JP6151962B2 - Fiber reinforced composite - Google Patents

Description

  The present invention relates to a fiber reinforced composite.

  From the viewpoint of energy saving, in recent years, in the fields of automobiles, aircraft, railway vehicles, etc., instead of metal materials that are inferior in weight, high strength materials such as fiber reinforced plastics and lightweight core materials such as synthetic resin foam sheets are used. The use of fiber reinforced composites that are made into composites is becoming stronger, and it is intended to produce a fiber reinforced composite that is lightweight and has excellent shock absorption and mechanical strength obtained by foaming a thermoplastic resin. Has been.

  Patent Document 1 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 disposed on both surfaces of the core material. The reinforcing fibers include reinforcing fibers having a tensile elastic modulus in the range of 200 to 850 GPa, and the reinforcing fiber content in the skin material is in the range of 40 to 80% by weight, and the core material includes polypropylene or polymethacrylimide A fiber reinforced fiber having a total thickness of a sandwich panel in which a laminate comprising the core material and the skin material is simultaneously heated and pressurized is within a range of 0.5 to 5 mm. A resin sandwich panel is disclosed.

  Patent Document 1 exemplifies the thermoplastic resin used for the core material in paragraph [0019], but merely lists general-purpose thermoplastic resins, and in the examples, a polypropylene foam sheet or A polymethacrylimide foam sheet is used.

  However, the polypropylene foam sheet has insufficient heat resistance, has low adhesion to the matrix resin contained in the skin material, and has a problem that the impact resistance of the fiber reinforced composite is low. Since the methacrylimide foam sheet has high brittleness, it has a problem that the impact resistance of the fiber-reinforced composite is low.

JP 2005-313613 A

  The present invention provides a fiber reinforced composite excellent in heat resistance and impact resistance.

  The fiber reinforced composite A of the present invention has a synthetic resin foam sheet 1 having an average cell diameter of 10 to 400 μm and a contact angle of 30 to 90 °, and a fiber reinforcement laminated and integrated on the surface of the synthetic resin foam sheet. And a plastic layer 2.

  The synthetic resin constituting the synthetic resin foam sheet 1 is not particularly limited, and examples thereof include polycarbonate resin, modified polyphenylene ether resin, polystyrene resin, polyamide resin, and thermoplastic polyester resin. In addition, a synthetic resin may be used independently or 2 or more types may be used together.

  Examples of the polycarbonate resin include polymers obtained by a phosgene method in which a dihydroxydiaryl compound and phosgene are reacted, and a transesterification method in which a dihydroxydiaryl compound and a carbonate such as diphenyl carbonate are reacted. Is a polycarbonate resin produced from 2,2-bis (4-hydroxyphenyl) propane (bisphenol A).

  Examples of the dihydroxydiaryl compound include bisphenol 4-, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2, 2-bis (4-hydroxyphenyl) octane, bis (4-hydroxyphenyl) phenylmethane, 2,2-bis (4-hydroxyphenyl-3-methylphenyl) propane, 1,1-bis (4-hydroxy-3) -Tert-butylphenyl) propane, 2,2-bis (4-hydroxy-3-bromophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxy-3,5-dichlorophenyl) propane, 1,1- (4-hydroxyphenyl) cyclopentane, bis (hydroxyaryl) cycloalkanes such as 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3 Dihydroxy diaryl ethers such as 3,3'-dimethyldiphenyl ether, dihydroxy diaryl sulfides such as 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'- Dihydroxydiaryl sulfoxides such as dimethyldiphenyl sulfoxide, dihydroxydiaryls such as 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone Such as sulfonic acids and the like.

  Examples of the modified polyphenylene ether resin include a mixture of polyphenylene ether and a polystyrene resin, a modified polyphenylene ether obtained by graft copolymerization of a styrene monomer with polyphenylene ether, a mixture of this modified polyphenylene ether and a polystyrene resin, and phenol. And a block copolymer obtained by oxidative polymerization of a styrene monomer and a styrene monomer in the presence of a catalyst such as an amine complex of copper (II), and a mixture of the block copolymer and a polystyrene resin. The modified polyphenylene ether resins may be used alone or in combination of two or more.

  Examples of the polyamide resin include nylon 6, nylon 6,6, nylon 10, nylon 11, nylon 12, nylon 6,12, nylon 12,12, nylon 4,6, and the like. Polyamide resins may be used alone or in combination of two or more. The polyamide resin is produced, for example, by polycondensation of diamine, dicarboxylic acid, ω-amino-ω ′ carboxylic acid, or ring-opening polymerization of cyclic lactam.

  Examples of the diamine include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, and 1,10-diamino. Examples include decane, phenylenediamine, and metaxylylenediamine.

  Examples of the dicarboxylic acid include glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, tetradecanedicarboxylic acid, octadecanedicarboxylic acid, fumaric acid, phthalic acid, xylylene diene Examples thereof include carboxylic acid.

  Examples of the ω-amino-ω ′ carboxylic acid include 6-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid.

  Examples of the cyclic lactam include ε-caprolactam, ω-enantolactam, and ω-lauryl lactam.

  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.

  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 small, the melt viscosity at the time of melting of polyethylene terephthalate may be too small and bubble breakage may occur. When the synthetic resin foam sheet is produced by extrusion foaming, extrusion foaming may be difficult, so 0.01 to 5 parts by weight is preferable with respect to 100 parts by weight of polyethylene terephthalate. 1 part by weight is more preferred.

  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. The aromatic polyester resin may be mixed with a PCT resin (polycyclohexylene dimethylene terephthalate) or the like.

  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 particles, D-lactic acid (D-form) and One or more 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 A ring-opening polymer of lactide 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.

  The synthetic resin foam sheet 1 has an average cell diameter limited to 10 to 400 μm, preferably 100 to 300 μm, and more preferably 150 to 200 μm. This is because, when an impact force is applied to the fiber reinforced composite A, a part of the bubble wall of the synthetic resin foam sheet 1 is destroyed by the impact force, and the destruction of the bubble wall propagates to the adjacent bubble walls one after another. May occur. At this time, if the average cell diameter of the synthetic resin foam sheet is too large, the number of bubbles present in the synthetic resin foam sheet decreases. When an impact force is applied to the synthetic resin foam sheet and some of the cell walls are destroyed, as described above, the destruction of the cell walls propagates to the adjacent cell walls one after another, and the number of cells is small. The destruction of the wall tends to reach the interface between the synthetic resin foam sheet and the fiber reinforced plastic layer described later. When the bubble wall of the synthetic resin foam sheet reaches the interface between the synthetic resin foam sheet and the fiber reinforced plastic layer, the surface of the synthetic resin foam sheet is destroyed. The integration is broken, and the fiber reinforced plastic layer is peeled off from the surface of the synthetic resin foam sheet, causing a problem that the impact resistance of the fiber reinforced composite is lowered.

  On the other hand, if the average cell diameter of the synthetic resin foam sheet 1 is too small, the number of air bubbles contained in the synthetic resin foam sheet becomes too large, and the thickness of the cell walls becomes too thin. The bubble wall is easily broken by the impact force, and the breakage of the bubble wall easily reaches the interface between the synthetic resin foam sheet and the fiber reinforced plastic layer described later. As a result, for the same reason as described above, the fiber reinforced plastic layer is peeled off from the surface of the synthetic resin foam sheet, causing a problem that the impact resistance of the fiber reinforced composite is lowered.

  The average cell diameter of the synthetic resin foam sheet 1 was measured by the following test method. As shown in FIG. 1, the synthetic resin foam sheet is cut at a plane α along the MD direction (extrusion direction) and perpendicular to the foam sheet surface at the center in the width direction, and the cut surface is scanned with a scanning electron microscope. The photograph is magnified 18 to 20 times (200 times in some cases) to obtain an enlarged photograph A. Note that the size of the enlarged photograph A is about ¼ of the size of A4.

  The synthetic resin foam sheet is cut along a plane β along the TD direction (width direction) and perpendicular to the foam sheet surface, and the cut surface is enlarged 18 to 20 times (in some cases 200 times) with a scanning electron microscope. To obtain an enlarged photo B. Note that the size of the enlarged photograph B is about 1/4 of the size of A4.

  The synthetic resin foam sheet is cut by a plane γ orthogonal to the MD direction and the TD direction, and the cut surface is enlarged and photographed with a scanning electron microscope 18 to 20 times (in some cases 200 times) to obtain an enlarged photograph C. . Note that the size of the enlarged photo C is about 1/4 of the size of A4.

  When a 60 mm straight line is drawn on the printed photograph, the magnification of the scanning electron microscope is adjusted so that the number of bubbles present on the straight line is about 10 to 20.

  The enlarged photographs A to C are taken at two arbitrary positions of the synthetic resin foam sheet, and two enlarged pictures A to C are obtained.

  In addition, as a scanning electron microscope, the scanning electron microscope marketed with the brand name "S-3000N" from Hitachi, Ltd., and the scanning marketed with the brand name "S-3400N" from Hitachi High-Technologies Corporation. A type electron microscope can be used.

