JP5735833B2 - Method for producing cellulose - Google Patents

Description

  The present invention relates to a method for producing cellulose (particularly, fibrous cellulose) from cellulose-containing components (cellulose-containing components including non-crystalline components such as cellulose and lignocellulose), and crystalline cellulose (cellulose fibers) obtained by this method. And a resin composition containing the cellulose. The present invention also relates to an extractant for producing crystalline cellulose by separating an amorphous component (such as lignin component) from a cellulose-containing component (such as lignocellulose) containing an amorphous component.

  Cellulose is synthesized on earth at a rate of about 400 billion tons per year and is the most abundant biomass. Such cellulose is partly produced by microorganisms, but most of cellulose is produced by higher plants such as trees.

  In cellulose derived from plants, the molecular chains of cellulose are oriented and converged in the process of biosynthesis, and first, very thin highly crystalline fibers called microfibrils are formed. Further, these microfibrils are bundled to form a higher-order structure step by step with the fibrils, lamellae, and fiber cells. The microfibril usually has a diameter of several nanometers to several tens of nanometers, and its length is several hundred nanometers to several tens of microns, depending on the production method. Cellulose molecular chains that make up this microfibril are extended chain crystals, so properties such as elastic modulus, strength, and thermal expansion coefficient are comparable to magnesium alloys, while low specific gravity, high aspect, large surface area, etc. In recent years, it has attracted attention as a resin reinforcing material. In addition, such cellulose is expected to be expanded more than ever by taking advantage of environmentally friendly characteristics and the use of recycled resources.

  However, in plants, lignin, hemicellulose, and amorphous cellulose are present between the cellulose fibers that constitute the fiber cells of the plant in stages from microfibrils to fibrils, lamellae, etc. Cellulose fiber is strongly bonded as. Therefore, it is very difficult to separate and extract cellulose fibers from plants.

  Many proposals have been made for a method for producing such a cellulose fiber. As a conventional method, there is known a method for fibrillating a fiber by subjecting a cellulose fiber raw material to a beating process or a homogenizing process.

  However, in order to obtain a cellulose fiber having a small fiber diameter, it is necessary to sufficiently perform the beating process. As a result, the fiber may be greatly damaged, and the strength and aspect ratio of the obtained cellulose fiber may be reduced. There is. On the other hand, if the beating treatment is reduced to suppress the fiber damage, the obtained fiber has a large fiber diameter and a small aspect ratio, so that a cellulose fiber having good reinforcing properties cannot be obtained. In addition, a method of beating after hydrolyzing with an acid such as hydrochloric acid is also known, but in such a method, cellulose fibers can be easily separated by acid treatment, so finer fibers can be obtained. However, there is a possibility that the cellulose nanofiber is damaged and the physical properties of the cellulose fiber are lowered.

  In addition, the conventional beating process and homogenizing process often require a plurality of processes to be performed, resulting in low production efficiency.

  On the other hand, in recent years, a technique for dissolving cellulose in an ionic liquid (such as an imidazole salt) has been developed. For example, in JP 2009-203467 A (Patent Document 1), a solvent composed of an ionic liquid and a nitrogen-based organic solvent or dimethyl sulfoxide dissolves cellulose, and a cellulose solution dissolved in such a solvent is extracted. It is disclosed that cellulose fibers can be obtained by passage through an agent (or coagulant such as water, acetone, methanol, etc.).

  JP 2009-189277 A (Patent Document 2) includes a step of dissolving mainly woody biomass-derived cellulose and / or hemicellulose in an ionic liquid by mixing woody biomass into an ionic liquid; A method for treating woody biomass including a step of separating residual components (such as lignin) from a liquid is disclosed.

  However, in such a method using an ionic liquid, in order to obtain a fiber by partially dissolving cellulose, it is necessary to use an ionic liquid that is unknown in terms of safety. Furthermore, a complicated process is required to completely wash and remove the ionic liquid which is a good solvent for cellulose.

JP 2009-203467 A (Claims) JP 2009-189277 A (Claims)

  Therefore, an object of the present invention is to easily and efficiently produce cellulose (in particular, fibrous cellulose such as cellulose nanofiber) from a cellulose-containing component (for example, a cellulose-containing component including an amorphous component), and this It is in providing the cellulose (especially cellulose fiber) obtained by a method.

  Another object of the present invention is a method for producing high-quality cellulose (or cellulose fiber) that does not require special treatment such as beating treatment and causes little damage to the fiber, and cellulose (or cellulose fiber) obtained by this method. ) To provide.

  Still another object of the present invention is to provide a resin composition containing high-quality cellulose (or cellulose fiber) or a derivative thereof (for example, cellulose ester fiber such as cellulose acetate fiber) obtained by the above method, and a cured product thereof. There is.

  Still another object of the present invention is to provide an extractant capable of efficiently extracting an amorphous component such as lignin from a cellulose-containing component such as lignocellulose.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that a compound having a fluorene skeleton (specifically, a 9,9-bisarylfluorene skeleton) and a cellulose-containing component (for example, a cellulose-containing component containing an amorphous component) Component), the compound having a fluorene skeleton penetrates into the cellulose structure (cellulose structure, cellulose fiber aggregate) and relaxes, or cellulose (crystalline cellulose, cellulose fiber) is not decomposed, The non-crystalline component in the cellulose-containing component can be easily extracted (or the cellulose fiber aggregate is relaxed) to obtain cellulose (fibrous cellulose). In particular, as the cellulose-containing component, non-crystalline such as lignocellulose Using cellulose-containing ingredients including ingredients (lignin, hemicellulose, etc.) In addition, it has been found that a non-crystalline component can be selectively solubilized or extracted from a cellulose-containing component by a compound having a fluorene skeleton, and a high-quality cellulose fiber having high crystallinity can be obtained efficiently. completed.

  In other words, the production method of the present invention comprises cellulose-containing components [or cellulose raw materials such as cellulose-containing components (such as lignocellulose) containing cellulose and amorphous components (or impurities) and cellulose (cellulose fiber aggregates). Of cellulose (especially, 80% by weight or more, preferably 90% by weight or more) containing cellulose (especially cellulose fibers or fibrous cellulose) from a cellulose-containing component (or a non-crystalline component from a cellulose-containing component). A method for producing cellulose by separating and removing, or a method for producing a cellulose fiber by relaxing a cellulose fiber aggregate in a cellulose-containing component), comprising a cellulose-containing component and a compound having a 9,9-bisarylfluorene skeleton; The mixing step of mixing the mixture obtained through this step From the object, and a separation step of separating the compound having at least 9,9-bisaryl fluorene skeleton. Usually, a cellulose-containing component (for example, a cellulose-containing component including an amorphous component) contains cellulose (or a cellulose fiber aggregate or a fibrous cellulose aggregate) in a fibrous form. Therefore, in the method of the present invention, the cellulose form in the cellulose-containing component is usually reflected, that is, at least fibrous cellulose may be obtained. Normally, at least fiber-like cellulose is obtained in this way, but the fiber-like cellulose is further processed (for example, pulverized) to obtain a desired shape or form of cellulose (for example, granular cellulose). You can also get

  In the method of the present invention, the compound having the 9,9-bisarylfluorene skeleton may be, for example, a compound represented by the following formula (1).

(In the formula, ring Z represents an aromatic hydrocarbon ring, R ¹ represents a substituent, X represents a heteroatom-containing functional group (such as a hydroxyl group), R ² represents an alkylene group, and R ³ represents a substituted group. Represents a group, k is an integer of 0 to 4, m is an integer of 0 or more, n is an integer of 1 or more, and p is an integer of 0 or more.)
In the mixing step, the cellulose-containing component and the compound having the 9,9-bisarylfluorene skeleton may be mixed, for example, at a ratio of the former / the latter (weight ratio) = 85/15 to 5/95. . Moreover, in the said mixing process, you may mix under heating (for example, under 160-300 degreeC heating).

  In the method, typically, the cellulose-containing component is lignocellulose, and the non-crystalline component containing lignin is solubilized or extracted from the lignocellulose by the compound having the 9,9-bisarylfluorene skeleton in the mixing step. In the separation step, the non-crystalline component (or the extracted non-crystalline component) may be separated together with the compound having a 9,9-bisarylfluorene skeleton.

  In the method of the present invention, not only the cellulose-containing component containing a relatively large amount of amorphous component (or impurities) such as lignocellulose, but also the proportion of the cellulose content (or cellulose fiber aggregate) is relatively high, A cellulose-containing component mainly composed of cellulose can also be used. That is, as described above, such a cellulose-containing component is treated with a compound having a 9,9-bisarylfluorene skeleton, whereby the cellulose fiber assembly constituting the cellulose-containing component is relaxed (or fiber). Impurities between fibers in the aggregate are extracted), and cellulose fibers are obtained. Therefore, in the said method, a cellulose fiber (especially cellulose nanofiber) is manufactured using the cellulose containing component which contains a cellulose (or cellulose fiber aggregate) in a high ratio (for example, the ratio of 80 weight% or more). Also good.

  The method of the present invention may further include a defibrating step of defibrating cellulose (fibrous cellulose) obtained through the separation step.

  The present invention also includes a fibrous cellulose (cellulose fiber) obtained by the production method. Such a cellulose fiber may contain a compound having a 9,9-bisarylfluorene skeleton. Moreover, the cellulose fiber may contain the non-crystalline component and / or its decomposition product. As described above, the compound having a 9,9-bisarylfluorene skeleton and the non-crystalline component are separated in the separation step. However, when a part of the compound is contained in the crystalline cellulose, the hydrophobicity of the crystalline cellulose is increased. And heat resistance, and further, dispersibility with respect to the resin can be improved.

