JP6067473B2 - Method for producing fiber reinforced composite and fiber reinforced composite - Google Patents

Description

  The present invention relates to a method for producing a fiber reinforced composite and a fiber reinforced composite.

  In recent years, fiber-reinforced synthetic resins reinforced with fibers are lightweight and have high mechanical strength, so they are used in fields where high mechanical strength and light weight are required, such as the automotive field, ship field, and aircraft field. Is expanding. Among them, in automobile applications, not only mechanical strength and light weight but also shock absorption are required.

  In order to satisfy the above requirements, a fiber reinforced composite has been proposed in which a foam is used as a core material and a fiber reinforced synthetic resin is laminated and integrated on the surface of the core material. Although this fiber reinforced composite is considered to be used for members such as automobile roofs, bonnets, and fenders, it has a problem that it is difficult to form into a desired shape.

  Patent Document 1 discloses a thermoplastic resin in which a fiber reinforced composite sheet material including a thermoplastic resin as a main constituent material and a foam material in part is heated using a heater having a predetermined wavelength and three-dimensionally molded by a mold. A sheet thermoforming method is disclosed.

  However, the thermoplastic resin sheet thermoforming method has a problem that the fiber-reinforced composite sheet cannot be formed into a desired three-dimensional shape because the fiber-reinforced composite sheet is gripped as a whole. In the case where continuous fibers are contained in the fiber reinforced composite sheet or the fiber reinforcing material is a woven fabric or a knitted fabric, there is a problem that even shaping may not be possible.

  Patent Document 2 discloses a sandwich panel composed of a core material and a skin material including a fiber reinforced resin in which a matrix resin is impregnated with reinforcing fibers arranged on both sides of the core material. The fiber contains reinforcing fibers having a tensile modulus of 200 to 850 GPa, the reinforcing fiber content in the skin material is in the range of 40 to 80% by weight, and the apparent density of the core material is smaller than that of the skin material. A fiber reinforced resin sandwich panel is disclosed in which a resin is used and the overall thickness of the sandwich panel is in the range of 0.5 to 5 mm.

  However, as a method of manufacturing the fiber reinforced resin sandwich panel, there is described a method in which a skin material and a core material are laminated and then heated and pressurized at the same time using a hot press device and / or an autoclave device. In this method, only a flat fiber-reinforced resin sandwich panel can be manufactured, and a method for manufacturing a fiber-reinforced resin sandwich panel having a desired three-dimensional shape is not disclosed in Patent Document 2.

JP-A-7-276490 JP 2005-313613 A

  The present invention relates to a method for producing a fiber reinforced composite having a desired shape and capable of producing a fiber reinforced composite having excellent mechanical strength, shock absorption and lightness, and fiber reinforced produced by the production method. Provide a complex.

  The method for producing a fiber-reinforced composite of the present invention includes a laminating step for producing a laminate by laminating a fiber reinforcing material impregnated with a thermoplastic resin or an uncured thermosetting resin on at least one surface of a foamed sheet; The laminate is heated to soften the thermoplastic resin or the uncured thermosetting resin impregnated in the fiber reinforcing material into a fluid state, and then grip the fiber reinforcing material of the laminate. And forming the laminate by press-molding the laminate with a male and female mold while holding the foam sheet.

  First, a laminate M is obtained by laminating a fiber reinforcing material 2 impregnated with a thermoplastic resin or an uncured thermosetting resin (hereinafter sometimes referred to as “reinforcing synthetic resin”) on at least one surface of the foam sheet 1. Manufacture (lamination process). The foamed sheet 1 used in the present invention is not particularly limited as long as it can be molded by press molding. In addition, although FIG. 4 mentioned later showed the case where the fiber reinforcements 2 and 2 were laminated | stacked on both surfaces of the foam sheet 1, you may laminate | stack the fiber reinforcement 2 only on the single side | surface of the foam sheet 1. FIG.

  The synthetic resin constituting the foam sheet is not particularly limited, and examples thereof include polycarbonate resins, acrylic resins, thermoplastic polyester resins, polyphenylene ether resins, polymethacrylimide resins, polyolefin resins, polystyrene resins, and the like. Among them, thermoplastic polyester resins and polyphenylene ether resins are preferred because they are excellent in adhesiveness with thermosetting resins or thermoplastic resins impregnated in fiber reinforcement. In addition, a synthetic resin may be used independently or 2 or more types may be used together.

  The thermoplastic polyester resin is a high molecular weight linear polyester obtained as a result of a condensation reaction between a dicarboxylic acid and a dihydric alcohol. Examples of the thermoplastic polyester resin include an aromatic polyester resin and an aliphatic polyester resin.

  The aromatic polyester resin is a polyester containing an aromatic dicarboxylic acid component and a diol component, such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polycyclohexanedimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, And polyethylene terephthalate is preferred. In addition, an aromatic polyester resin may be used independently or 2 or more types may be used together.

  In addition to the aromatic dicarboxylic acid component and the diol component, the aromatic polyester resin includes, for example, a tricarboxylic acid such as trimellitic acid such as trimellitic acid, a tetracarboxylic acid such as pyromellitic acid, or a polyvalent carboxylic acid such as tricarboxylic acid or its anhydride. Products, triols such as glycerin, and trihydric or higher polyhydric alcohols such as tetraols such as pentaerythritol may be contained as constituent components.

  As the aromatic polyester resin, a recycled material recovered and recycled from a used PET bottle or the like can be used.

  Polyethylene terephthalate may be crosslinked by a crosslinking agent. Known crosslinking agents are used, and examples thereof include acid dianhydrides such as pyromellitic anhydride, polyfunctional epoxy compounds, oxazoline compounds, and oxazine compounds. In addition, a crosslinking agent may be used independently or 2 or more types may be used together.

  When polyethylene terephthalate is crosslinked with a crosslinking agent, the crosslinking agent may be supplied to the extruder together with the polyethylene terephthalate. If the amount of the cross-linking agent supplied to the extruder is too small, the melt viscosity at the time of melting of the polyethylene terephthalate may become too small, and bubbles may be broken, and if it is too much, the melt viscosity at the time of melting of the polyethylene terephthalate. When the foam is produced by extrusion foaming, extrusion foaming may be difficult, so 0.01 to 5 parts by weight with respect to 100 parts by weight of polyethylene terephthalate is preferable. 1 part by weight is more preferred.

  Examples of the aliphatic polyester resin include a polylactic acid resin. As the polylactic acid-based resin, a resin in which lactic acid is polymerized by an ester bond can be used. From the viewpoint of commercial availability and imparting foamability to the polylactic acid-based resin expanded particles, D-lactic acid (D-form) 1 or 2 selected from the group consisting of a copolymer of L-lactic acid (L-form), a homopolymer of either D-lactic acid or L-lactic acid, D-lactide, L-lactide and DL-lactide The above lactide ring-opening polymer is preferred. In addition, polylactic acid-type resin may be used independently, or 2 or more types may be used together.

  As long as the polylactic acid resin does not affect the molding process and the physical properties of the resulting fiber-reinforced composite, as a monomer component other than lactic acid, for example, glycolic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxy Aliphatic hydroxycarboxylic acids such as heptanoic acid; succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, succinic anhydride, adipic anhydride, trimesic acid, propanetricarboxylic acid, pyromellitic acid, pyromellitic anhydride, etc. Aliphatic polycarboxylic acid of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol Aliphatic polyvalent arco such as Or the like may also contain Lumpur.

  As long as the polylactic acid resin does not affect the physical properties of the molding process and the resulting fiber reinforced composite, alkyl group, vinyl group, carbonyl group, aromatic group, ester group, ether group, aldehyde group, amino group, nitrile It may contain other functional groups such as a group and a nitro group. The polylactic acid-based resin may be crosslinked by an isocyanate-based crosslinking agent or the like, or may be bonded by a bond other than an ester bond.

  Examples of the polyphenylene ether resin include a mixture of a polyphenylene ether and a polystyrene resin, a modified polyphenylene ether obtained by graft copolymerization of a styrene monomer with a polyphenylene ether, a mixture of this modified polyphenylene ether and a polystyrene resin, and a phenolic resin. Examples thereof include a block copolymer obtained by oxidative polymerization of a monomer and a styrene monomer in the presence of a catalyst such as an amine complex of copper (II), a mixture of this block copolymer and a polystyrene resin, and the like. In addition, polyphenylene ether resin may be used independently or 2 or more types may be used together.

