Fibrous molded body, fibrous binder, and use thereof

Abstract

An object of the present invention is to provide a fiber molded body having sufficient strength and a composite material using the same. Another problem addressed by the present invention is to provide: a fiber molded body that uses carbon fibers and has sufficient strength; and a composite material that uses the fiber molded body. A fibrillated fibrous binder is used to produce a fiber molded article that is processed into a non-woven fabric or the like. One embodiment of the fiber molded body includes a main fiber material and a fibrous binder, the content ratio of the main fiber material and the fibrous binder being 1-20 parts by weight of the fibrous binder with respect to 100 parts by weight of the main fiber material, and the Crill ratio of the fibrous binder being 1.25-3.00.

Description

Technical Field

[0001] The present invention relates to a fiber molded body, a fibrous binder used therefor, and applications thereof. Background Art

[0002] Fiber reinforced plastics (FRP: Fiber Reinforced Plastics) are reinforced plastic materials that use epoxy resin, phenolic resin, etc. as a base material (matrix) and are compounded with fiber materials such as glass fiber and carbon fiber to improve various functions. Among them, carbon fiber is a lightweight material with excellent strength and elastic modulus. Carbon fiber reinforced plastics (CFRP: Carbon Fiber Reinforced Plastics) using carbon fiber are used in a wide range of fields such as automobile components, ship components, aircraft components, spacecraft components, drone components, civil engineering materials, sports equipment, components for electronic equipment and electrical products such as personal computers.

[0003] Generally speaking, FRP is produced by impregnating a sheet-shaped fiber material with a resin component as a matrix. The technical development for improving the performance of FRP involves many aspects, but as one of the important factors in the production of composite materials using such fiber materials, it is expected that the fiber molding itself has sufficient strength before the matrix is ​​impregnated.

[0004] As a sheet-like fiber material used in FRP, a representative material is a nonwoven fabric. The method of making a nonwoven fabric from a fiber material is not limited to the field of FRP, and various methods have been developed. In addition, research and development are also being conducted on the production of a nonwoven fabric that is used for the above-mentioned FRP.

[0005] For example, in a fiber-reinforced plastic molded body using a thermoplastic resin as a binder for carbon fibers, if the thermoplastic resin melts at high temperatures such as hot melting, the fixation of the interlacing points of the carbon fibers is damaged, resulting in the collapse of the three-dimensional structure of the carbon fibers, the carbon fibers becoming easily oriented in a specific direction, and the strength being reduced. In order to solve such a problem, a method of using a mixed dispersion of carbon fibers and water-swellable fibrillated fibers for a papermaking process is disclosed for a papermaking sheet before resin impregnation (e.g., Patent Document 1).

[0006] In addition, when inorganic fibers such as carbon fibers, glass fibers, and metal fibers are processed into nonwoven fabrics by a wet papermaking method, the inorganic fibers are hydrophobic and thus have poor dispersibility in water. This makes it difficult to obtain inorganic fiber sheets of good quality. To solve this problem, a technology using a dispersant containing a specified surfactant or resin is disclosed (for example, Patent Document 2).

[0007] Furthermore, in recent years, there has been a worldwide consensus that sustainable development should be promoted. As the use of composite materials composed of fibers such as carbon fibers and base materials has progressed, there has also been a demand for the development of their recycling, as described above.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: International Publication No. 2014 / 021366

[0011] Patent Document 2: Japanese Patent Application Publication No. 2017-57511 Summary of the invention

[0012] Problems to be solved by the invention

[0013] As described above, as a countermeasure for bringing out the excellent properties of the fibers used in FRP, it is required that the strength of the fiber molding itself before the base material is impregnated is excellent. However, if the fiber components such as carbon fibers are separated from the molded products such as CFRP for reuse, the separated regenerated carbon fibers are very different from the unused fiber state, and in many cases, they become fragmented short fibers compared to the unused fibers. Even if you want to use the regenerated carbon fibers to process them into fiber molding sheets, etc., they cannot be processed into sheets in the first place, or even if they are processed into sheets, it is difficult to obtain the strength, resistance and other properties required as materials for FRP.

[0014] Therefore, as a countermeasure for producing fiber molded body sheets using regenerated fibers, increasing the amount of binder is also considered. However, from the perspective of producing FRP with desired performance, in order to further exert the characteristics of the main fiber material, the amount of binder is required to be as small as possible. In addition, in order to use various fiber materials to produce molded bodies without being limited to carbon fibers, a suitable binder is required.

[0015] In view of the above circumstances, one of the problems to be solved is to provide a fiber molded product having sufficient strength and a composite material using the same.

[0016] Another problem to be solved is to provide a fiber molded body using recycled carbon fibers and having sufficient strength, and a composite material using the same.

[0017] Another problem to be solved is to provide a fiber molded body having sufficient strength using various fiber materials and a composite material using the same.

[0018] Means for solving problems

[0019] The inventors of the present application have conducted intensive studies and have found that a fiber molded product having a predetermined strength suitable for the production of FRP, etc., can be formed by using a fibrillated fibrous binder. The present disclosure has been completed based on the above findings.

[0020] The invention proposed by the present disclosure can be grasped in many aspects and in many ways, and as a means for solving the problem, for example, it can include the specific methods described below. It should be noted that in the present disclosure, the invention proposed in the present disclosure is referred to as "the present invention" according to the overall concept or each method.

[0021] [1] A fiber molded body, the fiber molded body comprising a main fiber material and a fibrous binder,

[0022] The content ratio of the main fiber material to the fibrous binder is 1 to 20 parts by weight of the fibrous binder relative to 100 parts by weight of the main fiber material.

[0023] The Crill ratio of the fibrous binder is 1.25 to 3.00.

[0024] [2] The fiber molded product according to [1] above, wherein the average fiber length of the fibrous binder is 0.30 to 2.50 mm.

[0025] [3] A fiber molded body as described in [1] or [2] above, wherein the main fiber material is one or more selected from the group consisting of carbon fiber, glass fiber, metal fiber, natural fiber, cellulose fiber, regenerated fiber, semi-synthetic fiber and synthetic fiber.

[0026] [4] The fiber molded body as described in [1] or [2] above, wherein the main fiber material is one or more selected from the group consisting of carbon fiber, glass fiber, PET fiber and aramid fiber.

[0027] [5] The fiber molded product according to [1] or [2] above, wherein the main fiber material is carbon fiber.

