WO2012132663A1 - Procédé de production de nanofibres en cellulose - Google Patents

Procédé de production de nanofibres en cellulose Download PDF

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Publication number
WO2012132663A1
WO2012132663A1 PCT/JP2012/054361 JP2012054361W WO2012132663A1 WO 2012132663 A1 WO2012132663 A1 WO 2012132663A1 JP 2012054361 W JP2012054361 W JP 2012054361W WO 2012132663 A1 WO2012132663 A1 WO 2012132663A1
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Prior art keywords
cellulose
raw material
mass
oxidized
dispersion
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PCT/JP2012/054361
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English (en)
Japanese (ja)
Inventor
志穂 辻
宮脇　正一
知章 小柳
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日本製紙株式会社
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Priority to JP2013507274A priority Critical patent/JPWO2012132663A1/ja
Publication of WO2012132663A1 publication Critical patent/WO2012132663A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B15/00—Preparation of other cellulose derivatives or modified cellulose, e.g. complexes
    • C08B15/02—Oxycellulose; Hydrocellulose; Cellulosehydrate, e.g. microcrystalline cellulose
    • C08B15/04—Carboxycellulose, e.g. prepared by oxidation with nitrogen dioxide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/02—Cellulose; Modified cellulose
    • C08L1/04—Oxycellulose; Hydrocellulose, e.g. microcrystalline cellulose
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/04—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides
    • D21C3/16—Pulping cellulose-containing materials with acids, acid salts or acid anhydrides nitrogen oxides; nitric acid nitrates, nitrites
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/18—Pulping cellulose-containing materials with halogens or halogen-generating compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/001—Modification of pulp properties
    • D21C9/002—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives
    • D21C9/005—Modification of pulp properties by chemical means; preparation of dewatered pulp, e.g. in sheet or bulk form, containing special additives organic compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/001—Modification of pulp properties
    • D21C9/007—Modification of pulp properties by mechanical or physical means
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/10—Bleaching ; Apparatus therefor
    • D21C9/12—Bleaching ; Apparatus therefor with halogens or halogen-containing compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
    • D21H11/16—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only modified by a particular after-treatment
    • D21H11/18—Highly hydrated, swollen or fibrillatable fibres
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/14—Polymer mixtures characterised by other features containing polymeric additives characterised by shape
    • C08L2205/16—Fibres; Fibrils

Definitions

  • the present invention relates to a method for producing cellulose nanofibers.
  • this invention relates to the manufacturing method of the cellulose nanofiber which gives the cellulose nanofiber aqueous dispersion of high transparency.
  • TEMPO 2,2,6,6-tetramethyl-1-piperidine-N-oxy radical
  • sodium hypochlorite an inexpensive oxidizing agent sodium hypochlorite
  • Carboxyl groups can be efficiently introduced onto the surface of cellulose microfibrils (oxidation of cellulosic materials). It is known that when this cellulose-based raw material introduced with a carboxyl group is treated in water with a mixer or the like, a highly viscous and transparent cellulose nanofiber aqueous dispersion can be obtained (Non-Patent Document 1, Patent Documents 1 and 2). ).
  • Cellulose nanofiber is a new biodegradable water-dispersed material. Moreover, since the carboxyl group is introduce
  • An object of the present invention is to provide a cellulose nanofiber that gives a highly transparent cellulose nanofiber dispersion.
  • the present inventors have used the above-mentioned cellulose-based raw material derived from hardwood having a hemicellulose content of at least mass% as a cellulose-based raw material to be subjected to an oxidation step using an N-oxyl compound such as TEMPO. I found that the problem could be solved. That is, the said subject is solved by the following this invention.
  • A The presence of a compound selected from the group consisting of (a1) N-oxyl compounds and (a2) bromides, iodides or mixtures thereof, from a broad-leaved tree-derived raw material having a hemicellulose content of 17% by mass or more (A3) a step of oxidizing using an oxidizing agent, and (B) preparing a dispersion having a concentration of the oxidized cellulose-based raw material obtained in the step A of 0.3% (w / v) or more,
  • a method for producing cellulose nanofiber comprising a step of fibrillating and forming nanofibers while dispersing an oxidized cellulose raw material in a dispersion medium.
