阅读说明：本技术 包含微原纤化纤维素和微原纤化二醛纤维素的阻隔膜和制造阻隔膜的方法 (The method of barrier film comprising microfibrillated cellulose and micro- fibrillation dialdehyde cellulose and manufacture barrier film ) 是由 C.兰德亨斯达尔 A.斯文森 L.伯格奎斯特 A.特伦卡尔斯特罗姆 L.阿克斯鲁普 于 2018-04-11 设计创作，主要内容包括：本发明涉及制造膜的至少一个层的方法,其中所述方法包括以下步骤；提供包含微原纤化纤维素的第一悬浮体,提供包含微原纤化二醛纤维素的第二悬浮体,将第一悬浮体与第二悬浮体混合以形成混合物,将所述混合物施加至基底以形成纤维幅材以及干燥所述幅材以形成所述膜的至少一个层。本发明还涉及包含所述至少一个层的膜。(The present invention relates to the methods of at least one layer of manufacture film, wherein the described method comprises the following steps；The first suspended substance comprising microfibrillated cellulose is provided, the second suspended substance comprising micro- fibrillation dialdehyde cellulose is provided, first suspended substance and the second suspended substance are mixed to form mixture, the mixture is applied to substrate to form fiber web and the dry web to form at least one layer of the film.The invention further relates to the films comprising at least one described layer.)

1. the method for manufacturing at least one layer of film, the method comprise the steps that

The first suspended substance comprising microfibrillated cellulose is provided,

The second suspended substance comprising micro- fibrillation dialdehyde cellulose is provided,

First suspended substance and the second suspended substance are mixed to form mixture,

The mixture is applied to substrate with formed fiber web and

The web is dried to form at least one layer of the film.

2. according to the method described in claim 1, wherein mixture include 20-95 weight % micro- fibrillation dialdehyde cellulose, Based on the total fiber weight of mixture.

3. method according to any of the preceding claims, wherein mixture includes micro- fibril chemical fibre of 5-80 weight % Dimension element, based on the total fiber weight of mixture.

4. method according to any of the preceding claims, wherein the dry content for being applied to the mixture of substrate is 1-10 Weight %.

5. method according to any of the preceding claims, wherein at least one described layer of film is according to ASTM D- 3985, the OTR oxygen transmission rate under 50% relative humidity at 23 DEG C and/or under 90% relative humidity at 38 DEG C is 0.1 to 300cc/m²/24h。

6. method according to any of the preceding claims, wherein substrate is polymer or metallic substrates.

7. method according to any of the preceding claims, wherein the method also includes the steps of squeeze film after drying Suddenly.

8. according to the method described in claim 7, wherein temperature is improved to 100-150 DEG C during squeeze film.

9. method according to any of the preceding claims, wherein the mixture further includes below any: forming sediment Powder, carboxymethyl cellulose, filler, retention chemicals, coagulation additives, deflocculation additive, dry strength additive, softening agent, Or mixtures thereof.

10. method according to any of the preceding claims, wherein micro- fibrillation dialdehyde fiber in the second suspended substance The degree of oxidation of element is 25-75%.

11. including the film of microfibrillated cellulose, wherein the OTR oxygen transmission rate of film is 0.1 to 300cc/m²/ for 24 hours, according to ASTM D-3985 is measured at 23 DEG C and/or under 90% relative humidity at 38 DEG C under 50% relative humidity, and wherein At least one layer of film includes the mixture of microfibrillated cellulose and micro- fibrillation dialdehyde cellulose.

12. film as claimed in claim 11, wherein the quantification of of film is less than 50g/m², preferably 10-50g/m²。

13. the film as described in claim 11 or 12, wherein the film is the multilayer film comprising more than one layer.

14. the film as described in any one of claim 11-13, wherein the film is multilayer film and wherein at least one layer of film For vapor water barriers film, it includes below any: polyethylene (PE), polypropylene (PP), polyamide, poly terephthalic acid second Diol ester (PET) or ethylene-vinyl alcohol (EVOH).

