned above.

Also have been surprisingly found that flooding non-dissolving pulp at than the lower temperature of conventional temperature has produced and can be used for forming the alkali cellulose with the viscose solution that improves performance.Therefore,, in the preferred embodiment of the invention, dipping carries out at least in part at the temperature of approximately 30 ℃ to approximately 50 ℃, approximately 35 ℃ to approximately 48 ℃, approximately 35 ℃ to approximately 45 ℃, approximately 38 ℃ to approximately 42 ℃ or approximately 40 ℃ to approximately 48 ℃.

Find, of the present invention can be for the production of the preferred immersion condition with the viscose solution of good filterableness, the conventional immersion condition using together with same dissolving pulp is compared, and can cause removing hemicellulose still less from cellulose pulp.Thought in the past that the hemicellulose that should remove maximum possible from paper pulp was so that the filterableness maximization of the viscose solution of gained.Yet, have been surprisingly found that, although should remove the natural hemicellulose of vast scale from paper pulp, retain the quality of the viscose solution seem on a small quantity in fact to contribute to gained.

Therefore, in a preferred embodiment of the invention, with the weighing scale of the Mierocrystalline cellulose total amount that exists, the viscose solution that is formed at step (c) preferably comprises 0.1% to approximately 1.0%, approximately 0.8%, approximately 0.6% or approximately 0.5% hemicellulose.

In the viscose process of implementing in routine, manganese can be added in steeping fluid to reduce the DP of cellulose pulp.Conventionally add the amount (with the weighing scale of mixture) of 40ppm to 500ppm.Can use in an identical manner manganese in the method for the invention.

One or more impregnated additive may reside in or are added in the slurries or solution of the cellulose that method of the present invention used.These play a role by making cellulosic structure keep open, and technician will know such material.The example of operable impregnated additive comprises glycerine and/or alcohol alcoxylates, particularly ethoxylated alcohol.These can be added into solution or slurries in any step of the present invention, most preferably in step a) and/or in any slurrying or dissolving step carried out.The example of particularly preferred impregnated additive is Berol388.In use, such as the preferred addition of impregnated additive of Berol388, with cellulose, count approximately 0.1% to approximately 5.0%, approximately 0.5% to approximately 5%, approximately 1% to approximately 4% or approximately 0.5% to approximately 2%.

Additionally or alternatively, one or more swelling agents may reside in or are added in the slurries or solution that the present invention processes.Preferably, in step, a) and/or in any slurrying of carrying out or dissolving step one or more swelling agents are added into slurries or solution.The specific examples of the swelling agent that can use in the methods of the invention comprises propylene glycol, polyoxyethylene glycol, polyvinyl alcohol or polyacrylic ester.

In a preferred embodiment of the invention, starting step b) before, can make to comprise cellulosic slurries or solution and carry out drain step (to remove excessive alkaline liquid, for example, by compacting), broken and/or aging step.If carried out, drain step and/or broken step will preferably produce Mierocrystalline cellulose fragmentary product.

The alkali cellulose product obtaining from any drain step of carrying out preferably includes the approximately Mierocrystalline cellulose below 32% and/or the approximately alkaline matter below 16% (most preferably being alkali metal hydroxide, for example sodium hydroxide).

Routinely, by the alkali cellulose that makes to be formed by dissolving pulp at the temperature more than 30 ℃ and 26% to 29% dithiocarbonic anhydride (with the weighing scale of the fiber that exists), contact to realize yellow.For example, alkali cellulose can be added into the whisk (whisk yellow) of introducing gaseous state dithiocarbonic anhydride, liquid carbon disulphide or the dithiocarbonic anhydride aqueous solution.

It is problematic just finding to use the more dithiocarbonic anhydride of volume before, because found that the formation speed of trithiocarbonic acid sodium (it is the less desirable by product reacting between dithiocarbonic anhydride and caustic solution) improves, particularly when carrying out yellow under intensification.

Although can experience some conventional machining conditions in the yellow step that non-solubility cellulose pulp (or chip, slurries or solution of being formed by this class paper pulp) carries out in the method for the invention, have been surprisingly found that and when adjusting conventional machining condition, obtained optimum.