  • the production method of the present invention comprises (A) a cellulose-based raw material derived from hardwood having a hemicellulose content of 17% by mass or more, (a1) an N-oxyl compound, and (a2) bromide, iodide. Alternatively, in the presence of a compound selected from the group consisting of these mixtures, (a3) the step of oxidizing using an oxidizing agent, and (B) the concentration of the oxidized cellulose-based raw material obtained in step A is 0.3% (W / v) A step of preparing a dispersion liquid as described above and defibrating and dispersing into nanofibers while dispersing the oxidized cellulose raw material in a dispersion medium.
  • step A a cellulosic material derived from hardwood having a hemicellulose content of 17% by mass or more is oxidized under specific conditions.
  • Cellulose-based raw material used in the oxidation step (step A) performed using an N-oxyl compound or the like in the present invention is derived from a broad-leaved tree (hereinafter referred to as a “hard-leaved-derived cellulose-based raw material”) And the hemicellulose content is 17% by mass or more.
  • Hemicellulose is a polysaccharide that constitutes the cell wall of plants, and is a polysaccharide in which an acetyl group or a sugar residue is bonded to the main chain of xylan or glucomannan.
  • the cellulose nanofiber which is excellent in transparency can be manufactured when it is set as a dispersion liquid by using the cellulose raw material derived from hardwood with hemicellulose content of 17 mass% or more. Further, when a hardwood-derived cellulose material having a hemicellulose content of 23% by mass or more, more preferably 25% by mass or more, and further preferably 28% by mass or more is used, a cellulose nanofiber dispersion having excellent transparency can be obtained. It is preferable because not only the amount of carboxyl groups introduced into the cellulose by oxidation increases, but the amount of energy required for defibration (step B) decreases. This mechanism will be described later. Although the upper limit of hemicellulose content of a cellulosic raw material is not limited, Usually, what is necessary is just 30 mass% or less.
  • the hardwood-derived cellulose-based material refers to hardwood-derived pulp, powdered cellulose obtained by pulverizing hardwood-derived pulp with a high-pressure homogenizer, a mill, or the like, or microcrystalline cellulose powder obtained by purifying them by chemical treatment such as acid hydrolysis, etc. .
  • Examples of methods for producing pulp from hardwood include methods for producing mechanical pulp such as ground pulp and thermomechanical pulp, methods for producing chemical pulp such as kraft pulp, sulfite pulp, and organosolv pulp. .
  • methods for producing mechanical pulp such as ground pulp and thermomechanical pulp
  • methods for producing chemical pulp such as kraft pulp, sulfite pulp, and organosolv pulp.
  • Bleaching methods include chlorination (C), chlorine dioxide bleach (D), alkali extraction (E), hypochlorite bleach (H), hydrogen peroxide bleach (P), alkaline hydrogen peroxide treatment stage (Ep ), Alkaline hydrogen peroxide / oxygen treatment stage (Eop), ozone treatment (Z), chelate treatment (Q), and the like.
  • the bleaching treatment may be performed by C / D-EHD, ZEDP, Z / D-Ep-D, Z / D-Ep-DP, D-Ep-D, D- It can be carried out in a sequence such as Ep-DP, D-Ep-PD, Z-Eop-DD, Z / D-Eop-D, Z / D-Eop-DED. “/” In the sequence means that the processes before and after “/” are continuously performed without cleaning.
  • the whiteness (ISO 2470) of the cellulosic raw material (pulp) thus obtained is desirably 80% or more, and more desirably 85% or more.
  • the whiteness of the cellulosic material correlates with the amount of lignin remaining in the pulp.
  • Cellulose-based raw materials with a small amount of lignin that is, a high whiteness, facilitate the introduction of carboxyl groups into the cellulose chain because the oxidation reaction proceeds well in step A, and are easy to disperse in the next step B. This is preferable because cellulose nanofibers that give a high dispersion can be provided.
  • the method for obtaining a broad-leaved cellulosic material having a hemicellulose content of 17% by mass or more is not particularly limited.
  • the ratio of hemicellulose in a raw material falls by the process at the time of manufacturing a chemical pulp, and said bleaching process.
  • the proportion of hemicellulose originally contained varies depending on the species of the broad-leaved tree, and further, the degree of decrease due to the above treatment also varies depending on the species.
  • each condition in the pulping treatment and bleaching treatment (chemical treatment concentration, treatment time, treatment temperature, etc.), it is derived from a broad-leaved tree having a hemicellulose content of 17% by mass or more.
  • the cellulosic material can be obtained.
  • Cellulose-based raw materials derived from broad-leaved trees that can be preferably used in the present invention include, for example, Eucalyptus, Birchula, Begus, Fagus, Acer, Populus , Genus Fraxinus, or hardwood such as Carpinus.