  The present invention also includes a resin composition containing a resin and the fibrous cellulose (or cellulose fiber) or a derivative thereof (for example, cellulose ester such as cellulose acetate). In particular, since the cellulose fiber or derivative thereof is excellent in dispersibility with respect to a compound having a 9,9-bisarylfluorene skeleton, the resin may be a resin having a 9,9-bisarylfluorene skeleton. Furthermore, the present invention includes a thermosetting resin (for example, a thermosetting resin having a 9,9-bilarylfluorene skeleton) and the fibrous cellulose or a derivative thereof (cellulose fiber or cellulose derivative fiber). A cured product obtained by curing the resin composition is also included.

  The compound having the 9,9-bisfluorene skeleton can efficiently extract such an amorphous component even if the cellulose-containing component contains an amorphous component. Therefore, in the present invention, a cellulose (for example, fibrous cellulose) is obtained by extracting an amorphous component from a cellulose-containing component including crystalline cellulose and an amorphous component (lignin, hemicellulose, amorphous cellulose, etc.). And an extractant composed of a compound having a 9,9-bisarylfluorene skeleton.

  In the method of the present invention, cellulose (in particular, a fiber shape such as cellulose nanofiber) can be easily and efficiently simply by mixing a cellulose-containing component (for example, a cellulose-containing component including an amorphous component) and a compound having a fluorene skeleton. Cellulose). That is, a compound having a 9,9-bisarylfluorene skeleton penetrates between cellulose fiber assemblies constituting the cellulose-containing component, weakening strong bonds (hydrogen bonds) between the fiber assemblies, or between the fiber assemblies. Cellulose fibers (particularly cellulose nanofibers) can be obtained efficiently because of the extraction of the impurities. In particular, in the method of the present invention, even when a cellulose-containing component containing an amorphous component such as lignin or hemicellulose is used as a cellulose source, the amorphous component can be selectively solubilized or extracted from the cellulose-containing component, and cellulose (cellulose fiber) is obtained. Can be manufactured efficiently. Moreover, such a method does not require a special treatment such as a beating treatment, and can obtain high-quality crystalline cellulose (or cellulose fiber) with little damage to the fibers. Furthermore, in this invention, the resin composition containing the high quality cellulose (or cellulose fiber) obtained by the said method or its derivative (s) (for example, cellulose ester fiber etc.) and its hardened | cured material can be provided. In such a resin composition or cured product, crystalline cellulose (cellulose fiber) or a derivative thereof is dispersed with high dispersibility, and is excellent in heat resistance, strength, and the like. Furthermore, the extractant of the present invention can efficiently extract amorphous components such as lignin from cellulose-containing components such as lignocellulose.

FIG. 1 is an SEM photograph of the film obtained in Example 1. FIG. 2 is an SEM photograph of the film obtained in Example 2. FIG. 3 is an SEM photograph of the film obtained in Comparative Example 1. FIG. 4 is an SEM photograph of the film obtained in Example 6. FIG. 5 is a photograph of the film obtained in Example 7.

[Method for producing cellulose fiber]
In the method of the present invention, using a compound having a 9,9-bisarylfluorene skeleton (sometimes simply referred to as a compound having a fluorene skeleton), a cellulose-containing component (for example, cellulose (or cellulose fiber aggregate)) and Cellulose (or cellulose or cellulose fiber from which the amorphous component has been removed) is produced from the cellulose-containing component including the amorphous component. Such a method usually involves mixing a cellulose-containing component and a compound having a 9,9-bisarylfluorene skeleton (usually heating and mixing), and a mixture obtained through this step from 9,9- Separating the compound having a bisarylfluorene skeleton. In such a method, fiber-like cellulose (or cellulose in the form of fibers) is usually obtained.

(Cellulose-containing component)
The cellulose-containing component only needs to contain cellulose (or a fiber aggregate of cellulose or crystalline cellulose), and may contain cellulose (or crystalline cellulose) and an amorphous component. The cellulose-containing component may contain cellulose (crystalline cellulose) in the form of an aggregate (or aggregate) of cellulose fibers (cellulose microfibrils). The fiber diameter (secondary fiber diameter) of such an aggregate or aggregate may be, for example, on the order of micrometers (for example, 1 to 100 μm, preferably 3 to 50 μm, more preferably about 5 to 30 μm). . In the present invention, by relaxing (or loosening) such a fiber assembly, nanometer-order cellulose fibers (that is, cellulose nanofibers) can be obtained as described later.

  Examples of the amorphous component include lignin, hemicellulose, amorphous cellulose (or amorphous cellulose), and the like. In particular, the cellulose-containing component (cellulose-containing component including an amorphous component) may be lignocellulose (lignin-containing cellulose). In the present invention, since the cellulose skeleton can be relaxed while selectively solubilizing or extracting the non-crystalline component, cellulose (cellulose fiber) can be efficiently used even with a cellulose-containing component containing such non-crystalline component. Can be obtained. By using a cellulose-containing component containing such an amorphous component, crystalline cellulose can be obtained as it is from wood without using cellulose (such as microcrystalline cellulose). Is extremely cost effective.

  Lignocellulose is composed of cellulose and lignin. Lignin is an amorphous polymer existing as a plant vascular cell wall component, and is a condensate containing a phenylpropane-based structural unit. Examples of such lignocellulose (substance containing lignin) include wood and herbs. Wood is roughly classified into conifers and broad-leaved trees, and examples of conifers include pine, cedar, cypress, yew, and inugaya. Examples of broad-leaved trees include shii, cherry blossoms and firewood. Examples of herbs include kenaf, straw, bagasse, flax, manila hemp, jute and cocoon. Lignin contained in conifers (conifer lignin) may have a guaiacylpropane structure, and lignin contained in broadleaf trees (broadleaf lignin) may have a guaiacylpropane structure and a syringylpropane structure. The lignin (herbaceous lignin) contained in herbs may have a guaiacylpropane structure, a syringylpropane structure, and a p-hydroxyphenylpropane structure. The methoxy group content may be about 14 to 17% by weight for softwood lignin, about 20 to 23% by weight for hardwood lignin, and about 14 to 15% by weight for herbaceous lignin.

  The timber may be thinned wood or the like, and may be used in the form of crushed wood, for example, wood flour, wood chips, veneer scrap, etc., and waste materials (such as building waste materials) may be used.

  As the cellulose-containing component, pulp (for example, wood pulp, bamboo pulp, walla pulp, bagasse pulp, cotton pulp, flax pulp, hemp pulp, straw pulp, three straw pulp, cotton pulp, etc.) can also be used. Furthermore, as lignocellulose, pulp-containing molded products such as paper (papermaking, board, etc.) prepared from pulp and waste paper can also be used. In the pulp, depending on the production method, most of the lignin and hemicellulose may be removed. However, even in such a pulp, the amorphous cellulose usually remains, and this amorphous cellulose (or amorphous) Cellulose) exists between cellulose (crystalline cellulose) and is firmly bonded.

  As a typical cellulose-containing component (lignocellulose), for example, wood (for example, at least one selected from coniferous trees and hardwoods), herbs, pulp, pulp-containing molded bodies, and the like can be used. Lignocellulose may be used alone or in combination of two or more.

  In addition, when waste materials such as wood flour (such as building waste materials) are reused, lignocellulose can be used effectively. The size of the lignocellulose crushed material (wood powder, etc.) is not particularly limited, but for efficient production, the average diameter is 0.01 to 1 mm, preferably 0.02 to 0.5 mm, more preferably 0.03. It may be about 0.1 mm.

  In the present invention, as the cellulose-containing component, a cellulose-containing component containing cellulose as a main component [or cellulose from which most of the amorphous component (lignin or hemicellulose) has been removed] may be used. Such a cellulose-containing component is not particularly limited, and examples thereof include pulp (especially chemical pulp) and microcrystalline cellulose.

  In the cellulose-containing component (cellulose-containing component including the non-crystalline component), the proportion of the non-crystalline component (for example, lignin, hemicellulose, non-crystalline cellulose, etc.) depends on the type, for example, 1 to 90% by weight, preferably May be about 3 to 80% by weight, more preferably about 5 to 70% by weight. In particular, in the pulp, the proportion of amorphous components (such as amorphous cellulose) may be 1 to 40% by weight, preferably 1.5 to 30% by weight, and more preferably about 2 to 25% by weight.

  In the cellulose-containing component containing cellulose as a main component, the ratio of the amorphous component (or impurity) is, for example, 20% by weight or less (for example, 0.01 to 15% by weight), preferably 10% of the whole cellulose-containing component. It may be 5% by weight or less (for example, 0.05 to 7% by weight), more preferably 5% by weight or less (for example, 0.1 to 3% by weight).

  In particular, in lignocellulose, the ratio of cellulose to lignin is not particularly limited. For example, the former / the latter (weight ratio) = 99/1 to 20/80, preferably 95/5 to 30/70, more preferably. It may be about 90/10 to 40/60. In lignocellulose, the ratio of lignin may be, for example, about 1 to 50% by weight, preferably about 5 to 45% by weight, and more preferably about 5 to 40% by weight.