  Examples of the polyphenylene ether resin include poly (2,6-dimethylphenylene-1,4-ether), poly (2,6-diethylphenylene-1,4-ether), and poly (2,6-dichlorophenylene- 1,4-ether), poly (2,6-dibromophenylene-1,4-ether), poly (2-methyl-6-ethylphenylene-1,4-ether), poly (2-chloro-6-methyl) Phenylene-1,4-ether), poly (2-methyl-6-isopropylphenylene-1,4-ether), poly (2,6-di-n-propylphenylene-1,4-ether), poly (2 -Bromo-6-methylphenylene-1,4-ether), poly (2-chloro-6-bromophenylene-1,4-ether), poly (2-chloro-6-ethylphenyle) 1,4 ether). The degree of polymerization of the polyphenylene ether resin is usually 10 to 5000.

  The acrylic resin is produced by polymerizing a (meth) acrylic monomer. In addition, (meth) acryl means either one or both of acryl and methacryl.

  The (meth) acrylic monomer is not particularly limited, and (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, lauryl (meth) acrylate, (meth ) 2-ethylhexyl acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylamide and the like.

  The acrylic resin may contain a monomer component copolymerizable therewith in addition to the (meth) acrylic monomer. Examples of such monomers include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, crotonic acid, maleic amide, maleic imide and the like.

  The foamed sheet is preferably secondarily foamed in the molding step. In the molding process, the foamed sheet may be partially or wholly stretched to produce a portion having a reduced thickness. Therefore, by subjecting the foamed sheet to secondary foaming by heating during the molding step, the resulting fiber-reinforced composite can be prevented from becoming thin, and a fiber-reinforced composite having a desired thickness can be obtained. By setting the thickness of the foamed sheet constituting the fiber reinforced composite to a sufficient thickness, it is possible to impart excellent shock absorption to the fiber reinforced composite.

  A measure of secondary foaming during the molding process of the foamed sheet includes a heat thickness expansion coefficient at 150 ° C. for 1 minute in the foam sheet (hereinafter sometimes simply referred to as “heat thickness expansion coefficient”).

  If the thermal expansion coefficient of the foamed sheet is too low, the resulting fiber-reinforced composite may have a portion where the thickness of the foamed sheet is reduced, and the impact absorbability of the fiber-reinforced composite may be reduced. If the thermal expansion coefficient of the foamed sheet is too high, the mechanical strength of the fiber-reinforced composite may be reduced, or the load on the mold may be too high. The thermal expansion coefficient of the foamed sheet is preferably 0.5% or more, more preferably 5% or more, and particularly preferably 8% or more. Although it does not specifically limit as an upper limit of the heating thickness expansion coefficient of a foam sheet, 150% or less is preferable and 100% or less is more preferable.

In addition, the heating thickness expansion coefficient of a foam sheet says the value measured in the following way. A flat square test piece having a side of 15 cm is cut out from the foam sheet. The thickness of the test piece is measured at any nine locations, and the arithmetic average value is defined as a thickness T ₁ before heating. Next, the test piece is heated at an ambient temperature of 150 ° C. for 1 minute and then left at 25 ° C. for 60 minutes. Thereafter, the thickness of the test piece is measured at any nine locations, and the arithmetic average value is defined as a thickness T ₂ after heating. Based on the pre-heating thickness T ₁ and the post-heating thickness T ₂ , the heating thickness expansion coefficient of the foamed sheet is calculated by the following formula.
Heat expansion coefficient (%) for 1 minute at 150 ° C in the foam sheet
= 100 × (T ₂ −T ₁ ) / T ₁

  The heating thickness expansion coefficient of the foamed sheet can be controlled by adjusting the amount of residual gas or crystallinity contained in the foamed sheet. That is, the heating thickness expansion coefficient of the foamed sheet can be increased by increasing the amount of residual gas contained in the foamed sheet. Moreover, the thermal expansion coefficient of the foamed sheet can be increased by lowering the crystallinity of the foamed sheet.

Apparent density of the foam sheet is preferably ^{0.05~1.2g / cm 3, 0.08~0.9g / cm} 3 is more preferable. In addition, the density of a foam means the value measured based on JISK7222 "Foamed plastics and rubber | gum-measurement of an apparent density."

  If the apparent density of the foam sheet is too low, the foam sheet may be broken by the pressing force from the fiber reinforcement during press molding. If the apparent density of the foamed sheet is too high, the moldability at the time of press molding is lowered, and there is a possibility that a fiber-reinforced composite having a desired shape cannot be obtained.

  If the amount of residual gas in the foamed sheet (residual foamed gas amount) is too small, secondary foaming of the foamed sheet will be insufficient during press molding, and in the resulting fiber-reinforced composite, there will be a portion where the thickness of the foamed sheet will be reduced. The impact absorbability of the fiber reinforced composite may be reduced, so 0.05% by weight or more is preferable. However, if too much, the mechanical strength of the fiber reinforced composite may be reduced, Since there exists a possibility that a load may become large too much, 0.05 to 2 weight% is preferable and 0.05 to 1 weight% is more preferable.

  The amount of residual gas in the foamed sheet is, for example, a press-fitting gas amount during extrusion foaming, a curing process in which the produced foamed sheet is allowed to stand for a predetermined time at a high temperature after extrusion foaming, or the produced foamed sheet It can be controlled by a method such as an internal pressure application step in which a gas is sealed in a pressure-resistant container and gas is pressed into the container.

The residual gas amount in the foamed sheet is measured as follows. First, the weight W ₁ of the whole foam sheet is measured. Next, the residual gas amount in the foam sheet can be measured using a gas chromatograph. For example, the residual gas amount in the foam sheet can be measured under the following conditions using the following apparatus.

Place 10-30 mg of the foam sheet sample in a 20 mL vial, weigh precisely, seal the vial, set it on a gas chromatograph with an autosampler, and heat the vial at 210 ° C. for 20 minutes. The gas in the upper space is quantitatively analyzed by the MHE (Multiple Headspace Extraction) method, and the gas content W ₂ in the foamed sheet is measured.

The MHE method referred to here is a quantitative method that utilizes the attenuation of the peak area obtained by repeating the release of gas phase gas in gas-solid equilibrium.
[GC measurement conditions]
Measuring device: Gas chromatograph Clarus500 (Perkin-Elmer)
Column: DB-1 (1.0 μm × 0.25 mmφ × 60 m: manufactured by J & W)
Detector: FID
GC oven temperature rising condition: initial temperature 50 ° C. (6 minutes)
Temperature increase rate: 40 ° C / min (up to 250 ° C)
Final temperature: 250 ° C (1.5 minutes)
Carrier gas (He), inlet temperature: 230 ° C, detection temperature: 310 ° C
Range: 20
Vent gas 30 mL / min (He), additional gas 5 mL / min (He)
Gas pressure: Initial pressure 18 psi (10 minutes), pressurization speed: 0.5 psi / min (up to 24 psi)
[HS measurement conditions]
Measuring device: HS autosampler TurboMatrix HS40 (Perkin-Elmer)
Heating temperature: 210 ° C, heating time: 20 minutes, pressurized gas pressure: 25 psi, pressurizing time: 1 minute Needle temperature: 210 ° C, transfer line temperature: 210 ° C, sample introduction time: 0.08 minutes [Calculation conditions]
Standard gas for calibration curve: Gas mixture (manufactured by GL Sciences Inc.)
Mixed gas content: i-butane about 1% by weight, n-butane about 1% by weight, balance nitrogen Calculation method: The amount of gas contained in the sample was calculated by the MHE method. The results were all converted to i-butane.

The amount of residual gas in the foamed sheet can be calculated based on the following formula.
Residual gas amount (% by weight) in the foam sheet = 100 × W ₂ / W ₁

  If the crystallinity of the foamed sheet is too high, the secondary foamability of the foamed sheet is lowered, and the thickness of the foamed sheet of the resulting fiber-reinforced composite is partially or wholly reduced. Since impact absorbability may be lowered, it is preferably 15% or less, and more preferably 10% or less.

  The crystallinity of the foam sheet can be controlled by adjusting the cooling rate of the foam sheet immediately after foaming. For example, the slower the cooling rate of the foam sheet immediately after extrusion foaming, the higher the crystallinity of the foam sheet obtained.

