JP7086679B2 - Complex and its manufacturing method - Google Patents

Description

The present invention relates to a complex and a method for producing the complex.

Cellulose is a main component of plant cell walls and plant fibers, and is a natural polymer in which a large number of β-glucose molecules are linearly polymerized by glycosidic bonds, so that the environmental load is small. In this cellulose fiber, single cellulose nanofibers having a width of 3 to 4 nm, which is a basic unit, are bundled to form cellulose nanofibers having a width of 10 to 20 nm, which is a basic unit in a cell wall, and the thickness is further increased. It has a structure of several tens of μm bundles.

In recent years, these cellulose nanofibers have been found to have excellent properties such as high elastic modulus, high strength, low linear expansion coefficient, and gas barrier properties, and are lighter than glass fibers, carbon fibers, and inorganic fillers. Therefore, research and development are being carried out assuming various uses such as resin reinforcing materials, paint additives, films, and thickeners.

As a method for producing cellulose nanofibers, a method of mechanically defibrating using a high-pressure disperser or a grinder, or a method of chemically hydrophilizing pulp with a cationizing agent and then mechanically deflating using a kneader, etc. Examples thereof include a method of defibrating, a method of partially oxidizing using a TEMPO catalyst and the like to facilitate chemical defibration.

By the way, cellulose nanofibers are rarely used alone, and are generally used in combination with organic components and organic solvents. Since cellulose constituting the cellulose nanofibers has a large number of hydroxyl groups of glucose molecules, there is a problem that hydrogen bonds between the hydroxyl groups are likely to occur, and as a result, aggregation of the cellulose nanofibers is likely to occur. Further, as described above, since cellulose has a large number of hydroxyl groups on its surface, it has a problem that it has extremely high hydrophilicity and lacks affinity with an organic solvent which is hydrophobic.

That is, although cellulose nanofibers exist stably in water, it is difficult to combine them with hydrophobic polymers or hydrolyzable polymers (particularly melt-kneading) in a state containing a large amount of water. On the other hand, when dried, it aggregates and becomes a relic in the polymer, which deteriorates the characteristics, so that there is a problem that it is difficult to exhibit the characteristics possessed by the nanofibers in the polymer.

In order to solve this problem, a method of hydrophobizing cellulose nanofibers has been studied, but most of the methods have a method of substituting a hydroxyl group of cellulose nanofibers with a hydrophobic substituent by a chemical method. In addition to being costly, such a method has a problem that aggregation due to hydrogen bonds cannot be suppressed because only a part of the hydroxyl group is replaced.

Although ordinary cellulose fibers have the same problems, it can be said that they are particularly prominent in cellulose nanofibers in which many hydroxyl groups are exposed on the surface with respect to the weight.

In view of the above circumstances, an object of the present invention is to improve the strength of the resin composition by hydrophobizing the cellulose by a method other than substituting the hydroxyl group of the cellulose with a hydrophobic substituent. Is to provide a possible complex.

As a result of diligent research to achieve the above object, the present inventors have provided a conventional epoxy-based resin layer having a predetermined chemical structure on the surface of cellulose without chemically modifying the cellulose. It has been found that a composite having a performance equal to or higher than that of a composite for reinforcing a resin can be obtained. The present inventors have further studied based on such findings, and have completed the present invention.

That is, the present invention provides the following complex.
Item 1.
It has cellulose and an epoxy resin layer that covers a part or all of the surface of the cellulose.
The epoxy compound contained in the epoxy-based resin layer is a complex characterized by having one epoxy group.
Item 2.
Item 2. The complex according to Item 1, wherein the epoxy compound has a molecular weight of 350 or less.
Item 3.
Item 2. The complex according to Item 1 or 2, wherein the structural formula of the epoxy compound has an aromatic ring.
Item 4.
Item 3. The complex according to Item 3, wherein the aromatic ring has an aliphatic substituent.
Item 5.
Item 6. The complex according to any one of Items 1 to 4, wherein the epoxy compound has both the groups represented by the following general formulas (1) and (2) in the structural formula.

（式中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、任意の置換基又は水素原子を表わす。）

(In the equation, R ¹ , R ² and R ³ each independently represent an arbitrary substituent or hydrogen atom.)