[0028] [6] The fiber molded product according to any one of [3] to [5] above, wherein the carbon fiber is first-use carbon fiber, recycled carbon fiber, or a mixed fiber thereof.

[0029] [7] The fiber molded product according to any one of [1] to [6] above, wherein the fibrous binder is fibrillated cellulose fibers.

[0030] [8] The fiber molded product according to any one of [1] to [7] above, wherein the fine fiber ratio of the fibrous binder is 95% or less.

[0031] [9] A fiber-reinforced resin molded product comprising the fiber molded product according to any one of [1] to [8] above, and a resin component impregnated in the fiber molded product.

[0032]

[10] A fibrous binder for a fiber molding, which is a fibrillated cellulose fiber,

[0033] The fibrillated cellulose fibers have a Crill ratio of 1.25 to 3.00.

[0034] The fibrillated cellulose fibers have a microfibrillation ratio of 95% or less.

[0035] Effects of the Invention

[0036] According to one or more aspects of the invention disclosed in this disclosure, a fiber molded product having sufficient strength can be provided.

[0037] In addition, according to one or more aspects of the invention disclosed in this disclosure, a fiber molded product using recycled carbon fibers and having sufficient strength can be provided.

[0038] In addition, according to one or more aspects of the invention disclosed in this disclosure, a fiber molded product can be provided that uses various fiber materials and has sufficient strength.

[0039] Furthermore, according to one or more aspects of the invention disclosed in this disclosure, various excellent composite materials can be provided using the above-mentioned fiber molded product. DETAILED DESCRIPTION

[0040] This disclosure is an international application based on the Patent Cooperation Treaty, and the language of the original application is Japanese. This disclosure is scheduled to be translated into the language required by each country when entering the designated country and the selected country. In this disclosure, unless otherwise specified, the Japanese nouns can be any singular or plural according to the full text or context of this disclosure. In addition, regarding nouns, when translated into a language that distinguishes between countable nouns and uncountable nouns such as English, and in which countable nouns have a distinction between singular and plural forms, unless otherwise specified, according to the full text or context of this disclosure, the expression in the singular form includes the plural form, and the expression in the plural form includes the singular form.

[0041] Hereinafter, embodiments of the present invention will be described.

[0042] It should be noted that, in this disclosure, regarding the present invention, unless otherwise specified, the term "one embodiment" is an arbitrary one embodiment based on a detailed description of the present invention, and does not deny or limit the existence of other or multiple embodiments. As shown below, there may be multiple embodiments within the scope of the present invention. In addition, multiple embodiments may also be provided as variations such as various combinations of constituent elements (or technical features) shown in this disclosure. In addition, in this disclosure, when abbreviated as "an embodiment", one or more embodiments are included unless otherwise specified.

[0043] In the present disclosure, unless otherwise specified, a description such as “AA to BB” means “above AA and below BB” (here, “AA” and “BB” represent arbitrary numerical values) for a numerical range. In addition, unless otherwise specified, the units for the lower limit and the upper limit are both the same as the units immediately following the latter (i.e., “BB” here). In addition, in the present disclosure, a combination of a lower limit and an upper limit of a numerical range can be arbitrarily selected from a numerical group of lower limits or upper limits exemplarily described as preferred numerical values. In addition, a description such as “X and / or Y” refers to both X and Y or either of them.

[0044] 1. Fibrous binder

[0045] The fibrous binder of the present disclosure is a substance that can be suitably used as a binder for binding main fiber materials constituting the main body of the fiber molded product described in detail below.

[0046] As the fibrous binder, preferably, for example, fibrillated cellulose fibers can be cited. In the present disclosure, "fibrillation" means that the fibers are fuzzed or burred by rubbing or beating the fibers. In other words, it can also be said that small fibers (i.e., fibrils) are raised from the fiber body by rubbing or beating. In the present disclosure, "fibrillated cellulose fibers" refer to cellulose fibers that have been fibrillated and have small fibers (fibrils) raised on the surface.

[0047] Cellulose fibers include, for example, natural cellulose fibers, chemically modified cellulose fibers, and regenerated cellulose fibers. Natural cellulose fibers include, for example, wood pulps such as conifer pulp and broadleaf pulp, and herbaceous pulps such as straw pulp, bamboo pulp, cotton linter pulp, hemp pulp, and kenaf pulp. Chemically modified cellulose fibers include, for example, oxidized, etherified, cationized, or esterified cellulose fibers. Regenerated cellulose fibers include, for example, rayon, cuprammonium fiber, and lyocell fiber.

[0048] That is, fibrillated cellulose can be obtained by, for example, rubbing or beating cellulose fibers using a single disc refiner (SDR), a double disc refiner (DDR), a beater, a mixer, a grinder, a grinding device, etc. to loosen and fluff the surface of the fibers. Alternatively, a suspension or slurry of cellulose fibers can be prepared and subjected to high-speed and high-pressure treatment using a homogenizer.

[0049] The fibrous binder preferably satisfies at least one of the following indices related to properties, etc., or any two or more indices.

[0050] <Freeness>

[0051] In the present disclosure, the so-called "water filterability" is one of the indicators that represent the fibrillation of fibers, and is obtained by the following method: the object test product (in the present disclosure, for example, a fibrous binder) is made into a slurry, and when the water is quickly drained through a specified filter, the degree of water discharged is measured. More specifically, the value of the water filterability in the present disclosure can be obtained by the measurement method used in the following examples, etc. With regard to the water filterability, the higher the value, the easier it is for water to be discharged, which can be evaluated as less fuzzing. On the contrary, the lower the value, the more difficult it is for water to be discharged, which can be evaluated as more fuzzing. It should be noted that the water filterability is also called the beating degree or the freeness.

[0052] The freeness of the fibrous binder may preferably be 0 to 100 ml when measured by a specific test method described in detail below and carried out in Examples, etc. A freeness within such a range contributes to the formation of a fibrous molded body having sufficient strength.

[0053] From the viewpoint of further improving the strength of the fibrous molded body, the lower limit of the freeness of the fibrous binder is most preferably 0 in theory, but may be 5 ml or more in practice.

[0054] On the other hand, the upper limit of the freeness of the fibrous binder may be more preferably 50 ml or less, further preferably 40, 30 or 20 ml or less.

[0055] <Average Fiber Length of Fibrous Binder>

[0056] The average fiber length of the fibrous binder may preferably be 0.30 to 2.50 mm. The average fiber length within this range helps to form a fibrous molded body with sufficient strength. In order to further pursue the strength of the fibrous molded body, more preferred lower and upper limits may be as follows.

