JP6525758B2 - Photocurable composition for three-dimensional shaping - Google Patents

Description

  The present invention relates to a photocurable composition for three-dimensional shaping. More specifically, a photocurable composition suitable as a material for precision molding, electric / electronic products, products such as automobiles, or parts or casings thereof, and a method for producing an optically shaped article using the composition And an optically shaped article obtained by the production method.

  In recent years, since a three-dimensional object can be manufactured with good dimensional accuracy without using a mold, various methods for three-dimensionally optical formation have been studied.

  For example, in Patent Document 1, a resin composition for optical three-dimensional shape formation comprising a cationically polymerizable organic compound, a radically polymerizable organic compound, an active energy ray sensitive cationic polymerization initiator, and an active energy ray sensitive radical polymerization initiator When a specific aromatic triepoxy compound is contained in a predetermined ratio as a cationically polymerizable organic compound, the three-dimensional object obtained from the resin composition for optical three-dimensional modeling has a high heat distortion temperature and is heat resistant. Excellent mechanical strength such as tensile strength and bending strength, and a suitable degree of elongation to be excellent in toughness, and further excellent in transparency, small in color change such as yellowing, excellent in hue and excellent in transparency It is reported that the color and hue are maintained even after being exposed to high temperatures.

  Further, in Patent Document 2, a monofunctional monomer having a low glass transition temperature of its cured product has a rate of increase in viscosity during the curing reaction slower than a monofunctional monomer having a high glass transition temperature of its homopolymer. By curing the ink composition containing a specific amount of a monofunctional monomer having a low glass transition temperature of the polymer, it is possible to secure a time for relaxing the curing shrinkage of the ink composition, and to achieve both rubber elasticity and dimensional stability. It is disclosed that a cured product is obtained.

JP, 2010-265408, A JP, 2015-78255, A

  However, the application application of the technique for three-dimensionally optical shaping is expanded, and further improvement is required. That is, since the surrounding conditions at the time of shaping are diverse, while the composition before curing having the handling property (viscosity) corresponding to each situation is required, the composition is cured while Development of the photocurable composition for three-dimensional shaping | molding that the intensity | strength becomes stronger in any obtained and the intensity | strength is maintained also in a high temperature range is desired.

  The present invention provides a photocurable composition for three-dimensional shaping, which is capable of providing a three-dimensional shaped article whose viscosity can be easily adjusted and which is excellent in mechanical strength even at high temperatures, and optical shaping using the composition The present invention relates to a method for producing an object, and a photofabricated product obtained by the method.

The present invention relates to the following [1] to [3].
[1] A) A photocurable resin precursor, and B) A fine cellulose fiber having a number average fiber diameter of 0.5 nm to 200 nm and a carboxy group content of 0.1 mmol / g or more and / or a modification thereof A photocurable composition for three-dimensional shaping, comprising a texture.
[2] A method for producing an optically shaped article, comprising using the photocurable composition according to the above [1] for an optical shaping apparatus.
[3] A photofabricated object obtained by the method according to [2].

  The photocurable composition of the present invention exhibits an excellent effect that the three-dimensional object obtained by curing the composition has excellent mechanical strength even at high temperatures while the viscosity can be easily adjusted.

  The photocurable composition of the present invention is A) a photocurable resin precursor, and B) fine particles having a number average fiber diameter of 0.5 nm to 200 nm and a carboxy group content of 0.1 mmol / g or more. It is characterized in that it contains cellulose fiber and / or its modified product. In the present specification, such a composition may be described as the resin composition of the present invention.

  Generally, when the curable resin composition changes the composition of the resin precursor, not only the composition before curing but also the physical properties of the shaped article itself after curing tends to fluctuate, so each of the composition before curing and the shaped article It is not easy to adjust the type and amount of the resin precursor in order to impart desired physical properties. On the other hand, conventionally, in order to adjust the viscosity and dispersion stability of the composition, a polymer material is used. However, the curable resin composition in which the conventional polymer material was blended had insufficient mechanical strength at high temperature of the shaped article after curing. Therefore, in the present invention, by adding a specific fine cellulose fiber and / or a modified product thereof to a system containing a photocurable resin precursor, it is easy to adjust the viscosity of the composition before curing while curing It has been found that the later shaped object can improve the mechanical strength under high temperature. Although the detailed reason is unknown, the dispersion in the resin is improved by the dispersion of the cellulose fiber having a fiber diameter smaller than that of the conventional nanofiber, so that the viscosity can be easily adjusted. Moreover, since the said fine cellulose fiber is comparatively strong to heat, it is estimated that it becomes possible to improve the intensity | strength in a high temperature area | region, in order that fiber may express intertwining strength. In addition, in this specification, "mechanical strength" means the thing of the characteristic evaluated by the below-mentioned "storage elastic modulus."

[Photo-curable composition]
[Photo-curable resin precursor]
The photocurable resin precursor in the present invention is not particularly limited as long as the polymerization reaction proceeds by using a photopolymerization initiator if necessary by irradiation with active energy rays such as ultraviolet rays and electron beams. For example, a monomer (monofunctional monomer, polyfunctional monomer), an oligomer having a reactive unsaturated group, a resin, or the like can be used.

  Examples of monofunctional monomers include (meth) acrylic monomers such as (meth) acrylic acid ester, vinyl monomers such as vinylpyrrolidone, isobornyl (meth) acrylate, adamantyl (meth) acrylate and the like. And (meth) acrylates having a bridged cyclic hydrocarbon group and the like. The polyfunctional monomers include polyfunctional monomers having a polymerizable group of about 2 to 8, and examples of the bifunctional monomers include ethylene glycol di (meth) acrylate, propylene glycol di (meth) And di) (meth) acrylates having a bridged cyclic hydrocarbon group such as acrylate). As a 3-8 functional monomer, glycerin tri (meth) acrylate etc. are mentioned, for example. In the present invention, (meth) acrylate includes methacrylic acid compounds and acrylic acid compounds.

  As an oligomer or resin having a reactive unsaturated group, (meth) acrylate of bisphenol A-alkylene oxide adduct, epoxy (meth) acrylate (bisphenol A epoxy (meth) acrylate, novolac epoxy (meth) acrylate, etc.) , Polyester (meth) acrylate (eg, aliphatic polyester type (meth) acrylate, aromatic polyester type (meth) acrylate, etc.), urethane (meth) acrylate (polyester type urethane (meth) acrylate, polyether type urethane (meth) Acrylate and the like), silicone (meth) acrylate and the like can be exemplified. Among them, one or more selected from the group consisting of an acrylic resin, a (meth) acrylic resin, and an epoxy resin is preferable. These oligomers or resins may be used together with the monomers.

  These can be used alone or in combination of two or more, and when combined, the composition can be appropriately adjusted.

  Moreover, these may use what was prepared according to the well-known method, and may use a commercial item. In the present invention, for example, OBJET FULL CURE 720 (manufactured by Stratasys, acrylic resin), SCR 774, SCR 11120, SCR 780, and SCR 780 C (all of which are manufactured by DIMEC, epoxy resin) may be used as suitable commercial products. it can.

[Fine cellulose fiber or its modified product]
Examples of the fine cellulose fiber or its modified product used in the present invention include known fine cellulose fibers and fine cellulose fiber modified products in which a modifying group is introduced into the fine cellulose fiber. In the present specification, that a modifying group is introduced into the fine cellulose fiber means that the modifying group is bound to the carboxy group on the surface of the fine cellulose fiber by an ionic bond and / or an amide bond. . More specifically, a state in which an amine having a modifying group is ionically bonded to the deprotonated carboxy group of the fine cellulose fiber, or a carbon atom of an amide group is covalently bonded to the cellulose skeleton of the fine cellulose fiber Directly or via a linking group.

<Fine cellulose fiber>
(Number average fiber diameter)
The fine cellulose fiber in the present invention has a number average fiber diameter of 0.5 nm or more and 200 nm or less, preferably from 0.8 nm or more, more preferably from the viewpoint of dispersing the fine cellulose fiber having a uniform fiber diameter in a shaped article. Preferably, it is 1.0 nm or more. Further, from the viewpoint of handleability and strength development of a shaped product, it is preferably 100 nm or less, more preferably 50 nm or less, still more preferably 20 nm or less, still more preferably 10 nm or less, still more preferably 5 nm or less. In addition, in this specification, the number average fiber diameter of a cellulose fiber can be measured using an atomic force microscope (AFM), and is specifically measured by the method as described in the below-mentioned Example. In general, the smallest unit of cellulose nanofibers prepared from higher plants is packed with 6 × 6 molecular chains in a substantially square shape, so consider the height analyzed in the image by AFM as the width of the fiber Can.

(Carboxyl group content)
The fine cellulose fiber in the present invention has a carboxy group content of 0.1 mmol / g or more, but is preferably 0.4 mmol / g or more, more preferably from the viewpoint of dispersibility in the resin composition and introduction of a modifying group. It is 0.6 mmol / g or more, more preferably 0.8 mmol / g or more. Also, from the viewpoint of handleability and cost, it is preferably 3 mmol / g or less, more preferably 2 mmol / g or less, and still more preferably 1.8 mmol / g or less. Fine cellulose fibers having a carboxy group content outside the above range may be unintentionally contained as impurities in the fine cellulose fibers used in the present invention. In addition, "carboxy group content" means the total amount of the carboxy group in the cellulose which comprises a fine cellulose fiber, and, specifically, it measures by the method as described in the below-mentioned Example.