More specifically, if non-solubility cellulose pulp or the chip, slurries or the solution that are formed by this class paper pulp carry out yellow step, it is preferably below approximately 30 ℃, more preferably carry out at the temperature approximately 20 ℃ to approximately 30 ℃, approximately 22 ℃ to approximately 28 ℃, approximately 24 ℃ to approximately 26 ℃ or approximately 25 ℃ to approximately 30 ℃.

Additionally or alternatively, described paper pulp, chip, slurries or solution preferably with cellulosic weighing scale to exist approximately more than 30% dithiocarbonic anhydride contact, more preferably contact with approximately 30% to approximately 40%, approximately 30% to approximately 35% dithiocarbonic anhydride, approximately 32% to approximately 38% dithiocarbonic anhydride or approximately 34% to approximately 38% dithiocarbonic anhydride.Have been surprisingly found that and be increased in the viscosity that the dithiocarbonic anhydride amount of using during yellow has reduced the viscose solution being formed by yellow Mierocrystalline cellulose.

Step c in the inventive method) in, for example, by non-dissolving pulp (or chip prepared therefrom, slurries or solution) being dissolved in to alkaline liquid (caustic solution, conventionally comprise alkali metal hydroxide, for example sodium hydroxide) in and realize to dissolve.Liquid is preferably moisture.

Preferably using and can producing content of cellulose (CIV) be approximately 5% to 15%, approximately 5% to 13%, approximately 5% to approximately 10% or approximately 7% to approximately 10% and/or amount and the concentration of the alkaline liquid of caustic alkali content (SIV) viscose solution that is approximately 2% to approximately 10%, approximately 4% to approximately 8%, approximately 5.5% to approximately 7.5% or approximately 6% to approximately 7%.

Dissolve preferably at the temperature of approximately 10 ℃ to approximately 25 ℃, approximately 15 ℃ to approximately 20 ℃, approximately 18 ℃ to approximately 22 ℃ or approximately 16 ℃ to approximately 18 ℃ and carry out.

In the method for the invention, can carry out alkalinization step.This will be preferably after dipping and/or carry out before yellow.The object of alkalinization step is to improve cellulosic character contained in paper pulp, for example, and by reducing the cellulosic polymerization degree.

As the branch as viscose process and conventional implement, alkalinization step comprises that slurries or the solution in alkaline liquid is removed a part of alkaline liquid (and optionally adding fresh alkaline liquid) from disappearing fibre element paper pulp, thereby obtain target content of cellulose and/or target alkali or carbonate content, for example, at least about 33% Mierocrystalline cellulose and/or at least about 16% alkali.

Alternatively, in the methods of the invention, different target Mierocrystalline cellulose and/or alkali contents can be preferably.More specifically, in preferred version of the present invention, alkali cellulose product the best comprises the approximately Mierocrystalline cellulose below 32% and/or the approximately alkaline matter below 16% (most preferably being alkali metal hydroxide, for example sodium hydroxide).

In optional embodiment of the present invention, alkalinization step can be got rid of outside described method.In one embodiment of the invention, by through impregnation steps, (slurries of step cellulose a) or solution are cooling to prevent that alkalization from occurring.For example, can make solution or mixture be cooled to approximately 50 ℃ of following, approximately 40 ℃ of following, approximately 30 ℃ of following temperature or most preferably to approximately 25 ℃ of following temperature.

The viscose solution being formed by the paper pulp of processing according to the inventive method preferably has at least 400, more preferably at least 500, at least 600 or at least 700 K value.

Additionally or alternatively, the viscose solution being formed by the paper pulp of processing according to the inventive method preferably has one or more in following characteristic: Rv is more than approximately 200, more preferably from about more than 500, TVW is approximately more than 100, and fibre count be approximately 100 fibers/gram following or more preferably 20 fibers/gram below.