[0057] The lower limit of the average fiber length of the fibrous binder may more preferably be 0.35 mm or more, and further preferably be 0.40, 0.45, or 0.50 mm or more.

[0058] The upper limit of the average fiber length of the fibrous binder may more preferably be 2.00, 1.75, or 1.50 mm or less, and further preferably be 1.25 mm or less.

[0059] <Average Fiber Diameter of Fibrous Binder>

[0060] The average fiber diameter of the fibrous binder may preferably be 10.0 to 40.0 μm. The average fiber diameter within this range helps to form a fibrous molded body having sufficient strength. From the viewpoint of further pursuing the strength of the fibrous molded body, more preferred lower and upper limits are as follows.

[0061] The lower limit of the average fiber diameter of the fibrous binder may be more preferably 15.0 μm or more, and further preferably 20.0 μm or more.

[0062] The upper limit of the average fiber diameter of the fibrous binder may be more preferably 38.0 μm or less, and further preferably 35.0 μm or less.

[0063] <Crill ratio of fibrous binder>

[0064] In the present disclosure, the so-called "Crill ratio" refers to the ratio of the amount of light transmitted in the ultraviolet region and the infrared region respectively reduced when light is incident on a slurry of a fibrous binder. For a fibril having a diameter of about 1 / 100 of the fiber, the fiber wall of which is peeled off from the fiber (the main body or trunk of the fiber) by a treatment such as friction or beating, whether it remains attached to the fiber or is separated from the fiber and floats, since it mainly scatters and absorbs light in the ultraviolet region, the transmitted light in the ultraviolet region is reduced relative to the incident light, and the amount of reduction is related to the total surface area of ​​the fibril. On the other hand, the fiber that is not a fibril mainly scatters and absorbs light in the infrared region, so the transmitted light in the infrared region is reduced relative to the incident light, and the amount of reduction is related to the total surface area of ​​the fiber that is not a fibril. Therefore, the Crill ratio is an indicator of the degree of fibrillation of the fibrous binder. The value of the Crill ratio in the present disclosure can be obtained by the measurement method used in the following examples, etc.

[0065] The Crill ratio of the fibrous binder is preferably 1.25 to 3.00. A Crill ratio within such a range contributes to the formation of a fibrous molded body having sufficient strength.

[0066] From the viewpoint of further pursuing the strength of the fibrous molded product, the lower limit of the Crill ratio may be more preferably 1.30 or more, and further preferably 1.35 or more.

[0067] The upper limit of the Crill ratio may more preferably be 2.80, 2.60, or 2.40 or less.

[0068] <Microfiber ratio of fibrous binder (%)>

[0069] In the present disclosure, the so-called fineness ratio is an index indicating the proportion of fine fibers with a fiber length of less than 0.2 mm. The value of the fineness ratio in the present disclosure can be obtained by the measurement method used in the following examples, etc. Fibers that are excessively ground and finely reduced to a fiber length of less than 0.2 mm during the process of fiber fibrillation are considered to have a low contribution to the bonding effect of the fiber molding.

[0070] The fine fiber ratio of the fibrous binder is preferably 10 to 95%. More specifically, it is as follows.

[0071] The upper limit of the microfiber ratio of the fibrous binder is preferably 95% or less. The microfiber ratio within such a range helps to form a fibrous molded body with sufficient strength. From the viewpoint of further pursuing the strength of the fibrous molded body, the upper limit of the microfiber ratio of the fibrous binder may be more preferably 90% or less, and further preferably 85, 80, 75 or 70% or less.

[0072] From the viewpoint of further pursuing the strength of the fibrous molded body, the lower limit of the fine fiber ratio of the fibrous binder can be arbitrarily set, and is usually preferably 10, 20, 30 or 40% or more.

[0073] 2. Fiber molding

[0074] The fiber molded body of the present disclosure is a molded body comprising a main fiber material as a constituent material and a fibrous binder. The shape of the molded body is not particularly limited, and a sheet or plate shape can be cited as a preferred shape. As the fibrous binder, the fibrous binder of the present disclosure described above can be suitably used.

[0075] The main fiber material is a material that forms the main body of the molded body. The content ratio of the main fiber material to the fiber binder is preferably 1 to 20 parts by weight of the fibrous binder relative to 100 parts by weight of the main fiber material.

[0076] Generally speaking, in FRP obtained by impregnating a resin component as a base material (matrix) into a nonwoven fabric (fiber molding) as a substrate and curing it, it is often desired to reduce the amount of binder components in the nonwoven fabric as much as possible. It is speculated that this is because the binder is considered to be an unnecessary component from the perspective of maximizing the original characteristics of the main fiber material. However, it is difficult to produce a fiber molding such as a nonwoven fabric with corresponding strength using only the main fiber material without using a binder. In the production of fiber moldings such as nonwoven fabrics, binders are still inevitable, and there is an aspect of mixing as little as possible.

[0077] In contrast, the fiber molded body of the present disclosure uses the above-mentioned predetermined fibrous binder, so the strength of the fiber molded body can be sufficient. Moreover, it is known that such a fibrous molded body is also excellent in strength when further processed into a form such as FRP.

[0078] As for the amount of the fibrous binder to be added relative to 100 parts by weight of the main fiber material, as described above, any value between 1 and 20 parts by weight can be preferably adopted. More specifically, the amount of the fibrous binder to be added relative to 100 parts by weight of the main fiber material can be 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1 part by weight.

[0079] If expressed as a numerical range, the upper limit of the amount of the fibrous binder to be blended may be more preferably 18 parts by weight or less, and further preferably 15, 13 or 10 parts by weight or less, relative to 100 parts by weight of the main fiber material. On the other hand, the lower limit of the amount of the fibrous binder to be blended may be more preferably 2, 3 or 4 parts by weight or more relative to 100 parts by weight of the main fiber material.

[0080] In order to mix the main fiber material and the fibrous binder, for example, a liquid such as water can be used as a medium, and the main fiber material and the fibrous binder can be added to the liquid and mixed by stirring. When mixing the main fiber material and the fibrous binder, other additives such as a dispersant and a viscous agent can also be added.

[0081] By using a dispersant, hydrophilicity can be imparted to the hydrophobic main fiber material, promoting mutual repulsion of fibers and thus reducing secondary aggregation. Examples of the dispersant include polyoxyalkylene monophenyl ether, polyether urethane resin, and polyoxyethylene polyoxypropylene stearyl ether.