  • Eucalyptus (hereinafter abbreviated as E.) calophylla, E .; citriodora, E .; diversiccolor, E.I. globulus, E.I. grandis, E .; gummifera, E .; marginata, E.M. nesophila, E.I. nitens, E.I.
  • alleghaniensis and the like.
  • Fagus (hereinafter abbreviated as F.), grandifolia, F.M. orientalis, F.M. sylvatica, F.M. Crenata
  • A. maple genus Acer
  • A. camprestre A.M. dasycarpum
  • A.M. ginnal A.M. platanoides
  • A.M. mono A.M. spicatum
  • A. apicatum A.M. saccharinum
  • A.M. rubrum A.R. pseudoplatanus and the like.
  • P. Populus
  • P. Populus
  • P. Populus
  • P. P. maximowiczi
  • P.M. alba P.I. sieboldii
  • P.A. coreana P.M. deltoides
  • P.A. grandidentata P.M. tacamachaca
  • P.M. tremuloids P.M. and trichocarpa.
  • F. genus Fraxinus
  • F. americana
  • F.A. excelsior F.M. mandhurica
  • F.M. pnesylvanica and the like.
  • Examples of the genus Carpinus include C.I. belulus, C.I. cordadata, C.I. japonica, C.I. laxiflora, C.I. tschonoskii, C.I. turczaninovii and the like.
  • the content of hemicellulose contained in the obtained cellulose raw material varies depending on the tree species.
  • the birch genus (Betula) is preferably used in the present invention because it tends to maintain a relatively high hemicellulose content even after pulping or bleaching to obtain a cellulose material with high whiteness.
  • a cellulose-based raw material having a high whiteness and a high hemicellulose content has an advantage that a cellulose nanofiber dispersion having a high transparency can be produced as described above.
  • Most preferred is a cellulosic material having a whiteness of 85% or more and a hemicellulose content of 23% by mass or more.
  • the hemicellulose content of the cellulosic material can be measured as follows. After reacting 300 mg of lyophilized cellulosic raw material in 3 mL of 72 mass% sulfuric acid at room temperature for 2 hours, diluted to a sulfuric acid concentration of 2.5 mass%, and further heated at 105 ° C. for 1 hour, A monosaccharide solution is obtained by an acid hydrolysis reaction. This acid hydrolyzed solution is diluted, and monosaccharides are quantified using ion chromatography (DX-500, manufactured by Dionex, column: AS-7, eluent: water, flow rate 1.1 mL / min).
  • DX-500 ion chromatography
  • Hemicellulose content (mass%) (xylose amount (mg) ⁇ 0.88 + mannose amount (mg) ⁇ 0.9) / cellulose raw material amount (mg) ⁇ 100 (%)
  • N-oxyl compound refers to a compound capable of generating a nitroxy radical.
  • any compound can be used as long as it promotes the target oxidation reaction.
  • the N-oxyl compound used in the present invention includes a compound represented by the following general formula (Formula 1).
  • R 1 to R 4 are the same or different and each represents an alkyl group having about 1 to 4 carbon atoms.
  • TEMPO 2,2,6,6-tetramethyl-1-piperidine-oxy radical
  • the N-oxyl compound represented by any one of the following formulas 2 to 4 that is, the hydroxyl group of 4-hydroxy TEMPO was etherified with alcohol or esterified with carboxylic acid or sulfonic acid to impart moderate hydrophobicity.
  • 4-Acetamide TEMPO which is obtained by acetylating the amino group of 4-hydroxy TEMPO derivative or 4-amino TEMPO represented by the following formula 5 and imparting appropriate hydrophobicity, is inexpensive and provides uniform oxidized cellulose. Is particularly preferable.
  • R is a straight or branched carbon chain having 4 or less carbon atoms.
  • an N-oxyl compound represented by the following formula 6, that is, an azaadamantane type nitroxy radical, is preferable because it can efficiently oxidize a cellulosic raw material in a short time and produce a cellulose nanofiber having a high degree of polymerization.
  • R 5 and R 6 are the same or different and each represents hydrogen or a C 1 -C 6 linear or branched alkyl group.
  • the amount of the N-oxyl compound used is not particularly limited as long as it is a catalyst amount that can promote the oxidation reaction to such an extent that the cellulose raw material can be converted into nanofibers.
  • 0.01 to 10 mmol is preferable, 0.01 to 1 mmol is more preferable, and 0.05 to 0.5 mmol is even more preferable with respect to 1 g of cellulosic raw material.