Generally speaking, due to the condition of the favourable and optimization of implementing as a part of the present invention, can prepare the viscose solution being formed by non-dissolving pulp completely.Yet those skilled in the art may still wish to produce viscose solution by the mixture of dissolving and non-dissolving pulp.Therefore, in a preferred method of the invention, the paper pulp using in the inventive method at least about 15%, will be non-dissolving pulp.In other words, that in step (a), in viscose solution dipping and/or that form in step (c) in, exist and/or in step (d), cast exist in cellulose membrane or cellulose forming product viscose solution used cellulosic and will be obtained by non-dissolving pulp at least about 15%.

In a more preferred embodiment, that in step (a), in viscose solution dipping and/or that form in step (c) in, exist and/or in step (d), cast exist in cellulose membrane or cellulose forming product viscose solution used cellulosic and will be obtained by non-dissolving pulp at least about 25%, approximately 50%, approximately 70%, approximately 90%, approximately 95% or even approximately 98%.

Method of the present invention further comprises from the step of viscose solution casting cellulose membrane or cellulose forming product.Technology for this will be well known to a person skilled in the art.

For example, in some preferred embodiment of the present invention, when casting cellulose membrane, can use routine casting technology, wherein solution extrudes to form desired shape by slit.Then the material of extruding is contacted with casting liquid, for example, by being fed in casting bath.

The cellulose membrane of extruding also can and bathe to clean and softening film by other roller, and to obtain required optics and mechanical properties.

In other preferred embodiments, when molded article is cellulosic fibre, those fibers preferably form by extruding cellulose solution via spinning jet, thus producd fibers shape material.Yet, can use any fiber to form technology and equipment.

Similarly, in embodiments of the invention, when prepared fiber-forming goods by cellulose solution but not during fiber, can adopt routine techniques well known by persons skilled in the art to make cellulose solution molded, form or be configured as required configuration.

In addition, formed the embodiment of cellulosics therein by the fiber of making from cellulose solution, cellulosic fibre can be used any technology well known by persons skilled in the art and change into those goods.

Subsequently, the cellulose solution of shaping is preferably transferred to and comprises in the casting bath of casting liquid.

For the quality of viscose solution prepared according to the methods of the invention is maximized, except dipping, yellow dissolving and casting, can make the paper pulp of cellulose wherein used carry out one or more treatment steps.

For example, can make the paper pulp of cellulose carry out electron beam treatment.The paper pulp of processing cellulose with electron beam irradiation is known, and for commercial process for many years.Conventionally for example, by pulp layer or sheet being sent to (using handling machinery) near stationary electron beams source, use the pulp processing of electron beam irradiation.

Electron beam irradiation can be from the transmitting of any amount of position, for example, from one, two, three, four, five or six position transmittings.Yet in preferred aspects of the invention, electron beam irradiation is launched from two positions, most preferably, from the above and below transmitting of paper pulp.Electron beam irradiation can be from single, fixing or movably electron beam source transmitting, or from a plurality of can be that fixed or movable electron beam source is launched independently.From the transmitting of the electron beam irradiation of a plurality of positions can be simultaneously or order.

The voltage of the electron beam irradiation that preferably, non-dissolving pulp exposes will be same as or lower than conventional electrical bundle treatment process voltage used.For example, from one, the ejected electron bundle radiation of some or all of positions will be for below about 10meV, below about 5meV, below about 1.5meV, below about 1.0meV, below about 800keV, below about 600keV, below about 500keV, below about 400keV, below about 300keV, below about 250keV or below even about 200keV.

Well known by persons skilled in the artly anyly can launch the voltage of required radiation and the electron beam evaporation equipment of dosage may be used in method of the present invention.

For example, can use and can under the voltage of 750keV to 1.5meV, send the middle pressure device of doses of electron beam radiation.Use the processing service of such device to be provided by many companies, for example AquaMed.Such equipment is favourable, because paper pulp process velocity (being processing speed) is for high.

Additionally or alternatively, can use low-voltage device.Such device is generally used for coating curing system, and the example of this kind equipment is at least provided by PCT Engineering Systems at UK.This equipment can be at height to the curtain formula beam dose of sending electron beam irradiation under the voltage of 300keV.Beamwidth is adjustable, depends on paper pulp area to be processed, and realizes processing with the consistence of acceptable level.Transmitting due to the electron beam irradiation of relatively low pressure, so need minimal shielding, make equipment more operationally for from a plurality of positions pulp treatment and/or for simultaneously and/or sequentially carry out pulp treatment with a plurality of described device of different positions, and to user's the health any risk of tool not.