15. film according to claim 14, wherein the grammes per square metre of vapor water barriers film is 10 to 60g/m², preferably 30 to 50g/ m²。

16. film described in any one of 1-15 according to claim 1, wherein the film is multilayer film and wherein at least one of film Layer is the barrier layer of metallization.

17. film according to claim 16, wherein the barrier layer of the metallization is the metal or gold of physical vapour deposition (PVD) Belong to the metal or metal oxide layer of oxide skin(coating) or chemical vapor deposition.

18. film according to claim 17, wherein the metal or metal oxide are selected from aluminium, aluminium oxide, magnesia, oxygen SiClx, copper, magnesium and silicon.

19. film described in any one of 6-18 according to claim 1, wherein the weight of the barrier layer of the metallization be 50 to 250mg/m², preferably 75 to 150mg/m²。

20. packaging material, it includes at least one layers of basic material and the film as described in any one of claim 11-19.

21. packaging material according to claim 20, wherein basic material is Paper or cardboard.

22. packaging material according to claim 21, wherein the grammes per square metre of Paper or cardboard is 20 to 500g/m²。

23. packaging material according to claim 21, wherein the grammes per square metre of Paper or cardboard is 80 to 400g/m²。

Technical field

The present invention relates to the barrier films at high relative humidity (RH) with good and stable OTR oxygen transmission rate (OTR). More particularly, it relates to method and the film produced of film as manufacturing.

Background technique

Currently, the film comprising microfibrillated cellulose (MFC) is verified to provide excellent barrier property (see for example Aulin etc., Oxygen and oil barrier properties of microfibrillated cellulose films And coatings, Cellulose (2010) 17:559-574, Lavoine etc., Microfibrillated cellulose- Its barrier properties and applications in cellulosic materials:A review, Carbohydrate polymers 90 (2012) 735-764, Kumar etc., Comparison of nano-and Microfibrillated cellulose films, Cellulose (2014) 21:3443-3456), and gas barrier property The moisture or relative humidity being highly dependent in ambient enviroment.Therefore, very common is that must coat MFC film with polymer film To prevent water point or vapor from making MFC membrane swelling or destroy MFC film.

The shortage of gas barrier property (such as oxygen or air) under high relative humidity has been obtained research and retouches The most of scheme stated, but proposed is expensive and is difficult to implement at industrial scale.A kind of approach is to MFC or Nanowire Dimension element is modified, such as disclosed in EP2554589A1, wherein being changed with silane coupling reagent to MFC dispersion Property.EP2551104A1 is taught using the MFC and polyethylene at higher relative humidity (RH) with improved barrier property Alcohol (PVOH) and/or polyuronic acid.Another program is should with the film coating with enhanced water resistance and/or low moisture-vapor transmission Film.JP2000303386A is disclosed for example coated in the latex on MFC film, at the same US2012094047A teach use with it is more The wood hydrolysate of sugared (such as MFC) mixing, can be coated with polyolefin layer.Other than this chemical modification, also study A possibility that crosslinking fibrinogen or fibrinogen and copolymer.Which improve the water resistance of film and moisture-vapor transmissions. EP2371892A1, EP2371893A1, it is desirable that protect respectively with metal ion, glyoxal, glutaraldehyde and/or citric acid crosslinking MFC。

Reduce cellulose water sensitivity another way be with sodium metaperiodate to cellulose carry out chemical modification with It obtains dialdehyde cellulose (DAC).By the way that the barrier film with improved water resistance can be produced by dialdehyde cellulose fibrillation.So And the dispersion comprising micro- fibrillation dialdehyde cellulose (DA-MFC) is highly unstable, because of DA-MFC in dispersions Can deposit and it is spontaneous be cross-linked to certain degree so that microfibril combines or tangles.In addition, the difference of dispersion Stability also results in the variation of DA-MFC concentration in film, causes the film forming (film formation) of difference and therefore causes not Good barrier property.