In the enlarged photograph A, a straight line with a length of 60 mm parallel to each of the MD direction and the VD direction (direction orthogonal to the MD direction on the photograph) is drawn at an arbitrary position, and each of the bubbles is determined from the number of bubbles on the straight line. The average chord length (t) in the direction is calculated by the following formula. However, when the thickness of the test piece is thin and the number of bubbles of 60 mm length cannot be counted in the VD direction (sheet thickness direction), the number of bubbles of 30 mm or 20 mm is counted and converted to the number of bubbles of 60 mm. . The straight line was drawn so that the entire bubble was on the straight line as much as possible. Bubbles that are only partially on a straight line are also included in the number of bubbles as one.
Average chord length t (mm) = 60 / (number of bubbles × photo magnification)

  In the enlarged photograph B, a straight line with a length of 60 mm parallel to each of the TD direction and the VD direction (direction orthogonal to the TD direction on the photograph) is drawn at an arbitrary position, and each of the bubbles is determined from the number of bubbles on the straight line. The average chord length (t) in the direction is calculated by the above formula.

  In the enlarged photograph C, a straight line with a length of 60 mm parallel to each of the MD direction and the TD direction is drawn at an arbitrary location, and the average chord length (t) in each direction of the bubble is calculated from the number of bubbles on the straight line by the above formula. Calculated by

The magnification of the photograph is obtained by the following equation by measuring the scale bar on the photograph to 1/100 mm. In addition, as a scale bar, what is marketed with the brand name "Digimatic Caliper" from Mitutoyo Corporation can be used, for example.
Magnification factor of photograph = Scale bar actual measurement value (mm) / Scale bar display value (mm)

And the bubble diameter in each direction was computed by following Formula.
D (mm) = t / 0.616

Based on the obtained bubble diameter in the MD direction (D _MD ), bubble diameter in the TD direction (D _TD ), and bubble diameter in the VD direction (D _VD ), the average bubble diameter of the synthetic resin foam sheet is calculated by the following formula. Incidentally, the bubble diameter D _MD in the MD direction is the arithmetic mean value of the cell diameters of the two MD direction calculated above. The bubble diameter D _TD in the TD direction is an arithmetic average value of the two calculated bubble diameters in the TD direction. The bubble diameter D _VD in the VD direction is an arithmetic average value of the calculated bubble diameters in the two VD directions.
Average bubble diameter (mm) = (D _MD × D _TD × D _VD ) ^1/3
D _MD : Bubble diameter in the MD direction (mm)
D _TD : Bubble diameter in TD direction (mm)
D _VD : Bubble diameter in the VD direction (mm)

  If the thickness of the synthetic resin foam sheet constituting the fiber reinforced composite is too thin, the impact resistance of the fiber reinforced composite may be reduced. If it is too thick, the impact force applied to the fiber reinforced composite may decrease. Since the synthetic resin foam sheet is greatly deformed and cracks are generated in the fiber reinforced plastic layer, and the impact resistance of the fiber reinforced composite may be lowered, 0.1 to 5 mm is preferable, and 0.3 to 4 mm is more preferable. .

  The tensile elongation at break of the synthetic resin foam sheet constituting the fiber reinforced composite is preferably 5 to 30%, more preferably 5 to 25%, and particularly preferably 5 to 20%. If the tensile elongation at break of the synthetic resin foamed sheet is too low, the brittleness of the synthetic resin foamed sheet increases, and the impact force applied to the fiber reinforced composite breaks the synthetic resin foamed sheet and the impact resistance of the fiber reinforced composite May decrease. If the tensile elongation at break of the synthetic resin foamed sheet is too high, the synthetic resin foamed sheet is greatly deformed by the impact force applied to the fiber reinforced composite, resulting in cracks in the fiber reinforced plastic layer and the resistance of the fiber reinforced composite. Impact properties may be reduced.

  The tensile elongation at break of the synthetic resin foam sheet was measured in accordance with the method described in JIS K6767: 1999 “Foamed Plastics—Polyethylene Test Method”. Specifically, after holding the test piece in an environment of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5% for 16 hours or more, the test piece is placed in an environment of a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%. And measure. Using a Tensilon universal testing machine and universal testing machine data processing software, measurement is performed under conditions of a tensile speed of 500 mm / min, a gripping tool spacing of 100 mm, and a dumbbell type 1 (ISO 1798: 2008 standard). However, the elongation was defined as the difference between the distance between the grips before the test and the distance between the grips when the test piece was cut. Five test pieces are prepared, and the arithmetic average value of the elongation at break of each test piece is taken as the elongation at break of the synthetic resin foam sheet. In addition, as a tensilon universal testing machine, the testing machine marketed by the brand name "UCT-10T" from Orientec can be used, for example. As the data processing software, for example, software commercially available from SoftBrain under the trade name “UTPS-237S” can be used.

  If the contact angle of the synthetic resin foam sheet is too small, an excessive amount of the reinforcing synthetic resin in the fiber reinforced plastic layer moves to the synthetic resin foam sheet side, and the mechanical strength of the fiber reinforced plastic layer decreases, As a result, the mechanical strength such as impact resistance of the fiber reinforced composite decreases, and if it is too large, the adhesion between the reinforcing synthetic resin and the synthetic resin foam sheet contained in the fiber reinforced plastic layer decreases, When an impact force is applied to the fiber reinforced composite, the fiber reinforced plastic layer is peeled off from the surface of the synthetic resin foam sheet, and the impact resistance of the fiber reinforced composite is reduced. -85 degrees are preferable and 50-80 degrees are more preferable.

  In addition, the contact angle of a synthetic resin foam sheet means the contact angle (theta) value obtained with the measuring method based on the sessile drop method of JISR3257: 1999 "wetting test method of substrate glass surface". Specifically, two flat rectangular test pieces having a width of 50 mm and a length of 150 mm are cut out from the synthetic resin foam sheet and used for measurement. Measured by the droplet method using a solid-liquid interface analyzer. The dropping solution is distilled water, the amount is 1 μL, and the contact angle immediately after dropping is measured. The contact angle is calculated by the θ / 2 method. The number of tests is 10 times for each test piece, and the arithmetic average value of the measured values of all contact angles is defined as the contact angle of the synthetic resin foam sheet. Conditioning and test environment shall be temperature 20 ± 2 ° C, humidity 65 ± 5%, 16 hours or more. In addition, as a solid-liquid interface analysis apparatus, the apparatus marketed by the Kyowa Interface Science company by the brand name "DropMaster300" can be used, for example. The calculation of the contact angle can be performed using, for example, software “FAMAS” attached to a solid-liquid interface analyzer commercially available from Kyowa Interface Science Co., Ltd. under the trade name “DropMaster 300”.

If the apparent density of the synthetic resin foam sheet 1 constituting the fiber reinforced composite is too low, the cell walls of the synthetic resin foam sheet are easily broken when an impact force is applied to the fiber reinforced composite. The destruction of the cell walls easily reaches the interface between the synthetic resin foam sheet and the fiber reinforced plastic layer, and the fiber reinforced plastic layer peels off the surface of the synthetic resin foam sheet, reducing the impact resistance of the fiber reinforced composite. The synthetic resin foam sheet may be excessively deformed, and this deformation may cause cracks in the fiber reinforced plastic layer and reduce the impact resistance of the fiber reinforced composite. Of 0.1 to 1.1 g / cm ³ is preferable, and there is a concern that the impact resistance of the fiber-reinforced composite may be lowered for the same reason as described above. 9g / cm ³ is more preferable. In addition, the apparent density of a synthetic resin foam sheet says the value measured based on JISK7222.

  When the synthetic resin foam sheet constituting the fiber reinforced composite contains a crystalline synthetic resin, if the crystallinity of the synthetic resin foam sheet is too low, an impact force is applied to the fiber reinforced composite. In addition, the synthetic resin foam sheet is too soft, the synthetic resin foam sheet is excessively deformed, and this deformation may cause a crack in the fiber reinforced plastic layer, which may reduce the impact resistance of the fiber reinforced composite. 15% or more is preferable, and 20% or more is more preferable, but if it is too high, the impact absorbability of the synthetic resin foamed sheet may be reduced, and the impact resistance of the fiber-reinforced composite may be reduced. Is preferable, and 20 to 30% is more preferable.

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

  Specifically, it was preferably cut out from a synthetic resin foam sheet using a differential scanning calorimeter (trade name “DSC6220 type” manufactured by SII Nano Technology Co., Ltd.) so that there is no gap at the bottom of the aluminum measurement container. About 6 mg of a rectangular parallelepiped sample is filled, 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 synthetic 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 synthetic resin foam sheet is calculated based on the following formula.
Crystallinity of synthetic resin foam sheet (%)
= 100 × (| heat of fusion (mJ / mg) | − | heat of crystallization (mJ / mg) |) / ΔH ₀ (mJ / mg)

  Separately, four synthetic resin foam sheets are further prepared, and the crystallinity of each synthetic resin foam sheet is measured in the same manner as described above, and the arithmetic average of the respective crystallinity degrees of the five synthetic resin foam sheets. The value is defined as the crystallinity of the synthetic resin foam sheet.

  As a method for adjusting the crystallinity of the synthetic resin foam sheet, for example, as described later, a laminate obtained by laminating a fiber reinforced plastic layer forming material on the surface of the synthetic resin foam sheet is heated in its thickness direction, The crystallinity of the synthetic resin foam sheet can be adjusted by adjusting the heating temperature or the heating time during pressing. The crystallinity of the synthetic resin foam sheet can be improved by increasing the heating temperature of the laminate or increasing the heating time of the laminate.