  • Bromide or iodide refers to a compound containing bromine, examples of which include alkali metal bromides that can dissociate and ionize in water.
  • iodide refers to a compound containing iodine, and examples thereof include alkali metal iodide.
  • the amount of bromide or iodide used can be selected as long as the oxidation reaction can be promoted.
  • the total amount of bromide and iodide is, for example, preferably from 0.1 to 100 mmol, more preferably from 0.1 to 10 mmol, and even more preferably from 0.5 to 5 mmol, based on 1 g of cellulosic raw material.
  • Oxidizing agent (a3) As the oxidizing agent used in the oxidation of the cellulosic raw material, known ones can be used, for example, halogen, hypohalous acid, halous acid, perhalogen acid or salts thereof, halogen oxide, peroxide, etc. Can be used. Among these, from the viewpoint of cost, sodium hypochlorite, which is the most widely used in industrial processes and has a low environmental load, is particularly suitable. In general, broad-leaved cellulosic raw materials are less likely to introduce carboxyl groups (that is, less susceptible to oxidation) than coniferous cellulosic raw materials, so the amount of oxidizing agent used is adjusted to an appropriate range for oxidation.
  • the appropriate amount of the oxidizing agent to be used varies depending on the hardwood species to be used. For example, 0.5 to 500 mmol is preferable, 0.5 to 50 mmol is more preferable, and 0.5 to 50 mmol is more preferable with respect to 1 g of completely dry cellulosic material. 5 to 25 mmol is more preferable, and 5 to 20 mmol is most preferable.
  • the reaction temperature may be a room temperature of about 15 to 30 ° C.
  • a carboxyl group is generated in the cellulose, so that the pH of the reaction solution is reduced.
  • an alkaline solution such as an aqueous sodium hydroxide solution is added to maintain the pH of the reaction solution at about 9 to 12, preferably about 10 to 11.
  • the reaction medium is preferably water because it is easy to handle and hardly causes side reactions.
  • the reaction time in the oxidation reaction can be appropriately set according to the progress of oxidation, and is not particularly limited.
  • the reaction time is 0.5 to 6 hours, preferably 2 to 6 hours, more preferably about 4 to 6 hours. is there.
  • the oxidation reaction may be performed in two stages. For example, oxidized cellulose obtained by filtration after the completion of the first stage reaction is oxidized again under the same or different reaction conditions, so that the cellulose is not subject to reaction inhibition by the salt produced as a by-product in the first stage reaction.
  • the carboxyl group can be efficiently introduced into the system material, and the oxidation of the cellulosic material can be promoted.
  • the amount of carboxyl groups of the oxidized cellulose-based material is 1.0 mmol / g or more with respect to the absolutely dry mass of the oxidized cellulose-based material.
  • the carboxyl group amount is more preferably 1.0 mmol / g to 3.0 mmol / g, further preferably 1.4 mmol / g to 3.0 mmol / g, particularly preferably 1.5 mmol / g to 2.5 mmol. / G.
  • the amount of the carboxyl group can be adjusted by adjusting the oxidation reaction time, adjusting the oxidation reaction temperature, adjusting the pH during the oxidation reaction, adjusting the addition amount of the N-oxyl compound, bromide, iodide, or oxidizing agent.
  • step B it is preferable to wash the oxidized cellulosic material obtained in step A.
  • Step B using the oxidized cellulose-based material obtained in Step A, a dispersion having a concentration of the oxidized cellulose-based material of 0.3% (w / v) or higher is prepared, and the oxidized cellulose-based material is used as a dispersion medium. While being dispersed, it is defibrated into nanofibers. “To make nanofiber” means to process a cellulose-based raw material into cellulose nanofiber which is a single microfibril of cellulose having a width of about 2 to 5 nm and a length of about 1 to 5 ⁇ m.
  • the dispersion of oxidized cellulose material is a liquid in which the oxidized cellulose material is dispersed in a dispersion medium. From the viewpoint of ease of handling, the dispersion medium is preferably water.
  • a strong shearing force is applied to the dispersion using a high-speed rotating type, colloid mill type, high pressure type, roll mill type, ultrasonic type device, etc. Is preferably applied.
  • a wet high-pressure or ultrahigh-pressure homogenizer that can apply a pressure of 50 MPa or more to the dispersion and can apply a strong shearing force.
  • the pressure is more preferably 100 MPa or more, and further preferably 140 MPa or more.