Therefore need to find production even the simple scheme also at high humidity with the film of good barrier property.

Summary of the invention

The object of the present invention is to provide the improved film comprising microfibrillated cellulose, the higher phase even around To under humidity also have improved barrier property.

The object of the present invention is to provide the improved film comprising microfibrillated cellulose, even if in the feelings of moisture fluctuation Also good barrier property is able to maintain under condition.

The present invention is defined in the accompanying independent claim.Embodiment is in appended dependent claims and following retouches It states and is illustrated in attached drawing.

The present invention relates to the methods of at least one layer of manufacture film, wherein the described method comprises the following steps；Offer includes First suspended substance of microfibrillated cellulose provides the second suspended substance comprising micro- fibrillation dialdehyde cellulose, and first is suspended Body and the second suspended substance are mixed to form mixture, and the mixture is applied to substrate to form fiber web and dry institute Web is stated to form at least one layer of the film.It has surprisingly found that by mixing comprising microfibrillated cellulose First suspended substance and the second suspended substance comprising micro- fibrillation dialdehyde cellulose can produce highly stable suspended substance or mixture. It is essential that the suspended substance for producing barrier material be it is stable because the non-uniform distribution of fibrinogen will cause it is bad The barrier property of change.It moreover has been found that using the microfibrillated cellulose of the first suspended substance and micro- fibril chemical fibre of the second suspended substance It ties up both plain (DA-MFC) and makes at least one layer that can produce film, assign film improved barrier property at high humidity, Especially under the humidity of fluctuation.

Mixture preferably comprises micro- fibrillation dialdehyde cellulose of 20-95 weight %, the total fiber weight based on mixture Meter.Mixture preferably comprises the microfibrillated cellulose of 5-80 weight %, based on the total fiber weight of mixture.Depending on most The property of whole purposes and the microfibrillated cellulose of the first suspended substance and the second suspended substance, the amount of micro- fibrillation dialdehyde cellulose It is alterable.

The dry content for being applied to the mixture of substrate is preferably 1-10 weight %.Depend on the base for being applied with mixture thereon The dry content at bottom, mixture is alterable.

At least one described layer of film advantageously according to ASTM D-3985, under 50% relative humidity at 23 DEG C and/ Or the OTR oxygen transmission rate under 90% relative humidity at 38 DEG C is 0.1 to 300cc/m²/24h.It can produce through the invention At least one layer of film has very good oxygen obstruction property at high humidity.Particular, it is found that according to the present invention Film tolerance is had more to the fluctuation of humidity, even if that is, film still has good barrier property in the case where humidity changes.

Substrate is preferably polymer or metallic substrates.Preferably mixture is by curtain coating coating to the substrate.

The step of this method can further comprise squeeze film after drying.It has shown that if film is subjected to improving after the drying Pressure, then the barrier property of film is improved.The pressure applied in extruding is preferably higher than 40kN/m (over-voltage, over Pressure), more preferably 100-900kN/m.During the extruding of film, temperature is preferably improved to 50-200 DEG C, preferably 100- 150℃。

Mixture can further include additive, preferably below any: starch, carboxymethyl cellulose, filler, retention Or mixtures thereof chemicals, coagulation additives, deflocculation additive, dry strength additive, softening agent,.Can add can improve it is mixed Close the additive of different nature of object and/or film produced, such as the latex and/or polyethylene of the ductility for enhancing film Alcohol.The first suspended substance, the second suspended substance can be added an additive to and/or be added to mixture.

According to an aspect of the present invention, the degree of oxidation of micro- fibrillation dialdehyde cellulose in the second suspended substance is 25- 75%.

The invention further relates to the film comprising microfibrillated cellulose, wherein the OTR oxygen transmission rate of the film be 0.1 to 300cc/m²/ for 24 hours, according to ASTM D-3985, under 50% relative humidity at 23 DEG C and/or 90% relative humidity Under measured at 38 DEG C, and wherein at least one layer of film includes the mixed of microfibrillated cellulose and micro- fibrillation dialdehyde cellulose Close object.

