Cellulose nanofiber-dispersed thermoplastic resin reinforced material

Abstract

To provide a cellulose nanofiber-dispersed thermoplastic resin reinforced material that is lightweight and excellent in elastic modulus.SOLUTION: A cellulose nanofiber-dispersed thermoplastic resin reinforced material has a cellulose nanofiber-dispersed thermoplastic resin layer in which cellulose nanofibers and a thermoplastic resin are impregnated into a woven fabric and / or nonwoven fabric.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cellulose nanofiber-dispersed thermoplastic resin reinforced material. [Background technology]

[0002] Carbon fiber reinforced plastic (CFRP) is increasingly being used in products that require lightness and strength, from components for automobiles and aircraft to sporting goods. For example, in sporting goods, there is a demand for "lighter, stronger materials," and the use of lightweight, high-strength CFRP is progressing. However, in bats, for example, repeated hitting of the ball causes cracks to form on the surface and inside of the CFRP, so the CFRP layer is thickened to increase static strength and impact strength. In these products, if the static strength and impact strength of CFRP can be improved by 20%, it can be made thinner, resulting in a 15-30% weight reduction, which allows users to experience a significantly lighter swing feel. However, it is difficult to further improve the static strength and impact strength of CFRP in this way.

[0003] Cellulose nanofibers (CNFs) are environmentally friendly nanofibers that can be refined from wood and other materials, and are both lightweight and strong. However, controlling the dispersion of CNFs in the matrix resin is extremely difficult, and hydrophobic modification techniques and the use of organic solvents are generally considered to be the most effective methods. For this reason, it is generally considered difficult to apply CNFs to CFRP without hydrophobic treatment.

[0004] Therefore, Patent Document 1 shows that by constructing a cellulose nanofiber layer on at least one side of a carbon fiber reinforced plastic layer, that is, by constructing the carbon fiber reinforced plastic and the cellulose nanofiber as separate layers, the resulting product is lightweight and has excellent impact strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2019 / 221155 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, the material is reinforced by providing a cellulose nanofiber layer, but laminating the carbon fiber reinforced plastic and the cellulose nanofiber in separate layers is time-consuming and requires the creation of separate layers, which increases the work time and costs.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a cellulose nanofiber-dispersed thermoplastic resin reinforced material that is lightweight and has an excellent elastic modulus, simply and at low cost. [Means for solving the problem]

[0008] In light of the above-mentioned object, the inventors conducted extensive research and found that, unlike conventional methods, by impregnating cellulose nanofibers and a thermoplastic resin into a woven fabric and / or nonwoven fabric, it is possible to easily and inexpensively produce a thermoplastic resin-reinforced material in which cellulose nanofibers are dispersed, without forming carbon fiber reinforced plastic and cellulose nanofibers into separate layers, and that the material is lightweight and has a high modulus of elasticity. Based on this finding, the inventors conducted further research and completed the present invention. Specifically, the present invention encompasses the following features.

[0009] Item 1. A cellulose nanofiber-dispersed thermoplastic resin reinforced material having a cellulose nanofiber-dispersed thermoplastic resin layer in which cellulose nanofibers and thermoplastic resin are impregnated inside a woven fabric and / or nonwoven fabric.

[0010] Item 2. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to Item 1, wherein the fibers constituting the woven fabric are carbon fibers.

[0011] Item 3. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to Item 1 or 2, wherein the nonwoven fabric is a carbon nonwoven fabric.

[0012] Item 4. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to any one of Items 1 to 3, wherein the thermoplastic resin is at least one selected from the group consisting of urethane resin, polyolefin resin, polyester resin, polyamide resin, polystyrene resin, vinyl resin, polyvinyl alcohol resin, polycarbonate resin, polyacetal resin, ethylene-vinyl acetate copolymer resin, and acrylonitrile-butadiene-styrene copolymer resin.

[0013] Item 5. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to any one of Items 1 to 4, further comprising a carbon fiber reinforced plastic layer on at least one side of the cellulose nanofiber-dispersed thermoplastic resin layer.

[0014] Item 6. A method for producing a cellulose nanofiber-dispersed thermoplastic resin reinforced material according to any one of items 1 to 5, (1A) immersing the woven fabric and / or nonwoven fabric in a dispersion of the cellulose nanofibers and the thermoplastic resin; or (1B) A step of immersing the woven fabric and / or nonwoven fabric in the dispersion of the cellulose nanofibers and then impregnating the woven fabric and / or nonwoven fabric with the emulsion of the thermoplastic resin. A manufacturing method comprising:

[0015] Item 7. The manufacturing method according to Item 6, wherein a roller treatment is performed during the immersion in the dispersion liquid in step (1A) or the immersion in the emulsion in step (1B).

[0016] Item 8. The manufacturing method according to Item 6 or 7, wherein in step (1A) or (1B), the amount of cellulose nanofibers added is 0.1 to 100 parts by mass per 100 parts by mass of the woven fabric and / or nonwoven fabric.

[0017] Item 9. The manufacturing method according to any one of Items 6 to 8, wherein in the step (1A) or (1B), the amount of the thermoplastic resin added is 50 to 900 parts by mass per 100 parts by mass of the woven fabric and / or nonwoven fabric.

[0018] Item 10. After the step (1A) or (1B), (2) A step of heating the cellulose nanofiber-dispersed thermoplastic resin reinforced material obtained in step (1) to remove moisture. Item 10. The manufacturing method according to any one of items 6 to 9, comprising:

[0019] Item 11. After the step (2), (3) A step of heating and molding the obtained cellulose nanofiber-dispersed thermoplastic resin reinforced material under pressure. Item 11. The manufacturing method according to Item 10, comprising:

[0020] Item 12. The manufacturing method according to Item 11, wherein the molding pressure in step (3) is 5 MPa or more. [Effects of the Invention]

[0021] According to the present invention, a cellulose nanofiber-dispersed thermoplastic resin reinforced material can be provided that is lightweight, has excellent elastic modulus, and can be easily produced at low cost without the need for hydrophobic treatment. DETAILED DESCRIPTION OF THE INVENTION

[0022] In this specification, the term "containing" is a concept that encompasses all of "comprise," "consist essentially of," and "consist only of."