  • the concentration of the oxidized cellulose-based material in the dispersion to be subjected to the treatment is 0.3% (w / v) or more, preferably 1 to 2% (w / v), more preferably 3 to 5% (w / V).
  • the oxidized cellulose raw material obtained in step A (hereinafter simply referred to as “ It is preferable to reduce the viscosity of the “oxidized cellulose raw material”.
  • the viscosity reduction treatment is to appropriately cut the cellulose chain of the oxidized cellulose raw material (shorten the cellulose chain). Since the raw material treated in this way has a low viscosity when used as a dispersion, it can be said that the viscosity reduction treatment is a treatment for obtaining an oxidized cellulose-based raw material that gives a low-viscosity dispersion.
  • the viscosity-reducing treatment may be any treatment that lowers the viscosity of the oxidized cellulose-based material.
  • the treatment of irradiating the oxidized cellulose-based material with ultraviolet rays, the oxidized cellulose-based material with hydrogen peroxide and Examples include a treatment for oxidizing and decomposing with ozone, a treatment for hydrolyzing an oxidized cellulose raw material with an acid, and a combination thereof.
  • the wavelength of the ultraviolet rays is preferably 100 to 400 nm, more preferably 100 to 300 nm.
  • ultraviolet rays having a wavelength of 135 to 260 nm are particularly preferred because they directly act on cellulose and hemicellulose to cause low molecular weight and shorten the oxidized cellulose raw material.
  • a light source capable of irradiating light in a wavelength region of 100 to 400 nm may be used.
  • Specific examples thereof include a xenon short arc lamp, an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a deuterium lamp, a metal halide lamp, and the like, and one or more of these can be used in any combination.
  • ultraviolet rays having different wavelengths can be simultaneously irradiated to increase the number of cellulose chains and hemicellulose chains to be cut, thereby facilitating shortening of the fibers.
  • a container for containing the oxidized cellulosic raw material when performing ultraviolet irradiation for example, when using ultraviolet light having a wavelength longer than 300 nm, a hard glass container can be used, but ultraviolet light having a shorter wavelength than that can be used.
  • a quartz glass container which allows more ultraviolet rays to pass through.
  • a material having little deterioration with respect to the wavelength of the ultraviolet rays may be appropriately selected.
  • the concentration of cellulose nanofibers in the dispersion is preferably 0.1% by mass or more.
  • the concentration is preferably 12% by mass or less in order to improve the fluidity of the oxidized cellulose-based raw material in the ultraviolet irradiation device and increase the reaction efficiency. Accordingly, the concentration is preferably 0.1 to 12% by mass, more preferably 0.5 to 5% by mass, and further preferably 1 to 3% by mass.
  • the reaction temperature is preferably 20 ° C or higher.
  • the reaction temperature is preferably 95 ° C. or lower. Accordingly, the reaction temperature is preferably 20 to 95 ° C, more preferably 20 to 80 ° C, and further preferably 20 to 50 ° C. Further, when the reaction temperature is within this range, there is an advantage that it is not necessary to design an apparatus in consideration of pressure resistance.
  • the pH of the system in the reaction is not limited, but in view of simplification of the process, a neutral region, for example, about pH 6.0 to 8.0 is preferable.
  • the degree of ultraviolet irradiation can be arbitrarily set by adjusting the residence time of the oxidized cellulose raw material in the irradiation reaction apparatus or the energy amount of the irradiation light source. Also, for example, by diluting the concentration of the oxidized cellulose raw material dispersion in the irradiation apparatus with water or the like, or by blowing and diluting with an inert gas such as air or nitrogen, the amount of ultraviolet radiation received by the oxidized cellulose raw material can be reduced. Can be adjusted. These conditions are appropriately selected so that the quality (fiber length, degree of cellulose polymerization, etc.) of the oxidized cellulose-based raw material after treatment is set to a desired value.
  • the ultraviolet irradiation treatment is carried out in the presence of an auxiliary agent such as oxygen, ozone, or peroxide (hydrogen peroxide, peracetic acid, sodium percarbonate, sodium perborate, etc.), the efficiency of the photooxidation reaction is further improved. Since it can raise, it is preferable.
  • an auxiliary agent such as oxygen, ozone, or peroxide (hydrogen peroxide, peracetic acid, sodium percarbonate, sodium perborate, etc.)
  • ozone is generated from oxygen in the air normally present in the gas phase around the light source, and this ozone is preferably used as an auxiliary agent.
  • the ozone generated by continuously supplying air to the periphery of the light source is continuously extracted, and the ozone extracted from outside the system is injected into the oxidized cellulosic raw material.
