JP6520619B2 - Fine fibrous cellulose content - Google Patents

Description

  The present invention relates to a fine fibrous cellulose content. Specifically, the present invention relates to a fine fibrous cellulose-containing material comprising fine fibrous cellulose having a predetermined phosphoric acid group.

  BACKGROUND ART In recent years, materials using renewable natural fibers have attracted attention due to substitution of petroleum resources and heightened environmental awareness. Among natural fibers, fibrous cellulose with a fiber diameter of 10 to 50 μm, particularly fibrous cellulose (pulp) derived from wood, has been widely used mainly as a paper product.

  As fibrous cellulose, fine fibrous cellulose having a fiber diameter of 1 μm or less is also known. In the sheet or the composite containing the fine fibrous cellulose, the tensile strength is greatly improved because the contact points between the fibers are significantly increased. In addition, when the fiber width is shorter than the wavelength of visible light, the transparency is greatly improved. For example, Patent Document 1 discloses a fiber-reinforced composite material in which high transparency is maintained without being affected by temperature conditions, wavelengths, etc., and various functionalities are imparted by compounding the fiber with a matrix material. It is done. It is also known that fine fibrous cellulose can be used for applications such as thickeners.

  Moreover, the fine fibrous cellulose which modified | reformed the surface of fine fibrous cellulose is also known (for example, patent documents 2-4). Patent Document 2 discloses a surface-modified fine fibrous cellulose obtained by linking a hydrocarbon group to a carboxyl group of a carboxyl group-containing fine fibrous cellulose via an amide bond. Patent Document 3 discloses a surface-modified fibrillar cellulose in which an amine having an ethylene oxide / propylene oxide (EO / PO) copolymer moiety is bonded as a salt to a carboxyl group of a carboxyl group-containing fibrillar cellulose. It is done. Further, Patent Document 4 discloses a rubber composition containing surface-modified fine fibrous cellulose obtained by treating a carboxyl group-containing fine fibrous cellulose with a hydrophobic modifying agent having a hydrocarbon group. There is. As described above, it has been studied to improve the compatibility with the resin and the solvent by modifying the surface of the fine fibrous cellulose.

JP 2008-24788 A JP, 2013-216998, A JP, 2015-143336, A JP, 2014-125607, A

  However, even in the conventional surface-modified fibrillar cellulose, the compatibility with the resin and the solvent is not sufficient, and in the resin composition containing the surface-modified fibrillar cellulose, the strength and the transparency are sufficiently obtained. As a result of the study of the present inventors, it has become clear that there are concerns that

  Then, in order to solve the subject of such a prior art, the present inventors advanced examination for the purpose of providing the fine fibrous cellulose containing substance excellent in compatibility with resin and a solvent.

As a result of intensive studies to solve the above problems, the present inventors have found that (a) phosphoric acid group and organic group having one or more carbon atoms are covalently bonded to fine fibrous cellulose. It has been found that the compatibility with a resin and a solvent is improved by containing a group and a phosphoric acid group having (b) an organic group having one or more carbon atoms.
Specifically, the present invention has the following configuration.

[1] A fine fibrous cellulose-containing material containing fine fibrous cellulose, wherein the fine fibrous cellulose is (a) a group formed by covalent bonding of a phosphoric acid group and an organic group having one or more carbon atoms (B) A fine fibrous cellulose-containing material having a phosphoric acid group having no organic group having one or more carbon atoms.
[2] (a) A group formed by covalent bonding of a phosphate group and an organic group having 1 or more carbon atoms is an ester bond or silyl ester bond of a phosphate group and an organic group having 1 or more carbon atoms The fine fibrous cellulose-containing substance according to [1], which is a group formed by bonding by at least one selected from ether bond, urethane bond and amide bond.
[3] The fine fibrous cellulose-containing material according to [1] or [2], wherein the carbon number of the organic group is 10 or less.
[4] The organic group is derived from at least one selected from silane compounds, halogenated alkyl compounds, isocyanate compounds, epoxy compounds, acetylated compounds, amine compounds, tosylates / mesylates / analogues thereof, carboxylic acids, and vinyl resins The fine fibrous cellulose content thing in any one of [1]-[3] which is group.
[5] A fine fibrous cellulose-containing resin composition comprising the fine fibrous cellulose-containing material according to any one of [1] to [4] and a resin.

  According to the present invention, it is possible to obtain a fine fibrous cellulose-containing material containing fine fibrous cellulose which is excellent in compatibility with a resin and a solvent.

FIG. 1 is a graph showing the relationship between the amount of dropped NaOH and the electrical conductivity with respect to the fiber material.

Hereinafter, the present invention will be described in detail. The description of the configuration requirements described below may be made based on typical embodiments and specific examples, but the present invention is not limited to such embodiments. In addition, the numerical range represented using "-" in this-application specification means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.
Moreover, the value regarding the mass of fibers, such as a cellulose, is based on bone dry mass (solid content) except the case where it describes especially. "A and / or B" refers to at least one of A and B unless otherwise specified, and may be A alone or B alone, or both A and B. It means that it may be.

(Fine fibrous cellulose content)
The present invention relates to a fine fibrous cellulose-containing material containing fine fibrous cellulose. The fine fibrous cellulose contained in the fine fibrous cellulose-containing substance of the present invention comprises (a) a group formed by covalent bonding of a phosphoric acid group and an organic group having one or more carbon atoms, and (b) a carbon number And at least one phosphate group not having an organic group. Thus, since the fine fibrous cellulose has an organic group having one or more carbon atoms, the fine fibrous cellulose used in the present invention can also be referred to as surface-modified fine fibrous cellulose.

  The fine fibrous cellulose-containing material of the present invention has the above-mentioned constitution, and is excellent in compatibility with a resin and a solvent. For example, when the fine fibrous cellulose has excellent compatibility with the resin, the molded product formed from the resin composition has an excellent flexural modulus. Moreover, since the aggregate of fine fibrous cellulose does not exist in such a resin composition and a molded object, or it is a trace amount even if it exists, a resin composition and a molded object are excellent in transparency.

In the present invention, a group (hereinafter also referred to as a group of (a)) in which the (a) phosphate group of the fine fibrous cellulose and the organic group having one or more carbon atoms are covalently bonded ( The total content of b) a phosphoric acid group having one or more carbon atoms and having no organic group (hereinafter sometimes referred to as a group of (b)) is preferably 0.1 mmol / g or more. The total content of the group of (a) and the group of (b) is more preferably 0.5 mmol / g or more, still more preferably 0.7 mmol / g or more, and 0.8 mmol / g or more Is further more preferable, and particularly preferably 0.9 mmol / g or more. The upper limit value of the total content of the group of (a) and the group of (b) is preferably 5 mmol / g.
By making the total content of the group of (a) and the group of (b) into the above range, the dispersibility of the fine fibrous cellulose in the fine fibrous cellulose-containing substance can be made favorable. Thereby, the transparency of the fine fibrous cellulose-containing substance can be enhanced.

The phosphoric acid group introduction amount before the introduction of the organic group having one or more carbon atoms is refined by the process to be described later, and the obtained fine fibrous cellulose-containing slurry is treated with an ion exchange resin, It can be measured using a conductivity titration method that determines the change in electrical conductivity while adding an aqueous sodium hydroxide solution.
In the treatment using an ion exchange resin, 1/10 strongly acidic ion exchange resin (for example, Amberjet 1024; Organo Corporation, conditioned) is added to the fine fibrous cellulose-containing slurry and shaken for 1 hour Then, pour on a mesh of about 90 μm, and separate the resin and the slurry.
In conductivity titration, the addition of alkali gives the curve shown in FIG. At the beginning, the electrical conductivity drops sharply (hereinafter referred to as "first region"). Thereafter, the conductivity starts to rise slightly (hereinafter referred to as "the second region"). After that, the increment of conductivity increases (hereinafter, referred to as "third region"). That is, three regions appear. Among them, the amount of alkali required in the first region is equal to the amount of strongly acidic groups in the slurry used for titration, and the amount of alkali required in the second region is the amount of weakly acidic groups in the slurry used for titration Become equal. When the phosphoric acid group causes condensation, the weakly acidic group is apparently lost, and the amount of alkali required for the second region is smaller than the amount of alkali required for the first region. On the other hand, since the amount of strongly acidic groups is the same as the amount of phosphorus atoms regardless of the presence or absence of condensation, the amount of introduction of phosphoric acid groups (or the amount of phosphoric acid groups) or the amount of introduction of substituents (or the amount of substitution groups) When said, it represents the amount of strongly acidic groups.