[0023] In addition, in this specification, when a numerical range is expressed as "A to B," it means A or more and B or less.

[0024] 1. Cellulose nanofiber-dispersed thermoplastic resin reinforced material The cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention has a cellulose nanofiber-dispersed thermoplastic resin layer in which cellulose nanofibers and thermoplastic resin are impregnated inside a woven fabric and / or nonwoven fabric.

[0025] According to this configuration, the presence of the thermoplastic resin allows the cellulose nanofibers to efficiently impregnate the interior of the woven fabric and / or nonwoven fabric, and the elastic modulus can also be improved by capillary action. It is possible to produce a thermoplastic resin-reinforced material with dispersed cellulose nanofibers, which is lightweight and has a high elastic modulus. Conversely, this also makes it possible to reduce the amount of carbon fiber reinforced plastic that was previously required to achieve the desired elastic modulus, which can lead to resource conservation. Furthermore, because cellulose nanofibers are lighter than carbon fiber reinforced plastics, this can also lead to lighter products.

[0026] (1-1) Cellulose nanofiber-dispersed thermoplastic resin layer Woven and / or nonwoven fabrics The fibers constituting the woven fabric are not particularly limited, and a wide variety of organic fibers can be used, including inorganic fibers such as carbon fibers (PAN-based carbon fibers, pitch-based carbon fibers, carbon nanotubes, etc.), glass fibers (glass wool, glass fiber, etc.), mineral fibers (chrysotile asbestos, white asbestos, blue asbestos, brown asbestos, direct asbestos, tremolite asbestos, and lixivitic asbestos), artificial mineral fibers (rock wool, ceramic fiber, etc.), and metal fibers (stainless steel fibers, aluminum fibers, iron fibers, nickel fibers, and copper fibers, etc.); synthetic fibers (nylon fibers, polyester fibers, acrylic fibers, vinylon fibers, polyolefin fibers, polyethylene fibers, polypropylene fibers, and polyurethane fibers, etc.), recycled fibers (rayon, polynosic, cupra, lyocell, and acetate, etc.), plant fibers (cotton fibers, hemp fibers, and flax fibers, etc.), and animal fibers (wool, silk, wild silk, mohair, cashmere, camel, llama, alpaca, vicuna, angora, and spider silk, etc.). These fibers can be used alone or in combination of two or more. Among them, carbon fiber fabrics are preferred from the viewpoints of light weight, elastic modulus, etc.

[0027] The form of the fiber may be any of continuous filaments, short fibers obtained by cutting continuous filaments, milled yarns obtained by pulverizing into powder, and the like.

[0028] The thickness of the woven fabric is not particularly limited and may vary depending on the type of fiber, but may be, for example, 50 μm to 30 mm, preferably 100 μm to 10 mm, from the viewpoints of light weight, elastic modulus, etc.

[0029] The weight of the woven fabric is not particularly limited, but is, for example, 5 to 300 g / m from the viewpoint of lightness, elasticity, etc. 2 , preferably 10 to 200 g / m 2 It can be said that:

[0030] The filament diameter of the fibers constituting the weaving yarn in the woven fabric is not particularly limited, but from the viewpoint of light weight, elastic modulus, etc., it can be, for example, 5 to 20 μm, preferably 5 to 10 μm.

[0031] The weaving yarns constituting the woven fabric may be fiber bundles. From the viewpoints of light weight, elastic modulus, etc., the fiber bundles preferably consist of, for example, 500 to 8000 filaments (original yarns), and more preferably 1000 to 6000 filaments (original yarns).

[0032] The fibers may be coated with known finishing agents such as flame retardants, water absorbents, water repellents, softeners, heat storage agents, ultraviolet screening agents, antistatic agents, antibacterial agents, deodorizers, insect repellents, mosquito repellents, luminescent agents, retroreflective agents, and bundling agents.

[0033] The fibers constituting the nonwoven fabric are not particularly limited, and a wide variety of organic fibers can be used, including inorganic fibers such as carbon fibers (PAN-based carbon fibers, pitch-based carbon fibers, carbon nanotubes, etc.), glass fibers (glass wool, glass fiber, etc.), mineral fibers (chrysotile asbestos, white asbestos, blue asbestos, brown asbestos, rectiflorite asbestos, tremolite asbestos, and liquefied asbestos), artificial mineral fibers (rock wool, ceramic fiber, etc.), and metal fibers (stainless steel fibers, aluminum fibers, iron fibers, nickel fibers, and copper fibers); synthetic fibers (nylon fibers, polyester fibers, acrylic fibers, vinylon fibers, polyolefin fibers, polyethylene fibers, polypropylene fibers, and polyurethane fibers); recycled fibers (rayon, polynosic, cupra, lyocell, and acetate); plant fibers (cotton fibers, hemp fibers, and flax fibers); and animal fibers (wool, silk, wild silk, mohair, cashmere, camel, llama, alpaca, vicuna, angora, and spider silk). These fibers can be used alone or in combination of two or more. Among them, carbon nonwoven fabrics using carbon fibers are preferred from the viewpoints of light weight, elastic modulus, etc.

[0034] The form of the fiber may be any of continuous filaments, short fibers obtained by cutting continuous filaments, milled yarns obtained by pulverizing into powder, and the like.

[0035] The thickness of the nonwoven fabric is not particularly limited and may vary depending on the type of fiber, but may be, for example, 50 μm to 30 mm, preferably 100 μm to 10 mm, from the viewpoints of light weight, elastic modulus, etc.