Film is quantitatively preferably smaller than 50g/m², preferably 10 to 50g/m²。

Film is preferably the multilayer film for including more than one layer.

According to an aspect of the present invention, at least one layer of multilayer film includes the latex for enhancing the ductility of film.

According to an aspect of the present invention, at least one layer of multilayer film is vapor water barriers film, and it includes below It is a kind of: polyethylene (PE), polypropylene (PP), polyamide, polyethylene terephthalate (PET) or ethylene-vinyl alcohol (EVOH).The grammes per square metre of vapor water barriers film is preferably 10 to 60g/m², preferably 30 to 50g/m².Include micro- fibrillation dialdehyde fiber Polyethylene (PE) layer on at least side of the film of element also improves the compliance of film and provides heat-sealing character.

According to another aspect of the present invention, at least one layer of multilayer film is the barrier layer of metallization." the barrier of metallization Layer " refers to offer barrier property, reduces the infiltrative thin metal layer to such as oxygen gas and water, vapor and light.According to the present invention One aspect, the barrier layer of the metallization is the metal layer or metal oxide layer or chemical gaseous phase of physical vapour deposition (PVD) The metal layer or metal oxide layer of deposition, wherein the metal or metal oxide are selected from aluminium, aluminium oxide, magnesia, oxidation Silicon, copper, magnesium and silicon.Preferably, the weight of the barrier layer of metallization is 50 to 250mg/m², preferably 75 to 150mg/m².The present invention Further relate to packaging material comprising being laminated with previously described includes microfibrillated cellulose and micro- fibrillation dialdehyde cellulose The basic material of at least one layer of the film of mixture.The basic material is preferably Paper or cardboard.One according to the present invention Aspect, the grammes per square metre of the Paper or cardboard of the packaging material are 20 to 500g/m², such as 80 to 400g/m².Packaging material may include Multilayer film also includes one other than the film of the mixture comprising microfibrillated cellulose and micro- fibrillation dialdehyde cellulose A or multiple previously described vapor water barriers layers and/or the barrier layer of metallization.

Detailed description of the invention

Fig. 1: size distribution of two kinds of suspended substances during storage is described；

Fig. 2: the OTR value in fluctuation humidity lower film is described；

Fig. 3: the barrier property of self-supporting (free-standing) film is shown in the form of OTR and WVTR respectively；

Fig. 4: the barrier property of the film through PE coating is shown in the form of OTR and WVTR respectively；With

Fig. 5: the barrier property of LPB structural body is shown in the form of OTR and WVTR respectively

Specific embodiment

It is related to providing the first suspended substance comprising microfibrillated cellulose according to the method for the present invention and is hanged described first Floating body and the second suspended substance comprising micro- fibrillation dialdehyde cellulose (DA-MFC) are mixed to form mixture.Then by mixture It is applied in substrate to form fiber web and then by dry at least one layer to form film of the web.Make us It is surprised to find by forming the microfibrillated cellulose (DA-MFC) comprising microfibrillated cellulose and from dialdehyde cellulose Mixture, realize more stable mixture.Which improve the abilities that processing and mixture form good barrier film.This Outside, discovery can produce at high humidity by using the mixture in the production of at least one layer of film with improved The film of barrier property.Especially, it was surprisingly found that the film has the very good tolerance to the humidity of fluctuation.I.e. Make from low to high, to low and return under high moisture fluctuation, the barrier property of the film is still good.

At least one described layer of film by following production, the mixture is applied to substrate with formed fiber web and The web is dried to form at least one layer of the film.The drying of the web can carry out in any usual manner.Film The dry content of at least one described layer after the drying is preferably higher than 95 weight %.