  The introduced amounts of the group (a) and the group (b) are derived as follows. The group (a) is obtained by introducing an organic group having 1 or more carbon atoms into a phosphoric acid group before the introduction of an organic group having 1 or more carbon atoms. When an organic group having one or more carbon atoms is introduced, first, the amount of weakly acidic group is reduced to be in the state of the following (A). Next, the amount of strongly acidic groups is reduced, resulting in the following state (A ').

After calculating the amount of phosphoric acid group (P ₀ ) before the introduction of the organic group having 1 or more carbon atoms by the conductivity titration method described above, the introduced amount of the group of (a) and the group of (b) is conducted Calculated by titration method. The introduction amount of each group can be determined by the following equation. The amount of phosphoric acid group (P ₀ ) can also be calculated from the atomic weight of phosphorus which can be measured by performing XRF, molybdenum blue method or the like on the fine fibrous cellulose after the introduction of the organic group. is there.
State (A) organic group introduction amount (a) = titration amount required for the first region-titration amount required for the second region Introduction amount (b) of the group to which the organic group in the state (B) is not introduced titre state required for the second region (a ') an organic group introduced amount of _{(a') = (P 0} ) - (a)
Organic group introduction amount = (a) + (a ')
The organic group introduction amount is the content of the group of (a). The introduction amount of the group to which the organic group in the state (B) is not introduced is the content of the group of (b).

0.005 mmol / g or more is preferable, as for content of group of (a), 0.01 mmol / g or more is more preferable, and 0.05 mmol / g or more is still more preferable. The upper limit value of the content of the group (a) is preferably 4 mmol / g.
0.005 mmol / g or more is preferable, 0.007 mmol / g or more is more preferable, and, as for content of (b), 0.009 mmol / g or more is still more preferable. The upper limit of the content of the group (b) is preferably 5 mmol / g.

<Group of (a) / group of (b)>
The fine fibrous cellulose includes (a) a group formed by covalent bonding of a phosphate group and an organic group having one or more carbon atoms, and (b) a phosphate group having no organic group having one or more carbon atoms. And.
In the present specification, the phosphate group is a divalent functional group corresponding to phosphoric acid from which a hydroxyl group has been removed. It is specifically a group represented by -PO ₃ H _2. Further, the phosphate group may be a group represented by -PO ₃ M _2. M is a monovalent or higher cation, and is selected from a hydrogen ion, a metal ion, and an organic ion.

Since a phosphoric acid group shows bivalent acid when introduce | transduced into a cellulose, it produces an electrical repulsive force and can suppress aggregation of cellulose fibers. Such a repulsive force is considered to be larger than that in the case of introducing a monovalent functional group such as a carboxyl group or a cationic group into cellulose.
Further, since the phosphoric acid group is a divalent acid, it has two bonding sites with an organic group having one or more carbon atoms. For this reason, it is considered that many organic groups having one or more carbon atoms can be contained, as compared to the case where a monovalent functional group such as a carboxyl group or a cationic group is introduced into cellulose. Thereby, the surface modification of cellulose can be performed more effectively, and, for example, the compatibility with the resin can be effectively enhanced.

  (A) A group formed by covalent bonding of a phosphate group and an organic group having one or more carbon atoms is a group having one or more carbon atoms via a covalent bond to a phosphate group substituted on fine fibrous cellulose. It refers to a group in which organic groups are linked.

  Specifically, a group represented by the following formula (1) is preferable.

In formula (1), n represents an integer of 1 to n. R and R ⁿ each independently represent a hydrogen atom or an organic group having one or more carbon atoms, and at least one of R and R ⁿ represents an organic group having one or more carbon atoms. And X and X ^{n each} represents a linking group, and X and X ⁿ each independently represent a single bond or at least one selected from an ester bond, a silyl ester bond, an ether bond, a urethane bond and an amide bond It is preferable that it is a linking group containing Among them, the organic group having one or more carbon atoms is preferably bonded to the phosphate group by at least one selected from an ester bond, an ether bond and an amide bond, and is bonded to the phosphate group by the ether bond Is more preferable.

  In Formula (1), at least one R may be an organic group having one or more carbon atoms. Further, R is preferably an organic group having 10 or less carbon atoms, and more preferably 8 or less organic groups. Among them, the organic group is preferably a hydrophobic group.

  In the present invention, by mixing the surface modifier and the fine fibrous cellulose, a group formed by covalent bonding of the (a) phosphoric acid group and the organic group having one or more carbon atoms is introduced into the fine fibrous cellulose. can do. Such surface modifiers are those having compounds that can react with the hydroxyl groups of cellulose. Examples of the surface modifier include silane compounds, halogenated alkyl compounds, isocyanate compounds, epoxy compounds, acetyl compounds, amine compounds, tosylate and mesylate / analogues thereof, carboxylic acids, and vinyl resins. That is, the organic group having one or more carbon atoms is selected from silane compounds, halogenated alkyl compounds, isocyanate compounds, epoxy compounds, epoxy compounds, acetyl compounds, amine compounds, tosylate / mesylate / analogues thereof, carboxylic acids, and vinyl resins It is preferably a group derived from at least one kind, and is a group derived from at least one kind selected from silane compounds, halogenated alkylated compounds, isocyanate compounds, epoxy compounds, acetylated compounds and tosylates / mesylates and their analogues. Is more preferred.

  Examples of silane compounds include haloalkylsilanes, disilazanes, N-silylacetamides, alkoxysilanes, silyl sulfides, mercaptosilanes and octanoylthiosilanes. More specifically, as a haloalkylsilane, chlorodimethylisopropylsilane, chlorodimethylbutylsilane, chlorodimethyloctylsilane, chlorodimethyldodecylsilane, chlorodimethyloctadecylsilane, chlorodimethylphenylsilane, chloro (1-hexenyl) dimethylsilane, dichloromethane Hexylmethylsilane, dichloroheptylmethylsilane, or trichlorooctylsilane; as disilazane, hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1,3-divinyl-1,3 -Diphenyl-1,3-dimethyl-disilazane, 1,3-N-dioctyltetramethyl-disilazane, diisobutyltetramethyldisilazane, diethyltetramethyldisilazane, N-dipropyltetrame Rudisilazane, N-dibutyltetramethyldisilazane or 1,3-di (para-t-butylphenethyl) tetramethyldisilazane; as N-silylacetamide, N-trimethylsilylacetamide, N-methyldiphenylsilylacetamide, or N-triethyl ester Silylacetamide; as alkoxysilane, t-butyldiphenylmethoxysilane, octadecyldimethylmethoxysilane, dimethyloctylmethoxysilane, octylmethyldimethoxysilane, octyltrimethoxysilane, trimethylethoxysilane, or octyltriethoxysilane; as silyl sulfide; 3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxy) Silylpropyl) disulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) Tetrasulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthio Carbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate Noble sulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazolyl tetrasulfide; as mercaptosilane, 3-mercaptopropyl Trimethoxysilane, 3-Mercaptopropyltriethoxysilane, 2-Mercaptoethyltrimethoxysilane, 2-Mercaptopropyltriethoxysilane, 2-Mercaptoethyltrimethoxysilane, 2-Mercaptoethyltriethoxysilane, 3-Mercaptopropyldimethoxymethyl Silane: 3-octanoylthio-1 propyltrimethoxysilane, 3-octanoylthio-1-propyltriethoxysilane as octanoylthiosilane Mention may be made of the emissions and the like.

  When a silane compound is used as the surface modifier, the silane compound and the phosphate group react with each other to form a group (a) in which an organic group having one or more carbon atoms having a silyl phosphate ester bond is covalently bonded to the phosphate group. Will be formed.

  Examples of halogenated alkyl compounds include chloropropane, chlorobutane, bromopropane, bromohexane, bromoheptane, iodomethane, iodoethane, iodoethane, iodooctane, iodooctadecane, iodobenzene and the like.

  When a halogenated alkyl compound is used as the surface modifier, the halogenated alkyl compound reacts with the phosphoric acid group to covalently bond an organic group having one or more carbon atoms having a phosphoric acid ester bond to the phosphoric acid group ( The group of a) will be formed.

  As an isocyanate compound, butyl isocyanate, t-butyl isocyanate, pentyl isocyanate, octyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, phenyl isocyanate etc. can be mentioned.

  When an isocyanate compound is used as the surface modifier, the isocyanate compound and the phosphoric acid group react with each other to form a phosphoric acid urethane bond-containing organic group having one or more carbon atoms which is covalently bonded to the phosphoric acid group (a) Will be formed.

  As epoxy compounds, 1,2-epoxybutane, 1,2-epoxyhexane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,2-epoxydodecane, 1,2-epoxyhexadecane, 1,2 -Epoxyoctadecane or 1,2-epoxy-7-octene, methyl glycidyl ether, propyl glycidyl ether, butyl glycidyl ether, 2-methyl butyl glycidyl ether, ethylhexyl glycidyl ether, octyl glycidyl ether, lauryl glycidyl ether, allyl glycidyl ether, Examples thereof include benzyl glycidyl ether and stearyl glycidyl ether.