In certain embodiments, preferably, use from the electron beam irradiation of the equivalent of different positions and process non-dissolving pulp.Yet, in optional scheme, from the radiation quantity of different positions transmitting, changed below about 100keV, below about 80keV, below about 60keV, below about 50keV, below about 40keV, below about 30keV, below about 20keV, below about 10keV, or below about 5keV.

The total dose of the electron beam irradiation that paper pulp exposes can change.In preferred aspects of the invention, paper pulp is exposed to the electron beam irradiation of following dosage, described dosage be about about 0.5mRad to about 5.0mRad (about 5kgy to about 50kgy), about 1.0mRad to about 4.0mRad (about 10kgy is to about 40kgy), about 1.5mRad to about 3.5mRad (about 15kgy is to about 35kgy), about 2.0mRad to about 3.0mRad (about 20kgy is to about 30kgy) or about 1.0mRad to about 2.0mRad (about 10kgy is to about 20kgy).Therein paper pulp is supplied with to process electron beam so that paper pulp is exposed in the embodiment of radiation, can be controlled feed speed to guarantee to give target dosage.

The dosage of the radiation that non-dissolving pulp exposes and voltage can change according to the source of paper pulp to be processed, density, area, thickness and/or weight.The thickness of the paper pulp of processing according to the present invention can be for about 0.1mm, about 0.5mm, about 1.0mm, about 5.0mm or 10.0mm be to about 100mm, about 50mm, about 20mm, about 15mm or about 10mm.The weight of handled paper pulp can be about 200g/m in the methods of the invention ², about 400g/m ², about 600g/m ², or about 700g/m ²to about 2000g/m ², about 1500g/m ², about 1200g/m ², about 1000g/m ², or about 800g/m ².

Non-dissolving pulp can be continuously (for example,, by using e Foerderanlage) or be exposed to off and on electron beam irradiation.

Treated paper pulp preferably has below approximately 600, below approximately 500, below approximately 400 or the polymerization degree below 300 most preferably from about.This polymkeric substance with respect to untreated non-dissolving pulp (it typically is approximately 800 to 1400) has formed significant improvement.Surprisingly, can obtain these favourable results with voltage and/or the dosage of the radiation significantly lower than the radiation of routine use.

Additionally or alternatively, have other treatment steps that the paper pulp that uses in the inventive method can carry out.

For example, in the situation of fluff pulp, these can be with sheet form supply, and can expect to make their fluffings (fluff) or pulverize, for example, use high-shear mixer.

Additionally or alternatively, paper pulp can carry out drying step, for example, by being placed on baking oven and being heated to for example temperature of approximately 40 ℃ to 100 ℃.

As other treatment steps, can be by paper pulp layering.

In a preferred embodiment of the invention, the Temperature Treatment that paper pulp is reduced.Do not wish to be limited to theory, should be sure of that the fiber properties of wood pulp is destroyed by making paper pulp be exposed to low temperature, may destroy hydrogen bonded and cellulosic fibre is more easy to get.

The Temperature Treatment reducing realizes by making paper pulp be exposed to low temperature, for example 0 ℃ following ,-50 ℃ following ,-100 ℃ following ,-150 ℃ following or below-180 ℃.

The Temperature Treatment reducing can for example, by storing paper pulp or remaining on low temperature environment, implement in industrial freezer.Additionally or alternatively, paper pulp can be exposed in low temperature agent, cryogenic liquid for example, as liquid nitrogen, liquid helium, liquid hydrogen, liquid oxygen, liquid neon or their mixture.If use the agent of liquid low temperature, preferably make paper pulp soak into and/or be immersed in wherein.

In preferred version, the time length of the Temperature Treatment of reduction be approximately 60 minutes following, more preferably from about 30 minutes following, approximately 20 minutes following or below approximately 15 minutes.