(Average aspect ratio)
Further, the fine cellulose fiber in the present invention has an average aspect ratio (fiber length / fiber diameter) of preferably 10 or more, more preferably 20 or more, and still more preferably 30 or more from the viewpoint of strength development of a shaped article. Also, from the viewpoint of handleability, it is preferably 1000 or less, more preferably 800 or less, still more preferably 600 or less, and still more preferably 400 or less. The fine cellulose fiber having an average aspect ratio in the above range is excellent in the dispersibility in the composition when blended into a resin precursor, has a high mechanical strength, and can obtain a composition which is less likely to cause brittle fracture. In the present specification, in the present specification, the average aspect ratio is the aspect ratio of cellulose fibers according to the following formula (1) from the relationship between the concentration of cellulose fibers in the dispersion and the specific viscosity of the dispersion to water. Calculate back In addition, following formula (1) is the The Theory of Polymer Dynamics, M. DOI and D. F. The relationship between the viscosity equation (8.138) of a rigid rod molecule described in EDWARDS, CLARENDON PRESS OXFORD, 1986, P. 312 and Lb ² × ρ = M / N _A , wherein L is the fiber length and b is the fiber width (The cellulose fiber cross section is square), ρ is the concentration of cellulose fiber (kg / m ³ ), M is the molecular weight, and N _A is the Avogadro number. In the above viscosity formula (8.138), the rigid rod-like molecule is cellulose fiber. In the following formula (1), η _SP is a specific viscosity, π is a circle ratio, ln is a natural logarithm, P is an aspect ratio (L / b), γ = 0.8, and _{S S} is a density of the dispersion medium (kg / m ³ ), ρ ₀ is the density of cellulose crystals (kg / m ³ ), and C is the mass concentration of cellulose (C = ρ / ρ _S ).

(Degree of crystallinity)
The degree of crystallization of the fine cellulose fiber is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, still more preferably 45% or more, from the viewpoint of strength development of the shaped article. Further, from the viewpoint of cost, it is preferably 95% or less, more preferably 90% or less, further preferably 85% or less, and still more preferably 80% or less. In addition, in this specification, the crystallinity degree of a cellulose is a cellulose I-type crystallinity degree calculated by the Segal method from the diffraction intensity value by X-ray diffraction method, and is defined by the following formula (A).
Cellulose type I crystallinity (%) = [(I22.6−I18.5) /I22.6] × 100 (A)
[Wherein, I22.6 is the diffraction intensity of the grating surface (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, I18.5 is the amorphous part (diffraction angle 2θ = 18.5 °) Indicates the diffraction intensity of
In addition, cellulose I type is a crystal form of natural cellulose, and cellulose I type crystallinity means the ratio for which the amount of the crystal region occupies in the whole cellulose.

<Modified product of fine cellulose fiber (fine cellulose fiber composite)>
Although the modified product of the fine cellulose fiber used in the present invention shows that the above-mentioned fine cellulose fiber surface has a modifying group bonded thereto, for example, it selects the carboxy group already existing on the fine cellulose fiber surface Thus, it can be obtained by ionically bonding and / or amide bonding an amine having a modifying group. In the present specification, the modified product of fine cellulose fibers may be described as a fine cellulose fiber composite.

(Amine having a modifying group)
As the amine having a modifying group, any one having a modifying group described later may be used, and in the case of ionic bonding, any of a primary amine, a secondary amine, a tertiary amine and a quaternary ammonium cation may be used. However, from the viewpoint of reactivity, primary amines or secondary amines or quaternary ammonium cations are preferred, primary amines or quaternary ammonium cations are more preferred, and primary amines are even more preferred. In the case of an amide bond, any of primary amines and secondary amines may be used, but from the viewpoint of reactivity, primary amines are preferable.

  From the viewpoint of improving the strength of a shaped article, a hydrocarbon group, an ethylene oxide / propylene oxide (EO / PO) copolymer, or the like can be used as the modifying group in the present invention. These may be introduced into the fine cellulose fiber singly or in combination of two or more.

  The hydrocarbon group includes, for example, a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, a cyclic saturated hydrocarbon group, and an aromatic hydrocarbon group, and from the viewpoint of suppressing side reactions and stability From the viewpoint, a chain saturated hydrocarbon group, a cyclic saturated hydrocarbon group, and an aromatic hydrocarbon group are preferable.

  The chain saturated hydrocarbon group may be linear or branched. The carbon number of the chain saturated hydrocarbon group is preferably 1 or more, more preferably 2 or more, and still more preferably 3 or more, from the viewpoint of improving the strength of the shaped article. Moreover, from the same viewpoint, 30 or less is preferable and 18 or less is more preferable.

  Specific examples of the chain saturated hydrocarbon group include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, isobutyl group, pentyl group, tert-pentyl group, Examples include isopentyl group, hexyl group, isohexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, octadecyl group, docosyl group, octacosanyl group, etc. From the viewpoint of improving the strength of the polymer, preferably propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, pentyl, tert-pentyl, isopentyl, hexyl, isohexyl, heptyl Group, octyl group, 2-ethylhexyl group, nonyl group, decyl Group, dodecyl group, tridecyl group, tetradecyl group, octadecyl group, docosyl group, octacosanyl group, more preferably propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, isobutyl group, pentyl group, tert-pentyl, isopentyl, hexyl, isohexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl and octadecyl. These may be introduced singly or in combination of two or more in any proportion.

  The chain unsaturated hydrocarbon group may be linear or branched. The carbon number of the chain unsaturated hydrocarbon group is preferably 1 or more, more preferably 2 or more, and still more preferably 3 or more from the viewpoint of handleability. Moreover, from a viewpoint of availability, 30 or less is preferable and 18 or less is more preferable.

  Specific examples of the chain unsaturated hydrocarbon group include, for example, ethylene group, propylene group, butene group, isobutene group, isoprene group, pentene group, hexene group, heptene group, octene group, octene group, nonene group, decene group, dodecene group And tridecene group, tetradecene group and octadecene group, and from the viewpoint of affinity with the precursor, preferably ethylene group, propylene group, butene group, isobutene group, isoprene group, penten group, hexene group, heptene group, octene group And a nonene group, a decene group and a dodecene group, more preferably a hexene group, a heptene group, an octene group, a nonene group, a decene group and a dodecene group. These may be introduced singly or in combination of two or more in any proportion.

  The carbon number of the cyclic saturated hydrocarbon group is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more from the viewpoint of handleability. Also, from the viewpoint of easy availability, 20 or less is preferable, and 16 or less is more preferable.

  Specific examples of the cyclic saturated hydrocarbon group include, for example, cyclopropane group, cyclobutyl group, cyclopentane group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group, cyclotridecyl group And cyclotetradecyl group, cyclooctadecyl group and the like, and from the viewpoint of affinity with the precursor, preferably cyclopropane group, cyclobutyl group, cyclopentane group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group And a cyclodecyl group and a cyclododecyl group, more preferably a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group and a cyclododecyl group. These may be introduced singly or in combination of two or more in any proportion.

  The aromatic hydrocarbon group is selected, for example, from the group consisting of an aryl group and an aralkyl group. The aryl group and the aralkyl group may be those in which the aromatic ring itself is substituted or unsubstituted.

  The total carbon number of the aryl group may be 6 or more, preferably 24 or less, more preferably 20 or less, still more preferably 14 or less, still more preferably 12 or less, from the viewpoint of the affinity with the precursor Is 10 or less.

  The total carbon number of the aralkyl group is 7 or more, preferably 8 or more from the viewpoint of affinity with the precursor, and preferably 24 or less, more preferably 20 or less, more preferably from the same viewpoint. Is 14 or less, more preferably 13 or less, and still more preferably 11 or less.

  Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a biphenyl group, a triphenyl group, a terphenyl group, and a group in which these groups are substituted with a substituent described later. One species alone or two or more species may be introduced at any ratio. Among them, from the viewpoint of the affinity to the precursor, a phenyl group, a biphenyl group and a terphenyl group are preferable, and a phenyl group is more preferable.

  As the aralkyl group, for example, a benzyl group, a phenethyl group, a phenylpropyl group, a phenylpentyl group, a phenylhexyl group, a phenylheptyl group, a phenyloctyl group, and an aromatic group of these groups are substituted by a substituent described later And the like, and these may be introduced singly or in combination of two or more at an arbitrary ratio. Among them, from the viewpoint of affinity with the precursor, benzyl group, phenethyl group, phenylpropyl group, phenylpentyl group, phenylhexyl group, phenylheptyl group is preferable, and benzyl group, phenethyl group, phenylpropyl group, phenylpentyl group A phenylhexyl group is more preferable, and a benzyl group, a phenethyl group, a phenylpropyl group and a phenylpentyl group are more preferable.

  The amine having a hydrocarbon group can be prepared according to known methods. Commercially available products may be used, and as the amine having a chain saturated hydrocarbon group, for example, propylamine, isopropylamine, butylamine, sec-butylamine, tert-butylamine, isobutylamine, pentylamine, tert-pentylamine , Isopentylamine, hexylamine, isohexylamine, heptylamine, octylamine, 2-ethylhexylamine, nonylamine, nonylamine, decylamine, dodecylamine, tridecylamine, tetradecylamine, octadecylamine, docosylamine, octacosanylamine Can. As the amine having a chain unsaturated hydrocarbon group, ethyleneamine, propyleneamine, buteneamine, isobuteneamine, isopreneamine, penteneamine, hexenamine, heptenamine, octeneamine, noneneamine, decenamine, dodecenamine can be used. As the amine having a cyclic saturated hydrocarbon group, cyclopropanamine, cyclobutylamine, cyclopentaneamine, cyclohexylamine, cycloheptylamine, cyclooctylamine, cyclononylamine, cyclodecylamine and cyclododecylamine can be used. . Examples of the amine having an aromatic hydrocarbon group include aniline, 4-biphenylylamine, diphenylamine, 2-aminonaphthalene, p-terphenylamine, 2-aminoanthracene, 2-aminoanthraquinone, benzylamine, phenethylamine, -Phenylpropylamine, 5-phenylpentylamine, 6-phenylhexylamine, 7-phenylheptylamine, 8-phenyloctylamine can be used. Also, as the quaternary alkyl ammonium cation, for example, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetraethyl ammonium chloride, tetrabutyl ammonium hydroxide, tetrapropyl ammonium hydroxide, tetrabutyl ammonium chloride, lauryl trimethyl ammonium chloride, Dilauryldimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, cetyl trimethyl ammonium chloride, alkyl benzyl dimethyl ammonium chloride can be used.