  When an epoxy compound is used as the surface modifier, the epoxy compound and the phosphoric acid group react with each other to form a phosphoric acid group and the organic group having one or more carbon atoms has a covalent bond to the phosphoric acid group (a) Will be formed.

As an acetylated compound, acetic anhydride and the like can be mentioned.
When an acetylated compound is used as the surface modifier, the acetylated compound reacts with the phosphoric acid group to covalently bond an organic group having one or more carbon atoms having phosphoric acid carboxylic acid anhydride to the phosphoric acid group (a) Is formed.

  Tosylate, mesylate, and their analogues include toluene sulfonic acid methane, ethane toluene sulfonic acid, propyl toluene sulfonic acid, butyl toluene sulfonic acid, methane sulfonic acid methane, ethane methane sulfonic acid, propyl methane sulfonic acid, butyl methane sulfonic acid, etc. Can be mentioned. In addition, "tosylate, mesylate and its analogue" mean that it is at least any one selected from tosylate, mesylate, analogues of tosylate and analogues of mesylate.

  When tosylate, mesylate, or an analogue thereof is used as a surface modifier, the tosylate, mesylate, an analogue thereof, and the phosphate group react with each other to form an organic group having one or more carbon atoms having a phosphoric acid ester bond. A group (a) covalently bonded to a group is to be formed.

Examples of the carboxylic acid include benzoic acid, heptanoic acid, nonanoic acid, caprylic acid, nonanoic acid, capric acid, undecylic acid, lauric acid and the like. The carboxylic acid may be a polycarboxylic acid, and examples of polycarboxylic acids include unsaturated dibasic acids and their anhydrides, and maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, chlormaleic acid There are acids and esters thereof, and examples thereof include halogenated maleic anhydride and the like, α, β-unsaturated dibasic acids such as aconitic acid and β, γ-unsaturated dibasic acids such as dihydromuconic acid. In addition, as a saturated dibasic acid and its anhydride, phthalic acid, phthalic anhydride, halogenated phthalic acid, isophthalic acid, terephthalic acid, nitrophthalic acid, tetrahydrophthalic acid, tetrahydrophthalic anhydride, endo methylene tetrahydrophthalic anhydride, There are halogenated phthalic anhydride and esters thereof, etc., and hexahydrophthalic acid, hexahydrophthalic anhydride, hexahydroterephthalic acid, hexahydroisophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, methyl Hexahydrophthalic acid, head acid, 1,1-cyclobutanedicarboxylic acid, oxalic acid, succinic acid, succinic anhydride, malonic acid, glutaric acid, glutaric acid, adipic acid, azelaic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid , 1,12 Acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid anhydride, 4,4'-biphenyl dicarboxylic acid, A dialkyl ester etc. are mentioned.
The carboxylic acid may be a hydroxycarboxylic acid, and as the hydroxycarboxylic acid, lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 2-hydroxy 3, 3-dimethyl butyric acid, 2-hydroxy -3- methylbutyric acid, 2-hydroxyisocaproic acid, p-hydroxybenzoic acid and the like.

  When a carboxylic acid is used as the surface modifier, the carboxylic acid and the phosphoric acid group react with each other to covalently bond the organic group having one or more carbon atoms having phosphoric acid carboxylic acid anhydride to the phosphoric acid group (a) Is formed.

Examples of vinyl resins include polymers or copolymers of vinyl monomers. Examples of the vinyl monomer include (meth) acrylic acid ester derivatives, vinyl ester derivatives, maleic acid diester derivatives, fumaric acid diester derivatives, (meth) acrylamide derivatives, styrene derivatives, vinyl ether derivatives, vinyl ketone derivatives, olefin derivatives, maleimide derivatives, Acrylonitrile and the like. The vinyl resin is preferably a (meth) acrylic resin obtained by polymerizing a (meth) acrylic acid ester derivative.
Examples of (meth) acrylic acid ester derivatives include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate , Isobutyl (meth) acrylate, t-butyl (meth) acrylate, amyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, t-octyl (meth) acrylate, dodecyl (meth) acrylate, octadecyl (meth) acrylate, acetoxyethyl (meth) acrylate, phenyl (meth) acrylate, (meth) 2-Hydroxyethyl acrylate, 2-Hydroxypropyl (meth) acrylate, (Meth) acrylic acid 3-hydroxypropyl, (meth) acrylic acid 4-hydroxybutyl, (meth) acrylic acid 2-methoxyethyl, (meth) acrylic acid 2-ethoxyethyl, (meth) acrylic acid 2- (2) -Methoxyethoxy) ethyl, 3-phenoxy-2-hydroxypropyl (meth) acrylate, 2-chloroethyl (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylic acid-3,4-epoxycyclohexylmethyl (Vinyl) (meth) acrylate, (meth) acrylic acid 2-phenylvinyl, (meth) acrylic acid 1-propenyl, allyl (meth) acrylate, (meth) acrylic acid 2-allyloxyethyl (meth ) Propargyl acrylate, benzyl (meth) acrylate, diethylene glycol (meth) acrylate Monomethyl ether, (meth) acrylic acid diethylene glycol monoethyl ether, (meth) acrylic acid triethylene glycol monomethyl ether, (meth) acrylic acid triethylene glycol monoethyl ether, (meth) acrylic acid polyethylene glycol monomethyl ether, (meth) acrylic Acid polyethylene glycol monoethyl ether, (meth) acrylic acid β-phenoxyethoxyethyl, (meth) acrylic acid nonyl phenoxy polyethylene glycol, (meth) acrylic acid dicyclopentenyl, (meth) acrylic acid dicyclopentenyl oxyethyl (meth ) Trifluoroethyl acrylate, Octafluoropentyl (meth) acrylate, Perfluorooctylethyl (meth) acrylate, Dicyclopentanone (meth) acrylate , (Meth) acrylic acid tribromophenyl, (meth) tribromophenyl oxyethyl acrylate, and (meth)-.gamma.-butyrolactone acrylate.
Examples of vinyl ester derivatives include vinyl acetate, vinyl chloroacetate, vinyl propionate, vinyl butyrate, vinyl methoxyacetate, and vinyl benzoate and the like.
Examples of maleic acid diester derivatives include dimethyl maleate, diethyl maleate, and dibutyl maleate and the like.
Examples of fumaric acid diester derivatives include dimethyl fumarate, diethyl fumarate, and dibutyl fumarate. Examples of itaconic acid diester derivatives include dimethyl itaconate, diethyl itaconate, and dibutyl itaconate.
Examples of (meth) acrylamide derivatives include (meth) acrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-n -Butyl acrylic (meth) amide, N-t-butyl (meth) acrylamide, N-cyclohexyl (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N N-diethyl (meth) acrylamide, N-phenyl (meth) acrylamide, N-nitrophenyl acrylamide, N-ethyl-N-phenyl acrylamide, N-benzyl (meth) acrylamide, (meth) acryloyl morpholine, diacetone acrylamide, N- Ji acrylamide, N- hydroxyethyl acrylamide, vinyl (meth) acrylamide, N, N- diallyl (meth) acrylamide, N- allyl (meth) acrylamide.
Examples of styrene derivatives include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, hydroxystyrene, methoxystyrene, butoxystyrene, acetoxystyrene, chlorostyrene, dichlorostyrene, bromostyrene and chloromethyl Styrene, α-methylstyrene and the like can be mentioned.
Examples of vinyl ether derivatives include methyl vinyl ether, ethyl vinyl ether, 2-chloroethyl vinyl ether, hydroxyethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, octyl vinyl ether, methoxyethyl vinyl ether and phenyl vinyl ether.
Examples of vinyl ketone derivatives include methyl vinyl ketone, ethyl vinyl ketone, propyl vinyl ketone, phenyl vinyl ketone and the like.
Examples of olefin derivatives include ethylene, propylene, isobutylene, butadiene, isoprene and the like.
Examples of maleimide derivatives include maleimide, butyl maleimide, cyclohexyl maleimide, phenyl maleimide and the like.
Besides, (meth) acrylonitrile, heterocyclic group substituted with a vinyl group (for example, vinylpyridine, N-vinylpyrrolidone, vinylcarbazole etc.), N-vinylformamide, N-vinylacetamide, N-vinylimidazole, vinyl It is also possible to use caprolactone etc.