  Lignocellulose contains lignin as an amorphous component, but it may usually contain hemicellulose or amorphous cellulose in addition to lignin. In the present invention, not only lignin but also hemicellulose and the like are solubilized or dissolved by the compound having a fluorene skeleton, and can be efficiently separated from the cellulose-containing component.

  In lignocellulose, the ratio of cellulose to hemicellulose is the former / the latter (weight ratio) = 99/1 to 20/80, preferably 95/5 to 30/70, more preferably about 90/10 to 40/60. There may be. In lignocellulose, the proportion of hemicellulose may be, for example, about 1 to 50% by weight, preferably about 5 to 45% by weight, and more preferably about 10 to 40% by weight.

  In lignocellulose, the proportion of amorphous components (for example, lignin and hemicellulose) is 5 to 90% by weight, preferably 10 to 80% by weight, more preferably 20 to 70% by weight, especially about 30 to 60% by weight. It may be.

  In the cellulose-containing component, the cellulose content is, for example, about 30% by weight or more (for example, 30 to 99.9% by weight), preferably about 35% by weight or more (for example, 38 to 99.95% by weight). Also good.

  Further, as described above, in the cellulose-containing component mainly composed of cellulose, the proportion of cellulose is, for example, 80% by weight or more (for example, 85 to 99.9% by weight), preferably 90% by weight of the whole cellulose-containing component. % Or more (for example, 93 to 99.95% by weight), more preferably 95% by weight or more (for example, 97 to 99.9% by weight).

  Cellulose-containing components (such as lignocellulose) can be used alone or in combination of two or more.

(Compound having a fluorene skeleton)
The compound having a fluorene skeleton is not particularly limited as long as it has a 9,9-bisarylfluorene skeleton (for example, 9,9-bisphenylfluorene skeleton, 9,9-bisnaphthylfluorene skeleton). Bis (aminoaryl) fluorene [eg, 9,9-bis (4-aminophenyl) fluorene, etc.], 9,9-bis (carboxyaryl) fluorene [eg, 9,9-bis (carboxyphenyl) fluorene, etc.], A compound having a fluorene skeleton having a functional group (for example, amino group, carboxyl group, hydroxyl group, epoxy group, etc.) such as 9,9-bis (hydroxyaryl) fluorene can be suitably used.

  A compound having a typical fluorene skeleton includes a compound represented by the following formula (1).

(In the formula, ring Z represents an aromatic hydrocarbon ring, R ¹ represents a substituent, X represents a heteroatom-containing functional group, R ² represents an alkylene group, R ³ represents a substituent, k Is an integer of 0 to 4, m is an integer of 0 or more, n is an integer of 1 or more, and p is an integer of 0 or more.)
In the above formula (1), examples of the aromatic hydrocarbon ring represented by the ring Z include, for example, a benzene ring, a condensed polycyclic hydrocarbon ring [for example, a condensed bicyclic hydrocarbon ring (for example, indene, naphthalene, etc. C _8-20 condensed bicyclic hydrocarbon rings, preferably C _10-16 condensed bicyclic hydrocarbon rings), condensed tricyclic hydrocarbon rings (eg anthracene, phenanthrene, etc.) And a benzene ring or a naphthalene ring is preferable. In addition, the substitution position of the ring Z substituted by 9-position of fluorene is not specifically limited. For example, when the ring Z is a naphthalene ring, the group corresponding to the ring Z substituted at the 9-position of fluorene may be a 1-naphthyl group, a 2-naphthyl group, or the like.

In the formula (1), examples of the substituent represented by the group R ¹ include a cyano group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), a hydrocarbon group [for example, an alkyl group, an aryl group ( C _6-10 aryl group such as a phenyl group)], etc.], and the like, in particular, often a halogen atom, a cyano group or an alkyl group (particularly an alkyl group). Examples of the alkyl group include C _1-6 alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and a t-butyl group (for example, a C _1-4 alkyl group, particularly a methyl group). . In addition, when k is plural (two or more), the groups R ¹ may be different from each other or the same. Further, the groups R ¹ substituted on the two benzene rings constituting the fluorene (or fluorene skeleton) may be the same or different. Further, the bonding position (substitution position) of the group R ¹ with respect to the benzene ring constituting the fluorene is not particularly limited. The preferred substitution number k is 0 to 1, in particular 0. In the two benzene rings constituting fluorene, the number of substitutions k may be the same or different from each other.

In the formula (1), examples of the hetero atom-containing functional group include a functional group having at least one selected from oxygen, sulfur and nitrogen atoms. The number of heteroatoms contained in such a functional group is not particularly limited, but may be usually 1 to 3, preferably 1 or 2. Examples of the functional group include a hydroxyl group, an epoxy-containing group (such as glycidyloxy group), a carboxyl group-containing oxygen atom-containing functional group; a mercapto group-containing sulfur atom-containing functional group; an amino group, or an N-monosubstituted amino group. [For example, N-monoalkylamino groups such as methylamino group and ethylamino group (such as N- _monoC1-4 alkylamino group), N-monohydroxyalkylamino groups such as hydroxyethylamino group (N-monohydroxy) And a nitrogen atom-containing functional group such as a C _1-4 alkylamino group. Preferred X includes a hydroxyl group, a mercapto group, an epoxy-containing group (such as a glycidyloxy group), an amino group, or an N-monosubstituted amino group, and a hydroxyl group is particularly preferable. In addition, X may be the same or different groups in different Z, and may be the same or different groups in the same ring Z.

In the formula (1), the alkylene group represented by the group R ² is not particularly limited. For example, a C _2-10 alkylene group (for example, ethylene group, trimethylene group, propylene group, butane-1, C _2-6 alkylene groups such as 2-diyl group and hexylene group) and the like, and C _2-4 alkylene groups (particularly, C _2-3 alkylene groups such as ethylene group and propylene group) are preferable. It may be. R ² may be the same or different alkylene groups (that is, when m is plural, R ² may be the same or different). That is, when m is 2 or more, the polyalkoxy (polyoxyalkylene) group [— (OR ² ) _m —] may be composed of the same oxyalkylene group, and a plurality of oxyalkylene groups (for example, oxy Ethylene group and oxypropylene group). Usually, R ² may be the same alkylene group in the same benzene ring.

The number (number of added moles) m of the oxyalkylene group (OR ² ) can be selected, for example, from a range of about 0 to 15 (eg, 1 to 10), for example, 0 to 8 (eg, 0 to 7), preferably May be 0-6, more preferably 0-5 (eg 0-3), in particular 1. M may be different in the two rings Z, or may be different in the same ring Z. For example, in the same ring Z, it may have a group -X in which m is 0 and a group-[(OR ² ) _m -X] in which m is 1 or more. In the formula (1), the number of substitutions n of the group-[(OR ² ) _m -X] depends on the type of the ring Z, but is, for example, 1 to 6, preferably 1 to 4, and more preferably. 1-3, especially 1-2 may be sufficient.

In the formula (1), examples of the substituent represented by the group R ³ include an alkyl group (eg, a C _1-12 alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group). , Preferably a C _1-8 alkyl group, more preferably a C _1-6 alkyl group, etc., a cycloalkyl group (C _5-10 cycloalkyl group such as a cyclohexyl group, preferably a C _5-8 cycloalkyl group, More preferably, it is a C _5-6 cycloalkyl group, etc., an aryl group (eg, a C _6-14 aryl group such as a phenyl group, a tolyl group, a xylyl group, a naphthyl group, preferably a C _6-10 aryl group, more preferably C, such as _6-8 aryl group), charcoal and aralkyl group (a benzyl group and _{C 6-10} aryl _{-C 1-4} alkyl group such as a phenethyl group) Hydrogen group; an alkoxy group (methoxy group, an ethoxy group, a propoxy group, _{C 1-12} alkoxy group such as butoxy, preferably _{C 1-8} alkoxy group, more preferably a _{C 1-6} alkoxy group), cycloalkoxy groups (C _5-10 cycloalkyloxy group such as cyclohexyloxy group), aryloxy group (C _6-10 aryloxy group such as phenoxy group), aralkyloxy group (for example, C _6-10 such as benzyloxy group) during group -OR ⁴ [formula and aryl _{-C 1-4} alkyl group), ^{R 4} represents a hydrocarbon group (such as the above-exemplified hydrocarbon group). An alkylthio group (a C _1-20 alkylthio group such as a methylthio group, an ethylthio group, a propylthio group or a butylthio group, preferably a C _1-8 alkylthio group, more preferably a C _1-6 alkylthio group), a cycloalkylthio group ( C _5-10 cycloalkylthio group such as cyclohexylthio group), arylthio group (C _6-10 arylthio group such as thiophenoxy group), aralkylthio group (for example, C _6-10 aryl-C ₁ such as benzylthio group) _-4 alkylthio group) or the like -SR ⁴ (wherein R ⁴ is the same as above); acyl group (C _1-6 acyl group such as acetyl group); alkoxycarbonyl group (C such as methoxycarbonyl group) _C1-4 alkoxy - carbonyl group); a halogen atom (fluorine atom, chlorine atom, bromine atom Nitro group; cyano group; mercapto group; carboxyl group; amino group; carbamoyl group; substituted amino group (for example, dialkylamino group such as dimethylamino group); sulfonyl group; Bonded substituents [eg, alkoxyaryl groups (eg, C _1-4 alkoxy C _6-10 aryl groups such as methoxyphenyl group), alkoxycarbonylaryl groups (eg, methoxycarbonylphenyl group, ethoxycarbonylphenyl group, etc. C _1-4 alkoxy-carbonyl C _6-10 aryl group etc.)] and the like.

