Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J11/00—Recovery or working-up of waste materials
  • C08J11/04—Recovery or working-up of waste materials of polymers
  • C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
  • C08J11/12—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by dry-heat treatment only
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K7/00—Use of ingredients characterised by shape
  • C08K7/02—Fibres or whiskers
  • C08K7/04—Fibres or whiskers inorganic
  • C08K7/06—Elements
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
  • C08L33/04—Homopolymers or copolymers of esters
  • C08L33/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
  • C08L33/10—Homopolymers or copolymers of methacrylic acid esters
  • C08L33/12—Homopolymers or copolymers of methyl methacrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
  • C08L67/03—Polyesters derived from dicarboxylic acids and dihydroxy compounds the dicarboxylic acids and dihydroxy compounds having the carboxyl- and the hydroxy groups directly linked to aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L69/00—Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/507—Polyesters
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/37—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/507—Polyesters
  • D06M15/513—Polycarbonates
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
  • D06M2101/40—Fibres of carbon

Definitions

• the present invention mainly relates to a fiber-reinforced resin substrate consisting of a resin composition and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing dispersed discontinuous fibrous fillers, and a method for producing the same. It also includes a reinforcing fiber bundle obtained by reusing such a fiber-reinforced substrate, a fiber-reinforced resin composition using the same, and methods for producing the same.
• Fiber-reinforced composite materials consisting of reinforcing fibers and matrix resins, have been used for structural materials for aircraft and automobiles, as well as for sports and general industrial applications such as tennis rackets, golf shafts, and fishing rods, taking advantage of their high specific strength and specific elasticity.
• reinforcing fibers include glass fiber, aramid fiber, carbon fiber, and boron fiber.
• Both thermosetting and thermoplastic resins can be used as matrix resins, but thermosetting resins are often used from the standpoint of heat resistance and productivity.
• thermosetting resins that are generally used include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, bismaleimide resins, and cyanate resins.
• Methacrylic resin (polymethyl methacrylate) is a resin that is widely used in automobile parts, home appliances, aquariums, outdoor signs, liquid crystal displays, building materials, etc., because it has high transparency among synthetic resins and also has excellent weather resistance and processability. Another characteristic of polymethyl methacrylate is that it can be depolymerized into monomers with a high yield by heating, making it highly recyclable. Therefore, fiber-reinforced composite materials made from methacrylic resin are expected to be highly recyclable.
• Patent Document 1 discloses a method for producing a transparent glass fiber-reinforced thermoplastic resin composition by mixing a transparent resin component, which is a uniform mixture of 10 to 80% by weight (resin basis) of an acrylic resin mainly made of methyl methacrylate and 90 to 20% by weight (resin basis) of a copolymer basically made of styrene and acrylonitrile, with glass fibers in a molten state.
• a transparent resin component which is a uniform mixture of 10 to 80% by weight (resin basis) of an acrylic resin mainly made of methyl methacrylate and 90 to 20% by weight (resin basis) of a copolymer basically made of styrene and acrylonitrile
• Patent Document 2 also discloses a method for producing a polymer composite material, in which a polymer is prepared that is a homopolymer of methyl methacrylate having a weight-average molecular weight of 100,000 g/mol or more or a copolymer containing at least 70% by weight of methyl methacrylate, the polymer is dissolved in a monomer of methyl methacrylate to form a liquid syrup, and a fiber material is impregnated with the liquid syrup and polymerized.
• thermoplastic resin as the matrix resin, which allows for shorter molding times, does not necessarily require large equipment such as autoclaves, and is recyclable.
• Patent Document 3 proposes a sizing agent containing an acrylic resin-based polymer.
• Non-Patent Document 1 proposes a method of using Polyetherketoneketone (PEKK) oligomer to improve adhesion with PEEK.
• PEKK Polyetherketoneketone
• Patent Document 1 involves mixing molten methacrylic resin and glass fibers in a molten state, but thermoplastic resins containing methacrylic resin have high viscosity in a molten state, which places limitations on the molding method for fiber-reinforced composite materials and the form of the reinforcing fibers.
• Patent Document 2 is a method of obtaining a composite material by in situ polymerization of a thermoplastic (meth)acrylic matrix together with a fiber material, which improves the flexibility of the molding method, but leaves room for improvement in the mechanical properties of the resulting polymer composite material.
• Carbon fiber bundles sized with the sizing agent described in Patent Document 3 are used when the matrix resin is a polymer with a relatively low molding temperature, such as polypropylene, but the heat resistance temperature of the sizing agent is low, leaving room for further improvement when used with thermoplastic resins with higher heat resistance.
• Non-Patent Document 1 uses a low molecular weight sizing agent, so the improvement in properties is limited, and there is room for further improvement.
• the present invention therefore aims to provide a fiber-reinforced resin substrate that is recyclable and has excellent mechanical properties, and a method for producing the same.
• the present invention aims to provide a method for recycling such a fiber-reinforced resin substrate to obtain a raw material composition and re-producing a fiber-reinforced resin substrate, a reinforced fiber bundle that can be recycled and recovered from such a fiber-reinforced resin substrate, has excellent moldability and mechanical properties and can also be used with highly heat-resistant thermoplastic resins, and a method for producing the same, and further a fiber-reinforced resin composition that uses the reinforced fiber bundle and a method for producing the same.
• a methacrylic resin composition containing 70 to 99% by mass of a methacrylic resin (A) and 1 to 30% by mass of at least one water-insoluble amorphous resin (B) different from the methacrylic resin and having a glass transition temperature of 110 ° C. or higher, based on the total mass of the resin composition, and a fiber-reinforced resin substrate comprising a reinforcing fiber substrate having a continuous fibrous filler or a reinforcing fiber substrate having a discontinuous fibrous filler dispersed therein.
• the water-insoluble amorphous resin (B) is at least one selected from the group consisting of polycarbonate, polyarylate, polysulfone, polyetherimide, polyethersulfone, polyamideimide and polyimide.
• a method for producing a fiber-reinforced resin substrate comprising impregnating a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein with a raw material composition containing at least a monomer for forming a methacrylic resin (A), a water-insoluble amorphous resin (B), and a polymerization initiator, and polymerizing the raw material composition.
• A methacrylic resin
• B water-insoluble amorphous resin
• polymerization initiator a polymerization initiator
• a method for producing a fiber-reinforced resin substrate comprising the following steps in order: (i) Recycling step: A step of heating the fiber-reinforced resin substrate according to any one of [1] to [5] above to 300°C or higher to depolymerize the methacrylic resin and obtain methyl methacrylate.
• Polymerization step A step of impregnating a raw material composition containing at least all or a part of the methyl methacrylate, a water-insoluble amorphous resin (B), and a polymerization initiator into a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein, and polymerizing the resulting composition.
• Reinforced fiber bundle having 1.0 to 20 mass% of a water-insoluble amorphous resin (B) having a glass transition temperature of 110°C or higher, different from the methacrylic resin, attached thereto.
• the water-insoluble amorphous resin (B) is at least one resin selected from the group consisting of polycarbonate, polyarylate, polysulfone, polyetherimide, polyethersulfone, polyamideimide, and polyimide. Reinforced fiber bundle according to [11] or [12].