Item 6.
Item 2. The complex according to Item 1 or 2, wherein the epoxy compound has an ether structure, and the ether structure has only the ether structure represented by the general formula (1).
Item 7.
Item 6. The complex according to any one of Items 1 to 6, wherein the cellulose is a cellulose nanofiber having a diameter of 3 to 1000 nm.
Item 8.
Item 2. The complex according to any one of Items 1 to 7, which contains 2 to 100 parts by mass of the epoxy compound with respect to 100 parts by mass of the cellulose.
Item 9.
A composition comprising the complex according to any one of Items 1 to 8 in an organic solvent.
Item 10.
Item 9. The composition according to Item 9, wherein the organic solvent has a boiling point of 110 ° C. or higher.
Item 11.
Item 9. The composition according to Item 9 or 10, wherein the organic solvent does not have a hydroxyl group.
Item 12.
Item 2. The composition according to any one of Items 9 to 11, further comprising water, wherein the content of the water in the composition is 10% by mass or less in 100% by mass of the composition.
Item 13.
A resin composition containing the complex and resin according to any one of Items 1 to 8.
Item 14.
Item 3. The resin composition according to Item 13, wherein the resin is at least one selected from the group consisting of polyester-based resins, polyamide-based resins, and polycarbonate-based resins.
Item 15.
Item 3. The resin composition according to Item 13, wherein the resin is at least one selected from the group consisting of biomass plastics and microbially produced plastics.
Item 16.
Item 13. The resin is one or more selected from the group consisting of polylactic acid, polyamide 4, polyamide 11, polybutylene succinate, polyhydroxybutyrate, and a copolymer containing these structures. Resin composition.
Item 17.
A method for producing a complex having cellulose and an epoxy-based resin layer that covers a part or the whole of the surface of the cellulose.
A production method comprising the step 1 of adding an epoxy resin layer forming solution containing an epoxy compound having one epoxy group and an organic solvent to the cellulose.
Item 18.
The epoxy resin layer forming solution further contains water and
Item 17. The production method according to Item 17, further comprising step 2 of removing water in the epoxy-based resin layer forming solution by heating and / or depressurizing after the step 1.

According to the complex according to the present invention, it is possible to provide a complex capable of improving the strength of the resin composition without chemically modifying the surface of cellulose.

(1. Complex)
The composite of the present invention is characterized by having a cellulose and an epoxy-based resin layer that covers a part or the whole of the surface of the cellulose, and the epoxy compound contained in the epoxy-based resin layer has one epoxy group. And.

(1.2. Cellulose)
As the cellulose, known ones can be widely adopted, and there is no particular limitation. Further, any of plant-derived cellulose, animal-derived cellulose, and bacterial-derived cellulose nanofibers can be preferably used. These may be used individually by 1 type, or may be used in combination of 2 or more type.

Plant-derived cellulose includes, for example, hardwood-derived cellulose (eucalyptus, poplar, etc.), conifer-derived cellulose (pine, fir, cedar, hinoki, etc.), herbaceous-derived cellulose (wara, bagasse, yoshi, kenaf, abaca, sisal, etc.). , And seed hair fiber (cotton, etc.) can be selected. The raw material pulp may be mechanical pulp obtained by mechanically processing wood chips, chemical pulp obtained by chemically removing non-cellulose components from wood chips, and dissolving pulp obtained by removing non-cellulose components. It may be pulp.

In addition, cellulose derived from animals such as sea squirts, cellulose derived from bacteria such as nata de coco, and the like can be used. Further, the cellulose does not necessarily have to be composed of only a pure cellulose component, and a non-cellulose component may be attached to the cellulose as the main component. Of course, it may be composed only of a pure cellulose component.

The main non-cellulose component attached to the cellulose nanofiber is not particularly limited, and can be appropriately selected depending on the use of the complex. For example, hemicellulose and lignin can be mentioned. The larger the amount of hemicellulose, the easier it is to deflate during the production of cellulose nanofibers, but the elastic modulus of the obtained resin composition tends to decrease. The greater the amount of lignin, the more difficult it is to deflate during the production of cellulose nanofibers, but since it has a phenolic hydroxyl group, it tends to react with the aromatic epoxy described later to cause a desirable cross-linking reaction during the production of the composite.