Of these, typically, the group R ³ is a hydrocarbon group, —OR ⁴ (wherein R ⁴ represents a hydrocarbon group), —SR ⁴ (wherein R ⁴ is the same as defined above). ), An acyl group, an alkoxycarbonyl group, a halogen atom, a nitro group, a cyano group, a substituted amino group, and the like.

Preferred group R ³ includes a hydrocarbon group [eg, alkyl group (eg, C _1-6 alkyl group), cycloalkyl group (eg, C _5-8 cycloalkyl group), aryl group (eg, C _6-10 Aryl group), aralkyl group (for example, C _6-8 aryl-C _1-2 alkyl group and the like), alkoxy group (C _1-4 alkoxy group and the like) and the like. In particular, R ³ is preferably an alkyl group [C _1-4 alkyl group (particularly a methyl group)], an aryl group [eg C _6-10 aryl group (particularly a phenyl group)], or the like.

The preferred substitution number p may be 0 to 8, preferably 0 to 4 (for example, 0 to 3), more preferably 0 to 2. In different rings Z, the substitution numbers p may be the same or different from each other, and may usually be the same. In the same ring Z, when p is plural (two or more), the groups R ³ may be different from each other or the same. Further, in the two rings Z, the groups R ³ may be the same or different.

  In the formula (1), the value of n + p depends on the type of the ring Z, but may be, for example, 1 to 6, preferably 1 to 4, and more preferably about 1 to 3.

In a typical compound represented by the formula (1), ring Z is a benzene ring or naphthalene ring, X is a hydroxyl group, a mercapto group, a carboxyl group, a glycidyloxy group or an amino group (particularly a hydroxyl group), R Examples include compounds in which ² is a C _2-6 alkylene group (particularly a C _2-4 alkylene group), m is 0 to 10 (for example, 0 to 6), and n is 1 to 3.

  Typical examples of the compound represented by the formula (1) include 9,9 such as 9,9-bis (4-hydroxyphenyl) fluorene and 9,9-bis (3,4-dihydroxyphenyl) fluorene. 9,9-bis such as bis (hydroxyphenyl) fluorene; 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 9,9-bis (4-hydroxy-3,5-dimethylphenyl) fluorene (Hydroxy-alkylphenyl) fluorene; 9,9-bis (hydroxy-arylphenyl) fluorene such as 9,9-bis (4-hydroxy-3-phenylphenyl) fluorene; 9,9-bis [4- (2- 9 such as hydroxyethoxy) phenyl] fluorene, 9,9-bis [3,4-di (2-hydroxyethoxy) phenyl] fluorene , 9-bis [(hydroxyalkoxy) phenyl] fluorene; 9,9-bis [4- (2-hydroxyethoxy) -3-methylphenyl] fluorene, 9,9-bis [4- (2-hydroxyethoxy)- 9,9-bis [(hydroxyalkoxy) -alkylphenyl] fluorene such as 3,5-dimethylphenyl] fluorene; 9 such as 9,9-bis [4- (2-hydroxyethoxy) -3-phenylphenyl] fluorene , 9-bis [(hydroxyalkoxy) -arylphenyl] fluorene; compounds corresponding to these compounds, wherein ring Z is substituted with naphthalene ring, such as 9,9-bis (6-hydroxy-2-naphthyl) fluorene 9,9-bis (hydroxynaphthyl) fluorene, 9,9-bis [6- (2-hydroxyethoxy) Compounds in which X is a hydroxyl group in the above formula (1) such as 9,9-bis [(hydroxyalkoxy) naphthyl] fluorene such as 2-naphthyl] fluorene; corresponding to these compounds, X is a mercapto group, carboxyl group , A compound substituted with a glycidyl group or an amino group, and the like.

  The compounds having a fluorene skeleton may be used alone or in combination of two or more.

  The compound represented by the formula (1) may be a commercially available product, and a conventional method [for example, in the presence of an acid catalyst (sulfuric acid, hydrochloric acid, etc.) and a thiol (mercaptocarboxylic acid, etc.) Alternatively, a method of reacting fluorenones with phenols may be used.

(Mixing process)
In the mixing step, a cellulose-containing component (such as lignocellulose) and a compound having a fluorene skeleton are mixed. This kind of mixing may cause the compound having a fluorene skeleton to penetrate into the cellulose-containing component and relax the aggregate of cellulose fibers without decomposing the cellulose, or fiber-like cellulose (cellulose fibers, particularly cellulose nanofibers). ) Is formed. In particular, when a cellulose-containing component containing an amorphous component such as lignocellulose is used as the cellulose-containing component, the amorphous component (eg, lignin and hemicellulose) is selectively solubilized (or dissolved) by the compound having a fluorene skeleton. Or the aggregate of cellulose fibers is relaxed. In many cases, a part or all of the amorphous component is extracted into a compound having a fluorene skeleton in the form of a decomposition product of the amorphous component. The reason why amorphous components such as lignin are solubilized or extracted is not clear, but a compound having a fluorene skeleton penetrates into the amorphous structure of cellulose and decomposes the amorphous components while reacting with the amorphous components it is conceivable that.

  In mixing, the ratio (mixing ratio) between the cellulose-containing component and the compound having a fluorene skeleton depends on the ratio of the amorphous component in the cellulose-containing component, but for example, the former / the latter (weight ratio) = 99/1. To 1/99 (for example, 95/5 to 5/95), preferably 93/7 to 7/93 (for example, 90/10 to 10/90), more preferably 85/15 to 5/95 (for example, 80/20 to 6/94), particularly about 75/25 to 5/95 (for example, 70/30 to 7/93), and usually about 70/30 to 10/90.

  In the mixing step, a solubilization aid for promoting the solubilization of the cellulose-containing component may be used in combination with the compound having a fluorene skeleton, as long as the effects of the present invention are not impaired. As the solubilizing aid component, hydroxy compounds, nitrogen-containing cyclic ketones, amides, sulfoxides and the like can be used, and these components can be used alone or in combination of two or more.

The hydroxy compound may be composed of at least one selected from polyhydric alcohols and phenols. Examples of the polyhydric alcohol include dihydric alcohols [eg, alkanediol (eg, ethylene glycol, propylene glycol, etc.), polyalkylene glycol (eg, poly C _2-5 alkylene glycol such as polyethylene glycol, polypropylene glycol, etc.)]; Trivalent or higher polyols (eg, glycerin, diglycerin, polyglycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, etc.) can be exemplified. Examples of phenols include phenol, cresol, xylenol, resorcinol, bisphenol (bisphenol A, S, etc.) and the like. The hydroxy compound may be reactive or non-reactive in the reaction system or heat treatment system.

  Examples of the nitrogen-containing cyclic ketone include N-methyl-2-pyrrolidone, and examples of the amides include formamide, N, N-dimethylformamide, acetamide, N, N-dimethylacetamide and the like. Examples of sulfoxides include dimethyl sulfoxide. These components may be non-reactive or reactive in the reaction system or heat treatment system.

  These solubilizing auxiliary components can be used alone or in combination of two or more. Preferred solubilizing aid components include phenols, polyhydric alcohols (eg, dihydric or trihydric alcohols), N, N-dimethylacetamide, N, N-dimethylformamide, 1-methyl-2-pyrrolidone, dimethyl sulfoxide In particular, polyhydric alcohols such as glycerin are preferable.

  The solubilizing aid component has a boiling point of, for example, about 150 ° C. or higher (for example, 150 to 300 ° C.), preferably 160 to 298 ° C., and more preferably about 170 to 296 ° C. (for example, 180 to 295 ° C.). May be.

  When the solubilizing aid is used, the ratio between the compound having a fluorene skeleton and the solubilizing aid component is, for example, the former / the latter (weight ratio) = 99/1 to 20/80, preferably 98/2. It may be about 50/50 (for example, 97/3 to 55/45), more preferably about 96/4 to 60/40 (for example, 95/5 to 65/35).

  The mixing may be performed in the presence of an acid catalyst as long as the effects of the present invention are not impaired. If an acid catalyst is used, the solubilization may proceed efficiently. Examples of the acid catalyst (or acid component) include inorganic acids (for example, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, etc.), organic acids [for example, carboxylic acids (aliphatic carboxylic acids such as formic acid, acetic acid), hydroxycarboxylic acids, etc. (For example, oxalic acid, tartaric acid, citric acid, etc.), sulfonic acid (methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, etc.), etc.] Lewis acid (for example, boron trifluoride, aluminum chloride, chloride) Zinc etc.) can be exemplified. These acid catalysts can be used alone or in combination of two or more. Of these acid catalysts, inorganic acids such as sulfuric acid are preferred.

  When using an acid catalyst, the usage-amount of an acid catalyst is 0.005-10 weight part with respect to 100 weight part of compounds which have a fluorene skeleton, Preferably it is 0.01-8 weight part, More preferably, it is 0. It may be about 0.05 to 5 parts by weight.

  Depending on the reaction conditions, the cellulose itself may be decomposed, so care must be taken in using the acid catalyst depending on the type of acid catalyst and the mixing conditions. Therefore, in the present invention, the reaction may be performed without using an acid catalyst.

  Mixing may be performed in the presence of a solvent (such as a solvent described later) as necessary.