  The vinyl resin preferably has a functional group. Specific examples of the functional group include a halogen group (fluorine, chlorine), a hydroxyl group, a carboxyl group, an amino group, a silanol group, a cyano group and the like, and these may have a plurality of types. In addition, the vinyl resin may be a straight chain polymer or a branched polymer, and in the case of a branched polymer, it may be comb-shaped or star-shaped.

  When a vinyl resin is used as the surface modifier, the vinyl resin and the phosphoric acid group react with each other to form a phosphoric acid group and the organic group having one or more carbon atoms having a phosphoric acid ester bond is covalently bonded to the phosphoric acid group. Will be formed.

  As the amine compound, an amine having an EO / PO copolymer, an amine having an aromatic ring (aryl group), an amine having an aromatic ring (aralkyl group), an amine having a PO polymer, an alkyl group (C1 to 30) And secondary amines having an alkyl group (C1 to 30), amines having an alicyclic alkyl group, and the like. In addition, an EO / PO copolymer part means the structure which ethylene oxide (EO) and propylene oxide (PO) superposed | polymerized at random or block shape.

  When an amine compound is used as the surface modifier, the amine compound and the phosphoric acid group react with each other to form a phosphoric acid amide bond-containing organic group having one or more carbon atoms which is covalently bonded to the phosphoric acid group (a) Will be formed.

<Other ingredients>
The fine fibrous cellulose content may contain other components in addition to the fine fibrous cellulose. Examples of other components include water-soluble polymers and surfactants. Examples of water-soluble polymers include synthetic water-soluble polymers (eg, carboxyvinyl polymer, polyvinyl alcohol, alkyl methacrylate / acrylic acid copolymer, polyvinyl pyrrolidone, sodium polyacrylate, polyethylene glycol, diethylene glycol, triethylene glycol, polyethylene oxide, Propylene glycol, dipropylene glycol, polypropylene glycol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, polyacrylamide etc., polysaccharide thickeners (eg, xanthan gum, guar gum, tamarind gum, carrageenan, locust bean gum, quinusin gum Seed, alginic acid, pullulan, carrageenan, pectin etc), cellulose derivatives (eg carboxymethyl cellulose Starch, raw starch, raw starch, oxidized starch, etherified starch, esterified starch, esterified starch, starch such as amylose, glycerin such as glycerin, diglycerin and polyglycerin, hyaluronic acid Acids, metal salts of hyaluronic acid and the like can be mentioned. Moreover, as surfactant, nonionic surfactant, anionic surfactant, and cationic surfactant can be used.

(Fine fibrous cellulose)
The fibrous cellulose raw material for obtaining the fine fibrous cellulose is not particularly limited, but it is preferable to use pulp in terms of availability and low cost. The pulp may include wood pulp, non-wood pulp and deinked pulp. As wood pulp, for example, hardwood kraft pulp (LBKP), softwood kraft pulp (NBKP), sulfite pulp (SP), dissolving pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP), oxygen bleached kraft Chemical pulp, such as pulp (OKP), etc. are mentioned. In addition, semichemical pulp such as semichemical pulp (SCP), chemiground wood pulp (CGP), mechanical pulp such as ground pulp (GP), thermomechanical pulp (TMP, BCTMP), etc. may be mentioned, but it is not particularly limited. Non-wood pulps include cotton-based pulps such as cotton linters and cotton lint, non-wood-based pulps such as hemp, straw and bagasse, celluloses isolated from ascidians and seaweeds, chitin, chitosan and the like, but are not particularly limited . Examples of the deinked pulp include, but not particularly limited to, deinked pulp made from waste paper. The pulp of this embodiment may be used singly or in combination of two or more. Among the above-mentioned pulps, wood pulps containing cellulose and deinked pulps are preferable in terms of availability. Among wood pulps, chemical pulp has a large cellulose ratio, so the yield of fine fibrous cellulose is high at the time of fiber refining (fibrillation), and decomposition of cellulose in the pulp is small, and fine fibers of long fibers having a large axial ratio It is preferable at the point from which fibrous cellulose is obtained. Among them, kraft pulp and sulfite pulp are most preferably selected. A sheet containing fine fibrous cellulose of long fibers with a large axial ratio tends to obtain high strength.

  The average fiber width of the fine fibrous cellulose is 1000 nm or less as observed by an electron microscope. The average fiber width is preferably 2 to 1000 nm, more preferably 2 to 100 nm, more preferably 2 to 50 nm, and still more preferably 2 to 10 nm, but is not particularly limited. If the average fiber width of the fine fibrous cellulose is less than 2 nm, it dissolves in water as cellulose molecules, so the physical properties (strength, rigidity, and dimensional stability) as the fine fibrous cellulose tend to be difficult to express . The fine fibrous cellulose is, for example, monofibrillar cellulose having a fiber width of 1000 nm or less.

  The measurement of the average fiber width by electron microscopic observation of fine fibrous cellulose is performed as follows. An aqueous suspension of fine fibrous cellulose having a concentration of 0.05 to 0.1% by mass is prepared, and the suspension is cast on a hydrophilized carbon film-coated grid to prepare a sample for TEM observation. If wide fibers are included, an SEM image of the surface cast on glass may be observed. Observation with an electron microscope image is performed at a magnification of 1000 times, 5000 times, 10000 times or 50000 times depending on the width of the fiber to be constructed. However, the sample, observation conditions and magnification are adjusted to satisfy the following conditions.

(1) One straight line X is drawn at an arbitrary position in the observation image, and 20 or more fibers cross the straight line X.
(2) Draw a straight line Y intersecting perpendicularly with the straight line in the same image, and 20 or more fibers cross the straight line Y.

  With respect to the observation image satisfying the above conditions, the width of the fiber intersecting with the straight line X and the straight line Y is visually read. Thus, three or more sets of images of at least non-overlapping surface portions are observed, and for each image, the width of the fiber intersecting the straight line X and the straight line Y is read. Thus, a fiber width of at least 20 x 2 x 3 = 120 is read. The average fiber width (sometimes simply referred to as "fiber width") of fine fibrous cellulose is the average value of the fiber widths read in this manner.

  The fiber length of the fine fibrous cellulose is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 0.1 to 800 μm, and particularly preferably 0.1 to 600 μm. By setting the fiber length within the above range, it is possible to suppress the destruction of the crystalline region of the fine fibrous cellulose and to make the slurry viscosity of the fine fibrous cellulose into an appropriate range. In addition, the fiber length of fine fibrous cellulose can be calculated | required from the image analysis by TEM, SEM, and AFM.

The fine fibrous cellulose preferably has a type I crystal structure. Here, the fact that the fine fibrous cellulose has an I-type crystal structure can be identified in a diffraction profile obtained from a wide-angle X-ray diffraction photograph using CuKα (λ = 1.5418 Å) monochromatized with graphite. Specifically, it can be identified from having typical peaks at two positions near 2θ = 14 ° to 17 ° and 2θ = 22 ° to 23 °.
The proportion of crystal form I in fine fibrous cellulose is preferably 30% or more, more preferably 50% or more, and still more preferably 70% or more.

  Although the ratio of the crystal parts contained in the fine fibrous cellulose is not particularly limited in the present invention, it is preferable to use cellulose having a crystallinity of 60% or more as determined by X-ray diffraction. The degree of crystallinity is preferably 65% or more, more preferably 70% or more. In this case, further excellent performance can be expected in terms of heat resistance and low linear thermal expansion. With regard to the degree of crystallinity, the X-ray diffraction profile is measured, and the pattern is determined by a conventional method (Seagal et al., Textile Research Journal, 29: 786, 1959).

<Phosphorylation treatment>
In the present invention, the fine fibrous cellulose has (a) a group formed by covalent bonding of a phosphate group and an organic group having one or more carbon atoms, and (b) an organic group having one or more carbon atoms. Have no phosphate group. The group (a) is introduced by reacting the above-mentioned surface modifier with the phosphoric acid group introduced to the fine fibrous cellulose. The group (b) is a group in which an organic group having one or more carbon atoms is not bonded to a phosphoric acid group, and refers to the phosphoric acid group itself introduced into the fine fibrous cellulose. Both the group of (a) and the group of (b) are obtained through the steps of phosphorylating the fiber material and the step of reacting the surface modifier.

  In the phosphorylation treatment step (hereinafter, also referred to as a phosphate group introducing step), a compound having a phosphate group and / or a salt thereof (hereinafter, referred to as "compound A") for the fiber raw material obtained through the above steps The reaction can be carried out by reacting This reaction may be carried out in the presence of urea and / or a derivative thereof (hereinafter referred to as "compound B"), thereby efficiently introducing a phosphate group to the hydroxyl group of the fine fibrous cellulose. Can.

  The phosphate group introducing step necessarily includes a step of introducing a phosphate group into cellulose, and may optionally include an alkali treatment step described later, a step of washing an excess reagent, and the like.