  The crystallinity of the foamed sheet is measured by the method described in JIS K7122: 1987 “Method for measuring transition heat of plastic”.

  Specifically, preferably using a differential scanning calorimeter (trade name “DSC6220 type” manufactured by SII Nano Technology Co., Ltd.), a rectangular parallelepiped shape cut out from the foam sheet so that there is no gap at the bottom of the aluminum measurement container. About 6 mg of the sample is charged, and the sample is held at 30 ° C. for 2 minutes under a nitrogen gas flow rate of 30 mL / min.

Thereafter, a DSC curve is obtained when the sample is heated from 30 ° C. to 290 ° C. at a rate of 10 ° C./min. The reference material at that time was alumina. The degree of crystallinity of the thermoplastic polyester resin foam sheet is the difference between the heat of fusion (mJ / mg) determined from the area of the melting peak and the heat of crystallization (mJ / mg) determined from the area of the crystallization peak. This is the ratio that is gradually determined by the theoretical heat of fusion ΔH ₀ of the crystal. For example, ΔH ₀ of polyethylene terephthalate is 140.1 mJ / mg. The crystallinity of the foam sheet is calculated based on the following formula.
Crystallinity of foam sheet (%)
= 100 × (| heat of fusion (mJ / mg) | − | heat of crystallization (mJ / mg) |) / ΔH ₀ (mJ / mg)

  If the thickness of the foamed sheet is too thin, the impact absorbability of the resulting fiber-reinforced composite may be reduced, and if it is too thick, the press formability may be reduced. 5 mm is more preferable, and 1 to 3 mm is particularly preferable.

  As a manufacturing method of a foam sheet, a known manufacturing method can be used as long as press molding can be performed. Specifically, as a method for producing a foamed sheet, (1) a synthetic resin foamed particle is filled in a mold, and the synthetic resin foamed particle is heated and foamed with a heat medium such as hot water or water vapor. A method of producing a foam having a desired shape by fusing and integrating the foam particles with the foaming pressure of the foam particles (in-mold foam molding method), (2) supplying a synthetic resin to the extruder and a chemical foaming agent or A method of producing a foam by melt-kneading in the presence of a foaming agent such as a physical foaming agent and extrusion foaming from an extruder (extrusion foaming method); (3) supplying a synthetic resin and a chemical foaming agent to the extruder Examples include a method of producing a foamable resin molded body from an extruder by melting and kneading at a temperature lower than the decomposition temperature of the chemical foaming agent, and foaming the foamable resin molded body to produce a foam, and the like. Can be manufactured easily, the above ( Extrusion process) is preferred.

  As a method for producing the synthetic resin foam particles used in the above-mentioned in-mold foam molding method (1), (1) the synthetic resin is supplied into the extruder and melt-kneaded in the presence of a physical foaming agent to the extruder. A method of producing synthetic resin foam particles by cutting a synthetic resin extrudate from an attached nozzle mold while extruding and cooling, and (2) supplying the synthetic resin into the extruder and in the presence of a physical foaming agent. A method of producing a synthetic resin expanded particle by cutting and blowing this synthetic resin extrudate at predetermined intervals by extrusion-foaming from a nozzle die attached to an extruder by melt-kneading, (3) A synthetic resin is supplied into an extruder, melt-kneaded in the presence of a physical foaming agent, extruded and foamed from an annular die or a T-die attached to the extruder to produce a foamed sheet, and the foamed sheet is cut. Synthetic resin by And a method of manufacturing a foam particles.

  The production method of the extrusion foaming method of the above (2) is not particularly limited. For example, a die attached to the tip of the extruder after the thermoplastic resin is supplied to the extruder and melt-kneaded in the presence of a foaming agent. And a method of producing an extruded foam sheet by extrusion foaming. The die is not particularly limited as long as it is widely used in extrusion foaming, and examples thereof include a T die and a circular die.

  In the said manufacturing method, when T-die is used as die | dye, a foamed sheet can be manufactured by carrying out extrusion foaming to a sheet form from an extruder. On the other hand, when a circular die is used as a die, a cylindrical body is produced by extrusion foaming from a circular die into a cylindrical shape, and the cylindrical body is gradually expanded in diameter and then supplied to a cooling mandrel for cooling. After that, the foamed sheet can be manufactured by cutting the cylindrical body continuously between the inner and outer peripheral surfaces in the direction of extrusion, and cutting and opening the cylindrical body.

  Examples of the chemical foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, hydrazoyl dicarbonamide, sodium bicarbonate, and the like. In addition, a chemical foaming agent may be used independently or 2 or more types may be used together.

  Physical foaming agents include, for example, propane, normal butane, isobutane, normal pentane, isopentane, hexane and other saturated aliphatic hydrocarbons, ethers such as dimethyl ether, methyl chloride, 1,1,1,2-tetrafluoroethane, 1 , 1-difluoroethane, chlorofluorocarbons such as monochlorodifluoromethane, carbon dioxide, nitrogen and the like, dimethyl ether, propane, normal butane, isobutane and carbon dioxide are preferred, propane, normal butane and isobutane are more preferred, and normal butane and isobutane are preferred. Particularly preferred. In addition, a physical foaming agent may be used independently or 2 or more types may be used together.

  Next, the fiber reinforcement 2 that is laminated on one surface of the foamed sheet 1 and impregnated with a thermoplastic resin or an uncured thermosetting resin is not particularly limited as long as it can be molded by press molding. The fiber constituting the fiber reinforcing material is not particularly limited, and examples thereof include carbon fiber, glass fiber, aramid fiber, boron fiber, metal fiber, etc., and has excellent mechanical strength and heat resistance. Therefore, carbon fiber, glass fiber, and aramid fiber are preferable, and carbon fiber is more preferable.

  The form of the fiber reinforcement is not particularly limited. For example, a woven fabric, a knitted fabric, a nonwoven fabric, a fiber bundle (strand) in which fibers are aligned in one direction, a synthetic resin yarn such as a polyamide resin or a polyester resin, or a glass fiber yarn. And face materials formed by binding (stitching) with stitch yarns. Examples of the weaving method include plain weave, twill weave and satin weave.

  The fiber reinforcing material is (1) a multi-layered surface material formed by laminating a plurality of face materials including a woven fabric, a knitted fabric or a non-woven fabric, or an arbitrary combination of these surface materials, and (2) a fiber aligned in one direction. A plurality of face materials obtained by binding (sewing) fiber bundles (strands) with synthetic resin yarns such as polyamide resin and polyester resin or stitch yarns such as glass fiber yarns are oriented in directions in which the fiber directions of the fiber bundles are different from each other. The multilayered surface material may be formed by superimposing and superimposing the laminated surface materials together with a synthetic resin yarn such as polyamide resin and polyester resin or stitch yarn such as glass fiber yarn.

  In the multilayer surface material of (1) above, in the case of a multilayer surface material formed by laminating a plurality of woven fabrics, the length direction of the warp (weft) constituting each woven fabric is radially arranged when viewed from the plane direction of the woven fabric. It is preferable that Specifically, as shown in FIGS. 1 and 2, when the length directions of the warps (wefts) constituting each fabric are 1a, 1b,..., The lengths of these warps (wefts) It is preferable that the length directions 1a, 1b... Are arranged radially, and the length direction 1a of any warp (weft) of the warp (weft) length directions 1a, 1b. Are more preferably arranged so that the length directions 1b, 1c,... Of other warps (wefts) are axisymmetric about the length direction 1a of a specific warp (weft).

  In addition, the crossing angle between the length directions 1a, 1b, ... of the warps (wefts) constituting each woven fabric is such that the strength of the fiber reinforcement is not biased in one direction and the mechanical strength is almost the same in any direction. 90 ° is preferable when two woven fabrics are overlapped, and 45 ° is preferable when three or more woven fabrics are overlapped.

  In the multilayer face material of (2) above, it is preferable that the length direction of the fibers of the fiber bundle constituting each face material is arranged radially when viewed from the plane direction of the face material. Specifically, as shown in FIGS. 1 and 2, when the length directions of the fibers of the fiber bundle constituting each face material are 1a, 1b,. 1a, 1b ... are preferably arranged radially, and when any length direction 1a of the fiber length directions 1a, 1b ... is specified, the specific length direction 1a is the center. It is more preferable that the other length directions 1b, 1c,... Are arranged so as to be line symmetric.