The method can further comprise after the drying squeeze film the step of.It has shown that if passing through film after the drying The barrier property of the pressure improved, film is improved.Used pressure is preferably 40-900kPa and squeezes sustainable be less than 10 minutes time, preferably 1 second to 10 minutes.Preferably squeezed at elevated temperatures.Used in during extruding Temperature can be 50-200 DEG C, preferably 100-150 DEG C.Extruding can carry out in any conventional equipment, such as press machine or calender. By the way that the extruding (preferably hot extrusion) to film is formed by is used in combination, the barrier property of the film improves significantly.

Substrate can be polymer or metallic substrates, and curtain coating has the mixture thereon.Fiber web through curtain coating coating can It is dry in any convenient manner and subsequently optionally with substrate stripping group bottom.More than one layer can be cast or coated in substrate Form multilayer film.The film for comprising more than a layer can be produced, wherein at least one layer includes mixture according to the present invention.May be used also It may include mixture according to the present invention that energy film, which is more than a layer,.The one or more layers for being also possible to film can be only outstanding comprising first The microfibrillated cellulose of floating body, i.e., itself and do not include micro- fibrillation dialdehyde cellulose (DA-MFC).Be also possible to one of film or Multiple layers are vapor water barriers films, and it includes below any: polyethylene (PE), polypropylene (PP), polyamide, are gathered to benzene two Formic acid glycol ester (PET) or ethylene-vinyl alcohol (EVOH).The one or more layers for being also possible to film are the barrier layers of metallization, It includes any one of aluminium, aluminium oxide, magnesia, silica, copper, magnesium and silicon.Film may include two, three, four, five A, six, seven, eight, nine, ten or more layers.

Substrate can also be the porous silk screen of paper machine, i.e., any kind well known by persons skilled in the art is used to manufacture Paper, cardboard, paper handkerchief or any similar products paper machine.

Substrate can be also basic material, such as Paper or cardboard product, be applied with the mixture thereon to form suitable use Make the coated product of packaging material.Such coated product can be used as suitable for the packaging for retaining liquid contents With the flexible package punch plate of container.The packaging material of layer including mixture according to the present invention can further comprise for preventing sky Gas and water and taste (flavor) migrate across the barrier layer of basic material.According on one side, packaging material may include at least one A vapor water barriers layer, it includes below any: polyethylene (PE), polypropylene (PP), polyamide, poly terephthalic acid second Diol ester (PET) or ethylene-vinyl alcohol (EVOH).Packaging material may also include the barrier layer of one or more metallization, it includes Any one of chlorine, aluminium oxide, magnesia or silica (silicium oxide).

Microfibrillated cellulose in first suspended substance is the micro- fibril produced from mechanical pulp, thermomechanical pulp or chemical pulp Cellulose.The microfibrillated cellulose of first suspended substance is preferably produced from kraft pulp.Micro- fibril chemical fibre of first suspended substance The Schopper Riegler value (SR °) of dimension element is preferably greater than 90.According to another embodiment, the Schopper of MFC Riegler value (SR °) can be greater than 93.According to another embodiment, the Schopper Riegler value (SR °) of MFC can be greater than 95. Schopper-Riegler value can be obtained by standard method defined in EN ISO5267-1.The high SR value is measured to paper pulp , in the case where being with or without extra chemicals, therefore fiber does not consolidate film forming also or starts such as keratinization.It is being decomposed Before measurement SR, the dry solid content of such web is lower than 50% (w/w).It is excellent in order to measure Schopper Riegler value (web consistency is relatively low herein) is selected in after silk screen section to be sampled.Those skilled in the art understand that papermaking chemical product, Such as retention agent or dehydrating agent, have an impact to SR value.SR value illustrated here is interpreted as reflecting the spy of MFC material itself Property instruction rather than limit.