  • ozone can be used as an auxiliary for the photo-oxidation reaction.
  • a larger amount of ozone can be generated in the system by supplying oxygen to the gas phase around the light source.
  • ozone that is secondarily generated in the ultraviolet irradiation reactor can be used.
  • the ultraviolet irradiation treatment can be repeated multiple times.
  • the number of repetitions can be appropriately set according to the relationship with the quality of the oxidized cellulose-based raw material after the treatment and the post-treatment such as bleaching.
  • ultraviolet rays of 100 to 400 nm, preferably 135 to 260 nm can be irradiated 1 to 10 times, preferably 2 to 5 times.
  • the irradiation time per time is preferably 0.5 to 10 hours, and more preferably 0.5 to 3 hours.
  • Oxidative decomposition with hydrogen peroxide and ozone Ozone used in the treatment can be generated by a known method using an ozone generator using air or oxygen as a raw material.
  • a dispersion obtained by dispersing an oxidized cellulose-based material in a dispersion medium such as water for the reaction it is preferable to use a dispersion obtained by dispersing an oxidized cellulose-based material in a dispersion medium such as water for the reaction.
  • the amount (mass) of ozone used in the present invention is preferably 0.1 to 3 times the absolute dry mass of the oxidized cellulose raw material.
  • the amount of ozone used is at least 0.1 times the absolute dry mass of the oxidized cellulose raw material, the amorphous part of cellulose can be sufficiently decomposed, and the energy required for the defibration / dispersion treatment in the next step B Can be greatly reduced.
  • the amount of ozone used is more preferably 0.3 to 2.5 times, and even more preferably 0.5 to 1.5 times the absolute dry mass of the oxidized cellulose raw material.
  • the amount (mass) of hydrogen peroxide used is preferably 0.001 to 1.5 times the absolute dry mass of the oxidized cellulose material.
  • hydrogen peroxide is used in an amount 0.001 times or more that of the oxidized cellulose raw material, a synergistic action between ozone and hydrogen peroxide occurs, and an efficient reaction becomes possible.
  • the amount of hydrogen peroxide used is more preferably 0.1 to 1.0 times the absolute dry mass of the oxidized cellulose raw material.
  • the pH of the system in the oxidative decomposition treatment with ozone and hydrogen peroxide is preferably 2 to 12, more preferably pH 4 to 10, and further preferably pH 6 to 8.
  • the temperature is preferably 10 to 90 ° C, more preferably 20 to 70 ° C, and further preferably 30 to 50 ° C.
  • the treatment time is preferably 1 to 20 hours, more preferably 2 to 10 hours, and further preferably 3 to 6 hours.
  • a device for performing treatment with ozone and hydrogen peroxide a commonly used device can be used. Examples include a conventional reactor with a reaction chamber, a stirrer, a chemical injector, a heater, and a pH electrode.
  • ozone and hydrogen peroxide remaining in the aqueous solution effectively work even in the defibration treatment of the next step B, so that cellulose nanofibers that give a dispersion with a lower viscosity can be produced.
  • an acid is added to the oxidized cellulose raw material to hydrolyze the cellulose chain (acid hydrolysis treatment).
  • the acid it is preferable to use a mineral acid such as sulfuric acid, hydrochloric acid, nitric acid, or phosphoric acid.
  • a dispersion liquid in which an oxidized cellulose-based raw material is dispersed in a dispersion medium such as water.
  • the conditions for the acid hydrolysis treatment may be any conditions that allow the acid to act on the amorphous part of the cellulose.
  • the amount of acid added is preferably 0.01 to 0.5% by mass, more preferably 0.1 to 0.5% by mass, based on the absolutely dry mass of the oxidized cellulose raw material. It is preferable for the amount of acid added to be 0.01% by mass or more because hydrolysis of cellulose proceeds and the processing efficiency in the next step B is improved. Moreover, the excessive hydrolysis of a cellulose can be prevented as the said addition amount is 0.5 mass% or less, and the fall of the yield of a cellulose nanofiber can be prevented.
  • the pH of the system during acid hydrolysis is preferably from 2.0 to 4.0, more preferably from 2.0 to less than 3.0. From the viewpoint of acid hydrolysis efficiency, the reaction is preferably carried out at a temperature of 70 to 120 ° C. for 1 to 10 hours.