[0036] The basis weight of the nonwoven fabric is not particularly limited, but is, for example, 10 to 500 g / m from the viewpoint of light weight, elastic modulus, etc. 2 , preferably 20 to 200 g / m 2 It can be said that:

[0037] The fibers may be coated with known finishing agents such as flame retardants, water absorbents, water repellents, softeners, heat storage agents, ultraviolet screening agents, antistatic agents, antibacterial agents, deodorizers, insect repellents, mosquito repellents, luminescent agents, retroreflective agents, and bundling agents.

[0038] Cellulose nanofiber The cellulose nanofibers are not particularly limited and can be made from a wide variety of known cellulose nanofibers. Furthermore, any of plant-derived cellulose, animal-derived cellulose, and bacterial-derived cellulose can be suitably used as the cellulose constituting the cellulose nanofibers. These may be used alone or in combination of two or more.

[0039] The plant-derived cellulose can be selected from, for example, cellulose derived from hardwoods (eucalyptus, poplar, etc.), cellulose derived from softwoods (pine, fir, cedar, cypress, etc.), cellulose derived from herbaceous plants (straw, bagasse, reed, kenaf, abaca, sisal, etc.), and seed hair fibers (cotton, etc.). The raw pulp may be mechanical pulp obtained by mechanically treating wood chips, chemical pulp obtained by chemically removing non-cellulose components from wood chips, or dissolving pulp obtained by further removing non-cellulose components and refining it.

[0040] Other celluloses that can be used include those derived from animals such as sea squirts and bacteria such as nata de coco. Furthermore, such cellulose does not necessarily have to be composed of pure cellulose components; non-cellulose components may be present in addition to the cellulose that is the main component. Of course, it may also be composed of pure cellulose components.

[0041] The main non-cellulose components associated with cellulose nanofibers are not particularly limited and can be appropriately selected depending on the application. Examples include hemicellulose and lignin.

[0042] The ratio of pure cellulose components in cellulose nanofibers can also be set appropriately depending on the application. For example, the ratio of pure cellulose components is preferably 70% by mass or more, and more preferably 80% by mass or more, based on 100% by mass of cellulose nanofibers. The upper limit of the ratio of pure cellulose components can be set to 100% by mass. In this specification, the cellulose ratio refers to the ratio of pure cellulose components in which β-glucose molecules are linearly polymerized via glycosidic bonds, relative to 100% by mass of the total mass of the cellulose nanofibers.

[0043] The degree of polymerization of the pure cellulose component contained in the cellulose nanofibers can also be set appropriately depending on the application. For example, a cellulose component with a degree of polymerization of 500 or more, particularly 600 or more, can be used. There is no particular upper limit to the degree of polymerization of the cellulose component, but it can be set to, for example, 100,000.

[0044] There are no particular restrictions on the crystallinity of the pure cellulose component contained in the cellulose nanofibers, with 60% or more being preferred, and 70% or more being more preferred. There are no particular restrictions on the upper limit of the crystallinity of cellulose, but it can be set to, for example, 99%. Examples of the crystalline structure of the cellulose component include Type I, Type II, Type III, and Type IV.

[0045] There are no particular restrictions on the size of cellulose nanofibers, and when employing the production method of the present invention described below, the diameter is preferably 3 to 500 nm and the length is preferably 100 nm or more from the viewpoints of dispersibility, light weight, elastic modulus, etc. In this specification, the diameter of cellulose nanofibers is the median diameter obtained by SEM observation of 50 or more randomly selected cellulose nanofibers.

[0046] thermoplastic resin The thermoplastic resin is not particularly limited, and examples thereof include urethane resin, polyolefin resin (polyethylene resin, polypropylene resin, etc.), polyester resin, polyamide resin, polystyrene resin, vinyl resin (polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, etc.), polyvinyl alcohol resin, polycarbonate resin, polyacetal resin, ethylene-vinyl acetate copolymer resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), etc. These thermoplastic resins can be used alone or in combination of two or more. As these thermoplastic resins, urethane resin, polyolefin resin, polyester resin, polyamide resin, etc. are preferred from the viewpoints of ease of impregnation into woven fabrics and / or nonwoven fabrics, light weight, elastic modulus, etc., and urethane resin is more preferred.

[0047] Cellulose nanofiber dispersed thermoplastic resin layer As described above, the cellulose nanofiber-dispersed thermoplastic resin layer is formed by impregnating the interior of a woven fabric and / or nonwoven fabric with cellulose nanofibers and a thermoplastic resin. Unlike conventional methods, in which the cellulose nanofiber layer is formed separately from the carbon fiber reinforced plastic layer, the cellulose nanofibers and the thermoplastic resin are impregnated into the interior of the woven fabric and / or nonwoven fabric. In other words, while conventional methods have been used to reinforce materials by providing a distinct cellulose nanofiber layer, the present invention allows the cellulose nanofiber-dispersed thermoplastic resin to penetrate the woven fabric and / or nonwoven fabric, thereby making it possible to obtain a lightweight cellulose nanofiber-dispersed thermoplastic resin-reinforced material with an excellent elastic modulus without providing a distinct cellulose nanofiber layer. This also makes it possible to eliminate the distinct interface with the CFRP layer that would otherwise occur when a distinct cellulose nanofiber layer is provided, thereby improving strength.

[0048] According to the manufacturing method described below, the cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention is produced by immersing a woven fabric and / or nonwoven fabric in a dispersion of cellulose nanofibers and the thermoplastic resin, or by immersing the woven fabric and / or nonwoven fabric in a dispersion of cellulose nanofibers and then impregnating the woven fabric and / or nonwoven fabric with an emulsion of a thermoplastic resin. Therefore, it is difficult to precisely specify the contents of various components in the cellulose nanofiber-dispersed thermoplastic resin layer. However, from the viewpoints of light weight, elastic modulus, etc., the cellulose nanofiber content is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the woven fabric and / or nonwoven fabric.