  As described above, in the fiber-reinforced composite of the present invention, the synthetic resin foam sheet has appropriate flexibility and the number of cells by limiting the average cell diameter of the synthetic resin foam sheet to a predetermined range. Therefore, the impact force applied to the fiber reinforced composite is smoothly absorbed so that the destruction of the bubble wall due to the impact force does not reach the interface between the synthetic resin foam sheet and the fiber reinforced plastic layer, and the synthetic resin foam The sheet prevents the fiber-reinforced plastic layer from cracking due to the impact force without being excessively deformed by the impact force, and thus the fiber-reinforced composite of the present invention has excellent impact resistance. .

  Next, the manufacturing method of a synthetic resin foam sheet is demonstrated. As a method for producing a synthetic resin foam sheet, a known production method can be used. Specifically, (1) Synthetic resin is supplied to an extruder, melt-kneaded in the presence of a foaming agent such as a chemical foaming agent or a physical foaming agent, and extruded and foamed from the extruder to produce a synthetic resin foam sheet. Method (extrusion foaming method), (2) A synthetic resin and a chemical foaming agent are supplied to an extruder and melt-kneaded below the decomposition temperature of the chemical foaming agent to produce a foamable resin sheet from the extruder. Examples thereof include a method of producing a synthetic resin foam sheet by foaming a sheet.

  Examples of the chemical foaming agent include azodicarbonamide, dinitrosopentamethylenetetramine, hydrazoyl dicarbonamide, and sodium bicarbonate. 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.

  In the present invention, the average cell diameter of the synthetic resin foam sheet 1 is limited to 10 to 400 μm, but the average cell diameter of the synthetic resin foam sheet 1 is controlled, for example, by adjusting the amount of the cell core material. Can do.

  In the present invention, the tensile elongation at break of the synthetic resin foam sheet 1 can be controlled, for example, by adjusting the cell diameter of the synthetic resin foam sheet or by adjusting the cross-linking degree of the synthetic resin foam sheet. .

  In the fiber reinforced composite A of the present invention, the fiber reinforced plastic layer 2 is laminated and integrated on the surface of the synthetic resin foam sheet 1, preferably on both sides. 2 shows the fiber reinforced composite A formed by laminating and integrating the fiber reinforced plastic layers 2 and 2 on both surfaces of the synthetic resin foam sheet 1 because the fiber reinforced composite A has excellent impact resistance. However, the present invention is not limited to this, and may be determined as appropriate according to the use. Even if the fiber reinforced plastic layer 2 is laminated and integrated only on one surface of the synthetic resin foam sheet 1. Good.

  The fiber-reinforced plastic layer 2 used in the fiber-reinforced composite A of the present invention is formed by impregnating reinforcing fibers with a reinforcing synthetic resin.

  The reinforcing fibers constituting the fiber reinforced plastic layer 2 include glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, Tyranno fibers, basalt fibers, ceramic fibers, etc .; metal fibers such as stainless fibers and steel fibers Organic fibers such as aramid fiber, polyethylene fiber, polyparaphenylene benzoxador (PBO) fiber; boron fiber and the like. Reinforcing fibers may be used alone or in combination of two or more. Especially, as a reinforced fiber, carbon fiber, glass fiber, and an aramid fiber are preferable, and carbon fiber is more preferable. These reinforcing fibers have excellent mechanical strength despite being lightweight.

  The reinforcing fiber is preferably used as a reinforcing fiber substrate processed into a desired shape. Examples of the reinforcing fiber base include woven fabrics, knitted fabrics, non-woven fabrics, and face materials formed by binding (sewing) fiber bundles (strands) in which fibers are aligned in one direction. Examples of the weaving method include plain weave, twill weave and satin weave. Examples of the yarn include synthetic resin yarn such as polyamide resin yarn and polyester resin yarn, and stitch yarn such as glass fiber yarn.

  As the fiber reinforced base material, only one fiber reinforced base material may be used as a single layer, or a plurality of fiber reinforced base materials may be laminated and used as a laminate. As a laminate in which a plurality of fiber reinforced substrates are laminated, (1) a laminate in which only one kind of fiber reinforced substrate is prepared and these fiber reinforced substrates are laminated, (2) a plurality of types of fibers A laminated body in which reinforced base materials are prepared and these fiber reinforced base materials are laminated, and (3) a plurality of face materials obtained by binding (sewing) fiber bundles (strands) in which fibers are aligned in one direction with yarns. A laminate or the like prepared by stacking these face materials so that the fiber directions of the fiber bundles are different from each other and integrating the stitched face materials with a thread is used. Examples of the yarn include synthetic resin yarns such as polyamide resin yarns and polyester resin yarns, and stitch yarns such as glass fiber yarns.

  In the laminate in which the fiber reinforced base materials (1) and (2) are laminated, in the case of a laminate obtained by laminating a plurality of fabrics, the length direction of the warp (weft) constituting each fabric is It is preferable that they are arranged radially as viewed from the plane of the fabric. Specifically, as shown in FIGS. 3 and 4, when the length directions of the warps (wefts) constituting each woven 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 warp yarns (weft yarns) constituting each fabric is substantially the same in any direction without the strength of the fiber reinforced base material being biased in one direction. Since strength can be imparted, 90 ° is preferable when two woven fabrics are overlapped, and 45 ° is preferable when three or more woven fabrics are overlapped.

  In the laminate of the above (3), 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 FIG. 3 and FIG. 4, when the length direction of the fibers of the fiber bundle constituting each face material is 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 reinforced base material being biased in one direction. 90 ° is preferable when two face materials are overlapped, and 45 ° is preferable when three or more face materials are overlapped.

  The fiber reinforced plastic layer is formed by impregnating a reinforcing fiber into a reinforcing fiber. The reinforcing fibers can be bonded and integrated by the impregnated reinforcing synthetic resin. As the reinforcing synthetic resin impregnated into the reinforcing fiber, either a thermoplastic resin or a thermosetting resin may be used, but a thermosetting resin is preferably used. 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.

  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 adhesiveness with the sheet or between the fibers constituting the fiber-reinforced plastic layer forming material. 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.

  The content of reinforcing fibers in the fiber reinforced plastic layer is preferably 30 to 80% by weight, and more preferably 30 to 60% by weight. If the reinforcing fiber content is too small, the mechanical strength such as the flexural modulus of the fiber reinforced plastic layer may be lowered, and the mechanical strength such as the impact resistance of the fiber reinforced composite may not be sufficiently improved. There is. If the reinforcing fiber content is too high, the binding between the reinforcing fibers and the adhesion between the fiber reinforced plastic layer and the synthetic resin foam sheet will be insufficient, and the mechanical strength such as the bending elastic modulus of the fiber reinforced plastic layer will be insufficient. And the impact resistance of the fiber-reinforced composite may not be sufficiently improved.

  The thickness of the fiber reinforced plastic layer is preferably 0.02 to 2 mm, and more preferably 0.05 to 1 mm. The fiber reinforced plastic layer having a thickness within the above range is excellent in mechanical strength despite being lightweight.

Basis weight of the fiber-reinforced plastic layer is preferably ^{50~4000g / m 2, 100~1000g / m} 2 is more preferable. The fiber reinforced plastic layer having a basis weight within the above range is excellent in mechanical strength despite being lightweight.

  In the fiber reinforced composite of the present invention, a fiber reinforced plastic layer is laminated and integrated on the surface of a synthetic resin foam sheet excellent in shock absorption, and the fiber reinforced composite has improved mechanical strength and shock absorption. Yes. Furthermore, in the fiber reinforced composite of the present invention, since the fiber reinforced plastic layer is laminated and integrated on the surface of the synthetic resin foam sheet, the impact force applied to the fiber reinforced composite propagates to the entire fiber reinforced plastic layer. After being diffused, it is transmitted to the entire synthetic resin foam sheet. Therefore, the impact force applied to the fiber reinforced composite is efficiently absorbed by the entire synthetic resin foam sheet. Therefore, the fiber reinforced composite of the present invention has excellent impact resistance (impact absorption power). Yes. Such a fiber reinforced composite is not particularly limited, but can be suitably used as a component member of an aircraft, an automobile, a ship, a building, or the like, or a casing of an electronic device.

  Next, the manufacturing method of the fiber reinforced composite A of this invention is demonstrated. The method for producing the fiber reinforced composite A is not particularly limited. For example, a fiber reinforced plastic layer forming material including a reinforced fiber in which a reinforcing synthetic resin is impregnated on the surface (one side or both sides) of a synthetic resin foam sheet. After the laminate is manufactured, the laminate is heated, and the laminate is pressed in the thickness direction of the synthetic resin foam sheet, whereby the fiber reinforced plastic layer forming material is used as the fiber reinforced plastic layer. And a method of laminating and integrating the surfaces.

  Specifically, a fiber reinforced plastic layer forming material containing reinforcing fibers impregnated with a reinforcing synthetic resin is laminated on the surface of the above-described synthetic resin foam sheet to produce a laminate. The surface of the synthetic resin foam sheet on which the fiber reinforced plastic layer forming material is laminated may be determined according to the use of the obtained fiber reinforced composite, and is not particularly limited. Therefore, it may be at least one surface of the synthetic resin foam sheet, or may be on both surfaces. Considering the impact resistance of the obtained fiber reinforced composite, it is preferable to laminate a fiber reinforced plastic layer forming material on both surfaces of the synthetic resin foam sheet.

  In addition, about the synthetic resin used for the laminated body and the synthetic resin used for the fiber-reinforced plastic layer forming material, the synthetic resin for reinforcement, and the reinforcing fiber, the synthetic resin foamed sheet and the fiber-reinforced plastic layer in the fiber-reinforced composite described above Since these are the same as the synthetic resin, the reinforcing synthetic resin and the reinforcing fiber used in the above, detailed description thereof will be omitted.