Further, the ratio of the pure cellulose component in the cellulose may be appropriately set according to the use of the complex. For example, when the complex is used for the purpose of resin reinforcement, the pure cellulose component ratio is 70% by mass or more in 100% by mass of cellulose in order to effectively utilize the strength characteristics of the cellulose component. Is preferable, and 80% by mass or more is more preferable. The upper limit of the ratio of pure cellulose components can be 100% by mass. In the present specification, the cellulose ratio is defined as the ratio of a pure cellulose component in which β-glucose molecules are linearly polymerized by glycosidic bonds with respect to 100% by mass of the total mass of cellulose.

The degree of polymerization of the pure cellulose component contained in the cellulose may be appropriately set according to the use of the complex. The lower the degree of polymerization of the cellulose component contained in the cellulose, the easier it is for the cellulose to be defibrated. On the other hand, the higher the degree of polymerization of the cellulose component contained in cellulose, the higher the elastic modulus of the complex and the composition can be obtained. In order to obtain a high-strength resin composition, it is preferable to use a cellulose component having a degree of polymerization of 500 or more, and it is more preferable to use a cellulose component having a degree of polymerization of 600 or more. The upper limit of the degree of polymerization of the cellulose component is not particularly limited, but is preferably 100,000, for example.

Regarding the degree of crystallinity of the pure cellulose component contained in cellulose, the lower the crystallinity, the easier it is for the cellulose to be defibrated, but the higher the crystallinity, the higher the elastic modulus and the composition can be obtained. In order to obtain a high-strength composition, the crystallinity of the pure cellulose component contained in cellulose is preferably 60% or more, and more preferably 70% or more. The upper limit of the crystallinity of cellulose is not particularly limited, but is preferably 99%, more preferably 98%, for example. Examples of the crystal structure of the cellulose component include type I, type II, type III, and type IV, and among them, from the viewpoint of reinforcing the resin, it is a cellulose component having a type I crystal structure having a high elastic modulus. Is preferable.

Cellulose fibers contained in pulp are usually 10 to 100 μm in diameter, but the cellulose nanofibers used in the present invention are preferably finely divided into fibers having a diameter of 1 to 10 μm in the circumferential cross section. Cellulose nanofibers are more preferred. More specifically, cellulose nanofibers having a diameter of 3 to 1000 nm are more preferable, and cellulose nanofibers having a diameter of 3 to 100 nm are even more preferable. However, not all of them need to be miniaturized, and some of them may be used. In this specification, the diameter of the cellulose nanofibers is defined as the median diameter obtained by observing 50 or more randomly selected cellulose nanofibers by SEM.

In general, it is considered that cellulose is ideally miniaturized without impairing its length, crystallinity, and degree of polymerization, and the strength of the obtained resin composition is exhibited when it is ideally dispersed. However, in reality, it is assumed that the thinner and longer the nanofibers are, the more they aggregate and the strength of the resin composition cannot be obtained. Further, since there are cases where the length, crystallinity, and degree of polymerization of the nanofibers are reduced by miniaturizing to the nano size, the appropriate degree of miniaturization differs depending on the purpose and the means for miniaturization.

As a method for refining cellulose, a known method can be widely adopted, and there is no particular limitation. Specifically, physical methods such as a high-pressure homogenizer method, an underwater counter-collision method, a grinder method, a ball mill method, and a biaxial kneading method may be used, and chemistry using a TEMPO catalyst, phosphoric acid, dibasic acid, sulfuric acid, hydrochloric acid, or the like may be used. Method may be used. Normally, the diameter of nanofibers is 10 to 1000 nm by a physical method, but cellulose nanofibers having a diameter of 3 to 10 nm, which is finer by a chemical method, can be obtained. On the other hand, the smaller the diameter and the larger the aspect ratio, the higher the physical properties such as the strength of the obtained resin composition can be expected. It may not be possible.

(1.3. Epoxy resin layer)
The epoxy resin layer is provided by covering a part or the whole of the surface of the cellulose for the purpose of imparting hydrophobicity to the cellulose.

For the composite in the present invention, an epoxy compound having one epoxy group per molecule is used because it easily reacts with both cellulose and resin during kneading to form a crosslinked structure.