[0049] According to the manufacturing method described below, the cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention is produced by immersing a woven fabric and / or nonwoven fabric in a dispersion of cellulose nanofibers and the thermoplastic resin, or by immersing the woven fabric and / or nonwoven fabric in a dispersion of cellulose nanofibers and then impregnating the woven fabric and / or nonwoven fabric with an emulsion of a thermoplastic resin. Therefore, it is difficult to precisely specify the contents of various components in the cellulose nanofiber-dispersed thermoplastic resin layer. However, from the viewpoints of light weight, elastic modulus, etc., the content of the thermoplastic resin is preferably 50 to 900 parts by mass, more preferably 100 to 300 parts by mass, per 100 parts by mass of the woven fabric and / or nonwoven fabric.

[0050] (1-2) Carbon fiber reinforced plastic layer The cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention can be composed only of the cellulose nanofiber-dispersed thermoplastic resin layer, or it can have a carbon fiber reinforced plastic layer on at least one side of the cellulose nanofiber-dispersed thermoplastic resin layer. In the present invention, the carbon fiber reinforced plastic layer is a layer containing carbon fiber reinforced plastic.

[0051] This carbon fiber reinforced plastic can usually employ a layer in which carbon fibers are impregnated with a thermoplastic resin, that is, the carbon fibers are dispersed in a thermoplastic resin matrix.

[0052] In this case, the carbon fiber material is not particularly limited as long as it is a structure made of carbon fibers (particularly a structure made of conductive carbon fibers). Examples include a planar carbon fiber sheet, a pipe-shaped carbon fiber sheet, a wing-shaped carbon fiber sheet, an L-shaped carbon fiber sheet, and an H-shaped carbon fiber sheet. In particular, not only carbon fiber materials in which carbon fibers are arranged linearly, but also carbon fiber materials with complex three-dimensional shapes can be used. From the viewpoints of light weight, elastic modulus, etc., the fiber diameter of each carbon fiber constituting such carbon fiber material is preferably 0.001 to 50 μm on average. As such carbon fiber materials, known or commercially available products can be used.

[0053] The thermoplastic resin is not particularly limited, and examples thereof include urethane resin, polyolefin resin (polyethylene resin, polypropylene resin, etc.), polyester resin, polyamide resin, polystyrene resin, vinyl resin (polyvinyl chloride resin, polyvinyl acetate resin, polyvinylidene chloride resin, etc.), polyvinyl alcohol resin, polycarbonate resin, polyacetal resin, ethylene-vinyl acetate copolymer resin, acrylonitrile-butadiene-styrene copolymer resin (ABS resin), etc. These thermoplastic resins can be used alone or in combination of two or more. As these thermoplastic resins, from the viewpoints of light weight, elastic modulus, etc., urethane resin, polyolefin resin, polyester resin, polyamide resin, etc. are preferred, and urethane resin is more preferred.

[0054] The thickness of such a carbon fiber reinforced plastic layer is preferably 10 to 500 μm, more preferably 50 to 200 μm, from the viewpoints of light weight, elastic modulus, and the like.

[0055] Since the carbon fiber reinforced plastic layer is a layer in which carbon fibers are impregnated with a thermoplastic resin, it is difficult to strictly specify the contents of various components. However, from the viewpoints of light weight, elastic modulus, etc., the content of the thermoplastic resin is preferably 50 to 900 parts by mass, more preferably 100 to 300 parts by mass, per 100 parts by mass of carbon fibers.

[0056] (1-3) Cellulose nanofiber-dispersed thermoplastic resin reinforced material As described above, the cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention has at least a cellulose nanofiber-dispersed thermoplastic resin layer, and may also have a carbon fiber reinforced plastic layer as needed.

[0057] The configuration of such a cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention is not particularly limited as long as it has a cellulose nanofiber-dispersed thermoplastic resin layer, and it is also possible to adopt a configuration in which at least one cellulose nanofiber-dispersed thermoplastic resin layer is arranged between two carbon fiber reinforced plastic layers, or a configuration in which carbon fiber reinforced plastic layers and cellulose nanofiber-dispersed thermoplastic resin layers are arranged alternately.

[0058] The present invention provides a lightweight, cellulose nanofiber-dispersed thermoplastic resin-reinforced material with excellent elastic modulus, enabling the production of lightweight sports goods that could not be achieved with conventional technologies. Specifically, the material is expected to be put to practical use in golf clubs (whole), tennis rackets (frames, shafts, etc.), baseball and softball bats (whole), badminton rackets (frames, shafts, etc.), shoes (soles and internal plates), etc.

[0059] For example, baseball and softball bats have thick carbon fiber layers to improve durability because the surface and carbon fiber layer break when repeatedly hitting balls. However, the present invention provides a cellulose nanofiber-dispersed thermoplastic resin reinforced material with excellent elastic modulus, which makes it possible to reduce the number of carbon fiber layers and reduce weight.

[0060] Furthermore, although the frame and shaft of a badminton racket do not break simply by hitting a shuttlecock, accidental hitting of objects other than the shuttlecock is common, making it necessary to ensure a sufficient elastic modulus for the product. High-elasticity carbon fibers are sometimes used to reduce the shaft weight, but in such cases the elastic modulus tends to be low, so the carbon fiber layers are thickened to increase durability. According to the present invention, a cellulose nanofiber-dispersed thermoplastic resin-reinforced material with an excellent elastic modulus can be obtained, making it possible to reduce the number of carbon fiber layers and reduce weight.

[0061] Carbon fiber reinforced plastic materials, which have been popular in the sports market, have often been used in aerospace and industrial applications. Therefore, in addition to the expansion of applications to sporting goods such as those mentioned above, they can also be used in automobile bodies and parts, aircraft bodies and parts, and ETC gate bars on highways, which are all becoming increasingly lightweight.

[0062] Furthermore, in Japan, where the aging society is accelerating, maintaining the health of the elderly is a major issue. Elderly people gradually experience a decline in physical strength and muscle power, making it increasingly difficult to move around. The use of the cellulose nanofiber-dispersed thermoplastic resin-reinforced material of the present invention will enable the development of lightweight, durable clothing, shoes, and braces that support the walking of the elderly, making these products useful for elderly people.