  The method of impregnating the reinforcing synthetic resin in the reinforcing fiber is not particularly limited. For example, (1) a method of immersing the reinforcing fiber in the reinforcing synthetic resin and impregnating the reinforcing synthetic resin in the reinforcing fiber, (2) A method in which a reinforcing synthetic resin is applied to the reinforcing fiber and the reinforcing fiber is impregnated with the reinforcing synthetic resin, and (3) a sheet containing the reinforcing synthetic resin is laminated on the reinforcing fiber substrate and then heated. Examples thereof include a method in which the reinforcing synthetic resin contained in the sheet is impregnated into the reinforcing fiber constituting the reinforcing fiber substrate by pressurization. In the methods (1) and (2), the reinforcing fiber is used as the reinforcing fiber base, and the reinforcing fiber base is immersed in the reinforcing synthetic resin or the reinforcing synthetic resin is applied to the reinforcing fiber base. By doing so, the reinforcing fiber constituting the reinforcing fiber base can be impregnated with the reinforcing synthetic resin.

  A commercially available reinforcing fiber plastic layer forming material including a reinforcing fiber substrate or a reinforcing fiber substrate impregnated with a reinforcing synthetic resin can be used. The reinforcing fiber substrate is commercially available from Mitsubishi Rayon under the trade name “Pyrofil”, for example. Further, a fiber reinforced plastic layer forming material including a reinforced fiber base material impregnated with a thermosetting resin is commercially available from Mitsubishi Rayon Co., Ltd. under the trade name “Pyrofil Prepreg”. A fiber reinforced plastic layer forming material including a reinforced fiber base material impregnated with a thermoplastic resin is commercially available from Nagase Chemtech under the trade name “NNGF60-03s”.

  The laminate is pressed in the thickness direction while heating the laminate produced as described above in a general-purpose manner such as an infrared heater. The fiber reinforced plastic layer forming material and the synthetic resin foam sheet are heated by heating the laminate. By heating the laminate, the reinforcing synthetic resin contained in the fiber reinforced plastic layer forming material is softened to have fluidity, and if necessary, the fiber reinforced plastic layer forming material and the synthetic resin foam sheet are desired. Mold into shape. When the reinforcing synthetic resin includes a thermosetting resin, the thermosetting resin is softened to be in 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.

  If the heating temperature of the laminate is too low, the softening of the reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material is insufficient, and the fiber reinforced plastic layer formed from the fiber reinforced plastic layer forming material is The synthetic resin foam sheet may not be able to be laminated and integrated with sufficient strength. If it is too high, the bubbles in the synthetic resin foam sheet are destroyed by heat, and the resulting fiber-reinforced composite is lightweight and absorbs shock. (The glass transition temperature of the synthetic resin for reinforcement −60 ° C.) to (the glass transition temperature of the synthetic resin for reinforcement + 80 ° C.) is preferable, and the glass transition temperature of the synthetic resin for reinforcement −50 ° C. ) To (glass transition temperature of the reinforcing synthetic resin + 70 ° C.) is more preferable. In the present invention, the heating temperature of the laminate B refers to the surface temperature of the fiber reinforced plastic layer forming material of the laminate B. 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, it is necessary to adjust the heating temperature of the laminate so that all thermosetting resins are in a fluid state without curing. There is.

  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.

  When the reinforcing synthetic resin contained in the fiber reinforced plastic layer forming material contains a thermosetting resin, the fiber is reinforced by binding and fixing the reinforcing fibers together by curing the thermosetting resin. This fiber reinforced plastic layer is laminated and integrated on the surface of the foamed molded body with a cured thermosetting resin contained in the fiber reinforced plastic layer to obtain a fiber reinforced composite.

  The heating temperature for curing the uncured thermosetting resin contained in the fiber reinforced plastic layer forming material of the laminate may be the same as or changed from the heating temperature of the laminate during pressing. Although it is good, in order to accelerate | stimulate hardening of a thermosetting resin, it is preferable to raise the heating temperature of a laminated body.

  If the heating temperature for curing the uncured thermosetting resin contained in the fiber reinforced plastic layer forming material of the laminate is too low, curing of the thermosetting resin becomes insufficient and the resulting fiber The mechanical strength of the reinforced composite may be reduced, and if it is too high, the bubbles of the synthetic resin foam sheet may be destroyed by heat, and the lightweight and impact resistance of the resulting fiber reinforced composite may be reduced. Therefore, (Glass transition temperature of thermosetting resin−50 ° C.) to (Glass transition temperature of thermosetting resin + 50 ° C.) is preferable, (Glass transition temperature of thermosetting resin−40 ° C.) to (Thermosetting resin) Glass transition 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 highest glass transition temperature.

  In addition, when the reinforcing synthetic resin contained in the fiber reinforced plastic layer forming material contains a thermoplastic resin, the above-described curing step is not required unlike the case where it contains a thermosetting resin, and the fiber reinforced plastic layer. The forming material is cooled and laminated and integrated as a fiber reinforced plastic layer on the surface of the synthetic resin foam sheet to obtain a fiber reinforced composite. Also in this case, the fiber reinforced plastic layer is laminated and integrated on the surface of the foam molded article by the action of the thermoplastic resin of the fiber reinforced plastic layer.

  When a plurality of fiber reinforced plastic layer forming materials are laminated on the surface of the foamed molded product, the fiber reinforced plastic layer forming materials are reinforced by heating and pressing the above laminated product. The fiber reinforced plastic layer is formed by laminating and integrating with a reinforcing synthetic resin contained in the plastic layer forming material.

  The above-described heating and pressing step of the laminate may be performed under atmospheric pressure or may be performed under reduced pressure. When the heating and pressing process of the laminate is performed under reduced pressure, excess reinforcing synthetic resin in the fiber reinforced plastic layer forming material can be sucked and removed, and in the fiber reinforced plastic layer forming material or fiber reinforced. The air existing between the plastic layer forming material and the synthetic resin foam sheet or between the fiber reinforced plastic layer forming materials can be sucked and removed, and the reinforcing fiber of the resulting fiber reinforced plastic layer is synthesized for reinforcement. The resin can be more firmly bound and fixed and integrated, and the fiber-reinforced plastic layer and the synthetic resin foam sheet can be integrated more firmly.

  If the degree of crystallinity of the synthetic resin foam sheet before the fiber reinforced plastic layer is laminated and integrated is too high, the fluidity of the thermoplastic polyester resin constituting the synthetic resin foam sheet is lowered, and the synthetic resin foam sheet The heat-fusability between the fiber reinforced plastic layer and the fiber reinforced plastic layer is reduced, the integration of the synthetic resin foam sheet and the fiber reinforced plastic layer is insufficient, and the impact resistance of the resulting fiber reinforced composite may be reduced. Therefore, it is preferably 14% or less, and more preferably 10% or less. The method for measuring the crystallinity of the synthetic resin foam sheet before the fiber reinforced plastic layer is laminated and integrated is the same as the method described above, and the description thereof is omitted.

  When heating a laminate obtained by laminating a fiber reinforced plastic layer forming material containing reinforcing fibers impregnated with a reinforcing synthetic resin on the surface of the synthetic resin foam sheet, the synthetic resin foam sheet and the fiber reinforced plastic layer are heated. Simultaneously with the integration, by increasing the crystallinity of the synthetic resin foam sheet, the heat resistance of the synthetic resin foam sheet can be improved, and by improving the crystallinity of the synthetic resin foam sheet, The tensile strength at break of the synthetic resin foam sheet can be increased to improve the impact resistance of the fiber reinforced composite.

If the apparent density of the obtained fiber-reinforced composite is too low, the impact resistance of the fiber-reinforced composite may be reduced, and if it is too high, the lightness of the fiber-reinforced composite may be impaired. 0.3-1.5 g / cm < ³ > is preferable and 0.5-1.3 g / cm < ³ > is more preferable. In addition, the apparent density of a fiber reinforced composite means the value measured based on JISK7222.

  Next, an example of a procedure for heating and pressing the above-described laminated body under reduced pressure will be described. As shown in FIG. 5, a laminate B is formed by laminating a fiber reinforced plastic layer forming material 21 on the surface of the synthetic resin foam sheet 1. In FIG. 5, fiber reinforced plastic layer forming materials 21 and 21 are laminated on both surfaces of the synthetic resin foam sheet 1 to form a laminate B.

  Further, as shown in FIG. 5, after the pressing plate 6b is placed on the fiber reinforced plastic layer forming material 21 of the laminate B, the breather cloth 4 is stacked on the pressing plate 6b via the release film 3. The release film 3 is configured to be easily peelable from the fiber reinforced plastic layer forming material 21. The release film 3 is composed of a synthetic resin film. Examples of such a synthetic resin include fluorine resins such as tetrafluoroethylene-ethylene copolymer (tetrafluoroethylene-ethylene copolymer). Can be mentioned.

  The breather cloth 4 is used for absorbing excess reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material 21 and is not deformed or altered when the laminate B is heated or pressurized. Often, non-woven fabrics are mentioned. Examples of the non-woven fabric include non-woven fabric made of amide resin fibers such as nylon fibers, polyester resin fibers, and the like, and glass cloth.