  Further, the crossing angle between the length directions 1a, 1b, ... of the fiber bundles constituting each face material is substantially the same in any direction without the strength of the fiber reinforcing material being biased in one direction. Since strength can be imparted, 90 ° is preferable when two face materials are overlapped, and 45 ° is preferable when three or more face materials are overlapped.

  The fiber reinforcement is impregnated with a thermoplastic resin or an uncured thermosetting resin, but an uncured thermosetting resin is preferred. The thermosetting resin is not particularly limited. For example, epoxy resin, unsaturated polyester resin, phenol resin, melamine resin, polyurethane resin, silicon resin, maleimide resin, vinyl ester resin, cyanate ester resin, maleimide resin and cyanide Examples thereof include a resin obtained by prepolymerizing an acid ester resin, and an epoxy resin and a vinyl ester resin are preferable since they are excellent in heat resistance, impact absorption or chemical resistance. The thermosetting resin may contain additives such as a curing agent and a curing accelerator. In addition, a thermosetting resin may be used independently or 2 or more types may be used together.

  Further, the thermoplastic resin is not particularly limited, and examples thereof include olefin resins, polyester resins, thermoplastic epoxy resins, amide resins, thermoplastic polyurethane resins, sulfide resins, acrylic resins, and the like. Polyester resins and thermoplastic epoxy resins are preferred because they are excellent in the adhesion between the fibers constituting the fiber reinforcement or the adhesion between the fibers constituting the fiber reinforcement. In addition, a thermoplastic resin may be used independently or 2 or more types may be used together.

  The thermoplastic epoxy resin may be a polymer or copolymer of epoxy compounds having a linear structure, or a copolymer of an epoxy compound and a monomer that can be polymerized with the epoxy compound. And a copolymer having a linear structure. Specifically, as the thermoplastic epoxy resin, for example, bisphenol A type epoxy resin, bisphenol fluorene type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, cyclic aliphatic type epoxy resin, long chain aliphatic type An epoxy resin, a glycidyl ester type epoxy resin, a glycidylamine type epoxy resin and the like can be mentioned, and a bisphenol A type epoxy resin and a bisphenol fluorene type epoxy resin are preferable. In addition, a thermoplastic epoxy resin may be used independently or 2 or more types may be used together.

  Examples of the thermoplastic polyurethane resin include a polymer having a linear structure obtained by polymerizing diol and diisocyanate. Examples of the diol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, and the like. Diols may be used alone or in combination of two or more. Examples of the diisocyanate include aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Diisocyanate may be used independently or 2 or more types may be used together. In addition, a thermoplastic polyurethane resin may be used independently or 2 or more types may be used together.

  If the content of the reinforcing synthetic resin in the fiber reinforcement is too small, the fiber reinforcement will crack during press molding of the fiber reinforcement, resulting in a decrease in the mechanical strength of the resulting fiber reinforced composite and fiber reinforcement. The bond between the fibers constituting the material becomes weak or the adhesion between the fiber reinforcement and the foam becomes insufficient, the mechanical strength of the resulting fiber reinforced composite decreases, or the fiber reinforcement The fibers constituting the glass fiber are likely to be exposed on the surface of the obtained fiber reinforced composite, and the surface smoothness of the fiber reinforced composite may be lowered. The amount of reinforcing synthetic resin present in the fiber increases too much, and on the contrary, the mechanical strength of the fiber reinforcing material may decrease, and the mechanical strength of the resulting fiber reinforced composite may decrease. Preferably, 30-60% by weight Ri preferred.

  The method for impregnating the reinforcing resin in the fiber reinforcing material is not particularly limited. For example, (1) the fiber reinforcing material is immersed in the reinforcing synthetic resin and the fiber reinforcing material is impregnated with the reinforcing synthetic resin. And (2) a method of applying a reinforcing synthetic resin to a fiber reinforcing material and impregnating the fiber reinforcing material with the reinforcing synthetic resin.

  Commercially available fiber reinforcements and fiber reinforcements impregnated with reinforcing synthetic resin can be used. The fiber reinforcement impregnated with the thermosetting resin is commercially available from Mitsubishi Rayon Co., Ltd. under the trade name “Pyrofil Prepreg”. The fiber reinforcement is commercially available from Mitsubishi Rayon under the trade name “Pyrofil”, for example. The fiber reinforcing material impregnated with the thermoplastic resin is commercially available, for example, from Nagase Chemtech under the trade name “NNGF60-03s”.

  If the thickness of the fiber reinforcement after impregnating the reinforcing synthetic resin is too thin, the fiber reinforcement will crack during press molding of the fiber reinforcement, and the mechanical strength of the resulting fiber-reinforced composite will decrease. In some cases, if it is too thick, the formability during press molding of the fiber reinforcement may be reduced, so 0.02 to 2 mm is preferable, and 0.05 to 1 mm is more preferable.

If the basis weight of the fiber reinforcement after impregnating the reinforcing synthetic resin is too small, the mechanical strength of the fiber-reinforced composite may be reduced, and if too large, the lightweight property of the fiber-reinforced composite will be reduced. Therefore, 50 to 4000 g / m ² is preferable, and 100 to 1000 g / m ² is more preferable.

  As shown in FIG. 3, the fiber reinforcing material 2 may be provided with a cut portion 21 in order to facilitate molding during press molding. In addition, in FIG. 3, although the case where the cut | notch part 21 was formed in the four-way corner part of a plane rectangular fiber reinforcement was shown, it is not limited to this, The shape after press molding of a fiber reinforcement is shown. In addition, the position and shape may be changed as appropriate.

  When laminating the fiber reinforcing material 2 impregnated with the reinforcing synthetic resin on at least one surface of the foam sheet 1, the fiber reinforcing material 2 is disposed on one surface of the foam sheet 1 from the viewpoint of improving the handleability of the laminate in the subsequent process. It is preferable to make temporary adhesion. Temporary adhesion between the foam sheet 1 and the fiber reinforcement 2 may be performed by a reinforcing synthetic resin impregnated in the fiber reinforcement 2, or a known adhesive prepared separately may be used. In addition, it is necessary to perform temporary adhesion | attachment of the foam sheet 1 and the fiber reinforcement material 2 so that the fiber reinforcement material 2 can move freely on the foam sheet 1 at the time of press molding of a subsequent forming process. .

If the temporary adhesive force between the foam sheet 1 and the fiber reinforcement 2 is too low, the foam sheet 1 and the fiber reinforcement 2 may be unexpectedly separated during handling of the laminate, and if too high, the laminate is pressed. At the time of molding, the integration of the fiber reinforcement and the foamed sheet is not released, and it may not be possible to press-mold while sliding the fiber reinforcement on the foamed sheet, so 1 to 300 N / cm ² is preferable. 100 N / cm ² is more preferable. In addition, the temporary adhesive force between the foam sheet 1 and the fiber reinforcement 2 is a shear tension measured at a test speed of 10 mm / min using a test piece cut out from the laminate in accordance with JIS K6850 (1999). I say power. In addition, the temporary adhesive force of the foam sheet 1 and the fiber reinforcement 2 can be measured using a small tabletop testing machine (trade name “FGS-1000TV / 1000N + FGP-100” manufactured by Nidec Shinpo Co., Ltd.).

  Further, a release film 3 may be laminated on the fiber reinforcement 2 of the laminate M in order to improve the releasability from the male and female dies. The release film 3 is composed of a synthetic resin film. The synthetic resin constituting the release film is not particularly limited as long as it has releasability from the fiber reinforcing material 2 and the male and female molds. For example, a tetrafluoroethylene-ethylene copolymer (4 Fluorine resin such as (fluoroethylene-ethylene copolymer), polystyrene resin, polyester resin and the like.

  Next, a molding process is performed following the above-described lamination process. First, as shown in FIG. 4, in the molding step, the foamed sheet 1 of the laminate M is gripped, while the fiber reinforcement 2 is not gripped at all.

  Thus, by not grasping the fiber reinforcement 2, the laminate M can be freely moved on the foam sheet 1 during the press molding of the laminate M, and the fiber reinforcement 2 is stretched along with the press molding of the foam sheet 1. There is no need to follow, the fiber reinforcing material 2 can be independently press-molded smoothly by the male and female dies 41, 42, and the fiber reinforcing material 2, which is difficult to press-mold, can be easily formed on the foam sheet 1. And it can press-mold correctly.