The epoxy compound may have an aliphatic structure or an aromatic structure. However, in order to improve the elastic modulus and heat resistance of the obtained resin composition, it is preferable to use an epoxy compound having a molecular weight of 350 or less, and it is more preferable to use an epoxy compound having a molecular weight of 300 or less. The lower limit of the molecular weight is not particularly limited, but for example, it is preferable to use 100 or more epoxy compounds.

Further, when the composite is used in combination with a polyolefin resin such as polyethylene or polypropylene which does not have a reactive group with epoxy, an epoxy compound having an aromatic ring structure or an epoxy compound other than a glycidyl ether group is used from the viewpoint of making it more hydrophobic. It is preferable to use an epoxy compound having no ether structure.

In particular, by adopting an epoxy compound in which the aromatic ring has an aliphatic substituent, it is possible to obtain the effect of further increasing the hydrophobicity or imparting flexibility. Examples of such epoxy compounds include o-cresyl glycidyl ether (o-cresol glycidyl ether), p-tolyl glycidyl ether, m, p-cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether and the like. ..

Further, as the epoxy compound, by adopting a compound having both the groups represented by the following general formulas (1) and (2), the effect of controlling hydrophobicity and flexibility can be obtained. The embodiment is not particularly limited, and specific examples thereof include a glycidyl ether structure.

（式中、Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、任意の置換基又は水素原子を表わす。）

(In the equation, R ¹ , R ² and R ³ each independently represent an arbitrary substituent or hydrogen atom.)

As described above, it is preferable that R ¹ , R ² and R ³ in the general formula (2) independently represent an arbitrary substituent or a hydrogen atom. More specifically, R ¹ , R ² and R ³ are each independently represented by a substituent or a hydrogen atom selected from the group consisting of an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a derivative thereof. It is possible.

As an embodiment of the other epoxy compound, it is preferable that the epoxy compound has an ether structure, and the ether structure has only the ether structure represented by the above general formula (1). By adopting such a configuration, the hydrophobicity can be further enhanced.

As the compound having one epoxy group, known ones can be widely adopted. For example, an aliphatic alcohol-based epoxy compound and an epoxidized vegetable oil (general name; a double bond of a vegetable oil containing an unsaturated fatty acid can be used. Vegetable oils having an oxidized epoxy group), epoxidized rubbers (epoxidized polybutadiene, epoxidized SEBS, epoxidized natural rubbers, etc.), and aromatic phenolic epoxy compounds can be exemplified.

More specifically, examples of the aliphatic alcohol-based epoxy compound are glycidyl ethers of butanol (C4) to stearyl alcohol (C18). By adopting such a structure, the molecular weight of the epoxy compound is set to an appropriate value, and as a result, the epoxy compound volatilizes during the production of the complex while improving the elastic modulus and heat resistance of the obtained resin composition. This is suppressed, and an excellent hydrophobizing effect can be expected from the complex. Further, it may be a compound having a branch such as glycidyl ether of ethylhexanol (C8). It is more preferable that the number of carbon atoms is C4 to C18.

Examples of the epoxidized vegetable oil include epoxidized soybean oil and epoxidized flaxseed oil, and examples of the epoxidized rubber include epoxidized polybutadiene, epoxidized SEBS, epoxidized SBS, and epoxidized natural rubber.

As the aromatic phenol-based epoxy compound, aromatic phenol-based glycidyl ether is preferable, and more specifically, phenol glycidyl ether, glycidyl ether of a substitute thereof (cresol, t-butylphenol), orthophenylphenol glycidyl. Examples include ether, glycidyl ether of naphthol, and the like.

The content of the epoxy compound in the complex is preferably 2 to 100 parts by mass, more preferably 5 to 75 parts by mass, based on 100 parts by mass of the cellulose nanofibers (in terms of solid components). preferable. By adopting such a configuration, the effects of preventing aggregation and hydrophobizing can be obtained.

The thickness of the epoxy resin layer is not particularly limited, but is preferably 1 to 1000 nm, for example.

The epoxy resin layer is selected from the group consisting of an epoxy resin curing agent, an effect accelerator, an inorganic metal oxide, and a carbon material in addition to the above epoxy compound, depending on the purpose of use of the composite and the resin composition. Additives above the seed may be further included.

The composite of the present invention as described above can be obtained, for example, by dissolving an epoxy compound in an organic solvent and kneading cellulose nanofibers therein.

(2. Composition)
The composition of the present invention is preferably composed by containing the complex of the present invention in an organic solvent.