Micro- fibrillation dialdehyde cellulose in second suspended substance should refer to two handled in this way in the present context Aldehyde cellulose, i.e., it is by micro- fibrillation.The production of micro- fibrillation dialdehyde cellulose for example passes through homogenizer or any other modes Processing dialdehyde cellulose carries out generation fibrillation to produce micro- fibrillation dialdehyde cellulose.Micro- original in second suspended substance The preferred degree of oxidation of fibrillation dialdehyde cellulose is 25-75%, preferably 30-65%, even more preferably 30-50% or most more excellent 35-45%.The degree of oxidation according to be described below measurement: after dialdehyde fibrin reaction, measure cellulose in be converted into two The amount of the C2-C3 key of aldehyde.The degree of oxidation is the amount of the C2-C3 key of conversion compared with whole C2-C3 keys.This with H.Zhao and N.D.Heindel's, " Determination of Degree of Substitution of Formyl Groups in Polyaldehyde Dexran by the hydroxylamine hydrochloride Method ", Pharmaceutical Research, volume 8,400-402 pages, 1991 method measurement, wherein available aldehyde group is reacted with hydroxylamine hydrochloride.This is formed Oximido is rolled into a ball and discharges hydrochloric acid.With sodium hydroxide titration hydrochloric acid until reaching pH 4, and then from calculating oxygen according to the following formula The degree of change.Obtained aldehyde obtains the value of the degree of oxidation divided by two, because of the dehydrated glucose unit being oxidized There are two aldehyde radicals for tool.

V_NaOH=need to reach pH 4 sodium hydroxide amount (l)

c_NaOH=0,1mol/l

m_sampleThe dry weight (g) of=DAC sample analyzed

M_w=160g/mol is the molecular weight of dialdehyde cellulose unit

Mixture can further include additive, preferably below any: starch, carboxymethyl cellulose, filler, retention Or mixtures thereof chemicals, coagulation additives, deflocculation additive, dry strength additive, softening agent,.Can add can improve it is mixed Close the additive of different nature of object and/or film produced.It can be to the first suspended substance, the second suspended substance and/or to mixture Add additive.It has shown that using softening agent, such as D-sorbite, glycerol, polyethylene glycol, sorbic acid, propylene glycol, red moss Sugar alcohol, maltitol or polyethylene oxide can change and improve some engineering properties of film, especially break-draw property.Made The amount of D-sorbite is preferably 1-20%, by the dry weight of film.

According to one embodiment, the oxygen of the film comprising microfibrillated cellulose and micro- fibrillation dialdehyde cellulose penetrates Rate is 0.1 to 300cc/m²/ for 24 hours, according to standard ASTM D-3985, under 50% relative humidity at 23 DEG C and/or It is measured at 38 DEG C under 90% relative humidity.

The amount of microfibrillated cellulose in film produced is preferably the 5-80 weight % of the gross dry weight amount of film, preferably The 10-40 weight % of the gross dry weight amount of the 10-60 weight % and even more preferably film of the gross dry weight amount of film.In film produced Micro- fibrillation dialdehyde cellulose amount be preferably film gross dry weight amount 20-95 weight %, the preferably gross dry weight amount of film The 60-90 weight % of the gross dry weight amount of 40-90 weight % and even more preferably film.

According to one embodiment, quantifying for film is smaller than 50g/m², or it is less than 35g/m², or it is less than 25g/m².It is quantitative excellent It is selected as at least 10g/m², preferably 10-50g/m², even more preferably 10-35g/m²And most more excellent 10-25g/m²。

In the context of the present patent application, microfibrillated cellulose (MFC) should mean that at least one dimension is less than 100nm Nanoscale cellulose grain fiber or fibrinogen.MFC includes the cellulose or wood fibre of partially or completely fibrillation Cellulose fiber.The diameter of the fibrinogen of release is less than 100nm, and actual fibrinogen diameter or size distribution and/or aspect ratio are (long Degree/width) depend on source and manufacturing method.The smallest fibrinogen is referred to as basic fibrinogen (elementary fibril dimension) and diameter About 2-4nm is (see, for example, Chinga-Carrasco, G., Cellulose fibres, nanofibrils and microfibrils,:The morphological sequence of MFC components from a plant physiology and fibre technology point of view,Nanoscale research letters 2011,6:417), and commonly aggregated forms basic fibrinogen (it is also defined as microfibril) (Fengel, D., Ultrastructural behavior of cell wall polysaccharides,Tappi J.,March 1970,Vol It 53, No.3.) is the major product obtained when manufacturing MFC, such as by using extended lapping process or pressure drop disintegration process Manufacture.Depending on source and manufacturing method, the length of fibrinogen can change in about 1 to more than 10 micron.Thick MFC grades can contain Considerable fraction of fibrillating fibre, i.e., from the protrusion fibrinogen of tracheid (cellulose fibre) and a certain amount of from tracheid The fibrinogen of (cellulose fibre) release.