• a fiber-reinforced resin composition comprising a reinforcing fiber bundle having 1.0 to 20 mass% of a water-insoluble amorphous resin (B) having a glass transition temperature of 110 ° C. or higher other than a methacrylic resin attached thereto, and a matrix resin.
• a method for producing a reinforcing fiber bundle comprising: a fiber-reinforced resin substrate comprising a methacrylic resin composition containing at least a methacrylic resin (A) and a water-insoluble amorphous resin (B) different from the methacrylic resin and having a glass transition temperature of 110°C or higher; and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein; heating the fiber-reinforced resin substrate to 300°C or higher to depolymerize the methacrylic resin (A) and obtain a reinforcing fiber bundle having 1.0 to 20 mass% of a methacrylic resin composition residue adhered thereto.
• a method for producing a fiber-reinforced resin composition comprising the following steps in order: (i) Recycling step: A fiber-reinforced resin substrate comprising a methacrylic resin composition containing at least a methacrylic resin (A) and a water-insoluble amorphous resin (B) different from the methacrylic resin and having a glass transition temperature of 110 ° C. or higher, and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein, is heated to 300 ° C.
• a fiber-reinforced resin substrate having excellent toughness and recyclability can be obtained. Furthermore, according to the present invention, by recycling the fiber-reinforced resin substrate, a reinforced fiber bundle that can achieve both good moldability and mechanical properties, a fiber-reinforced resin composition that has excellent mechanical properties at high temperatures, and a molded product thereof can also be obtained.
• the fiber-reinforced resin substrate of the present invention, and the fiber-reinforced resin composition using the reinforced fiber bundle of the present invention, or a molded product thereof can be used, for example, as electrical/electronic device parts, industrial device parts, automobile parts, aircraft parts, and blade members.
• the fiber-reinforced resin substrate of the present invention comprises a methacrylic resin composition containing 70 to 99 mass% of a methacrylic resin (A) and 1 to 30 mass% of at least one water-insoluble amorphous resin (B) that is different from the methacrylic resin and has a glass transition temperature of 110°C or higher, relative to the total mass of the resin composition (i.e., of the total mass), and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein.
• the fiber-reinforced resin substrate of the present invention may contain substances other than the methacrylic resin composition and the reinforcing fiber substrate, as long as the effects of the present invention are not impaired.
• the methacrylic resin (A) in the present invention is a compound having methyl methacrylate as a main constituent unit, and is preferably a homopolymer or copolymer containing 80 mol % or more of methyl methacrylate, more preferably a homopolymer or copolymer containing 90 mol % or more of methyl methacrylate, and even more preferably a homopolymer substantially composed of methyl methacrylate.
• a copolymerization component that is copolymerizable with methyl methacrylate.
• specific examples include methacrylic acid alkyl esters having an alkyl group with about 1 to 8 carbon atoms, acrylic acid alkyl esters having an alkyl group with about 1 to 8 carbon atoms, or styrene-based monomers such as styrene, ⁇ -methylstyrene, vinyl toluene, and halogenated styrenes, vinyl cyanides such as acrylonitrile and methacrylonitrile, unsaturated acids such as acrylic acid, methacrylic acid, maleic anhydride, and itaconic anhydride, maleimides such as N-methylmaleimide and N-cyclohexylmaleimide, unsaturated alcohols such as methallyl alcohol and allyl alcohol, and compounds such as vinyl acetate, vinyl chloride, ethylene, and propylene.
• methyl methacrylate is the main constituent unit, it may contain a small amount of branched or crosslinked structures.
• Methods for introducing branched or crosslinked structures include copolymerization of polyfunctional monomers, such as polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate, alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, and allyl cinnamate, polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate, and aromatic polyalkenyl compounds such as divinylbenzene.
• polyfunctional monomers such as polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butaned
• the copolymerization amount of these branched or crosslinked units is preferably in the range of 0 to 5 mol% per mol of methyl methacrylate, and more preferably does not substantially contain branched or crosslinked units.
• components that form branched or crosslinked structures tend to be thermally decomposed during recycling and mixed into the recovered methyl methacrylate, lowering the purity.
• the molecular weight of the methacrylic resin (A) in the present invention there is no particular restriction on the molecular weight of the methacrylic resin (A) in the present invention, but examples of preferred weight-average molecular weights include 10,000 to 2,000,000, and more preferably 30,000 to 1,000,000. Methacrylic resin (A) having a weight-average molecular weight in this range tends to improve the properties of the fiber-reinforced resin substrate.
• the weight-average molecular weight is a value measured by gel permeation chromatography (GPC).
• the polymerization method for the methacrylic resin (A) in the present invention is not particularly limited, and any known polymerization method can be used, but an in-situ polymerization type polymerization method is preferred in which a raw material composition containing at least the monomer that forms the methacrylic resin (A), the water-insoluble amorphous resin (B), and a polymerization initiator is impregnated into a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein, and then polymerized.
• the water-insoluble amorphous resin (B) in the present invention is a thermoplastic resin, different from the methacrylic resin (A), and has a glass transition temperature of 110° C. or higher.
• the water-insoluble amorphous resin include polycarbonate, polyarylate, polysulfone, polyetherimide, polyethersulfone, polyamideimide, polyimide, and other water-insoluble amorphous resins and their precursor polymers, and at least one selected from the group consisting of these.
• water-insoluble means that the solubility in water at 25° C. is less than 0.1% by mass.
• amorphous resin means that the molecular structure of the polymer is This refers to a polymer that does not crystallize because it has no periodic parts in its stereoregularity, or a polymer that is extremely difficult to crystallize.
• the glass transition temperature of the water-insoluble amorphous resin (B) in the present invention is 110°C or higher, preferably 115°C or higher, and more preferably 120°C or higher.
• Fiber-reinforced resin substrates used in wind turbine blades and the like are required to have high-temperature rigidity, and resins for fiber-reinforced resin substrates are generally required to have heat resistance around 100°C.
• the glass transition temperature can be measured by differential scanning calorimetry, and the inflection point of the baseline shift detected when the temperature is increased at a rate of 10°C/min was taken as the glass transition point.
• the thermal stability of the water-insoluble amorphous resin (B) in the present invention is preferably 350°C or higher, more preferably 380°C or higher, even more preferably 400°C or higher, and even more preferably 410°C or higher.
• the water-insoluble amorphous resin (B) does not decompose in the recycling process and adheres as a sizing agent to the surface of the reinforcing fibers such as recovered carbon fibers, which tends to improve the processability of the recycling process and the quality of the reinforcing fibers such as recovered carbon fibers.
• the 5% mass reduction temperature is the temperature at which the mass reduction rate from the start of measurement reaches 5% when heated from 50°C at a heating rate of 10°C/min in a non-oxidizing atmosphere in thermogravi
• the weight average molecular weight of the water-insoluble amorphous resin (B) in the present invention is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 20,000 or more.
• the weight average molecular weight is a value measured by gel permeation chromatography (GPC).
• the water-insoluble amorphous resin (B) is preferably soluble in methyl methacrylate at 25°C in an amount of 1% by mass or more, more preferably soluble in 5% by mass or more, and even more preferably soluble in 10% by mass or more.
• the solubility There is no upper limit to the solubility, but 100% by mass or less is an example, and 50% by mass or less is also a preferred example.