[0063] 2. Manufacturing method for cellulose nanofiber-dispersed thermoplastic resin reinforced material The method for producing the cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention is not particularly limited, but may be (1A) immersing the woven fabric and / or nonwoven fabric in a dispersion of the cellulose nanofibers and the thermoplastic resin; or (1B) A step of immersing the woven fabric and / or nonwoven fabric in the dispersion of the cellulose nanofibers and then impregnating the woven fabric and / or nonwoven fabric with the emulsion of the thermoplastic resin. Equipped with.

[0064] By adopting such a method, the presence of the thermoplastic resin allows the cellulose nanofibers to efficiently penetrate into the interior of the woven fabric and / or nonwoven fabric, even without subjecting the cellulose nanofibers to hydrophobic treatment in step (1A) or (1B), and also makes it possible to improve the elastic modulus through capillary action.

[0065] Furthermore, by adopting this method, it is possible to improve the modulus of elasticity by using cellulose nanofibers. This, in turn, makes it possible to reduce the amount of carbon fiber reinforced plastic that was previously required to achieve the desired modulus of elasticity, which could lead to resource conservation. Furthermore, because cellulose nanofibers are lighter than carbon fiber reinforced plastics, this could lead to weight reductions in products, and in the case of mobile objects (automobiles, aircraft, etc.), this could also lead to improved fuel efficiency.

[0066] (2-1) Process (1A) The cellulose nanofibers, thermoplastic resin, and woven and / or nonwoven fabrics described above in "(1-1) Cellulose nanofiber-dispersed thermoplastic resin layer" can be used. The same applies to preferred embodiments. Microgel can also be used as the thermoplastic resin.

[0067] The dispersion of cellulose nanofibers and thermoplastic resin further contains a solvent (such as alcohols, for example, monoalcohols such as methanol, ethanol, propanol, isopropanol, and butanol, Examples of polyhydric alcohols include ethylenediols such as ethylene glycol, diethylene glycol, thiodiethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; propanediols such as 2-methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, and 3-methoxy-1,2-propanediol; butanediols such as 2-butene-1,4-diol, 1,3-butanediol, and 2-methyl-1,4-butanediol; 2-methyl-2,4-pentanediol, 1,5-pentanediol, 1,4-pentanediol, and 3-methyl-1,3-pentanediol; pentanediols such as 1,2-hexanediol, 2,4-diethyl-1,5-pentanediol, etc.; hexanediols such as 1,2-hexanediol, etc.; heptanediols such as 1,2,6-trimethyl-1,7-heptanediol, 2,4,6-triethyl-1,7-heptanediol, etc.; octanediols such as 3,6-dithia-1,8-octanediol, etc.; alkylene diols such as propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, etc.; polyols such as glycerin, hexanetriol, thiodiglycol, trimethylolpropane, etc.; acetylene alcohol, etc. Examples of glycol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monopropyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and ethylene glycol monophenyl ether. Examples of amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, and tetramethylpropylenediamine; Other polar solvents include, for example, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 3-methylsulfolane, 3-sulfolene, bis(2-hydroxyethyl)sulfone, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone-5-carboxylic acid, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone, diacetone alcohol, 4-picoline, etc.), as well as pigments (carbon, titanium oxide, lead silicate, aluminum phosphate, bismuth hydroxide, yttrium hydroxide, aluminum silicate, talc, etc.), functional agents (microgel, etc.), acids (acetic acid, lactic acid, formic acid, propionic acid, sulfamic acid, etc.), etc.

[0068] In this way, by immersing a woven fabric and / or a nonwoven fabric in a dispersion of cellulose nanofibers and a thermoplastic resin, the cellulose nanofibers and the thermoplastic resin can be impregnated into the interior of the woven fabric and / or nonwoven fabric.

[0069] The amounts (charge amounts) of each component used are not particularly limited, but can be adjusted so that the amounts (charge amounts) of cellulose nanofibers and thermoplastic resin used fall within the above-mentioned content ranges. However, according to the production method of the present invention, it is possible to assume that when a woven fabric and / or nonwoven fabric is immersed in a dispersion of cellulose nanofibers and thermoplastic resin, only a portion of the cellulose nanofibers and thermoplastic resin penetrates the interior of the woven fabric and / or nonwoven fabric. Therefore, the amount (charge amount) of cellulose nanofibers used is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of woven fabric and / or nonwoven fabric. The amount (charge amount) of thermoplastic resin used is preferably 50 to 900 parts by mass, more preferably 100 to 300 parts by mass, per 100 parts by mass of woven fabric and / or nonwoven fabric.

[0070] In the production method of the present invention, in the dispersion of cellulose nanofibers and thermoplastic resin, the thermoplastic resin (particularly the microgel of the thermoplastic resin) penetrates into the network structure (mesh-like) of the cellulose nanofibers, and together with the action of the polymer functional groups, it is believed to be uniformly dispersed. When a woven fabric and / or nonwoven fabric is immersed in the dispersion in this state, the cellulose nanofibers, together with the thermoplastic resin that has penetrated into the network structure, can be impregnated into the interior of the woven fabric and / or nonwoven fabric.

[0071] In the manufacturing method of the present invention, the temperature at which the woven fabric and / or nonwoven fabric is immersed in the dispersion of cellulose nanofibers and thermoplastic resin is not limited, but from the viewpoint of easily impregnating the cellulose nanofibers and thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric, a temperature of 10 to 90°C is preferred, and 20 to 70°C is more preferred.

[0072] In the manufacturing method of the present invention, the time for immersing the woven fabric and / or nonwoven fabric in the dispersion of cellulose nanofibers and thermoplastic resin is not limited, but from the viewpoint of easily impregnating the cellulose nanofibers and thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric, 0.5 to 48 hours is preferred, and 2 to 6 hours is more preferred.

[0073] As described above, after step (1A), a roller treatment can be performed. By performing the roller treatment, the gaps between the cellulose nanofibers and the thermoplastic resin can be reduced, which makes it easier to further impregnate the cellulose nanofibers and the thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric.