  The average bonding amount (mmol / g) of hydrocarbon groups in the fine cellulose fiber composite is the chained saturated hydrocarbon group, the chain unsaturated hydrocarbon group, and the cyclic saturated hydrocarbon group, for the fine cellulose fiber. On the other hand, it is preferably 0.001 mmol / g or more, more preferably 0.005 mmol / g or more, and still more preferably 0.01 mmol / g or more because control of the bonding amount of the hydrocarbon group is easy. Also, from the viewpoint of reactivity, it is preferably 3 mmol / g or less, more preferably 2 mmol / g or less. With regard to the aromatic hydrocarbon group, the average bonding amount of the hydrocarbon group is preferably 0.1 mmol / g or more, more preferably 0.2 mmol / g or more, still more preferably 0 from the viewpoint of the strength of the shaped product. .5 mmol / g or more. Also, from the viewpoint of reactivity, it is preferably 3 mmol / g or less, more preferably 2 mmol / g or less, and still more preferably 1.5 mmol / g or less. Here, even when a hydrocarbon group selected from a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, and a cyclic saturated hydrocarbon group and an aromatic hydrocarbon group are simultaneously introduced. The average binding amount of each is preferably within the above range.

  In addition, the average bonding amount (parts by mass) of hydrocarbon groups in the fine cellulose fiber composite is the above-mentioned fine cellulose fiber for the chain saturated hydrocarbon group, the chain unsaturated hydrocarbon group, and the cyclic saturated hydrocarbon group. The amount is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and still more preferably 20 parts by mass or more based on 100 parts by mass because control of the bonding amount of hydrocarbon groups is easy. Also, from the viewpoint of reactivity, it is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and still more preferably 40 parts by mass or less. In addition, with respect to the aromatic hydrocarbon group, the average bonding amount of the hydrocarbon group is preferably 5 parts by mass or more, more preferably 10 parts by mass or more from the viewpoint of the strength of the shaped article. Also, from the viewpoint of reactivity, it is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and still more preferably 30 parts by mass or less. Here, even when a hydrocarbon group selected from a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, and a cyclic saturated hydrocarbon group and an aromatic hydrocarbon group are simultaneously introduced. The average binding amount of each is preferably within the above range.

  Similarly, the average bonding amount (mass%) of the hydrocarbon group in the fine cellulose fiber composite is a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, and a cyclic saturated hydrocarbon group. The amount is preferably 10% by mass or more, more preferably 15% by mass or more, and still more preferably 20% by mass or more because control of the amount of bonding of groups is easy. Also, from the viewpoint of reactivity, it is preferably 50% by mass or less, more preferably 45% by mass or less, and still more preferably 40% by mass or less. In addition, with respect to the aromatic hydrocarbon group, the average bonding amount of the hydrocarbon group is preferably 5% by mass or more, more preferably 10% by mass or more from the viewpoint of the strength of the shaped article. In addition, from the viewpoint of reactivity, the content is preferably 40% by mass or less, more preferably 35% by mass or less, and still more preferably 30% by mass or less. Here, even when a hydrocarbon group selected from a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, and a cyclic saturated hydrocarbon group and an aromatic hydrocarbon group are simultaneously introduced. The average binding amount of each is preferably within the above range.

  In addition, with respect to the chain saturated hydrocarbon group, the chain unsaturated hydrocarbon group, and the cyclic saturated hydrocarbon group, the introduction rate of the hydrocarbon group is preferably 10% or more from the viewpoint of the strength of the obtained molded product. More preferably, it is 30% or more, more preferably 50% or more, further preferably 60% or more, further preferably 70% or more, and from the viewpoint of reactivity, preferably 99% or less, more preferably 97% or less. More preferably, it is 95% or less, more preferably 90% or less. Further, with regard to the aromatic hydrocarbon group, the introduction rate of the hydrocarbon group is preferably 10% or more, more preferably 30% or more, and still more preferably 50% or more, from the viewpoint of obtaining a shaped article excellent in mechanical strength. It is more preferably 60% or more, still more preferably 70% or more, still more preferably 80% or more, and from the viewpoint of reactivity, preferably 99% or less, more preferably 97% or less, still more preferably 95% or less Preferably it is 90% or less. Here, when a hydrocarbon group selected from a chain saturated hydrocarbon group, a chain unsaturated hydrocarbon group, and a cyclic saturated hydrocarbon group and an aromatic hydrocarbon group are simultaneously introduced, introduction is carried out. It is preferable that the sum of the ratios falls within the above range as long as it does not exceed 100% of the upper limit.

  The EO / PO copolymerized part means a structure in which ethylene oxide (EO) and propylene oxide (PO) are randomly or block-polymerized. For example, when an amine having an EO / PO copolymer part is represented by the formula (i) described later, ethylene oxide (EO) and propylene oxide (PO) form a chain structure of random or block, but the amine (EO) a (PO) b, (EO) c (PO) d, and (EO) e (PO) f are chained when the amine having the structure represented by the formula (ii) described later is It does not have to be

  The content (mol%) of PO in the EO / PO copolymer part is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more, from the viewpoint of the strength of the shaped product. The amount is preferably 10 mol% or more, and from the same viewpoint, preferably 100 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less, still more preferably 75 mol% or less, still more preferably 60 mol % Or less, more preferably 50 mol% or less, still more preferably 40 mol% or less, still more preferably 30 mol% or less. The PO content of 100 mol% means that the EO / PO copolymerized part is composed only of PO, and in the present invention, the PO polymerized part may be introduced.

  The molecular weight of the EO / PO copolymer part is preferably 700 or more, more preferably 1,000 or more, still more preferably 1,500 or more from the viewpoint of the dispersibility in the precursor and the strength of the shaped article, the shaped article From the viewpoint of strength, preferably 10,000 or less, more preferably 7,000 or less, still more preferably 5,000 or less, still more preferably 4,000 or less, still more preferably 3,500 or less, more preferably 2, It is 500 or less. For example, when it is an amine having a structure represented by the formula (ii) described later, the total molecular weight of (EO) a (PO) b + (EO) c (PO) d + (EO) e (PO) f is And the molecular weight of the EO / PO copolymer part. The content (mol%) of PO in the EO / PO copolymer part and the molecular weight of the EO / PO copolymer part can be calculated from the average added mole number at the time of producing the amine.

  The EO / PO copolymer and the amine are preferably bonded directly or via a linking group. The linking group is preferably a hydrocarbon group, and an alkylene group having a carbon number of preferably 1 to 6, more preferably 1 to 3 is used. For example, ethylene and propylene are preferred.

  Examples of the amine having such an EO / PO copolymerized part include the following formula (i):

[Wherein, R ₁ represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a —CH ₂ CH (CH ₃ ) NH ₂ group, or a group represented by the following formula (ii) , EO and PO exist in random or block, a is a positive number indicating the average addition mole number of EO, b is a positive number indicating the average addition mole number of PO]
The compound represented by these is mentioned.

Formula (ii):

[Wherein, n is 0 or 1, R ₂ is a phenyl group, a hydrogen atom, or a linear or branched alkyl group having 1 to 3 carbon atoms, and EO and PO are present in random or block] , C and e indicate the average addition mole number of EO, are independently a number of 0 to 50, d and f indicate the average addition mole number of PO, and are independently a number of 1 to 50.

  A in the formula (i) represents the average added mole number of EO, and preferably 11 or more, more preferably 15 or more, still more preferably 20 or more, still more preferably 25 or more, still more preferably from the viewpoint of the strength of the shaped article It is 30 or more, and from the same viewpoint, preferably 100 or less, more preferably 70 or less, still more preferably 60 or less, further preferably 50 or less, further preferably 40 or less.

  B in formula (i) represents the average addition mole number of PO, and is preferably 1 or more, more preferably 2 or more, still more preferably 3 or more from the viewpoint of the strength of the shaped article, and from the same viewpoint, preferably It is 50 or less, more preferably 40 or less, further preferably 30 or less, further preferably 25 or less, further preferably 20 or less, further preferably 15 or less.

  In addition, when the amine is represented by the above formula (i), the content (mol%) of PO in the EO / PO copolymer part is calculated from the a and b in the content of PO in the copolymer part. If the amine is represented by the formula (i) and the formula (ii), the formula: (b + d + f) × can be obtained from the formula: b × 100 / (a + b) It can be determined from 100 / (a + b + c + d + e + f). The preferred range is as described above.

R ₁ in the formula (i) is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a —CH ₂ CH (CH ₃ ) NH ₂ group, or a group represented by the above formula (ii) Although shown, a hydrogen atom is preferred from the viewpoint of the strength of the shaped article. The linear or branched alkyl group having 1 to 6 carbon atoms is preferably a methyl group, an ethyl group, or an iso or normal propyl group.

When R ₁ in the formula (i) is a group represented by the formula (ii), the linear or branched alkyl group having 1 to 3 carbon atoms of R ₂ in the formula (ii) is preferably It is a methyl group or an ethyl group. When R ₂ is a methyl group or an ethyl group, n is preferably 1, and when R ₂ is a hydrogen atom, n is preferably 0. Moreover, as c and e in Formula (ii), 10-30 are preferable independently, 5-25 are preferable as d and f independently.

  The amine having an EO / PO copolymerized part represented by the formula (i) can be prepared according to a known method. For example, after adding ethylene oxide and propylene oxide in a desired amount to propylene glycol alkyl ether, the hydroxyl group terminal may be aminated. If necessary, the terminal can be made a hydrogen atom by cleaving the alkyl ether with an acid. JP-A-3-181448 can be referred to for the manufacturing method of these.

  In addition, commercially available products are also suitably used, and specific examples thereof include Jeffamine M-2070, Jeffamine M-2005, Jeffamine M-1000, Surfoamine B200, Surfoamine L100, Surfoamine L200, Surfoamine L207, Surfoamine L300, Xerfoamine L300, XFJ manufactured by HUNTSMAN. -501, XTJ-506, XTJ-507, XTJ-508; M3000 manufactured by BASF, Jeffamine ED-900, Jeffamine ED-2003, Jeffamine D-2000, Jeffamine D-4000, XTJ-510, Jeffamine T-3000, Jeffamine T-5000, XTJ-502, XTJ-509, X J-510 and the like. These may be used alone or in combination of two or more.