According to a second aspect of the invention, provide cellulose membrane or the cellulose forming product obtaining according to the method for first aspect present invention.

For avoiding any doubt, in appropriate circumstances, the reference of feature to the first aspect of the present invention discussed above is optionally suitable for the product of second aspect present invention.

Now, will in following examples, set forth the present invention, described embodiment shows that optimization viscose glue processing conditions of the present invention can be for producing high-quality viscose solution by non-dissolving pulp.

Embodiment

Embodiment 1: the NaOH concentration of optimizing immersion condition-steeping fluid

Studied for flooding the concentration affects of alkaline liquid of the paper pulp of cellulose.At 50 ℃, soft wood dissolving pulp be impregnated in the sodium hydroxide solution that concentration is 18.3 % by weight and 17.5 % by weight to 30 minutes.Adopt conventional processing conditions by slurries alkalinisation treatment (mercerized), yellow and the dissolving of gained.

Gained viscose solution has following character:

Table 1:

Dipping NaOH concentration (%)	Rv	Fibre count/g	Nian Du – BFV (s)
				18.3	12.1	160+	78
17.5	289.9	77	51

Therefore, can find out, the small size reduction of steeping fluid NaOH concentration has remarkably influenced to the quality of gained viscose solution.

Embodiment 2: the NaOH concentration of optimizing immersion condition-steeping fluid

According to following processing conditions Making viscose solution.Can find out, unique variable is the concentration for the caustic solution of impregnation of fibers element.

At 40 ℃, it is in 16%, 16.8%, 17.1%, 17.5% and 18.3% sodium carbonate (soda) 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to caustic sodium concentration.Then use the CS of the cellulose meter 31% that exists ₂carry out yellow, temperature of reaction is 30 ℃.Then the cellulose dissolution of yellow be take produce sodium carbonate (SIV) content in final target viscose glue as 6.5% and viscose glue in Mierocrystalline cellulose (CIV) the content viscose solution that is 9.3%.Viscose glue has following character, and described character is also depicted in the chart that Fig. 1 provides:

Table 2

Again, these data have determined from routine, for flooding the small size reduction of NaOH concentration of the steeping fluid of dissolving pulp, the quality of the viscose solution of being prepared by non-dissolving pulp is had to remarkably influenced.

Embodiment 3: the immersion condition-dipping temperature of optimization

According to following processing conditions Making viscose solution.Can find out, unique variable is the temperature of flooding.

At 20 ℃, 40 ℃, 50 ℃ and 60 ℃, it is in 17.1% liquid 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to NaOH concentration.The CS of the cellulose meter 31% that then it is used to exist ₂at the temperature of 30 ℃, carry out yellow.Then products therefrom is dissolved at 17.3 ℃ take obtain Mierocrystalline cellulose (CIV) content in viscose glue as 9.3% and viscose glue in sodium carbonate (SIV) the content viscose solution that is 6.5%.

Fig. 2 has determined that dipping temperature has remarkably influenced to final viscose glue quality, and the optimum temps of tested paper pulp is 40 ℃.

Embodiment 4: optimize dipping

Use following processing conditions by Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) Making viscose solution:

Table 3

Change condition is provided in Fig. 3 a and 3b the impact of gained viscose solution character, and described impact presents according to their filtration weight (it was based on 5 minutes intervals and illustrate cumulatively).

Embodiment 5: the amount of optimizing yellow-dithiocarbonic anhydride

According to following processing conditions Making viscose solution.Can find out, unique variable is the amount of the dithiocarbonic anhydride that uses in yellow step.

At 40 ℃, it is in 17.5% liquid 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to NaOH concentration.Then the cellulose meter 26%, 31%, 33% that it is used to exist and 36% CS ₂at the temperature of 30 ℃, carry out yellow.Then products therefrom is dissolved at 17.3 ℃ take obtain Mierocrystalline cellulose (CIV) content in viscose glue as 9.3% and viscose glue in sodium carbonate (SIV) the content viscose solution that is 6.5%.

The Rv of gained viscose solution, TVW and BFV value are provided in Fig. 4.Can find out, the amount of dithiocarbonic anhydride is increased to and surpasses the conventional level of using, and has advantageously caused the increase of TVW and Rv and the minimizing of BFV.