  As an example of the method of allowing compound A to act on the fiber material in the coexistence of compound B, a method of mixing powder or an aqueous solution of compound A and compound B with a dry or wet fiber material can be mentioned. Another example is a method of adding a powder or an aqueous solution of the compound A and the compound B to a slurry of a fiber material. Among them, the method of adding the aqueous solution of compound A and compound B to the fiber material in the dry state or adding the powder or the aqueous solution of compound A and compound B to the fiber material in the wet state because of high uniformity of reaction The method is preferred. Compound A and Compound B may be added simultaneously or separately. Alternatively, the compound A and the compound B to be tested first may be added as an aqueous solution, and excess chemical solution may be removed by pressing. The form of the fiber material is preferably cotton-like or thin sheet, but is not particularly limited.

The compound A used in the present embodiment is a compound having a phosphate group and / or a salt thereof.
Examples of the compound having a phosphate group include phosphoric acid, lithium salts of phosphoric acid, sodium salts of phosphoric acid, potassium salts of phosphoric acid, ammonium salts of phosphoric acid and the like, but are not particularly limited. Examples of lithium salts of phosphoric acid include lithium dihydrogen phosphate, dilithium hydrogen phosphate, trilithium phosphate, lithium pyrophosphate, lithium polyphosphate and the like. Examples of sodium salts of phosphoric acid include sodium dihydrogenphosphate, disodium hydrogenphosphate, trisodium phosphate, sodium pyrophosphate, sodium polyphosphate and the like. Examples of potassium salts of phosphoric acid include potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, and potassium polyphosphate. Examples of ammonium salts of phosphoric acid include ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, ammonium polyphosphate and the like.

  Among them, phosphoric acid and sodium of phosphoric acid from the viewpoint of high efficiency of phosphate group introduction, easy to improve the fibrillation efficiency in the fibrillation step to be described later, low cost, and easy industrial application. Salts or potassium salts of phosphoric acid and ammonium salts of phosphoric acid are preferred. Sodium dihydrogen phosphate or disodium hydrogen phosphate is more preferred.

  In addition, it is preferable to use Compound A as an aqueous solution because the uniformity of the reaction is enhanced and the efficiency of introducing a phosphate group is enhanced. The pH of the aqueous solution of compound A is not particularly limited, but is preferably 7 or less because the efficiency of phosphate group introduction increases, and is preferably 3 to 7 from the viewpoint of suppressing hydrolysis of pulp fibers. The pH of the aqueous solution of the compound A may be adjusted by, for example, using a compound having a phosphoric acid group in combination of a compound exhibiting acidity and a compound exhibiting alkalinity, and changing its quantitative ratio. The pH of the aqueous solution of the compound A may be adjusted by adding an inorganic alkali or an organic alkali to a compound having an acid group among the compounds having a phosphoric acid group.

  The amount of compound A added to the fiber material is not particularly limited, but when the amount of compound A added is converted to the phosphorus atomic weight, the amount of phosphorus atom added to the fiber material is preferably 0.5 to 100% by mass, and 1 to 50 mass. % Is more preferable, and 2 to 30% by mass is the most preferable. If the addition amount of phosphorus atoms to the fiber raw material is within the above range, the yield of fine fibrous cellulose can be further improved. When the addition amount of phosphorus atoms to the fiber raw material exceeds 100% by mass, the effect of improving the yield becomes flat and the cost of the compound A used is increased. On the other hand, the yield can be increased by setting the addition amount of phosphorus atoms to the fiber raw material to the above lower limit value or more.

  As compound B used in this embodiment, urea, thiourea, biuret, phenylurea, benzylurea, dimethylurea, diethylurea, tetramethylurea, benzoleinurea, hydantoin and the like can be mentioned. Among these, urea is preferable because it is easy to handle at low cost and it is easy to form a hydrogen bond with a fiber material having a hydroxyl group.

  The compound B is preferably used as an aqueous solution like the compound A. Further, it is preferable to use an aqueous solution in which both the compound A and the compound B are dissolved, because the uniformity of the reaction is enhanced. It is preferable that the addition amount of the compound B with respect to a fiber raw material is 1-300 mass%.

  In addition to the compound A and the compound B, amides or amines may be included in the reaction system. Examples of the amides include formamide, dimethylformamide, acetamide, dimethylacetamide and the like. Examples of amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, hexamethylenediamine and the like. Among these, triethylamine is known to work as a good reaction catalyst.

  It is preferable to heat-process in a phosphoric acid group introduction process. As the heat treatment temperature, it is preferable to select a temperature at which the phosphoric acid group can be efficiently introduced while suppressing the thermal decomposition or hydrolysis reaction of the fiber. Specifically, the temperature is preferably 50 to 250 ° C, and more preferably 100 to 200 ° C. For heating, a vacuum dryer, an infrared heater, or a microwave heater may be used.

  During the heat treatment, while the fiber material slurry to which Compound A is added contains water, if the time for which the fiber material is allowed to stand becomes long, Compound A, which is dissolved with water molecules, moves to the surface of the fiber material as it dries. Do. Therefore, unevenness may occur in the concentration of the compound A in the fiber raw material, and there is a possibility that the introduction of the phosphate group to the fiber surface may not progress uniformly. In order to suppress the occurrence of uneven concentration of compound A in the fiber material due to drying, a very thin sheet-like fiber material is used, or the fiber material and compound A are kneaded or / and stirred with a kneader etc. A method of drying may be employed.

The heating device used for the heat treatment is preferably a device capable of constantly discharging the water held by the slurry and the water produced by the addition reaction to the hydroxyl groups of the fibers such as phosphoric acid groups, for example, an air-blowing oven. Etc. is preferred. In addition to the fact that hydrolysis of the phosphate ester bond, which is the reverse reaction of phosphorylation, can be suppressed by constantly draining the water in the system, acid hydrolysis of sugar chains in fibers can also be suppressed. And fine fibers with high axial ratio can be obtained.
The heat treatment time is also influenced by the heating temperature, but is preferably 1 to 300 minutes, and more preferably 1 to 200 minutes, after the water content is substantially removed from the fiber material slurry. It is not limited.

  In addition, in the phosphate group introducing step, the reaction is performed so that the difference between the introduction amounts of the strongly acidic group and the weakly acidic group derived from the phosphate group introduced into the cellulose is 0.5 mmol / g or less, which is highly transparent. It is preferable to obtain fine fibrous cellulose. The difference between the introduction amount of the strongly acidic group and the weakly acidic group derived from the phosphoric acid group is more preferably 0.3 mmol / g or less, and particularly preferably 0.2 mmol / g or less. preferable.

  The phosphate group introduction step may be performed at least once, but can be repeated multiple times. In this case, more phosphate groups are introduced, which is preferable.

<Introduction amount of phosphate group>
The amount of phosphate group introduced is preferably 0.1 to 3.5 mmol / g per 1 g (mass) of fine fibrous cellulose, more preferably 0.14 to 2.5 mmol / g, and more preferably 0.2 to 2 And more preferably 0.2 to 1.8 mmol / g, particularly preferably 0.4 to 1.8 mmol / g, and most preferably 0.6 to 1.8 mmol / g. By making the introduction amount of the phosphate group within the above range, it is possible to facilitate the miniaturization of the fiber raw material and to enhance the stability of the fine fibrous cellulose. Moreover, the viscosity of the slurry of fine fibrous cellulose can be adjusted in an appropriate range by making the introduction amount of a phosphoric acid group into the said range.

  The amount of phosphate group introduced into the fiber material can be measured by the above-mentioned conductivity titration method. Specifically, the fineness is carried out by the defibration treatment step, and the obtained fine fibrous cellulose-containing slurry is treated with an ion exchange resin, and then the change in electric conductivity is obtained while adding an aqueous solution of sodium hydroxide, The introduced amount can be measured.

<Alkali treatment>
In the case of producing fine fibrous cellulose, alkali treatment can be performed between the phosphorylation treatment step and the defibration treatment step described later. Although it does not specifically limit as the method of an alkali treatment, For example, the method of immersing phosphate group introduction | transduction fiber in an alkali solution is mentioned.
The alkaline compound contained in the alkaline solution is not particularly limited, but may be an inorganic alkaline compound or an organic alkaline compound. The solvent in the alkaline solution may be either water or an organic solvent. The solvent is preferably a polar solvent (water or a polar organic solvent such as alcohol), more preferably an aqueous solvent containing at least water.
Among the alkali solutions, sodium hydroxide aqueous solution or potassium hydroxide aqueous solution is particularly preferable because of high versatility.