[0082] The amount of the dispersant blended is preferably 1 to 20 parts by weight, more preferably 3 to 10 parts by weight, relative to 100 parts by weight of the main fiber material.

[0083] In addition, by using a thickener, viscosity can be imparted to the slurry, and secondary aggregation of the hydrophobic main fiber material can be reduced. Examples of the thickener include polyethylene oxide and sodium polyacrylate.

[0084] The blending amount of the thickener is preferably 1 to 50 parts by weight, more preferably 5 to 30 parts by weight, based on 100 parts by weight of the main fiber material.

[0085] <Main fiber material>

[0086] As the main fiber material, there is no particular limitation as long as it is a fiber material that can be formed into woven fabrics, knitted fabrics, non-woven fabrics, etc. The main fiber material can be an inorganic fiber or an organic fiber. As inorganic fibers, for example, carbon fibers, glass fibers, metal fibers, etc. can be cited. As organic fibers, for example, it can be "natural fibers" such as cotton, linen, and animal hair, or "synthetic fibers" made from petroleum, etc., or cellulose fibers derived from wood, or "semi-synthetic fibers" or "regenerated fibers" made from natural materials with various treatments. As "synthetic fibers", for example, polyamide fibers, polyester fibers, polyurethane fibers, polyvinyl alcohol fibers, asphalt fibers, polyacrylonitrile (PAN) fibers, phenolic fibers, polyphenylene sulfide fibers, polyvinyl chloride fibers, polypropylene fibers, polyethylene fibers, and polystyrene fibers can be cited. As "regenerated fibers" obtained from natural materials, for example, rayon, cuprammonium fibers, and lyocell fibers can be cited.

[0087] As the main fiber material, preferably, for example, carbon fiber, glass fiber, metal fiber, cellulose fiber, regenerated fiber, semi-synthetic fiber and synthetic fiber can be cited. More specifically, for example, as inorganic fiber, carbon fiber, glass fiber, metal fiber and the like can be cited, and as organic fiber, cellulose fiber, asphalt fiber, PAN fiber, phenolic fiber, PET fiber, aramid fiber and polyphenylene sulfide fiber and the like can be cited. Among them, as the main fiber material, more preferably, carbon fiber, glass fiber, PET fiber and aramid fiber and the like can be cited, and further preferably, carbon fiber can be cited. As carbon fiber, rayon carbon fiber, asphalt carbon fiber, PAN carbon fiber and phenolic carbon fiber and the like can be cited, and activated carbon fiber can also be cited. The main fiber material can be used alone or in combination of two or more.

[0088] Carbon fiber can be the first-time carbon fiber, or it can be the reused carbon fiber (recycled carbon fiber), or it can be their mixed fibers. It should be noted that in the present disclosure, for carbon fiber, the so-called "first use" (or unused) is used as a term relative to the term "reuse (or regeneration)" (Recycled), not the fiber of "reuse (or regeneration)", but refers to a brand-new fiber used for the first time after the fiber is manufactured, such as the so-called virgin fiber. In addition, in the present disclosure, the so-called "reuse (or regeneration)" carbon fiber refers to the used CFRP products (products used for a certain purpose as carbon fiber) discharged from the process scraps generated in the production process and as waste, and the products are used as raw materials for regeneration, and the fibers are recycled after regeneration treatment. In addition, in the present disclosure, about carbon fiber, "reused carbon fiber" is also referred to as "recycled carbon fiber", "recovered carbon fiber" or as commonly referred to as "recycled carbon fiber" (in English, generally also referred to as Recycled Carbon Fiber (abbreviation: rCF)).

[0089] <Average fiber length of main fiber material>

[0090] The average fiber length of the main fiber material may preferably be 1 to 100 mm. The average fiber length within such a range helps to form a fibrous molded body with sufficient strength. In order to further pursue the strength of the fibrous molded body, more preferred lower and upper limits may be as follows.

[0091] The lower limit of the average fiber length of the main fiber material may more preferably be 2, 3 or 4, and further preferably be 5 mm or more.

[0092] The upper limit of the average fiber length of the main fiber material may more preferably be 80, 60, 50, 40 or 30 mm or less, further preferably 20 mm or less.

[0093] <Average fiber diameter of main fiber material>

[0094] The average fiber diameter of the main fiber material may preferably be 1.0 to 50.0 μm. The average fiber diameter within this range helps to form a fibrous molded body having sufficient strength. From the viewpoint of further pursuing the strength of the fibrous molded body, more preferred lower and upper limits are as follows.

[0095] The lower limit of the average fiber diameter of the main fiber material may more preferably be 2.0, 3.0, 4.0 or 5.0 μm or more, and further preferably be 6.0 μm or more.

[0096] The upper limit of the average fiber diameter of the fibrous binder may more preferably be 40.0, 30.0, 20.0 or 15.0 μm or less, and further preferably 10.0 μm or less.

[0097] As a preferred embodiment of the present disclosure, regenerated carbon fiber (rCF: Recycled Carbon Fiber) obtained by separating and recovering carbon fibers contained in FRP, etc. can be suitably used. Such regenerated carbon fibers are usually shorter than the initial fiber length before being processed into FRP, etc., and the surface is also rough. Even if they are processed into non-woven fabrics, the strength is likely to become insufficient. However, by using the above-mentioned fibrous binder of the present disclosure, the non-woven fabric using such regenerated carbon fibers as the fiber material can have sufficient strength. In addition, as another preferred embodiment, regenerated carbon fibers and new carbon fibers (unused carbon fibers) can also be mixed as the main fiber material.

[0098] The method for forming a fiber molded body such as a nonwoven fabric is not particularly limited, and a common method can be used. For example, as a method for producing a nonwoven fabric, a main fiber material cut into an appropriate length can be used as a raw material and a fiber sheet can be obtained by a wet method.