  The mixing can be selected according to the properties of the compound having a fluorene skeleton (for example, whether it is liquid or solid), the pressure at the time of mixing, etc., but is usually performed under heating (or under heating). Also good. The heating temperature is, for example, 100 to 300 ° C. (for example, 120 to 250 ° C.), preferably 150 to 300 ° C. (for example, 160 to 300 ° C.), more preferably 165 to 270 ° C. (for example, 165 to 250 ° C.). In particular, it may be about 170 to 250 ° C. The heating and mixing can be performed in an inert gas atmosphere or in air under reduced pressure, normal pressure, or increased pressure (for example, under a pressure of about 0.05 to 15 MPa).

  In many cases, the mixing is usually performed in a state where the compound having a fluorene skeleton is in a liquid state.

  The mixing time or heating time (heating mixing time) can be selected according to the mixing temperature (or reaction temperature) and the like, for example, 10 minutes or more (for example, 20 minutes to 24 hours), preferably 30 minutes or more (for example, 40 Minutes to 12 hours).

  The kind of apparatus for performing mixing (or heating mixing) is not particularly limited, and may be a batch type reaction apparatus such as a reaction kettle or a continuous reaction apparatus. In particular, when an extruder is used, the amorphous component can be efficiently solubilized while the cellulose-containing component is defibrated. Note that the device is not an open-type device, but a normally sealable device is used.

(Separation process)
Through the above mixing step, the cellulose fiber aggregate in the cellulose-containing component is relaxed and cellulose fibers are formed. In the separation step, a compound having at least a fluorene skeleton is separated from the mixture after such a mixing step. To obtain cellulose (cellulose fiber). In addition, when a cellulose containing component contains an amorphous component, an amorphous component is isolate | separated with the compound which has a fluorene skeleton. The amorphous component may be separated as it is, such as lignin, or as a further decomposed product.

  That is, as described above, when a cellulose-containing component (such as lignocellulose) containing an amorphous component such as lignin, amorphous cellulose, or hemicellulose is used as the cellulose-containing component, such an amorphous component has a fluorene skeleton. It is solubilized or extracted in the compound it has and is contained in the mixture. In many cases, such amorphous components are partly or wholly contained in the mixture in the form of a decomposed product after the mixing step. That is, in the mixture, cellulose (cellulose fiber), a compound having a fluorene skeleton, and an amorphous component extracted into the compound having a fluorene skeleton [usually a decomposition product of at least an amorphous component (for example, a lignin decomposition product, Hemicellulose degradation products, etc.)]. Such amorphous components are often contained in the mixture in a state of being dissolved (or extracted) in a compound having a fluorene skeleton. Therefore, in such a separation step of the mixture, together with the compound having a fluorene skeleton, the amorphous component solubilized or extracted in the mixing step (for example, an amorphous component containing lignin) may be separated.

  The separation method is not particularly limited, and a conventional method can be used. For example, the compound having a fluorene skeleton may be separated from the mixture by washing (or extracting) the mixture with an appropriate solvent (for example, a solvent capable of dissolving the compound having a fluorene skeleton).

  In addition, in a mixture containing an extracted amorphous component, the compound having a fluorene skeleton and the amorphous component extracted (or dissolved) in the compound having the fluorene skeleton are separated as they are as a liquid component by filtration or the like. In the same manner as described above, a compound having a fluorene skeleton and an amorphous component are washed with an appropriate solvent (for example, a compound having a fluorene skeleton or a solvent capable of dissolving both of the amorphous components). It may be separated from the mixture.

  Typically, a compound having a fluorene skeleton (and an amorphous component) may be eluted or extracted by washing the mixture with a solvent and separated from the mixture.

  The type of the solvent is not particularly limited as long as the compound having a fluorene skeleton can be dissolved, and hydrocarbons (for example, aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane; benzene, toluene, Aromatic hydrocarbons such as xylene), halogenated solvents (eg, halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride), alcohols (eg, methanol, ethanol, isopropanol, etc.), ethers (eg, Chain ethers such as ethyl ether and isopropyl ether; cyclic ethers such as dioxane and tetrahydrofuran), ketones (eg, dialkyl ketones such as acetone, methyl ethyl ketone, and isobutyl methyl ketone), cellosolves (eg, methyl cellosolve, ethyl cello) Rub, etc.), carbitols (eg, methyl carbitol), esters (eg, acetates such as methyl acetate, ethyl acetate, butyl acetate), amides (eg, dimethylformamide), sulfoxides (eg, dimethyl sulfoxide) And nitriles (acetonitrile, benzonitrile, etc.). These solvents can be used alone or as a mixed solvent.

  Of these solvents, alcohols (particularly methanol), cyclic ethers (particularly 1,4-dioxane), nitriles, and the like are preferable. The solvent may be a mixed solvent with water.

  In the separation step, a conventional method (for example, separation means such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a separation means combining these) may be used.

  In the separation step, the compound having a fluorene skeleton and the non-crystalline component are separated, but as described later, the compound having the fluorene skeleton and the non-crystalline component are allowed to remain in the cellulose fiber without being separated. Also good.

  Further, the compound having a fluorene skeleton separated in the separation step can be recovered, and the recovered compound having a fluorene skeleton may be used again in the mixing step. For example, a compound having a fluorene skeleton may be recovered from a mixture containing a compound having a fluorene skeleton and an extracted amorphous component using a conventional purification method.

  As described above, the compound having a fluorene skeleton, and further the amorphous component and / or the decomposition product thereof are separated from the mixture to obtain cellulose. In addition, a cellulose is normally obtained as a fiber-like cellulose (cellulose fiber) reflecting the form of the cellulose in the cellulose containing component as a raw material. In many cases, the cellulose contains at least fibrous cellulose, but a part of the cellulose may be contained in the form of powder.

  Such cellulose fibers may be further purified using a conventional method (for example, separation means such as filtration and concentration, or a separation means combining these).

(Defibration process)
Cellulose fibers are formed by the separation step. In the method of the present invention, although not necessary, in order to further relax the cellulose fiber, after the separation step, a cellulose fiber (crude cellulose fiber) obtained through the separation step is further defibrated. You may go out.

  In the defibrating step, defibrating can be usually performed by defibrating cellulose fibers (or cellulose) in a solvent. Examples of the solvent include water and the like in addition to the same solvents as those exemplified above. Defibration may be usually performed by dispersing cellulose fibers in a solvent that does not dissolve (or hardly dissolves) cellulose (or a poor solvent for cellulose). A typical solvent (dispersion medium) is water.

  The defibrating method (defibrating treatment) is not particularly limited as long as it can further relax cellulose. For example, mechanical treatment [eg, homogenizer, mill (bead mill, ball mill, etc.), mixer, grinder, Defibration treatment using a dispersion medium such as a paint shaker], ultrasonic treatment, and the like. The defibrating treatment may be performed alone or in combination of two or more.

[Cellulose fiber]
Cellulose is obtained as described above. Such cellulose is usually in the form of fiber [or fiber (fiber) cellulose]] as described above.

  In the present invention, the cellulose structure is relaxed by a compound having a fluorene skeleton (and an amorphous component is extracted), so that a cellulose fiber (or fibrous cellulose) reflecting a relatively low-order structure is obtained. For example, the average fiber diameter of the cellulose fiber may be about 0.5 nm to 1 μm, preferably 1 to 500 nm, more preferably about 2 to 100 nm (for example, 3 to 50 nm). The average fiber length of the cellulose fiber may be about 10 nm to 100 μm, preferably about 50 nm to 80 μm, and more preferably about 100 nm to 50 μm.

  Usually, in the method of the present invention, cellulose fibers having a fiber diameter of nanometer size (or nanometer order), that is, cellulose nanofibers are often obtained.

  In the present invention, as described above, the compound having a fluorene skeleton is removed in the separation step, and a high-quality and highly crystalline cellulose fiber is obtained, but the cellulose fiber is in a form in which some of such components remain. May be included. Such a compound having a remaining fluorene skeleton is contained in the cellulose fiber by modifying the hydroxyl group contained in the cellulose and acts as a component for improving the hydrophobicity and heat resistance of the cellulose fiber. Therefore, it is preferable that the cellulose fiber contains a compound having a fluorene skeleton. The ratio of the compound having a fluorene skeleton in the cellulose fiber is, for example, 0.001 to 20% by weight, preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight (for example, 0.1 About 3% by weight).

  Similarly, in the cellulose fiber, part of the amorphous component (for example, lignin, hemicellulose, or a decomposition product thereof) may remain in the cellulose fiber. For example, lignin and its degradation products may be able to improve the heat resistance of cellulose fibers or improve the dispersibility of cellulose fibers with respect to organic polymers (affinity between cellulose fibers and organic polymers). In addition, the ratio of the amorphous component in cellulose fiber and / or its degradation product (for example, lignin degradation product etc.) is 0.001 to 20 weight%, for example, Preferably it is 0.01 to 10 weight%, More preferably, it is 0. It may be about 0.05 to 5% by weight (for example, 0.1 to 3% by weight).

  In addition, a cellulose fiber can also be made into a desired shape or form (for example, non-fibrous forms, such as a granular form) by processing by a conventional method according to a use.