  The average bonding amount (mmol / g) of the EO / PO copolymer part in the fine cellulose fiber composite is preferably 0.01 mmol / g or more, more preferably 0.05 mmol / g or more, from the viewpoint of the strength of the shaped article. More preferably, it is 0.1 mmol / g or more, more preferably 0.3 mmol / g or more, further preferably 0.5 mmol / g or more, still more preferably 0.8 mmol / g or more, further preferably 1 mmol / g or more. Also, from the viewpoint of reactivity, it is preferably 3 mmol / g or less, more preferably 2 mmol / g or less, and still more preferably 1.5 mmol / g or less.

  The average bonding amount (parts by mass) of the EO / PO copolymerized part in the fine cellulose fiber composite is preferably 5 parts by mass or more, more preferably from 100 parts by mass of the fine cellulose fibers from the viewpoint of the strength of the shaped article. Is 10 parts by mass or more, more preferably 20 parts by mass or more. Also, from the viewpoint of reactivity, it is preferably 500 parts by mass or less, more preferably 400 parts by mass or less, and still more preferably 300 parts by mass or less.

  The average bonding amount (% by mass) of the EO / PO copolymer part in the fine cellulose fiber composite is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 20% by mass from the viewpoint of the strength of the shaped article. % Or more. In addition, from the viewpoint of reactivity, the content is preferably 99% by mass or less, more preferably 95% by mass or less, and still more preferably 90% by mass or less.

  Further, the introduction ratio of the EO / PO copolymer part in the fine cellulose fiber composite is preferably 10% or more, more preferably 20% or more, still more preferably 30% or more, still more preferably from the viewpoint of the strength of the shaped article. It is 40% or more, more preferably 50% or more, further preferably 60% or more, further preferably 70% or more, more preferably 80% or more, and from the same viewpoint, preferably 95% or less.

  The modifying group may have a substituent, and for example, it is preferable that the total carbon number of the whole hydrocarbon group including the substituent is within the above range. As a substituent, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, an isopentyloxy group, a hexyloxy group, etc. Alkoxy group having 1 to 6 carbon atoms; methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, butoxycarbonyl group, isobutoxycarbonyl group, sec-butoxycarbonyl group, tert-butoxycarbonyl group, pentyloxycarbonyl group Group, alkoxy group such as isopentyloxycarbonyl group, alkoxy group having 1 to 6 carbon atoms; halogen atom such as fluorine atom, chlorine atom, bromine atom, iodine atom; carbon number 1 such as acetyl group, propionyl group ~ 6 Sill group; an aralkyl group; an aralkyloxy group; an alkylamino group having 1 to 6 carbon atoms; the carbon number of the alkyl group have dialkylamino group having 1 to 6. The above-mentioned hydrocarbon group itself may be bonded as a substituent.

  In the present specification, the average binding amount of the modifying group can be adjusted by the amount of amine added, the type of amine, the reaction temperature, the reaction time, the solvent and the like. Moreover, the average bonding amount (mmol / g, mass part, mass%) and introduction ratio (%) of the modifying group in the fine cellulose fiber composite are the amount by which the modifying group is introduced to the carboxy group on the fine cellulose fiber surface and It is a ratio and can be calculated by measuring the carboxy group content of the fine cellulose fiber according to a known method (for example, titration, IR measurement, etc.).

<Method for producing fine cellulose fiber composite>
The fine cellulose fiber composite can be produced according to a known method without particular limitation, as long as a modifying group can be introduced into the fine cellulose fiber. For example, a reaction for introducing a modifying group may be carried out on the previously prepared fine cellulose fiber, or a reaction for introducing a modifying group may be carried out when preparing the fine cellulose fiber. In addition, a fine cellulose fiber can be manufactured by a well-known method, for example, the method of Unexamined-Japanese-Patent No. 2011-140632.

Depending on the mode of introduction of the modifying group into the fine cellulose fiber, the following two modes can be mentioned. That is, an embodiment in which the modifying group is bound to the fine cellulose fiber by ionic bond (embodiment A), and an embodiment in which the modifying group is bound to the fine cellulose fiber by amide bond (embodiment B) can be mentioned.
Aspect A
Step (1): Step of oxidizing natural cellulose fiber in the presence of N-oxyl compound to obtain carboxy group-containing cellulose fiber Step (2A): carboxy group-containing cellulose fiber obtained in step (1) and modifying group Mixing with an amine having a [Aspect B]
Step (1): Step of oxidizing natural cellulose fiber in the presence of N-oxyl compound to obtain carboxy group-containing cellulose fiber Step (2B): carboxy group-containing cellulose fiber obtained in step (1) and modifying group The step of subjecting the amine having an amidification reaction to an amidification reaction The step (2A or 2B) may be carried out after the above-mentioned fine production process is carried out after the step (1) to obtain a carboxy group-containing fine cellulose fiber as the preferred production method. A method (first production mode) to be performed, and a method (second production mode) in which the step (2A or 2B) is performed after the step (1) and then the miniaturization step is performed.

  Hereinafter, based on the first production form of aspect A, a method for producing a fine cellulose fiber composite will be described.

[Step (1)]
Step (1) is a step of oxidizing natural cellulose fibers in the presence of an N-oxyl compound to obtain carboxy group-containing cellulose fibers.

  In step (1), first, a slurry in which natural cellulose fibers are dispersed in water is prepared. Add about 10 to 1000 times (mass basis) of water to the raw material natural cellulose fiber (absolute drying standard: mass of natural cellulose fiber after drying by heating for 30 minutes at 150 ° C.) It is obtained by processing with a mixer or the like. Examples of natural cellulose fibers include wood pulp such as softwood pulp and hardwood pulp; cotton pulp such as cotton linters and cotton lint; non-wood pulp such as straw pulp and bagasse pulp; bacterial cellulose and the like These 1 type can be used individually or in combination of 2 or more types. The natural cellulose fiber may be treated to increase the surface area such as beating. The cellulose I-type crystallinity of the commercially available pulp is usually 80% or more.

(Oxidation treatment process)
Next, the above-mentioned natural cellulose fiber is oxidized in the presence of an N-oxyl compound to obtain a carboxy group-containing cellulose fiber (hereinafter sometimes simply referred to as "oxidation treatment").

  As the N-oxyl compound, a piperidine oxyl compound having a C 1 or C 2 alkyl group, a pyrrolidine oxyl compound, an imidazoline oxyl compound, and an azaadamantane compound are preferable, and one or more heterocyclic N-oxyl compounds are preferable. . Among these, from the viewpoint of reactivity, piperidine oxyl compounds having an alkyl group having 1 or 2 carbon atoms are preferable, and 2,2,6,6-tetraalkylpiperidine-1-oxyl (TEMPO), 4-hydroxy- 2,2,6,6-tetraalkylpiperidine-1-oxyl, 4-alkoxy-2,2,6,6-tetraalkylpiperidine-1-oxyl, 4-benzoyloxy-2,2,6,6-tetra Di-tert-alkyl nitroxyl compounds such as alkyl piperidine-1-oxyl, 4-amino-2,2,6,6-tetraalkylpiperidine-1-oxyl, 4-acetamido-TEMPO, 4-carboxy-TEMPO, 4 -Phosphonoxy-TEMPO etc. are mentioned. Among these piperidine oxyl compounds, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4- Methoxy-2,2,6,6-tetramethylpiperidin-1-oxyl is preferred, and 2,2,6,6 tetramethylpiperidin-1-oxyl (TEMPO) is more preferred.

  The amount of the N-oxyl compound may be a catalytic amount, and is preferably 0.001 to 10% by mass, more preferably 0.01 to 9% by mass, and more preferably based on natural cellulose fiber (absolutely dry basis) Is 0.1 to 8% by mass, more preferably 0.5 to 5% by mass.

  In the oxidation treatment of natural cellulose fibers, an oxidizing agent can be used. As the oxidizing agent, from the viewpoint of solubility and reaction rate when the solvent is adjusted to an alkaline region, oxygen or air, peroxide; halogen, hypohalous acid, halogenous acid, perhalogenated acid and alkali metals thereof Salts or alkaline earth metal salts; halogen oxides, nitrogen oxides and the like can be mentioned. Among these, alkali metal hypohalites are preferable, and specifically, sodium hypochlorite and sodium hypobromous acid are exemplified. The use amount of the oxidizing agent may be selected according to the degree of carboxyl group substitution (oxidation degree) of the natural cellulose fiber, and the yield of the oxidation reaction is different depending on the reaction conditions. The preferred range is about 1 to 100% by mass with respect to the cellulose fiber (absolutely dry basis).

  In order to carry out the oxidation reaction more efficiently, bromides such as sodium bromide and potassium bromide, and iodides such as sodium iodide and potassium iodide can be used as a cocatalyst. The amount of cocatalyst is not particularly limited as long as it is an effective amount capable of exerting its function.

  The reaction temperature in the oxidation treatment is preferably 50 ° C. or less, more preferably 40 ° C. or less, still more preferably 20 ° C. or less, from the viewpoint of reaction selectivity and suppression of side reactions, and the lower limit is preferably −5. ° C or more.

  In addition, it is preferable to adjust the pH of the reaction system to the property of the oxidizing agent, for example, when sodium hypochlorite is used as the oxidizing agent, the pH of the reaction system is preferably on the alkaline side, preferably pH 7 to 13, More preferred is pH 10-13. The reaction time is preferably 1 to 240 minutes.

  By performing the oxidation treatment, a carboxy group-containing cellulose fiber having a carboxy group content of 0.1 mmol / g or more can be obtained.

(Purification process)
The carboxy group-containing cellulose fiber obtained by the oxidation reaction contains an N-oxyl compound such as TEMPO used as a catalyst and a by-product salt. Although the next step may be carried out as it is, purification may be carried out to obtain a carboxy group-containing cellulose fiber of high purity. As a purification method, an optimum method can be adopted according to the type of solvent in the oxidation reaction, the degree of oxidation of the product, and the degree of purification. For example, reprecipitation using water as a good solvent and methanol, ethanol, acetone etc. as a poor solvent, extraction of TEMPO etc. into a solvent phase-separated from water such as hexane, ion exchange of salts, purification by dialysis etc. It can be mentioned.