The temperature of the alkaline solution in the alkaline treatment step is not particularly limited, but is preferably 5 to 80 ° C, and more preferably 10 to 60 ° C.
Although the immersion time in the alkaline solution in an alkali treatment process is not specifically limited, 5 to 30 minutes are preferable and 10 to 20 minutes are more preferable.
Although the usage-amount of the alkaline solution in alkali treatment is not specifically limited, It is preferable that it is 100-100000 mass% with respect to the absolute dry mass of a phosphoric acid group introduction | transduction fiber, and it is more preferable that it is 1000-10000 mass%.

  In order to reduce the amount of alkali solution used in the alkali treatment step, the phosphate group-introduced fiber may be washed with water or an organic solvent before the alkali treatment step. After the alkali treatment, in order to improve the handleability, it is preferable to wash the alkali-treated phosphate group-introduced fiber with water or an organic solvent before the defibration treatment step.

<Disintegration processing>
The phosphate group-introduced fiber is subjected to disintegration processing in a disintegration processing step. In the defibration treatment step, fibers are usually defibrated using a defibration treatment device to obtain a fine fibrous cellulose-containing slurry, but the treatment device and treatment method are not particularly limited.
As the defibration processing apparatus, a high-speed fibrillation machine, a grinder (millstone type crusher), a high pressure homogenizer, an ultrahigh pressure homogenizer, a high pressure collision type crusher, a ball mill, a bead mill, etc. can be used. Alternatively, use an apparatus for wet grinding such as a disc refiner, a conical refiner, a twin screw kneader, a vibration mill, a homomixer under high speed rotation, an ultrasonic disperser, or a beater as a defibration treatment apparatus. You can also. The defibration processing apparatus is not limited to the above. As a preferable defibration treatment method, a high-speed fibrillation machine, a high pressure homogenizer, and an ultrahigh pressure homogenizer, which are less affected by the grinding media and less likely to be contaminated, can be mentioned.

  At the time of the defibration treatment, it is preferable to dilute the fiber raw material with water and an organic solvent singly or in combination to form a slurry, but is not particularly limited. As the dispersion medium, polar organic solvents can be used in addition to water. Preferred polar organic solvents include, but are not particularly limited to, alcohols, ketones, ethers, dimethylsulfoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMAc). As alcohols, methanol, ethanol, n-propanol, isopropanol, n-butanol, or t-butyl alcohol etc. are mentioned. Examples of ketones include acetone or methyl ethyl ketone (MEK). Examples of ethers include diethyl ether or tetrahydrofuran (THF). The dispersion medium may be one type, or two or more types. The dispersion medium may also contain solid components other than the fiber material, such as urea having hydrogen bonding property.

  In the present invention, the fibrillation treatment may be carried out after concentrating and drying the fine fibrous cellulose. In this case, the method of concentration and drying is not particularly limited, and examples thereof include a method of adding a thickener to a slurry containing fine fibrous cellulose, a method of using a generally used dehydrator, a press, and a dryer. Also, known methods can be used, such as the methods described in WO2014 / 024876, WO2012 / 107642, and WO2013 / 121086. Alternatively, concentrated fine fibrous cellulose may be sheeted. The sheet can also be crushed and subjected to disintegration processing.

  As an apparatus used for pulverizing fine fibrous cellulose, a high-speed fibrillation machine, a grinder (stone mill type crusher), a high pressure homogenizer, an ultra high pressure homogenizer, a high pressure collision type crusher, a ball mill, a bead mill, a disc type refiner, a conical An apparatus for wet grinding such as a refiner, a twin screw kneader, a vibration mill, a homomixer under high speed rotation, an ultrasonic dispersion machine, a beater, etc. can also be used, but is not particularly limited.

  The fine fibrous cellulose having a phosphate group obtained by the method described above is a fine fibrous cellulose-containing slurry (fine fibrous cellulose dispersion), and may be diluted with water so as to have a desired concentration. . That is, the fine fibrous cellulose-containing substance of the present invention may be a fine fibrous cellulose-containing slurry. In this case, the content of the fine fibrous cellulose contained in the fine fibrous cellulose-containing slurry is preferably 0.1 to 5.0% by mass with respect to the total mass of the fine fibrous cellulose-containing substance, and 0. The content is more preferably 3 to 3.0% by mass, and still more preferably 0.5 to 3.0% by mass.

<Introduction of organic group to fine fibrous cellulose>
An organic group having one or more carbon atoms is introduced into part of the fine fibrous cellulose having a phosphate group. The introduction of such an organic group is carried out by mixing a fine fibrous cellulose having a phosphate group with a surface modifier having a compound capable of reacting with the hydroxyl group of cellulose. In the step of introducing the organic group into the fine fibrous cellulose, it is preferable to use a solvent according to the compound capable of reacting with the hydroxyl group of the cellulose, and prior to the step of mixing the surface modifier, It is preferable to provide a step of replacing the solvent. In addition, the step of mixing the surface modifier may be a step of applying the surface modifier to the sheeted fine fibrous cellulose, and in such a case, before the step of mixing the surface modifier. A step of obtaining a sheet of fine fibrous cellulose may be provided.

  The solvent can be appropriately selected depending on the surface modifier to be used. As the solvent, for example, ethanol, isopropyl alcohol (IPA), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N, N-dimethylacetamide, tetrahydrofuran (THF), succinic acid and triethylene glycol monomethyl ether And diesters, acetone, methyl ethyl ketone (MEK), acetonitrile, dichloromethane, chloroform, toluene, acetic acid, pyridine and the like, and one of these may be used alone or in combination of two or more.

  From the viewpoint of reactivity, the amount of the compound capable of reacting with the hydroxyl group of cellulose is preferably 0.1 mol or more per 1 mol of phosphoric acid group contained in the phosphoric acid group-containing fine fibrous cellulose, It is more preferably 0.5 mol or more, further preferably 1 mol or more. The surface modifier may be subjected to the reaction at one time or may be divided and subjected to the reaction.

  The mixing temperature when mixing the phosphate group-containing fine fibrous cellulose and the surface modifier is preferably 10 ° C. or more, more preferably 20 ° C. or more, and still more preferably 30 ° C. or more. Moreover, it is preferable that mixing temperature is 150 degrees C or less. The mixing time can be appropriately set according to the type of surface modifier and solvent used, but is preferably 1 hour or more, more preferably 2 hours or more, and 3 hours or more. More preferable.

  After the mixing step, it is preferable to carry out post-treatment as appropriate. As a post-treatment method, for example, washing, filtration, centrifugation, dialysis and the like can be used.

  As described above, (a) a group formed by covalent bonding of a phosphate group and an organic group having one or more carbon atoms, and (b) a phosphate group having no organic group having one or more carbon atoms And can be obtained.

  As described above, the production process of the fine fibrous cellulose-containing substance of the present invention includes a phosphoric acid group introducing process, a fibrillation process, and an organic group introducing process in this order. The fibrillation step is a step of obtaining fine fibrous cellulose having a phosphate group. The organic group introduction step is a step of reacting the fine fibrous cellulose with the surface modifier. If necessary, a step of obtaining a sheet of fine fibrous cellulose may be provided before the organic group introducing step.

(Fine fibrous cellulose-containing resin composition)
The present invention may be directed to a fine fibrous cellulose-containing resin composition containing the above-described fine fibrous cellulose-containing substance. The fine fibrous cellulose-containing resin composition contains a fine fibrous cellulose-containing substance and a resin. In the present invention, the fine fibrous cellulose has (a) a group formed by covalent bonding of a phosphate group and an organic group having one or more carbon atoms, and (b) an organic group having one or more carbon atoms. Since the fine fibrous cellulose-containing material is excellent in compatibility with the resin because it has no phosphoric acid group, a fine fibrous cellulose-containing resin composition having high transparency can be obtained.

  The resin contained in the fine fibrous cellulose-containing resin composition may be a thermoplastic resin, a thermosetting resin (a cured product obtained by polymerizing and curing a precursor of a thermosetting resin by heating), or a photocurable resin (photocurable) Examples thereof include a cured product obtained by polymerizing and curing a resin precursor by irradiation with radiation (ultraviolet light, electron beam, etc.).

  The thermoplastic resin is not particularly limited. For example, an olefin resin (eg, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, etc.) ), Polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, poly (meth) acrylic acid alkyl ester polymer or copolymer, styrenic resin (eg, polystyrene, styrene-acrylonitrile copolymer, styrene- (meth) acrylic) Acid alkyl ester copolymer, ABS resin), polyester resin (eg, polyethylene terephthalate, polybutylene terephthalate, polylactic acid, polybutylene succinate, unsaturated polyester etc.), polyurethane, natural rubber, styrene-butadiene copolymer, A Cryronitrile-butadiene copolymer, polyisoprene, polychloroprene, styrene-butadiene-methyl methacrylate copolymer, polyvinyl alcohol, ethylene-vinyl acetate copolymer saponification, polyamide based resin (for example, nylon 6, nylon 66, nylon) 10, nylon 11, nylon 12, nylon 610, polymethaxylylene adipamide, etc.), polycarbonate, polyacetal, polyphenylene oxide, fluorine resin and the like. These thermoplastic resins may be used alone or in combination of two or more.