[0099] In addition to the above-mentioned fibrous binder and main fiber material, the molded body of the present disclosure may also use other types of binders and other materials. As such materials, for example, starch, SBR, polyvinyl alcohol aqueous solution, unsaturated polyester aqueous solution, acrylic acid aqueous solution and other binders that can be used in papermaking can be cited. In addition, as a wet heat bonding type, composite fibers such as polyvinyl alcohol-based fibrous binders, core-sheath fibers, parallel fibers, and radially split fibers can also be used. Specifically, for example, combinations of polypropylene (core) and polyethylene (sheath), polypropylene (core) and ethylene vinyl alcohol (sheath), high melting point polyester (core) and low melting point polyester (sheath), high melting point polyester (core) and polyethylene (sheath) can be cited. In addition, as a full melt type, fibers consisting only of polyethylene or polypropylene can also be used. In addition, various fibrillated fibrous binders can also be used. Both synthetic and natural products can be widely used. As such a fibrillated fibrous binder, for example, acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, nylon fibers, aramid fibers, etc. can be included.

[0100] A preferred embodiment of the fiber molded product of the present disclosure may be a fiber molded product molded into a sheet shape. In the case of a sheet-shaped molded product, its basis weight may be preferably 20 to 200 g / m 2 .

[0101] By setting the lower limit of the basis weight to be above the above preferred value, it helps to prevent the tensile strength of the sheet-like molded body from being insufficient. From the viewpoint of preventing the tensile strength of the sheet-like molded body from being insufficient, the lower limit of the basis weight may be more preferably 30 g / m 2 , more preferably 40g / m 2 .

[0102] On the other hand, by setting the upper limit of the basis weight below the above preferred value, it is possible to easily disperse the water and dry the fabric in the manufacturing process. From the perspective of ease of drying, the upper limit of the basis weight may more preferably be 190, 180 or 170 g / m 2 , more preferably 160 or 150 g / m 2 .

[0103] The density of the fiber molded product of the present disclosure may preferably be 0.05 to 0.20 g / cm 3 .

[0104] By setting the lower limit of the density to be above the above preferred value, it is helpful to achieve a good composite balance with the resin when processing into FRP, etc. From the perspective of such composite balance with the resin, the lower limit of the density may be more preferably 0.06 or 0.07 g / cm 3 More preferably, 0.08 or 0.09 g / cm 3 above.

[0105] On the other hand, by making the upper limit of the density below the above preferred value, it is easier to impregnate the resin when processing into FRP, etc. From the perspective of resin impregnation, the upper limit of the density may be more preferably 0.19 or 0.18 g / cm 3 , more preferably 0.17 or 0.16 g / cm 3 .

[0106] The fiber molded body of the present disclosure can be prepared to have good tensile strength. The tensile strength of the fiber molded body of the present disclosure can be appropriately prepared as needed. There are many ways to prepare the tensile strength, for example, it can also be adjusted by the amount of fibrous binder added.

[0107] The tensile strength of the fiber molded product of the present disclosure can be prepared to be, for example, at least 0.06 or 0.07 kN / mm when measured according to the specific test method (using a test piece of 15 mm width and 150 mm length) implemented in the examples described in detail below. As a higher tensile strength, for example, it can be prepared to be 0.10, 0.15, 0.19, 0.21 or 0.22 kN / mm or more, and further can be prepared to be 0.23, 0.25, 0.30 or 0.40 kN / mm or more.

[0108] 3. Application of fiber moldings

[0109] (3.1) The fiber molded body of the present disclosure can be applied to a wide range of applications. For example, various FRPs can be obtained by impregnating a fiber molded body of the present disclosure processed into a sheet shape (also referred to as a fiber molded body sheet) with a resin as a matrix material and curing the impregnated fiber molded body. Examples of FRPs include glass fiber reinforced plastics, carbon fiber reinforced plastics, boron fiber reinforced plastics, and aramid fiber reinforced plastics.

[0110] (3.2) When activated carbon fibers are used as the main material of the fiber molding in the present disclosure, they can be used as liquid-phase and gas-phase adsorbents. As adsorbents, they can be used, for example, in water purification and chemical filters for semiconductor manufacturing clean rooms.

[0111] Example

[0112] The present invention is described in more detail below with reference to the following examples, but the technical scope (or technical range) of the invention proposed by the present disclosure is not limited to the following examples. In addition, when numerical values ​​are used to determine the invention proposed by the present disclosure, the following methods such as the measuring method, the calculation method, and the evaluation method can be used as methods for determining the numerical values.

[0113] <Example FB1 (fibrous binder)>

[0114] (1) Adjustment of pulp slurry

[0115] 300 g of unbeaten LBKP (bleached hardwood pulp) (manufactured by Nippon Paper Industries, Ltd.) was disintegrated to obtain a 3.0% (W / V) pulp.

[0116] (2) Fibrillation

[0117] The obtained pulp slurry was fibrillated by 11 cycles of a single-disc refiner and then diluted with water to obtain a 0.5% (W / V) slurry with a water filtration rate of 32 ml, an average fiber length of 0.78 mm, an average fiber diameter of 20.8 μm, a Crill ratio of 1.37, and a microfiber rate of 48.4%.

[0118] <Example FB2 (fibrous binder)>

[0119] (1) Adjustment of pulp slurry

[0120] 300 g of unbeaten NBKP (bleached conifer pulp) (manufactured by Nippon Paper Industries, Ltd.) was disintegrated to obtain a 3.0% (W / V) pulp.

[0121] (2) Fibrillation

[0122] The obtained pulp slurry was fibrillated by 4 cycles of a single-disc refiner and then diluted with water to obtain a 0.5% (W / V) slurry with a water filtration rate of 15 ml, an average fiber length of 1.03 mm, an average fiber diameter of 28.8 μm, a Crill ratio of 1.63, and a microfiber rate of 49.9%.

[0123] <Example FB3 (fibrous binder)>

[0124] (1) Adjustment of pulp slurry

[0125] The same operation as in Example FB2(1) was carried out to obtain a 3.0% (W / V) slurry.

[0126] (2) Fibrillation

[0127] The obtained pulp slurry was fibrillated by 10 cycles of a single-disc refiner and then diluted with water to obtain a 0.5% (W / V) slurry with a water filtration rate of 0 ml, an average fiber length of 0.56 mm, an average fiber diameter of 25.6 μm, a Crill ratio of 2.14, and a microfiber rate of 59.3%.