(Micronization process)
In the first production mode, a step of refining the carboxy group-containing cellulose fiber obtained in the step (1) is performed after the purification step. In the refining step, it is preferable to disperse the carboxy group-containing cellulose fiber which has been subjected to the purification step in a solvent to carry out a refining treatment. By performing this refining step, fine cellulose fibers having a number average fiber diameter in the above range can be obtained.

  The solvent as the dispersion medium is, besides water, an alcohol having 1 to 6 carbon atoms such as methanol, ethanol or propanol, preferably 1 to 3 carbon atoms; ketones having 3 to 6 carbon atoms such as acetone, methyl ethyl ketone or methyl isobutyl ketone Linear or branched saturated hydrocarbon having 1 to 6 carbon atoms or unsaturated hydrocarbon; aromatic hydrocarbon such as benzene and toluene; halogenated hydrocarbon such as methylene chloride and chloroform; lower hydrocarbon having 2 to 5 carbon atoms Examples thereof include polar solvents such as alkyl ether; N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, diesters of succinic acid and triethylene glycol monomethyl ether, and the like. These can be used alone or in combination of two or more, but from the viewpoint of the operability of the refining treatment, water, alcohols having 1 to 6 carbon atoms, ketones having 3 to 6 carbon atoms, and 2 carbon atoms And polar solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, methyl triglycol diester succinate, etc. are preferable, and water is more preferable from the viewpoint of environmental load reduction. The amount of the solvent used is not particularly limited as long as it is an effective amount capable of dispersing the carboxy group-containing cellulose fiber, and preferably 1 to 500 times by mass, more preferably 2 to 200 times the carboxy group-containing cellulose fiber. It is more preferable to use by mass.

  Moreover, as an apparatus used by refinement | miniaturization processing, a well-known disperser is used suitably. For example, a disintegrator, a disintegrator, a low pressure homogenizer, a high pressure homogenizer, a grinder, a cutter mill, a ball mill, a jet mill, a short screw extruder, a twin screw extruder, an ultrasonic stirrer, a household juicer mixer and the like can be used. Moreover, as for solid content concentration of the reactant fiber in refinement processing, 50 mass% or less is preferable.

  The form of the carboxy group-containing fine cellulose fiber obtained after the refining step is, if necessary, in the form of a suspension having a controlled solid concentration (visually colorless and transparent or opaque liquid) or a dry powder (but Or in the form of powder in which fine cellulose fibers are agglomerated, and does not mean cellulose particles). In the case of a suspension, only water may be used as a dispersion medium, and a mixed solvent of water and another organic solvent (for example, alcohols such as ethanol), a surfactant, an acid, a base, etc. You may use it.

  By such oxidation treatment and refinement treatment of a natural cellulose fiber, the hydroxyl group at the C6 position of the cellulose constitutional unit is selectively oxidized to a carboxy group via an aldehyde group, and the carboxy group content is 0.1 mmol / A cellulose fiber having a number average fiber diameter of not less than 0.5 nm and not more than 200 nm, an aspect ratio of preferably not less than 10 and not more than 1000, and a crystallinity of preferably not less than 30% is obtained. be able to. Here, the carboxy group-containing fine cellulose fiber has a cellulose type I crystal structure. This means that the carboxy group-containing fine cellulose fiber used in the present invention is a fiber obtained by surface oxidation and refining of a naturally occurring cellulose solid material having a type I crystal structure. In the step (1), after the oxidation treatment of natural cellulose fiber, an acid (for example, hydrochloric acid) can be further reacted to adjust the carboxy group content, and the reaction is carried out before and after the refinement treatment You may go to any of.

[Step (2A)]
In the first production mode, the step (2A) is a step of mixing the carboxy group-containing fine cellulose fiber obtained through the above-mentioned refining process and an amine having a modifying group to obtain a fine cellulose fiber composite. is there. Specifically, the carboxy group-containing fine cellulose fiber and an amine having a modifying group are mixed in a solvent.

  As an amine which has a modifying group used at a process (2A), the above-mentioned thing mentioned above in the fine cellulose fiber composite is mentioned.

  The amount of the amine to be used can be determined by the bonding amount of the desired amine salt in the fine cellulose fiber composite, but from the viewpoint of reactivity, 1 mol of carboxy group contained in the carboxy group-containing fine cellulose fiber, The amine group is preferably 0.01 mol or more, more preferably 0.1 mol or more, still more preferably 0.5 mol or more, still more preferably 0.7 mol or more, and in view of product purity, preferably 50 mol or less, more preferably Is used in an amount of 20 mol or less, more preferably 10 mol or less. In addition, the amine contained in the above range may be subjected to the reaction at once, or may be divided and subjected to the reaction. When the amine is a monoamine, the above-mentioned amine group and the amine are the same.

  As the solvent, it is preferable to select a solvent in which the amine to be used dissolves, for example, ethanol, isopropanol (IPA), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N, N-dimethylacetamide, tetrahydrofuran (THF), diesters of succinic acid and triethylene glycol monomethyl ether, acetone, methyl ethyl ketone (MEK), acetonitrile, dichloromethane, chloroform, toluene, acetic acid, water and the like, and one or more of these may be used alone or in combination Can be used in combination. Among these polar solvents, diesters of succinic acid and triethylene glycol monomethyl ether, ethanol, DMF and water are preferable.

  The temperature at the time of mixing is preferably 0 ° C. or more, more preferably 5 ° C. or more, still more preferably 10 ° C. or more, from the viewpoint of the reactivity of the amine. Further, from the viewpoint of coloring of the composite, it is preferably 50 ° C. or less, more preferably 40 ° C. or less, and still more preferably 30 ° C. or less. The mixing time can be appropriately set according to the type of amine and solvent to be used, but from the viewpoint of the reactivity of the amine, preferably 0.01 hours or more, more preferably 0.1 hours or more, still more preferably 1 It is time or more, preferably 48 hours or less, more preferably 24 hours or less.

  After the salt formation, post-treatment may be appropriately performed to remove unreacted amine and the like. As a method of the post-treatment, for example, filtration, centrifugation, dialysis and the like can be used.

  Moreover, about the manufacturing method of aspect B, since a process (1) can be performed similarly to the aspect A, it describes about the process (2B) in a 1st manufacture form below. Moreover, it can manufacture by the method of Unexamined-Japanese-Patent No. 2013-151661, for example.

[Step (2B)]
In the first production mode, in the step (2B), the carboxy group-containing fine cellulose fiber obtained through the above-mentioned refining process and the amine having a modifying group are amidated to obtain a fine cellulose fiber composite. It is a process. The mixing method is not particularly limited as long as the raw materials react with each other. Specifically, the raw materials are mixed in the presence of a condensing agent, and the carboxy group contained in the carboxy group-containing fine cellulose fiber And condensation reaction with the amino group of the amine having a modifying group to form an amide bond.

  As an amine which has a modifying group used at a process (2B), the above-mentioned thing mentioned above in the fine cellulose fiber composite is mentioned.

  In step (2B), the carboxy group-containing fine cellulose fiber and the amine having a modifying group are amidated in the presence of a condensing agent.

  The amount of the amine used is preferably 0.1 mol or more, more preferably 0.5 mol or more, based on 1 mol of carboxy group contained in the carboxy group-containing fine cellulose fiber, from the viewpoint of reactivity. From the viewpoint of product purity, the amount is preferably 50 mol or less, more preferably 20 mol or less, still more preferably 10 mol or less. In addition, the amine contained in the above range may be subjected to the reaction at once, or may be divided and subjected to the reaction.

  The condensing agent is not particularly limited, and examples thereof include condensing agents described in Synthetic Chemical Series Peptide Synthesis (Maruzen Co.) P116 or Tetrahedron, 57, 1551 (2001), and the like, for example, 4- (4,6- Dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (hereinafter sometimes referred to as "DMT-MM") and the like can be mentioned.

  In the above-mentioned amidation reaction, the solvent in the above-mentioned refinement process is mentioned, and it is preferred to choose the solvent in which the amine to be used dissolves.

  The reaction time and reaction temperature in the amidation reaction can be appropriately selected according to the type of amine and solvent used, etc., but from the viewpoint of the reaction rate, preferably 1 to 24 hours, more preferably 10 to 20 hours It is. The reaction temperature is preferably 0 ° C. or more, more preferably 5 ° C. or more, still more preferably 10 ° C. or more from the viewpoint of reactivity. In addition, from the viewpoint of coloring of the composite, it is preferably 200 ° C. or less, more preferably 80 ° C. or less, and still more preferably 30 ° C. or less.

  After the reaction, post-treatment may be appropriately performed to remove unreacted amine, condensing agent and the like. As a method of the post-treatment, for example, filtration, centrifugation, dialysis and the like can be used.

  In any of the embodiment A and the embodiment B, in the second production mode, each step described above is performed in the order of step (1), step (2A) or step (2B), and refinement step. , And in the same manner as in the first embodiment.

  Further, it may be a fine cellulose fiber composite obtained by combining aspect A and aspect B, that is, a fine cellulose fiber composite having a modifying group linked via an ionic bond and a modifying group linked via an amide bond. It may be the body. In this case, either step (2A) or step (2B) may be performed first.

  Thus, it is possible to obtain a fine cellulose fiber composite in which a modifying group is linked to the fine cellulose fiber via an ionic bond and / or an amide bond. In the present invention, in view of the strength of the resulting shaped article, a fine cellulose fiber composite in which the modifying groups are linked via an amide bond is preferred.

  The obtained fine cellulose fiber composite can be used in the state of a dispersion after the above-mentioned post-treatment, or it can be used in the form of a dry powder by removing the solvent from the dispersion by a drying treatment or the like. Fine cellulose fiber composites can also be obtained and used. Here, the “powder form” is a powder form in which a fine cellulose fiber complex is aggregated, and does not mean cellulose particles.

  As a powdery fine cellulose fiber composite, for example, a dried product obtained by drying the dispersion of the fine cellulose fiber composite as it is; a powder obtained by mechanical processing of the dried product; and a dispersion of the fine cellulose fiber composite The liquid may be powdered by a known spray drying method; and the dispersion of the fine cellulose fiber composite may be powdered by a known freeze drying method. The spray drying method is a method in which the dispersion of the fine cellulose fiber composite is sprayed in the air and dried.