Cellulose fiber (or cellulose) may be derivatized. Derivatization yields derivatized cellulose fibers. Such a cellulose derivative can be appropriately selected depending on the use of the composite material to be described later, for example, esterified cellulose [or cellulose ester, for example, acylated cellulose (for example, cellulose acetate, cellulose Pioneto, cellulose butyrate, cellulose C _2-4 acylate such as cellulose acetate propionate, lauroylated cellulose, stearoylation cellulose, such benzoylated cellulose), etc.], etherified cellulose [or cellulose ethers, such as alkyl celluloses (e.g., methylcellulose, _{C 1-4} alkyl celluloses such as ethyl cellulose), hydroxyalkyl cellulose (e.g., hydroxyethyl cellulose, hydroxypropyl B hydroxyalkyl C _2-4 alkyl celluloses such as pills cellulose), etc. carboxyalkyl cellulose (such as carboxymethyl cellulose)], other such cyanoethylated cellulose, a coupling agent (e.g., treated with a silane such as coupling agent) A cellulose etc. are mentioned.

  The derivatized cellulose can be obtained by a conventional method. For example, acylated cellulose (cellulose fiber) can be obtained by reacting cellulose (cellulose fiber) with an acylating agent (such as acetic anhydride).

[Resin composition or composite material]
The cellulose of the present invention (particularly cellulose fiber such as cellulose nanofiber) or a derivative thereof (for example, cellulose ester fiber) has various uses, for example, reinforcing agent, coating agent, fiber raw material (for example, raw material such as nonwoven fabric). It is suitable for such as. For example, the cellulose (cellulose fiber or the like) or derivative of the present invention can be mixed with a resin as a reinforcing agent (or filler) component to obtain a resin composition (composite having high strength and high heat resistance). Material). In addition, by derivatizing cellulose (cellulose fiber), dispersibility with respect to a resin or the like may be improved.

  That is, the resin composition is composed of a resin and cellulose (such as cellulose fiber) or a derivative thereof. It does not specifically limit as resin, Any of a thermoplastic resin and a thermosetting resin (or photocurable resin) may be sufficient. These resins can be used alone or in combination of two or more.

  Examples of the thermoplastic resin include olefin resins (polyethylene, polypropylene, polymethylpentene, amorphous polyolefin, etc.), vinyl resins (acrylic resins such as polyvinyl chloride and polymethyl methacrylate, polystyrene and acrylonitrile-styrene resins). Styrenic resin, etc.), polycarbonate resin (bisphenol A type polycarbonate, etc.), polyester resin [polyalkylene arylates such as polyethylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polyarylate, liquid crystal polyester, fat Group polyester (polylactic acid, polycaprolactone, etc.)], polyacetal resin, polyamide resin (nylon 6, nylon 66, Iron 46, nylon 6T, nylon MXD, etc.), polyphenylene ether resin (modified polyphenylene ether, etc.), polysulfone resin (polysulfone, polyethersulfone, etc.), polyphenylene sulfide, polyether ketone, polyether ether ketone, polyether imide, polyamide imide , Polyamino bismaleimide, bismaleimide triazine resin, thermoplastic elastomer, fluorinated resin and the like. Examples of the thermosetting resin include phenol resin, furan resin, urea resin, melamine resin, unsaturated polyester, epoxy resin, urethane resin, silicone resin, polyimide resin, diallyl phthalate resin, vinyl ester resin, and the like. .

An aliphatic polyester resin may be suitably used as the thermoplastic resin. Examples of the aliphatic polyester include polylactic acid, polyalkylene alkanoates [for example, polyalkylene succinate (for example, polyethylene succinate, polybutylene succinate), polyalkylene adipate (for example, polyethylene adipate, polybutylene adipate), alkane Esters of diols with a plurality of C _2-10 alkanedicarboxylic acids (eg polybutylene succinate adipate)], poly (alkylene alkanoates / arylate) [eg polybutylene adipate / terephthalate, polytetramethylene adipate / terephthalate], Poly (alkylene alkanoates / carbonates) (eg polybutylene succinate / carbonates, etc.), polyalkylene alkanoates / polyaliphatic oxycarbohydrates Acids (eg, polybutylene succinate / polylactic acid), polyalkylene alkanoates / polylactones (eg, polybutylene succinate / polycaprolactone), polyaliphatic oxycarboxylic acids (eg, polyglycolic acid, polyhydroxybutyrate) Rate, polyhydroxy C _2-6 alkanoic acid other than polylactic acid such as polyhydroxybutyrate / polyhydroxyhexanoate), polylactone (for example, polycaprolactone) and the like. Aliphatic polyester resins may be used alone or in combination of two or more. In particular, the thermoplastic resin may be composed of at least polylactic acid. Polylactic acid does not have sufficient heat resistance, and its practical use is greatly limited. However, polylactic acid, like polylactic acid, can significantly improve heat resistance by combining with the cellulose of the present invention derived from biomass or its derivatives. Can do.

  In addition, the cellulose (cellulose fiber or the like) or a derivative thereof of the present invention has an excellent affinity for a resin having a fluorene skeleton (for example, a 9,9-bisarylfluorene skeleton), and a composite material with such a resin is used. You may form suitably.

  Examples of the resin having a fluorene skeleton include a resin containing a compound having a 9,9-bisarylfluorene skeleton (for example, a compound represented by the formula (1)) as a polymerization component. Such a resin can be selected according to the type of the functional group X in the formula (1). For example, in the formula (1), a compound in which X is a hydroxyl group can be used as a polyol component of the resin, A compound in which X is a carboxyl group can be used as a dicarboxylic acid component of the resin. Moreover, in the said Formula (1), the compound etc. whose X is an epoxy-containing group can also be used as it is as a thermosetting resin (epoxy resin etc.).

  As a typical resin having a fluorene skeleton, a resin {for example, a thermoplastic resin [polyester] having a compound represented by the above formula (1) (a compound in which X is a hydroxyl group) as a polyol component (for example, a diol component). Resin, polycarbonate resin, polyurethane resin, etc.], thermosetting resin {for example, unsaturated polyester resin, thermosetting polyurethane resin, epoxy resin (polyglycidyl ether, etc.), vinyl ester resin, phenol resin, acrylic resin [for example, Polyol poly (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, etc.]}, a compound represented by the above formula (1) (compound in which X is a mercapto group) is a polythiol component (for example, a dithiol component )) Resin {for example, thermoplastic resin [ Lithioester resin, polythiocarbonate resin, polythiourethane resin, polysulfone resin, polythioether resin, etc.], thermosetting resin (for example, thermosetting polythiourethane resin, thioepoxy resin, polythiol poly (meth) acrylate, etc.), Resins having a compound represented by the formula (1) (compound in which X is a carboxyl group) as a polycarboxylic acid component (for example, dicarboxylic acid component) {for example, thermoplastic resin (polyamide resin, polyester resin, etc.), heat Curable resins (such as unsaturated polyester resins)], resins having a compound represented by the formula (1) (a compound in which X is an amino group) as a polyamine component (for example, a diamine component) {for example, a thermoplastic resin (Polyamide resin, thermoplastic polyimide resin, etc.), thermosetting resin (polyimide resin) , Aniline resin)], and others.

The epoxy resin having a fluorene skeleton includes compounds in which X is an epoxy group-containing group in the formula (1), for example, 9,9-bis (glycidyloxyaryl) fluorenes {for example, 9,9-bis ( Glycidyloxyphenyl) fluorene [eg, 9,9-bis (4-glycidyloxyphenyl) fluorene, etc.], 9,9-bis (alkyl-glycidyloxyphenyl) fluorene [eg, 9,9-bis (4-glycidyloxy) 9,9-bis (mono- or di-C _1-4 alkyl-glycidyloxyphenyl) fluorene such as -3-methylphenyl) fluorene, 9,9-bis (4-glycidyloxy-3,5-dimethylphenyl) fluorene] 9,9-bis (aryl-glycidyloxyphenyl) fluorene [eg, 9,9 9,9-bis (mono- or di-C _6-10 aryl-glycidyloxyphenyl) fluorene] such as bis (4-glycidyloxy-3-phenylphenyl) fluorene, 9,9-bis (di-to-tetraglycidyloxyphenyl) ) 9,9-bis (glycidyloxyphenyl) fluorenes such as fluorene [eg, 9,9-bis (3,4-diglycidyloxyphenyl) fluorene]; 9,9-bis (glycidyloxynaphthyl) fluorene ( For example, 9,9-bis (glycidyloxynaphthyl) fluorenes such as 9,9-bis (6-glycidyloxy-2-naphthyl) fluorene)}, 9,9-bis (glycidyloxy (poly) alkoxyaryl) Fluorenes {as opposed to 9,9-bis (glycidyloxyaryl) fluorenes A compound in which m is 1 or more, for example, 9,9-bis (glycidyloxy C _2-4 alkoxyphenyl) fluorene [for example, 9,9-bis [4- (2-glycidyloxyethoxy) phenyl] Fluorene etc.], 9,9-bis (C _1-4 alkyl-glycidyloxy C _2-4 alkoxyphenyl) fluorene [eg, 9,9-bis (4- (2-glycidyloxyethoxy) -3-methylphenyl) Fluorene, 9,9-bis (4- (2-glycidyloxyethoxy) -3,5-dimethylphenyl) fluorene, etc.], 9,9-bis (glycidyloxydi to tetra C _2-4 alkoxyphenyl) fluorene [for example 9,9-bis {4- [2- (2-glycidyloxyethoxy) ethoxy] phenyl} fluorene etc.] 9,9-bis (glycidyloxy (poly) alkoxyphenyl) fluorenes; 9,9-bis (glycidyloxy C _2-4 alkoxynaphthyl) fluorene (eg, 9,9-bis [6- (2-glycidyloxyethoxy) 9,9-bis (glycidyloxy (poly) alkoxynaphthyl) fluorenes, etc.) such as))-2-naphthyl] fluorene).