  • the reason why the reduced viscosity of the oxidized cellulose raw material can be efficiently carried out by the acid hydrolysis treatment is presumed as follows. As described above, the carboxyl group is localized on the surface of the cellulosic raw material oxidized with the N-oxyl compound, a hydration layer is formed, and the raw materials are close to each other to form a network. ing. When an acid is added to the raw material and hydrolysis is performed, the balance of charges in the network is lost, the strong network of cellulose molecules is lost, the specific surface area of the raw material is increased, and the oxidized cellulose raw material is shortened. Is promoted, and the viscosity of the cellulosic material is reduced.
  • the cellulose nanofibers obtained by the production method of the present invention are cellulose single microfibrils having a width of 2 to 5 nm and a length of about 1 to 5 ⁇ m.
  • the dispersion of cellulose nanofibers obtained by the present invention has excellent transparency.
  • the dispersion medium in the dispersion is preferably water.
  • the transparency is evaluated by the transmittance of light having a wavelength of 660 nm. Specifically, using a UV / visible spectrophotometer, a 0.1% (v / w) dispersion in a quartz cell (optical path 10 mm). It is calculated
  • the aqueous dispersion of cellulose nanofibers obtained by the present invention has a light transmittance of 660 nm at a concentration of 0.1% (w / v), preferably 94% or more, more preferably 95% or more. Preferably it is 97% or more, particularly preferably 99% or more.
  • the transparency is 95% or more, it can be used without problems for general film applications, and when the transparency is 99% or more, high optical properties (transparency) such as a display and a touch panel are required. Can be used without problems for film applications.
  • the cellulose-based raw material derived from hardwood is considered to be superior as a raw material for cellulose nanofiber because the fibers are thinner and shorter than the cellulose-based raw material derived from conifer.
  • cellulosic materials have hemicellulose between cellulose microfibrils. If hemicellulose is present between cellulose microfibrils, it is considered that voids are formed between cellulose microfibrils because hemicellulose is eluted during an oxidation reaction under alkaline conditions. Thereby, it is estimated that the catalyst easily reaches the surface of the cellulose microfibril, and the primary hydroxyl group on the surface of the cellulose microfibril is selectively oxidized.
  • the amount of carboxyl groups of the cellulose nanofibers produced according to the present invention is preferably 1.2 mmol / g or more, more preferably 1.7 mmol / g or more, and further preferably 1.8 mmol / g or more.
  • Such a cellulose nanofiber having a carboxyl group can form a sheet excellent in barrier properties and heat resistance. Therefore, the cellulose nanofiber manufactured by this invention can be used for various uses, such as a packaging material.
  • Example 2 P. is a hardwood.
  • a cellulose nanofiber aqueous dispersion was produced and evaluated in the same manner as in Example 1 except that bleached unbeaten kraft pulp derived from alba (having a hemicellulose content of 17.9% by mass and a whiteness of 86%) was used.
  • Example 3 Both are hardwoods. Crenata and C.I. Cellulose nanofibers in the same manner as in Example 1 except that bleached unbeaten kraft pulp (hemicellulose content 22.1% by mass, whiteness 84%) derived from a mixture with belulus (mixing ratio 50:50) was used. An aqueous dispersion was produced and evaluated.
  • Example 4 B. a hardwood. A cellulose nanofiber aqueous dispersion was produced and evaluated in the same manner as in Example 1 except that bleached unbeaten kraft pulp derived from pendula (hemicellulose content: 23.3 mass%, whiteness: 86%) was used.
  • Example 5 B. a hardwood.
  • a cellulose nanofiber aqueous dispersion was produced and evaluated in the same manner as in Example 1 except that bleached unbeaten kraft pulp derived from verrucosa (having a hemicellulose content of 25.6% by mass and a whiteness of 86%) was used.
  • Example 1 R. hardwood. A cellulose nanofiber aqueous dispersion was produced and evaluated in the same manner as in Example 1 except that bleached unbeaten kraft pulp derived from pseudoacacia (having a hemicellulose content of 16.7% by mass and a whiteness of 85%) was used.
  • Example 2 Hardwood A cellulose nanofiber aqueous dispersion was produced and evaluated in the same manner as in Example 1 except that bleached unbeaten kraft pulp derived from Mangiumu (hemicellulose content 12.3 mass%, whiteness 86%) was used.
  • Example using the cellulosic raw material derived from hardwood having a hemicellulose content of 17% by mass or more is more transparent than the comparative example using the cellulosic raw material having a hemicellulose content of less than 17% by mass. It can be seen that cellulose nanofibers that give a high aqueous dispersion can be produced.