(2.1. Organic solvent)
As the organic solvent, a known organic solvent can be widely used, but the boiling point is 110 in order to prevent water from agglomerating while preventing the aggregation of cellulose when obtaining the resin composition described later. It is preferable to use an organic solvent having a temperature of ° C or higher. On the other hand, from the viewpoint of making it possible to easily remove such an organic solvent, it is preferable to use an organic solvent having a boiling point of 250 ° C. or lower.

In addition, when kneading with a hydrolyzable resin in a state containing an organic solvent, if kneading with a hydrolyzable resin is assumed for the reason of avoiding arcolisis, an organic having no hydroxyl group is expected. It is preferable to use a solvent.

More specifically, the organic solvent is a parent of both alcohols, ketones, glycols, lactones, lactams, amides, sulfoxides, ethers, etc., which have an affinity for both water and epoxy. It is preferable to use a medium organic solvent. Further, considering that the composition is kneaded with the solvent remaining, a group consisting of a ketone type, a glycol type having both ends etherified and having no hydroxyl group, a lactone type, a lactam type, an amide type, and a sulfoxide type. It is preferable to use one or more organic solvents selected from the above.

(2.2. Water)
The composition may further contain water in addition to the organic solvent to prevent the aggregation of cellulose. The water content is preferably 0.1 to 10% by mass in 100% by mass of the composition.

(3. Resin composition)
It is also preferable to prepare a resin composition containing the complex and the resin of the present invention. Such a resin composition is superior in strength and elastic modulus after curing as compared with a resin composition containing no complex.

(3.1. Resin)
As the resin to be used, polyester-based resin, polyamide-based resin, and polycarbonate-based resin because cellulose has polarity even when the composite in the present invention is formed and because it has compatibility with excess epoxy. It is preferable to use one or more selected from the group consisting of. However, since epoxy is supported on the surface of the composite and the composite has a low polarity, polystyrene such as polyethylene and polypropylene, polystyrene, ABS resin, SEBS resin, SBS resin, and AS resin are polystyrene. Resins with low polarity such as based resins may be used. Further, since it is preferable to increase the biomass ratio from the viewpoint of environmental friendliness, it is preferable to use one or more selected from the group consisting of biomass plastics and microbially produced plastics.

Rubber or thermoplastic elastomers may be used because of the high modulus of elasticity of cellulose. Examples of the rubber include diene rubber, olefin rubber, acrylic rubber, butyl rubber, epichlorohydrin rubber, silicone rubber, polysulfide rubber, fluororubber, etc., and diene rubber and olefin rubber from the viewpoint of compatibility. Is preferable. Examples of the thermoplastic elastomer include styrene-based, olefin-based, ester-based, urethane-based, amide-based, polyvinyl chloride-based, and fluorine-based, and olefin-based, ester-based, and amide-based are preferable from the viewpoint of compatibility.

More specifically, one or more selected from the group consisting of polylactic acid, polyamide 4, polyamide 11, polybutylene succinate, polyhydroxybutyrate, and a copolymer containing these structures may be used. preferable. Further, polyethylene, polypropylene, and a copolymer having the structure thereof (random polymer, block polymer) may be used.

The diene rubber is preferably styrene-butadiene rubber, isoprene rubber, butadiene rubber, chloroprene rubber, and acrylonitrile-butadiene rubber, and the olefin rubber is preferably ethylene-propylene rubber or ethylene-propylene-diene rubber.

The thermoplastic elastomer preferably has a polyethylene structure, a polypropylene structure, a butadiene structure, a polyethylene terephthalate structure, a polyamide 6 structure, a polyamide 66 structure, a polyamide 11 structure, and a polyamide 12 structure, and is a styrene-ethylene-butylene-styrene copolymer. , Styrene-butadiene-styrene copolymer, styrene-butylene-butadiene-styrene copolymer, etc. may contain a styrene structure which is another system while having an olefin structure or a diene structure.

The resin composition of the present invention is obtained by mixing (evaporating) the organic solvent and water by mixing the resin with the above-mentioned composite, which is composed of the organic solvent and the composite, and heating or the like. be able to.