  Next, the laminated body B is placed on the pressing plate 6 a, the bagging film 5 is put on the laminated body B, and the laminated body B is sealed with the bagging film 5. The bagging film 5 is a film for sealing the laminate B and evacuating the entire laminate B. Examples of the synthetic resin constituting the bagging film 5 include amide resins such as nylon. A sealing material 7 is interposed between the entire circumference of the outer peripheral edge of the bagging film 5 and the pressing plate 6a to ensure airtightness.

  Thereafter, the space 8 sealed with the bagging film 5 is evacuated to depressurize the space 8. Next, the laminated body B in the space portion 8 is heated after the pressure reduction in the space portion 8 sealed with the bagging film 5 or simultaneously with the start of the pressure reduction, so that the reinforcing synthetic resin in the fiber reinforced plastic layer forming material 21 is heated. Soften. After the reinforcing synthetic resin is softened, the laminate B is pressed in the laminating direction of the fiber reinforced plastic layer forming material 21 with respect to the laminate B by the pressure plates 6a and 6b and the heating is continued. During the heating and pressurization of the laminate B, the reduced pressure state in the space 8 is maintained.

  By pressurizing the laminate B, air in the fiber reinforced plastic layer forming material can be more surely removed, and voids can be prevented from being generated in the fiber reinforced plastic layer, and adhesion between fibers can be prevented. In addition, the fiber reinforced plastic layer forming material is deformed along the surface of the foam, and the fiber reinforced plastic layer forming material is pressed against the surface of the foam to cause the fiber reinforced plastic layer forming material to It can be laminated in a state of being in close contact with the surface. Furthermore, in the state where the fiber reinforced plastic layer forming material is laminated so as to be in close contact with the surface of the foam, the air existing at the interface between the fiber reinforced plastic layer forming material and the surface of the foam is substantially complete. The fiber-reinforced plastic layer forming material is in a state of being in good contact with the surface of the synthetic resin foam sheet.

  In addition, by pressing the laminate B, the reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material is blended with the entire reinforcing fiber so that the reinforcing fibers are made of the minimum amount of reinforcing synthetic resin. It can be surely bound. In this way, reinforcing fibers can be bound together with the minimum amount of reinforcing synthetic resin, so there is no extra reinforcing synthetic resin between the reinforcing fibers, and the reinforcing fibers are highly oriented. The mechanical strength of the fiber reinforced plastic layer can be improved, and the appearance of the fiber reinforced plastic layer can be improved.

  Further, when a plurality of fiber reinforced plastic layer forming materials are stacked, the fiber reinforced plastic layer forming materials stacked on each other by pressing can be firmly integrated, and the resulting fiber reinforced composite Is excellent in mechanical strength.

  On the other hand, when the laminate B is pressurized, excess reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material may be raised on the surface of the fiber reinforced plastic layer forming material. The excess reinforcing synthetic resin is absorbed by the breather cloth 4, and the surface of the fiber reinforced plastic layer of the resulting fiber reinforced composite has no extra reinforcing synthetic resin and has an excellent appearance. .

  In the state where the laminate is pressurized as described above, heating of the laminate is continued, and this heating increases the crystallinity of the synthetic resin foam sheet of the laminate, and in the fiber reinforced plastic layer forming material. When the reinforcing synthetic resin contained includes a thermosetting resin, the thermosetting resin is cured.

  The reinforcing fibers in the fiber reinforced plastic layer forming material are bound and fixed by the curing of the thermosetting resin, and the fiber reinforced plastic layer forming material is deformed along the surface of the foam. The fiber reinforced composite A can be obtained by being laminated and integrated with a thermosetting resin cured on the surface of the synthetic resin foam sheet.

  Further, when the reinforcing synthetic resin contained in the fiber reinforced plastic layer forming material contains a thermoplastic resin, the reinforcing fibers in the fiber reinforced plastic layer forming material are bound and fixed by cooling described later. In addition, the fiber reinforced plastic layer forming material may be laminated and integrated with a thermoplastic resin on the surface of the synthetic resin foam sheet as a fiber reinforced plastic layer in a state of being deformed along the surface of the foam to obtain a fiber reinforced composite A. it can.

  Next, after cooling the fiber reinforced composite and releasing the pressure applied to the fiber reinforced composite, the decompression in the space 8 is released, and then the space 8 is opened to release the fiber reinforced composite A. Just take it out.

  In the above description, the case where the laminate B is covered with the bagging film 5 and the laminate B is sealed with the bagging film 5 and the pressurization of the laminate B is performed under reduced pressure is described. You may carry out under a normal pressure. Specifically, in FIG. 5, the laminate B is sandwiched between the pressing plates 6 a and 6 b without laminating or covering the release film 3, the breather cloth 4 and the bagging film 5 on the laminate B and the laminate B is The fiber reinforced composite A may be manufactured by heating and pressing the laminate B under normal pressure by the pressing plates 6a and 6b.

  In the manufacturing method of the fiber reinforced composite A described above, the pressing plates 6a and 6b do not have to be flat, and may have a molding surface having a desired shape. The molded resin foam sheet and the fiber reinforced plastic layer forming material of the laminate B are formed into a desired shape by the molding surfaces of the pressing plates 6a and 6b, and the fiber reinforced plastic layer forming material is formed on the surface of the synthetic resin foam sheet. The fiber reinforced composite A having a desired shape can be obtained by laminating and integrating the fiber reinforced plastic layers.

  Moreover, as a manufacturing method of a fiber reinforced composite, a well-known thermoforming method can be used, for example, a vacuum forming method, a pressure forming method, etc. are mentioned. Examples of thermoforming methods that apply vacuum forming method and pressure forming method include straight forming method, drape forming method, plug assist forming method, plug assist reverse draw forming method, air slip forming method, snapback forming method, reverse draw method. Examples include molding methods, plug assist / air slip molding methods, match molding methods, and thermoforming methods that combine these molding methods. Good appearance even when fiber reinforced plastic layer forming materials with poor moldability are used. Since a simple fiber reinforced composite can be obtained, the match molding method is preferable.

  An example of the point which manufactures a fiber reinforced composite using a thermoforming method is demonstrated concretely. First, the above-mentioned fiber reinforced plastic layer forming material 21 is laminated on at least one surface of the synthetic resin foam sheet 1 to produce a laminate M (lamination step). 6 shows the case where the fiber reinforced plastic layer forming materials 21 and 21 are laminated on both surfaces of the synthetic resin foam sheet 1, the fiber reinforced plastic layer forming material 21 is laminated only on one surface of the synthetic resin foam sheet 1. May be.

  Further, the release film 3 may be laminated on the fiber reinforced plastic layer forming material 21 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 reinforced plastic layer forming material 2 and the male and female molds. For example, tetrafluoroethylene-ethylene copolymer Fluorine resins such as coalescence (tetrafluoroethylene-ethylene copolymer), polystyrene resins, polyester resins and the like can be mentioned.

  Next, a molding process is performed following the above-described lamination process. First, as shown in FIG. 6, in the molding process, the synthetic resin foam sheet 1 of the laminate M is gripped, while the fiber reinforced plastic layer forming material 21 is not gripped at all.

  Thus, by not grasping the fiber reinforced plastic layer forming material 21, when the laminate M is press-molded, it can be freely moved on the synthetic resin foam sheet 1, and accompanying the press molding of the synthetic resin foam sheet 1. It is no longer necessary for the fiber reinforced plastic layer forming material 21 to follow the elongation, and the fiber reinforced plastic layer forming material 21 can be smoothly press-molded independently by the male and female dies 41, 42, making press molding difficult. The fiber-reinforced plastic layer forming material 2 can be easily and accurately press-molded on the synthetic resin foam sheet 1.

  In addition, the synthetic resin foam sheet 1 can be held stably by holding the synthetic resin foam sheet 1 in an accurate position with respect to the male and female molds 41 and 42 when the laminate M is press-molded. The synthetic resin foam sheet 1 can be accurately press-molded, and the fiber-reinforced plastic layer forming material 21 is stably press-molded on the stably supported synthetic resin foam sheet 1 to obtain a desired shape. The synthetic resin foam sheet 1 and the fiber reinforced plastic layer forming material 21 of the laminate M can be accurately press-formed into a desired shape.

  The synthetic resin foam sheet 1 may be held using a known clamp 5. Further, the position where the synthetic resin foam sheet 1 is gripped is not particularly limited as long as the above object is achieved. For example, the opposing outer peripheral edge of the synthetic resin foam sheet 1 or the four-side outer peripheral edge of the foam sheet. Etc.

  As described above, the laminate M is heated after holding the synthetic resin foam sheet 1. By heating the laminate M, the reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material 21 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.

  By heating the laminated body M, the fiber reinforced plastic layer forming material 21 is in a state in which the reinforcing synthetic resin impregnated therein can be pressed into a fluid state, and the synthetic resin foamed sheet 1 Also, it is softened by heating and can be easily molded by press molding.

  In this state, as shown in FIGS. 6 and 7, the laminate M is disposed between the male and female dies 41 and 42, and the male and female dies 41 and 42 are clamped to form a laminate by press molding. The synthetic resin foam sheet 1 of the body M is formed into a desired shape, and the fiber reinforced plastic layer forming material 21 is formed into a desired shape while sliding on the synthetic resin 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 reinforced plastic layer forming material 21 maintains fluidity. Since the laminate M is pressed by the male and female dies 41 and 42 during press molding, the reinforcing synthetic resin contained in the fiber reinforced plastic layer forming material 21 oozes out on the surface of the fiber reinforced plastic layer forming material 21. Thus, a skin layer is formed on the surface of the fiber reinforced plastic layer forming material 21, and thus the surface of the obtained fiber reinforced composite A is formed as a smooth surface where the fibers of the fiber reinforced plastic layer are not exposed.