[0074] The roller treatment is not particularly limited, but can be carried out according to a conventional method.

[0075] In the method of the present invention for producing a cellulose nanofiber-dispersed thermoplastic resin-reinforced material, the above step (1A) can be repeated multiple times (particularly 2 to 3 times), which makes it easier to further impregnate the cellulose nanofibers and thermoplastic resin into the woven fabric and / or nonwoven fabric.

[0076] (2-2) Process (1B) The cellulose nanofibers, thermoplastic resin, and woven and / or nonwoven fabrics described above in "(1-1) Cellulose nanofiber-dispersed thermoplastic resin layer" can be used. The same applies to preferred embodiments. Microgel can also be used as the thermoplastic resin.

[0077] The cellulose nanofiber dispersion liquid further contains a solvent (such as alcohols, for example, monoalcohols such as methanol, ethanol, propanol, isopropanol, and butanol, Examples of polyhydric alcohols include ethylenediols such as ethylene glycol, diethylene glycol, thiodiethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; propanediols such as 2-methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, and 3-methoxy-1,2-propanediol; butanediols such as 2-butene-1,4-diol, 1,3-butanediol, and 2-methyl-1,4-butanediol; 2-methyl-2,4-pentanediol, 1,5-pentanediol, 1,4-pentanediol, and 3-methyl-1,3-pentanediol; pentanediols such as 1,2-hexanediol, 2,4-diethyl-1,5-pentanediol, etc.; hexanediols such as 1,2-hexanediol, etc.; heptanediols such as 1,2,6-trimethyl-1,7-heptanediol, 2,4,6-triethyl-1,7-heptanediol, etc.; octanediols such as 3,6-dithia-1,8-octanediol, etc.; alkylene diols such as propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, etc.; polyols such as glycerin, hexanetriol, thiodiglycol, trimethylolpropane, etc.; acetylene alcohol, etc. Examples of glycol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monopropyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and ethylene glycol monophenyl ether. Examples of amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, and tetramethylpropylenediamine; Other polar solvents include, for example, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 3-methylsulfolane, 3-sulfolene, bis(2-hydroxyethyl)sulfone, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone-5-carboxylic acid, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone, diacetone alcohol, 4-picoline, etc.), as well as pigments (carbon, titanium oxide, lead silicate, aluminum phosphate, bismuth hydroxide, yttrium hydroxide, aluminum silicate, talc, etc.), functional agents (microgel, etc.), acids (acetic acid, lactic acid, formic acid, propionic acid, sulfamic acid, etc.), etc.

[0078] The thermoplastic resin emulsion further contains a solvent (such as alcohols, for example, monoalcohols such as methanol, ethanol, propanol, isopropanol, and butanol, Examples of polyhydric alcohols include ethylenediols such as ethylene glycol, diethylene glycol, thiodiethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; propanediols such as 2-methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, and 3-methoxy-1,2-propanediol; butanediols such as 2-butene-1,4-diol, 1,3-butanediol, and 2-methyl-1,4-butanediol; 2-methyl-2,4-pentanediol, 1,5-pentanediol, 1,4-pentanediol, and 3-methyl-1,3-pentanediol; pentanediols such as 1,2-hexanediol, 2,4-diethyl-1,5-pentanediol, etc.; hexanediols such as 1,2-hexanediol, etc.; heptanediols such as 1,2,6-trimethyl-1,7-heptanediol, 2,4,6-triethyl-1,7-heptanediol, etc.; octanediols such as 3,6-dithia-1,8-octanediol, etc.; alkylene diols such as propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, etc.; polyols such as glycerin, hexanetriol, thiodiglycol, trimethylolpropane, etc.; acetylene alcohol, etc. Examples of glycol derivatives include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, polyethylene glycol monomethyl ether, ethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethylene glycol monoisobutyl ether, propylene glycol monopropyl ether, ethylene glycol diacetate, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and ethylene glycol monophenyl ether. Examples of amines include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, and tetramethylpropylenediamine; Other polar solvents include, for example, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, sulfolane, 3-methylsulfolane, 3-sulfolene, bis(2-hydroxyethyl)sulfone, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, 2-pyrrolidone-5-carboxylic acid, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, acetonitrile, acetone, diacetone alcohol, 4-picoline, etc.), as well as pigments (carbon, titanium oxide, lead silicate, aluminum phosphate, bismuth hydroxide, yttrium hydroxide, aluminum silicate, talc, etc.), functional agents (microgel, etc.), acids (acetic acid, lactic acid, formic acid, propionic acid, sulfamic acid, etc.), etc.

[0079] In this way, by immersing a woven fabric and / or nonwoven fabric in a dispersion of cellulose nanofibers and then immersing the woven fabric and / or nonwoven fabric after immersion in the dispersion of cellulose nanofibers in an emulsion of a thermoplastic resin, the interior of the woven fabric and / or nonwoven fabric can be impregnated with the cellulose nanofibers and the thermoplastic resin.

[0080] The amounts (charge amounts) of each component used are not particularly limited, but can be adjusted so that the amounts (charge amounts) of cellulose nanofibers and thermoplastic resin used fall within the above-mentioned content ranges. However, according to the production method of the present invention, the amounts (charge amounts) of cellulose nanofibers and thermoplastic resin used can be greater than the above-mentioned contents, taking into account cases where, when a woven fabric and / or nonwoven fabric is immersed in a cellulose nanofiber dispersion, only a portion of the cellulose nanofibers penetrates into the interior of the woven fabric and / or nonwoven fabric, or when a woven fabric and / or nonwoven fabric after immersion in a cellulose nanofiber dispersion is immersed in a thermoplastic resin emulsion, only a portion of the thermoplastic resin penetrates into the interior of the woven fabric and / or nonwoven fabric. For this reason, the amount (charge amount) of cellulose nanofibers used is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the woven fabric and / or nonwoven fabric. The amount of thermoplastic resin used (charged amount) is preferably 50 to 900 parts by mass, more preferably 100 to 300 parts by mass, per 100 parts by mass of woven fabric and / or nonwoven fabric.