• the water-insoluble amorphous resin (B) when a reinforcing fiber bundle is produced by the method described later in section (11), the water-insoluble amorphous resin (B) can be uniformly attached to the surface of the reinforcing fiber. Furthermore, by using such a water-insoluble amorphous resin (B), the impregnation with methyl methacrylate and the opening of the reinforcing fiber bundles in methyl methacrylate are excellent, so that the molding processability is excellent when manufacturing a fiber-reinforced resin substrate with a methacrylic resin matrix by an in-situ polymerization method using methyl methacrylate.
• the methacrylic resin composition in the present invention is a resin composition containing 70 to 99 mass% of a methacrylic resin (A) and 1 to 30 mass% of at least one water-insoluble amorphous resin (B) other than the methacrylic resin, based on the total mass of the resin composition.
• the ratio of the water-insoluble amorphous resin (B) to the total mass of the resin composition is more preferably 3 to 29 mass%, and even more preferably 5 to 28 mass%. If the content of the water-insoluble amorphous resin (B) is less than 1 mass%, the effect of improving the mechanical properties of the fiber-reinforced resin substrate is limited. If the content of the water-insoluble amorphous resin (B) is more than 30 mass%, the viscosity of the raw material composition tends to be high and moldability is poor when manufacturing a fiber-reinforced resin substrate by the method described below in section (6).
• the ratio of the methacrylic resin (A) to the total mass of the resin composition is more preferably 71 to 97 mass%, and even more preferably 72 to 95 mass%. When it is in this preferred range, it tends to have an excellent balance of moldability when manufacturing a fiber-reinforced resin substrate by the method described in (6) below, the mechanical properties of the fiber-reinforced resin substrate, and recyclability.
• the method for producing the methacrylic resin composition there are no particular limitations on the method for producing the methacrylic resin composition, and any known method can be used, but a method for producing the methacrylic resin composition by polymerizing a raw material composition containing a monomer for forming the methacrylic resin (A), a water-insoluble amorphous resin (B), and a polymerization initiator is preferred.
• a methacrylic resin composition in which the methacrylic resin (A) and the water-insoluble amorphous resin (B) are compatible can also be preferably used.
• compatibility refers to a state in which the methacrylic resin (A) and the water-insoluble amorphous resin (B) are uniformly mixed at the molecular level, and means a case in which a phase structure of 0.01 ⁇ m or more is not formed. Compatibility can be determined using an electron microscope or a differential scanning calorimeter.
• the polymerization initiator is not particularly limited as long as it has the ability to initiate the polymerization of the polymerizable monomer with methyl methacrylate as the main monomer, and can be appropriately selected from known polymerization initiators.
• Specific examples include thermal polymerization initiators that initiate polymerization by heating, such as organic peroxides such as lauroyl peroxide and benzoyl peroxide, and azo compounds such as azobisisobutyronitrile.
• the polymerization initiator may be used alone or in combination of two or more.
• a polymerization initiator When a polymerization initiator is used, its amount can be appropriately determined depending on the type and content of the monomer used, but is usually 0.01 to 5% by mass, for example, relative to the polymerizable monomer.
• a reinforcing fiber substrate with continuous fibrous filler or reinforced fiber substrate with discontinuous fibrous filler dispersed is used.
• fibrous fillers include glass fiber and carbon fiber.
• the shape of these fibrous fillers can include continuous fiber, short fiber such as chopped strand, and whisker shape.
• fiber-reinforced resin substrates There are two types of fiber-reinforced resin substrates: the first type is a fiber-reinforced resin substrate in which a reinforcing fiber substrate containing continuous fibrous fillers is impregnated with a methacrylic resin composition, and the second type is a fiber-reinforced resin substrate in which a reinforcing fiber substrate containing dispersed discontinuous fibrous fillers is impregnated with a methacrylic resin composition.
• the reinforcing fiber substrate with continuous fibrous filler refers to one in which the fibrous filler is uninterrupted.
• Examples of the form and arrangement of the continuous fibrous filler include those pulled together in one direction, woven fabric (cloth), knitted fabric, braided cord, tow, etc.
• a reinforcing fiber substrate in which the fibrous filler is arranged in one direction is preferred, as this allows for efficient improvement of the mechanical properties in a specific direction.
• the reinforcing fiber substrate in which the discontinuous fibrous filler is dispersed refers to a mat-like structure in which the fibrous filler is cut and dispersed in the fiber-reinforced resin substrate.
• a mat-like structure in which the fibrous filler is cut and dispersed to a length of 6 mm or more and 100 mm or less is preferred.
• the reinforcing fiber substrate can be obtained by any method, such as a wet method in which the fibrous filler is dispersed in a solution and then manufactured into a sheet, or a dry method using a carding device or an airlaid device. From the viewpoint of productivity, a dry method using a carding device or an airlaid device is preferred.
• the lower limit of the number-average fiber length of the discontinuous fibrous filler in the reinforcing fiber substrate is preferably 7 mm or more, more preferably 8 mm or more. If the number-average fiber length of the discontinuous fibrous filler is less than 6 mm, it becomes difficult to maintain the shape of the reinforcing fiber substrate in the form of a mat in which discontinuous fibers are dispersed, and the mechanical properties of the resulting fiber-reinforced resin substrate may be reduced.
• the upper limit of the number average fiber length of the discontinuous fibrous filler is preferably 90 mm or less, more preferably 80 mm or less, and even more preferably 70 mm or less. If the number average fiber length of the discontinuous fibrous filler is longer than 100 mm, the moldability of the resulting fiber-reinforced resin substrate may decrease.
• the number average fiber length of the discontinuous fibrous filler can be adjusted to the above range by cutting the fibers to the desired length during the production of the reinforcing fiber substrate.
• Method for producing fiber-reinforced resin substrates include a film method in which a film-like methacrylic resin composition is layered on a reinforcing fiber substrate of a continuous fibrous filler or a reinforcing fiber substrate in which a discontinuous fibrous filler is dispersed, and the methacrylic resin composition is melted and impregnated by heating and pressurizing, and a powder method in which a powdered methacrylic resin composition is dispersed in the gaps between fibers in a reinforcing fiber substrate of a continuous fibrous filler or a reinforcing fiber substrate in which a discontinuous fibrous filler is dispersed, and then the powdered methacrylic resin composition is melted and pressurized to impregnate the fibrous filler.
• a raw material composition containing at least a monomer forming a methacrylic resin (A), a water-insoluble amorphous resin (B), and a polymerization initiator is impregnated into a reinforcing fiber substrate of a continuous fibrous filler or a reinforcing fiber substrate in which a discontinuous fibrous filler is dispersed, and polymerized. In-situ polymerization is preferred.
• thermosetting resins When using the in-situ polymerization method, known molding methods commonly used with thermosetting resins can also be applied. Specific examples include resin transfer molding (RTM), hand lay-up, pultrusion, filament winding, sheet molding compound (SMC), and infusion molding.
• RTM resin transfer molding
• SMC sheet molding compound
• the monomer that forms the methacrylic resin (A) is a polymerizable monomer that contains at least methyl methacrylate, and preferably contains 80 mol% or more of methyl methacrylate relative to the total amount of polymerizable monomers, more preferably contains 90 mol% or more of methyl methacrylate, and even more preferably contains substantially only methyl methacrylate.