  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.

  Next, after the laminated body M is press-molded by male and female dies 41 and 42 into a desired shape, the fiber reinforced plastic layer forming material 21 is impregnated with an uncured thermosetting resin. The uncured thermosetting resin contained in the fiber reinforced plastic layer forming material 21 of the body M is cured, and the reinforced fibers of the fiber reinforced plastic layer forming material are bonded and fixed with a cured thermosetting resin. The fiber reinforced plastic layer forming material 21 is used as the fiber reinforced plastic layer 2, and the fiber reinforced plastic layer 2 is laminated and integrated on at least one surface of the synthetic resin foam sheet 1 with a cured thermosetting resin. Manufacture (curing process).

  The heating temperature for curing the uncured thermosetting resin contained in the fiber reinforced plastic layer forming material 21 of the laminate M may be the same as the heating temperature of the laminate M during press molding. Although it may be changed, it is preferable to raise the heating temperature of the laminate M in order to promote the curing of the thermosetting resin.

  Also, when the reinforcing synthetic resin impregnated in the fiber reinforced plastic layer forming material 21 is a thermoplastic resin, unlike the case of the thermosetting resin, the above-described curing process is not necessary and cooling is performed as described later. The fiber-reinforced plastic layer 21 is made into the fiber-reinforced plastic layer 2 by solidifying the thermoplastic resin by bonding, and binding and fixing the fiber-reinforced plastic layer-forming material with the solidified thermoplastic resin. The fiber reinforced composite A is manufactured by laminating and integrating at least one surface of the synthetic resin foamed sheet 1 with the solidified thermoplastic resin of the plastic layer 2.

  Next, after the fiber reinforced composite A is cooled as necessary, the male and female molds 41 and 42 can be opened to obtain the fiber reinforced composite A (see FIG. 8). In the obtained fiber reinforced composite A, the fiber reinforced plastic layer 2 in which the reinforcing fibers are bound to each other by the reinforcing synthetic resin and formed into a desired shape along the male and female molds 41 and 42 is formed of the synthetic resin foam sheet 1. It is laminated and integrated so as to be in close contact with the entire surface. In addition, in FIG. 8, although the release film 3 was shown in the state laminated | stacked on the fiber reinforced plastic layer 2, the release film 3 peels easily from the fiber reinforced plastic layer 2 of the fiber reinforced composite A, Can be removed. Moreover, in FIG. 8, the synthetic resin foam sheet 1 showed the state which cut off the both ends.

  Since the fiber-reinforced composite of the present invention has the above-described configuration, excellent impact resistance is obtained by a combination of a synthetic resin foam sheet having a predetermined average cell diameter and contact angle and a fiber-reinforced plastic layer. And has heat resistance.

It is the schematic diagram which showed the point which measures the average bubble diameter of a foam sheet. It is sectional drawing which showed the fiber reinforced composite_body | complex. It is the figure which showed the orientation of the reinforced fiber which comprises the fiber reinforced plastic layer. It is the figure which showed the orientation of the reinforced fiber which comprises the fiber reinforced plastic layer. It is the schematic cross section which showed an example of the manufacturing point of a fiber reinforced composite. 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 synthetic resin foam sheet.

  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
An aluminum plate is prepared as the pressing plate 6a, and a release agent (trade name “Chem Lease 2166” manufactured by Chem Lease Japan Co., Ltd.) is applied to the upper surface of the aluminum plate and left for a day. gave.

Fiber reinforced substrate with a thickness of 0.23 mm containing 40% by weight of an uncured epoxy resin (glass transition temperature: 126 ° C.) as a thermosetting resin in a fiber reinforced base material formed from a twill weave made of carbon fiber Two plastic layer forming materials (CFRP, trade name “Pyrofil Prepreg TR3523 381GMP” manufactured by Mitsubishi Rayon Co., Ltd., basis weight: 200 g / m ² ) were prepared. The fiber reinforced plastic layer forming material was cut so as to be a planar square shape with a side of 16 cm. Two fiber reinforced plastic layer forming materials were superposed so that the angle formed by the length direction of their warps was 90 °.

  As the synthetic resin foam sheet, a polyethylene terephthalate foam sheet having a planar square shape with a side of 16 cm and a thickness of 0.4 mm was used. The average cell diameter, contact angle, tensile elongation at break and apparent density of the polyethylene terephthalate foamed sheet were as shown in Table 1. The polyethylene terephthalate foam sheet contained polyethylene terephthalate (trade name “SA-135”, melting point: 247.1 ° C., manufactured by Mitsui Chemicals, Inc.) as a resin component.

  Next, two superposed fiber reinforced plastic layer forming materials 21 are placed on the release treatment surface of the aluminum plate 6a, and the polyethylene terephthalate foam sheet 1 is placed on these fiber reinforced plastic layer forming materials 21. I put it.

  Separately from the above, two fiber reinforced plastic layer forming materials 21 identical to those described above were prepared, and the two fiber reinforced plastic layer forming materials were superposed in the same manner as described above. The two laminated fiber reinforced plastic layer forming materials 21 were placed on the polyethylene terephthalate foamed sheet 1 to produce a laminate B.

  Thereafter, after the pressing plate 6b is placed on the fiber reinforced plastic layer forming material 21 on the upper side of the laminate B, the release film 3 having a through hole (manufactured by AIRTECH) is provided so as to cover the entire pressing plate 6b. Product name “WL5200B-P”) and breather cloth 4 (product name “AIRWEAVE N4” manufactured by AIRTECH) were sequentially laminated. The breather cloth 4 also covered both side surfaces (left and right side surfaces in FIG. 5) of the laminate B. The release film 3 is formed of a tetrafluoroethylene-ethylene copolymer film, and has a large number of through-holes that penetrate between both surfaces and allow the thermosetting resin in the fiber reinforced plastic layer forming material 21 to pass therethrough. It was. The breather cloth 4 is formed of a nonwoven fabric composed of polyester resin fibers, and is configured to be impregnated with a thermosetting resin.

  The laminate B is covered with a bagging film 5 (trade name “WL7400” manufactured by AIRTECH), and a sealant tape (manufactured by AIRTECH) with the sealing material 7 between the outer peripheral edge of the bagging film 5 and the aluminum plate facing the bagging film 5. The laminate B was sealed with the bagging film 5 in an airtight manner using a trade name “GS43MR”). The bagging film 5 was made of a nylon film. A back valve 11 (trade name “VAC VALVE 402A” manufactured by AIRTECH) was disposed on a part of the bagging film 5 to produce a laminated structure.

  Next, the laminated structure is supplied into an autoclave for heat curing test (trade name “DL-2010” manufactured by Hanyuda Iron Works Co., Ltd.), and the back valve 11 of the laminated structure is connected to a vacuum line. The sealed space 8 was evacuated from the laminate B in the direction of the breather cloth 4 covering the side surfaces of the laminate B, and the pressure was reduced to 0.10 MPa. Note that the decompression of the space 8 was continued after that.

  Thereafter, the temperature inside the autoclave is raised to 90 ° C. at a rate of temperature rise of 4 ° C./minute to heat the laminate B, and the inside of the autoclave is heated to 90 ° C. for 90 minutes to form a fiber reinforced plastic layer. The fiber reinforced plastic layer forming material is deformed along the surface of the polyethylene terephthalate foamed sheet by softening the thermosetting resin in the material to have fluidity, and the air present in the fiber reinforced plastic layer forming material Was aspirated and removed.

  Next, the inside of the autoclave is pressurized to 0.3 MPa gauge pressure to apply a pressing force to the laminate B, and the inside of the autoclave is heated to 130 ° C. at a rate of temperature rise of 4 ° C./min. The inside of the autoclave is heated at 130 ° C. for 60 minutes to cure the thermosetting resin in the fiber reinforced plastic layer forming material and the heat of curing the fiber reinforced plastic layer forming materials 21, 21. A fiber reinforced composite A was obtained by laminating and integrating both surfaces of the polyethylene terephthalate foam sheet 1 with a curable resin. The fiber reinforced plastic layer forming materials 21 and 21 are integrated by curing the thermosetting resin contained therein to form a fiber reinforced plastic layer. The excess thermosetting resin in the fiber reinforced plastic layer forming materials 21 and 21 was absorbed by the breather cloth 4 through the through-holes and the outside of the release film 3 due to the pressurization to the laminate B.

  When the inside of the autoclave was cooled and the inside of the autoclave reached 60 ° C., the pressure inside the autoclave was released and the pressure was returned to atmospheric pressure, and the fiber reinforced composite A was taken out. In the fiber reinforced composite A, the fiber reinforced plastic layers 2 and 2 were laminated and integrated on both surfaces of the polyethylene terephthalate foam sheet.

(Example 2)
Eight pieces of fiber reinforced plastic layer forming materials used in Example 1 were prepared. Four fiber reinforced plastic layer forming materials were sequentially overlapped so that their warp length directions were 0 °, 90 °, 45 °, and −45 °. A portion where all the four fiber reinforced plastic layer forming materials overlap each other was cut so as to form a planar square shape with a side of 16 cm. The length direction of the warp is taken as a reference (0 °) with respect to the length direction of the warp of an arbitrary fiber reinforced plastic layer forming material, and the clockwise angle is + (plus) with respect to the reference direction. The counterclockwise direction was expressed as-(minus).