(4. Method for manufacturing complex)
The method for producing a composite of the present invention is a method for producing a composite having cellulose and an epoxy-based resin layer covering a part or the whole of the surface of the cellulose, and the cellulose has one epoxy group. It is characterized by having a step 1 of adding a solution for forming an epoxy-based resin layer containing an epoxy compound and an organic solvent.

As the cellulose, the epoxy compound having one epoxy group, and the organic solvent, those described above can be used.

As a method of adding an epoxy resin layer forming solution containing an epoxy compound having one epoxy group and an organic solvent to cellulose, it is preferable to mix all of them. As a more specific embodiment of such a mixing operation, it may be melt-kneading or mixing via an organic solvent. Above all, by adopting melt-kneading, not only the productivity can be improved, but also the dispersibility of the complex becomes good.

Further, the epoxy resin layer forming solution further contains water, and after the step 1, there is a step 2 of removing the water in the epoxy resin layer forming solution by heating and / or depressurizing. May be.

The heating operation can be widely adopted by a known method, and is not particularly limited. Specifically, it is possible to adopt a method of heating using a static hot air dryer, a vacuum dryer, a rotary evaporator, and a mixed dryer (conical dryer, nower dryer, etc.). be. The heating temperature condition is preferably set to 40 to 200 ° C, more preferably 60 to 150 ° C.

As for the depressurization operation, a known method can be widely adopted, and there is no particular limitation. Specifically, the pressure may be reduced by using a device such as an oil pump, an oilless pump, or an aspirator. The pressure condition in the depressurization operation is preferably set to 0.00001 to 0.05 MPa, more preferably 0.00001 to 0.03 MPa.

Although the embodiments of the present invention have been described above, the present invention is not limited to these examples, and it is needless to say that the present invention can be implemented in various forms without departing from the gist of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

(Example 1)
1800 g of diethylene glycol dimethyl ether and 15 g of stearyl alcohol glycidyl ether (cellulose nanofiber 100) are added to 30 g of cellulose nanofibers (150 g of water-wet body having a solid content of 20% by mass) containing 50% or more of fibers having a diameter of 100 nm or less defibrated by the grinder method. 50 parts by mass of the epoxy compound) was added to the mass part, and after stirring, the pressure was reduced at 80 ° C. to obtain a wet composite of 150 g. Then, 150 g of the complex and 255 g of polylactic acid (TE-2000 manufactured by Unitika) were melt-kneaded at 190 ° C. using a twin-screw extruder (15 mmφ, L / D = 30 manufactured by Technobel) to obtain 250 g of a resin composition. rice field. The obtained resin composition was dried at 80 ° C. for 24 hours, and then used by an injection molding machine (Emerging Servic, C, MOBILE-0813) to have a length of 75 mm × a parallel portion width of 5 mm × a parallel portion length of 35. It was formed into a dumbbell test piece of mm × thickness of 2 mm.

(Example 2)
A test piece was obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of o-phenylphenol glycidyl ether.

(Example 3)
A test piece was obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of ethylhexyl alcohol glycidyl ether.

(Example 4)
A test piece was obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of ethylcaproic acid glycidyl ester.

(Example 5)
Test pieces were obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of o-cresol glycidyl ether.

(Example 6)
A test piece was obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of 4-t-butylphenol glycidyl ether.

(Example 7)
Test pieces were obtained in the same manner as in Example 1 except that 15 g of stearyl alcohol glycidyl ether was changed to 15 g of 1,2-epoxytetradecane.

(Example 8)
1800 g of cyclohexanone and 15 g of o-cresol glycidyl ether (cellulose nanofiber 100) in 30 g of cellulose nanofibers (150 g of water-wet body having a solid content of 20% by mass) containing 50% or more of fibers having a diameter of 100 nm or less defibrated by the grinder method. 50 parts by mass of the epoxy compound) was added to the mass part, and after stirring, the pressure was reduced at 80 ° C. to obtain a wet composite of 150 g. Then, 150 g of the complex and 255 g of polypropylene (Japan Polypropylene: Novatec BC06C) were melt-kneaded at 220 ° C. using a twin-screw extruder (Technobel 15 mmφ, L / D = 30) to obtain 250 g of a resin composition. .. The obtained resin composition was dried at 80 ° C. for 24 hours, and then used by an injection molding machine (Emerging Servic, C, MOBILE-0813) to have a length of 75 mm × a parallel portion width of 5 mm × a parallel portion length of 35. It was formed into a dumbbell test piece of mm × thickness of 2 mm.