Embodiment 6: optimize yellow-yellow temperature

According to following processing conditions Making viscose solution.Can find out, unique variable is the temperature of carrying out yellow step.

At 40 ℃, it is in 17.5% liquid 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to NaOH concentration.The CS of the cellulose meter 31% that then it is used to exist ₂at the temperature of 25 ℃, 30 ℃ and 40 ℃, carry out yellow.Then products therefrom is dissolved at 17.3 ℃ take obtain Mierocrystalline cellulose (CIV) content in viscose glue as 9.3% and viscose glue in sodium carbonate (SIV) the content viscose solution that is 6.5%.

The Rv of gained viscose solution, TVW and BFV value are provided in Fig. 5.Can find out, at lower temperature, carry out that yellow has caused the TVW not expecting and Rv increases and the minimizing of BFV comparing with the conventional temperature of using of dissolving pulp.

Embodiment 7: the yellow of optimization

Table 4

Change condition is provided in Fig. 6 a and 6b the impact of gained viscose solution character, and described impact presents according to their filtration weight (it was based on 5 minutes intervals and illustrate cumulatively).

Embodiment 8: optimize dissolving-SIV content

According to following processing conditions Making viscose solution.Can find out, unique variable is the SIV content of viscose glue.

At 40 ℃, it is in 17.5% liquid 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to NaOH concentration.The CS of the cellulose meter 31% that then it is used to exist ₂at the temperature of 25 ℃, carry out yellow.Then products therefrom is dissolved at 17.3 ℃ take obtain Mierocrystalline cellulose (CIV) content in viscose glue as 9.3% and viscose glue in sodium carbonate (SIV) the content viscose solution that is 5.5%, 6%, 6.5% and 7%.

The Rv of gained viscose solution, TVW, BFV and fibre count value are provided in Fig. 7.Can find out, the SIV content of 6.5% left and right has caused best Rv, TVW and the fibre count value of tested viscose solution.

Embodiment 9: optimize dissolving-SIV content

Table 5

Change condition is provided in Fig. 8 a and 8b the impact of gained viscose solution character, and described impact presents according to their filtration weight (it was based on 5 minutes intervals and illustrate cumulatively).

Embodiment 10: optimize dissolving-solvent temperature

According to following processing conditions Making viscose solution.Can find out, unique variable is the temperature that dissolving occurs.

At 40 ℃, it is in 17.5% liquid 15 minutes that Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) be impregnated in to NaOH concentration.The CS of the cellulose meter 31% that then it is used to exist ₂at the temperature of 25 ℃, carry out yellow.Then products therefrom is dissolved at 10 ℃, 17.3 ℃ and 30 ℃ take obtain Mierocrystalline cellulose (CIV) content in viscose glue as 9.3% and viscose glue in sodium carbonate (SIV) viscose solution that is content 6.5%.

The Rv of gained viscose solution and TVW value are provided in Fig. 9.Can find out, the solvent temperature of 17 ℃ of left and right has caused best Rv and the TVW value of tested viscose solution.

The summary of embodiment 1-10

The data of reporting in a plurality of embodiment are above incorporated in the summary sheet that Figure 10 provides.What in those tests, obtain preferably illustrates based on testing one by one with the poorest Rv and TVW result, can find out, when using optimal conditions of the present invention, improves significantly.

Importantly, in first category (' totally '), when using together with non-dissolving pulp, between the best result obtaining use optimizing machining technology condition of the present invention and conventional machining condition (using) together with dissolving pulp, compare.When using optimizing machining technology condition of the present invention, can clearly observe remarkable improvement; Rv is increased to 237.5 from 13.9, and TVW is increased to 184.5 from 18.1.Therefore, the processing conditions of the application of the invention, advantageously (now may for first) preparation is suitable for being formed by non-dissolving pulp the high-quality viscose solution of cellulose membrane or cellulose forming product.