  The fine cellulose fiber composite preferably has a number average fiber diameter of 0.5 nm or more, more preferably 0.8 nm or more, and still more preferably 1 nm or more, from the viewpoint of improving the strength of the resulting shaped article at high temperatures. is there. Moreover, it is preferably 200 nm or less, more preferably 100 nm or less, still more preferably 50 nm or less, still more preferably 20 nm or less, further preferably 10 nm or less, in view of the strength at high temperature of the obtained shaped article.

  The fine cellulose fiber composite has a degree of crystallinity similar to the degree of crystallinity of the fine cellulose fiber, since the degree of crystallinity is not reduced by the reaction of the step (2A) or the step (2B). Is preferred.

  As described above, the fine cellulose fiber composite contained in the resin composition of the present invention has a number average fiber diameter of 0.5 nm to 200 nm and a carboxyl group content of 0.1 mmol / g or more. A number average fiber diameter of 0.5 nm or more and 200 nm or less is preferable because the cellulose fiber is one in which a hydrocarbon group and / or an EO / PO copolymerized part is linked via an ionic bond and / or an amide bond. .

  The content of each component in the resin composition of the present invention is as follows.

  The content of the photocurable resin precursor in the resin composition of the present invention is preferably 50% by mass or more, more preferably 75% by mass or more, and 90% by mass or more from the viewpoint of strength and formability of the shaped article. More preferably, 93% by mass or more is more preferable. Moreover, from the same viewpoint, 99.9 mass% or less is preferable, 99 mass% or less is more preferable, and 98 mass% or less is still more preferable.

  The content of the fine cellulose fiber or the modified product thereof in the resin composition of the present invention is preferably 0. from the viewpoint of improving the heat resistance of the shaped article obtained relative to 100 parts by mass of the photocurable resin precursor. 01 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, still more preferably 1.0 parts by mass or more, still more preferably 2.0 parts by mass or more From the viewpoint, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, and still more preferably 7 parts by mass or less. In addition, content of the fine cellulose fiber here is content of the fine cellulose fiber in which the modifying group is not introduce | transduced.

  In addition, when the resin composition of the present invention contains a modified product of fine cellulose fibers, the content (converted amount) of the fine cellulose fibers is that of the shaped article obtained with respect to 100 parts by mass of the photocurable resin precursor. From the viewpoint of improving heat resistance, it is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, still more preferably 0.5 parts by mass or more, still more preferably 1.0 parts by mass or more From the viewpoint of the properties, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less, still more preferably 7 parts by mass or less.

  The content of the fine cellulose fiber or the modified product thereof in the resin composition of the present invention is preferably 0.01% by mass or more, more preferably 0.1% by mass from the viewpoint of improving the heat resistance of the resulting shaped article Or more, more preferably 0.5% by mass or more, still more preferably 1.0% by mass or more, still more preferably 2.0% by mass or more, and from the viewpoint of handleability, preferably 20% by mass or less, more preferably It is 15% by mass or less, more preferably 10% by mass or less, and further preferably 7% by mass or less.

  Moreover, the resin composition of this invention can use a photoinitiator as another component except the above.

  The photopolymerization initiator may be any known one, for example, acetophenones, benzophenones, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkylthiones, disulfide compounds And thiuram compounds, fluoroamine compounds and the like. The content of the photopolymerization initiator may be appropriately set according to the type of the photopolymerization initiator to be used.

  In the resin composition of the present invention, as components other than the above, a crystal nucleating agent, a filler (inorganic filler, organic filler), a hydrolysis inhibitor, a flame retardant, an antioxidant, a hydrocarbon wax and the like Lubricants, UV absorbers, antistatic agents, antifogging agents, light stabilizers, pigments, antifungal agents, antibacterial agents, foaming agents, surfactants, etc. which are anionic type surfactants do not impair the effects of the present invention It can be contained in the range. Moreover, it is also possible to add other polymeric materials and other resin compositions in the range which does not inhibit the effect of this invention. The content of the optional additive may be suitably within the range where the effect of the present invention is not impaired, but for example, about 10% by mass or less in the resin composition is preferable, and about 5% by mass or less is more preferable .

  The resin composition of the present invention can be prepared without particular limitation as long as it contains a photocurable resin precursor and a fine cellulose fiber or a modified product thereof. For example, a photocurable resin precursor and a fine cellulose fiber Or a modified product thereof, and further, if necessary, a raw material containing various additives, stirred with a Henschel mixer, an ultrasonic homogenizer, a high pressure homogenizer, etc., or a closed kneader, a single screw or twin screw extruder, an open roll kneader, etc. It can be prepared by melt-kneading or solvent casting using a known kneader. If necessary, a solvent (for example, ethanol) may be added and stirred, and then the solvent may be removed for preparation.

  The resin composition of the present invention is used for the production of a photocurable three-dimensional structure. As a method for preparing a photocurable three-dimensional structure, an inkjet ultraviolet curing method and an optical shaping method are known. In the inkjet ultraviolet curing method, after discharging a liquid resin composition, light is irradiated and cured to form a shape. On the other hand, in the optical shaping method, the surface of the pooled liquid resin composition is irradiated with light and then cured and shaped. Therefore, when applying the resin composition of this invention to these methods, it is preferable to use the resin composition which has the viscosity according to them.

  Specifically, when the resin composition of the present invention is used in an inkjet ultraviolet curing method, the resin composition of the present invention has a viscosity at 25 ° C. of 500 mPa ·· from the viewpoint of improving discharge from the nozzle of the ink cartridge. s or less is preferable, 300 mPa · s or less is more preferable, 150 mPa · s or less is more preferable, and 130 mPa · s or less is still more preferable. The lower limit is not particularly limited, but is preferably 1 mPa · s or more from the viewpoint of handleability. When the resin composition of the present invention is used in the optical shaping system, the resin composition of the present invention has a viscosity of 50 mPa · s at 25 ° C. from the viewpoint of stably maintaining the cured product in the resin composition. The above is preferable, 100 mPa · s or more is more preferable, 200 mPa · s or more is more preferable, from the viewpoint of handleability, 20000 mPa · s or less is preferable, 15000 mPa · s or less is more preferable, and 12000 mPa · s or less is still more preferable. In order to have the viscosity described above, in the present invention, for example, the viscosity can be increased by increasing the content of the fine cellulose fiber or its modified product, and the viscosity can be reduced by reducing the content. . Moreover, if the aspect ratio of the fine cellulose fiber to be used is large, the viscosity can be increased, and if the aspect ratio is small, the viscosity can be reduced. In the present specification, the viscosity is a value measured using a B-type viscometer.

  The resin composition of the present invention preferably has a specific gravity of 0.5 or more, more preferably 0.8 or more, and still more preferably 1.0 or more, from the viewpoint of improving the strength of the shaped article. There is no particular upper limit, but it may be 2.0 or less. Here, the specific gravity means the ratio to the mass of 4 ° C. water of the same volume, and can be measured according to the method described in JIS Z 8804.

  The resin composition of the present invention has good handleability, and the resulting molded article exhibits good strength at high temperatures, so products such as precision instruments, electric / electronic products, automobiles, etc. or parts or chassis thereof Can be suitably used as a material in three-dimensional modeling. Therefore, the present invention also provides a method for producing an optically shaped article, characterized in that the resin composition of the present invention (the photocurable composition of the present invention) is used for an optical shaping apparatus.

[Manufacturing method of a photofabricated object]
The method for producing an optically formed article of the present invention is not particularly limited as long as the photocurable composition of the present invention is used for an optical shaping apparatus. A publicly known thing can be used as an optical shaping apparatus, The photocurable composition of this invention is applied according to the specification of the apparatus, According to the said technical field, light is irradiated according to the said technical field, and the photocurable composition of this invention is made By curing, a photofabricated object can be prepared. As light which can be irradiated, ultraviolet light, electron beam, X-ray, radiation, high frequency and the like can be used. The application of the photocurable composition and the curing by light irradiation can be repeated.

  Specifically, for example, in the case of producing a part or a housing by using the photocurable composition of the present invention by the inkjet method, the photocurable composition is filled in the cartridge of the inkjet device, and the desired shape is obtained from the nozzle And a light is irradiated to form a cured product layer, and then the discharge and light irradiation are repeated on the layer to obtain a cured product layer.

  The photofabricated product of the photocurable composition of the present invention thus obtained is excellent in mechanical strength and exhibits good strength at high temperatures. Therefore, the present invention is also directed to a photocurable composition of the present invention. Provide a light-shaped object of The photofabricated article of the present invention can be suitably used for various applications mentioned for the photocurable composition described above, since the photocurable composition of the present invention is photomolded.

  Hereinafter, the present invention will be specifically described by way of examples. Note that this example is merely an example of the present invention and does not mean any limitation. Parts in the examples are parts by weight unless otherwise stated. In addition, "atmospheric pressure" shows 101.3 kPa and "normal temperature" shows 25 degreeC.

[Number-average fiber diameter of fine cellulose fibers]
Water is added to a fine cellulose fiber to prepare a dispersion having a concentration of 0.0001% by mass, and the dispersion is dropped onto mica (mica) and dried to obtain an atomic force microscope (observation sample). AFM, Nanoscope III Tapping mode AFM, manufactured by Digital instrument, and using a point probe (NCH) manufactured by Nanosensors Co., Ltd.) are used to measure the fiber height of the cellulose fiber in the observation sample. At that time, in a microscope image in which the cellulose fibers can be confirmed, five or more fine cellulose fibers are extracted, and the number average fiber diameter is calculated from the height of those fibers.

[Aspect ratio of fine cellulose fiber]
The average aspect ratio is determined from the relationship between the concentration of cellulose fibers in the dispersion and the specific viscosity of the dispersion to water, by back-calculating the aspect ratio of the cellulose fibers according to the following equation (1). In addition, following formula (1) is the The Theory of Polymer Dynamics, M. DOI and D. F. The relationship between the viscosity equation (8.138) of a rigid rod molecule described in EDWARDS, CLARENDON PRESS OXFORD, 1986, P. 312 and Lb ² × ρ = M / N _A , wherein L is the fiber length and b is the fiber width (The cellulose fiber cross section is square), ρ is the concentration of cellulose fiber (kg / m ³ ), M is the molecular weight, and N _A is the Avogadro number. In the above viscosity formula (8.138), the rigid rod-like molecule is cellulose fiber. In the following formula (1), η _SP is a specific viscosity, π is a circle ratio, ln is a natural logarithm, P is an aspect ratio (L / b), γ = 0.8, and _{S S} is a density of the dispersion medium (kg / m ³ ), ρ ₀ is the density of cellulose crystals (kg / m ³ ), and C is the mass concentration of cellulose (C = ρ / ρ _S ).