(Example 9)
Test pieces were obtained in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to 15 g of 1,2-epoxytetradecane.

(Example 10)
Test pieces were obtained in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to 15 g of ethylhexyl alcohol glycidyl ether.

(Example 11)
Test pieces were obtained in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to 15 g of ethylcaproic acid glycidyl ester.

(Example 12)
A test piece was obtained in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to 15 g of o-phenylphenol glycidyl ether.

(Comparative Example 1)
200 g of polylactic acid (TE-2000 manufactured by Unitika Ltd.) was melt-kneaded using a twin-screw extruder, dried at 80 ° C. for 24 hours, and then molded into a dumbbell test piece using an injection molding machine.

(Comparative Example 2)
After adding 1800 g of diethylene glycol dimethyl ether to 30 g of cellulose nanofibers (Selish KY-110N manufactured by Daicel FineChem, 200 g of water-wet body having a solid content of 15% by weight) containing 50% or more of finely divided fibers having a diameter of 50 nm or less, and then stirring. , 150 g of a wet body wetted with a solvent was obtained by reducing the pressure at 80 ° C. (the wet body does not have an epoxy resin layer formed). A wet body containing 30 g of the cellulose nanofibers and 270 g of polylactic acid (TE-2000 manufactured by Unitika Ltd.) were kneaded at 190 ° C. to obtain 250 g of a resin composition. The obtained resin composition was dried at 80 ° C. for 24 hours, and then used by an injection molding machine (Emerging Servic, C, MOBILE-0813) to have a length of 75 mm × a parallel portion width of 5 mm × a parallel portion length of 35. It was formed into a dumbbell test piece of mm × thickness of 2 mm.

(Comparative Example 3)
200 g of polypropylene (Japan Polypropylene: Novatec BC06C) was melt-kneaded using a twin-screw extruder, dried at 80 ° C. for 24 hours, and then molded into a dumbbell test piece using an injection molding machine.

(Comparative Example 4)
1800 g of cyclohexanone is added to 30 g of cellulose nanofibers (150 g of a water-wet body having a solid content of 20% by mass) containing 50% or more of fibers having a diameter of 100 nm or less defibrated by the grinder method, and after stirring, the pressure is reduced at 80 ° C. Wet to obtain 150 g of the complex. The obtained composite 150 g and polypropylene (Japan Polypropylene: Novatec BC06C) 270 g were melt-kneaded at 220 ° C. using a twin-screw extruder (Technobel 15 mmφ, L / D = 30) to obtain 250 g of a resin composition. Obtained. The obtained resin composition was dried at 80 ° C. for 24 hours, and then used by an injection molding machine (Emerging Servic, C, MOBILE-0813) to have a length of 75 mm × a parallel portion width of 5 mm × a parallel portion length of 35. It was formed into a dumbbell test piece of mm × thickness of 2 mm.

(Comparative Example 5)
Test pieces were obtained in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to 15 g of tannic acid.

(Comparative Example 6)
A test piece was prepared in the same manner as in Example 8 except that 15 g of o-cresol glycidyl ether was changed to tirabazole D-818M: 15 g, which is a filler dispersion promoter in PP.

(Tensile strength, tensile elasticity test)
Tensile tests were performed on the test pieces of each example and comparative example at an atmospheric temperature of 23 ° C and a tensile speed of 10 mm / min n = 5 using a universal material testing machine (Instron 5567) to determine the tensile strength and tensile modulus. Calculated. The obtained results are shown in Table 1 below.

As shown in Table 1, it was confirmed that the test pieces of each example were superior in strength to the test pieces of each comparative example.

Claims (2)

A method for producing a complex having cellulose and an epoxy-based compound layer that does not chemically modify the cellulose and covers a part or the whole of the surface of the cellulose.
The step 1 comprises adding a solution for forming an epoxy compound layer containing an epoxy compound having only one epoxy group and an organic solvent to the cellulose.
A production method, wherein the structural formula of the epoxy compound has an aromatic ring. The solution for forming an epoxy-based compound layer further contains water, and the solution contains water.
The production method according to claim 1, further comprising a step 2 of removing water in the epoxy-based compound layer forming solution by heating and / or depressurizing after the step 1.