  Except that four fiber reinforced plastic layer forming materials are used as the fiber reinforced plastic layer forming material, and four fiber reinforced plastic layer forming materials 21 are laminated on both sides of the polyethylene terephthalate foam sheet. A fiber reinforced composite A was obtained in the same manner as in Example 1.

(Example 3)
Twelve fiber-reinforced plastic layer forming materials used in Example 1 were prepared. Six fiber reinforced plastic layer forming materials were sequentially stacked such that their warp length directions were 0 °, 45 °, 90 °, 90 °, −45 °, 0 °. A portion where all of the six fiber reinforced plastic layer forming materials overlap was cut into a planar square shape with a side of 16 cm. The length direction of the warp is taken as a reference (0 °) with respect to the length direction of the warp of an arbitrary fiber reinforced plastic layer forming material, and the clockwise angle is + (plus) with respect to the reference direction. The counterclockwise direction was expressed as-(minus).

  The fiber reinforced plastic layer forming material is a laminate of 6 fiber reinforced plastic layer forming materials, and 6 fiber reinforced plastic layer forming materials 21 are laminated on both sides of the polyethylene terephthalate foam sheet. A fiber reinforced composite A was obtained in the same manner as in Example 1.

Example 4
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 1.2 mm was used. Except for this, a fiber-reinforced composite A was obtained in the same manner as in Example 1.

(Example 5)
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 1.9 mm was used. Except for this, a fiber-reinforced composite A was obtained in the same manner as in Example 1.

(Example 6)
As a synthetic resin foamed sheet, a thermoplastic polyester resin foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a flat square shape with a side of 16 cm and a thickness of 1.2 mm is used. A fiber-reinforced composite A was obtained in the same manner as in Example 1 except that it was used. The thermoplastic polyester resin foamed sheet comprises, as resin components, 70% by weight of polyethylene terephthalate (trade name “SA-135”, melting point: 247.1 ° C., manufactured by Mitsui Chemicals) and PCT resin (polycyclohexylenedimethylene terephthalate) (yeast Product name “Tritan FX-100” manufactured by Man Chemical Company Ltd., aromatic dicarboxylic acid component: terephthalic acid, diol component: 79 mol% of 1,4-cyclohexanedimethanol and 2,2,4,4-tetramethyl- 1,3-cyclobutanediol 21 mol%, glass transition temperature: 108 ° C., intrinsic viscosity: 0.72) 30 wt%.

(Example 8)
As a synthetic resin foam sheet, a modified polyphenylene ether resin foam sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 0.4 mm A fiber reinforced composite A was obtained in the same manner as in Example 1 except that was used. The modified polyphenylene ether resin foam sheet is a mixture of polyphenylene ether and polystyrene resin (trade name “NORYL NLV025-111” manufactured by GE Plastics, polyphenylene ether amount: 70 wt%, polystyrene resin amount: 30 wt%) Modified polyphenylene ether resin (modified PPE, phenylene ether (PPE) component: 40% by weight) obtained by mixing 57.1% by weight and 42.9% by weight of polystyrene (trade name “HRM-26” manufactured by Toyo Styrene Co., Ltd.) It contained 0.55 parts by weight of powder talc with respect to 100 parts by weight of styrene (PS component: 60% by weight).

Example 9
As the synthetic resin foamed sheet, a polyamide resin foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 0.8 mm was used. Except for this, a fiber-reinforced composite A was obtained in the same manner as in Example 1. The polyamide resin foam sheet is made of a styrene / maleic anhydride copolymer (manufactured by Arco Chemical Co., Ltd.) as a modifier with respect to 100 parts by weight of a polyamide resin (trade name “A1025” manufactured by Unitika Ltd., melting point 220 ° C.) as a resin component. 232 ") and 2 parts by weight, and 1 part by weight of talc fine powder as an inorganic component.

(Example 10)
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a side square shape of 350 mm and a thickness of 0.4 mm was prepared. .

Next, a thickness of 0.23 mm in which 40% by weight of an uncured epoxy resin (glass transition temperature: 121 ° C.) is contained as a thermosetting resin in a reinforcing fiber base formed from a twill fabric made of carbon fibers. ^Two fiber reinforced plastic layer forming materials (trade name “Pyrofil Prepreg TR3523-395GMP” manufactured by Mitsubishi Rayon Co., Ltd., basis weight: 200 g / m ² ) were prepared. The fiber reinforced plastic layer forming material had a planar square shape with a side of 250 mm.

  Two fiber-reinforced plastic layer forming materials were superposed so that their warp length directions were at an angle of 90 ° to each other. Two fiber reinforced plastic layer forming materials were integrated with an epoxy resin contained therein to form one fiber reinforced plastic layer forming material. One more fiber-reinforced plastic layer forming material was produced in the same manner.

A fiber reinforced plastic layer forming material 21 is laminated on both surfaces of the polyethylene terephthalate foamed sheet 1, and crimping is performed using a crimping instrument (trade name “Share Shot Iron SI-39S” manufactured by Ishizaki Electric Manufacturing Co., Ltd., instrument weight 860 g). The epoxy resin contained in the fiber reinforced plastic layer forming material 21 with a crimping surface temperature of 18 ± 3 ° C. and crimping with the weight of the crimping tool alone (559 ± 196 Pa (5.7 ± ² gf / cm ² )). Then, the fiber reinforced plastic layer forming material 21 is temporarily bonded to both surfaces of the polyethylene terephthalate foam sheet 1, and then the release film 3 (trade name “Oydis” manufactured by Kurabo Industries, special polystyrene resin film, thickness 50 μm) is attached. A laminate M was manufactured by laminating on the fiber reinforced plastic layer forming material 21 (lamination step).

  Next, the polyethylene terephthalate foamed sheet 1 of the laminate M was gripped using clamps at the edges of the two opposite sides, while the fiber reinforced plastic layer forming material 21 was not gripped at all. Thereafter, the uncured epoxy resin impregnated in the fiber reinforced plastic layer forming material 21 by heating the laminate M for 5 seconds so that the surface temperature of the fiber reinforced plastic layer forming material 21 becomes 150 ° C. It was made into the state which has fluidity | liquidity, without softening and hardening. In this state, the temporary adhesion between the polyethylene terephthalate foam sheet 1 and the fiber reinforced plastic layer forming material 21 is completely released, and the fiber reinforced plastic layer forming material 21 is freely movable on the polyethylene terephthalate foam sheet 1. It was.

  Subsequently, as shown in FIGS. 6 and 7, 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 for 1 minute, thereby pressing. The foamed sheet 1 of the laminate M was formed into a desired shape by molding, and the fiber-reinforced plastic layer forming material 21 was formed into a desired shape while sliding on the polyethylene terephthalate foamed sheet 1. At the time of press molding, the surface temperature of the fiber reinforced plastic layer forming material 21 of the laminate M is maintained at 140 ° C., and the epoxy resin contained in the fiber reinforced plastic layer forming material 21 maintains fluidity. Controlled.

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

  Next, the laminate M is heated for 5 minutes so that the surface temperature of the fiber reinforced plastic layer forming material 21 becomes 140 ° C., and the uncured epoxy contained in the fiber reinforced plastic layer forming material 21 The resin is cured, and the reinforced fibers of the fiber reinforced plastic layer forming material are bonded and fixed with a cured epoxy resin to fix the fiber reinforced plastic layer forming material 21 to the fiber reinforced plastic layer H1, and this fiber reinforced plastic layer H1 is The fiber-reinforced composite A was manufactured by laminating and integrating both sides of the thermoplastic polyester resin extruded foam sheet 1 with the cured epoxy resin (curing step).

  Thereafter, the fiber reinforced composite A was cooled until the surface temperature of the fiber reinforced plastic layer 2 became 30 ° C. or lower, and then the male and female molds 41 and 42 were opened to obtain the fiber reinforced composite A. In the obtained fiber reinforced composite A, the fiber reinforced plastic layer 2 in which the reinforced fibers are bound to each other by the cured epoxy resin and formed into a desired shape along the male and female molds 41 and 42 is formed of the polyethylene terephthalate foam sheet 1. It was laminated and integrated so as to be in close contact with the entire surface.

(Example 11)
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a flat square shape with a side of 350 mm and a thickness of 1.2 mm was used. Except for this, a fiber-reinforced composite A was obtained in the same manner as in Example 10.

  The obtained fiber reinforced composite A is an epoxy in which a fiber reinforced plastic layer 2 in which reinforced fibers are bound and fixed by a cured epoxy resin and formed into a desired shape along male and female molds 41 and 42 is cured. The resin was laminated and integrated with both sides of the thermoplastic polyester resin extruded foam sheet 1 so as to be in close contact with each other along their surfaces.

(Example 12)
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a side square shape of 350 mm and a thickness of 0.4 mm was prepared. .

  Next, as a fiber reinforced plastic layer forming material before lamination and integration, terephthalic acid and adipine are applied to a reinforcing fiber base material formed from a satin weaving fabric made of glass fiber (trade name “WE181D” manufactured by Nitto Boseki Co., Ltd.). Crystalline thermoplastic polyester-based resin (trade name “G-125”, manufactured by Tokyo Ink Co., Ltd., melting point: 100.6 ° C., glass transition temperature: 8.3) having acid as the main dicarboxylic acid component and ethylene glycol as the main glycol component Two fiber reinforced plastic layer forming materials were prepared by impregnating 40 parts by weight of 60 ° C.) with a reinforcing fiber base material. The fiber reinforced plastic layer forming material had a planar square shape with a side of 250 mm.