  The thermosetting resin is not particularly limited, but epoxy resin, acrylic resin, oxetane resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, silicone resin, polyurethane resin, silsesquioxane resin Or diallyl phthalate resin and the like.

  Although it does not specifically limit as a photocurable resin, The epoxy resin, the acrylic resin, silsesquioxane resin, or oxetane resin etc. which were illustrated as the above-mentioned thermosetting resin are mentioned.

  Furthermore, as a specific example of a thermoplastic resin, a thermosetting resin, or a photocurable resin, the thing as described in Unexamined-Japanese-Patent No. 2009-299043 is mentioned.

(Fine fibrous cellulose-containing resin molded product)
Furthermore, the present invention may relate to a fine fibrous cellulose-containing resin molded product obtained by molding the above-described fine fibrous cellulose-containing resin composition. In the present invention, since the fine fibrous cellulose-containing substance excellent in compatibility with the resin is used, the fine fibrous cellulose-containing resin molded product has an excellent flexural modulus. In addition, the fine fibrous cellulose-containing resin molded product is also excellent in transparency.

  There is no restriction | limiting in particular in the shaping | molding method of a fine fibrous cellulose containing resin molding, The injection molding method, the heat-press molding method, etc. are employable.

In order to improve the compatibility of the fine fibrous cellulose-containing substance with the resin described above, for example, after the fine fibrous cellulose-containing substance is sheeted, the fine fibrous cellulose-containing substance sheet is pulverized and mixed with the resin Also good.
In the pulverizing step, known pulverizers such as a sample mill, a hammer mill, a turbo mill, an atomizer, a cutter mill, a bead mill, a ball mill, a roll mill, a jet mill and the like can be used. Further, it may be crushed using a shredder.
After grinding, a screen may be used to screen the shape and size of the ground material. By sieving, the dispersibility to the above-mentioned resin can be made higher. The diameter of the screen used for sieving is preferably 0.5 to 10 mm, more preferably 1 to 8 mm. If the diameter of the screen is equal to or more than the above lower limit, the ground material is easily produced. If it is less than the above-mentioned upper limit, compatibility with the above-mentioned resin will become high.

  The shape of the resin to be mixed with the pulverized product of the fine fibrous cellulose-containing material sheet is not particularly limited, and may be, for example, pellet, granule, powder or fiber. From the viewpoint of handleability, the resin is preferably in the form of pellets.

As a mixing method, a method of stirring the pulverized material of the fine fibrous cellulose-containing material sheet and the resin using a mixer is preferable. As a mixer, a tumbler mixer, a super mixer, a super floater, a Henschel mixer etc. can be used, for example.
If it is a small amount, the pulverized product of the fine fibrous cellulose-containing material sheet and the resin may be manually stirred and mixed.

Moreover, a well-known method is employable as the mixing method of a fine fibrous cellulose containing material and resin mentioned above. For example, melt kneading is preferably performed using a kneader or the like.
In the case of melt-kneading, kneaders such as an extruder (single-screw extruder, twin-screw extruder), a kneader, and a Banbury mixer can be used. Among them, an extruder is preferable in that it can be continuously kneaded.

  The heating temperature in the melt-kneading step is determined depending on the ease of melting of the resin, but is usually in the range of 100 to 300 ° C., and more preferably in the range of 120 to 280 ° C. If the heating temperature is equal to or higher than the lower limit, the resin is easily melted, cellulose fibers are easily dispersed in the resin, and if it is equal to or lower than the upper limit, thermal deterioration of each component can be suppressed.

After melt-kneading, it can be molded or processed into a shape (for example, pellet, sheet, tube, rod, column, etc.) according to the purpose of use of the molded body.
For example, in the case of forming a molded body into a pellet form, after melt-kneading, a strand is formed, and the strand is cut into a pellet form using a pelletizer. Pellet-like shaped bodies can be used as materials for further shaping. For example, a pellet-like molded body can be molded by a molding machine (for example, an injection molding machine, an extrusion molding machine, etc.).
When making a molded object into a sheet form, it can be made into a sheet form by discharging molten resin from a slit-like hole after melt-kneading. The sheet-like formed body may be further formed by a press forming method or a vacuum forming method.
When making a molded object into a tube shape, it can be made into a tube shape by discharging molten resin from an annular hole after melt-kneading.
When making a molded object into rod shape or columnar shape, it can be made rod shape or columnar shape by discharging molten resin from a hole after melt-kneading.

(Form of fine fibrous cellulose content)
The fine fibrous cellulose-containing substance of the present invention may be a liquid such as a slurry, or may be a powdery substance. The fine fibrous cellulose-containing material may be a sheet-like material.

  When the fine fibrous cellulose-containing substance is a fine fibrous cellulose-containing granular material, the fine fibrous cellulose-containing substance is composed of a powdery and / or granular substance. Here, the powdery substance is smaller than the particulate substance. Generally, the powdery substance refers to fine particles having a particle size of 1 nm or more and less than 0.1 mm, and the particulate substance refers to particles having a particle size of 0.1 to 10 mm, but is not particularly limited. The particle diameter of the powder can be measured and calculated using a laser diffraction method. Specifically, it is a value measured using a laser diffraction / scattering particle size distribution measuring device (Microtrac 3300 EXII, Nikkiso Co., Ltd.).

  When the fine fibrous cellulose-containing substance is a fine fibrous cellulose-containing granular material, the production method may be a known production method. For example, an oven drying method or a spray drying method can be employed.

  The fine fibrous cellulose-containing material may be a sheet-like material formed by coating or paper-making a fine fibrous cellulose-containing slurry. Further, it may be mixed with a matrix resin or the like to form a fine fibrous cellulose-containing composite sheet. Such a fine fibrous cellulose-containing composite sheet may be a sheet in which fine fibrous cellulose and a matrix resin are integrated.

  The fine fibrous cellulose-containing composite sheet may be a laminate in which the fine fibrous cellulose-containing sheet as described above and a sheet composed of a matrix resin are laminated. As a matrix resin, for example, a thermoplastic resin, a thermosetting resin (a cured product obtained by polymerizing and curing a precursor of a thermosetting resin by heating), or a photocurable resin (a precursor of a photocurable resin) And the like) and the like.

An inorganic membrane may be further laminated on the surface of the fine fibrous cellulose-containing composite sheet. As the inorganic material constituting an inorganic film, e.g., platinum, silver, aluminum, gold, or a metal such as copper, _{silicon, ITO, SiO 2, SiN,} SiOxNy, ZnO , etc., or TFT, and the like.

(Use)
The use of the fine fibrous cellulose-containing material according to the present invention is not particularly limited. As an example, it can form into a film using a fine fibrous cellulose containing slurry, and can be used as various films. As another example, the fine fibrous cellulose-containing slurry can be used as a thickener for various applications (eg, additives for food, cosmetics, cement, paint, ink, etc.). Furthermore, it can be mixed with a resin or an emulsion and used as a reinforcing material.

  The features of the present invention will be more specifically described below with reference to experimental examples. The materials, amounts used, proportions, treatment contents, treatment procedures, etc. shown in the following experimental examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below.

(Experimental example 1)
[Production of phosphorylated pulp]
As softwood kraft pulp, pulp manufactured by Oji Paper Co., Ltd. (solids content 93% by mass, sheet form with a solid weight of 208 g / m ² , Canadian Standard Freeness (CSF) 700 ml, disintegrated and measured according to JIS P 8121) It was used. 100 parts by mass of the softwood kraft pulp (absolute dry mass) is impregnated with a mixed aqueous solution of ammonium dihydrogen phosphate and urea, and squeezed so that 49 parts by mass of ammonium dihydrogen phosphate and 130 parts by mass of urea are obtained. I got a pulp. The obtained drug-impregnated pulp was dried by a dryer at 105 ° C., and the water was evaporated to pre-dry. Then, it heated for 10 minutes with the ventilation dryer set to 140 degreeC. Thus, phosphate groups were introduced to cellulose in the pulp to obtain a phosphorylated pulp.

[Washing of phosphorylated pulp]
10000 parts by mass of ion-exchanged water is poured with respect to 100 parts by mass of the obtained phosphorylated pulp (absolute dry mass), stirred and dispersed uniformly, and then filtered and dewatered to obtain a dewatered sheet twice Repeatedly, dewatered sheet A of phosphorylated pulp was obtained.