  In addition, the foam sheet 1 is held in a stable position with respect to the male and female molds 41 and 42 when the laminate M is press-molded to stably support the foam sheet 1. 1 can be accurately press-molded, and the fiber reinforcing material 2 can be stably press-molded on the stably supported foamed sheet 1 so as to be molded into a desired shape. The M foam sheet 1 and the fiber reinforcement 2 can be accurately press-formed into a desired shape.

  For example, when the foam sheet 1 is shrunk by heating, which will be described later, the foam sheet 1 is prevented from shrinking by heating, so that the foam sheet 1 is accurate with respect to the male and female molds 41 and 42. It is held so as to be arranged at a proper position. Conversely, when the foamed sheet 1 expands by heating, the foamed sheet 1 is prevented from being wrinkled by pulling the foamed sheet 1 to prevent drawdown due to the expansion of the foamed sheet 1, and foamed. The sheet 1 is held so as to be disposed at an accurate position without generating wrinkles or the like with respect to the male and female molds 41 and 42. Further, even when the foamed sheet 1 does not expand or contract by heating, the foamed sheet 1 can be drawn into the joint surfaces of the male and female dies 41 and 42 during press molding by holding the foamed sheet 1. To prevent the foam sheet 1 from being pressed accurately.

  The foam sheet 1 may be gripped using a known clamp 5. Further, the position where the foam sheet 1 is gripped is not particularly limited as long as the above object is achieved, and examples thereof include the outer peripheral edge portion of the foam sheet 1 facing each other and the four-way outer peripheral edge portion of the foam sheet. .

  As described above, the laminate M is heated after holding the foam sheet 1. By heating the laminate M, the reinforcing synthetic resin impregnated in the fiber reinforcement 2 is softened. When the reinforcing synthetic resin contains an uncured thermosetting resin, the uncured thermosetting resin is softened and brought into a fluid state without being cured. Since the thermosetting resin is in a state having fluidity before being thermally cured by heating, the temperature is controlled so as to maintain the state having this fluidity. When the reinforcing synthetic resin contains a thermoplastic resin, the temperature is controlled so that the thermoplastic resin is in a fluid state. In addition, what is necessary is just to use well-known heating apparatuses, such as an infrared heater, as the heating means of the laminated body M.

  If the heating temperature of the laminated body M is too low, softening of the reinforcing synthetic resin impregnated in the fiber reinforcement becomes insufficient, and the fiber reinforcement is accurately formed along the shape of the male and female molds. If it is too high, bubbles in the foamed sheet may be destroyed by heat, and the resulting fiber-reinforced composite may have reduced lightness and shock absorption. (Temperature-60 ° C.) to (Glass transition temperature of reinforcing synthetic resin + 80 ° C.) is preferred, and (Glass transition temperature of reinforcing synthetic resin−50 ° C.) to (Glass transition temperature of reinforcing synthetic resin + 70 ° C.) is more preferred. . In the present invention, the heating temperature of the laminate M refers to the surface temperature of the fiber reinforcement of the laminate M. When two or more types of thermosetting resins or thermoplastic resins are contained in the reinforcing synthetic resin, the glass transition temperature of the reinforcing synthetic resin is the glass transition temperature of the synthetic resin contained in the reinforcing synthetic resin. Of these, the highest glass transition temperature is used. When two or more types of thermosetting resins are contained in the reinforcing synthetic resin, the heating temperature of the laminate M is adjusted so that all the thermosetting resins are in a fluid state without being cured. There is a need.

  In the present invention, the glass transition temperature of the thermoplastic resin is measured by the method described in JIS K7121: 1987 “Method for measuring plastic transition temperature”. However, the sampling method and temperature conditions are as follows. Using a differential scanning calorimeter device, about 6 mg of the sample is filled so that there is no gap at the bottom of the aluminum measurement container, and the sample is cooled from 30 ° C. to −40 ° C. for 10 minutes under a nitrogen gas flow rate of 20 mL / min. The sample was heated from -40 ° C. to 290 ° C. (1st Heating), held at 290 ° C. for 10 minutes, and then cooled from 290 ° C. to −40 ° C. (Cooling) for 10 minutes. The DSC curve was obtained when the temperature was raised from −40 ° C. to 290 ° C. (2nd Heating). In addition, all the temperature increase rates and temperature decrease rates are performed at 10 ° C./min, and alumina is used as a reference material. In the present invention, the glass transition point means an intermediate point glass transition temperature obtained from a DSC curve obtained in the 2nd Heating process. The midpoint glass transition temperature is obtained from JIS K7121: 1987 (9.3 “How to Obtain Glass Transition Temperature”). In addition, as a differential scanning calorimeter apparatus, the differential scanning calorimeter apparatus marketed by the SII nanotechnology company by the brand name "DSC6220 type | mold" can be used, for example.

  In the present invention, the glass transition temperature of the thermosetting resin refers to a temperature measured in the following manner. When measuring the glass transition temperature of a thermosetting resin, it is necessary to harden the thermosetting resin in advance. The curing temperature of the thermosetting resin is set to an exothermic peak temperature ± 10 ° C. measured in JIS K7121: 1987. The curing time of the thermosetting resin is 60 minutes as a guide. When the exothermic peak of the thermosetting resin after curing is measured according to JIS K7121: 1987, the curing is complete if no exothermic peak is observed. The glass transition temperature of the thermosetting resin is measured in the manner described later using the cured thermosetting resin. In addition, the detailed measuring method of the exothermic peak temperature used as the standard of the curing temperature of the thermosetting resin mentioned above is as follows. The exothermic peak temperature of the thermosetting resin is measured by the method described in JIS K7121: 1987 “Method for measuring plastic transition temperature”. However, the sampling method and temperature conditions are as follows. Using a differential scanning calorimeter device, about 6 mg of the sample is filled so that there is no gap at the bottom of the aluminum measurement container, alumina is used as a reference material under a nitrogen gas flow rate of 20 mL / min, and the sample is heated from 30 ° C. to 220 ° C. The temperature is raised to 5 ° C. at a rate of 5 ° C./min. In the present invention, the exothermic peak temperature of the thermosetting resin is a value obtained by reading the temperature at the peak top at the first temperature rise. In addition, as a differential scanning calorimeter apparatus, the differential scanning calorimeter apparatus marketed by the SII nanotechnology company by the brand name "DSC6220 type | mold" can be used, for example.

  The glass transition temperature of the thermosetting resin is a temperature measured in accordance with 9.3 “How to obtain glass transition temperature” in JIS K7121 (1987) “Method for measuring plastic transition temperature”. Specifically, 6 mg of a thermosetting resin after curing for measuring the glass transition temperature is taken as a sample. Using a differential scanning calorimeter device, the sample was heated from 30 ° C. to 200 ° C. at a rate of temperature increase of 20 ° C./min in a nitrogen gas flow at a flow rate of 20 mL / min. Hold for a minute. Thereafter, the sample is quickly taken out from the apparatus and cooled to 25 ± 10 ° C., and then the sample is again heated to 200 ° C. at a heating rate of 20 ° C./min under a nitrogen gas flow rate of 20 mL / min in the apparatus. The glass transition temperature (intermediate point) is calculated from the DSC curve obtained when the temperature is raised. In the measurement, alumina is used as a reference material. In addition, as a differential scanning calorimeter apparatus, the differential scanning calorimeter apparatus marketed by the SII nanotechnology company by the brand name "DSC6220 type | mold" can be used, for example.

  By heating the laminate M, the fiber reinforcement 2 is in a state where it can be pressed with the reinforcing synthetic resin impregnated therein having fluidity, and the foamed sheet 1 is also softened by heating. It can be easily formed by press forming.

  In this state, as shown in FIGS. 4 and 5, the laminate M is disposed between the male and female molds 41 and 42, and the male and female molds 41 and 42 are clamped to form a laminate by press molding. The foam sheet 1 of the body M is formed into a desired shape, and the fiber reinforcement 2 is formed into a desired shape while sliding on the foam sheet 1. During press molding, the temperature of the male and female molds is controlled so that the reinforcing synthetic resin of the fiber reinforcement 2 maintains fluidity. At the time of press molding, the laminate M is pressed by the male and female dies 41 and 42, so that the reinforcing synthetic resin contained in the fiber reinforcement 2 oozes out on the surface of the fiber reinforcement 2 and the fiber reinforcement 2. Thus, the surface of the resulting fiber reinforced composite A is formed on a smooth surface where the fibers of the fiber reinforcing material are not exposed.