[0128] <Comparative Example FB1 (Fiber-like Binder)>

[0129] (1) Preparation of chemically modified pulp

[0130] 40 kg of unbeaten NBKP (manufactured by Nippon Paper Industries, Ltd.) was added to 4000 L of an aqueous solution in which 312 g (0.05 mmol relative to 1 g of absolutely dry cellulose) of TEMPO (manufactured by Sigma Aldrich) and 4112 g (1.0 mmol relative to 1 g of absolutely dry cellulose) of sodium bromide were dissolved and stirred. Then, an aqueous sodium hypochlorite solution was added in such a manner that the sodium hypochlorite concentration became 5.5 mmol / g, and an oxidation reaction was started at room temperature. In view of the decrease in pH during the reaction, a 3 M aqueous sodium hydroxide solution was added successively to adjust the pH to 10. The sodium hypochlorite was consumed, and the reaction was terminated at a time point when the pH in the system no longer changed. After adding hydrochloric acid to the reaction mixture to adjust the pH to 2, dehydration and dilution with water were repeated to fully wash the pulp, and dehydration was performed until the pulp solid content concentration became 20% by weight to obtain a chemically modified pulp with a carboxyl group content of 1.4 mmol / g.

[0131] (2) Fibrillation

[0132] The obtained chemically modified pulp was dispersed in water, sodium hydroxide was added and stirred, thereby obtaining a 1.1% (W / V) pulp with a pH of 7.7. 4300 kg of the obtained pulp was subjected to 20 cycles of circulation operation using a single-flow double-disc refiner at a circulation rate of 80% to fibrillate the pulp, and then diluted with water to obtain a 0.5% (W / V) pulp with a filterability of 0 ml, an average fiber length of 0.29 mm, an average fiber diameter of 30.3 μm, a Crill ratio of 3.33, and a microfiber rate of 99.8%.

[0133] <Comparative Example FB2 (Fiber-like Binder)>

[0134] (1) Adjustment of pulp slurry

[0135] The same operation as in Example FB1(1) was carried out to obtain a 3.0% (W / V) slurry.

[0136] (2) Dilution

[0137] The obtained pulp slurry was diluted with water to obtain a 0.5% (W / V) slurry having a water filterability of 620 ml, an average fiber length of 0.94 mm, an average fiber diameter of 19.8 μm, a Crill ratio of 0.83, and a microfiber ratio of 30.7%.

[0138] <Comparative Example FB3 (Fiber-like Binder)>

[0139] (1) Adjustment of pulp slurry

[0140] The same operation as in Example FB1(1) was carried out to obtain a 3.0% (W / V) slurry.

[0141] (2) Fibrillation

[0142] The obtained pulp slurry was fibrillated by 5 cycles of a single-disc refiner, and then diluted with water to obtain a 0.5% (W / V) slurry with a water filtration rate of 78 ml, an average fiber length of 0.83 mm, an average fiber diameter of 20.2 μm, a Crill ratio of 1.22, and a microfiber rate of 42.6%.

[0143] <Comparative Example FB4 (Fiber-like Binder)>

[0144] (1) Adjustment of pulp slurry

[0145] The same operation as in Example FB2(1) was carried out to obtain a 3.0% (W / V) slurry.

[0146] (2) Dilution

[0147] The obtained pulp slurry was diluted with water to obtain a 0.5% (W / V) slurry having a water filterability of 650 ml, an average fiber length of 2.11 mm, an average fiber diameter of 28.0 μm, a Crill ratio of 0.98, and a microfiber ratio of 13.5%.

[0148] <Comparative Example FB5 (Fiber-like Binder)>

[0149] (1) Adjustment of pulp slurry

[0150] The same operation as in Example FB2(1) was carried out to obtain a 3.0% (W / V) slurry.

[0151] (2) Fibrillation

[0152] The obtained pulp slurry was fibrillated by circulating it twice using a single-disc refiner, and then diluted with water to obtain a 0.5% (W / V) slurry with a water filtration rate of 362 ml, an average fiber length of 1.80 mm, an average fiber diameter of 27.6 μm, a Crill ratio of 1.20, and a microfiber rate of 25.7%.

[0153] <Example S1 (Fiber Molded Body Sheet)>

[0154] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0155] At room temperature, a professional mixer with a power of 2800 W and a capacity of 3.9 L was used to add 0.08 g of a dispersant (an aqueous solution of a polyether polyurethane resin, manufactured by Meisei Chemical Co., Ltd., model PULSETHA) and 140 g of a thickener (a 0.1% (W / W) aqueous solution of polyethylene oxide, manufactured by Meisei Chemical Co., Ltd., model ALKOX SK) to 700 ml of water. After stirring evenly, 1.33 g of regenerated carbon fiber (manufactured by Carbon Fiber Recycle Industry Co., Ltd., a 9 mm sieve product obtained by secondary heating of Toray Industries, Inc. model T800SC scraps, with an average fiber diameter of 7 μm, an average fiber length of 10 mm, and a moisture content of 1.4%) and 16.8 g of the fibrous binder of Example FB1 were added as the main fiber material, and the mixture was stirred at a rotation speed of 15000 rpm for 6 minutes to obtain a slurry. For this slurry, manual sheeting was performed using a circular (16 mm diameter) manual sheeting machine (manufactured by Toshi Seiki Co., Ltd.), and automatic sheet presses (manufactured by Kumagai Riki Kogyo Co., Ltd.) were used to perform 1st pressing (5 minutes) and 2nd pressing (2 minutes) at a standard pressing pressure of 410±10 kPa according to JIS P8222:2015, and then dried in a dryer at 50°C for 30 minutes to obtain the fiber molded body sheet of Example S1(1).

[0156] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0157] As the main fiber material, 1.33 g of carbon fiber (manufactured by Toray Industries, Inc., model T700SC-12K-50C, average fiber diameter 7 μm, average fiber length 12 mm, moisture content 1.0%) was used. Except for this, the same operation was carried out as in the case of formulation (1) to obtain the fiber molded body sheet of Example S1 (2).

[0158] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0159] The fiber molding sheet of Example S1(3) was obtained by following the same procedure as in formulation (1) except that 1.40 g of glass fiber (manufactured by PFG Fiber Glass Corporation, model E225, average fiber diameter 7 μm, average fiber length 5 mm, moisture content 6.0%) was used as the main fiber material.

[0160] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0161] The fiber molding sheet of Example S1(4) was obtained by following the same procedure as in formulation (1) except that 1.40 g of PET fiber (manufactured by Teijin Ltd., model TA04N SD 0.6×5, average fiber diameter 7 μm, average fiber length 5 mm, moisture content 5.9%) was used as the main fiber material.