The poly (meth) acrylate having a fluorene skeleton includes compounds in which X is substituted with a (meth) acryloyloxy group in the above formula (1), such as 9,9-bis ((meth) acryloyloxyaryl) fluorenes. {For example, 9,9-bis ((meth) acryloyloxyphenyl) fluorene [for example, 9,9-bis (4- (meth) acryloyloxyphenyl) fluorene, etc.], 9,9-bis (alkyl- (meth) Acryloyloxyphenyl) fluorene [eg, 9,9-bis (4- (meth) acryloyloxy-3-methylphenyl) fluorene, 9,9-bis (4- (meth) acryloyloxy-3,5-dimethylphenyl) 9,9-bis (mono- or di-C _1-4 alkyl- (meth) acryloyloxyphs such as fluorene Nenyl) fluorene], 9,9-bis (aryl- (meth) acryloyloxyphenyl) fluorene [e.g., 9,9- such as 9,9-bis (4- (meth) acryloyloxy-3-phenylphenyl) fluorene Bis (mono or di C _6-10 aryl- (meth) acryloyloxyphenyl) fluorene], 9,9-bis (di-tetra (meth) acryloyloxyphenyl) fluorene [eg 9,9-bis (3,4 9,9-bis ((meth) acryloyloxyphenyl) fluorenes such as -di (meth) acryloyloxyphenyl) fluorene]; 9,9-bis ((meth) acryloyloxynaphthyl) fluorene (for example, 9,9 9,9-bi, such as -bis (6- (meth) acryloyloxy-2-naphthyl) fluorene) S ((meth) acryloyloxynaphthyl) fluorenes, etc.}, 9,9-bis ((meth) acryloyl (poly) alkoxyaryl) fluorenes {9,9-bis ((meth) acryloyloxyaryl) fluorenes A compound in which m is 1 or more, for example, 9,9-bis ((meth) acryloyloxy C _2-4 alkoxyphenyl) fluorene [eg, 9,9-bis [4- (2- (meth) acryloyl) Oxyethoxy) phenyl] fluorene and the like], 9,9-bis (C _1-4 alkyl- (meth) acryloyloxy C _2-4 alkoxyphenyl) fluorene [eg, 9,9-bis (4- (2- (meta ) Acryloyloxyethoxy) -3-methylphenyl) fluorene, 9,9-bis (4- (2- (meth) acryloyl) Oxy) -3,5-dimethylphenyl) fluorene, etc.], 9,9-bis ((meth) acryloyloxy di- to tetra _{C 2-4} alkoxyphenyl) fluorene [e.g., 9,9-bis {4- [2 9,9-bis ((meth) acryloyloxy (poly) alkoxyphenyl) fluorenes such as — (2- (meth) acryloyloxyethoxy) ethoxy] phenyl} fluorene, etc .; 9,9-bis ((meth) acryloyl) 9,9-bis ((meth) acryloyloxy such as oxy C _2-4 alkoxynaphthyl) fluorene (eg, 9,9-bis [6- (2- (meth) acryloyloxyethoxy) -2-naphthyl] fluorene) (Poly) alkoxynaphthyl) fluorenes, etc.}.

  In the resin composition, the ratio of cellulose (cellulose fiber or the like) or a derivative thereof is, for example, 0.5 to 1000 parts by weight, preferably 1 to 500 parts by weight, more preferably 5 to 300 parts by weight with respect to 100 parts by weight of the resin. The amount may be about 1 part by weight, usually about 1 to 150 parts by weight (for example, 2 to 100 parts by weight, preferably 2 to 80 parts by weight, more preferably 3 to 50 parts by weight, particularly 5 to 30 parts by weight). There may be.

  The resin composition may be used as it is as a composite material (reinforcing agent-containing resin composition) depending on the type of resin, or may be cured as necessary. For example, the resin composition may form a cured product when the resin is a thermosetting resin. That is, the cured product is the resin composition [that is, a resin composition containing a thermosetting resin (for example, a thermosetting resin having a 9,9-bisarylfluorene skeleton) and a cellulose fiber or a derivative thereof]. Is a cured product. In addition, when forming hardened | cured material, the said resin composition may contain the hardening | curing agent, the hardening catalyst, etc. as needed.

[Extractant]
In the present invention, as described above, the compound having a fluorene skeleton selectively solubilizes or extracts the non-crystalline component in the cellulose-containing component, and the non-crystalline component from the solubilized or extracted cellulose-containing component. By separating the cellulose, cellulose [particularly, cellulose fiber (or fibrous cellulose)] can be obtained.

  That is, in the production method, the compound having a fluorene skeleton acts as an extractant for separating an amorphous component by extraction from a cellulose-containing component containing an amorphous component such as lignocellulose. Specifically, using such an extractant, it is possible to extract an amorphous component and / or a decomposition product thereof (eg, black liquor) from a cellulose-containing component. Therefore, in the present invention, for extracting an amorphous component (for example, an amorphous component containing lignin) from a cellulose-containing component (for example, lignocellulose) containing an amorphous component [specifically, by extracting cellulose ( For example, an extractant (non-crystalline component extractant) for obtaining fibrous cellulose), which is composed of the compound having the fluorene skeleton, is also included.

  The extractant may be composed of only a compound having a fluorene skeleton, and may contain other extractant components (or solubilizing aids). Examples of such components include solubilizing aids exemplified in the section of the mixing step. Other extractant components may be used alone or in combination of two or more.

  When other extractant component (solubilization aid) is used, the ratio between the compound having a fluorene skeleton and the solubilization aid component is, for example, the former / the latter (weight ratio) = 99/1. -20/80, preferably 98/2 to 50/50 (eg 97/3 to 55/45), more preferably about 96/4 to 60/40 (eg 95/5 to 65/35). May be.

  Moreover, the extractant may contain a solvent component and an acid catalyst as needed. As the solvent component and the acid catalyst, the above-exemplified components and acid catalysts can be used, and the ratio to the compound having a fluorene skeleton can also be selected from the same range as described above.

  The property of the extractant may be liquid at normal temperature (for example, about 15 to 25 ° C.), or may be solid at normal temperature as long as it can be made liquid when mixed with the cellulose-containing component.

  In addition, the extraction method of an amorphous component with an extracting agent is the same as the mixing process of the manufacturing method of the said fiber, and mixing conditions etc. are also the same. That is, the amorphous component in a cellulose containing component can be extracted by mixing a cellulose containing component and an extractant. In addition, although the mixture (extract) after extraction contains an extractant and an amorphous component (and / or a decomposition product thereof), the extractant can be easily recovered from such a mixture by a conventional method. can do.

  In addition, the extract contains an extractant and a non-crystalline component and / or a degradation product thereof [for example, lignin, hemicellulose, amorphous cellulose, and degradation products thereof (lignin degradation product, oligosaccharide, etc.), etc.] Since it is a component (for example, black liquor), the extract itself can also be used as various raw materials (for example, resin monomers). In addition, you may use an extract, removing a part of component as needed.

  In the extract, the ratio of the decomposition product of the amorphous component is, for example, 1 to 100% by weight, preferably 2 to 90% by weight, more preferably 5 to 85% by weight, particularly 10 to 80% by weight (for example 20 to 20%). 70% by weight). When the extract contains an extractant, the ratio of the extractant (or the compound having a fluorene skeleton) is, for example, 0.1 to 90% by weight, preferably 0.3 to 80% by weight, and more preferably 0. It may be about 5 to 70% by weight.

  In addition, the form of the extract may be liquid or semi-solid at room temperature (15 to 25 ° C.). In particular, the viscosity of the extract (liquid composition) is, for example, 1 to 3000 mPa · s, preferably 2 to 2000 mPa · s, more preferably 3 to 1000 mPa · s (for example, 5 to 800 mPa · s) at 25 ° C. It may be a degree.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Example 1
5 g of Yonematsu (manufactured by Jeon Co., Ltd.) crushed to 100 mesh and 50 g of 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (BPEF, manufactured by Osaka Gas Chemical Co., Ltd.) are placed in a 100 ml autoclave. And heated in an oil bath at 220 ° C. for 60 minutes. Then, 100 ml of a mixed solvent of 1,4-dioxane and water (the former / the latter (weight ratio) = 90/10) is added to the heated mixture, and the mixture is stirred until it is uniformly dispersed, and residual BPEF is removed by filtration and washing. Removed.

  The filtrate after washing was redispersed in distilled water and treated with a paint shaker for 30 minutes to obtain a fiber dispersion. The fiber dispersion was centrifuged and then dried (dried in a vacuum dryer at 60 ° C. for 3 hours) to obtain a fiber yield of 1.9 g (38% yield).

  And when it casted on the glass substrate using the obtained fiber dispersion liquid and dried at room temperature, the transparent and uniform film | membrane was obtained. A SEM photograph of the film is shown in FIG. As is clear from the SEM photograph, it was found that cellulose fibers (average diameter 100 nm, average fiber length 1.5 μm) fibrillated to the nano order were obtained.

  Furthermore, from the IR spectrum of the obtained fiber, it was confirmed that lignin and hemicellulose were removed (extracted) from the fiber, and a small amount of lignin and BPEF remained in the fiber.