Embodiment 11: the impact of hemicellulose on viscose solution

Under the temperature, time and the concentration that change, make the NaOH slurrying of Weyerhauser Pearl paper pulp (a kind of non-dissolving pulp) Yu the 1800ml of 89.2g.Then use slurry press to press down slurrying liquid 30 seconds at 7 tons.Collect excessive NaOH, weigh and test hemicellulose level.

In these tests, the primary variables of research is dipping temperature and dipping caustic sodium concentration, and the result of this experiment is provided in Figure 11 a and 11b.Can find out, at 40 ℃, with the caustic solution that concentration is 17% left and right, flood the hemicellulose that non-dissolving pulp has caused extracting minimum ratio from paper pulp.

Recognized in the past in order that hemicellulose has negative influence to the filterableness of viscose solution.Yet, from relatively can finding out of the result shown in Figure 11 a and 11b and the result shown in Fig. 1 and 2, cause removing the immersion condition of hemicellulose of minimum ratio corresponding to the immersion condition that causes having the viscose solution of optimum filtration.

Claims

1. for the production of the method for cellulose membrane or cellulose forming product, it comprises step:

A. the paper pulp of non-solubility cellulose be impregnated in alkaline liquid,

B. with the paper pulp of the cellulose of flooding described in dithiocarbonic anhydride yellow,

C. the paper pulp of the cellulose of described yellow is dissolved in alkaline liquid to form viscose solution, and

D. by described viscose solution, cast cellulose membrane or cellulose forming product,

Wherein use one or more in following optimizing machining technology condition:

Dipping is to carry out at the temperature of approximately 30 ℃ to approximately 50 ℃ at least in part,

Dipping is to be that approximately 16 % by weight are carried out to the alkaline liquid of approximately 18 % by weight at alkali concn,

Yellow is to use the dithiocarbonic anhydride of the cellulosic weighing scale approximately 30% to approximately 40% to exist to carry out,

Yellow is to carry out at the temperature of approximately 20 ℃ to approximately 30 ℃ at least in part,

Dissolving is to carry out to the temperature of 25 ℃ at approximately 10 ℃ at least in part,

Dissolve and produce in solution weight, alkali concn is approximately 5.5% to approximately 7.5% viscose solution, and/or

Dissolve and produce in solution weight, cellulose concentration is approximately 8.5% to approximately 9.5% viscose solution.

2. the method for claim 1, wherein dipping is to be that approximately 16.5 % by weight are carried out to the alkaline liquid of approximately 17.5 % by weight at alkali concn.

3. method as claimed in claim 1 or 2, wherein dipping is to carry out at the temperature of approximately 40 ℃ to approximately 48 ℃ at least in part.

4. method as claimed any one in claims 1 to 3, wherein dipping is to carry out at the temperature of approximately 35 ℃ to approximately 45 ℃ at least in part.

5. the method as described in any one in claim 1 to 4, wherein dipping is to carry out in substantially not containing the slurries of manganese or solution.

6. the method as described in any one in claim 1 to 5, wherein dipping is what in the slurries that contain impregnated additive or solution, to be carried out.

7. method as claimed in claim 6, wherein said impregnated additive is ethoxylated alcohol.

8. the method as described in claim 6 or 7, wherein said impregnated additive is Berol388.

9. the method as described in any one in claim 1 to 8, wherein before yellow, makes the paper pulp of described cellulose or slurries prepared therefrom or solution carry out the one or more steps in drain step, broken step and/or aging step.

10. method as claimed in any one of claims 1-9 wherein, wherein yellow is the cellulosic weighing scale using to exist, approximately 32% to approximately 38% dithiocarbonic anhydride carries out.

The content of cellulose of the described viscose solution of 11. methods as described in any one in claim 1 to 10, wherein with the weighing scale of solution, step c) preparing is approximately 5% to approximately 10%.

12. methods as described in any one in claim 1 to 11, wherein dissolving is to carry out at the temperature of approximately 15 ℃ to approximately 20 ℃ at least in part.

13. methods as described in any one in claim 1 to 12, wherein a) time, reduce to prevent that by the temperature of described slurries or solution alkalization from occurring at completing steps.