• a polymerizable monomer means a monomer that has a polymerizable functional group.
• Examples of polymerizable monomers copolymerizable with methyl methacrylate include alkyl methacrylate esters having an alkyl group with 1 to 8 carbon atoms, alkyl acrylate esters having an alkyl group with 1 to 8 carbon atoms, styrene-based monomers such as styrene, ⁇ -methylstyrene, vinyl toluene, and halogenated styrenes, vinyl cyanides such as acrylonitrile and methacrylonitrile, unsaturated acids such as acrylic acid, methacrylic acid, maleic anhydride, and itaconic anhydride, maleimides such as N-methylmaleimide and N-cyclohexylmaleimide, unsaturated alcohols such as methallyl alcohol and allyl alcohol, and compounds such as vinyl acetate, vinyl chloride, ethylene, and propylene.
• alkyl methacrylate esters having an alkyl group with 1 to 8 carbon atoms
• polyfunctional monomers such as polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate; alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl methacrylate, and allyl cinnamate; polyalkenyl esters of polybasic acids such as diallyl phthalate, diallyl maleate, triallyl cyanurate, and triallyl isocyanurate; and aromatic polyalkenyl compounds such as divinylbenzene.
• polyfunctional monomers such as polyunsaturated carboxylic acid esters of polyhydric alcohols such as ethylene glycol dimethacrylate, butanediol dimethacrylate, and trimethylolpropane triacrylate
• alkenyl esters of unsaturated carboxylic acids such as allyl acrylate, allyl meth
• the viscosity of the raw material composition becomes an appropriate value for the in-situ polymerization method, and tends to have excellent moldability.
• the mass ratio of the methacrylic resin (A) to the water-insoluble amorphous resin (B) in the fiber-reinforced resin substrate can be set to 99:1 to 70:30.
• the polymerization initiator is not particularly limited as long as it has the ability to initiate polymerization of at least a polymerizable monomer containing methyl methacrylate, and examples thereof include the polymerization initiators described in (4) above.
• the polymerization initiator may be used alone or in combination of two or more types.
• the amount of the polymerization initiator used can be appropriately determined depending on the type and content of the polymerizable monomer used, but is typically 0.01 to 7% by mass, and preferably 0.1 to 5% by mass, relative to the polymerizable monomer.
• the preferred viscosity at 30°C of the raw material composition containing at least the monomer forming the methacrylic resin (A), the water-insoluble amorphous resin (B), and the polymerization initiator is 0.01 Pa ⁇ s to 10 Pa ⁇ s, more preferably 0.02 Pa ⁇ s to 5 Pa ⁇ s, and even more preferably 0.03 Pa ⁇ s to 3 Pa ⁇ s.
• the temperature at which the raw material composition containing at least the monomers forming the methacrylic resin (A), the water-insoluble amorphous resin (B), and the polymerization initiator is polymerized is preferably 30°C or higher and 160°C or lower, more preferably 40°C or higher and 150°C or lower, and even more preferably 50°C or higher and 140°C or lower. In such a preferred temperature range, a higher reaction rate can be obtained and the reaction time can be shortened.
• the reaction temperature may be a constant temperature, a temperature that is increased stepwise, or a temperature that is changed continuously.
• the time for polymerizing the raw material composition containing at least the monomer that forms the methacrylic resin (A), the water-insoluble amorphous resin (B), and the polymerization initiator varies depending on the conditions and cannot be uniquely limited, but can be, for example, 1 minute to 10 hours. Within this range, the conversion rate of the monomer that forms the methacrylic resin (A) tends to be sufficiently improved.
• the state of the water-insoluble amorphous resin (B) in the raw material composition containing at least the monomers forming the methacrylic resin (A), the water-insoluble amorphous resin (B), and the polymerization initiator it is preferable that the particles of the water-insoluble amorphous resin (B) are uniformly dispersed in the raw material composition, or that the water-insoluble amorphous resin (B) is dissolved in the raw material composition, and it is particularly preferable that the water-insoluble amorphous resin (B) is dissolved.
• Molded products obtained from the fiber-reinforced resin substrate of the present invention can be used for electronic parts, electrical equipment parts, household and office electrical appliance parts, machine-related parts, optical equipment, precision machinery-related parts, automobile and vehicle-related parts, various aerospace applications, and blade members for wind turbines, drones, helicopters, etc.
• the fiber-reinforced resin substrate of the present invention can also contain antioxidants, heat stabilizers, UV absorbers, colorants, etc., as desired.
• a carbon fiber-reinforced resin substrate containing at least a methacrylic resin, a water-insoluble amorphous resin (B) different from the methacrylic resin having a glass transition temperature of 110°C or higher, and carbon fibers can be depolymerized by heating to 300°C or higher to obtain carbon fibers to which methyl methacrylate and the water-insoluble amorphous resin (B) are attached in an amount of 1.0 to 20% by mass.
• the recovered methyl methacrylate can be used in whole or in part as a raw material composition together with a water-insoluble amorphous resin (B) and a polymerization initiator, and can be impregnated into a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a dispersed discontinuous fibrous filler and polymerized (polymerization step) to produce a fiber-reinforced resin substrate again.
• the recovered reinforcing fiber bundles can be impregnated with a matrix resin to produce a fiber-reinforced resin composition.
• the reinforced fiber bundle of the present invention is characterized in that it has a glass transition temperature of 110 ° C. or higher and is attached with 1.0 to 20 mass% of a water-insoluble amorphous resin (B) different from a methacrylic resin.
• the upper limit of the amount of the water-insoluble amorphous resin (B) attached is preferably 18 mass%, 16 mass%, 14 mass%, or even 10 mass%.
• the lower limit is preferably 2.0 mass%, 2.5 mass%, or even 3.0 mass%.
• the water-insoluble amorphous resin (B) is attached to the reinforced fiber bundle in an amount of 2.0 to 18 mass%, more preferably, 2.5 to 16 mass%, and even more preferably, 3.0 to 14 mass%.
• the fiber-reinforced resin composition can be produced with excellent raw material feedability and high productivity.
• the amount of the water-insoluble amorphous resin (B) attached is less than 1.0 mass%, the feedability is reduced when the fiber-reinforced resin composition is produced by melt-kneading with the matrix resin.
• the amount of the water-insoluble amorphous resin (B) attached is more than 20 mass%, the mechanical properties of the fiber-reinforced resin composition are significantly affected, which is undesirable.
• the content of the water-insoluble amorphous resin (B) in the reinforcing fiber bundle can be measured, for example, by the following method.
• the reinforcing fiber bundle to which the water-insoluble amorphous resin (B) is attached is dissolved using a solvent that dissolves the water-insoluble amorphous resin (B), and filtered using a filter with a pore size that does not allow the reinforcing fibers to pass through.
• the water-insoluble amorphous resin (B) is recovered from the filtrate, and the mass is measured.
• the reinforcing fibers used in the reinforcing fiber bundle of the present invention are glass fibers or carbon fibers, with carbon fibers being particularly preferred.
• carbon fibers there are no particular limitations on the carbon fibers, and various known carbon fibers, such as carbonaceous fibers and graphite fibers produced using polyacrylonitrile (PAN), pitch, rayon, lignin, and hydrocarbon gases, can be used.