[0162] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0163] As the main fiber material, 1.43 g of aromatic polyamide fiber (manufactured by DU PONTTORAY CO., LTD., Kevlar (registered trademark) aromatic polyamide fiber staple fiber 1.7 dtex, average fiber diameter 15 μm, average fiber length 6 mm, moisture content 8.2%) was used. Except for this, the same operation was carried out as in the case of formulation (1) to obtain the fiber molding sheet of Example S1 (4).

[0164] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0165] The fiber molded body sheet of Example S1 (5) was obtained in the same manner as in the case of the formulation (1), except that 1.38 g of the regenerated carbon fibers of the formulation (1) and 8.4 g of the fibrous binder of Example FB1 were used as the main fiber materials.

[0166] <Example S2 (Fiber Molded Body Sheet)>

[0167] Using the fibrous binder of Example FB2, the same operations as Examples S1(1) to S1(6) were carried out to obtain five types of fiber molding sheets: Example S2(1), Example S2(2), Example S2(3), Example S2(4), Example S2(5) and Example S2(6).

[0168] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0169] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0170] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0171] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0172] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0173] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0174] <Example S3 (Fiber Molded Body Sheet)>

[0175] Using the fibrous binder of Example FB3, the same operations as Examples S1(1) to S1(6) were performed except for this, thereby obtaining five types of fiber molding sheets: Example S3(1), Example S3(2), Example S3(3), Example S3(4), Example S3(5) and Example S3(6).

[0176] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0177] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0178] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0179] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0180] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0181] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0182] <Comparative Example S1 (Fiber Molded Body Sheet)>

[0183] Using the fibrous binder of comparison example FB1, the same operations as in examples S1(1) to S1(6) were carried out to obtain five types of fiber molding sheets: comparison example S1(1), comparison example S1(2), comparison example S1(3), comparison example S1(4), comparison example S1(5) and comparison example S1(6).

[0184] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0185] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0186] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0187] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0188] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0189] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0190] <Comparative Example S2 (Fiber Molded Body Sheet)>

[0191] Using the fibrous binder of Comparison Example FB2, the same operations as Examples S1(1) to S1(6) were followed to obtain five types of fiber molding sheets: Comparison Example S2(1), Comparison Example S2(2), Comparison Example S2(3), Comparison Example S2(4), Comparison Example S2(5) and Comparison Example S2(6).

[0192] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0193] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0194] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0195] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0196] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0197] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0198] <Comparative Example S3 (Fiber Molded Body Sheet)>

[0199] Using the fibrous binder of comparison example FB3, the same operations as in examples S1(1) to S1(6) were carried out to obtain five types of fiber molding sheets: comparison example S3(1), comparison example S3(2), comparison example S3(3), comparison example S3(4), comparison example S3(5) and comparison example S3(6).

[0200] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0201] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0202] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0203] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0204] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0205] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0206] <Comparative Example S4 (Fiber Molded Body Sheet)>

[0207] Using the fibrous binder of comparison example FB4, the same operations as in examples S1(1) to S1(6) were carried out to obtain five types of fiber molding sheets: comparison example S4(1), comparison example S4(2), comparison example S4(3), comparison example S4(4), comparison example S3(5) and comparison example S3(6).

[0208] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0209] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0210] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0211] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0212] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0213] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0214] <Comparative Example S5 (Fiber Molded Body Sheet)>

[0215] Using the fibrous binder of comparison example FB5, the same operations as in examples S1(1) to S1(6) were followed to obtain five types of fiber molding sheets, namely, comparison example S5(1), comparison example 5(2), comparison example S5(3), comparison example S5(4), comparison example S5(5) and comparison example S5(6).

[0216] Formula (1): Recycled carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0217] Formula (2): Carbon fiber 94% (W / W), fibrous binder 6% (W / W)

[0218] Formula (3): Glass fiber 94% (W / W), fibrous binder 6% (W / W)

[0219] Formula (4): PET fiber 94% (W / W), fibrous binder 6% (W / W)

[0220] Formula (5): Aramid fiber 94% (W / W), fibrous binder 6% (W / W)

[0221] Formula (6): Recycled carbon fiber 97% (W / W), fibrous binder 3% (W / W)

[0222] Various items related to the shape, physical properties and other properties and performance of the fibrous binder, main fiber material and fiber molding are measured and evaluated by the methods shown below. It should be noted that the numerical values ​​and evaluations related to the various shapes, physical properties and other properties and performance shown in this disclosure can be obtained by the following measurement methods and evaluation methods.

[0223] <Fiber Binder Filterability>

[0224] The freeness of the fibrous binder is measured using a Canadian standard freeness tester (manufactured by Tosho Seiki Co., Ltd.) The term "freeness" is also referred to as "freeness" or "beating degree".

[0225] <Fiber Property Evaluation Method>

[0226] For the fibrous binder, the average fiber length (mm), average fiber diameter (μm), Crill ratio and microfiber ratio (%) were measured as follows. In addition, for the main fiber material, the average fiber length (mm), average fiber diameter (μm) and moisture content (%) were calculated as follows.

[0227] <Average fiber length>

[0228] (1) Fiber length of fibrous binder

[0229] Fibers with a fiber length of less than 0.2 mm were removed, and fibers with a fiber length of 0.2 mm or more were diluted so that the solid content of the fibrous binder became 0.1 g and the slurry became 300 cc, and measured using an L&W Fiber Tester Plus Model 912 (manufactured by Lorentzen & Wettre Ltd.).

[0230] (2) Fiber length of main fiber material (regenerated carbon fiber)

[0231] Considering the large deviation of the regenerated carbon fiber, 20 fiber bundles were randomly selected, each fiber bundle was actually measured using a vernier caliper, and their average value was calculated to obtain the value.

[0232] (3) Fiber length of main fiber material (other than recycled carbon fiber)

[0233] Use the value for average fiber length (or cut size) given by the source providing it.

[0234] <Average fiber diameter>

[0235] (1) Average fiber diameter of fibrous binder

[0236] Fibers with a fiber length of less than 0.2 mm were removed, and fibers with a fiber length of 0.2 mm or more were diluted so that the solid content of the fibrous binder became 0.1 g and the slurry became 300 cc, and measured using an L&W fiber tester model 912 (manufactured by Lorentzen & Wettre Ltd.).

[0237] (2) Average fiber diameter of the main fiber material

[0238] Regarding the fiber diameter of the main fiber material, 10 fibers were randomly selected from an image at 500 times magnification using a Schottky field emission scanning electron microscope JSM-7900F (manufactured by JEOL Ltd.) and actually measured, and the average value was calculated based on this to obtain it.