  In addition, when the foam sheet 1 of the laminated body M and the fiber reinforcing material 2 are temporarily bonded, the fiber reinforcing material 2 and the foamed sheet 1 are pressed during the press molding of the laminated body M due to heating of the laminated body M or other stress. The fiber reinforcing material 2 is freely slid and movable on the foam sheet 1. Further, in the male and female dies 41 and 42, the surface contacting the laminated body M is subjected to a mold release treatment so that the fiber reinforced composite A obtained by press-molding the laminated body M can be easily taken out from the mold. It may be given.

  Although the case where the laminated body M is heated and disposed between the male and female molds 41 and 42 has been described above, the laminated body M is disposed between the male and female molds 41 and 42 and then the laminated body M is disposed. You may heat.

  The foamed sheet 1 may be stretched during the press molding of the laminate M, and the thickness may be partially or entirely reduced. Therefore, it is preferable that the foamed sheet 1 of the laminate M is subjected to secondary foaming during press molding. By subjecting the foam sheet 1 of the laminate M to secondary foaming, the foam sheet 1 of the resulting fiber reinforced composite is prevented from being thinned, and a desired thickness and impact absorbability are imparted to the fiber reinforced composite. Can do.

  Furthermore, the fiber reinforcement 2 can be strongly pressed against the male and female molds 41 and 42 by secondary foaming of the foam sheet 1 during the press molding of the laminate M, and the fiber reinforcement 2 can be pressed against the male and female molds 41, 42. While being able to shape | mold correctly along 42, the fiber reinforcement 2 can be laminated | stacked on the surface of the foam sheet 1 in the state closely_contact | adhered so that there may be no clearance gap between both.

  In addition, the foam sheet 1 itself can strongly press the foam sheet 1 against the male and female molds 41 and 42 by its secondary foaming force, and the foam sheet 1 is accurately molded along the male and female molds 41 and 42. The fiber reinforced composite A having a desired shape can be easily manufactured.

  Further, when the foamed sheet 1 contains a crystalline resin during the press molding of the laminated body M and in a curing step which will be described later, the fiber obtained by increasing the crystallinity of the crystalline resin. It is preferable to improve the heat resistance and mechanical strength of the reinforced composite.

  Next, after the laminated body M is press-molded by male and female dies 41 and 42 and formed into a desired shape, the fiber reinforced material 2 is impregnated with an uncured thermosetting resin. The uncured thermosetting resin contained in the fiber reinforcing material 2 is cured, and the fibers of the fiber reinforcing material are bound and fixed with a cured thermosetting resin to fix the fiber reinforcing material 2 to the fiber reinforced composite material. The fiber reinforced composite material A1 is laminated and integrated on at least one surface of the foamed sheet 1 with a thermosetting resin obtained by curing the fiber reinforced composite material A1 to produce a fiber reinforced composite A (curing step).

  The heating temperature for curing the uncured thermosetting resin contained in the fiber reinforcement 2 of the laminate M may be the same as or changed from the heating temperature of the laminate M during press molding. However, it is preferable to increase the heating temperature of the laminate M in order to promote the curing of the thermosetting resin.

  If the heating temperature for curing the uncured thermosetting resin contained in the fiber reinforcement 2 of the laminate M is too low, curing of the thermosetting resin becomes insufficient, resulting in fiber reinforcement obtained. The mechanical strength of the composite may be reduced, and if it is too high, the bubbles of the foamed sheet may be destroyed by heat, and the resulting fiber-reinforced composite may be reduced in lightness and impact absorption. The glass transition temperature of the thermosetting resin—50 ° C.) to (the glass transition temperature of the thermosetting resin + 50 ° C.) is preferred, and the glass transition temperature of the thermosetting resin—40 ° C.— (Temperature + 40 ° C.) is more preferable. When two or more types of thermosetting resins are contained in the reinforcing synthetic resin, the glass transition temperature of the thermosetting resin is the glass transition temperature of the thermosetting resin contained in the reinforcing synthetic resin. The glass transition temperature Tg is the highest.

  Further, when the reinforcing synthetic resin impregnated in the fiber reinforcement 2 is a thermoplastic resin, unlike the case of the thermosetting resin, the above-described curing step is not necessary, and the thermoplastic resin is cooled by cooling as described later. After the tree is solidified, the fibers of the fiber reinforced material are bound and fixed with a solidified thermoplastic resin, and the fiber reinforced material 2 is made into a fiber reinforced composite material A1, and this fiber reinforced composite material A1 is solidified by the thermoplastic resin. The fiber reinforced composite A is manufactured by laminating and integrating on at least one surface of the foam sheet 1.

  Next, after the fiber reinforced composite A is cooled as necessary, the male and female molds 41 and 42 are opened to take out the fiber reinforced composite A to obtain the fiber reinforced composite A (see FIG. 6). The obtained fiber reinforced composite A has a fiber reinforced composite material A1 in which fibers are bound together by a thermoplastic resin or a cured thermosetting resin and formed into a desired shape along the male and female molds 41 and 42. The sheets are laminated and integrated so as to be in close contact with the entire surface of the sheet 1. Although FIG. 6 shows a state in which the release film 3 is laminated on the fiber reinforced composite material A1, the release film 3 is easily peeled off and removed from the fiber reinforced material A1 of the fiber reinforced composite material A. can do. Moreover, in FIG. 6, the foam sheet 1 showed the state which cut off the both ends.

  The fiber reinforced composite A thus obtained has a strong fiber reinforced composite A1 in which the fibers are firmly bound to each other on the surface of the foamed sheet 1 with a thermoplastic resin or a cured thermosetting resin. It is laminated and integrated, has an excellent mechanical strength, and also has a lightweight and shock absorbing property because it has a foam in part.

  If the crystallinity of the foam sheet 1 of the fiber reinforced composite A is too low, the mechanical strength or heat resistance of the fiber reinforced composite may be lowered. If it is too high, the fiber reinforced composite becomes brittle and easily cracked. When the unnecessary portion of the fiber reinforced composite is excised, cracks may occur in the fiber reinforced composite, so 10 to 35% is preferable, and 15 to 30% is more preferable.

  As described above, the method for producing a fiber-reinforced composite of the present invention grips the foam sheet without gripping the fiber reinforcement and press-molds it with a male and female mold. It can be accurately molded along the mold.

  The fiber reinforced composite obtained by the method for producing a fiber reinforced composite of the present invention has excellent mechanical strength because it has a fiber reinforced composite on its surface, and partly foamed. Since it has a sheet, it has excellent light weight and shock absorption.

  Furthermore, in the method for producing a fiber reinforced composite, when the foamed sheet is subjected to secondary foaming during press molding, the thickness of the foamed sheet can be sufficiently secured in the obtained fiber reinforced composite, and the fiber reinforced The composite has better lightness and shock absorption. Furthermore, the secondary foaming force of the foamed sheet during press molding allows the fiber reinforcing material and the foamed sheet to be pressed firmly against the male and female molds to accurately form the desired shape, and the fiber reinforcing material and the foamed sheet Thus, a fiber reinforced composite comprising a fiber reinforced composite material laminated and integrated more firmly on at least one surface of the foamed sheet can be easily obtained.

It is the figure which showed the orientation of the fiber which comprises the fiber reinforcement. It is the figure which showed the orientation of the fiber which comprises the fiber reinforcement. It is the schematic diagram which showed an example of the state which cut | notched the fiber reinforcement material. It is the schematic diagram which showed the state which has arrange | positioned the laminated body between the male and female metal mold | die. It is the schematic diagram which showed the state which is press-molding the laminated body with the male and female metal mold | die. It is the schematic diagram which showed the state which opened the male and female metal mold | die, took out the fiber reinforced composite, and cut off the both ends of the foam sheet. It is the top view which showed the fiber reinforced composite_body | complex obtained in the Example. It is sectional drawing which showed the fiber reinforced composite_body | complex obtained in the Example.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

Example 1
100 parts by weight of polyethylene terephthalate (PET, trade name “SA-135” manufactured by Mitsui Chemicals, glass transition temperature: 79 ° C., melting point: 247.1 ° C., IV value: 0.86), 0.72 parts by weight of talc, and The thermoplastic polyester resin composition containing 0.2 parts by weight of pyromellitic anhydride was supplied to a single screw extruder having a diameter of 65 mm and an L / D ratio of 35, and melt kneaded at 290 ° C.