• PAN polyacrylonitrile
• PAN-based carbon fibers which can improve mechanical properties, are preferably used.
• the reinforced fiber bundle of the present invention there are no particular limitations on the form of use of the reinforced fiber bundle of the present invention, but it is possible to employ a roving method in which continuous fibers are used directly, a method in which chopped strands cut to a specified length are used, or a method in which the bundle is used in a milled form.
• a roving method in which continuous fibers are used directly, a method in which chopped strands cut to a specified length are used, or a method in which the bundle is used in a milled form.
• the bundle in the form of chopped strands in terms of moldability and mechanical properties.
• the length of the chopped strands there are no particular limitations on the length of the chopped strands, but they are preferably cut to 1 to 20 mm, and more preferably cut to 2 to 10 mm. By having the length of the chopped strands in this range, it is possible to obtain chopped strands that have an excellent balance between feedability during injection molding and mechanical properties.
• carbon fiber bundles in chopped strand form have the problem that, if the amount of sizing agent attached is small, fuzzing occurs in the screw of the raw material feeder during melt-kneading with the matrix resin, making it impossible to steadily feed the fiber to the extruder, and the fiber becomes flocculent and its orientation becomes distorted.
• carbon fiber bundles in chopped strand form are usually manufactured by cutting continuous fiber to which a sizing agent has been applied to a specified length, but if the amount of sizing agent attached is increased, the flexibility of the carbon fiber is lost and it cannot be wound onto a bobbin. For this reason, it is difficult to manufacture continuous fiber with an increased amount of sizing agent attached, and it has also been difficult to manufacture carbon fiber bundles in chopped strand form with an increased amount of sizing agent attached.
• reinforcing fiber bundles are produced by the production method detailed in (11), it is possible to produce reinforcing fiber bundles in the form of chopped strands to which 1.0 to 20 mass % of water-insoluble amorphous resin (B) that has a glass transition temperature of 110°C or higher, different from that of methacrylic resin, is attached, and this can be preferably used when melt-kneading with a matrix resin.
• B water-insoluble amorphous resin
• the water-insoluble amorphous resin (B) in the reinforcing fiber bundle is preferably as described in (2) above.
• a fiber reinforced resin substrate consisting of a methacrylic resin composition containing at least a methacrylic resin (A) and a water-insoluble amorphous resin (B) having a glass transition temperature of 110 ° C. or higher, and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein is heated to 300 ° C. or higher to depolymerize the methacrylic resin (A) and obtain a reinforcing fiber bundle having 1.0 to 20 mass % of the methacrylic resin composition residue attached thereto.
• waste examples include molded products used as industrial equipment parts, electrical and electronic parts, aircraft parts, automobile parts, blade members, etc., unused products, prototypes, product scraps generated in the production process, process scraps, etc.
• Other methods include a method in which the reinforcing fiber bundle is impregnated with an aqueous dispersion of the water-insoluble amorphous resin (B) and the water is evaporated to cause the water-insoluble amorphous resin (B) to adhere to the reinforcing fiber bundle, and a method in which the reinforcing fiber bundle is impregnated with a solution in which the water-insoluble amorphous resin (B) is dissolved and the solvent is evaporated to cause the water-insoluble amorphous resin (B) to adhere to the reinforcing fiber bundle.
• the depolymerization temperature is 300°C or higher, more preferably 320°C or higher, and even more preferably 340°C or higher. At temperatures below 300°C, the depolymerization of the methacrylic resin tends not to proceed sufficiently.
• the reaction temperature may be a constant temperature, a temperature that is increased stepwise, or a temperature that is changed continuously.
• the depolymerization is preferably carried out in a non-oxidizing atmosphere, preferably in an inert gas atmosphere such as nitrogen, helium, or argon, and is particularly preferably carried out in a nitrogen atmosphere from the standpoint of economy and ease of handling.
• a non-oxidizing atmosphere preferably in an inert gas atmosphere such as nitrogen, helium, or argon, and is particularly preferably carried out in a nitrogen atmosphere from the standpoint of economy and ease of handling.
• a method in which the fiber-reinforced resin substrate consisting of the methacrylic resin composition and the reinforcing fiber substrate is crushed before depolymerization to obtain uniform fragments can also be preferably adopted.
• Fiber-reinforced resin composition of the present invention is characterized in that it comprises a reinforcing fiber bundle having 1 to 20 mass% of a water-insoluble amorphous resin (B) having a glass transition temperature of 110°C or higher, which is different from a methacrylic resin, attached thereto, and a matrix resin.
• B water-insoluble amorphous resin
• the matrix resin is preferably a thermoplastic resin such as polyolefin resin, polyamide resin, polyester resin, polyacetal resin, polyphenylene sulfide resin, polyethersulfone resin, polyaryletherketone resin, ABS resin, polycarbonate resin, polyarylate resin, polyetherimide resin, or polysulfone resin, and blends thereof can also be used.
• a thermoplastic resin such as polyolefin resin, polyamide resin, polyester resin, polyacetal resin, polyphenylene sulfide resin, polyethersulfone resin, polyaryletherketone resin, ABS resin, polycarbonate resin, polyarylate resin, polyetherimide resin, or polysulfone resin, and blends thereof can also be used.
• the mixing ratio of the matrix resin to the reinforcing fiber bundles is preferably 5 to 150 parts by mass, more preferably 10 to 120 parts by mass, and even more preferably 15 to 100 parts by mass of the reinforcing fiber bundles per 100 parts by mass of the matrix resin. With such a mixing ratio, it tends to be possible to achieve both sufficient mechanical strength and moldability.
• a reinforcing fiber bundle obtained by the manufacturing method described in the above item (11) can be used.
• a method is preferred in which a fiber-reinforced resin substrate consisting of a methacrylic resin composition containing at least a methacrylic resin and a water-insoluble amorphous resin (B) different from the methacrylic resin and having a glass transition temperature of 110°C or higher, and a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein is heated to 300°C or higher to depolymerize the methacrylic resin, thereby obtaining a reinforcing fiber bundle to which 1.0 to 20 mass % of the methacrylic resin composition residue is attached.
• this method it is possible to reuse the fiber-reinforced resin substrate that was
• the weight average fiber length of the reinforcing fibers in the fiber-reinforced resin composition is not particularly limited, but is preferably in the range of 0.1 to 0.5 mm, more preferably 0.11 to 0.45 mm, and particularly preferably 0.12 to 0.40 mm. If it is less than 0.1 mm, sufficient impact strength and elastic modulus improvement effects may not be obtained, and if it exceeds 0.50 mm, the surface appearance may deteriorate.
• the weight average fiber length is obtained by calculating the results of measuring the lengths of 1,000 fibers by observing the residue under an optical microscope after baking and removing the matrix resin from the obtained pellets or molded products.
• the fiber-reinforced resin composition of the present invention can contain additives such as stabilizers, release agents, ultraviolet absorbers, colorants, flame retardants, flame retardant assistants, anti-dripping agents, lubricants, fluorescent brighteners, phosphorescent pigments, fluorescent dyes, flow modifiers, impact resistance modifiers, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents, infrared absorbers, photochromic agents, fillers other than carbon fiber bundles, other thermoplastic resins, and thermosetting resins, as long as the effects of the present invention are not impaired.