  Two fiber-reinforced plastic layer forming materials were superposed so that their warp length directions were at an angle of 90 ° to each other. Two fiber reinforced plastic layer forming materials were integrated with each other by a thermoplastic epoxy resin contained therein to form one fiber reinforced plastic layer forming material. One more fiber-reinforced plastic layer forming material was produced in the same manner.

A fiber reinforced plastic layer forming material 21 is laminated on both surfaces of the polyethylene terephthalate foamed sheet 1, and crimping is performed using a crimping instrument (trade name “Share Shot Iron SI-39S” manufactured by Ishizaki Electric Manufacturing Co., Ltd., instrument weight 860 g). Crystalline thermoplasticity contained in the fiber reinforced plastic layer forming material 21 by pressure bonding with the weight of only the pressure bonding device [559 ± 196 Pa (5.7 ± ² gf / cm ² )]. The fiber reinforced plastic layer forming material 21 is temporarily bonded to both surfaces of the polyethylene terephthalate foamed sheet 1 with an epoxy resin, and then a release film 3 (trade name “Oydis” manufactured by Kurabo Industries, special polystyrene resin film, thickness 50 μm) ) Was laminated on the fiber reinforced plastic layer forming material 21 to produce a laminate M (lamination step).

  Next, the polyethylene terephthalate foamed sheet 1 of the laminate M was gripped using clamps at the edges of the two opposite sides, while the fiber reinforced plastic layer forming material 21 was not gripped at all. Thereafter, the laminate M is heated for 30 seconds so that the surface temperature of the fiber reinforced plastic layer forming material 21 becomes 150 ° C., and the crystalline thermoplastic epoxy impregnated in the fiber reinforced plastic layer forming material 21 is impregnated. The resin was softened to a fluid state. In this state, the temporary adhesion between the polyethylene terephthalate foam sheet 1 and the fiber reinforced plastic layer forming material 21 is completely released, and the fiber reinforced plastic layer forming material 21 is freely movable on the polyethylene terephthalate foam sheet 1. It was.

  Subsequently, as shown in FIGS. 6 and 7, 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 for 1 minute, thereby pressing. The foamed sheet 1 of the laminate M was formed into a desired shape by molding, and the fiber-reinforced plastic layer forming material 21 was formed into a desired shape while sliding on the polyethylene terephthalate foamed sheet 1. At the time of press molding, the surface temperature of the fiber reinforced plastic layer forming material 21 of the laminate M is maintained at 110 ° C., and the thermoplastic epoxy resin contained in the fiber reinforced plastic layer forming material 21 maintains fluidity. Was controlled as follows.

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

  Next, after the laminate M was cooled until the surface temperature of the fiber reinforced plastic layer forming material 21 became 30 ° C. or less, the male and female molds 41 and 42 were opened to obtain a fiber reinforced composite A. The obtained fiber reinforced composite A has a fiber reinforced plastic layer 2 in which reinforced fibers are bound and fixed by a crystalline thermoplastic epoxy resin and formed into a desired shape along male and female molds 41 and 42. The thermoplastic thermoplastic epoxy resin was laminated and integrated so as to be in close contact with both sides of the thermoplastic polyester resin extruded foam sheet 1 along their surfaces.

(Example 13)
As a fiber reinforced plastic layer forming material before being laminated and integrated, a thermoplastic epoxy resin (glass transition temperature) is formed on a reinforced fiber base material formed from a satin weave made of glass fiber (trade name “WE181D” manufactured by Nitto Boseki Co., Ltd.). : 97 ° C.) impregnated with 40% by weight and a flat square fiber-reinforced plastic layer forming material (trade name “NNGF60-03s” manufactured by Nagase Chemtech Co., Ltd.) having a side of 250 mm, basis weight: 300 g / m ² , thickness: 0.3 mm ), The crimping surface temperature of the crimping tool when temporarily bonding the fiber reinforced plastic layer forming material 21 to both surfaces of the polyethylene terephthalate foamed sheet 1 is 100 ° C., and the fibers of the laminate M during press molding. The fiber reinforced composite A is the same as in Example 12, except that the surface temperature of the reinforced plastic layer forming material 21 is kept at 100 ° C. Obtained.

  The obtained fiber reinforced composite A has a fiber reinforced plastic layer 2 in which reinforced fibers are bound and fixed by a thermoplastic epoxy resin and formed into a desired shape along male and female molds 41 and 42. The resin was laminated and integrated in a state of being in close contact with both surfaces of the polyethylene terephthalate foamed sheet 1 along the surfaces thereof.

(Comparative Example 1)
An attempt was made to produce a fiber-reinforced composite in the same manner as in Example 1 except that a polypropylene foam sheet (PP, trade name “Microlen” manufactured by Sekisui Plastics Co., Ltd.) was used instead of the synthetic resin foam sheet. The foam sheet and the fiber reinforced plastic layer forming material were not integrated, and a fiber reinforced composite could not be obtained.

(Comparative Example 2)
A fiber-reinforced composite was obtained in the same manner as in Example 1 except that a polymethacrylimide foam sheet (PMI, trade name “Rohacel IG-51” manufactured by Daicel Evonik Co., Ltd.) was used as the synthetic resin foam. In addition, the non-foamed skin layer was removed from both surfaces of the polymethacrylimide foam sheet, and the cell cross section was exposed.

(Comparative Example 3)
As the synthetic resin foamed sheet, a polyethylene terephthalate foamed sheet having a mean square diameter, contact angle, tensile elongation at break, and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 2.5 mm was used. A fiber reinforced composite was obtained in the same manner as in Example 1 except that.

(Comparative Example 4)
As the synthetic resin foamed sheet, a polypropylene foamed sheet having a mean square diameter, contact angle, tensile elongation at break and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 0.6 mm was used. Except for the above, a fiber-reinforced composite was obtained in the same manner as in Example 12.

(Comparative Example 5)
As the synthetic resin foamed sheet, a polypropylene foamed sheet having a mean square diameter, contact angle, tensile elongation at break and apparent density shown in Table 1 having a square side of 16 cm and a thickness of 0.6 mm was used. Except for the above, a fiber-reinforced composite was obtained in the same manner as in Example 12.

  The resulting cell reinforced composite synthetic resin foam sheet was measured for average cell diameter, tensile elongation at break, thickness and apparent density, and the results are shown in Table 2. With respect to the fiber reinforced plastic layer of the obtained fiber reinforced composite, the content and thickness of the reinforced fiber were measured, and the results are shown in Table 2. About the obtained fiber reinforced composite, the whole thickness, the whole apparent density, the maximum point energy, and the specific absorption energy were measured in the following manner, and the results are shown in Table 2.

  The measurement of various physical properties of the fiber reinforced plastic foam sheet and fiber reinforced plastic layer was performed after separating the fiber reinforced composite foam sheet and the fiber reinforced plastic layer.

(Maximum point energy and specific absorption energy)
Five flat rectangular test pieces of 25 mm length × 150 mm width were cut out from the fiber reinforced composite. About each test piece, it measured based on JISK7221-1: 2006 "hard foam plastic-bending test-part 1: How to obtain | require a deflection characteristic" except the magnitude | size of a test piece. That is, the test piece was maintained for 16 hours or more in an environment of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%, and then measured in an environment of a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%. Using a Tensilon universal testing machine (trade name “UCT-10T” manufactured by Orientec Co., Ltd.) and a universal testing machine data processing software (trade name “UTPS-237S” manufactured by Softbrain Co., Ltd.), a compression speed of 10 mm / min, a pressure wedge Measurement was performed under the condition of a distance between fulcrums of 100 mm as 5R and a support base 5R. The number of test pieces was five.

  The specific absorbed energy was a value obtained by dividing the maximum point energy by the weight of the test piece. The arithmetic mean values of the maximum point energy and specific absorption energy of each test piece were taken as the maximum point energy and specific absorption energy. The maximum point energy is an index of impact resistance, and the larger the point energy, the better the impact resistance.

1 Synthetic resin foam sheet 2 Fiber reinforced plastic layer 3 Release film 4 Breather cloth 5 Bagging film
6a, 6b Press plate 7 Sealing material 8 Space
21 Fiber Reinforced Plastic Layer Forming Material A Fiber Reinforced Composite B Laminate

Claims (6)

A synthetic resin foam sheet having an average cell diameter of 10 to 400 μm and a contact angle of 30 to 82 °, and a fiber reinforced plastic layer laminated and integrated on one or both surfaces of the synthetic resin foam sheet Fiber reinforced composite. The fiber-reinforced composite according to claim 1, wherein the synthetic resin foam sheet has an elongation at break of 5 to 30%. The fiber-reinforced composite according to claim 1 or 2, wherein the synthetic resin foam sheet has a thickness of 0.1 to 5 mm. The fiber-reinforced composite according to any one of claims 1 to 3, wherein the content of reinforcing fibers in the fiber-reinforced plastic layer is 30 to 80% by weight. The fiber-reinforced composite according to any one of claims 1 to 4, wherein the synthetic resin foam sheet has an apparent density of 0.1 to 1.1 g / cm ³ . The fiber-reinforced composite according to any one of claims 1 to 5, wherein an apparent density is 0.3 to 1.5 g / cm ³ .

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