MFC has different acronyms, such as cellulose microfibril, fibrillating fibre element, nanometer fibril chemical fibre It is micro- to tie up element, fibrinogen aggregation, nano-grade cellulosic fibrinogen, cellulose nano-fibrous, cellulose nanofibril, cellulose Fiber, cellulose fibril, micro- fibril shape cellulose, microfibril aggregation and cellulose microfibril aggregation.The spy of MFC Sign can also be various physics or physicochemical properties, for example, big surface area or its when being dispersed in water in low solid (1-5 Weight %) under formed gel-like material ability.The preferred fibrillation of cellulose fibre is to such degree, that is, so that being formed The final specific surface area of MFC be about 1 to 200m²/ g or more preferable 50-200m²/ g, with BET method to the material of freeze-drying It is measured.

In the presence of the various methods of manufacture MFC, such as single or multiple fine grindings, prehydrolysis followed by fine grinding or high shear are decomposed Or the release of fibrinogen.One or several pre-treatment steps are usually required, so that MFC manufacture was not only energy saving but also sustainable.Therefore, The cellulose fibre of paper pulp to be supplied can carry out enzyme process or chemical pretreatment, such as so that fiber hydrolysis or swelling or reduction by half The amount of cellulose or lignin.Cellulose fibre can carry out chemical modification before fibrillation, and wherein cellulosic molecule, which contains, removes Except found in the pristine fibre element (or more) functional group.These groups especially include carboxymethyl (CMC), aldehyde And/or carboxyl (passing through the cellulose that the oxidation that N- oxygroup mediates obtains, such as " TEMPO ") or quaternary ammonium (cationic cellulose). After one of being in the above way modified or aoxidizing, it is easier to by fiber hydrolization at MFC or nanometer fibril shape size or NFC.

Nanometer fibril shape cellulose can contain some hemicelluloses；Amount depends on plant origin.Pretreated fiber example As hydrolysis, preswollen or oxidation the machine decomposition of cellulosic material is carried out with suitable equipment, such as refiner, it grinds Machine, homogenizer, colloid discharger (colloider), friction glazed machine, ultrasonic echography instrument, Fluidizer such as microfluidization device, macro See Fluidizer or fluidisation dosage form homogenizer.Depending on MFC manufacturing method, product can also containing particulate or nanocrystal cellulose or Such as the other chemicals present in wood fibre or paper-making process.The product also containing various amounts not by effectively former The fiber grain of the micron-scale of fibrillation.

MFC is prepared by lignocellulose fiber, including both hardwood or cork fibrous.It can also be by microbe-derived, agriculture Industry fiber such as Straw Pulp, bamboo, bagasse or other non-wood sources are made.It is preferably made of paper pulp, including comes from The paper pulp of pristine fibre, for example, mechanical, chemistry and/or thermomechanical pulp.It can also be made of broken or recycled writing paper.

The definition of above-mentioned MFC includes but is not limited to the TAPPI standard newly proposed on cellulose nanofibril (CNF) W13021, defines that containing multiple basic fibrinogens, having high aspect ratio, (width is 5-30nm and aspect ratio is typically larger than 50) cellulose nano-fibrous material has both crystallization and amorphous domain.

In an embodiment of the invention, by microfibrillated cellulose fibril in the presence of wet strength additives Change.This means that wet strength additives are added before fibrillation process or are added during fibrillation process.