• additives such as stabilizers, release agents, ultraviolet absorbers, colorants, flame retardants, flame retardant assistants, anti-dripping agents, lubricants, fluorescent brighteners, phosphorescent pigments, fluorescent dyes, flow modifiers, impact resistance modifiers, crystal nucleating agents, inorganic and organic antibacterial agents, photocatalytic antifouling agents, infrared absorbers, photochromic agents, fill
• the manufacturing method of the fiber reinforced resin composition of the present invention comprises a recycling step and a mixing step.
• the recycling step includes the step described in the manufacturing method of the reinforced fiber bundle in the above item (11). That is, it includes a step of heating a fiber reinforced resin substrate consisting of a methacrylic resin composition containing at least a methacrylic resin (A) and a water-insoluble amorphous resin (B) different from the methacrylic resin and having a glass transition temperature of 110 ° C. or higher, a reinforcing fiber substrate containing a continuous fibrous filler or a reinforcing fiber substrate containing a discontinuous fibrous filler dispersed therein, to 300 ° C.
• the mixing step is not particularly limited as long as it satisfies the requirements of the present invention, and a known method can be adopted.
• a method of uniformly melt-kneading the entire amount or a part of the reinforcing fiber bundles to which 1.0 to 20% by mass of the methacrylic resin composition residue is attached, obtained in the recycling step, with a single-screw or twin-screw extruder at a temperature equal to or higher than the melting point of the matrix resin, or a method of mixing the reinforcing fiber bundles to which 1.0 to 20% by mass of the methacrylic resin composition residue is attached in a solution in which the matrix resin is dissolved, and then removing the solvent, etc. are preferably used.
• a method of uniformly melt-kneading with a single-screw or twin-screw extruder is preferred, and a method of uniformly melt-kneading with a twin-screw extruder is more preferred in terms of obtaining a resin composition with excellent fluidity and mechanical properties.
• a method of melt-kneading using a twin-screw extruder with L/D ⁇ 30, where L is the screw length and D is the screw diameter is particularly preferred.
• the screw length referred to here refers to the length from the position where the raw material is supplied at the base of the screw to the tip of the screw.
• the methods of feeding each component include, for example, feeding the matrix resin, reinforcing fiber bundles, and other components as required from an inlet installed at the base of the screw, feeding the matrix resin and other components from a main inlet installed at the base of the screw using an extruder with two inlets, feeding the reinforcing fiber bundles and other components as required from a secondary inlet installed between the main inlet and the tip of the extruder, and melt-mixing, and feeding the matrix resin and other components from the main inlet, and feeding the reinforcing fiber bundles and other components as required from both the main inlet and the secondary inlet.
• the method of feeding the matrix resin and other components from the main inlet, feeding the reinforcing fiber bundles and other components as required, and melt-kneading is preferred.
• various products can be manufactured by injection molding the pellets produced as described above.
• injection molding molded products can be obtained using not only normal molding methods but also injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high speed injection molding, depending on the purpose.
• injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and ultra-high speed injection molding, depending on the purpose.
• injection molding methods such as injection compression molding, injection press molding, gas-assisted injection molding, foam molding (including injection of supercritical fluids), insert molding, in-mold coating molding, insulating mold molding, rapid heating and cooling mold molding, two-color molding, sandwich molding, and
• the molded products obtained from the carbon fiber reinforced resin composition of the present invention can be used for a wide range of applications, including electronic parts, electrical equipment parts, household and office electrical appliance parts, machine-related parts, optical equipment, precision machinery-related parts, automobile and vehicle-related parts, and various aerospace applications.
• PMMA Polymethyl methacrylate
• Sumipex (registered trademark) LG35 manufactured by Sumitomo Chemical Co., Ltd.
• glass transition temperature 86°C
• Mw 111,000
• 5% mass loss temperature 340°C
• PC-1, PC-2, PC-3, PAR-1 and PMMA are all water-insoluble amorphous resins.
• PA6 Polyamide 6
• PA6 is a water-insoluble crystalline resin.
• Methyl methacrylate (hereinafter also referred to as MMA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.).
• jER828 is a water-insoluble amorphous resin.
• Carbon fiber> Carbon fiber hereinafter also referred to as CF-1; Toray Industries, Inc. "TORAYCA (registered trademark)" T700SC-12k-50C).
• the glass transition temperature can be measured by differential scanning calorimetry, and the inflection point of the baseline shift detected when the temperature was raised at a rate of 10° C./min was taken as the glass transition temperature.
• Apparatus TA Instruments Q20 Measurement atmosphere: nitrogen gas flow Sample weight: 6 mg.
• 5% mass reduction rate was determined based on the mass after holding at 50° C. for 1 minute, and was defined as the temperature at which the mass had decreased by 5%.
• the arithmetic mean value of the 5% mass reduction rates obtained by performing the measurement three times was defined as the 5% mass reduction temperature.
• Apparatus PerkinElmer TGA7 Measurement atmosphere: Nitrogen flow Heating program: (a) Hold for 1 minute at a program temperature of 50° C. (b) Heat from a program temperature of 50° C. to 500° C. at a heating rate of 10° C./min.
• the content of the methacrylic resin composition residue was determined based on the mass after holding at 50° C. for 1 minute, and was determined as the weight loss rate after heating according to the following program and holding at 550° C. for 30 minutes.
• the arithmetic mean value of the contents of the methacrylic resin composition residue when the measurement was performed three times was determined as the content of the methacrylic resin composition residue.
• Apparatus PerkinElmer TGA7 Measurement atmosphere: Nitrogen flow Heating program: (a) Hold for 1 minute at a program temperature of 50° C. (b) Heat from the program temperature of 50° C. to 550° C. at a heating rate of 10° C./min, and hold at 550° C. for 30 minutes.
• Example 1 Storage Modulus and Its Measurement
• a part of the continuous fiber reinforced resin substrate was cut out, and dynamic viscoelasticity measurement was carried out, and the storage modulus at 25° C. and 100° C. was recorded.
• Example 4 a test piece having a thickness of 2 mm, a width of 4 mm and a length of 3 cm was prepared from the carbon fiber reinforced resin composition pellets using a small injection molding machine (HAAKE MiniJet Pro manufactured by Thermo Fisher Scientific, cylinder temperature 250°C, mold temperature 80°C, injection pressure 450 bar), and dynamic viscoelasticity measurement was performed to record the storage modulus at 25°C and 100°C.
• Apparatus Seiko Instruments Inc. DMS6100 Test mode: Bending (double-supported beam) Test temperature: 20°C to 150°C Heating rate: 2°C/min Test frequency: 1Hz (sine wave mode) Initial force amplitude: 2,000 mN
• MMA purity The purity of MMA was analyzed by gas chromatography (GC) under the following conditions: Equipment: Shimadzu GC-2010 Column: J&W DB-5 0.32 mm x 30 m (0.25 ⁇ m) Carrier gas: Helium Detector: Flame ionization detector (FID) Measurement: A sample (20 mg) was dissolved in chloroform (10 g) and the measurement was performed.
• MMA purity The peak area of MMA relative to the total peak area excluding the peaks derived from the solvent was taken as the MMA purity.