[Carboxyl group content of fine cellulose fiber and fine cellulose fiber composite]
A dry mass of 0.5 g of fine cellulose fiber or fine cellulose fiber complex is placed in a 100 mL beaker, and ion-exchanged water or a mixed solvent of methanol / water = 2/1 is added to make a total of 55 mL, and there is 0.01 M sodium chloride aqueous solution 5 mL is added to prepare a dispersion, and the dispersion is stirred until the fine cellulose fiber or fine cellulose fiber composite is sufficiently dispersed. The pH is adjusted to 2.5 to 3 by adding 0.1 M hydrochloric acid to this dispersion, and a 0.05 M aqueous solution of sodium hydroxide is added using an automatic titrator (trade name "AUT-50" manufactured by Toa DK Co., Ltd.). The solution is dropped on the dispersion under the condition of a waiting time of 60 seconds, the value of the conductivity and pH is measured every minute, and the measurement is continued until the pH becomes around 11, to obtain a conductivity curve. The sodium hydroxide titration amount is determined from the conductivity curve, and the carboxy group content of the fine cellulose fiber or the fine cellulose fiber composite is calculated by the following equation.
Carboxy group content (mmol / g) = sodium hydroxide titer × sodium hydroxide aqueous solution concentration (0.05 M) / mass of cellulose fiber (0.5 g)

Preparation Example 1 of Fine Cellulose Fiber (Dispersion of Carboxy Group-Containing Fine Cellulose Fiber (Long Fiber) Obtained by reacting N-oxyl Compound with Natural Cellulose)
Softwood bleached kraft pulp (Fletcher Challenge Canada, trade name "Machenzie", CSF 650 ml) was used as a natural cellulose fiber. As TEMPO, a commercial item (manufactured by ALDRICH, Free radical, 98% by mass) was used. A commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) was used as sodium hypochlorite. A commercially available product (manufactured by Wako Pure Chemical Industries, Ltd.) was used as sodium bromide.

  First, 100 g of softwood bleached kraft pulp fiber is sufficiently stirred with 9900 g of ion-exchanged water, and then, with respect to 100 g of the pulp mass, 1.25 mass% of TEMPO, 12.5 mass% of sodium bromide, sodium hypochlorite 28 .4 wt% were added in this order. The pH was kept at 10.5 by dropwise addition of 0.5 M sodium hydroxide using a pH stud. The reaction was carried out for 120 minutes (20 ° C.), after which the dropping of sodium hydroxide was stopped to obtain an oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion exchange water and then subjected to a dehydration treatment. After that, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water are finely divided twice at 245 MPa using a high-pressure homogenizer (Starburst Lab HJP-2505 manufactured by Sugino Machine Co., Ltd.) to obtain carboxy group-containing fine cellulose fiber A dispersion (solid concentration: 1.3% by mass) was obtained. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the carboxy group content was 1.6 mmol / g, and the aspect ratio was 300.

Preparation Example 2 of Fine Cellulose Fiber (Dispersion of Carboxyl-Containing Fine Cellulose Fiber (Short Fiber))
In a beaker, 100 g (solid content concentration: 1.3% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 1 of fine cellulose fiber is further subjected to 50 times of refinement treatment at 245 MPa using a high pressure homogenizer, A group-containing fine cellulose fiber dispersion (solid content concentration: 1.3% by mass) was obtained. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the carboxy group content was 1.6 mmol / g, and the aspect ratio was 50.

Preparation Example 3 of Fine Cellulose Fiber (Carboxyl Group-Containing Fine Cellulose Fiber (Long Fiber) Dispersion Obtained by Acid Type Treatment)
A carboxy group-containing fine cellulose fiber dispersion of 4088.75 g (solid content concentration: 1.3 mass%) obtained in Preparation Example 1 of fine cellulose fibers and 4085 g of ion-exchanged water are added to a beaker to make a 0.5 mass% aqueous solution, The mixture was stirred at room temperature (25 ° C.) for 30 minutes with a mechanical stirrer. Subsequently, 245 g of a 1 M aqueous hydrochloric acid solution was charged, and allowed to react at room temperature for 1 hour. After completion of the reaction, the reaction solution was reprecipitated with acetone, filtered, and then washed with acetone / ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added and the mixture was filtered to obtain an acetone-containing acid type cellulose fiber dispersion (solid content concentration: 5.0% by mass) in a state where the carboxy group-containing fine cellulose fiber was swollen in acetone. After completion of the reaction, the reaction solution was filtered and then washed with ion exchanged water to remove hydrochloric acid and salts. After solvent substitution with acetone, solvent substitution is carried out with dimethylformamide (DMF) to obtain a DMF-containing acid type cellulose fiber dispersion (solid content concentration: 5.4% by mass) in a state where the carboxy group-containing fine cellulose fiber is swollen. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the carboxy group content was 1.6 mmol / g, and the aspect ratio was 300.

Preparation Example 4 of Fine Cellulose Fiber (Carboxyl Group-Containing Fine Cellulose Fiber (Short Fiber) Dispersion Obtained by Acid Type Treatment)
In a beaker, add 4088.75 g (solid content concentration: 1.3% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 2 of the fine cellulose fiber and 4085 g of ion exchanged water to obtain a 0.5% by mass aqueous solution The mixture was stirred at room temperature (25 ° C.) for 30 minutes with a mechanical stirrer. Subsequently, 245 g of a 1 M aqueous hydrochloric acid solution was charged, and allowed to react at room temperature for 1 hour. After completion of the reaction, the reaction solution was reprecipitated with acetone, filtered, and then washed with acetone / ion-exchanged water to remove hydrochloric acid and salts. Finally, acetone was added and the mixture was filtered to obtain an acetone-containing acid type cellulose fiber dispersion (solid content concentration: 5.0% by mass) in a state where the carboxy group-containing fine cellulose fiber was swollen in acetone. After completion of the reaction, the reaction solution was filtered and then washed with ion exchanged water to remove hydrochloric acid and salts. After solvent substitution with acetone, solvent substitution is carried out with dimethylformamide (DMF) to obtain a DMF-containing acid type cellulose fiber dispersion (solid content concentration: 6.4 mass%) in a state where the carboxy group-containing fine cellulose fiber is swollen. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the carboxy group content was 1.6 mmol / g, and the aspect ratio was 50.

Production Example 1 of Fine Cellulose Fiber Complex (Examples 1 to 4, 9, 10, 13, 19)
In a beaker equipped with a magnetic stirrer and a stirrer, 35 g (solid content concentration: 5.4% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 3 of the fine cellulose fiber was charged. Subsequently, an amine of the type shown in Table 1, 2 or 4 was added in an amount corresponding to 1.0 mol of amine group to 1 mol of carboxy group of the fine cellulose fiber, 4- (4,6-dimethoxy- 1,3,5-Triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM) in an amount corresponding to 2.2 mol per mol of carboxy groups of fine cellulose fiber, N-methylmorpholine (NMM) ) Was charged in an amount corresponding to 1.2 mol with respect to the carboxy group of the fine cellulose fiber, dissolved in 300 g of DMF, and the reaction solution was reacted at room temperature (25 ° C.) for 14 hours. After completion of the reaction, the reaction product is filtered, washed with ion-exchanged water, DMT-MM salt is removed, and washing with ethanol and solvent substitution are carried out to obtain a fine cellulose fiber complex in which amines are linked to fine cellulose fibers via amide bonds. Obtained.

Production Example 2 of Fine Cellulose Fiber Composite (Examples 5 to 8, 11 and 12)
In a beaker equipped with a magnetic stirrer and a stirrer, 35 g (solid content concentration: 6.4% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 4 of the fine cellulose fiber was charged. Subsequently, an amine of the type shown in Table 1 or 2 is added in an amount corresponding to 1.0 mol of amine group to 1 mol of carboxy group of the fine cellulose fiber, and DMT-MM as a condensing agent is 1 mol of carboxy group of the fine cellulose fiber. The amount corresponding to 2.2 mol and the amount corresponding to 1.2 mol with respect to the carboxy group of the fine cellulose fiber are respectively charged and dissolved in 300 g DMF, and the reaction solution is reacted at room temperature (25 ° C.) for 14 hours I did. After completion of the reaction, the reaction product is filtered, washed with ion-exchanged water, DMT-MM salt is removed, and washing with ethanol and solvent substitution are carried out to obtain a fine cellulose fiber complex in which amines are linked to fine cellulose fibers via amide bonds. Obtained.

Production Example 3 of Fine Cellulose Fiber Composite (Examples 15 to 17 and 20)
In a beaker equipped with a magnetic stirrer and a stirrer, 35 g (solid content concentration: 5.4% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 3 of the fine cellulose fiber was charged. Subsequently, the amine shown in Table 3 or 4 is charged in an amount corresponding to 1.0 mol of amine group to 1 mol of carboxy group of the fine cellulose fiber, and dissolved in 300 g of ion exchanged water. The reaction was allowed to proceed for 14 hours. After completion of the reaction, the reaction solution was filtered, washed with ion exchanged water, washed with ethanol and solvent-replaced to obtain a fine cellulose fiber complex in which an amine is connected to the fine cellulose fiber via an ionic bond.