14. methods as described in any one in claim 1 to 13, wherein at step c) in the viscose solution that forms have take lower one or more: Rv as approximately more than 200, TVW as approximately more than 100 and/or fibre count as approximately 100 fibers/gram below.

15. methods as described in any one in claim 1 to 14, wherein at step c) in the viscose solution that forms have following one or more: Rv be approximately more than 500 and/or fibre count be 20 fibers/gram below.

16. methods as described in any one in claim 1 to 15, wherein at step c) in the K value of the viscose solution that forms be at least about 400.

17. methods as described in any one in claim 1 to 16, wherein at step c) in the K value of the viscose solution that forms be at least about 600.

18. methods as described in any one in claim 1 to 17, wherein in step a) before, make described paper pulp be selected from the one or more other treatment step of the Temperature Treatment of electron beam irradiation, fluffing, fragmentation, dry, layering and/or reduction.

19. methods as claimed in claim 18, wherein electron beam irradiation comprises and makes the paper pulp of non-solubility cellulose be exposed to electron beam irradiation.

20. methods as claimed in claim 19, wherein said electron beam irradiation is derived from a plurality of positions.

21. methods as described in claim 19 or 20, wherein electron beam irradiation is launched from two positions.

22. methods as described in any one in claim 19 to 21, wherein electron beam irradiation be on described paper pulp and under position transmitting.

23. methods as described in any one in claim 19 to 22, wherein the voltage of the one or more positions ejected electron bundle radiation in described a plurality of positions is below about 1.5meV.

24. methods as described in any one in claim 19 to 23, wherein the voltage of the one or more positions ejected electron bundle radiation in described a plurality of positions is below about 500keV.

25. methods as described in any one in claim 20 to 24, wherein being changed to below about 50keV from the voltage of described a plurality of positions ejected electron bundle radiation.

26. methods as described in any one in claim 19 to 25, the dosage of the electron beam irradiation that wherein said paper pulp exposes is that about 0.5mRad is to about 5.0mRad.

27. methods as described in any one in claim 19 to 26, the dosage of the electron beam irradiation that wherein said paper pulp exposes is that about 1.5mRad is to about 3.5mRad.

28. methods as described in any one in claim 19 to 27, the thickness of wherein said paper pulp is that about 0.1mm is to about 100mm.

29. methods as described in any one in claim 19 to 28, the weight of wherein said paper pulp is about 200g/m ²to about 1200g/m ².

30. methods as described in any one in claim 19 to 29, wherein, after being exposed to electron beam irradiation, the mean polymerisation degree of described paper pulp is approximately below 500.

31. methods as described in any one in claim 19 to 30, wherein, after being exposed to electron beam irradiation, the mean polymerisation degree of described paper pulp is approximately below 400.

32. methods as described in any one in claims 1 to 31, wherein in step (a), in solution dipping and/or that form in step (c) in, in solution that exist and/or cast described cellulose membrane or described cellulose forming product in step (d) in, exist cellulosic at least about 15%, be by treated non-dissolving pulp acquisition.

33. methods as described in any one in claims 1 to 32, wherein in step (a), in solution dipping and/or that form in step (c) in, in solution that exist and/or cast described cellulose membrane or described cellulose forming product in step (d) in, exist cellulosic at least about 50%, be by treated non-dissolving pulp acquisition.

34. methods as described in any one in claims 1 to 33, wherein in step (a) dipping and/or the solution that forms in step (c) in exist in solution that exist and/or cast described cellulose membrane or described cellulose forming product in step (d) in cellulosic at least about 90%, be by treated non-dissolving pulp acquisition.

35. methods as described in any one in claims 1 to 34, wherein said molded article is fiber.

36. methods as described in any one in claims 1 to 34, wherein said molded article is rope, yarn, cloth or cigarette filter.

37. methods as claimed in claim 35, it also comprises makes steps d) in the cellulosic fibre of casting form the step of goods.

38. methods as claimed in claim 37, wherein said goods are rope, yarn, cloth or cigarette filter.

39. cellulose forming products that the method described in any one obtains in claims 1 to 38.

40. cellulose membranes that the method described in any one obtains in claims 1 to 34.