• Example 1 Manufacturing process of continuous fiber reinforced resin substrate> PC-1 (10.0 g) was added to MMA (90.0 g) and stirred at 25° C. At this time, PC-1 was completely dissolved in MMA. To this, “Perkadox (registered trademark)” 16 (1.0 g, manufactured by Kayaku Nouryon Co., Ltd.), “Trigonox (registered trademark)” 121 (1.0 g, manufactured by Kayaku Nouryon Co., Ltd.), and lauroyl peroxide (1.0 g) were added as polymerization initiators and stirred to obtain a raw material mixture (raw material composition). PC-1 was completely dissolved in MMA at 25° C., and the viscosity of this raw material mixture at 30° C. was 0.06 Pa ⁇ s.
• the raw material mixture was impregnated into CF-1, which was aligned in one direction and set in a mold, and the mixture was heated from room temperature to 110°C while being pressurized at a pressure of 10 MPa using a press machine to polymerize the MMA, resulting in a continuous fiber-reinforced resin substrate.
• the obtained continuous fiber reinforced resin substrate was subjected to a three-point bending test in accordance with JIS K7074 (1988) to measure the flexural modulus, flexural strength, and flexural strain at break. Each characteristic was taken as the arithmetic mean value of three measurements.
• This continuous fiber reinforced resin substrate was also observed under an electron microscope at 20,000 times magnification, but no structures of 0.01 ⁇ m or more were observed in the resin portion, confirming that PC-1 and polymethyl methacrylate are compatible.
• the fiber volume content of this continuous fiber reinforced resin substrate was 60%.
• the storage modulus was also measured according to the above ⁇ Measurement of storage modulus>.
• the continuous fiber reinforced resin substrate obtained in the above ⁇ Manufacturing process of continuous fiber reinforced resin substrate> was heated at 350 ° C. for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA, and a carbon fiber bundle I with a methacrylic resin composition residue attached was recovered.
• the content of the methacrylic resin composition residue in the recovered carbon fiber bundle was 4.6% by mass.
• the recovered carbon fiber bundle I was washed with tetrahydrofuran (THF) to dissolve the methacrylic resin composition residue, and reprecipitated in hexane to recover PC-1.
• THF tetrahydrofuran
• the Mw of this PC-1 was 98,000, and the 5% mass reduction temperature was 435 ° C.
• the amount of PC-1 attached to the carbon fiber bundle I was 3.9% by mass, and PC-1 dissolved in MMA at 25 ° C. by 1% by mass or more.
• the carbon fiber bundle I obtained in the above ⁇ Recycling step> was chopped to 6 mm and used for melt kneading with matrix resin (PA6).
• the carbon fiber bundle obtained here chopped to 6 mm had a bundled feel and there was no problem with the feedability from the feeder.
• the gut discharged from the die was immediately cooled in a water bath, pelletized with a strand cutter, and vacuum dried at 100 ° C. for 12 hours to obtain carbon fiber reinforced resin composition pellets.
• Example 2 Manufacturing process of continuous fiber reinforced resin substrate> A continuous fiber reinforced resin substrate was obtained in the same manner as in Example 1, except that PC-2 was used instead of PC-1, and a three-point bending test was carried out. PC-2 was completely dissolved in MMA at 25°C, and the viscosity of the raw material mixture at 30°C was 0.06 Pa ⁇ s. The obtained continuous fiber reinforced resin substrate was observed under an electron microscope at 2,000 times magnification, and a sea-island structure was observed in the resin portion, indicating that PC-2 and polymethyl methacrylate were incompatible. The fiber volume content of this continuous fiber reinforced resin substrate was 60%.
• Example 3 Manufacturing process of continuous fiber reinforced resin substrate> A continuous fiber reinforced resin substrate was obtained in the same manner as in Example 1, except that PAR-1 was used instead of PC-1, and PAR-1 (15.0 g) was added to MMA (85.0 g), and a three-point bending test was carried out. PAR-1 was completely dissolved in MMA at 25°C, and the viscosity of the raw material mixture at 30°C was 0.26 Pa ⁇ s.
• the obtained continuous fiber reinforced resin substrate was observed under an electron microscope at 2,000 times magnification, and a sea-island structure was observed in the resin portion, indicating that PAR-1 and polymethyl methacrylate were incompatible.
• the fiber volume content of this continuous fiber reinforced resin substrate was 60%.
• ⁇ Recycling process> The continuous fiber reinforced resin substrate obtained in the above ⁇ Manufacturing process of continuous fiber reinforced resin substrate> was heated at 350°C for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA, and carbon fiber bundle III with the methacrylic resin composition residue attached was recovered.
• the content of the methacrylic resin composition residue in the recovered carbon fiber bundle was 6.5% by mass.
• the recovered carbon fiber bundle III was washed with tetrahydrofuran (THF) to dissolve the methacrylic resin composition residue, and reprecipitated in hexane to recover PAR-1.
• THF tetrahydrofuran
• the Mw of this PAR-1 was 45,000, and the 5% mass reduction temperature was 470°C.
• the amount of PAR-1 attached to the carbon fiber bundle III was 6.0% by mass, and PAR-1 dissolved in MMA at 25°C by 1% by mass or more.
• Example 1 ⁇ Manufacturing process of continuous fiber reinforced resin substrate> A continuous fiber reinforced resin substrate was obtained in the same manner as in Example 1, except that PMMA was used instead of PC-1, and a three-point bending test was performed. Note that PMMA was completely dissolved in MMA at 25°C, and the viscosity of the raw material mixture at 30°C was 0.04 Pa ⁇ s. The fiber volume content of this continuous fiber reinforced resin substrate was 60%.
• the continuous fiber reinforced resin substrate obtained in the above ⁇ Manufacturing process of continuous fiber reinforced resin substrate> was heated at 350° C. for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA and recover carbon fiber bundle IV.
• the content of the methacrylic resin composition residue in the recovered carbon fiber bundle was 0.6 mass%.
• ⁇ Comparative Example 2> Manufacturing process of continuous fiber reinforced resin substrate> An attempt was made to produce a continuous fiber reinforced resin substrate in the same manner as in Example 1, except that 100.0 g of MMA was used instead of PC-1. However, the polymerization reaction of MMA was slow, and a void-free continuous fiber reinforced resin substrate was not obtained (i.e., a void-containing continuous fiber reinforced resin substrate was obtained).
• Comparing Examples 1, 2, and 3 with Comparative Example 1 it was found that the properties of the continuous fiber reinforced resin substrate are improved by using a methacrylic resin composition containing at least one water-insoluble amorphous resin other than the methacrylic resin. Also, comparing Example 1 with Examples 2 and 3, it was found that the improvement in properties is greater when the methacrylic resin and at least one water-insoluble amorphous resin other than the methacrylic resin are compatible with each other.
• Example 1 by comparing Example 1 with Comparative Example 1, it was found that high-temperature properties were improved by producing a fiber-reinforced resin substrate using at least one water-insoluble amorphous resin that has a glass transition temperature of 110°C or higher, different from that of methacrylic resin.
• Example 4 ⁇ Injection molding process>
• a tensile test was performed on the molded product to measure the tensile modulus, break point, and tensile strength. Each characteristic was the arithmetic average value when the measurement was performed three times.