Production Example 4 of Fine Cellulose Fiber Composite (Example 14)
In a beaker equipped with a magnetic stirrer and a stirrer, 35 g (solid content concentration: 5.4% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 3 of the fine cellulose fiber was charged. Subsequently, aniline is equivalent to 1.5 mol of amine group to 1 mol of carboxy group of fine cellulose fiber, DMT-MM as a condensing agent is 2.5 mol to 1 mol of carboxy group of fine cellulose fiber The amount and NMM were respectively charged in an amount corresponding to 1.4 mol with respect to the carboxyl group of the fine cellulose fiber, dissolved in 300 g of DMF, and the reaction solution was reacted at room temperature (25 ° C.) for 14 hours. After completion of the reaction, the reaction product is filtered, washed with ion-exchanged water, DMT-MM salt removed, washed with ethanol and solvent-replaced, and a fine cellulose fiber composite in which phenyl groups are linked to fine cellulose fibers via an amide bond. I got a body.
<EOPO group modification>
An amine having an EO / PO copolymer part (M-2070, manufactured by Mitsui Chemicals Fine) with respect to 10 g of the obtained fine cellulose fiber composite dispersion (solid content concentration: 5.0% by mass), the carboxy of the fine cellulose fiber An amount corresponding to 0.06 mol of an amine group was added to 1 mol of a group, dissolved in 100 g of ion exchanged water, and the reaction solution was allowed to react at room temperature (25 ° C.) for 14 hours. After completion of the reaction, filtration is carried out, washing is carried out with ion exchange water, washing with ethanol and solvent substitution are carried out, whereby a fine cellulose fiber is connected to an EOPO copolymer via an ionic bond and a phenyl group via an amide bond. The complex was obtained.

Examples 1 to 17
<Acrylic resin composition>
50 g (100 parts by mass) of OBJET FULL CURE 720 (acrylic resin composition precursor manufactured by Stratasys, Inc.) as a photocurable resin precursor, the amount of the fine cellulose fiber composite shown in Tables 1 to 3 shown in Tables 1 to 3 Add 20 g of ethanol to a beaker, stir for 2 minutes with an ultrasonic homogenizer (US-300E, manufactured by Nippon Seiki Seisakusho Co., Ltd.), and then, at 100 MPa with a high pressure homogenizer (Sugino Machine, Starburst Lab HJP-25005) Two passes, one pass was finely processed at 150 MPa. The homogeneous mixture was poured into a glass petri dish and vacuum dried at 50 ° C. for 24 hours to remove the solvent component in the mixture, thereby producing a resin composition containing 0.1 parts by mass of a fine cellulose fiber composite. The specific gravity and the viscosity of the obtained resin composition are shown in Tables 1 to 3.
The viscosity is analyzed using a viscometer (Viscometer TV-35) and a temperature control unit (Viscomate VM-150III) manufactured by Toki Sangyo Co., Ltd. under conditions of 25 ° C. measurement time, 1 minute measurement time, 1 rpm rotation speed, and rotor T1. The The specific gravity was measured using a 10 mL pycnometer according to the method described in JIS Z 8804.

<Curing of acrylic resin composition>
The resulting resin composition was uniformly coated on a polyimide film to a thickness of about 0.4 mm using a bar coater, and then a UV irradiation apparatus (Fusion Japan-type Light Hammer 10, light source: H bulb manufactured by Heraeus) was used. Using a lamp height of 67 mm, a belt speed of 15.8, and an output of 90% (approximately 94 mJ / cm ^{2 of} radiation), UV irradiation after nitrogen substitution to cure the resin allows the fine cellulose fiber composite to be 0 A photofabricated product of an acrylic resin composition containing 1 part by mass was obtained. Nitrogen substitution was performed by setting an inert box in a nitrogen substitution apparatus and substituting for 1 minute.

Example 18
A resin composition and a resin composition were prepared in the same manner as in Example 1, except that the DMF-containing acid type cellulose fiber dispersion obtained in Preparation Example 3 was used instead of the fine cellulose fiber composite and the compounding amount was changed as shown in Table 3. A photofabric of the composition was produced.

Comparative Example 1
A resin composition and a photofabricated product of the composition were produced in the same manner as in Example 1 except that the fine cellulose fiber composite was not used.

Examples 19 to 20 (epoxy resin)
The photocurable resin precursor to be used was changed to SCR 774 (epoxy resin composition precursor) manufactured by DMEC, and the type and amount of the fine cellulose fiber composite to be used were changed as shown in Table 4 A resin composition and a photofabricated product of the composition were produced in the same manner as in Example 1.

Comparative example 2
A resin composition and a photofabricated product of the composition were produced in the same manner as in Example 19 except that the fine cellulose fiber composite was not used.

In addition, the raw material in Tables 1-4 is as follows.
[Photo-curable resin precursor]
OBJET FULL CURE 720: acrylic resin composition precursor, manufactured by Stratasys, SCR 774 for inkjet 3D printer: epoxy resin composition precursor, manufactured by DMEC, for stereolithography 3D printer [amine]
EOPO amine: Jeffamine M-2070, manufactured by HUNTSMAN, EO / PO (molar ratio) 32/10
C18 amine: stearylamine (octadecylamine), Tokyo Chemical Industry Co., Ltd. C12 amine: dodecylamine, Wako Pure Chemical Industries TBAH: tetrabutylammonium hydroxide (tetrabutylammonium hydroxide), Wako Pure Chemical Industries aniline: aniline Wako Pure Chemical Industries Made

  The properties of the resulting light-shaped object (shaped object) were evaluated according to the method of Test Example 1 below. The results are shown in Tables 1 to 4.

Test Example 1 (storage elastic modulus)
Using a dynamic viscoelastic device (trade name "DMS 6100" manufactured by SII), a strip-shaped sample having a width of 5 mm and a length of 20 mm under nitrogen atmosphere at a frequency of 1 Hz from -50 ° C to 250 ° C for 1 minute The temperature was increased at a rate of 2 ° C. and measured in the tension mode. The storage elastic modulus number used the value of 100 degreeC (acrylic resin) or 200 degreeC (epoxy resin). The larger the value of the storage elastic modulus, the better the mechanical strength, and in the case of the acrylic resin composition, it is preferably 6 MPa or more, and in the case of the epoxy resin composition, it is preferably 90 MPa or more.

  As apparent from the results shown in Tables 1 to 4, the resin compositions obtained in the examples have a viscosity that is better in handleability than the compositions of the comparative examples, and light obtained by photocuring It can be seen that the shaped object develops strength at a high temperature (90 ° C. or higher for FullCure 720 and 180 ° C. or higher for SCR 774) at a temperature higher than Tg as compared with the optical shaped object obtained in the comparative example.

<Acrylic resin precursor composition>
An EOPO amine (Mitsui Chemical Fine, M-2070) obtained in the same manner as in Production Example 2 of a fine cellulose fiber composite has a solid content of 0.5 g, and the fine cellulose fiber composite is connected via an amide bond. The solution was placed in a beaker so that 50 g of FullCure 720 (manufactured by Stratasys, acrylic resin composition) and 20 g of ethanol were sequentially added as a photocurable resin precursor, and the mixture was added to an ultrasonic homogenizer (US-300E, manufactured by Nippon Seiki Co., Ltd.) The mixture is stirred for 2 minutes, and finely treated at 100 MPa for 2 passes and high pressure homogenizer (made by Sugino Machine Co., Ltd., Starburst Lab HJP-25005) for 1 pass at 150 MPa for 2 passes. The homogeneous mixture is poured into a glass petri dish and vacuum-dried at 50 ° C. for 24 hours to remove the solvent component in the mixture, thereby producing a resin composition containing 1 part by mass of the fine cellulose fiber composite.

<Production of an optically shaped object using an inkjet type optical shaping apparatus>
The obtained resin composition is filled in an ink cartridge (Dimatix DMP-2831) manufactured by FUJIFILM Corporation, the cartridge temperature is set to 70 ° C., and a waveform pattern of Dimatix standard pattern is inputted and discharged. After that, using a UV irradiation device (Light Hammer 10 made by Fusion Japan, a light source is a H bulb made by Heraeus), the lamp height is set to 67 mm, the belt speed 15.8, and the output 90% (radiant light amount approx. 94 mJ / cm ² ) After the nitrogen substitution, UV irradiation is performed to cure the resin, whereby a heat-resistant thin-film photoshaped object made of an acrylic resin composition containing 1 part by mass of a fine cellulose fiber composite can be obtained. In addition, by repeating the above process a predetermined number of times, it is possible to obtain a heat-resistant photofabricated object having a three-dimensional thickness.

  The photocurable composition for three-dimensional shaping of the present invention can be suitably used as a material for three-dimensional shaping of products such as precision instruments, electric / electronic products and automobiles, or parts or casings thereof.

Claims (10)

A) photocurable resin precursor, and B) fine cellulose fiber having a number average fiber diameter of 0.5 nm to 200 nm and a carboxy group content of 0.1 mmol / g or more and / or a modified product thereof A photocurable composition for three-dimensional shaping , wherein the modified product of the fine cellulose fiber is a carboxy group of a fine cellulose fiber having a hydrocarbon group or an ethylene oxide / propylene oxide (EO / PO) copolymerized part A photocurable composition which has been introduced . Fine cellulose fibers, natural cellulose fibers is a carboxy-containing cellulose textiles oxidized in the presence of N- oxyl compound, according to claim 1 photocurable composition. The photocurable composition according to claim 1 or 2 , wherein the introduction of the hydrocarbon group or the ethylene oxide / propylene oxide (EO / PO) copolymerized part is via an amide bond and / or an ionic bond. The light according to any one of claims 1 to 3 , wherein the photocurable resin precursor A) is one or more selected from the group consisting of an acrylic resin, a (meth) acrylic resin, and an epoxy resin. Curable composition. B) The content of fine cellulose fibers and / or reformate, A) with respect to the light curable resin precursor 100 parts by mass, not more than 20 parts by mass or more 0.01 part by weight, any claim 1-4 Or the photocurable composition described. The photocurable composition according to any one of claims 1 to 5, which has a viscosity of 1 mPa · s to 500 mPa · s at 25 ° C. The photocurable composition according to any one of claims 1 to 5, which has a viscosity of 50 mPa · s or more and 20000 mPa · s or less at 25 ° C. The photocurable composition according to any one of claims 1 to 7, which has a specific gravity of 0.5 or more and 2.0 or less. The photoshaped article which hardened | cured the photocurable composition in any one of Claims 1-8. A method for producing an optically shaped article, comprising using the photocurable composition according to any one of claims 1 to 8 in an optical shaping apparatus.