[0239] <Moisture content of the main fiber material>

[0240] Regarding the moisture content of the main fiber material, it was obtained using a halogen moisture analyzer HB43 (manufactured by Mettler-Toledo Ltd.).

[0241] <Crill ratio>

[0242] Ultraviolet or infrared light was incident on the slurry of the fibrous binder, and for each case of the ultraviolet or infrared light source, the reduction amount of the transmitted light relative to the incident light was obtained. The Crill ratio was calculated using the ultraviolet reduction amount and the infrared reduction amount based on the following formula 1. The test slurry was prepared by diluting it so that the solid content of the fibrous binder became 0.1 g and the slurry became 300 cc. As the measuring device, an L&W fiber tester model 912 (Lorentzen & Wettre Ltd.) was used.

[0243] <Formula 1>

[0244] (CR) = (UVR) / (IRR)

[0245] In formula 1, CR, UVR, and IRR are as follows.

[0246] CR: Crill ratio

[0247] UVR: Ultraviolet reduction amount

[0248] IRR: Infrared reduction amount

[0249] <Microfiber ratio>

[0250] The ratio of microfibers (fibers with a fiber length less than 0.2 mm), that is, the microfiber ratio, was calculated by the following formula 2.

[0251] <Formula 2>

[0252] (FR) = (FFL) / (WFL) × 100 (%)

[0253] In formula 2, FR, FFL, and WFL are as follows.

[0254] FR: Microfiber ratio

[0255] FFL: Total length of microfibers (fibers with a fiber length less than 0.2 mm)

[0256] WFL: Total length of all fibers (fibers with a fiber length of less than 0.2 mm + fibers with a fiber length of more than 0.2 mm)

[0257] The FFL and WFL are values ​​measured by diluting the slurry so that the solid content of the fibrous binder becomes 0.1 g and the solid content becomes 300 cc using an L&W fiber tester model 912 (manufactured by Lorentzen & Wettre Ltd.).

[0258] <Dimensions and weight of fiber molding>

[0259] The dimensions of the fiber molded body are obtained by measuring the dimensions using a ruler or the like as described below. The fiber molded body is measured using a sample that has been humidified overnight in an atmosphere of 23°C and 50% RH. The weight of the fiber molded body after humidification is measured using an electronic balance. Using the obtained measured values, the basis weight and density of the fiber molded body are calculated as described below.

[0260] <Thickness of Fiber Molding Body>

[0261] The sheet-shaped fiber molding was measured for sheet thickness (unit: μm) using a thickness tester TM600 (manufactured by Kumagai Riki Kogyo) at a pressing surface pressure of 100 kPa.

[0262] <Basis Weight of Fiber Molding>

[0263] For a sheet-like fiber molding, the basis weight (unit: g / m 2 ).

[0264] <Density of Fiber Molding Body>

[0265] Density of fiber molding (unit: g / cm 3 ), the basis weight of the fiber molding (unit: g / m 2 ) is divided by the sheet thickness (unit: μm) of the fiber molding. The basis weight and sheet thickness of the fiber molding are calculated based on the measurement results based on the above method.

[0266] <Tensile Strength of Fiber Molding>

[0267] The sheet-like fiber molding was conditioned at 23°C and 50% humidity for 12 hours, and a test piece (15 mm in width and 150 mm in length) was cut out in this atmosphere. The tensile strength (kN / m) was measured using a L&W Tensile Tester Model 066 (Lorentzen & Wettre Ltd.).

[0268] The measurement results for the fibrous binder used as the adhesive component are shown in Table 1-1. The measurement results for the sheet-like regenerated carbon fiber molded body of formula (1) (94% regenerated carbon fiber, 6% adhesive component) are shown in Table 1-2. The measurement results for the sheet-like carbon fiber molded body of formula (2) (94% carbon fiber, 6% adhesive component) are shown in Table 1-3. The measurement results for the sheet-like glass fiber molded body of formula (3) (94% glass fiber, 6% adhesive component) are shown in Table 1-4. The measurement results for the sheet-like PET fiber molded body of formula (4) (94% PET fiber, 6% adhesive component) are shown in Table 1-5. The measurement results for the sheet-like aramid fiber molded body of formula (5) (94% aramid fiber, 6% adhesive component) are shown in Table 1-6. The measurement results for the sheet-like regenerated carbon fiber molded body of formula (6) (94% regenerated carbon fiber, 6% adhesive component) are shown in Table 1-7.

[0269] [Table 1-1]

[0270]

[0271] [Table 1-2]

[0272]

[0273] [Table 1-3]

[0274]

[0275] [Table 1-4]

[0276]

[0277] [Table 1-5]

[0278]

[0279] [Table 1-6]

[0280]

[0281] [Table 1-7]

[0282]

Claims

1. A fiber molding, comprising a main fiber material and a fibrous binder, The content ratio of the main fiber material to the fibrous binder is 1 to 20 parts by weight of the fibrous binder relative to 100 parts by weight of the main fiber material. The Crill ratio of the fibrous binder is 1.25 to 3.

00.

2. The fiber molded product according to claim 1, in, The average fiber length of the fibrous binder is 0.30 to 2.50 mm.

3. The fiber molded product according to claim 1, in, The main fiber material is one or more selected from the group consisting of carbon fiber, glass fiber, metal fiber, natural fiber, cellulose fiber, regenerated fiber, semi-synthetic fiber and synthetic fiber.

4. The fiber molded product according to claim 1, in, The main fiber material is one or more selected from the group consisting of carbon fiber, glass fiber, PET fiber and aramid fiber.

5. The fiber molded product according to claim 1, in, The main fiber material is carbon fiber.

6. The fiber molded product according to claim 5, in, The carbon fiber is first-use carbon fiber, recycled carbon fiber or a mixed fiber thereof.

7. The fiber molded product according to claim 1, in, The fibrous binder is fibrillated cellulose fiber.

8. The fiber molded product according to claim 1, in, The microfiber ratio of the fibrous binder is 95% or less. 9 . A fiber-reinforced resin molded product comprising the fiber molded product according to claim 1 , and a resin component impregnated in the fiber molded product.

10. A fibrous binder for a fiber molding, which is a fibrillated cellulose fiber, The fibrillated cellulose fibers have a Crill ratio of 1.25 to 3.00, The fibrillation rate of the fibrillated cellulose fibers is 95% or less.

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