[0081] In the manufacturing method of the present invention, woven fabrics and / or nonwoven fabrics are immersed in a dispersion of cellulose nanofibers, and then the woven fabrics and / or nonwoven fabrics that have been immersed in the dispersion of cellulose nanofibers are immersed in an emulsion of thermoplastic resin.The thermoplastic resin (particularly a microgel of the thermoplastic resin) penetrates into the network structure (i.e., mesh-like) of the cellulose nanofibers, and, together with the action of the polymer functional groups, is uniformly dispersed, and the cellulose nanofibers can be impregnated into the interior of the woven fabrics and / or nonwoven fabrics, along with the thermoplastic resin that has penetrated into the network structure.

[0082] In the manufacturing method of the present invention, the temperature at which the woven fabric and / or nonwoven fabric is immersed in the dispersion of cellulose nanofibers and the emulsion of thermoplastic resin is not limited, but from the viewpoint of easily impregnating the cellulose nanofibers and thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric, a temperature of 10 to 90°C is preferred, and 20 to 70°C is more preferred.

[0083] In the manufacturing method of the present invention, the time for which the woven fabric and / or nonwoven fabric is immersed in the dispersion of cellulose nanofibers and the emulsion of thermoplastic resin is not limited, but from the viewpoint of easily impregnating the cellulose nanofibers and thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric, 0.5 to 48 hours is preferred, and 2 to 6 hours is more preferred.

[0084] As described above, after step (1A), a roller treatment can be performed. By performing the roller treatment, the gaps between the cellulose nanofibers and the thermoplastic resin can be reduced, which makes it easier to further impregnate the cellulose nanofibers and the thermoplastic resin into the interior of the woven fabric and / or nonwoven fabric.

[0085] The roller treatment is not particularly limited, but can be carried out according to a conventional method.

[0086] In the method of the present invention for producing a cellulose nanofiber-dispersed thermoplastic resin-reinforced material, the above step (1A) can be repeated multiple times (particularly 2 to 3 times), which makes it easier to further impregnate the cellulose nanofibers and thermoplastic resin into the woven fabric and / or nonwoven fabric.

[0087] (2-3) Process (2) In the method for producing a cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention, after the above step (1A) or (1B), (2) A step of heating the cellulose nanofiber-dispersed thermoplastic resin reinforced material obtained in step (1) to remove moisture. It can also be equipped with.

[0088] This makes it possible to remove excess water present in the cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention.

[0089] In the manufacturing method of the present invention, the temperature at which the cellulose nanofiber-dispersed thermoplastic resin reinforced material is heated to remove moisture is not limited, but from the viewpoints of light weight, elastic modulus, etc., a temperature of 10 to 90°C is preferred, and 20 to 70°C is more preferred.

[0090] In the manufacturing method of the present invention, the time required to heat the cellulose nanofiber-dispersed thermoplastic resin reinforced material to remove moisture is not limited, but from the standpoints of light weight, elastic modulus, etc., 0.5 to 48 hours is preferred, and 2 to 6 hours is more preferred.

[0091] (2-4) Process (3) In the method for producing a cellulose nanofiber-dispersed thermoplastic resin reinforced material of the present invention, after the above step (2), (3) A step of heating and molding the obtained cellulose nanofiber-dispersed thermoplastic resin reinforced material under pressure. It can also be equipped with.

[0092] By performing pressure molding, the gaps between the cellulose nanofibers and the thermoplastic resin can be further reduced.

[0093] In the manufacturing method of the present invention, the temperature at which the cellulose nanofiber-dispersed thermoplastic resin reinforced material is heated and molded is not limited, but from the viewpoints of light weight, elastic modulus, etc., a temperature of 10 to 90°C is preferred, and 20 to 70°C is more preferred.

[0094] In the manufacturing method of the present invention, the temperature at which the cellulose nanofiber-dispersed thermoplastic resin reinforced material is heated and molded is not limited, but from the viewpoints of light weight, elastic modulus, etc., 0.5 to 48 hours is preferred, and 2 to 6 hours is more preferred.

[0095] In the manufacturing method of the present invention, the pressure when heating and molding the cellulose nanofiber-dispersed thermoplastic resin reinforced material is not limited, but from the viewpoints of light weight, elastic modulus, etc., it is preferably 5 MPa or more, more preferably 10 to 60 MPa, and even more preferably 20 to 30 MPa. [Example]

[0096] The present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[0097] In the following examples and comparative examples, the thermoplastic resin used was Superflex 130 (a thermoplastic urethane resin manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), which is an aqueous thermoplastic resin emulsion.

[0098] In the following examples and comparative examples, Rheocrysta I-2SX (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.; average fiber diameter 4 nm, average aspect ratio 280) was used as the cellulose nanofiber.

[0099] [Example 1] Place a sheet of carbon fiber nonwoven fabric (200g / m²) of approximately the same size on a tray covered with a Teflon sheet. 2 A mixture of 100 g of Superflex 130 (solid content: 35%), a thermoplastic resin emulsion, and 100 g of Leocrysta I-2SX (cellulose nanofiber content: 0.5%), a cellulose nanofiber dispersion, was placed on the carbon fiber nonwoven fabric, and the fabric was allowed to stand for 30 minutes.

[0100] Next, the carbon fiber nonwoven fabric was left in the tray in a thermostatic chamber at 70°C for 4 to 6 hours to remove the moisture. In practice, the moisture is removed in about 2 hours.

[0101] The mixture was then heated at 220°C and 24 MPa for 10 minutes and cooled under pressure in a cooling press to form a test piece with a thickness of 1.0 mm. The density of the cellulose nanofiber in the obtained test piece was 1.6 g / cm. 3, the density of thermoplastic resin is 1.0 g / cm 3 , the density of carbon fiber is 1.8g / cm 3 It was.