  Next, from the middle of the extruder, a thermoplastic polyester resin composition in a molten state so that butane containing 35% by weight of isobutane and 65% by weight of normal butane is 1.0 part by weight with respect to 100 parts by weight of polyethylene terephthalate. And was uniformly dispersed in the thermoplastic polyester resin composition.

  Thereafter, the thermoplastic polyester resin composition in a molten state is cooled to 220 ° C. at the front end portion of the extruder, and then extruded and foamed into a cylindrical shape from a circular die attached to the front end of the extruder to produce a cylindrical body. The cylindrical body is gradually expanded in diameter and then supplied to the cooling mandrel to be cooled, and then the cylindrical body is continuously cut in the extruding direction between the inner and outer peripheral surfaces, opened, and opened. A polyethylene terephthalate foam sheet was produced. A polyethylene terephthalate foam sheet was cut into a plane square shape with a side of 350 mm. Table 1 shows the expansion ratio, thickness, basis weight, heating thickness expansion coefficient, crystallinity, and residual gas amount of the polyethylene terephthalate foam sheet.

Next, two sheets of face material (trade name “Pyrofil Prepreg TR3523-395GMP” manufactured by Mitsubishi Rayon Co., Ltd., basis weight: 200 g / m ² , thickness: 0.23 mm) formed from a twill weave made of carbon fiber are prepared. did. The face material had a planar square shape with a side of 250 mm. The face material contained 40% by weight of an uncured epoxy resin (glass transition temperature: 121 ° C.) as a thermosetting resin.

  Two face materials were overlapped so that the warp yarns were 90 ° in length direction to form a multilayer face material. The face materials were integrated with an epoxy resin contained in the face material. One more multi-layer face material was produced in the same manner.

A multilayer face material is laminated on both sides of the polyethylene terephthalate foamed sheet 1 as a fiber reinforcement 2 and crimped using a crimping instrument (trade name “Share Shot Iron SI-39S” manufactured by Ishizaki Electric Manufacturing Co., Ltd., instrument weight 860 g). The bonding surface temperature of the device is 18 ± 3 ° C., and is bonded with the weight of the crimping device alone (559 ± 196 Pa (5.7 ± ² gf / cm ² )). A reinforcing material is temporarily bonded to both surfaces of the polyethylene terephthalate foam sheet 1, and then a release film 3 (trade name “Oydis” manufactured by Kurabo Industries, special polystyrene-based resin film, thickness 50 μm) is laminated on the fiber reinforcing material 2. Thus, the laminate M was manufactured (lamination process). Table 1 shows the temporary adhesive force between the polyethylene terephthalate foam sheet 1 and the fiber reinforcement 2.

  Next, the polyethylene terephthalate foam sheet 1 of the laminate M was gripped by using clamps at the edges of the two opposite sides, while the fiber reinforcement 2 was not gripped at all. Thereafter, the laminate M is heated for 5 seconds so that the surface temperature of the fiber reinforcement 2 becomes 150 ° C., and the uncured epoxy resin impregnated in the fiber reinforcement 2 is softened and cured. It was set as the state which has fluidity. In this state, the temporary adhesion between the foam sheet 1 and the fiber reinforcement 2 was completely released, and the fiber reinforcement 2 was in a state of being freely movable on the foam sheet 1.

  Subsequently, as shown in FIGS. 4 and 5, the laminated body M is disposed between the male and female molds 41 and 42, and the male and female molds 41 and 42 are clamped to form a laminated body. The foamed sheet 1 of M was formed into a desired shape, and the fiber reinforcement 2 was formed into a desired shape while sliding on the foamed sheet 1. At the time of press molding, the surface temperature of the fiber reinforcing material 2 of the laminate M was maintained at 140 ° C., and the epoxy resin contained in the fiber reinforcing material 2 was controlled to maintain fluidity without being cured. .

  At the time of press molding, the foamed sheet 1 of the laminate M was subjected to secondary foaming and the crystallinity of polyethylene terephthalate constituting the foamed sheet was increased.

  Next, the laminate M is heated for 5 minutes so that the surface temperature of the fiber reinforcement 2 is 140 ° C., and the uncured epoxy resin contained in the fiber reinforcement 2 is cured, The fibers of the fiber reinforced material are bonded and fixed with a cured epoxy resin, and the fiber reinforced material 2 is made into a fiber reinforced composite material A1, and the fiber reinforced composite material A1 is laminated on both sides of the foam sheet 1 with the cured epoxy resin. To produce a fiber-reinforced composite A (curing step).

  Thereafter, the fiber reinforced composite A is cooled until the surface temperature of the fiber reinforced composite A1 becomes 30 ° C. or lower, and then the male and female molds 41 and 42 are opened to take out the fiber reinforced composite A and take out the fiber reinforced composite. A was obtained. The obtained fiber reinforced composite A has a fiber reinforced composite material A1 in which fibers are bound by a cured thermosetting resin and formed into a desired shape along male and female molds 41 and 42. Are laminated and integrated so as to be in close contact with each other. The plane part and sectional drawing of the fiber reinforced composite A are shown in FIGS. In FIGS. 7 and 8, the layer configuration is omitted.

(Example 2)
A fiber-reinforced composite A was obtained in the same manner as in Example 1 except that butane was press-fitted from the middle of the extruder so as to be 0.6 parts by weight with respect to 100 parts by weight of polyethylene terephthalate.

(Example 3)
Instead of the thermoplastic polyester resin composition, a mixture of polyphenylene ether and polystyrene resin (trade name “NORYL NLV025-111” manufactured by GE Plastics Co., Ltd., polyphenylene ether amount: 70 wt%, polystyrene resin amount: 30 wt. %) 51.7% by weight and polystyrene (trade name “HRM-26” manufactured by Toyo Styrene Co., Ltd.) 42.9% by weight, modified polyphenylene ether resin (phenylene ether (PPE) component: 40% by weight, styrene (PS) Ingredient: 60% by weight) A modified polyphenylene ether-based resin composition containing 100 parts by weight and 0.55 parts by weight of powdered talc was supplied to a single screw extruder, and butane was added to 100 parts by weight of polyethylene terephthalate from the middle of the extruder. And press-fitted to 0.7 parts by weight. To produce a polyphenylene ether-based resin foam sheet, to obtain a fiber-reinforced composite A in the same manner as in Example 1 except for using, instead of the modified polyphenylene ether-based resin foam sheet of polyethylene terephthalate foamed sheet. In Table 1, the modified polyphenylene ether resin is represented as “modified PPE”.

Example 4
A fiber reinforcing material is temporarily bonded to one surface of the polyethylene terephthalate foam sheet 1 using a crimping device (KAISEL Co., Ltd., trade name “urethane roller”, device weight 155 g), and the temporary adhesive force between the polyethylene terephthalate foam sheet and the fiber reinforcing material is expressed. A fiber-reinforced composite A was obtained in the same manner as in Example 1 except that it was as shown in FIG.

(Example 5)
A fiber reinforced composite A was obtained in the same manner as in Example 1 except that a polyethylene terephthalate foamed sheet having the same configuration as in Example 1 was used except that it had a residual gas amount as shown in Table 1. .

(Example 6)
The crimping surface temperature of the crimping device is 45 ± 5 ° C., and the fiber reinforcing material is temporarily bonded to one surface of the polyethylene terephthalate foamed sheet 1, and the temporary adhesive force between the polyethylene terephthalate foamed sheet and the fiber reinforcing material is as shown in Table 1. A fiber-reinforced composite A was obtained in the same manner as in Example 1 except that it was present.

(Example 7)
A polyethylene terephthalate foam sheet was produced in the same manner as in Example 2. Next, a face material (trade name “NNGF60-03s” manufactured by Nagase Chemtech Co., Ltd.) made of satin weave made of glass fiber (trade name “WE181D” manufactured by Nitto Boseki Co., Ltd.), basis weight: 300 g / m ² , thickness: Two sheets of 0.3 mm) were prepared. The face material had a planar square shape with a side of 250 mm. The face material contained 40% by weight of a thermoplastic epoxy resin (glass transition temperature: 97 ° C.).