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Abstract

Cette invention concerne des nanofibres en cellulose qui sont produites par un procédé impliquant une étape (A) d'oxydation d'un matériau de départ cellulosique dérivé d'un bois dur ayant une teneur en hémicellulose de 17 % en poids ou plus à l'aide d'un agent d'oxydation (a3) en présence d'un composé de N-oxyle (a1) et d'un composé (a2) choisi parmi le brome, l'iode et leur mélange, et une étape (B) de préparation d'un liquide de dispersion ayant une concentration de matériau de départ cellulosique oxydé obtenu à l'étape (A) de 0,3 % (p/v) ou plus et de conversion dudit matériau de départ cellulosique oxydé en nanofibres par fibrillation du matériau de départ cellulosique oxydé pendant sa dispersion dans un milieu de dispersion.
PCT/JP2012/054361 2011-03-30 2012-02-23 Procédé de production de nanofibres en cellulose WO2012132663A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10731298B2 (en) 2012-06-15 2020-08-04 University Of Maine System Board Of Trustees Release paper and method of manufacture
WO2021145291A1 (fr) * 2020-01-16 2021-07-22 東亞合成株式会社 Procédés de production d'oxyde de cellulose et de nanofibres de cellulose, oxyde de cellulose, nanofibre de cellulose et produits alimentaires

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008308802A (ja) * 2007-06-18 2008-12-25 Univ Of Tokyo セルロースナノファイバーの製造方法
WO2009069641A1 (fr) * 2007-11-26 2009-06-04 The University Of Tokyo Nanofibre de cellulose et son procédé de fabrication, et dispersion de nanofibre de cellulose
JP2009161613A (ja) * 2007-12-28 2009-07-23 Nippon Paper Industries Co Ltd セルロースの酸化方法、セルロースの酸化触媒及びセルロースナノファイバーの製造方法
JP2009173909A (ja) * 2007-12-28 2009-08-06 Nippon Paper Industries Co Ltd セルロースナノファイバーの製造方法及びセルロースの酸化触媒
WO2009107795A1 (fr) * 2008-02-29 2009-09-03 国立大学法人東京大学 Procédé de modification de cellulose, cellulose modifiée, acide celluronique et microcristal de cellulose
WO2009122982A1 (fr) * 2008-03-31 2009-10-08 日本製紙株式会社 Additif destiné à la fabrication du papier et papier contenant cet additif

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008308802A (ja) * 2007-06-18 2008-12-25 Univ Of Tokyo セルロースナノファイバーの製造方法
WO2009069641A1 (fr) * 2007-11-26 2009-06-04 The University Of Tokyo Nanofibre de cellulose et son procédé de fabrication, et dispersion de nanofibre de cellulose
JP2009161613A (ja) * 2007-12-28 2009-07-23 Nippon Paper Industries Co Ltd セルロースの酸化方法、セルロースの酸化触媒及びセルロースナノファイバーの製造方法
JP2009173909A (ja) * 2007-12-28 2009-08-06 Nippon Paper Industries Co Ltd セルロースナノファイバーの製造方法及びセルロースの酸化触媒
WO2009107795A1 (fr) * 2008-02-29 2009-09-03 国立大学法人東京大学 Procédé de modification de cellulose, cellulose modifiée, acide celluronique et microcristal de cellulose
WO2009122982A1 (fr) * 2008-03-31 2009-10-08 日本製紙株式会社 Additif destiné à la fabrication du papier et papier contenant cet additif

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ISKANDER BESBES ET AL.: "Nanofibrillated cellulose from TEMPO-oxidized eucalyptus fibres: Effect of the carboxyl content", CARBOHYDRATE POLYMERS, vol. 84, no. 3, 17 March 2011 (2011-03-17), pages 975 - 983, XP028365154, DOI: doi:10.1016/j.carbpol.2010.12.052 *
SHINICHIRO IWAMOTO ET AL.: "The Effect of Hemicelluloses on Wood Pulp Nanofibrillation and Nanofiber Network Characteristics", BIOMACROMOLECULES, vol. 9, 2008, pages 1022 - 1026 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10731298B2 (en) 2012-06-15 2020-08-04 University Of Maine System Board Of Trustees Release paper and method of manufacture
WO2021145291A1 (fr) * 2020-01-16 2021-07-22 東亞合成株式会社 Procédés de production d'oxyde de cellulose et de nanofibres de cellulose, oxyde de cellulose, nanofibre de cellulose et produits alimentaires

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