[0102] [Example 2] Place a sheet of carbon fiber nonwoven fabric (200g / m²) of approximately the same size on a tray covered with a Teflon sheet. 2 A mixture of 100 g of Superflex SF130 (solid content: 35%), a thermoplastic resin emulsion, and 100 g of Rheocrysta I-2SX (cellulose nanofiber content: 0.5%), a cellulose nanofiber dispersion, was placed on the carbon fiber nonwoven fabric, and the fabric was impregnated with the mixture. The fabric was then rolled for 2 minutes with a Teflon (registered trademark) roller and allowed to stand for 1 minute. The carbon fiber nonwoven fabric was then turned over and the same procedure was repeated again, after which the fabric was left to stand for 30 minutes.

[0103] Next, the carbon fiber nonwoven fabric was left in the tray in a thermostatic chamber at 70°C for 4 to 6 hours to remove the moisture. In practice, the moisture is removed in about 2 hours.

[0104] The mixture was then heated at 220°C and 24 MPa for 10 minutes and cooled under pressure in a cooling press to form a test piece with a thickness of 1.0 mm. The density of the cellulose nanofiber in the obtained test piece was 1.6 g / cm. 3 , the density of thermoplastic resin is 1.0 g / cm 3 , the density of carbon fiber is 1.8g / cm 3 It was.

[0105] [Example 3] Place a sheet of carbon fiber nonwoven fabric (200g / m²) of approximately the same size on a tray covered with a Teflon sheet. 2A mixture of 100 g of Superflex 130 (solid content: 35%), a thermoplastic resin emulsion, and 100 g of Rheocrysta I-2SX (cellulose nanofiber content: 0.5%), a cellulose nanofiber dispersion, was placed on the carbon fiber nonwoven fabric, and the fabric was impregnated with the mixture. The fabric was then rolled for 2 minutes with a Teflon (registered trademark) roller and allowed to stand for 1 minute. The carbon fiber nonwoven fabric was then turned over and the same procedure was repeated again, after which the fabric was left to stand for 30 minutes.

[0106] Next, the carbon fiber nonwoven fabric was left in the tray in a thermostatic chamber at 70°C for 4 to 6 hours to remove the moisture. In practice, the moisture is removed in about 2 hours.

[0107] The mixture was then heated at 220°C and 24 MPa for 5 minutes and cooled under pressure in a cooling press to form a test piece with a thickness of 1.0 mm. The density of the cellulose nanofiber in the obtained test piece was 1.6 g / cm. 3 , the density of thermoplastic resin is 1.0 g / cm 3 , the density of carbon fiber is 1.8g / cm 3 It was.

[0108] [Comparative Example 1] A test piece for Comparative Example 1 was obtained by carrying out the same operation as in Example 1, except that cellulose nanofibers were not used.

[0109] Comparative Example 2 A test piece for Comparative Example 2 was obtained by carrying out the same operation as in Example 2, except that cellulose nanofibers were not used.

[0110] Comparative Example 3 A test piece for Comparative Example 3 was obtained by carrying out the same operation as in Example 3, except that cellulose nanofibers were not used.

[0111] Elasticity Modulus The bending test specimens were cut into 15 x 100 mm pieces, and three pieces were prepared for each example. The three-point bending test was performed using a universal testing machine (59R5582, manufactured by Instron Japan Co., Ltd.) with a span of 40 mm and a constant loading rate of 2.5 mm / min. Data on the load-deflection relationship was obtained, and the elastic modulus was calculated from the slope of the linear portion.

[0112] As a result, the test piece of Example 3 had an elastic modulus of 28.4 GPa, and the test piece of Comparative Example 3 had an elastic modulus of 22.7 GPa.

Claims

1. A cellulose nanofiber-dispersed thermoplastic resin reinforced material having a cellulose nanofiber-dispersed thermoplastic resin layer impregnated with cellulose nanofibers and a thermoplastic resin inside a woven fabric and / or nonwoven fabric, wherein the thermoplastic resin is a urethane resin.

2. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to claim 1, wherein the fibers constituting the woven fabric are carbon fibers.

3. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to claim 1 , wherein the nonwoven fabric is a carbon nonwoven fabric.

4. The cellulose nanofiber-dispersed thermoplastic resin reinforced material according to claim 1 , further comprising a carbon fiber reinforced plastic layer on at least one side of the cellulose nanofiber-dispersed thermoplastic resin layer.

5. A method for producing a cellulose nanofiber-dispersed thermoplastic resin reinforced material according to any one of claims 1 to 4, (1A) a step of immersing the woven fabric and / or nonwoven fabric in a dispersion of the cellulose nanofibers and the thermoplastic resin; or (1B) A step of immersing the woven fabric and / or nonwoven fabric in the dispersion of the cellulose nanofibers and then impregnating the nonwoven fabric with the emulsion of the thermoplastic resin. wherein the thermoplastic resin is a urethane resin.

6. The method according to claim 5 , wherein a roller treatment is performed during the immersion in the dispersion in the step (1A) or the immersion in the emulsion in the step (1B).

7. The manufacturing method according to claim 5, wherein in step (1A) or (1B), the amount of the cellulose nanofibers added is 0.1 to 100 parts by mass per 100 parts by mass of the woven fabric and / or nonwoven fabric.

8. The method according to claim 5, wherein in the step (1A) or (1B), the amount of the thermoplastic resin added is 5 to 90 parts by mass per 100 parts by mass of the woven fabric and / or nonwoven fabric.

9. After the step (1A) or (1B), (2) A step of heating the cellulose nanofiber-dispersed thermoplastic resin reinforced material obtained in step (1) to remove moisture. The method of claim 5 , comprising:

10. After the step (2), (3) A step of heating and molding the obtained cellulose nanofiber-dispersed thermoplastic resin reinforced material under pressure. The method of claim 9 , comprising:

11. The method according to claim 10, wherein the molding pressure in the step (3) is 5 MPa or more.