  Two face materials were overlapped so that the warp yarns were 90 ° in length direction to form a multilayer face material. The face materials were integrated with a thermoplastic epoxy resin contained in the face material. One more multi-layer face material was produced in the same manner.

A multilayer face material is laminated as a fiber reinforcing material 2 on each of both surfaces of the polyethylene terephthalate foam sheet 1, and a crimping instrument (trade name “Share Shot Iron SI-39S” manufactured by Ishizaki Electric Manufacturing Co., Ltd., instrument weight 860 g) is used. The temperature of the crimping surface of the crimping device is 100 ° C., and it is crimped with the weight of the crimping device alone (559 ± 196 Pa (5.7 ± ² gf / cm ² )), and the thermoplastic epoxy resin contained in the fiber reinforcement The fiber reinforcement 2 is temporarily bonded to both surfaces of the polyethylene terephthalate foamed sheet 1, and then the release film 3 (trade name “Oydis” manufactured by Kurabo Industries, special polystyrene resin film, thickness 50 μm) is attached to the fiber reinforcement 2 A laminate M was manufactured by laminating the laminate (lamination step). Table 1 shows the temporary adhesive force between the polyethylene terephthalate foam sheet 1 and the fiber reinforcement 2.

  Next, the polyethylene terephthalate foam sheet 1 of the laminate M was gripped by using clamps at the edges of the two opposite sides, while the fiber reinforcement 2 was not gripped at all. Thereafter, the laminate M is heated for 30 seconds so that the surface temperature of the fiber reinforcing material 2 becomes 150 ° C., and the thermoplastic epoxy resin impregnated in the fiber reinforcing material 2 is softened to improve the fluidity. It was in a state of having. In this state, the temporary adhesion between the foam sheet 1 and the fiber reinforcement 2 was completely released, and the fiber reinforcement 2 was in a state of being freely movable on the foam sheet 1.

  Subsequently, as shown in FIGS. 4 and 5, the laminated body M is disposed between the male and female molds 41 and 42, and the male and female molds 41 and 42 are clamped to form a laminated body. The foamed sheet 1 of M was formed into a desired shape, and the fiber reinforcement 2 was formed into a desired shape while sliding on the foamed sheet 1. At the time of press molding, the surface temperature of the fiber reinforcement 2 of the laminate M was maintained at 110 ° C., and the thermoplastic epoxy resin contained in the fiber reinforcement 2 was controlled to maintain fluidity.

  At the time of press molding, the foamed sheet 1 of the laminate M was subjected to secondary foaming and the crystallinity of polyethylene terephthalate constituting the foamed sheet was increased.

  Next, after the laminated body M is cooled until the surface temperature of the fiber reinforcing material 2 becomes 30 ° C. or less, the male and female molds 41 and 42 are opened, and the fiber reinforced composite A is taken out to obtain the fiber reinforced composite A. It was. The obtained fiber reinforced composite A is composed of a fiber reinforced composite material A1 in which fibers are bound and fixed by a thermoplastic epoxy resin and formed into a desired shape along male and female molds 41 and 42. Thus, the foamed sheet 1 was laminated and integrated so as to be in close contact with both surfaces of the foam sheet 1 along their surfaces. The plane part and sectional drawing of the fiber reinforced composite A are shown in FIGS. In FIGS. 7 and 8, the layer configuration is omitted.

(Example 8)
A fiber-reinforced composite A was obtained in the same manner as in Example 7, except that the modified polyphenylene ether-based resin foam sheet produced in Example 3 was used instead of the polyethylene terephthalate foam sheet.

(Comparative Example 1)
While trying to manufacture a fiber reinforced composite in the same manner as in Example 1 except that both the foam sheet and the fiber reinforcement were clamped during press molding, the fiber reinforcement could not be press molded and the fiber A reinforced composite could not be obtained.

(Comparative Example 2)
While trying to produce a fiber reinforced composite in the same manner as in Example 3 except that both the foam sheet and the fiber reinforcement were clamped during press molding, the fiber reinforcement could not be press molded and the fiber A reinforced composite could not be obtained.

(Comparative Example 3)
A polyethylene terephthalate foam sheet was produced in the same manner as in Example 1, and this polyethylene terephthalate foam sheet was used. Except that both the foam sheet and the fiber reinforcement were clamped during press molding, the same as in Example 7. An attempt was made to produce a fiber reinforced composite, but the fiber reinforced material could not be press molded and a fiber reinforced composite could not be obtained.

  The thickness variation, deep drawability and appearance of the obtained fiber reinforced composite A were measured as described below, and the crystallinity of the foamed sheet was measured as described above. The results are shown in Table 1.

(Thickness variation)
The thickness of the (a)-(d) part of the fiber reinforced composite A shown in FIG. 7 was measured. (A) ~ the maximum difference (d) portion of the thickness as T _1, the arithmetic mean value of (a) ~ (d) portion of the thickness was set to T _2. The thickness variation was calculated based on the following formula. In the (a) to (d) portions of the fiber reinforced composite A, the fiber reinforced composite materials A1 and A1 were laminated and integrated on both surfaces of the foamed sheet 1.
Thickness variation (%) = 100 × T ₁ / T ₂

(Deep drawability)
As an index as to whether or not the shape shown in FIG. 7 can be accurately formed, the height (mm) of the (b) and (c) portions of the fiber reinforced composite A in FIG. The average value was used as an index of deep drawability. For measurement, the fiber reinforced composite A is placed on a flat placement surface such that the end in the length direction is in contact with the placement surface and the portions (b) and (c) are in a state of floating from the placement surface. Then, the height of the portions (b) and (c) from the mounting surface was measured using a caliper. In the design of the mold, the heights of the parts (b) and (c) of the fiber reinforced composite A are set to 10 mm. Therefore, the height of the fiber reinforced composite A with good deep drawing takes into account the molding shrinkage rate. Is also 10 mm. The arithmetic average value of the heights of the (b) and (c) portions is preferably 6 to 10 mm, and more preferably 7 to 10 mm. If it is outside these ranges, it can be determined that the deep drawability is poor.

(appearance)
The appearance of the obtained fiber reinforced composite A was visually observed and evaluated based on the following criteria.
○: There were 2 or less linear or spotted recesses formed on the fiber reinforced composite due to wrinkles or air pockets.
Δ: 3 or 4 linear or spotted recesses formed by wrinkles or air pockets formed in the fiber reinforced composite.
X: Five or more linear or spotted recesses formed on the fiber reinforced composite due to wrinkles or air pockets were generated.

DESCRIPTION OF SYMBOLS 1 Foam sheet 2 Fiber reinforcement 3 Release film 5 Clamp
41, 42 Male and female mold A Fiber reinforced composite
A1 Fiber reinforced composite material M Laminate

Claims (6)

A laminating step in which a laminate is manufactured by laminating at least one surface of a foamed sheet with a face material-like fiber reinforcing material impregnated with a thermoplastic resin or an uncured thermosetting resin , and the fiber is obtained by heating the laminate. After the thermoplastic resin impregnated in the reinforcing material or the uncured thermosetting resin is softened to have a fluid state, the foam sheet is gripped without gripping the fiber reinforcing material of the laminate. And a molding step of forming the laminate by press molding the laminate with a male and female mold. The fiber reinforcing material is impregnated with an uncured thermosetting resin, and further includes a curing step performed after the molding step and curing the thermosetting resin contained in the fiber reinforcing material of the laminate. The method for producing a fiber-reinforced composite according to claim 1. Lamination process for producing a laminate by laminating a fiber reinforcement material impregnated with a thermoplastic resin or an uncured thermosetting resin on at least one surface of the foam sheet, and heating the laminate to impregnate the fiber reinforcement After the softened thermoplastic resin or uncured thermosetting resin is softened to have a fluid state, the laminate is held in a state where the foamed sheet is held without holding the fiber reinforcement of the laminate. And a molding step of molding the laminate by press molding with a male and female mold, and in the molding step, a foamed sheet is secondarily foamed . The method for producing a fiber-reinforced composite according to claim 3 , wherein the foam sheet has a thickness expansion coefficient of 0.5% or more for 1 minute at 150 ° C. The method for producing a fiber-reinforced composite according to any one of claims 1 to 4, wherein a fiber reinforcing material is temporarily bonded to one surface of the foam sheet. The method for producing a fiber-reinforced composite according to any one of claims 1 to 5, wherein the laminate is formed after a release film is laminated on the fiber reinforcement of the laminate.

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