• Example 5 Manufacturing process of continuous fiber reinforced resin substrate> A continuous fiber reinforced resin substrate was obtained in the same manner as in Example 1, except that PC-1 (5.0 g) was added to MMA (95.0 g). The fiber volume content of this continuous fiber reinforced resin substrate was 60%. PC-1 was completely dissolved in MMA at 25°C, and the viscosity of the raw material mixture at 30°C was 0.03 Pa ⁇ s. In addition, this continuous fiber reinforced resin substrate was observed at 20,000 times magnification with an electron microscope, but no structures of 0.01 ⁇ m or more were observed in the resin part, and it was confirmed that PC-1 and polymethyl methacrylate were compatible.
• the continuous fiber reinforced resin substrate obtained in the above ⁇ Manufacturing process of continuous fiber reinforced resin substrate> was heated at 350°C for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA, and carbon fiber bundles V with methacrylic resin composition residue attached were collected.
• the content of the methacrylic resin composition residue in the collected carbon fiber bundles was 2.5% by mass.
• the collected carbon fiber bundles V were washed with tetrahydrofuran (THF) to dissolve the methacrylic resin composition residue, and reprecipitated in hexane to collect PC-1.
• THF tetrahydrofuran
• Comparing Examples 4 and 5 with Comparative Examples 1 and 4 it was found that by using carbon fiber bundles with a glass transition temperature of 110°C or higher and 1.0 to 20 mass% of a water-insoluble amorphous resin (B) different from methacrylic resin attached, it is possible to achieve both good moldability and mechanical properties.
• B water-insoluble amorphous resin
• Example 6 Provide of carbon fiber CF-2> CF-1 was immersed in acetone for washing and then dried to obtain carbon fiber from which the sizing agent had been removed. The carbon fiber thus obtained was designated CF-2.
• PC-1 was dissolved in chloroform, CF-2 was immersed in the solution, and the chloroform was distilled off to recover carbon fiber bundle VII to which PC-1 was attached.
• the content of PC-1 was calculated from the mass of the carbon fiber bundle before and after immersion, and the content of PC-1 in the recovered carbon fiber bundle was 1.5% by mass.
• the raw material mixture was impregnated into carbon fiber bundle VII, which was aligned in one direction and set in a mold, and the mixture was heated from room temperature to 110°C while being pressurized at a pressure of 10 MPa using a press machine to polymerize the MMA, resulting in a carbon fiber reinforced resin substrate.
• ⁇ Recycling process> The continuous fiber reinforced resin substrate obtained in the above ⁇ Manufacturing process of carbon fiber reinforced resin substrate> was heated at 350° C. for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA. The depolymerized component was recovered as a liquid through a cooling tube, and the purity of the recovered MMA was measured according to the above-mentioned method for measuring MMA purity.
• Example 7 ⁇ Sizing agent application step> The same procedure as in Example 6 was carried out except that PC-3 was used instead of PC-1, and carbon fiber bundle VIII to which PC-3 was attached was recovered.
• the solubility of PC-3 in MMA was less than 1 mass %.
• the content of PC-3 in the recovered carbon fiber bundle was 1.5 mass %.
• a carbon fiber reinforced resin substrate was obtained in the same manner as in Example 6, except that carbon fiber bundles VIII were used instead of carbon fiber bundles VII.
• Example 5 ⁇ Sizing agent application step> The same procedure as in Example 6 was carried out except that jER828 was used instead of PC-1, and a carbon fiber bundle IX having jER828 attached thereto was recovered. The content of jER828 in the recovered carbon fiber bundle was 1.5% by mass.
• a carbon fiber reinforced resin substrate was obtained in the same manner as in Example 6, except that carbon fiber bundles IX were used instead of carbon fiber bundles VII.
• Example 8 ⁇ Manufacturing process of fiber reinforced resin substrate>
• Ten sheets of glass fiber fabric (KS2700 (manufactured by Nitto Boseki Co., Ltd.)) cut to a size of 400 mm x 400 mm were stacked in a mold having a plate-shaped cavity, and the mold was clamped with a press device. At that time, the thickness of the cavity was set so that the fiber volume content of the fiber reinforced resin substrate was 40%.
• the pressure inside the mold was reduced to atmospheric pressure -0.1 MPa by a vacuum pump, and the raw material mixture mixed at the weight ratio described in the ⁇ Manufacturing process of continuous fiber reinforced resin substrate> of Example 1 was injected at a pressure of 0.2 MPa using a resin injector. Thereafter, after reacting at 45 ° C for 2 hours and 30 minutes and at 110 ° C for 30 minutes, the mold was quickly demolded to obtain a fiber reinforced resin substrate.
• ⁇ Recycling process> The fiber-reinforced resin substrate obtained in the above ⁇ Manufacturing process of fiber-reinforced resin substrate> was crushed and heated at 350°C for 1 hour and 30 minutes under a nitrogen gas flow to depolymerize PMMA. The depolymerized components were recovered as a liquid through a cooling tube, and the purity of the recovered MMA was measured according to the method for measuring MMA purity. The purity of the recovered MMA was 96.0%. In addition, a glass fiber bundle I to which a methacrylic resin composition residue was attached was recovered. The content of the methacrylic resin composition residue in the recovered glass fiber bundle I was 4.6% by mass.
• a portion of the recovered glass fiber bundle I was washed with tetrahydrofuran (THF) to dissolve the methacrylic resin composition residue, and then reprecipitated in hexane to recover PC-1.
• the Mw of this PC-1 was 99,000, and the 5% mass loss temperature was 432°C.
• the amount of PC-1 attached to the glass fiber bundle I was 3.8% by mass, and PC-1 dissolved in MMA at 25°C to a concentration of 1% by mass or more.
• the glass fiber bundle I obtained in the above ⁇ Recycling step> was chopped to 6 mm and used for melt kneading with matrix resin (PA6).
• the glass fiber bundle obtained here chopped to 6 mm had a bundled feel, and there was no problem with the feedability from the feeder.
• the gut discharged from the die was immediately cooled in a water bath, pelletized with a strand cutter, and vacuum dried at 100 ° C. for 12 hours to obtain glass fiber reinforced resin composition pellets.
• Example 9 ⁇ Manufacturing process of fiber reinforced resin substrate>
• Ten sheets of carbon fiber fabric plain weave fabric made of "TORAYCA (registered trademark)" T700G-12K-31E) cut to a size of 400 mm x 400 mm were laminated in a mold having a plate-shaped cavity, and the mold was clamped with a press device. At that time, the thickness of the cavity was set so that the fiber volume content of the fiber reinforced resin substrate was 40%.
• the pressure inside the mold was reduced to atmospheric pressure -0.1 MPa by a vacuum pump, and the raw material mixture mixed at the mass ratio described in ⁇ Manufacturing process of continuous fiber reinforced resin substrate> of Example 1 was injected at a pressure of 0.2 MPa using a resin injector. Thereafter, after reacting at 45 ° C for 2 hours and 30 minutes and at 110 ° C for 30 minutes, the mold was quickly demolded to obtain a fiber reinforced resin substrate.
• the fiber-reinforced resin substrate, reinforced fiber bundle, and fiber-reinforced resin composition of the present invention can be subjected to known molding methods, and by taking advantage of their excellent mechanical properties and molding processability, they can be processed into various electrical and electronic components, industrial equipment components, automobile components, aircraft components, etc.

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• 2023
  • 2023-12-19 JP JP2023579458A patent/JPWO2024135676A1/ja active Pending
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