[Multiple phosphorylation]
In the same manner as above, the step of introducing a phosphate group and the step of filtering and dewatering the resulting dehydrated sheet A of the phosphorylated pulp were further repeated twice (total number of times of phosphorylation and filtration and dewatering was 3 times ). Thus, a dewatered sheet B of phosphorylated pulp was obtained.

[Machine processing]
Ion-exchanged water was added to the dehydrated sheet B of the obtained phosphorylated pulp to obtain a pulp suspension having a solid content concentration of 1.0% by mass. This pulp suspension was passed 5 times at a pressure of 245 MPa with a wet atomization device (manufactured by Sugino Machine Co., Ltd .: Ultimizer) to obtain a fine fibrous cellulose dispersion.

[Solvent substitution of fine fibrous cellulose dispersion]
The obtained fine fibrous cellulose dispersion was suction filtered on a membrane filter with a pore diameter of 0.45 μm (Adobetech Co., Ltd., a hydrophilic PTFE membrane filter) to obtain a fine fibrous cellulose wet sheet A. Isopropyl alcohol was added to the fine fibrous cellulose wet sheet A so that the solid content concentration was 1.0% by mass, and suction filtration was performed again using the above membrane filter. Thereafter, addition of isopropyl alcohol and suction filtration were repeated twice to obtain a fine fibrous cellulose wet sheet B (solid content concentration 10.0%).

[Introduction of organic group to fine fibrous cellulose]
96.0 g of the fine fibrous cellulose wet sheet B is taken and placed in a flask, and 3.8 g of a 25% by mass aqueous sodium hydroxide solution is added and permeated, 150 g of isopropyl alcohol, methyl glycidyl ether (Tokyo Kasei Kogyo Co., Ltd. 9.8 g) was added and reacted at 80 ° C. for 5 hours while stirring under nitrogen. After cooling, it was neutralized with acetic acid and washed with isopropyl alcohol and water. According to the above procedure, a fine fibrous cellulose-containing substance in which a 2-hydroxy-3-methoxypropyl group is introduced to the phosphoric acid group of fine fibrous cellulose is obtained.

[Sheeting of fine fibrous cellulose content]
The obtained fine fibrous cellulose-containing material was spread flat on a membrane filter with a pore diameter of 0.45 μm (Adobetech Co., Ltd., a hydrophilic PTFE membrane filter), and suction filtration was performed. Subsequently, it was made to pass twice in a rotary drier (manufactured by JAPO, L-30) set to a temperature of 100 ° C. (processing time per one treatment was 7 minutes) to obtain a fine fibrous cellulose-containing sheet. The solid content of the obtained fine fibrous cellulose-containing sheet was 50% by mass.

[Mixing of fine fibrous cellulose-containing sheet and resin]
The obtained fine fibrous cellulose-containing sheet was pulverized using a cutter mill (manufactured by Iwatani, IFM-720G) and then passed through a 5 mm screen to obtain a pulverized product for molding. 31.0 parts by mass of a ground product for molding, 68.5 parts by mass of pellets of homopolypropylene (Novatec MA3, manufactured by Nippon Polypropylene Corporation) as a matrix resin, and an antioxidant (Irganox B 225, manufactured by BASF Corp.) 0.5 By dry blending with parts by mass, a resin mixture containing fine fibrous cellulose was obtained.

  Then, the resin mixture was charged into a small twin-screw kneader ("MC15" manufactured by DSM Xplore), and melt-kneaded for 5 minutes. The barrel temperature at that time was 200 ° C., and the screw rotation speed was 50 rpm. After 5 minutes, the molten resin was extruded in a rod shape from the resin discharge port, placed on a stainless steel tray, cooled at room temperature to solidify, and then cut into pellets to obtain a fine fibrous cellulose-containing resin composition .

[Evaluation]
By injection-molding the pellet-like fine fibrous cellulose-containing resin composition obtained in Experimental Example 1, a fine fibrous cellulose-containing resin molded product was obtained. The flexural modulus of this molded body was measured by the following method. As a result, the fine fibrous cellulose-containing resin molded product molded from the fine fibrous cellulose-containing resin composition obtained in Experimental Example 1 was excellent in flexural modulus.
Further, the dispersibility of the fine fibrous cellulose in the fine fibrous cellulose-containing resin molded product was evaluated. The dispersibility of the fine fibrous cellulose in the fine fibrous cellulose-containing resin molded product obtained by molding the fine fibrous cellulose-containing resin composition obtained in Experimental Example 1 was excellent.

[Measurement of flexural modulus]
The fine fibrous cellulose-containing resin molded product obtained in Experimental Example 1 was injection-molded by an injection molding machine (PNX-III, manufactured by Nissei Resin Co., Ltd.) to prepare a test piece. As a test piece, a multipurpose test piece (JIS K 7139: A type) for a bending test was produced. The flexural modulus was measured according to JIS K 7171 using the above test piece. As a bending tester, a tensile / compression tester (Tensilon RTF-2430 manufactured by Yamato Scientific Co., Ltd.) was used, and the bending speed was 5 mm / min.

[Dispersibility of fine fibrous cellulose]
The multipurpose test pieces prepared for the bending test were visually observed, and the dispersibility of the fine fibrous cellulose in the matrix resin was evaluated according to the following criteria.
Good: No aggregates of fine fibrous cellulose were found in the multipurpose test piece. Δ: Some fine fibrous cellulose aggregates were found in the multipurpose test piece, but this level is not a problem in practical use.
X: Many aggregates of fine fibrous cellulose were confirmed in the multipurpose test piece, which is a level at which it can not be used.

(Experimental example 2 to 102)
The surface modifying agent and surface modification reaction conditions in the organic group introduction step to the fine fibrous cellulose can be as shown in Tables 1 to 4 below, and the fine fibrous cellulose-containing substances of Experimental Examples 2 to 102 can be obtained.

(Experimental example 103)
The fine fibrous cellulose dispersion used in Experimental Example 1 was spread flat on a membrane filter with a pore diameter of 0.45 μm (a membrane filter made of hydrophilic PTFE manufactured by Advantec Co., Ltd.), and suction filtration was performed. Subsequently, it was made to pass twice in a rotary drier (manufactured by JAPO, L-30) set to a temperature of 100 ° C. (processing time per one time was 7 minutes), to obtain a fine fibrous cellulose-containing sheet C. The solid content of the obtained fine fibrous cellulose-containing sheet C was 50% by mass.
A fine fibrous cellulose-containing resin composition was obtained in the same manner as in Experimental Example 1 except that the fine fibrous cellulose-containing sheet C was used as the fine fibrous cellulose-containing sheet.

(Experimental example 104)
Dry blending of 100 parts by mass of pellets of homopolypropylene (Novatec MA3, manufactured by Nippon Polypropylene Corp.) and 0.5 parts by mass of an antioxidant (manufactured by BASF, Irganox B 225) without using a fine fibrous cellulose-containing sheet Then, an organic resin composition cut into pellets was obtained in the same manner as in Experimental Example 1 except that a resin mixture was obtained.

  It can be confirmed that the groups of (a) and (b) are contained in any of the experimental examples except for the experimental examples 103 and 104. The fine fibrous cellulose-containing resin molded product obtained in Experimental Examples 1 to 102 has a tendency to be excellent in flexural modulus. Also in the fine fibrous cellulose-containing resin molded product obtained in Experimental Examples 1 to 102, the dispersibility of the fine fibrous cellulose tends to be good.

Claims (4)

What is claimed is: 1. A fine fibrous cellulose-containing material comprising fine fibrous cellulose, wherein
The said fine fibrous cellulose is a phosphoric acid which does not have (a) a group which a phosphoric acid group and an organic group having one or more carbon atoms covalently bond, and (b) an organic group having one or more carbon atoms. possess and based on, the,
The fine fibrous cellulose-containing material wherein the group formed by covalent bonding of the (a) phosphoric acid group and the organic group having one or more carbon atoms is a group represented by the following formula (1) ;

In formula (1), n represents an integer of 1 to ⁿ ; R and R ⁿ each independently represent a hydrogen atom or an organic group having one or more carbon atoms, and at least one of R and R ⁿ is carbon X and X ⁿ each represents a linking group or a single bond. Wherein X and X ⁿ is an ester bond, microfibrous cellulose-containing material according to claim 1 is a linking group containing at least one selected from silyl ester bond and an amide bond.   The fine fibrous cellulose-containing material according to claim 1 or 2, wherein the carbon number of the organic group is 10 or less. A fine fibrous cellulose-containing resin composition comprising the fine fibrous cellulose-containing material according to any one of claims 1 to 3 and a resin.

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