  On the other hand, BPEF was recovered by concentrating the filtrate after washing, adding methanol and then recrystallizing at 10 ° C. to recover 48 g of BPEF (96% of BPEF used). .

(Example 2)
A fiber dispersion was obtained in the same manner as in Example 1 except that the heating temperature was changed to 180 ° C. instead of 220 ° C. (fiber yield 2.1 g, yield 42%). The SEM photograph of the obtained cellulose nanofiber is shown in FIG. As is clear from the SEM photograph, as in Example 1, it was found that cellulose fibers (average diameter 150 nm, average fiber length 1.8 μm) fibrillated in the nano order were obtained.

(Comparative Example 1)
After putting 5 g of Yonematsu (manufactured by Jeon Co., Ltd.) crushed to 100 mesh, 50 mL of distilled water and 1.5 g of sulfuric acid into a 100 ml three-necked flask, it was heated in an oil bath at 90 ° C. for 180 minutes. The heated mixture was filtered, and the filtrate was washed twice with 100 ml of distilled water, and then the filtrate was redispersed in water and treated with a paint shaker for 30 minutes to obtain a dispersion. The dispersion was centrifuged and then dried (dried in a vacuum dryer at 60 ° C. for 3 hours) to obtain a solid content of 1 g (yield 20%). The reason why the yield is lower than in Examples 1 and 2 is not clear, but it is assumed that cellulose is hydrolyzed.

  And when it casted on the glass substrate using the obtained fiber dispersion liquid and dried at room temperature, the opaque and nonuniform film | membrane was obtained. An SEM photograph of the film is shown in FIG. As is apparent from the SEM photograph, cellulose fibers defibrated to the nano order could not be confirmed.

(Example 3)
8.8 parts by weight of cellulose fiber obtained in Example 1, 70.0 parts by weight of 9,9-bis [4- (2-glycidyloxyethoxy) phenyl] fluorene (manufactured by Osaka Gas Chemical Co., Ltd.), curing agent 20.2 parts by weight of acid anhydride (manufactured by Hitachi Chemical Co., Ltd., HN-5500) and 1.0 part by weight of triphenylphosphine were dissolved in acetone to prepare a uniform mixed solution. The obtained mixed solution was cast on a glass substrate treated with a release agent by removing acetone under reduced pressure, and heated and cured at 110 ° C. for 5 hours using a blower dryer. When the linear expansion coefficient of the obtained cured film was measured by TMA (thermomechanical analysis), it was 9.1 × 10 ⁻⁵ / ° C. at 110 to 190 ° C.

(Comparative Example 2)
In Example 3, except that the cellulose fiber was not used, a cured film was obtained and the linear expansion coefficient was measured in the same manner as in Example 3. As a result, the linear expansion coefficient was measured at 110 to 190 ° C. 14.1 × 10 ⁻⁵ / ° C.

Example 4
In Example 3, the amount of cellulose fiber was 4.6 parts by weight, the amount of 9,9-bis [4- (2-glycidyloxyethoxy) phenyl] fluorene was 73.4 parts by weight, and the amount of acid anhydride was 21. When it was heated in the same manner as in Example 3 except that the content was changed to 0.0 parts by weight, a cured film was obtained.

(Example 5)
10 parts by weight of the cellulose fiber obtained in Example 1 and 90 parts by weight of polylactic acid (trade name “Lacia H-100J” manufactured by Mitsui Chemicals, Inc.) are dissolved in 1,4-dioxane, and a uniform mixed solution is obtained. Prepared. The resulting mixture was cast on a glass substrate with 1,4-dioxane removed under reduced pressure and dried at room temperature. When the linear expansion coefficient of the obtained film was measured by TMA, it was 9.7 × 10 ⁻⁵ / ° C. at 30 to 110 ° C. Further, the heat distortion temperature of the obtained film was improved to 110 ° C. or higher.

(Comparative Example 3)
In Example 5, except that no cellulose fiber was used, a membrane was obtained and the linear expansion coefficient was measured in the same manner as in Example 5. As a result, the linear expansion coefficient was measured, and 24.3 × 10 ⁻⁵ / ° C. at 30 to 70 ° C. Met.

  In comparison between Example 3 (and Example 4) and Comparative Example 2 and in comparison between Example 5 and Comparative Example 3, the addition of the cellulose fiber obtained in Example 1 significantly reduced the linear expansion coefficient. The cellulose fibers obtained in the examples were found to be useful as reinforcing agents.

(Example 6)
In Example 1, a cellulose fiber dispersion was obtained in the same manner as in Example 1 except that 5 g of filter paper (manufactured by Advantech, 5B) was used instead of Yonematsu. The dry yield of cellulose fibers was 3.8 g, and the yield was 76%.

  And when it casted on the glass substrate using the obtained fiber dispersion liquid and dried at room temperature, the white translucent and uniform film | membrane was obtained. An SEM photograph of the film is shown in FIG. As is clear from the SEM photograph, it was found that cellulose fibers defibrated to the nanometer order (average diameter of about 30 nm, average fiber length of 1.0 μm) were obtained.

(Example 7)
10 parts by weight of the cellulose fiber obtained in Example 6 was dispersed in a mixed solution of 100 parts by weight of pyridine and 15 parts by weight of acetic anhydride, and after acetylation modification at 80 ° C. for 60 minutes, washed with acetone and methanol and dried. Thus, an acetylated cellulose fiber (cellulose acetate fiber) was obtained.

Then, 10 parts by weight of the obtained cellulose acetate fiber and 90 parts by weight of polylactic acid (trade name “Lacia H-100J” manufactured by Mitsui Chemicals, Inc.) were compounded by the same method as in Example 5. That is, cellulose acetate fiber (nanofiber) and polylactic acid were dispersed or dissolved in 1,4-dioxane to prepare a uniform mixed solution. The obtained mixed solution was cast on a glass substrate, dried at room temperature, and then formed into a film with a hot press molding machine. A photograph of the obtained film (film is a square piece at the center of the photograph) is shown in FIG. When the linear expansion coefficient of the obtained film was measured by TMA, it was 9.9 × 10 ⁻⁵ / ° C. at 30 to 110 ° C. Further, the heat distortion temperature of the obtained film was improved to 166 ° C. or higher.

(Example 8)
A film was obtained in the same manner as in Example 7 except that the ratio of each component was changed to 30 parts by weight of cellulose acetate fiber and 70 parts by weight of polylactic acid. When the linear expansion coefficient of the obtained film was measured by TMA, it was 5.6. × 10 ^-5 / ° C. Further, the heat distortion temperature of the obtained film was improved to 166 ° C. or higher.

Example 9
A film was obtained in the same manner as in Example 7 except that the ratio of each component was changed to 5 parts by weight of cellulose acetate fiber and 95 parts by weight of polylactic acid. When the linear expansion coefficient of the obtained film was measured by TMA, it was 19.8 × 10 ⁻⁵ / ° C. at 30 to 110 ° C. Moreover, the heat distortion temperature of the obtained film was improved to 165 degreeC or more.

  In the present invention, cellulose is efficiently produced in a fibrous form (particularly, in the form of cellulose nanofiber) from a cellulose-containing component (particularly, a cellulose containing an amorphous component such as lignocellulose, a cellulose-containing component containing cellulose as a main component). Can get well. And such a cellulose fiber has the outstanding characteristic, For example, it can utilize as a reinforcing agent of resin other than materials, such as a woven fabric (nonwoven fabric etc.), a film, clothing.

Claims (8)

A method for producing cellulose from a cellulose-containing component , comprising mixing a cellulose-containing component and a compound having a 9,9-bisarylfluorene skeleton represented by the following formula (1), and through this step from the mixture obtained, the production method of cellulose and a separation step of separating the compound having at least the 9,9-bisaryl fluorene skeleton.
(In the formula, ring Z represents an aromatic hydrocarbon ring, R ¹ represents a substituent, X represents a heteroatom-containing functional group, R ² represents an alkylene group, R ³ represents a substituent, k Is an integer of 0 to 4, m is an integer of 0 or more, n is an integer of 1 or more, and p is an integer of 0 or more.)   The manufacturing method of Claim 1 which manufactures fibrous cellulose. 3. The production according to claim 1, wherein in the mixing step, the cellulose-containing component and the compound having a 9,9-bisarylfluorene skeleton are mixed at a ratio of the former / the latter (weight ratio) = 85/15 to 5/95. Method. The manufacturing method according to any one of claims 1 to 3 , wherein the mixing step is performed under heating at 160 to 300 ° C. The cellulose-containing component is lignocellulose, and the non-crystalline component containing lignin is solubilized or extracted from the lignocellulose in the mixing step with a compound having a 9,9-bisarylfluorene skeleton, and the 9,9-bisarylfluorene is separated in the separation step. The manufacturing method according to any one of claims 1 to 4 , wherein the amorphous component is separated together with the compound having a skeleton. The manufacturing method in any one of Claims 1-5 which manufactures a cellulose nanofiber using the cellulose containing component which contains a cellulose in the ratio of 80 weight% or more. The production method according to any one of claims 1 to 6 , further comprising a defibrating step of defibrating the fiber-like cellulose obtained through the separation step. An extractant for decomposing and extracting the amorphous component from a cellulose-containing component containing cellulose and an amorphous component without using an acid catalyst to obtain the cellulose, wherein the formula (1) An extractant composed of a compound having a 9,9-bisarylfluorene skeleton represented by the formula: